From 769a9767f7cfe0e8a7fce3cbef1968f764672e30 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 10:44:26 +0100
Subject: [PATCH 01/21] Restrict TF coil turn calculations to cable
 superconductors only

---
 process/models/tfcoil/superconducting.py | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 55a4737f89..b5eebb54ee 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -18,6 +18,7 @@
     N_CROCO_STRANDS_TURN,
     SuperconductorMaterial,
     SuperconductorModel,
+    SuperconductorShape,
     calculate_croco_cable_geometry,
 )
 from process.models.tfcoil import quench
@@ -2792,6 +2793,17 @@ def tf_cable_in_conduit_superconductor_properties(
         (i.e., the copper in the superconducting strands and any additional copper,
         such as REBCO tape support).
         """
+        if (
+            SuperconductorModel(i_tf_superconductor).sc_shape
+            != SuperconductorShape.CABLE
+        ):
+            raise ProcessValueError(
+                "Cannot calculate cable in conduit superconductor properties for "
+                "non-cable superconductors. Change `i_tf_sc_mat` to a cable "
+                "superconductor or use a different TF coil class for non-cable "
+                "superconductors."
+            )
+
         # Guard against negative conductor fraction f_a_tf_turn_cable_space_conductor
         # Kludge to allow solver to continue and hopefully be constrained away
         # from this point
@@ -2986,14 +2998,6 @@ def tf_cable_in_conduit_superconductor_properties(
 
         # =================================================================
 
-        # "REBCO" 2nd generation HTS superconductor in CrCo strand
-        elif i_tf_superconductor == SuperconductorModel.CROCO_REBCO:
-            raise ProcessValueError(
-                "sctfcoil.supercon has been called but data.tfcoil.i_tf_sc_mat=6"
-            )
-
-        # =================================================================
-
         # Durham Ginzburg-Landau Nb-Ti parameterisation
         elif i_tf_superconductor == SuperconductorModel.DURHAM_NBTI:
             bc20m = data.tfcoil.b_crit_upper_nbti  # [T]

From bd7557124b9737dafdeaa2a9a4d102dd8527fbd7 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 11:19:54 +0100
Subject: [PATCH 02/21] Initialize conductor parameters in
 SuperconductingTFData with default values

---
 .../superconducting_tf_coil_variables.py      | 30 +++++++++----------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/process/data_structure/superconducting_tf_coil_variables.py b/process/data_structure/superconducting_tf_coil_variables.py
index 285555102f..b69993fb9a 100644
--- a/process/data_structure/superconducting_tf_coil_variables.py
+++ b/process/data_structure/superconducting_tf_coil_variables.py
@@ -267,22 +267,22 @@ class SuperconductingTFData:
 
     # conductor
 
-    a_tf_turn_croco_cable_space_copper: float = None
-    conductor_copper_fraction: float = None
-    a_tf_turn_croco_copper_bar: float = None
+    a_tf_turn_croco_cable_space_copper: float = 0.0
+    conductor_copper_fraction: float = 0.0
+    a_tf_turn_croco_copper_bar: float = 0.0
     """Area of the central copper strand in the CroCo TF turn [m²]"""
-    a_tf_turn_croco_hastelloy: float = None
-    conductor_hastelloy_fraction: float = None
-    conductor_helium_area: float = None
-    conductor_helium_fraction: float = None
-    conductor_solder_area: float = None
-    conductor_solder_fraction: float = None
-    conductor_jacket_area: float = None
-    conductor_jacket_fraction: float = None
-    conductor_rebco_area: float = None
-    conductor_rebco_fraction: float = None
-    conductor_critical_current: float = None
-    conductor_area: float = None
+    a_tf_turn_croco_hastelloy: float = 0.0
+    conductor_hastelloy_fraction: float = 0.0
+    conductor_helium_area: float = 0.0
+    conductor_helium_fraction: float = 0.0
+    conductor_solder_area: float = 0.0
+    conductor_solder_fraction: float = 0.0
+    conductor_jacket_area: float = 0.0
+    conductor_jacket_fraction: float = 0.0
+    conductor_rebco_area: float = 0.0
+    conductor_rebco_fraction: float = 0.0
+    conductor_critical_current: float = 0.0
+    conductor_area: float = 0.0
     """Area of cable space inside jacket"""
 
     t1: float = 0.0

From be73adf239f5ca3859102ebd92f616307cad0354 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 11:33:29 +0100
Subject: [PATCH 03/21] Refactor CROCOSuperconductingTFCoil to streamline
 superconductor property calculations and remove deprecated models

---
 process/models/tfcoil/superconducting.py | 320 +++++++++++++----------
 1 file changed, 185 insertions(+), 135 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index b5eebb54ee..05d300d3c7 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -3026,86 +3026,6 @@ def tf_cable_in_conduit_superconductor_properties(
 
         # =================================================================
 
-        # Durham Ginzburg-Landau critical surface model for REBCO
-        elif i_tf_superconductor == SuperconductorModel.DURHAM_REBCO:
-            bc20m = 430  # [T]
-            tc0m = 185  # [K]
-
-            # If strain limit achieved, throw a warning and use the lower strain
-            if abs(strain) > 0.7e-2:
-                logger.error(
-                    f"TF strain={strain} was outside the region of applicability. "
-                    f"Used lower strain."
-                )
-                strain = np.sign(strain) * 0.7e-2
-
-            j_superconductor_critical, _, _ = superconductors.gl_rebco(
-                temp_conductor=temp_tf_coolant_peak_field,
-                b_conductor=b_tf_inboard_peak,
-                strain=strain,
-                b_c20max=bc20m,
-                t_c0=tc0m,
-            )
-            # Scale for the copper area fraction of the cable
-            j_cables_critical = j_superconductor_critical * (
-                1.0e0 - f_a_tf_turn_cable_copper
-            )
-
-            #  Critical current in turn all turn cables
-            c_turn_cables_critical = j_cables_critical * a_tf_turn_cable_space_effective
-
-            # Strand critical current calulation for costing in $ / kAm
-            # Already includes buffer and support layers so no need to include
-            # f_a_tf_turn_cable_copper here
-            data.tfcoil.j_crit_str_tf = j_superconductor_critical
-
-            # REBCO measurements from 2 T to 14 T, extrapolating outside this
-            if (b_tf_inboard_peak) >= 14.0:
-                logger.error(
-                    "Field on superconductor > 14 T (outside of interpolation range)"
-                )
-
-        # =================================================================
-
-        # Hazelton experimental data + Zhai conceptual model for REBCO
-        elif i_tf_superconductor == SuperconductorModel.HAZELTON_ZHAI_REBCO:
-            bc20m = 138  # [T]
-            tc0m = 92  # [K]
-
-            # If strain limit achieved, throw a warning and use the lower strain
-            if abs(strain) > 0.7e-2:
-                logger.error(
-                    f"TF strain={strain} was outside the region of applicability. "
-                    f"Used lower strain."
-                )
-                strain = np.sign(strain) * 0.7e-2
-
-            # 'high current density' as per parameterisation described in Wolf,
-            #  and based on Hazelton experimental data and Zhai conceptual model;
-            #  see subroutine for full references
-            j_superconductor_critical, _, _ = superconductors.hijc_rebco(
-                temp_conductor=temp_tf_coolant_peak_field,
-                b_conductor=b_tf_inboard_peak,
-                b_c20max=bc20m,
-                t_c0=tc0m,
-                dr_hts_tape=data.superconducting_tfcoil.dr_tf_hts_tape,
-                dx_hts_tape_rebco=data.superconducting_tfcoil.dx_tf_hts_tape_rebco,
-                dx_hts_tape_total=data.superconducting_tfcoil.dx_tf_hts_tape_total,
-            )
-            # Scale for the copper area fraction of the cable
-            j_cables_critical = j_superconductor_critical * (
-                1.0e0 - f_a_tf_turn_cable_copper
-            )
-
-            #  Critical current in turn all turn cables
-            c_turn_cables_critical = j_cables_critical * a_tf_turn_cable_space_effective
-
-            # Strand critical current calulation for costing in $ / kAm
-            # = superconducting filaments jc * (1 -strand copper fraction)
-            data.tfcoil.j_crit_str_tf = j_superconductor_critical * (
-                1.0e0 - f_a_tf_turn_cable_copper
-            )
-
         else:
             raise ProcessValueError(
                 "Illegal value for i_tf_sc_mat", i_tf_superconductor=i_tf_superconductor
@@ -4008,44 +3928,43 @@ def run(self, output: bool = False):
             * self.data.tfcoil.n_tf_coil_turns
         )
 
-        if (
-            SuperconductorModel(self.data.tfcoil.i_tf_sc_mat)
-            == SuperconductorModel.CROCO_REBCO
-        ):
-            superconductor_critical_properties = self.tf_croco_superconductor_properties(
-                a_tf_turn=self.data.tfcoil.a_tf_turn,
-                b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
-                cur_tf_turn=self.data.tfcoil.c_tf_turn,
-                temp_tf_peak=self.data.tfcoil.tftmp,
-            )
+        superconductor_critical_properties: TFSuperconductorLimits = self.tf_croco_superconductor_properties(
+            a_tf_turn=self.data.tfcoil.a_tf_turn,
+            b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
+            cur_tf_turn=self.data.tfcoil.c_tf_turn,
+            temp_tf_peak=self.data.tfcoil.tftmp,
+            a_tf_turn_cable_space_effective=self.data.superconducting_tfcoil.a_tf_turn_cable_space_effective,
+            i_tf_superconductor=self.data.tfcoil.i_tf_sc_mat,
+            dr_tf_hts_tape=self.data.superconducting_tfcoil.dr_tf_hts_tape,
+            dx_tf_hts_tape_rebco=self.data.superconducting_tfcoil.dx_tf_hts_tape_rebco,
+            dx_tf_hts_tape_total=self.data.superconducting_tfcoil.dx_tf_hts_tape_total,
+        )
 
-            self.data.tfcoil.j_tf_wp_critical = (
-                superconductor_critical_properties.j_tf_wp_critical
-            )
-            d_sc_tf.j_tf_superconductor_critical = (
-                superconductor_critical_properties.j_superconductor_critical
-            )
-            d_sc_tf.f_c_tf_turn_operating_critical = (
-                superconductor_critical_properties.f_c_tf_turn_operating_critical
-            )
-            d_sc_tf.j_tf_superconductor = (
-                superconductor_critical_properties.j_superconductor
-            )
-            d_sc_tf.j_tf_coil_turn = superconductor_critical_properties.j_tf_coil_turn
+        self.data.tfcoil.j_tf_wp_critical = (
+            superconductor_critical_properties.j_tf_wp_critical
+        )
+        self.data.superconducting_tfcoil.j_tf_superconductor_critical = (
+            superconductor_critical_properties.j_superconductor_critical
+        )
+        self.data.superconducting_tfcoil.f_c_tf_turn_operating_critical = (
+            superconductor_critical_properties.f_c_tf_turn_operating_critical
+        )
+        self.data.superconducting_tfcoil.j_tf_superconductor = (
+            superconductor_critical_properties.j_superconductor
+        )
+        self.data.superconducting_tfcoil.j_tf_coil_turn = (
+            superconductor_critical_properties.j_tf_coil_turn
+        )
 
-            d_sc_tf.b_tf_superconductor_critical_zero_temp_strain = (
-                superconductor_critical_properties.bc20m
-            )
-            d_sc_tf.temp_tf_superconductor_critical_zero_field_strain = (
-                superconductor_critical_properties.tc0m
-            )
-            d_sc_tf.c_tf_turn_cables_critical = (
-                superconductor_critical_properties.c_turn_cables_critical
-            )
+        self.data.superconducting_tfcoil.b_tf_superconductor_critical_zero_temp_strain = superconductor_critical_properties.bc20m
+        self.data.superconducting_tfcoil.temp_tf_superconductor_critical_zero_field_strain = superconductor_critical_properties.tc0m
+        self.data.superconducting_tfcoil.c_tf_turn_cables_critical = (
+            superconductor_critical_properties.c_turn_cables_critical
+        )
 
-            self.data.tfcoil.v_tf_coil_dump_quench_kv = (
-                self.croco_voltage() / 1.0e3
-            )  # TFC Quench voltage in kV
+        self.data.tfcoil.v_tf_coil_dump_quench_kv = (
+            self.croco_voltage() / 1.0e3
+        )  # TFC Quench voltage in kV
 
         # Negative areas or fractions error reporting
         if (
@@ -4415,33 +4334,160 @@ def tf_croco_superconductor_properties(
         b_tf_inboard_peak: float,
         cur_tf_turn: float,
         temp_tf_peak: float,
+        a_tf_turn_cable_space_effective: float,
+        i_tf_superconductor: int,
+        dr_tf_hts_tape: float,
+        dx_tf_hts_tape_rebco: float,
+        dx_tf_hts_tape_total: float,
     ) -> TFSuperconductorLimits:
         """TF superconducting CroCo conductor using REBCO tape
 
         Parameters
         ----------
         a_tf_turn :
-
+            Cross-sectional area of the TF turn (m²)
         b_tf_inboard_peak :
             Peak field at conductor (T)
         cur_tf_turn :
             Operating current per turn (A)
         temp_tf_peak :
-            He temperature at peak field point (K)
+            Coil temperature at peak field point (K)
+        a_tf_turn_cable_space_effective :
+            Effective cross-sectional area of the TF turn cable space (m²)
+        i_tf_superconductor :
+            Integer identifier for the superconductor material model to use.
+        dr_tf_hts_tape :
+            Thickness of the HTS tape (m)
+        dx_tf_hts_tape_rebco :
+            Width of the REBCO layer in the HTS tape (m)
+        dx_tf_hts_tape_total :
+            Total width of the HTS tape (m)
+
+        Returns
+        -------
+        TFSuperconductorLimits
+             A dataclass containing the calculated superconducting properties of the TF coil, including:
+            - j_tf_wp_critical: Critical current density in the TF winding pack (A/m²).
+            - j_superconductor_critical: Critical current density in the superconductor (A/m²).
+            - f_c_tf_turn_operating_critical: Ratio of operating current to critical current for the TF turn (dimensionless).
+            - j_tf_superconductor: Current density  in the superconductor at operating conditions (A/m²).
+            - j_tf_coil_turn: Current density in the TF coil turn at operating conditions (A/m²).
+            - bc20m: Critical magnetic field at 20 K and zero strain (T).
+            - tc0m: Critical temperature at zero magnetic field and zero strain (K).
+            - c_turn_cables_critical: Critical current in the TF turn cables (A).
 
         """
-        #  Find critical current density in superconducting cable, j_crit_cable
-        j_crit_sc, _, bc20m, tc0m = superconductors.jcrit_rebco(
-            temp_conductor=temp_tf_peak, b_conductor=b_tf_inboard_peak
-        )
+        if SuperconductorModel(i_tf_superconductor).sc_shape != SuperconductorShape.TAPE:
+            raise ProcessValueError(
+                "Cannot calculate tape superconductor properties for "
+                "non-tape superconductors. Change `i_tf_sc_mat` to a tape "
+                "superconductor or use a different TF coil class for non-tape "
+                "superconductors."
+            )
 
-        d_sc_tf = self.data.superconducting_tfcoil
+        if self.data.tfcoil.i_str_wp == 0:
+            strain = self.data.tfcoil.str_tf_con_res
+        else:
+            strain = self.data.tfcoil.str_wp
+
+        f_a_tf_turn_tape_superconductor = dx_tf_hts_tape_rebco / dx_tf_hts_tape_total
+
+        # =================================================================
+
+        if i_tf_superconductor == SuperconductorModel.CROCO_REBCO:
+            #  Find critical current density in superconducting cable, j_crit_cable
+            j_superconductor_critical, _, bc20m, tc0m = superconductors.jcrit_rebco(
+                temp_conductor=temp_tf_peak, b_conductor=b_tf_inboard_peak
+            )
+
+        # =================================================================
+
+        # Durham Ginzburg-Landau critical surface model for REBCO
+        elif i_tf_superconductor == SuperconductorModel.DURHAM_REBCO:
+            bc20m = 430  # [T]
+            tc0m = 185  # [K]
+
+            # If strain limit achieved, throw a warning and use the lower strain
+            if abs(strain) > 0.7e-2:
+                logger.error(
+                    f"TF strain={strain} was outside the region of applicability. "
+                    f"Used lower strain."
+                )
+                strain = np.sign(strain) * 0.7e-2
+
+            j_superconductor_critical, _, _ = superconductors.gl_rebco(
+                temp_conductor=temp_tf_peak,
+                b_conductor=b_tf_inboard_peak,
+                strain=strain,
+                b_c20max=bc20m,
+                t_c0=tc0m,
+            )
+            # Scale for the copper area fraction of the cable
+            j_tape_critical = j_superconductor_critical * f_a_tf_turn_tape_superconductor
+
+            #  Critical current in turn all turn cables
+            c_turn_cables_critical = j_tape_critical * a_tf_turn_cable_space_effective
+
+            # Strand critical current calulation for costing in $ / kAm
+            # Already includes buffer and support layers so no need to include
+            # f_a_tf_turn_cable_copper here
+            self.data.tfcoil.j_crit_str_tf = j_superconductor_critical
+
+            # REBCO measurements from 2 T to 14 T, extrapolating outside this
+            if (b_tf_inboard_peak) >= 14.0:
+                logger.error(
+                    "Field on superconductor > 14 T (outside of interpolation range)"
+                )
 
-        d_sc_tf.cur_tf_turn_croco_strand_critical = j_crit_sc * d_sc_tf.a_tf_croco_strand
+        # =================================================================
+
+        # Hazelton experimental data + Zhai conceptual model for REBCO
+        elif i_tf_superconductor == SuperconductorModel.HAZELTON_ZHAI_REBCO:
+            bc20m = 138  # [T]
+            tc0m = 92  # [K]
+
+            # If strain limit achieved, throw a warning and use the lower strain
+            if abs(strain) > 0.7e-2:
+                logger.error(
+                    f"TF strain={strain} was outside the region of applicability. "
+                    f"Used lower strain."
+                )
+                strain = np.sign(strain) * 0.7e-2
+
+            # 'high current density' as per parameterisation described in Wolf,
+            #  and based on Hazelton experimental data and Zhai conceptual model;
+            #  see subroutine for full references
+            j_superconductor_critical, _, _ = superconductors.hijc_rebco(
+                temp_conductor=temp_tf_peak,
+                b_conductor=b_tf_inboard_peak,
+                b_c20max=bc20m,
+                t_c0=tc0m,
+                dr_hts_tape=dr_tf_hts_tape,
+                dx_hts_tape_rebco=dx_tf_hts_tape_rebco,
+                dx_hts_tape_total=dx_tf_hts_tape_total,
+            )
+            # Scale for the copper area fraction of the cable
+            j_tape_critical = j_superconductor_critical * f_a_tf_turn_tape_superconductor
+
+            #  Critical current in turn all turn cables
+            c_turn_cables_critical = j_tape_critical * a_tf_turn_cable_space_effective
+
+            # Strand critical current calulation for costing in $ / kAm
+            # = superconducting filaments jc * (1 -strand copper fraction)
+            self.data.tfcoil.j_crit_str_tf = (
+                j_superconductor_critical * f_a_tf_turn_tape_superconductor
+            )
+
+        # =================================================================
+
+        cur_tf_turn_croco_strand_critical = (
+            j_superconductor_critical
+            * self.data.superconducting_tfcoil.a_tf_croco_strand
+        )
 
         # Conductor properties
-        d_sc_tf.conductor_critical_current = (
-            d_sc_tf.cur_tf_turn_croco_strand_critical * N_CROCO_STRANDS_TURN
+        self.data.superconducting_tfcoil.conductor_critical_current = (
+            cur_tf_turn_croco_strand_critical * N_CROCO_STRANDS_TURN
         )
 
         d_sc_tf.tf_coppera_m2 = cur_tf_turn / d_sc_tf.a_tf_turn_croco_cable_space_copper
@@ -4451,18 +4497,22 @@ def tf_croco_superconductor_properties(
         # Critical current density in winding pack
         # a_tf_turn : Area per turn (i.e. entire jacketed conductor with insulation) (m2)
         j_tf_wp_critical = cur_critical / a_tf_turn
+
         #  Ratio of operating / critical current
-        iooic = cur_tf_turn / cur_critical
+        f_c_tf_turn_operating_critical = cur_tf_turn / cur_critical
+
         #  Operating current density
-        jwdgop = cur_tf_turn / a_tf_turn
+        j_tf_coil_turn = cur_tf_turn / a_tf_turn
+
         #  Actual current density in superconductor,
         # which should be equal to jcrit(thelium+tmarg)
-
         #  when we have found the desired value of tmarg
-        jsc = iooic * j_crit_sc
+        j_superconductor = f_c_tf_turn_operating_critical * j_superconductor_critical
 
         # Temperature margin
-        current_sharing_t = superconductors.current_sharing_rebco(b_tf_inboard_peak, jsc)
+        current_sharing_t = superconductors.current_sharing_rebco(
+            b_tf_inboard_peak, j_superconductor
+        )
         tmarg = current_sharing_t - temp_tf_peak
         self.data.tfcoil.temp_margin = (
             tmarg  # Only used in the availabilty routine - see comment to Issue #526
@@ -4470,13 +4520,13 @@ def tf_croco_superconductor_properties(
 
         return TFSuperconductorLimits(
             j_tf_wp_critical=j_tf_wp_critical,
-            j_superconductor_critical=j_crit_sc,
-            f_c_tf_turn_operating_critical=iooic,
-            j_superconductor=jsc,
-            j_tf_coil_turn=jwdgop,
+            j_superconductor_critical=j_superconductor_critical,
+            f_c_tf_turn_operating_critical=f_c_tf_turn_operating_critical,
+            j_superconductor=j_superconductor,
+            j_tf_coil_turn=j_tf_coil_turn,
             bc20m=bc20m,
             tc0m=tc0m,
-            c_turn_cables_critical=d_sc_tf.cur_tf_turn_croco_strand_critical,
+            c_turn_cables_critical=cur_tf_turn_croco_strand_critical,
         )
 
     @staticmethod

From 82a45a12f95fc5ccfd4b99238d55dc12264caeee Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 12:03:20 +0100
Subject: [PATCH 04/21] Refactor CROCOSuperconductingTFCoil to optimize
 critical current calculations and improve code clarity

---
 process/models/tfcoil/superconducting.py | 42 +++++++++---------------
 1 file changed, 16 insertions(+), 26 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 05d300d3c7..a9ba6c02ba 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -4422,22 +4422,6 @@ def tf_croco_superconductor_properties(
                 b_c20max=bc20m,
                 t_c0=tc0m,
             )
-            # Scale for the copper area fraction of the cable
-            j_tape_critical = j_superconductor_critical * f_a_tf_turn_tape_superconductor
-
-            #  Critical current in turn all turn cables
-            c_turn_cables_critical = j_tape_critical * a_tf_turn_cable_space_effective
-
-            # Strand critical current calulation for costing in $ / kAm
-            # Already includes buffer and support layers so no need to include
-            # f_a_tf_turn_cable_copper here
-            self.data.tfcoil.j_crit_str_tf = j_superconductor_critical
-
-            # REBCO measurements from 2 T to 14 T, extrapolating outside this
-            if (b_tf_inboard_peak) >= 14.0:
-                logger.error(
-                    "Field on superconductor > 14 T (outside of interpolation range)"
-                )
 
         # =================================================================
 
@@ -4466,19 +4450,25 @@ def tf_croco_superconductor_properties(
                 dx_hts_tape_rebco=dx_tf_hts_tape_rebco,
                 dx_hts_tape_total=dx_tf_hts_tape_total,
             )
-            # Scale for the copper area fraction of the cable
-            j_tape_critical = j_superconductor_critical * f_a_tf_turn_tape_superconductor
 
-            #  Critical current in turn all turn cables
-            c_turn_cables_critical = j_tape_critical * a_tf_turn_cable_space_effective
+        # =================================================================
 
-            # Strand critical current calulation for costing in $ / kAm
-            # = superconducting filaments jc * (1 -strand copper fraction)
-            self.data.tfcoil.j_crit_str_tf = (
-                j_superconductor_critical * f_a_tf_turn_tape_superconductor
-            )
+        # Scale for the copper area fraction of the cable
+        j_tape_critical = j_superconductor_critical * f_a_tf_turn_tape_superconductor
 
-        # =================================================================
+        #  Critical current in turn all turn cables
+        c_turn_cables_critical = j_tape_critical * a_tf_turn_cable_space_effective
+
+        # Strand critical current calulation for costing in $ / kAm
+        # Already includes buffer and support layers so no need to include
+        # f_a_tf_turn_cable_copper here
+        self.data.tfcoil.j_crit_str_tf = j_superconductor_critical
+
+        # REBCO measurements from 2 T to 14 T, extrapolating outside this
+        if (b_tf_inboard_peak) >= 14.0:
+            logger.error(
+                "Field on superconductor > 14 T (outside of interpolation range)"
+            )
 
         cur_tf_turn_croco_strand_critical = (
             j_superconductor_critical

From 5d4f1b64854d850aa7eec0e84459b50f8cb2459b Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 13:42:41 +0100
Subject: [PATCH 05/21] Enhance TF coil plots by adding critical current
 density and field information

---
 process/core/io/plot/summary.py   |  4 ++++
 process/models/superconductors.py | 10 +++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/process/core/io/plot/summary.py b/process/core/io/plot/summary.py
index e92d96ff09..573c143cb8 100644
--- a/process/core/io/plot/summary.py
+++ b/process/core/io/plot/summary.py
@@ -7527,6 +7527,8 @@ def _pack_strands_rectangular_with_obstacles(
         f"Critical field at zero \ntemperature and strain: {mfile.get('b_tf_superconductor_critical_zero_temp_strain', scan=scan):.4f} T\n"
         f"Critical temperature at \nzero field and strain: {mfile.get('temp_tf_superconductor_critical_zero_field_strain', scan=scan):.4f} K\n"
         f"Temperature at conductor: {mfile.get('tftmp', scan=scan):.4f} K\n"
+        f"Field at conductor: {mfile.get('b_tf_inboard_peak_with_ripple', scan=scan):.4f} T\n"
+        f"Superconductor critical current density at \noperating conditions: {mfile.get('j_tf_superconductor_critical', scan=scan):.2e} A/m$^2$\n"
         f"$I_{{\\text{{TF,turn critical}}}}$: {mfile.get('c_turn_cables_critical', scan=scan):,.2f} A\n"
         f"$I_{{\\text{{TF,turn}}}}$: {mfile.get('c_tf_turn', scan=scan):,.2f} A\n"
         f"Critcal current ratio: {mfile.get('f_c_tf_turn_operating_critical', scan=scan):,.4f}\n"
@@ -7805,6 +7807,8 @@ def plot_tf_croco_turn(axis: plt.Axes, fig, mfile: MFile, scan: int):
         f"Critical field at zero \ntemperature and strain: {mfile.get('b_tf_superconductor_critical_zero_temp_strain', scan=scan):.4f} T\n"
         f"Critical temperature at \nzero field and strain: {mfile.get('temp_tf_superconductor_critical_zero_field_strain', scan=scan):.4f} K\n"
         f"Temperature at conductor: {mfile.get('tftmp', scan=scan):.4f} K\n"
+        f"Field at conductor: {mfile.get('b_tf_inboard_peak_with_ripple', scan=scan):.4f} T\n"
+        f"Superconductor critical current density at \noperating conditions: {mfile.get('j_tf_superconductor_critical', scan=scan):.2e} A/m$^2$\n"
         f"$I_{{\\text{{TF,turn critical}}}}$: {mfile.get('c_turn_cables_critical', scan=scan):,.2f} A\n"
         f"$I_{{\\text{{TF,turn}}}}$: {mfile.get('c_tf_turn', scan=scan):,.2f} A\n"
         f"Critcal current ratio: {mfile.get('f_c_tf_turn_operating_critical', scan=scan):,.4f}\n"
diff --git a/process/models/superconductors.py b/process/models/superconductors.py
index 20a93374fd..d4e5c9f675 100644
--- a/process/models/superconductors.py
+++ b/process/models/superconductors.py
@@ -814,34 +814,34 @@ def hijc_rebco(
     # finding A(T); constants based on a Newton polynomial fit to pubished data
     a_t = a_0 + (u * temp_conductor**2) + (v * temp_conductor)
 
-    # Critical current density (A/m2)
+    # Critical current
     # In the original formula bcrit must be > bmax to prevent NaNs.
     # However, negative jcrit is permissible (I think).
     # So when bcrit < bmax, I reverse the sign of the bracket,
     # giving a negative but real value of jcrit.
 
     if b_critical > b_conductor:
-        j_critical = (
+        cur_critical = (
             (a_t / b_conductor)
             * b_critical**b
             * (b_conductor / b_critical) ** p
             * (1 - b_conductor / b_critical) ** q
         )
     else:
-        j_critical = (
+        cur_critical = (
             (a_t / b_conductor)
             * b_critical**b
             * (b_conductor / b_critical) ** p
             * (b_conductor / b_critical - 1) ** q
         )
 
-    # Jc times HTS area: default area is width 4mm times HTS layer thickness 1 um,
+    # Critical current times HTS area: default area is width 4mm times HTS layer thickness 1 um,
     # divided by the tape area to provide engineering Jc per tape,!
     # A scaling factor of 0.4 used to be applied below to assume the difference
     # between tape stacks and CORC cable layouts.
 
     j_critical = (
-        j_critical
+        cur_critical
         * (dr_hts_tape * dx_hts_tape_rebco)
         / (dr_hts_tape * dx_hts_tape_total)
     )

From 5a3db89248d876cbabe11c341c31f62b5222360c Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 14:03:23 +0100
Subject: [PATCH 06/21] Add output for peak inboard toroidal field with ripple
 in SuperconductingTFCoil

---
 process/models/tfcoil/superconducting.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index a9ba6c02ba..ea1bf28b43 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -890,6 +890,13 @@ def output_tf_superconductor_info(self):
             "(tftmp)",
             self.data.tfcoil.tftmp,
         )
+        po.ovarre(
+            self.outfile,
+            "Peak inboard toroidal field including ripple (T)",
+            "(b_tf_inboard_peak_with_ripple)",
+            self.data.tfcoil.b_tf_inboard_peak_with_ripple,
+        )
+        po.oblnkl(self.outfile)
         po.ovarre(
             self.outfile,
             "Total cooling area fraction inside cable space",

From e5f5ad9f323021f21e3930f2c824a19c2b6e7ff2 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 16:04:10 +0100
Subject: [PATCH 07/21] Add copper area calculations and update related
 attributes in CROCOSuperconductingTFCoil

---
 .../superconducting_tf_coil_variables.py      | 11 +++-
 process/models/tfcoil/superconducting.py      | 65 +++++++++----------
 2 files changed, 40 insertions(+), 36 deletions(-)

diff --git a/process/data_structure/superconducting_tf_coil_variables.py b/process/data_structure/superconducting_tf_coil_variables.py
index b69993fb9a..3aa485ecef 100644
--- a/process/data_structure/superconducting_tf_coil_variables.py
+++ b/process/data_structure/superconducting_tf_coil_variables.py
@@ -268,9 +268,18 @@ class SuperconductingTFData:
     # conductor
 
     a_tf_turn_croco_cable_space_copper: float = 0.0
-    conductor_copper_fraction: float = 0.0
+    """Area of the copper in the CroCo cable space of the TF turn (includes tapes,
+    outer tube and central copper) (m²)"""
+
+    a_tf_turn_copper_total: float = 0.0
+    """Area of all copper in the TF turn (m²)"""
+
+    f_a_tf_turn_copper: float = 0.0
+    """Fraction of the TF turn area that is copper (m²)"""
+
     a_tf_turn_croco_copper_bar: float = 0.0
     """Area of the central copper strand in the CroCo TF turn [m²]"""
+
     a_tf_turn_croco_hastelloy: float = 0.0
     conductor_hastelloy_fraction: float = 0.0
     conductor_helium_area: float = 0.0
diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index ea1bf28b43..3bbed8c2fc 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -3896,8 +3896,25 @@ def run(self, output: bool = False):
             d_sc_tf.a_tf_croco_strand_copper_total * N_CROCO_STRANDS_TURN
             + d_sc_tf.a_tf_turn_croco_copper_bar
         )
-        d_sc_tf.conductor_copper_fraction = (
-            d_sc_tf.a_tf_turn_croco_cable_space_copper / d_sc_tf.conductor_area
+
+        self.data.superconducting_tfcoil.a_tf_turn_copper_total = (
+            self.data.superconducting_tfcoil.a_tf_turn_croco_cable_space_copper
+        )
+
+        self.data.superconducting_tfcoil.f_a_tf_turn_copper = (
+            self.data.superconducting_tfcoil.a_tf_turn_croco_cable_space_copper
+            / self.data.tfcoil.a_tf_turn
+        )
+
+        self.data.superconducting_tfcoil.f_a_tf_turn_cable_space_cooling = (
+            self.data.tfcoil.a_tf_turn_cable_space_no_void
+            - (
+                (
+                    N_CROCO_STRANDS_TURN
+                    * self.data.superconducting_tfcoil.a_tf_croco_strand
+                )
+                - self.data.superconducting_tfcoil.a_tf_turn_croco_copper_bar
+            )
         )
 
         # Helium area is set by the user.
@@ -3945,6 +3962,7 @@ def run(self, output: bool = False):
             dr_tf_hts_tape=self.data.superconducting_tfcoil.dr_tf_hts_tape,
             dx_tf_hts_tape_rebco=self.data.superconducting_tfcoil.dx_tf_hts_tape_rebco,
             dx_tf_hts_tape_total=self.data.superconducting_tfcoil.dx_tf_hts_tape_total,
+            a_tf_croco_strand=self.data.superconducting_tfcoil.a_tf_croco_strand,
         )
 
         self.data.tfcoil.j_tf_wp_critical = (
@@ -4346,6 +4364,7 @@ def tf_croco_superconductor_properties(
         dr_tf_hts_tape: float,
         dx_tf_hts_tape_rebco: float,
         dx_tf_hts_tape_total: float,
+        a_tf_croco_strand: float,
     ) -> TFSuperconductorLimits:
         """TF superconducting CroCo conductor using REBCO tape
 
@@ -4477,10 +4496,7 @@ def tf_croco_superconductor_properties(
                 "Field on superconductor > 14 T (outside of interpolation range)"
             )
 
-        cur_tf_turn_croco_strand_critical = (
-            j_superconductor_critical
-            * self.data.superconducting_tfcoil.a_tf_croco_strand
-        )
+        cur_tf_turn_croco_strand_critical = j_superconductor_critical * a_tf_croco_strand
 
         # Conductor properties
         self.data.superconducting_tfcoil.conductor_critical_current = (
@@ -4717,27 +4733,6 @@ def output_croco_info(self) -> None:
             d_sc_tf.a_tf_croco_strand_solder,
             "OP ",
         )
-        po.ovarre(
-            self.outfile,
-            "Total: area of CroCo strand (m²)  ",
-            "(a_tf_croco_strand)",
-            d_sc_tf.a_tf_croco_strand,
-            "OP ",
-        )
-        if (
-            abs(
-                d_sc_tf.a_tf_croco_strand
-                - (
-                    d_sc_tf.a_tf_croco_strand_rebco
-                    + d_sc_tf.a_tf_croco_strand_copper_total
-                    + d_sc_tf.a_tf_croco_strand_hastelloy
-                    + d_sc_tf.a_tf_croco_strand_solder
-                )
-            )
-            > 1e-6
-        ):
-            po.ocmmnt(self.outfile, "ERROR: Areas in CroCo strand do not add up")
-            logger.error("Areas in CroCo strand do not add up - see OUT.DAT")
 
         po.oblnkl(self.outfile)
         po.ocmmnt(self.outfile, "Cable information")
@@ -4770,8 +4765,8 @@ def output_croco_info(self) -> None:
         po.ovarre(
             self.outfile,
             "Area of conductor (m²)",
-            "(area)",
-            d_sc_tf.conductor_area,
+            "(conductor_area)",
+            self.data.superconducting_tfcoil.conductor_area,
             "OP ",
         )
         po.ovarre(
@@ -4784,22 +4779,22 @@ def output_croco_info(self) -> None:
         po.ovarre(
             self.outfile,
             "Area of central copper bar (m²)",
-            "(copper_bar_area)",
-            d_sc_tf.a_tf_turn_croco_copper_bar,
+            "(a_tf_turn_croco_copper_bar)",
+            self.data.superconducting_tfcoil.a_tf_turn_croco_copper_bar,
             "OP ",
         )
         po.ovarre(
             self.outfile,
             "Total copper area of conductor, total (m²)",
-            "(a_tf_croco_strand_copper_total)",
-            d_sc_tf.a_tf_turn_croco_cable_space_copper,
+            "(a_tf_turn_croco_cable_space_copper)",
+            self.data.superconducting_tfcoil.a_tf_turn_croco_cable_space_copper,
             "OP ",
         )
         po.ovarre(
             self.outfile,
             "Hastelloy area of conductor (m²)",
-            "(a_tf_croco_strand_hastelloy)",
-            d_sc_tf.a_tf_turn_croco_hastelloy,
+            "(a_tf_turn_croco_hastelloy)",
+            self.data.superconducting_tfcoil.a_tf_turn_croco_hastelloy,
             "OP ",
         )
         po.ovarre(

From b51acb20eb56bc362f1ac19dc6ac50f69e79bdac Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 16:15:25 +0100
Subject: [PATCH 08/21] Refactor CROCOSuperconductingTFCoil to remove unused
 helium area calculations and add fraction of superconducting material area

---
 .../superconducting_tf_coil_variables.py      | 10 ++++-----
 process/models/tfcoil/superconducting.py      | 21 ++++---------------
 2 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/process/data_structure/superconducting_tf_coil_variables.py b/process/data_structure/superconducting_tf_coil_variables.py
index 3aa485ecef..ad69d229f3 100644
--- a/process/data_structure/superconducting_tf_coil_variables.py
+++ b/process/data_structure/superconducting_tf_coil_variables.py
@@ -259,14 +259,9 @@ class SuperconductingTFData:
     a_tf_croco_strand: float = 0.0
     """Total area of a CroCo strand (m²)"""
 
-    # croco_strand
-
-    tf_croco_strand_area: float = 0.0
     cur_tf_turn_croco_strand_critical: float = 0.0
     """Critical current in the TF turn CroCo strand (A)"""
 
-    # conductor
-
     a_tf_turn_croco_cable_space_copper: float = 0.0
     """Area of the copper in the CroCo cable space of the TF turn (includes tapes,
     outer tube and central copper) (m²)"""
@@ -280,7 +275,12 @@ class SuperconductingTFData:
     a_tf_turn_croco_copper_bar: float = 0.0
     """Area of the central copper strand in the CroCo TF turn [m²]"""
 
+    f_a_tf_turn_superconductor: float = 0.0
+    """Fraction of the TF turn area that is superconducting material [m²]"""
+
     a_tf_turn_croco_hastelloy: float = 0.0
+    """Area of the Hastelloy in the CroCo cable space of the TF turn (includes tapes and outer tube) (m²)"""
+
     conductor_hastelloy_fraction: float = 0.0
     conductor_helium_area: float = 0.0
     conductor_helium_fraction: float = 0.0
diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 3bbed8c2fc..d31fd53f23 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -3915,14 +3915,7 @@ def run(self, output: bool = False):
                 )
                 - self.data.superconducting_tfcoil.a_tf_turn_croco_copper_bar
             )
-        )
-
-        # Helium area is set by the user.
-        # conductor_helium_area = cable_helium_fraction * self.data.tfcoil.a_tf_turn_cable_space_no_void  # noqa: E501
-        d_sc_tf.conductor_helium_area = np.pi / 2.0 * d_sc_tf.dia_tf_turn_croco_cable**2
-        d_sc_tf.conductor_helium_fraction = (
-            d_sc_tf.conductor_helium_area / d_sc_tf.conductor_area
-        )
+        ) / self.data.tfcoil.a_tf_turn_cable_space_no_void
 
         d_sc_tf.a_tf_turn_croco_hastelloy = (
             d_sc_tf.a_tf_croco_strand_hastelloy * N_CROCO_STRANDS_TURN
@@ -3941,8 +3934,9 @@ def run(self, output: bool = False):
         d_sc_tf.conductor_rebco_area = (
             d_sc_tf.a_tf_croco_strand_rebco * N_CROCO_STRANDS_TURN
         )
-        d_sc_tf.conductor_rebco_fraction = (
-            d_sc_tf.conductor_rebco_area / d_sc_tf.conductor_area
+        self.data.superconducting_tfcoil.f_a_tf_turn_superconductor = (
+            self.data.superconducting_tfcoil.conductor_rebco_area
+            / self.data.superconducting_tfcoil.conductor_area
         )
 
         # Cross-sectional area per turn
@@ -4811,13 +4805,6 @@ def output_croco_info(self) -> None:
             d_sc_tf.conductor_jacket_area,
             "OP ",
         )
-        po.ovarre(
-            self.outfile,
-            "Helium area of conductor (m²)",
-            "(helium_area)",
-            d_sc_tf.conductor_helium_area,
-            "OP ",
-        )
 
         po.ovarre(
             self.outfile,

From c552f9cf7a631344c9a760a05637160358043dd1 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 16:36:42 +0100
Subject: [PATCH 09/21] Refactor CROCOSuperconductingTFCoil to update conductor
 area calculations and remove unused void area logic

---
 process/models/tfcoil/superconducting.py | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index d31fd53f23..8ef7ad7960 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -3783,15 +3783,6 @@ def run(self, output: bool = False):
         # No central channel in CroCo conductor,
         self.data.tfcoil.a_tf_wp_coolant_channels = 0.0
 
-        # Total conductor cross-sectional area, taking account of void area
-        # and central helium channel [m²]
-        self.data.tfcoil.a_tf_wp_conductor = (
-            self.data.tfcoil.a_tf_turn_cable_space_no_void
-            * self.data.tfcoil.n_tf_coil_turns
-            * (1.0e0 - self.data.tfcoil.f_a_tf_turn_cable_space_extra_void)
-            - self.data.tfcoil.a_tf_wp_coolant_channels
-        )
-
         # Void area in conductor for He, not including central channel [m²]
         self.data.tfcoil.a_tf_wp_extra_void = (
             self.data.tfcoil.a_tf_turn_cable_space_no_void
@@ -3897,6 +3888,12 @@ def run(self, output: bool = False):
             + d_sc_tf.a_tf_turn_croco_copper_bar
         )
 
+        # Total conductor cross-sectional area, taking account of void area
+        # and central helium channel [m²]
+        self.data.tfcoil.a_tf_wp_conductor = (
+            N_CROCO_STRANDS_TURN * self.data.superconducting_tfcoil.a_tf_croco_strand
+        ) * self.data.tfcoil.n_tf_coil_turns
+
         self.data.superconducting_tfcoil.a_tf_turn_copper_total = (
             self.data.superconducting_tfcoil.a_tf_turn_croco_cable_space_copper
         )

From 490deca68bd2e1c4536e5a6b7ca64f15de576b2b Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 16:46:28 +0100
Subject: [PATCH 10/21] Refactor TF coil variables to rename conductor width to
 conduit full average and update related calculations

---
 process/core/io/obsolete_vars.py           |   2 +-
 process/data_structure/tfcoil_variables.py |   4 +-
 process/models/tfcoil/superconducting.py   | 138 ++++++++++++++-------
 tests/unit/models/tfcoil/test_sctfcoil.py  |  20 +--
 4 files changed, 106 insertions(+), 58 deletions(-)

diff --git a/process/core/io/obsolete_vars.py b/process/core/io/obsolete_vars.py
index 2b34765c7e..7877a6bb48 100644
--- a/process/core/io/obsolete_vars.py
+++ b/process/core/io/obsolete_vars.py
@@ -49,7 +49,7 @@
     "thkwp": "dr_tf_wp_with_insulation",
     "leni": "dx_tf_turn_cable_space_average",
     "leno": "t_turn",
-    "conductor_width": "t_conductor",
+    "conductor_width": "dx_tf_turn_conduit_full_average",
     "deltf": "dr_tf_shld_gap",
     "ddwi": "dr_vv_outboard",
     "pnuccp": "pnuc_cp",
diff --git a/process/data_structure/tfcoil_variables.py b/process/data_structure/tfcoil_variables.py
index e15d317a3b..9091b3f6fb 100644
--- a/process/data_structure/tfcoil_variables.py
+++ b/process/data_structure/tfcoil_variables.py
@@ -95,8 +95,8 @@ class TFData:
     tfc_sidewall_is_fraction: bool = False
     """logical switch to make dx_tf_side_case_min a fraction of TF coil thickness (`casths_fraction`)"""
 
-    t_conductor: float = 0.0
-    """Conductor (cable + steel conduit) area averaged dimension [m]"""
+    dx_tf_turn_conduit_full_average: float = 0.0
+    """Average full width of the conduit surrounding the TF turn cable space [m]"""
 
     dx_tf_turn_general: float = 0.0
     """TF coil turn edge length including turn insulation [m]
diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 8ef7ad7960..9c7dc72273 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -610,14 +610,14 @@ def output_general_superconducting_tf_info(self) -> None:
             )
             po.ovarre(
                 self.outfile,
-                "Width of conductor (square) (m)",
-                "(t_conductor)",
-                self.data.tfcoil.t_conductor,
+                "Width of conduit surrounding cable space (square) (m)",
+                "(dx_tf_turn_conduit_full_average)",
+                self.data.tfcoil.dx_tf_turn_conduit_full_average,
                 "OP ",
             )
             po.ovarre(
                 self.outfile,
-                "Width of space inside conductor (m)",
+                "Width of cable space inside conduit (m)",
                 "(dx_tf_turn_cable_space_average)",
                 d_sc_tf.dx_tf_turn_cable_space_average,
                 "OP ",
@@ -2195,7 +2195,7 @@ class CICCAveragedTurnGeometry:
     dx_tf_turn_general: float
     dr_tf_turn: float
     dx_tf_turn: float
-    t_conductor: float
+    dx_tf_turn_conduit_full_average: float
     radius_tf_turn_cable_space_corners: float
     dx_tf_turn_cable_space_average: float
     a_tf_turn_cable_space_effective: float
@@ -2216,7 +2216,7 @@ class CICCIntegerTurnGeometry:
     n_tf_coil_turns: int
     t_conductor_radial: float
     t_conductor_toroidal: float
-    t_conductor: float
+    dx_tf_turn_conduit_full_average: float
     dr_tf_turn_cable_space: float
     dx_tf_turn_cable_space: float
     dx_tf_turn_cable_space_average: float
@@ -2269,10 +2269,12 @@ def run(self, output: bool = False):
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
             self.data.tfcoil.c_tf_turn = avg_turn_geometry.c_tf_turn
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
-            d_sc_tf.dr_tf_turn = avg_turn_geometry.dr_tf_turn
-            d_sc_tf.dx_tf_turn = avg_turn_geometry.dx_tf_turn
-            self.data.tfcoil.t_conductor = avg_turn_geometry.t_conductor
-            d_sc_tf.radius_tf_turn_cable_space_corners = (
+            self.data.superconducting_tfcoil.dr_tf_turn = avg_turn_geometry.dr_tf_turn
+            self.data.superconducting_tfcoil.dx_tf_turn = avg_turn_geometry.dx_tf_turn
+            self.data.tfcoil.dx_tf_turn_conduit_full_average = (
+                avg_turn_geometry.dx_tf_turn_conduit_full_average
+            )
+            self.data.superconducting_tfcoil.radius_tf_turn_cable_space_corners = (
                 avg_turn_geometry.radius_tf_turn_cable_space_corners
             )
             d_sc_tf.dx_tf_turn_cable_space_average = (
@@ -2314,12 +2316,22 @@ def run(self, output: bool = False):
             )
             self.data.tfcoil.c_tf_turn = int_turn_geometry.c_tf_turn
             self.data.tfcoil.n_tf_coil_turns = int_turn_geometry.n_tf_coil_turns
-            d_sc_tf.t_conductor_radial = int_turn_geometry.t_conductor_radial
-            d_sc_tf.t_conductor_toroidal = int_turn_geometry.t_conductor_toroidal
-            self.data.tfcoil.t_conductor = int_turn_geometry.t_conductor
-            d_sc_tf.dr_tf_turn_cable_space = int_turn_geometry.dr_tf_turn_cable_space
-            d_sc_tf.dx_tf_turn_cable_space = int_turn_geometry.dx_tf_turn_cable_space
-            d_sc_tf.dx_tf_turn_cable_space_average = (
+            self.data.superconducting_tfcoil.t_conductor_radial = (
+                int_turn_geometry.t_conductor_radial
+            )
+            self.data.superconducting_tfcoil.t_conductor_toroidal = (
+                int_turn_geometry.t_conductor_toroidal
+            )
+            self.data.tfcoil.dx_tf_turn_conduit_full_average = (
+                int_turn_geometry.dx_tf_turn_conduit_full_average
+            )
+            self.data.superconducting_tfcoil.dr_tf_turn_cable_space = (
+                int_turn_geometry.dr_tf_turn_cable_space
+            )
+            self.data.superconducting_tfcoil.dx_tf_turn_cable_space = (
+                int_turn_geometry.dx_tf_turn_cable_space
+            )
+            self.data.superconducting_tfcoil.dx_tf_turn_cable_space_average = (
                 int_turn_geometry.dx_tf_turn_cable_space_average
             )
 
@@ -3260,7 +3272,7 @@ def tf_cable_in_conduit_averaged_turn_geometry(
         # See derivation in the following document
         # k:\power plant physics and technology\process\hts\hts coil module
         # for process.docx
-        t_conductor = (
+        dx_tf_turn_conduit_full_average = (
             -layer_ins + np.sqrt(layer_ins**2 + 4.0e00 * a_tf_turn)
         ) / 2 - 2.0e0 * dx_tf_turn_insulation
 
@@ -3268,13 +3280,15 @@ def tf_cable_in_conduit_averaged_turn_geometry(
         n_tf_coil_turns = a_tf_wp_no_insulation / a_tf_turn
 
         # Area of inter-turn insulation: single turn [m2]
-        a_tf_turn_insulation = a_tf_turn - t_conductor**2
+        a_tf_turn_insulation = a_tf_turn - dx_tf_turn_conduit_full_average**2
 
         # Radius of rounded corners of cable space inside conduit [m]
         radius_tf_turn_cable_space_corners = dx_tf_turn_steel * 0.75e0
 
         # Dimension of square cable space inside conduit [m]
-        dx_tf_turn_cable_space_average = t_conductor - 2.0e0 * dx_tf_turn_steel
+        dx_tf_turn_cable_space_average = (
+            dx_tf_turn_conduit_full_average - 2.0e0 * dx_tf_turn_steel
+        )
 
         # Cross-sectional area of cable space per turn
         # taking account of rounded inside corners [m2]
@@ -3300,7 +3314,7 @@ def tf_cable_in_conduit_averaged_turn_geometry(
         )
 
         if a_tf_turn_cable_space_no_void <= 0.0e0:
-            if t_conductor < 0.0e0:
+            if dx_tf_turn_conduit_full_average < 0.0e0:
                 logger.error(
                     "Negative cable space dimension. %s %s",
                     a_tf_turn_cable_space_no_void,
@@ -3317,7 +3331,9 @@ def tf_cable_in_conduit_averaged_turn_geometry(
                 a_tf_turn_cable_space_no_void = dx_tf_turn_cable_space_average**2
 
         # Cross-sectional area of conduit jacket per turn [m2]
-        a_tf_turn_steel = t_conductor**2 - a_tf_turn_cable_space_no_void
+        a_tf_turn_steel = (
+            dx_tf_turn_conduit_full_average**2 - a_tf_turn_cable_space_no_void
+        )
 
         return CICCAveragedTurnGeometry(
             a_tf_turn_cable_space_no_void=a_tf_turn_cable_space_no_void,
@@ -3328,7 +3344,7 @@ def tf_cable_in_conduit_averaged_turn_geometry(
             dx_tf_turn_general=dx_tf_turn_general,
             dr_tf_turn=dr_tf_turn,
             dx_tf_turn=dx_tf_turn,
-            t_conductor=t_conductor,
+            dx_tf_turn_conduit_full_average=dx_tf_turn_conduit_full_average,
             radius_tf_turn_cable_space_corners=radius_tf_turn_cable_space_corners,
             dx_tf_turn_cable_space_average=dx_tf_turn_cable_space_average,
             a_tf_turn_cable_space_effective=a_tf_turn_cable_space_effective,
@@ -3421,7 +3437,9 @@ def tf_cable_in_conduit_integer_turn_geometry(
         # Radial and toroidal dimension of conductor [m]
         t_conductor_radial = dr_tf_turn - 2.0e0 * dx_tf_turn_insulation
         t_conductor_toroidal = dx_tf_turn - 2.0e0 * dx_tf_turn_insulation
-        t_conductor = np.sqrt(t_conductor_radial * t_conductor_toroidal)
+        dx_tf_turn_conduit_full_average = np.sqrt(
+            t_conductor_radial * t_conductor_toroidal
+        )
 
         # Dimension of square cable space inside conduit [m]
         dr_tf_turn_cable_space = t_conductor_radial - 2.0e0 * dx_tf_turn_steel
@@ -3497,7 +3515,7 @@ def tf_cable_in_conduit_integer_turn_geometry(
             n_tf_coil_turns=n_tf_coil_turns,
             t_conductor_radial=t_conductor_radial,
             t_conductor_toroidal=t_conductor_toroidal,
-            t_conductor=t_conductor,
+            dx_tf_turn_conduit_full_average=dx_tf_turn_conduit_full_average,
             dr_tf_turn_cable_space=dr_tf_turn_cable_space,
             dx_tf_turn_cable_space=dx_tf_turn_cable_space,
             dx_tf_turn_cable_space_average=dx_tf_turn_cable_space_average,
@@ -3694,7 +3712,7 @@ class CROCOAveragedTurnGeometry:
     dx_tf_turn_general: float
     dr_tf_turn: float
     dx_tf_turn: float
-    t_conductor: float
+    dx_tf_turn_conduit_full_average: float
     dx_tf_turn_cable_space_average: float
 
 
@@ -3762,10 +3780,12 @@ def run(self, output: bool = False):
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
             self.data.tfcoil.c_tf_turn = avg_turn_geometry.c_tf_turn
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
-            d_sc_tf.dr_tf_turn = avg_turn_geometry.dr_tf_turn
-            d_sc_tf.dx_tf_turn = avg_turn_geometry.dx_tf_turn
-            self.data.tfcoil.t_conductor = avg_turn_geometry.t_conductor
-            d_sc_tf.dx_tf_turn_cable_space_average = (
+            self.data.superconducting_tfcoil.dr_tf_turn = avg_turn_geometry.dr_tf_turn
+            self.data.superconducting_tfcoil.dx_tf_turn = avg_turn_geometry.dx_tf_turn
+            self.data.tfcoil.dx_tf_turn_conduit_full_average = (
+                avg_turn_geometry.dx_tf_turn_conduit_full_average
+            )
+            self.data.superconducting_tfcoil.dx_tf_turn_cable_space_average = (
                 avg_turn_geometry.dx_tf_turn_cable_space_average
             )
 
@@ -3825,8 +3845,8 @@ def run(self, output: bool = False):
             / self.data.tfcoil.a_tf_inboard_total
         )
 
-        croco_cable_space_geometry = self.tf_turn_croco_cable_space_properties(
-            t_conductor=self.data.tfcoil.t_conductor,
+        croco_cable_space_geometry: CroCoCableSpaceGeometry = self.tf_turn_croco_cable_space_properties(
+            dx_tf_turn_conduit_full_average=self.data.tfcoil.dx_tf_turn_conduit_full_average,
             dx_tf_turn_steel=self.data.tfcoil.dx_tf_turn_steel,
         )
 
@@ -4315,7 +4335,7 @@ def tf_croco_averaged_turn_geometry(
         dr_tf_turn = dx_tf_turn_general
         dx_tf_turn = dx_tf_turn_general
 
-        t_conductor = (
+        dx_tf_turn_conduit_full_average = (
             -layer_ins + np.sqrt(layer_ins**2 + 4.0e00 * a_tf_turn)
         ) / 2 - 2.0e0 * dx_tf_turn_insulation
 
@@ -4323,13 +4343,21 @@ def tf_croco_averaged_turn_geometry(
         n_tf_coil_turns = a_tf_wp_no_insulation / a_tf_turn
 
         # Area of inter-turn insulation: single turn [m²]
-        a_tf_turn_insulation = a_tf_turn - t_conductor**2
+        a_tf_turn_insulation = a_tf_turn - dx_tf_turn_conduit_full_average**2
+
+        a_tf_turn_cable_space_no_void = copy.copy(
+            self.data.tfcoil.a_tf_turn_cable_space_no_void
+        )
 
         # Diameter of circular cable space inside conduit [m]
-        dx_tf_turn_cable_space_average = t_conductor - 2.0e0 * dx_tf_turn_steel
+        dx_tf_turn_cable_space_average = (
+            dx_tf_turn_conduit_full_average - 2.0e0 * dx_tf_turn_steel
+        )
 
         # Cross-sectional area of conduit jacket per turn [m²]
-        a_tf_turn_steel = t_conductor**2 - self.data.tfcoil.a_tf_turn_cable_space_no_void
+        a_tf_turn_steel = (
+            dx_tf_turn_conduit_full_average**2 - a_tf_turn_cable_space_no_void
+        )
 
         return CROCOAveragedTurnGeometry(
             a_tf_turn_cable_space_no_void=self.data.tfcoil.a_tf_turn_cable_space_no_void,
@@ -4340,7 +4368,7 @@ def tf_croco_averaged_turn_geometry(
             dx_tf_turn_general=dx_tf_turn_general,
             dr_tf_turn=dr_tf_turn,
             dx_tf_turn=dx_tf_turn,
-            t_conductor=t_conductor,
+            dx_tf_turn_conduit_full_average=dx_tf_turn_conduit_full_average,
             dx_tf_turn_cable_space_average=dx_tf_turn_cable_space_average,
         )
 
@@ -4535,25 +4563,43 @@ def tf_croco_superconductor_properties(
 
     @staticmethod
     def tf_turn_croco_cable_space_properties(
-        t_conductor: float, dx_tf_turn_steel: float
+        dx_tf_turn_conduit_full_average: float, dx_tf_turn_steel: float
     ) -> CroCoCableSpaceGeometry:
         """Calculate the properties of the cable space in the TF turn for a CroCo
         conductor.
 
         Parameters
         ----------
-        t_conductor : float
+        dx_tf_turn_conduit_full_average : float
             Thickness of the conductor in the TF turn (in meters).
         dx_tf_turn_steel : float
             Thickness of the steel layer in the TF turn (in meters).
 
         Returns
         -------
-        :
-            CroCo cable space geometry
+        
+        CroCoCableSpaceGeometry
+             A dataclass containing the calculated properties of the cable space in
+             the TF turn, including:
+            - dia_tf_turn_croco_cable: Diameter of the circular cable space in the TF
+              turn (in meters).
+            - a_tf_turn_cable_space_no_void: Area of the cable space in the TF turn
+              without voids (in square meters).
+            - a_tf_turn_cable_space_effective: Effective area of the cable space in
+              the TF turn after accounting for cooling channels and voids
+              (in square meters).
+            - a_tf_turn_steel: Area of the steel in the TF turn (in square meters).
+            - conductor_area: Total area of the conductor in the TF turn
+              (in square meters).
+            - conductor_jacket_area: Area of the conductor jacket in the TF turn
+              (in square meters).
+            - conductor_jacket_fraction: Fraction of the conductor area that is the
+              jacket (dimensionless).
+
+
         """
-        dia_tf_turn_croco_cable = t_conductor / 3.0e0 - dx_tf_turn_steel * (
-            2.0e0 / 3.0e0
+        dia_tf_turn_croco_cable = (
+            dx_tf_turn_conduit_full_average / 3.0e0 - dx_tf_turn_steel * (2.0e0 / 3.0e0)
         )
 
         # Area of the full cable circle in the turn
@@ -4566,7 +4612,9 @@ def tf_turn_croco_cable_space_properties(
             a_tf_turn_cable_space_no_void - 0.25e0 * np.pi * dia_tf_turn_croco_cable**2
         )
 
-        conductor_area = t_conductor**2  # does this not assume it's a sqaure???
+        conductor_area = (
+            dx_tf_turn_conduit_full_average**2
+        )  # does this not assume it's a sqaure???
 
         conductor_jacket_area = conductor_area - a_tf_turn_cable_space_no_void
         a_tf_turn_steel = conductor_jacket_area
@@ -4749,8 +4797,8 @@ def output_croco_info(self) -> None:
         po.ovarre(
             self.outfile,
             "Width of square conductor (cable + steel jacket) (m)",
-            "(t_conductor)",
-            self.data.tfcoil.t_conductor,
+            "(dx_tf_turn_conduit_full_average)",
+            self.data.tfcoil.dx_tf_turn_conduit_full_average,
             "OP ",
         )
         po.ovarre(
diff --git a/tests/unit/models/tfcoil/test_sctfcoil.py b/tests/unit/models/tfcoil/test_sctfcoil.py
index ca7a56e990..589de60809 100644
--- a/tests/unit/models/tfcoil/test_sctfcoil.py
+++ b/tests/unit/models/tfcoil/test_sctfcoil.py
@@ -988,7 +988,7 @@ class TfIntegerTurnGeomParam(NamedTuple):
 
     dx_tf_wp_insertion_gap: Any = None
 
-    t_conductor: Any = None
+    dx_tf_turn_conduit_full_average: Any = None
 
     dx_tf_turn_general: Any = None
 
@@ -1054,7 +1054,7 @@ class TfIntegerTurnGeomParam(NamedTuple):
             dr_tf_wp_with_insulation=0.54261087836601019,
             dx_tf_wp_insulation=0.0080000000000000019,
             dx_tf_wp_insertion_gap=0.01,
-            t_conductor=0,
+            dx_tf_turn_conduit_full_average=0,
             dx_tf_turn_general=0,
             c_tf_coil=14805350.287500001,
             dx_tf_wp_toroidal_min=1.299782604942499,
@@ -1088,7 +1088,7 @@ class TfIntegerTurnGeomParam(NamedTuple):
             dr_tf_wp_with_insulation=0.54261087836601019,
             dx_tf_wp_insulation=0.0080000000000000019,
             dx_tf_wp_insertion_gap=0.01,
-            t_conductor=0.052553108427885735,
+            dx_tf_turn_conduit_full_average=0.052553108427885735,
             dx_tf_turn_general=0.056579413904423038,
             c_tf_coil=14805350.287500001,
             dx_tf_wp_toroidal_min=1.299782604942499,
@@ -1154,7 +1154,7 @@ def test_tf_cable_in_conduit_integer_turn_geometry(
         0.75 * tfintegerturngeomparam.dx_tf_turn_steel
     )
 
-    assert integer_turn_geometry.t_conductor == pytest.approx(
+    assert integer_turn_geometry.dx_tf_turn_conduit_full_average == pytest.approx(
         tfintegerturngeomparam.expected_t_conductor
     )
 
@@ -1214,7 +1214,7 @@ def test_tf_cable_in_conduit_integer_turn_geometry(
 class TfAveragedTurnGeomParam(NamedTuple):
     layer_ins: Any = None
 
-    t_conductor: Any = None
+    dx_tf_turn_conduit_full_average: Any = None
 
     dx_tf_turn_general: Any = None
 
@@ -1264,7 +1264,7 @@ class TfAveragedTurnGeomParam(NamedTuple):
     [
         TfAveragedTurnGeomParam(
             layer_ins=0,
-            t_conductor=0,
+            dx_tf_turn_conduit_full_average=0,
             dx_tf_turn_general=0,
             i_dx_tf_turn_general_input=False,
             c_tf_turn=65000,
@@ -1289,7 +1289,7 @@ class TfAveragedTurnGeomParam(NamedTuple):
         ),
         TfAveragedTurnGeomParam(
             layer_ins=0,
-            t_conductor=0.047932469413859431,
+            dx_tf_turn_conduit_full_average=0.047932469413859431,
             dx_tf_turn_general=0.049532469413859428,
             i_dx_tf_turn_general_input=False,
             c_tf_turn=65000,
@@ -1314,7 +1314,7 @@ class TfAveragedTurnGeomParam(NamedTuple):
         ),
         TfAveragedTurnGeomParam(
             layer_ins=0,
-            t_conductor=5.712e-02,
+            dx_tf_turn_conduit_full_average=5.712e-02,
             dx_tf_turn_general=0.05872,
             i_dx_tf_turn_general_input=True,
             c_tf_turn=0,
@@ -1339,7 +1339,7 @@ class TfAveragedTurnGeomParam(NamedTuple):
         ),
         TfAveragedTurnGeomParam(
             layer_ins=0,
-            t_conductor=0.058296,
+            dx_tf_turn_conduit_full_average=0.058296,
             dx_tf_turn_general=0,
             i_dx_tf_turn_general_input=False,
             c_tf_turn=0,
@@ -1397,7 +1397,7 @@ def test_tf_cable_in_conduit_averaged_turn_geometry(
     )
 
     # Existing checks
-    assert avg_turn_geometry.t_conductor == pytest.approx(
+    assert avg_turn_geometry.dx_tf_turn_conduit_full_average == pytest.approx(
         tfaveragedturngeomparam.expected_t_conductor
     )
     assert avg_turn_geometry.dx_tf_turn_general == pytest.approx(

From f1578591e1239012a65e28f7ee4d1ff044834ad5 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 16:50:02 +0100
Subject: [PATCH 11/21] Refactor SuperconductingTFData and related tests to
 rename conductor dimensions for clarity

---
 .../superconducting_tf_coil_variables.py      |  8 ++--
 process/models/tfcoil/superconducting.py      | 39 ++++++++++---------
 tests/unit/models/tfcoil/test_sctfcoil.py     | 16 ++++----
 3 files changed, 33 insertions(+), 30 deletions(-)

diff --git a/process/data_structure/superconducting_tf_coil_variables.py b/process/data_structure/superconducting_tf_coil_variables.py
index ad69d229f3..cb9dbd5817 100644
--- a/process/data_structure/superconducting_tf_coil_variables.py
+++ b/process/data_structure/superconducting_tf_coil_variables.py
@@ -126,11 +126,11 @@ class SuperconductingTFData:
     tan_theta_coil: float = 0.0
     """Tan half toroidal angular extent of a single TF coil inboard leg"""
 
-    t_conductor_radial: float = 0.0
-    """Conductor area radial and toroidal dimension (integer turn only) [m]"""
+    dr_tf_turn_conduit_full: float = 0.0
+    """Radial thickness of the full conduit around the cable space (integer turn only) [m]"""
 
-    t_conductor_toroidal: float = 0.0
-    """Conductor area radial and toroidal dimension (integer turn only) [m]"""
+    dx_tf_turn_conduit_full_toroidal: float = 0.0
+    """Toroidal thickness of the full conduit around the cable space (integer turn only) [m]"""
 
     dr_tf_turn_cable_space: float = 0.0
     """Cable area radial and toroidal dimension (integer turn only) [m]"""
diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 9c7dc72273..9953e384d2 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -571,15 +571,15 @@ def output_general_superconducting_tf_info(self) -> None:
             po.ovarre(
                 self.outfile,
                 "Radial width of conductor (m)",
-                "(t_conductor_radial)",
-                d_sc_tf.t_conductor_radial,
+                "(dr_tf_turn_conduit_full)",
+                self.data.superconducting_tfcoil.dr_tf_turn_conduit_full,
                 "OP ",
             )
             po.ovarre(
                 self.outfile,
                 "Toroidal width of conductor (m)",
-                "(t_conductor_toroidal)",
-                d_sc_tf.t_conductor_toroidal,
+                "(dx_tf_turn_conduit_full_toroidal)",
+                self.data.superconducting_tfcoil.dx_tf_turn_conduit_full_toroidal,
                 "OP ",
             )
             po.ovarre(
@@ -2214,8 +2214,8 @@ class CICCIntegerTurnGeometry:
     a_tf_turn_insulation: float
     c_tf_turn: float
     n_tf_coil_turns: int
-    t_conductor_radial: float
-    t_conductor_toroidal: float
+    dr_tf_turn_conduit_full: float
+    dx_tf_turn_conduit_full_toroidal: float
     dx_tf_turn_conduit_full_average: float
     dr_tf_turn_cable_space: float
     dx_tf_turn_cable_space: float
@@ -2316,11 +2316,11 @@ def run(self, output: bool = False):
             )
             self.data.tfcoil.c_tf_turn = int_turn_geometry.c_tf_turn
             self.data.tfcoil.n_tf_coil_turns = int_turn_geometry.n_tf_coil_turns
-            self.data.superconducting_tfcoil.t_conductor_radial = (
-                int_turn_geometry.t_conductor_radial
+            self.data.superconducting_tfcoil.dr_tf_turn_conduit_full = (
+                int_turn_geometry.dr_tf_turn_conduit_full
             )
-            self.data.superconducting_tfcoil.t_conductor_toroidal = (
-                int_turn_geometry.t_conductor_toroidal
+            self.data.superconducting_tfcoil.dx_tf_turn_conduit_full_toroidal = (
+                int_turn_geometry.dx_tf_turn_conduit_full_toroidal
             )
             self.data.tfcoil.dx_tf_turn_conduit_full_average = (
                 int_turn_geometry.dx_tf_turn_conduit_full_average
@@ -3435,15 +3435,17 @@ def tf_cable_in_conduit_integer_turn_geometry(
         c_tf_turn = c_tf_coil / n_tf_coil_turns
 
         # Radial and toroidal dimension of conductor [m]
-        t_conductor_radial = dr_tf_turn - 2.0e0 * dx_tf_turn_insulation
-        t_conductor_toroidal = dx_tf_turn - 2.0e0 * dx_tf_turn_insulation
+        dr_tf_turn_conduit_full = dr_tf_turn - 2.0e0 * dx_tf_turn_insulation
+        dx_tf_turn_conduit_full_toroidal = dx_tf_turn - 2.0e0 * dx_tf_turn_insulation
         dx_tf_turn_conduit_full_average = np.sqrt(
-            t_conductor_radial * t_conductor_toroidal
+            dr_tf_turn_conduit_full * dx_tf_turn_conduit_full_toroidal
         )
 
         # Dimension of square cable space inside conduit [m]
-        dr_tf_turn_cable_space = t_conductor_radial - 2.0e0 * dx_tf_turn_steel
-        dx_tf_turn_cable_space = t_conductor_toroidal - 2.0e0 * dx_tf_turn_steel
+        dr_tf_turn_cable_space = dr_tf_turn_conduit_full - 2.0e0 * dx_tf_turn_steel
+        dx_tf_turn_cable_space = (
+            dx_tf_turn_conduit_full_toroidal - 2.0e0 * dx_tf_turn_steel
+        )
         dx_tf_turn_cable_space_average = np.sqrt(
             dr_tf_turn_cable_space * dx_tf_turn_cable_space
         )
@@ -3497,7 +3499,8 @@ def tf_cable_in_conduit_integer_turn_geometry(
 
         # Cross-sectional area of conduit jacket per turn [m²]
         a_tf_turn_steel = (
-            t_conductor_radial * t_conductor_toroidal - a_tf_turn_cable_space_no_void
+            dr_tf_turn_conduit_full * dx_tf_turn_conduit_full_toroidal
+            - a_tf_turn_cable_space_no_void
         )
 
         # Area of inter-turn insulation: single turn [m²]
@@ -3513,8 +3516,8 @@ def tf_cable_in_conduit_integer_turn_geometry(
             a_tf_turn_insulation=a_tf_turn_insulation,
             c_tf_turn=c_tf_turn,
             n_tf_coil_turns=n_tf_coil_turns,
-            t_conductor_radial=t_conductor_radial,
-            t_conductor_toroidal=t_conductor_toroidal,
+            dr_tf_turn_conduit_full=dr_tf_turn_conduit_full,
+            dx_tf_turn_conduit_full_toroidal=dx_tf_turn_conduit_full_toroidal,
             dx_tf_turn_conduit_full_average=dx_tf_turn_conduit_full_average,
             dr_tf_turn_cable_space=dr_tf_turn_cable_space,
             dx_tf_turn_cable_space=dx_tf_turn_cable_space,
diff --git a/tests/unit/models/tfcoil/test_sctfcoil.py b/tests/unit/models/tfcoil/test_sctfcoil.py
index 589de60809..8f1be0cc3a 100644
--- a/tests/unit/models/tfcoil/test_sctfcoil.py
+++ b/tests/unit/models/tfcoil/test_sctfcoil.py
@@ -996,9 +996,9 @@ class TfIntegerTurnGeomParam(NamedTuple):
 
     dx_tf_wp_toroidal_min: Any = None
 
-    t_conductor_radial: Any = None
+    dr_tf_turn_conduit_full: Any = None
 
-    t_conductor_toroidal: Any = None
+    dx_tf_turn_conduit_full_toroidal: Any = None
 
     dr_tf_turn_cable_space: Any = None
 
@@ -1058,8 +1058,8 @@ class TfIntegerTurnGeomParam(NamedTuple):
             dx_tf_turn_general=0,
             c_tf_coil=14805350.287500001,
             dx_tf_wp_toroidal_min=1.299782604942499,
-            t_conductor_radial=0,
-            t_conductor_toroidal=0,
+            dr_tf_turn_conduit_full=0,
+            dx_tf_turn_conduit_full_toroidal=0,
             dr_tf_turn_cable_space=0,
             dx_tf_turn_cable_space=0,
             dr_tf_turn=0,
@@ -1092,8 +1092,8 @@ class TfIntegerTurnGeomParam(NamedTuple):
             dx_tf_turn_general=0.056579413904423038,
             c_tf_coil=14805350.287500001,
             dx_tf_wp_toroidal_min=1.299782604942499,
-            t_conductor_radial=0.046661087836601015,
-            t_conductor_toroidal=0.059189130247124938,
+            dr_tf_turn_conduit_full=0.046661087836601015,
+            dx_tf_turn_conduit_full_toroidal=0.059189130247124938,
             dr_tf_turn_cable_space=0.030661087836601014,
             dx_tf_turn_cable_space=0.043189130247124938,
             dr_tf_turn=0.050661087836601018,
@@ -1162,11 +1162,11 @@ def test_tf_cable_in_conduit_integer_turn_geometry(
         tfintegerturngeomparam.expected_dx_tf_turn_general
     )
 
-    assert integer_turn_geometry.t_conductor_radial == pytest.approx(
+    assert integer_turn_geometry.dr_tf_turn_conduit_full == pytest.approx(
         tfintegerturngeomparam.expected_t_conductor_radial
     )
 
-    assert integer_turn_geometry.t_conductor_toroidal == pytest.approx(
+    assert integer_turn_geometry.dx_tf_turn_conduit_full_toroidal == pytest.approx(
         tfintegerturngeomparam.expected_t_conductor_toroidal
     )
 

From 78d4af5314e0448ace2f6aa0a404bb1ff417c805 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Fri, 12 Jun 2026 17:10:18 +0100
Subject: [PATCH 12/21] Refactor TFData and SuperconductingTFCoil to clarify
 mass calculations and improve variable naming

---
 process/data_structure/tfcoil_variables.py |  5 ++-
 process/models/tfcoil/superconducting.py   | 49 +++++-----------------
 2 files changed, 15 insertions(+), 39 deletions(-)

diff --git a/process/data_structure/tfcoil_variables.py b/process/data_structure/tfcoil_variables.py
index 9091b3f6fb..9cec919c1b 100644
--- a/process/data_structure/tfcoil_variables.py
+++ b/process/data_structure/tfcoil_variables.py
@@ -757,7 +757,10 @@ class TFData:
     """mass of ground-wall insulation layer per coil (kg/coil)"""
 
     m_tf_coils_total: float = 0.0
-    """total mass of the TF coils (kg)"""
+    """Total mass of all TF coils (kg)"""
+
+    m_tf_coil: float = 0.0
+    """Total mass of one TF coil (kg)"""
 
     dx_tf_wp_primary_toroidal: float = 0.0
     """width of first step of winding pack (m)"""
diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 9953e384d2..95544fc560 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -709,8 +709,8 @@ def output_general_superconducting_tf_info(self) -> None:
         po.ovarre(
             self.outfile,
             "Mass of each TF coil (kg)",
-            "(m_tf_coils_total/n_tf_coils)",
-            self.data.tfcoil.m_tf_coils_total / self.data.tfcoil.n_tf_coils,
+            "(m_tf_coil)",
+            self.data.tfcoil.m_tf_coil,
             "OP ",
         )
         po.ovarre(
@@ -1986,11 +1986,16 @@ def superconducting_tf_coil_areas_and_masses(self):
         # ---------------------------------
 
         # Total TF coil mass [kg] (all coils)
-        self.data.tfcoil.m_tf_coils_total = (
+        self.data.tfcoil.m_tf_coil = (
             self.data.tfcoil.m_tf_coil_case
             + self.data.tfcoil.m_tf_coil_conductor
             + self.data.tfcoil.m_tf_coil_wp_insulation
-        ) * self.data.tfcoil.n_tf_coils
+        )
+
+        # Total TF coil mass [kg] (all coils)
+        self.data.tfcoil.m_tf_coils_total = (
+            self.data.tfcoil.m_tf_coil * self.data.tfcoil.n_tf_coils
+        )
 
         # If spherical tokamak, distribute between centrepost and outboard legs
         # (in this case, total TF coil length = inboard `cplen` +
@@ -3630,48 +3635,16 @@ def output_cable_in_conduit_cable_info(self) -> None:
 
         po.ovarre(
             self.outfile,
-            "Copper fraction of conductor",
+            "Copper area fraction of cable conductor",
             "(f_a_tf_turn_cable_copper)",
             self.data.tfcoil.f_a_tf_turn_cable_copper,
         )
         po.ovarre(
             self.outfile,
-            "Superconductor fraction of conductor",
+            "Superconductor area fraction of cable conductor",
             "(1-f_a_tf_turn_cable_copper)",
             1 - self.data.tfcoil.f_a_tf_turn_cable_copper,
         )
-        ap = (
-            self.data.tfcoil.a_tf_wp_conductor
-            + self.data.tfcoil.n_tf_coil_turns * self.data.tfcoil.a_tf_turn_steel
-            + self.data.tfcoil.a_tf_coil_wp_turn_insulation
-            + self.data.tfcoil.a_tf_wp_extra_void
-            + self.data.tfcoil.a_tf_wp_coolant_channels
-        )
-        po.ovarre(
-            self.outfile,
-            "Check total area fractions in winding pack = 1",
-            "",
-            (
-                self.data.tfcoil.a_tf_wp_conductor
-                + self.data.tfcoil.n_tf_coil_turns * self.data.tfcoil.a_tf_turn_steel
-                + self.data.tfcoil.a_tf_coil_wp_turn_insulation
-                + self.data.tfcoil.a_tf_wp_extra_void
-                + self.data.tfcoil.a_tf_wp_coolant_channels
-            )
-            / ap,
-        )
-        po.ovarre(
-            self.outfile,
-            "minimum TF conductor temperature margin  (K)",
-            "(temp_tf_superconductor_margin_min)",
-            self.data.tfcoil.temp_tf_superconductor_margin_min,
-        )
-        po.ovarre(
-            self.outfile,
-            "TF conductor temperature margin (K)",
-            "(temp_tf_superconductor_margin)",
-            self.data.tfcoil.temp_tf_superconductor_margin,
-        )
 
         po.ovarre(
             self.outfile,

From df3a01b270c552e3753b82a7483ce7c1efef79e0 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Mon, 15 Jun 2026 13:21:08 +0100
Subject: [PATCH 13/21] Update tests for ST to use croco turn type for tapes

---
 process/models/tfcoil/superconducting.py               | 10 ----------
 .../input_files/spherical_tokamak_eval.IN.DAT          |  1 +
 tests/regression/input_files/st_regression.IN.DAT      |  5 ++++-
 3 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 95544fc560..08d88b4b8f 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -3944,7 +3944,6 @@ def run(self, output: bool = False):
             b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
             cur_tf_turn=self.data.tfcoil.c_tf_turn,
             temp_tf_peak=self.data.tfcoil.tftmp,
-            a_tf_turn_cable_space_effective=self.data.superconducting_tfcoil.a_tf_turn_cable_space_effective,
             i_tf_superconductor=self.data.tfcoil.i_tf_sc_mat,
             dr_tf_hts_tape=self.data.superconducting_tfcoil.dr_tf_hts_tape,
             dx_tf_hts_tape_rebco=self.data.superconducting_tfcoil.dx_tf_hts_tape_rebco,
@@ -4354,7 +4353,6 @@ def tf_croco_superconductor_properties(
         b_tf_inboard_peak: float,
         cur_tf_turn: float,
         temp_tf_peak: float,
-        a_tf_turn_cable_space_effective: float,
         i_tf_superconductor: int,
         dr_tf_hts_tape: float,
         dx_tf_hts_tape_rebco: float,
@@ -4411,8 +4409,6 @@ def tf_croco_superconductor_properties(
         else:
             strain = self.data.tfcoil.str_wp
 
-        f_a_tf_turn_tape_superconductor = dx_tf_hts_tape_rebco / dx_tf_hts_tape_total
-
         # =================================================================
 
         if i_tf_superconductor == SuperconductorModel.CROCO_REBCO:
@@ -4474,12 +4470,6 @@ def tf_croco_superconductor_properties(
 
         # =================================================================
 
-        # Scale for the copper area fraction of the cable
-        j_tape_critical = j_superconductor_critical * f_a_tf_turn_tape_superconductor
-
-        #  Critical current in turn all turn cables
-        c_turn_cables_critical = j_tape_critical * a_tf_turn_cable_space_effective
-
         # Strand critical current calulation for costing in $ / kAm
         # Already includes buffer and support layers so no need to include
         # f_a_tf_turn_cable_copper here
diff --git a/tests/regression/input_files/spherical_tokamak_eval.IN.DAT b/tests/regression/input_files/spherical_tokamak_eval.IN.DAT
index e2b04aa2e9..29ab2a1bae 100644
--- a/tests/regression/input_files/spherical_tokamak_eval.IN.DAT
+++ b/tests/regression/input_files/spherical_tokamak_eval.IN.DAT
@@ -69,6 +69,7 @@ gapomin  = 0.0 * minimum gap between outboard vacuum vessel and TF coil (m) (`it
 iohcl    = 0 * Switch for existence of central solenoid;
 i_cs_precomp = 0 * Switch for existence of central solenoid pre-compression structure;
 i_tf_inside_cs = 0 * Switch for placing the TF coil inside the CS
+i_tf_turn_type = 2 * CroCo Turn geometry for HTS Tapes
 dr_cs    = 0.20016400484967947 * Central solenoid thickness (m) (`iteration variable 16`)
 i_r_cp_top = 2 * Switch selecting the he parametrization of the outer radius of the top of the CP part of the TF coil
 dr_fw_plasma_gap_inboard  = 0.1 * Gap between plasma and first wall; inboard side (m) (if `i_plasma_wall_gap=1`)
diff --git a/tests/regression/input_files/st_regression.IN.DAT b/tests/regression/input_files/st_regression.IN.DAT
index 78f4028107..37f34ed113 100644
--- a/tests/regression/input_files/st_regression.IN.DAT
+++ b/tests/regression/input_files/st_regression.IN.DAT
@@ -789,7 +789,10 @@ p_plasma_separatrix_rmajor_max_mw = 40.0
 
 n_tf_coils = 12 
 * DESCRIPTION:   Number of TF Coils 
-* JUSTIFICATION: 
+* JUSTIFICATION:
+
+i_tf_turn_type = 2
+* CroCo Turn geometry for HTS Tapes
 
 i_tf_shape = 2
 * DESCRIPTION:   Switch for TF coil toroidal shape (2: Picture frame coils)

From a5f6d004d24ed49a0f7d8d4c6806b13956f584a9 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Mon, 15 Jun 2026 13:34:03 +0100
Subject: [PATCH 14/21] Add strain calculation and superconductor temperature
 margin logic in CROCOSuperconductingTFCoil

---
 process/models/tfcoil/superconducting.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 08d88b4b8f..df0a7f3b10 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -3973,6 +3973,23 @@ def run(self, output: bool = False):
             superconductor_critical_properties.c_turn_cables_critical
         )
 
+        if self.data.tfcoil.i_str_wp == 0:
+            strain = self.data.tfcoil.str_tf_con_res
+        else:
+            strain = self.data.tfcoil.str_wp
+
+        self.data.tfcoil.temp_tf_superconductor_margin = self.calculate_superconductor_temperature_margin(
+            i_tf_superconductor=self.data.tfcoil.i_tf_sc_mat,
+            j_superconductor=self.data.superconducting_tfcoil.j_tf_superconductor,
+            b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
+            strain=strain,
+            bc20m=self.data.superconducting_tfcoil.b_tf_superconductor_critical_zero_temp_strain,
+            tc0m=self.data.superconducting_tfcoil.temp_tf_superconductor_critical_zero_field_strain,
+            c0=1.0e10,
+            temp_tf_coolant_peak_field=self.data.tfcoil.tftmp,
+            data=self.data,
+        )
+
         self.data.tfcoil.v_tf_coil_dump_quench_kv = (
             self.croco_voltage() / 1.0e3
         )  # TFC Quench voltage in kV

From 4fe38e1255cbde92df44714377bd43661126e8ba Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Mon, 15 Jun 2026 14:17:14 +0100
Subject: [PATCH 15/21] Add mapping for obsolete variable 't_conductor' to
 'dx_tf_turn_conduit_full_average'

---
 process/core/io/obsolete_vars.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/process/core/io/obsolete_vars.py b/process/core/io/obsolete_vars.py
index 7877a6bb48..e096c85032 100644
--- a/process/core/io/obsolete_vars.py
+++ b/process/core/io/obsolete_vars.py
@@ -473,6 +473,7 @@
     "i_cs_stress": None,
     "f_nd_alpha_electron": "f_nd_alpha_thermal_electron",
     "cost_model": "i_cost_model",
+    "t_conductor": "dx_tf_turn_conduit_full_average",
 }
 
 OBS_VARS_HELP = {

From 8a9bd72234a8b7708153af8973ecd1fec3eac008 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Mon, 15 Jun 2026 14:21:52 +0100
Subject: [PATCH 16/21] Remove outdated comments regarding critical current
 density in CICCSuperconductingTFCoil class

---
 process/models/tfcoil/superconducting.py | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index df0a7f3b10..e595e8ad2f 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -2809,13 +2809,6 @@ def tf_cable_in_conduit_superconductor_properties(
         and also the protection information (for a quench).
         Not used for the CroCo conductor.
 
-        The critical current density for a superconductor
-        (``j_superconductor_critical``) is for the superconducting strands/tape,
-        not including copper. The critical current density for
-        a cable (``j_crit_cable``) accounts for both the fraction of the cable taken
-        up by helium coolant channels, and the cable conductor copper fraction
-        (i.e., the copper in the superconducting strands and any additional copper,
-        such as REBCO tape support).
         """
         if (
             SuperconductorModel(i_tf_superconductor).sc_shape

From 5a7bce8e779a58ce5b482d89845084be1c76d8a3 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Mon, 15 Jun 2026 18:31:36 +0100
Subject: [PATCH 17/21] Refactor code structure for improved readability and
 maintainability

---
 process/core/input.py                         |   4 +-
 .../superconducting_tf_coil_variables.py      |  19 +-
 process/models/tfcoil/superconducting.py      | 219 +++++-------------
 3 files changed, 66 insertions(+), 176 deletions(-)

diff --git a/process/core/input.py b/process/core/input.py
index 1d7c132b6a..8f5d7512c4 100644
--- a/process/core/input.py
+++ b/process/core/input.py
@@ -297,7 +297,9 @@ def bounds(self) -> tuple[NumberType | None, NumberType | None]:
     "crane_arm_h": InputVariable("buildings", float, range=(1.0, 100.0)),
     "crane_clrnc_h": InputVariable("buildings", float, range=(0.0, 10.0)),
     "crane_clrnc_v": InputVariable("buildings", float, range=(0.0, 10.0)),
-    "dx_tf_croco_strand_copper": InputVariable("rebco", float, range=(0.001, 0.1)),
+    "dx_tf_croco_strand_copper": InputVariable(
+        "superconducting_tfcoil", float, range=(0.001, 0.1)
+    ),
     "cryomag_h": InputVariable("buildings", float, range=(1.0, 100.0)),
     "cryomag_l": InputVariable("buildings", float, range=(10.0, 1000.0)),
     "cryomag_w": InputVariable("buildings", float, range=(10.0, 1000.0)),
diff --git a/process/data_structure/superconducting_tf_coil_variables.py b/process/data_structure/superconducting_tf_coil_variables.py
index cb9dbd5817..f46559a045 100644
--- a/process/data_structure/superconducting_tf_coil_variables.py
+++ b/process/data_structure/superconducting_tf_coil_variables.py
@@ -267,33 +267,20 @@ class SuperconductingTFData:
     outer tube and central copper) (m²)"""
 
     a_tf_turn_copper_total: float = 0.0
-    """Area of all copper in the TF turn (m²)"""
+    """Area of all copper in the TF turn [m²]"""
 
     f_a_tf_turn_copper: float = 0.0
-    """Fraction of the TF turn area that is copper (m²)"""
+    """Fraction of the TF turn area that is copper"""
 
     a_tf_turn_croco_copper_bar: float = 0.0
     """Area of the central copper strand in the CroCo TF turn [m²]"""
 
     f_a_tf_turn_superconductor: float = 0.0
-    """Fraction of the TF turn area that is superconducting material [m²]"""
+    """Fraction of the TF turn area that is superconducting material"""
 
     a_tf_turn_croco_hastelloy: float = 0.0
     """Area of the Hastelloy in the CroCo cable space of the TF turn (includes tapes and outer tube) (m²)"""
 
-    conductor_hastelloy_fraction: float = 0.0
-    conductor_helium_area: float = 0.0
-    conductor_helium_fraction: float = 0.0
-    conductor_solder_area: float = 0.0
-    conductor_solder_fraction: float = 0.0
-    conductor_jacket_area: float = 0.0
-    conductor_jacket_fraction: float = 0.0
-    conductor_rebco_area: float = 0.0
-    conductor_rebco_fraction: float = 0.0
-    conductor_critical_current: float = 0.0
-    conductor_area: float = 0.0
-    """Area of cable space inside jacket"""
-
     t1: float = 0.0
 
     time2: float = 0.0
diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index e595e8ad2f..6735b003a4 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -81,7 +81,7 @@ def full_name(self):
         return self.name.title().replace("_", " ")
 
 
-@dataclass
+@dataclass(slots=True)
 class TFWPGeometry:
     """Data class for storing the geometry of the TF coil winding pack and
     ground insulation.
@@ -111,7 +111,7 @@ class TFWPGeometry:
     """WP ground insulation cross-sectional area [m²]"""
 
 
-@dataclass
+@dataclass(slots=True)
 class TFSuperconductorLimits:
     """Dataclass holding superconducting TF coil limits"""
 
@@ -641,12 +641,33 @@ def output_general_superconducting_tf_info(self) -> None:
             "(dx_tf_turn_insulation)",
             self.data.tfcoil.dx_tf_turn_insulation,
         )
+        po.oblnkl(self.outfile)
         po.ovarre(
             self.outfile,
             "TF coil turn area (m²)",
             "(a_tf_turn)",
             self.data.tfcoil.a_tf_turn,
         )
+        po.ovarre(
+            self.outfile,
+            "Total area of available cable space [m²]",
+            "(a_tf_turn_cable_space_no_void)",
+            self.data.tfcoil.a_tf_turn_cable_space_no_void,
+            "OP ",
+        )
+        po.ovarre(
+            self.outfile,
+            "True area of turn cable space usable by conductor [m²]",
+            "(a_tf_turn_cable_space_effective)",
+            self.data.superconducting_tfcoil.a_tf_turn_cable_space_effective,
+        )
+
+        po.ovarre(
+            self.outfile,
+            "Extra coolant area fraction in turn cable space",
+            "(f_a_tf_turn_cable_space_extra_void)",
+            self.data.tfcoil.f_a_tf_turn_cable_space_extra_void,
+        )
 
         po.oblnkl(self.outfile)
         po.ocmmnt(self.outfile, "----------------------------")
@@ -2188,9 +2209,9 @@ def run_and_output_stress(self) -> None:
                 self.data.tfcoil.sig_tf_wp = 0.0e0
 
 
-@dataclass
-class CICCAveragedTurnGeometry:
-    """Averaged turn geometry for a CICC conductor with LTS cables."""
+@dataclass(slots=True)
+class TFGeneralTurnGeometry:
+    """General turn geometry info needed for all TF turn types."""
 
     a_tf_turn_cable_space_no_void: float
     a_tf_turn_steel: float
@@ -2201,30 +2222,29 @@ class CICCAveragedTurnGeometry:
     dr_tf_turn: float
     dx_tf_turn: float
     dx_tf_turn_conduit_full_average: float
-    radius_tf_turn_cable_space_corners: float
     dx_tf_turn_cable_space_average: float
+
+
+@dataclass(slots=True)
+class CICCAveragedTurnGeometry(TFGeneralTurnGeometry):
+    """Averaged turn geometry for a CICC conductor with LTS cables."""
+
+    radius_tf_turn_cable_space_corners: float
     a_tf_turn_cable_space_effective: float
     f_a_tf_turn_cable_space_cooling: float
 
 
-@dataclass
-class CICCIntegerTurnGeometry:
+@dataclass(slots=True)
+class CICCIntegerTurnGeometry(TFGeneralTurnGeometry):
     """Integer turn geometry for a CICC conductor with LTS cables."""
 
     radius_tf_turn_cable_space_corners: float
-    dr_tf_turn: float
-    dx_tf_turn: float
-    a_tf_turn_cable_space_no_void: float
-    a_tf_turn_steel: float
-    a_tf_turn_insulation: float
-    c_tf_turn: float
-    n_tf_coil_turns: int
     dr_tf_turn_conduit_full: float
     dx_tf_turn_conduit_full_toroidal: float
-    dx_tf_turn_conduit_full_average: float
     dr_tf_turn_cable_space: float
     dx_tf_turn_cable_space: float
-    dx_tf_turn_cable_space_average: float
+    a_tf_turn_cable_space_effective: float
+    f_a_tf_turn_cable_space_cooling: float
 
 
 class CICCSuperconductingTFCoil(SuperconductingTFCoil):
@@ -3562,26 +3582,8 @@ def output_cable_in_conduit_cable_info(self) -> None:
             "(len_tf_superconductor_total)",
             d_sc_tf.len_tf_superconductor_total,
         )
-        po.ocmmnt(self.outfile, "Fractions by area")
-        po.ovarre(
-            self.outfile,
-            "internal area of the cable space",
-            "(a_tf_turn_cable_space_no_void)",
-            self.data.tfcoil.a_tf_turn_cable_space_no_void,
-        )
-        po.ovarre(
-            self.outfile,
-            "True area of turn cable space with gaps and channels removed",
-            "(a_tf_turn_cable_space_effective)",
-            d_sc_tf.a_tf_turn_cable_space_effective,
-        )
+        po.oblnkl(self.outfile)
 
-        po.ovarre(
-            self.outfile,
-            "Coolant fraction in conductor excluding central channel",
-            "(f_a_tf_turn_cable_space_extra_void)",
-            self.data.tfcoil.f_a_tf_turn_cable_space_extra_void,
-        )
         po.ovarre(
             self.outfile,
             "Area of steel in turn",
@@ -3669,33 +3671,20 @@ def output_cable_in_conduit_cable_info(self) -> None:
         )
 
 
-@dataclass
-class CROCOAveragedTurnGeometry:
-    """Dataclass holding CroCo averaged turn geometry parameters"""
-
-    a_tf_turn_cable_space_no_void: float
-    a_tf_turn_steel: float
-    a_tf_turn_insulation: float
-    n_tf_coil_turns: int
-    c_tf_turn: float
-    dx_tf_turn_general: float
-    dr_tf_turn: float
-    dx_tf_turn: float
-    dx_tf_turn_conduit_full_average: float
-    dx_tf_turn_cable_space_average: float
+@dataclass(slots=True)
+class CROCOAveragedTurnGeometry(TFGeneralTurnGeometry):
+    """Data class for the averaged turn geometry of a CroCo conductor."""
 
 
-@dataclass
+@dataclass(slots=True)
 class CroCoCableSpaceGeometry:
-    """Dataclass holding CroCo cable space geometry parameters"""
+    """Data class for the geometry of the cable space in a CroCo conductor."""
 
     dia_tf_turn_croco_cable: float
     a_tf_turn_cable_space_no_void: float
     a_tf_turn_cable_space_effective: float
     a_tf_turn_steel: float
-    conductor_area: float
-    conductor_jacket_area: float
-    conductor_jacket_fraction: float
+    f_a_tf_turn_cable_space_cooling: float
 
 
 class CROCOSuperconductingTFCoil(SuperconductingTFCoil):
@@ -3772,6 +3761,8 @@ def run(self, output: bool = False):
         # No central channel in CroCo conductor,
         self.data.tfcoil.a_tf_wp_coolant_channels = 0.0
 
+        self.data.tfcoil.f_a_tf_turn_cable_space_extra_void = 0.0
+
         # Void area in conductor for He, not including central channel [m²]
         self.data.tfcoil.a_tf_wp_extra_void = (
             self.data.tfcoil.a_tf_turn_cable_space_no_void
@@ -3829,10 +3820,8 @@ def run(self, output: bool = False):
             croco_cable_space_geometry.a_tf_turn_cable_space_effective
         )
         self.data.tfcoil.a_tf_turn_steel = croco_cable_space_geometry.a_tf_turn_steel
-        d_sc_tf.conductor_area = croco_cable_space_geometry.conductor_area
-        d_sc_tf.conductor_jacket_area = croco_cable_space_geometry.conductor_jacket_area
-        d_sc_tf.conductor_jacket_fraction = (
-            croco_cable_space_geometry.conductor_jacket_fraction
+        self.data.superconducting_tfcoil.f_a_tf_turn_cable_space_cooling = (
+            croco_cable_space_geometry.f_a_tf_turn_cable_space_cooling
         )
 
         croco_cable_geometry = calculate_croco_cable_geometry(
@@ -3906,24 +3895,6 @@ def run(self, output: bool = False):
         d_sc_tf.a_tf_turn_croco_hastelloy = (
             d_sc_tf.a_tf_croco_strand_hastelloy * N_CROCO_STRANDS_TURN
         )
-        d_sc_tf.conductor_hastelloy_fraction = (
-            d_sc_tf.a_tf_turn_croco_hastelloy / d_sc_tf.conductor_area
-        )
-
-        d_sc_tf.conductor_solder_area = (
-            d_sc_tf.a_tf_croco_strand_solder * N_CROCO_STRANDS_TURN
-        )
-        d_sc_tf.conductor_solder_fraction = (
-            d_sc_tf.conductor_solder_area / d_sc_tf.conductor_area
-        )
-
-        d_sc_tf.conductor_rebco_area = (
-            d_sc_tf.a_tf_croco_strand_rebco * N_CROCO_STRANDS_TURN
-        )
-        self.data.superconducting_tfcoil.f_a_tf_turn_superconductor = (
-            self.data.superconducting_tfcoil.conductor_rebco_area
-            / self.data.superconducting_tfcoil.conductor_area
-        )
 
         # Cross-sectional area per turn
         self.data.tfcoil.a_tf_turn = self.data.tfcoil.c_tf_total / (
@@ -4494,20 +4465,14 @@ def tf_croco_superconductor_properties(
         cur_tf_turn_croco_strand_critical = j_superconductor_critical * a_tf_croco_strand
 
         # Conductor properties
-        self.data.superconducting_tfcoil.conductor_critical_current = (
-            cur_tf_turn_croco_strand_critical * N_CROCO_STRANDS_TURN
-        )
-
-        d_sc_tf.tf_coppera_m2 = cur_tf_turn / d_sc_tf.a_tf_turn_croco_cable_space_copper
-
-        cur_critical = d_sc_tf.conductor_critical_current
+        cur_tf_turn_critical = cur_tf_turn_croco_strand_critical * N_CROCO_STRANDS_TURN
 
         # Critical current density in winding pack
         # a_tf_turn : Area per turn (i.e. entire jacketed conductor with insulation) (m2)
-        j_tf_wp_critical = cur_critical / a_tf_turn
+        j_tf_wp_critical = cur_tf_turn_critical / a_tf_turn
 
         #  Ratio of operating / critical current
-        f_c_tf_turn_operating_critical = cur_tf_turn / cur_critical
+        f_c_tf_turn_operating_critical = cur_tf_turn / cur_tf_turn_critical
 
         #  Operating current density
         j_tf_coil_turn = cur_tf_turn / a_tf_turn
@@ -4553,26 +4518,7 @@ def tf_turn_croco_cable_space_properties(
 
         Returns
         -------
-        
         CroCoCableSpaceGeometry
-             A dataclass containing the calculated properties of the cable space in
-             the TF turn, including:
-            - dia_tf_turn_croco_cable: Diameter of the circular cable space in the TF
-              turn (in meters).
-            - a_tf_turn_cable_space_no_void: Area of the cable space in the TF turn
-              without voids (in square meters).
-            - a_tf_turn_cable_space_effective: Effective area of the cable space in
-              the TF turn after accounting for cooling channels and voids
-              (in square meters).
-            - a_tf_turn_steel: Area of the steel in the TF turn (in square meters).
-            - conductor_area: Total area of the conductor in the TF turn
-              (in square meters).
-            - conductor_jacket_area: Area of the conductor jacket in the TF turn
-              (in square meters).
-            - conductor_jacket_fraction: Fraction of the conductor area that is the
-              jacket (dimensionless).
-
-
         """
         dia_tf_turn_croco_cable = (
             dx_tf_turn_conduit_full_average / 3.0e0 - dx_tf_turn_steel * (2.0e0 / 3.0e0)
@@ -4583,28 +4529,25 @@ def tf_turn_croco_cable_space_properties(
             9.0e0 / 4.0e0 * np.pi * dia_tf_turn_croco_cable**2
         )
 
-        # Area of the full cable spac circle minus the central copper strand
+        # Just the area of the CroCo strands in the turn (i.e. not including voids)
         a_tf_turn_cable_space_effective = (
-            a_tf_turn_cable_space_no_void - 0.25e0 * np.pi * dia_tf_turn_croco_cable**2
+            N_CROCO_STRANDS_TURN * np.pi * (dia_tf_turn_croco_cable / 2.0e0) ** 2
         )
 
-        conductor_area = (
-            dx_tf_turn_conduit_full_average**2
-        )  # does this not assume it's a sqaure???
-
-        conductor_jacket_area = conductor_area - a_tf_turn_cable_space_no_void
-        a_tf_turn_steel = conductor_jacket_area
+        a_tf_turn_steel = (
+            dx_tf_turn_conduit_full_average**2 - a_tf_turn_cable_space_no_void
+        )
 
-        conductor_jacket_fraction = conductor_jacket_area / conductor_area
+        f_a_tf_turn_cable_space_cooling = a_tf_turn_cable_space_no_void - (
+            (N_CROCO_STRANDS_TURN + 1) * np.pi * (dia_tf_turn_croco_cable / 2.0e0) ** 2
+        )
 
         return CroCoCableSpaceGeometry(
             dia_tf_turn_croco_cable=dia_tf_turn_croco_cable,
             a_tf_turn_cable_space_no_void=a_tf_turn_cable_space_no_void,
             a_tf_turn_cable_space_effective=a_tf_turn_cable_space_effective,
             a_tf_turn_steel=a_tf_turn_steel,
-            conductor_area=conductor_area,
-            conductor_jacket_area=conductor_jacket_area,
-            conductor_jacket_fraction=conductor_jacket_fraction,
+            f_a_tf_turn_cable_space_cooling=f_a_tf_turn_cable_space_cooling,
         )
 
     def croco_voltage(self) -> float:
@@ -4757,13 +4700,6 @@ def output_croco_info(self) -> None:
             "",
             N_CROCO_STRANDS_TURN,
         )
-        po.ovarre(
-            self.outfile,
-            "Total area of circular cable space (m²)",
-            "(a_tf_turn_cable_space_no_void)",
-            self.data.tfcoil.a_tf_turn_cable_space_no_void,
-            "OP ",
-        )
 
         po.oblnkl(self.outfile)
         po.ocmmnt(
@@ -4777,20 +4713,6 @@ def output_croco_info(self) -> None:
             self.data.tfcoil.dx_tf_turn_conduit_full_average,
             "OP ",
         )
-        po.ovarre(
-            self.outfile,
-            "Area of conductor (m²)",
-            "(conductor_area)",
-            self.data.superconducting_tfcoil.conductor_area,
-            "OP ",
-        )
-        po.ovarre(
-            self.outfile,
-            "REBCO area of conductor (m²)",
-            "(a_tf_croco_strand_rebco)",
-            d_sc_tf.conductor_rebco_area,
-            "OP ",
-        )
         po.ovarre(
             self.outfile,
             "Area of central copper bar (m²)",
@@ -4812,20 +4734,6 @@ def output_croco_info(self) -> None:
             self.data.superconducting_tfcoil.a_tf_turn_croco_hastelloy,
             "OP ",
         )
-        po.ovarre(
-            self.outfile,
-            "Solder area of conductor (m²)",
-            "(a_tf_croco_strand_solder)",
-            d_sc_tf.conductor_solder_area,
-            "OP ",
-        )
-        po.ovarre(
-            self.outfile,
-            "Jacket area of conductor (m²)",
-            "(jacket_area)",
-            d_sc_tf.conductor_jacket_area,
-            "OP ",
-        )
 
         po.ovarre(
             self.outfile,
@@ -4834,13 +4742,6 @@ def output_croco_info(self) -> None:
             d_sc_tf.cur_tf_turn_croco_strand_critical,
             "OP ",
         )
-        po.ovarre(
-            self.outfile,
-            "Critical current of conductor (A) ",
-            "(conductor_critical_current)",
-            d_sc_tf.conductor_critical_current,
-            "OP ",
-        )
 
 
 @staticmethod

From 30d2981a4a80d9c35eacc950ae0107d614470cd8 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Tue, 16 Jun 2026 10:30:48 +0100
Subject: [PATCH 18/21] Enhance CICC and CroCo TF coil area calculations and
 add new data structure for area fractions

---
 process/models/tfcoil/superconducting.py  | 459 ++++++++++++++--------
 tests/unit/models/tfcoil/test_sctfcoil.py |   2 +-
 2 files changed, 298 insertions(+), 163 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 6735b003a4..61d3f912a8 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -476,9 +476,48 @@ def output_general_superconducting_tf_info(self) -> None:
 
         # WP material fraction
         po.osubhd(self.outfile, "TF winding pack (WP) material area/fractions:")
+
+        po.ovarre(
+            self.outfile,
+            "Area of all turn insulation in WP [m²]",
+            "(a_tf_coil_wp_turn_insulation)",
+            self.data.tfcoil.a_tf_coil_wp_turn_insulation,
+        )
+        po.ovarre(
+            self.outfile,
+            "Total insulation area in TF coil (turn and WP) [m²]",
+            "(a_tf_coil_inboard_insulation)",
+            self.data.superconducting_tfcoil.a_tf_coil_inboard_insulation,
+        )
+        po.ovarre(
+            self.outfile,
+            "Total steel area in inboard TF coil (turn and case) [m²]",
+            "(a_tf_coil_inboard_steel)",
+            self.data.superconducting_tfcoil.a_tf_coil_inboard_steel,
+        )
+        po.ovarre(
+            self.outfile,
+            "Total conductor area in WP [m²]",
+            "(a_tf_wp_conductor)",
+            self.data.tfcoil.a_tf_wp_conductor,
+        )
+        po.ovarre(
+            self.outfile,
+            "Total additional void area in WP [m²]",
+            "(a_tf_wp_extra_void)",
+            self.data.tfcoil.a_tf_wp_extra_void,
+        )
+
+        po.ovarre(
+            self.outfile,
+            "Area of all coolant channels in WP [m²]",
+            "(a_tf_wp_coolant_channels)",
+            self.data.tfcoil.a_tf_wp_coolant_channels,
+        )
+
         po.ovarre(
             self.outfile,
-            "Steel WP cross-section (total) (m²)",
+            "Steel WP cross-section (total) [m²]",
             "(a_tf_wp_steel*n_tf_coils)",
             self.data.tfcoil.a_tf_wp_steel * self.data.tfcoil.n_tf_coils,
         )
@@ -522,9 +561,9 @@ def output_general_superconducting_tf_info(self) -> None:
             TFWPIntegerTurnType(self.data.tfcoil.i_tf_turns_integer)
             == TFWPIntegerTurnType.NON_INTEGER
         ):
-            po.ocmmnt(self.outfile, "  Non-integer number of turns")
+            po.ocmmnt(self.outfile, "->  Non-integer number of turns")
         else:
-            po.ocmmnt(self.outfile, "  Integer number of turns")
+            po.ocmmnt(self.outfile, "->  Integer number of turns")
 
         po.ovarre(
             self.outfile,
@@ -644,7 +683,7 @@ def output_general_superconducting_tf_info(self) -> None:
         po.oblnkl(self.outfile)
         po.ovarre(
             self.outfile,
-            "TF coil turn area (m²)",
+            "TF coil turn area [m²]",
             "(a_tf_turn)",
             self.data.tfcoil.a_tf_turn,
         )
@@ -661,6 +700,12 @@ def output_general_superconducting_tf_info(self) -> None:
             "(a_tf_turn_cable_space_effective)",
             self.data.superconducting_tfcoil.a_tf_turn_cable_space_effective,
         )
+        po.ovarre(
+            self.outfile,
+            "Area of steel in turn [m²]",
+            "(a_tf_turn_steel)",
+            self.data.tfcoil.a_tf_turn_steel,
+        )
 
         po.ovarre(
             self.outfile,
@@ -2225,6 +2270,21 @@ class TFGeneralTurnGeometry:
     dx_tf_turn_cable_space_average: float
 
 
+@dataclass(slots=True)
+class SuperconTFAreasFractions:
+    """Superconducting TF coil winding pack areas and fractions."""
+
+    a_tf_wp_coolant_channels: float
+    a_tf_wp_conductor: float
+    a_tf_wp_extra_void: float
+    a_tf_coil_wp_turn_insulation: float
+    a_tf_wp_steel: float
+    a_tf_coil_inboard_steel: float
+    f_a_tf_coil_inboard_steel: float
+    a_tf_coil_inboard_insulation: float
+    f_a_tf_coil_inboard_insulation: float
+
+
 @dataclass(slots=True)
 class CICCAveragedTurnGeometry(TFGeneralTurnGeometry):
     """Averaged turn geometry for a CICC conductor with LTS cables."""
@@ -2359,6 +2419,13 @@ def run(self, output: bool = False):
             self.data.superconducting_tfcoil.dx_tf_turn_cable_space_average = (
                 int_turn_geometry.dx_tf_turn_cable_space_average
             )
+            self.data.superconducting_tfcoil.a_tf_turn_cable_space_effective = (
+                int_turn_geometry.a_tf_turn_cable_space_effective
+            )
+            self.data.superconducting_tfcoil.f_a_tf_turn_cable_space_cooling = (
+                int_turn_geometry.f_a_tf_turn_cable_space_cooling
+            )
+            self.data.tfcoil.dx_tf_turn_general = int_turn_geometry.dx_tf_turn_general
 
         # Calculate number of cables in turn if CICC conductor
         # ---------------------------------------------------
@@ -2380,65 +2447,39 @@ def run(self, output: bool = False):
             n_tf_turn_superconducting_cables=d_sc_tf.n_tf_turn_superconducting_cables,
         )
 
-        # Areas and fractions
-        # -------------------
-        # Central helium channel down the conductor core [m2]
-        self.data.tfcoil.a_tf_wp_coolant_channels = (
-            0.25e0
-            * self.data.tfcoil.n_tf_coil_turns
-            * np.pi
-            * self.data.tfcoil.dia_tf_turn_coolant_channel**2
-        )
-
-        # Total conductor cross-sectional area, taking account of void area
-        # and central helium channel [m2]
-        self.data.tfcoil.a_tf_wp_conductor = (
-            self.data.tfcoil.a_tf_turn_cable_space_no_void
-            * self.data.tfcoil.n_tf_coil_turns
-            * (1.0e0 - self.data.tfcoil.f_a_tf_turn_cable_space_extra_void)
-            - self.data.tfcoil.a_tf_wp_coolant_channels
+        inboard_areas_fractions = self.tf_cicc_inboard_areas_and_fractions(
+            n_tf_coil_turns=self.data.tfcoil.n_tf_coil_turns,
+            dia_tf_turn_coolant_channel=self.data.tfcoil.dia_tf_turn_coolant_channel,
+            a_tf_turn_cable_space_no_void=self.data.tfcoil.a_tf_turn_cable_space_no_void,
+            f_a_tf_turn_cable_space_extra_void=self.data.tfcoil.f_a_tf_turn_cable_space_extra_void,
+            a_tf_turn_insulation=self.data.tfcoil.a_tf_turn_insulation,
+            a_tf_turn_steel=self.data.tfcoil.a_tf_turn_steel,
+            n_tf_coils=self.data.tfcoil.n_tf_coils,
+            a_tf_inboard_total=self.data.tfcoil.a_tf_inboard_total,
+            a_tf_coil_inboard_case=self.data.tfcoil.a_tf_coil_inboard_case,
+            a_tf_wp_ground_insulation=self.data.superconducting_tfcoil.a_tf_wp_ground_insulation,
         )
 
-        # Void area in conductor for He, not including central channel [m2]
-        self.data.tfcoil.a_tf_wp_extra_void = (
-            self.data.tfcoil.a_tf_turn_cable_space_no_void
-            * self.data.tfcoil.n_tf_coil_turns
-            * self.data.tfcoil.f_a_tf_turn_cable_space_extra_void
+        self.data.tfcoil.a_tf_wp_coolant_channels = (
+            inboard_areas_fractions.a_tf_wp_coolant_channels
         )
-
-        # Area of inter-turn insulation: total [m2]
+        self.data.tfcoil.a_tf_wp_conductor = inboard_areas_fractions.a_tf_wp_conductor
+        self.data.tfcoil.a_tf_wp_extra_void = inboard_areas_fractions.a_tf_wp_extra_void
         self.data.tfcoil.a_tf_coil_wp_turn_insulation = (
-            self.data.tfcoil.n_tf_coil_turns * self.data.tfcoil.a_tf_turn_insulation
-        )
-
-        # Area of steel structure in winding pack [m2]
-        self.data.tfcoil.a_tf_wp_steel = (
-            self.data.tfcoil.n_tf_coil_turns * self.data.tfcoil.a_tf_turn_steel
+            inboard_areas_fractions.a_tf_coil_wp_turn_insulation
         )
-
-        # Inboard coil steel area [m2]
-        d_sc_tf.a_tf_coil_inboard_steel = (
-            self.data.tfcoil.a_tf_coil_inboard_case + self.data.tfcoil.a_tf_wp_steel
+        self.data.tfcoil.a_tf_wp_steel = inboard_areas_fractions.a_tf_wp_steel
+        self.data.superconducting_tfcoil.a_tf_coil_inboard_steel = (
+            inboard_areas_fractions.a_tf_coil_inboard_steel
         )
-
-        # Inboard coil steel fraction [-]
-        d_sc_tf.f_a_tf_coil_inboard_steel = (
-            self.data.tfcoil.n_tf_coils
-            * d_sc_tf.a_tf_coil_inboard_steel
-            / self.data.tfcoil.a_tf_inboard_total
+        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_steel = (
+            inboard_areas_fractions.f_a_tf_coil_inboard_steel
         )
-
-        # Inboard coil insulation cross-section [m2]
-        d_sc_tf.a_tf_coil_inboard_insulation = (
-            self.data.tfcoil.a_tf_coil_wp_turn_insulation
-            + d_sc_tf.a_tf_wp_ground_insulation
+        self.data.superconducting_tfcoil.a_tf_coil_inboard_insulation = (
+            inboard_areas_fractions.a_tf_coil_inboard_insulation
         )
-
-        #  Inboard coil insulation fraction [-]
-        d_sc_tf.f_a_tf_coil_inboard_insulation = (
-            self.data.tfcoil.n_tf_coils
-            * d_sc_tf.a_tf_coil_inboard_insulation
-            / self.data.tfcoil.a_tf_inboard_total
+        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_insulation = (
+            inboard_areas_fractions.f_a_tf_coil_inboard_insulation
         )
 
         # Negative areas or fractions error reporting
@@ -3444,7 +3485,7 @@ def tf_cable_in_conduit_integer_turn_geometry(
             )
 
         # Average turn dimension [m]
-        data.tfcoil.dx_tf_turn_general = np.sqrt(dr_tf_turn * dx_tf_turn)
+        dx_tf_turn_general = np.sqrt(dr_tf_turn * dx_tf_turn)
 
         # Number of TF turns
         n_tf_coil_turns = np.double(n_tf_wp_layers * n_tf_wp_pancakes)
@@ -3476,7 +3517,7 @@ def tf_cable_in_conduit_integer_turn_geometry(
 
         # Calculate the true effective cable space by taking away the cooling
         # channel and the extra void fraction
-        data.superconducting_tfcoil.a_tf_turn_cable_space_effective = (
+        a_tf_turn_cable_space_effective = (
             a_tf_turn_cable_space_no_void
             -
             # Coolant channel area
@@ -3492,9 +3533,8 @@ def tf_cable_in_conduit_integer_turn_geometry(
             )
         )
 
-        data.superconducting_tfcoil.f_a_tf_turn_cable_space_cooling = 1 - (
-            data.superconducting_tfcoil.a_tf_turn_cable_space_effective
-            / a_tf_turn_cable_space_no_void
+        f_a_tf_turn_cable_space_cooling = 1 - (
+            a_tf_turn_cable_space_effective / a_tf_turn_cable_space_no_void
         )
 
         if a_tf_turn_cable_space_no_void <= 0.0e0:
@@ -3540,10 +3580,86 @@ def tf_cable_in_conduit_integer_turn_geometry(
             dr_tf_turn_cable_space=dr_tf_turn_cable_space,
             dx_tf_turn_cable_space=dx_tf_turn_cable_space,
             dx_tf_turn_cable_space_average=dx_tf_turn_cable_space_average,
+            a_tf_turn_cable_space_effective=a_tf_turn_cable_space_effective,
+            f_a_tf_turn_cable_space_cooling=f_a_tf_turn_cable_space_cooling,
+            dx_tf_turn_general=dx_tf_turn_general,
         )
 
         # -------------
 
+    @staticmethod
+    def tf_cicc_inboard_areas_and_fractions(
+        n_tf_coil_turns: int,
+        dia_tf_turn_coolant_channel: float,
+        a_tf_turn_cable_space_no_void: float,
+        f_a_tf_turn_cable_space_extra_void: float,
+        a_tf_turn_insulation: float,
+        a_tf_turn_steel: float,
+        n_tf_coils: int,
+        a_tf_inboard_total: float,
+        a_tf_coil_inboard_case: float,
+        a_tf_wp_ground_insulation: float,
+    ) -> SuperconTFAreasFractions:
+
+        # Areas and fractions
+        # -------------------
+        # Central helium channel down the conductor core [m2]
+        a_tf_wp_coolant_channels = (
+            0.25e0 * n_tf_coil_turns * np.pi * dia_tf_turn_coolant_channel**2
+        )
+
+        # Total conductor cross-sectional area, taking account of void area
+        # and central helium channel [m2]
+        a_tf_wp_conductor = (
+            a_tf_turn_cable_space_no_void
+            * n_tf_coil_turns
+            * (1.0e0 - f_a_tf_turn_cable_space_extra_void)
+            - a_tf_wp_coolant_channels
+        )
+
+        # Void area in conductor for He, not including central channel [m2]
+        a_tf_wp_extra_void = (
+            a_tf_turn_cable_space_no_void
+            * n_tf_coil_turns
+            * f_a_tf_turn_cable_space_extra_void
+        )
+
+        # Area of inter-turn insulation: total [m2]
+        a_tf_coil_wp_turn_insulation = n_tf_coil_turns * a_tf_turn_insulation
+
+        # Area of steel structure in winding pack [m2]
+        a_tf_wp_steel = n_tf_coil_turns * a_tf_turn_steel
+
+        # Inboard coil steel area [m2]
+        a_tf_coil_inboard_steel = a_tf_coil_inboard_case + a_tf_wp_steel
+
+        # Inboard coil steel fraction [-]
+        f_a_tf_coil_inboard_steel = (
+            n_tf_coils * a_tf_coil_inboard_steel / a_tf_inboard_total
+        )
+
+        # Inboard coil insulation cross-section [m2]
+        a_tf_coil_inboard_insulation = (
+            a_tf_coil_wp_turn_insulation + a_tf_wp_ground_insulation
+        )
+
+        #  Inboard coil insulation fraction [-]
+        f_a_tf_coil_inboard_insulation = (
+            n_tf_coils * a_tf_coil_inboard_insulation / a_tf_inboard_total
+        )
+
+        return SuperconTFAreasFractions(
+            a_tf_wp_coolant_channels=a_tf_wp_coolant_channels,
+            a_tf_wp_conductor=a_tf_wp_conductor,
+            a_tf_wp_extra_void=a_tf_wp_extra_void,
+            a_tf_coil_wp_turn_insulation=a_tf_coil_wp_turn_insulation,
+            a_tf_wp_steel=a_tf_wp_steel,
+            a_tf_coil_inboard_steel=a_tf_coil_inboard_steel,
+            f_a_tf_coil_inboard_steel=f_a_tf_coil_inboard_steel,
+            a_tf_coil_inboard_insulation=a_tf_coil_inboard_insulation,
+            f_a_tf_coil_inboard_insulation=f_a_tf_coil_inboard_insulation,
+        )
+
     def output_cable_in_conduit_cable_info(self) -> None:
         """
         Outputs the calculated cable in condutit cable space geometry information
@@ -3584,50 +3700,6 @@ def output_cable_in_conduit_cable_info(self) -> None:
         )
         po.oblnkl(self.outfile)
 
-        po.ovarre(
-            self.outfile,
-            "Area of steel in turn",
-            "(a_tf_turn_steel)",
-            self.data.tfcoil.a_tf_turn_steel,
-        )
-        po.ovarre(
-            self.outfile,
-            "Area of all turn insulation in WP",
-            "(a_tf_coil_wp_turn_insulation)",
-            self.data.tfcoil.a_tf_coil_wp_turn_insulation,
-        )
-        po.ovarre(
-            self.outfile,
-            "Total insulation area in TF coil (turn and WP)",
-            "(a_tf_coil_inboard_insulation)",
-            d_sc_tf.a_tf_coil_inboard_insulation,
-        )
-        po.ovarre(
-            self.outfile,
-            "Total steel area in inboard TF coil (turn and case)",
-            "(a_tf_coil_inboard_steel)",
-            d_sc_tf.a_tf_coil_inboard_steel,
-        )
-        po.ovarre(
-            self.outfile,
-            "Total conductor area in WP",
-            "(a_tf_wp_conductor)",
-            self.data.tfcoil.a_tf_wp_conductor,
-        )
-        po.ovarre(
-            self.outfile,
-            "Total additional void area in WP",
-            "(a_tf_wp_extra_void)",
-            self.data.tfcoil.a_tf_wp_extra_void,
-        )
-
-        po.ovarre(
-            self.outfile,
-            "Area of all coolant channels in WP",
-            "(a_tf_wp_coolant_channels)",
-            self.data.tfcoil.a_tf_wp_coolant_channels,
-        )
-
         po.ovarre(
             self.outfile,
             "Copper area fraction of cable conductor",
@@ -3641,6 +3713,8 @@ def output_cable_in_conduit_cable_info(self) -> None:
             1 - self.data.tfcoil.f_a_tf_turn_cable_copper,
         )
 
+        po.oblnkl(self.outfile)
+
         po.ovarre(
             self.outfile,
             "Elastic properties behavior",
@@ -3755,56 +3829,6 @@ def run(self, output: bool = False):
                 "Integer turn geometry not implemented for CroCo conductor."
             )
 
-        # Areas and fractions
-        # -------------------
-        # Central helium channel down the conductor core [m²]
-        # No central channel in CroCo conductor,
-        self.data.tfcoil.a_tf_wp_coolant_channels = 0.0
-
-        self.data.tfcoil.f_a_tf_turn_cable_space_extra_void = 0.0
-
-        # Void area in conductor for He, not including central channel [m²]
-        self.data.tfcoil.a_tf_wp_extra_void = (
-            self.data.tfcoil.a_tf_turn_cable_space_no_void
-            * self.data.tfcoil.n_tf_coil_turns
-            * self.data.tfcoil.f_a_tf_turn_cable_space_extra_void
-        )
-
-        # Area of inter-turn insulation: total [m²]
-        self.data.tfcoil.a_tf_coil_wp_turn_insulation = (
-            self.data.tfcoil.n_tf_coil_turns * self.data.tfcoil.a_tf_turn_insulation
-        )
-
-        # Area of steel structure in winding pack [m²]
-        self.data.tfcoil.a_tf_wp_steel = (
-            self.data.tfcoil.n_tf_coil_turns * self.data.tfcoil.a_tf_turn_steel
-        )
-
-        # Inboard coil steel area [m²]
-        d_sc_tf.a_tf_coil_inboard_steel = (
-            self.data.tfcoil.a_tf_coil_inboard_case + self.data.tfcoil.a_tf_wp_steel
-        )
-
-        # Inboard coil steel fraction [-]
-        d_sc_tf.f_a_tf_coil_inboard_steel = (
-            self.data.tfcoil.n_tf_coils
-            * d_sc_tf.a_tf_coil_inboard_steel
-            / self.data.tfcoil.a_tf_inboard_total
-        )
-
-        # Inboard coil insulation cross-section [m²]
-        d_sc_tf.a_tf_coil_inboard_insulation = (
-            self.data.tfcoil.a_tf_coil_wp_turn_insulation
-            + d_sc_tf.a_tf_wp_ground_insulation
-        )
-
-        #  Inboard coil insulation fraction [-]
-        d_sc_tf.f_a_tf_coil_inboard_insulation = (
-            self.data.tfcoil.n_tf_coils
-            * d_sc_tf.a_tf_coil_inboard_insulation
-            / self.data.tfcoil.a_tf_inboard_total
-        )
-
         croco_cable_space_geometry: CroCoCableSpaceGeometry = self.tf_turn_croco_cable_space_properties(
             dx_tf_turn_conduit_full_average=self.data.tfcoil.dx_tf_turn_conduit_full_average,
             dx_tf_turn_steel=self.data.tfcoil.dx_tf_turn_steel,
@@ -3853,11 +3877,57 @@ def run(self, output: bool = False):
             croco_cable_geometry.dx_croco_strand_tape_stack
         )
 
-        d_sc_tf.a_tf_croco_strand_copper_total = d_sc_tf.a_tf_croco_strand_copper_total
-        d_sc_tf.a_tf_croco_strand_hastelloy = d_sc_tf.a_tf_croco_strand_hastelloy
-        d_sc_tf.a_tf_croco_strand_solder = d_sc_tf.a_tf_croco_strand_solder
-        d_sc_tf.a_tf_croco_strand_rebco = d_sc_tf.a_tf_croco_strand_rebco
-        d_sc_tf.a_tf_croco_strand = d_sc_tf.a_tf_croco_strand
+        self.data.superconducting_tfcoil.a_tf_croco_strand_copper_total = (
+            self.data.superconducting_tfcoil.a_tf_croco_strand_copper_total
+        )
+        self.data.superconducting_tfcoil.a_tf_croco_strand_hastelloy = (
+            self.data.superconducting_tfcoil.a_tf_croco_strand_hastelloy
+        )
+        self.data.superconducting_tfcoil.a_tf_croco_strand_solder = (
+            self.data.superconducting_tfcoil.a_tf_croco_strand_solder
+        )
+        self.data.superconducting_tfcoil.a_tf_croco_strand_rebco = (
+            self.data.superconducting_tfcoil.a_tf_croco_strand_rebco
+        )
+        self.data.superconducting_tfcoil.a_tf_croco_strand = (
+            self.data.superconducting_tfcoil.a_tf_croco_strand
+        )
+
+        self.data.tfcoil.f_a_tf_turn_cable_space_extra_void = 0.0
+
+        inbaord_areas_fractions = self.tf_croco_inboard_areas_and_fractions(
+            a_tf_turn_cable_space_no_void=self.data.tfcoil.a_tf_turn_cable_space_no_void,
+            n_tf_coil_turns=self.data.tfcoil.n_tf_coil_turns,
+            f_a_tf_turn_cable_space_extra_void=self.data.tfcoil.f_a_tf_turn_cable_space_extra_void,
+            a_tf_turn_insulation=self.data.tfcoil.a_tf_turn_insulation,
+            a_tf_turn_steel=self.data.tfcoil.a_tf_turn_steel,
+            a_tf_coil_inboard_case=self.data.tfcoil.a_tf_coil_inboard_case,
+            n_tf_coils=self.data.tfcoil.n_tf_coils,
+            a_tf_inboard_total=self.data.tfcoil.a_tf_inboard_total,
+            a_tf_wp_ground_insulation=self.data.superconducting_tfcoil.a_tf_wp_ground_insulation,
+            a_tf_croco_strand=self.data.superconducting_tfcoil.a_tf_croco_strand,
+        )
+        self.data.tfcoil.a_tf_wp_coolant_channels = (
+            inbaord_areas_fractions.a_tf_wp_coolant_channels
+        )
+        self.data.tfcoil.a_tf_wp_conductor = inbaord_areas_fractions.a_tf_wp_conductor
+        self.data.tfcoil.a_tf_wp_extra_void = inbaord_areas_fractions.a_tf_wp_extra_void
+        self.data.tfcoil.a_tf_coil_wp_turn_insulation = (
+            inbaord_areas_fractions.a_tf_coil_wp_turn_insulation
+        )
+        self.data.tfcoil.a_tf_wp_steel = inbaord_areas_fractions.a_tf_wp_steel
+        self.data.superconducting_tfcoil.a_tf_coil_inboard_steel = (
+            inbaord_areas_fractions.a_tf_coil_inboard_steel
+        )
+        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_steel = (
+            inbaord_areas_fractions.f_a_tf_coil_inboard_steel
+        )
+        self.data.superconducting_tfcoil.a_tf_coil_inboard_insulation = (
+            inbaord_areas_fractions.a_tf_coil_inboard_insulation
+        )
+        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_insulation = (
+            inbaord_areas_fractions.f_a_tf_coil_inboard_insulation
+        )
 
         # Area of core = area of strand
         d_sc_tf.a_tf_turn_croco_copper_bar = d_sc_tf.a_tf_croco_strand
@@ -3933,9 +4003,9 @@ def run(self, output: bool = False):
 
         self.data.superconducting_tfcoil.b_tf_superconductor_critical_zero_temp_strain = superconductor_critical_properties.bc20m
         self.data.superconducting_tfcoil.temp_tf_superconductor_critical_zero_field_strain = superconductor_critical_properties.tc0m
-        self.data.superconducting_tfcoil.c_tf_turn_cables_critical = (
-            superconductor_critical_properties.c_turn_cables_critical
-        )
+        self.data.superconducting_tfcoil.cur_tf_turn_croco_strand_critical = (
+            self.data.superconducting_tfcoil.c_tf_turn_cables_critical
+        ) = superconductor_critical_properties.c_turn_cables_critical
 
         if self.data.tfcoil.i_str_wp == 0:
             strain = self.data.tfcoil.str_tf_con_res
@@ -4550,6 +4620,71 @@ def tf_turn_croco_cable_space_properties(
             f_a_tf_turn_cable_space_cooling=f_a_tf_turn_cable_space_cooling,
         )
 
+    @staticmethod
+    def tf_croco_inboard_areas_and_fractions(
+        a_tf_turn_cable_space_no_void: float,
+        n_tf_coil_turns: int,
+        f_a_tf_turn_cable_space_extra_void: float,
+        a_tf_turn_insulation: float,
+        a_tf_turn_steel: float,
+        a_tf_coil_inboard_case: float,
+        n_tf_coils: int,
+        a_tf_inboard_total: float,
+        a_tf_wp_ground_insulation: float,
+        a_tf_croco_strand: float,
+    ) -> SuperconTFAreasFractions:
+
+        # Areas and fractions
+        # -------------------
+        # Central helium channel down the conductor core [m²]
+        # No central channel in CroCo conductor,
+        a_tf_wp_coolant_channels = 0.0
+
+        a_tf_wp_conductor = n_tf_coil_turns * a_tf_croco_strand * N_CROCO_STRANDS_TURN
+
+        # Void area in conductor for He, not including central channel [m²]
+        a_tf_wp_extra_void = (
+            a_tf_turn_cable_space_no_void
+            * n_tf_coil_turns
+            * f_a_tf_turn_cable_space_extra_void
+        )
+
+        # Area of inter-turn insulation: total [m²]
+        a_tf_coil_wp_turn_insulation = n_tf_coil_turns * a_tf_turn_insulation
+
+        # Area of steel structure in winding pack [m²]
+        a_tf_wp_steel = n_tf_coil_turns * a_tf_turn_steel
+
+        # Inboard coil steel area [m²]
+        a_tf_coil_inboard_steel = a_tf_coil_inboard_case + a_tf_wp_steel
+
+        # Inboard coil steel fraction [-]
+        f_a_tf_coil_inboard_steel = (
+            n_tf_coils * a_tf_coil_inboard_steel / a_tf_inboard_total
+        )
+
+        # Inboard coil insulation cross-section [m²]
+        a_tf_coil_inboard_insulation = (
+            a_tf_coil_wp_turn_insulation + a_tf_wp_ground_insulation
+        )
+
+        #  Inboard coil insulation fraction [-]
+        f_a_tf_coil_inboard_insulation = (
+            n_tf_coils * a_tf_coil_inboard_insulation / a_tf_inboard_total
+        )
+
+        return SuperconTFAreasFractions(
+            a_tf_wp_coolant_channels=a_tf_wp_coolant_channels,
+            a_tf_wp_conductor=a_tf_wp_conductor,
+            a_tf_wp_extra_void=a_tf_wp_extra_void,
+            a_tf_coil_wp_turn_insulation=a_tf_coil_wp_turn_insulation,
+            a_tf_wp_steel=a_tf_wp_steel,
+            a_tf_coil_inboard_steel=a_tf_coil_inboard_steel,
+            f_a_tf_coil_inboard_steel=f_a_tf_coil_inboard_steel,
+            a_tf_coil_inboard_insulation=a_tf_coil_inboard_insulation,
+            f_a_tf_coil_inboard_insulation=f_a_tf_coil_inboard_insulation,
+        )
+
     def croco_voltage(self) -> float:
         """Calculates CROCO voltage"""
         d_sc_tf = self.data.superconducting_tfcoil
diff --git a/tests/unit/models/tfcoil/test_sctfcoil.py b/tests/unit/models/tfcoil/test_sctfcoil.py
index 8f1be0cc3a..250be182e2 100644
--- a/tests/unit/models/tfcoil/test_sctfcoil.py
+++ b/tests/unit/models/tfcoil/test_sctfcoil.py
@@ -1158,7 +1158,7 @@ def test_tf_cable_in_conduit_integer_turn_geometry(
         tfintegerturngeomparam.expected_t_conductor
     )
 
-    assert cicc_sctfcoil.data.tfcoil.dx_tf_turn_general == pytest.approx(
+    assert integer_turn_geometry.dx_tf_turn_general == pytest.approx(
         tfintegerturngeomparam.expected_dx_tf_turn_general
     )
 

From b1b17ca7bd88886adb46485c63ed1fec7be70499 Mon Sep 17 00:00:00 2001
From: mn3981 <christopher.ashe@ukaea.uk>
Date: Mon, 22 Jun 2026 10:53:14 +0100
Subject: [PATCH 19/21] Update test values to try and align with previous
 solution

---
 process/core/input.py                              | 14 --------------
 .../input_files/spherical_tokamak_eval.IN.DAT      |  4 ++++
 tests/regression/input_files/st_regression.IN.DAT  |  6 ++++++
 3 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/process/core/input.py b/process/core/input.py
index 8f5d7512c4..580fcb7392 100644
--- a/process/core/input.py
+++ b/process/core/input.py
@@ -710,20 +710,6 @@ def bounds(self) -> tuple[NumberType | None, NumberType | None]:
         "superconducting_tfcoil",
         float,
         range=(1e-08, 0.0001),
-        additional_actions=lambda _n, rt, *_: (
-            rt <= 1e-6
-            or logger.warning(
-                (
-                    "the relationship between REBCO layer thickness "
-                    "and current density is not linear."
-                    "REBCO layer thicknesses > 1um should be considered "
-                    "an aggressive extrapolation of"
-                    "current HTS technology and any results "
-                    "must be considered speculative."
-                ),
-                stacklevel=1,
-            )
-        ),
     ),
     "redun_vacp": InputVariable("costs", float, range=(0.0, 100.0)),
     "residual_sig_hoop": InputVariable("cs_fatigue", float, range=(0.0, 1000000000.0)),
diff --git a/tests/regression/input_files/spherical_tokamak_eval.IN.DAT b/tests/regression/input_files/spherical_tokamak_eval.IN.DAT
index 29ab2a1bae..2bed0aa45a 100644
--- a/tests/regression/input_files/spherical_tokamak_eval.IN.DAT
+++ b/tests/regression/input_files/spherical_tokamak_eval.IN.DAT
@@ -70,6 +70,10 @@ iohcl    = 0 * Switch for existence of central solenoid;
 i_cs_precomp = 0 * Switch for existence of central solenoid pre-compression structure;
 i_tf_inside_cs = 0 * Switch for placing the TF coil inside the CS
 i_tf_turn_type = 2 * CroCo Turn geometry for HTS Tapes
+dx_tf_hts_tape_rebco = 1.0e-6
+dx_tf_croco_strand_copper = 2.0e-3
+dx_tf_hts_tape_copper = 2.0e-4
+dx_tf_hts_tape_hastelloy = 1e-5
 dr_cs    = 0.20016400484967947 * Central solenoid thickness (m) (`iteration variable 16`)
 i_r_cp_top = 2 * Switch selecting the he parametrization of the outer radius of the top of the CP part of the TF coil
 dr_fw_plasma_gap_inboard  = 0.1 * Gap between plasma and first wall; inboard side (m) (if `i_plasma_wall_gap=1`)
diff --git a/tests/regression/input_files/st_regression.IN.DAT b/tests/regression/input_files/st_regression.IN.DAT
index 37f34ed113..c8f51637b6 100644
--- a/tests/regression/input_files/st_regression.IN.DAT
+++ b/tests/regression/input_files/st_regression.IN.DAT
@@ -784,6 +784,12 @@ p_plasma_separatrix_rmajor_max_mw = 40.0
 *-------------------------------- *TF Coil* --------------------------------------------------------------------------------------------------------------------------------------------------------------*
 *‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾*
 
+dx_tf_hts_tape_rebco = 1.0e-6
+dx_tf_croco_strand_copper = 2.0e-3
+dx_tf_hts_tape_copper = 2.0e-4
+dx_tf_hts_tape_hastelloy = 1e-5
+
+
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ General settings ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
 

From f72950741a1622e366b8531f6afe19d10c23823b Mon Sep 17 00:00:00 2001
From: Timothy Nunn <timothy.nunn@ukaea.uk>
Date: Thu, 6 Aug 2026 13:37:30 +0100
Subject: [PATCH 20/21] Fix some ruff errors and some merge mistakes

---
 process/models/tfcoil/superconducting.py | 210 ++++++++++-------------
 1 file changed, 94 insertions(+), 116 deletions(-)

diff --git a/process/models/tfcoil/superconducting.py b/process/models/tfcoil/superconducting.py
index 61d3f912a8..9872820052 100644
--- a/process/models/tfcoil/superconducting.py
+++ b/process/models/tfcoil/superconducting.py
@@ -487,13 +487,13 @@ def output_general_superconducting_tf_info(self) -> None:
             self.outfile,
             "Total insulation area in TF coil (turn and WP) [m²]",
             "(a_tf_coil_inboard_insulation)",
-            self.data.superconducting_tfcoil.a_tf_coil_inboard_insulation,
+            d_sc_tf.a_tf_coil_inboard_insulation,
         )
         po.ovarre(
             self.outfile,
             "Total steel area in inboard TF coil (turn and case) [m²]",
             "(a_tf_coil_inboard_steel)",
-            self.data.superconducting_tfcoil.a_tf_coil_inboard_steel,
+            d_sc_tf.a_tf_coil_inboard_steel,
         )
         po.ovarre(
             self.outfile,
@@ -611,14 +611,14 @@ def output_general_superconducting_tf_info(self) -> None:
                 self.outfile,
                 "Radial width of conductor (m)",
                 "(dr_tf_turn_conduit_full)",
-                self.data.superconducting_tfcoil.dr_tf_turn_conduit_full,
+                d_sc_tf.dr_tf_turn_conduit_full,
                 "OP ",
             )
             po.ovarre(
                 self.outfile,
                 "Toroidal width of conductor (m)",
                 "(dx_tf_turn_conduit_full_toroidal)",
-                self.data.superconducting_tfcoil.dx_tf_turn_conduit_full_toroidal,
+                d_sc_tf.dx_tf_turn_conduit_full_toroidal,
                 "OP ",
             )
             po.ovarre(
@@ -698,7 +698,7 @@ def output_general_superconducting_tf_info(self) -> None:
             self.outfile,
             "True area of turn cable space usable by conductor [m²]",
             "(a_tf_turn_cable_space_effective)",
-            self.data.superconducting_tfcoil.a_tf_turn_cable_space_effective,
+            d_sc_tf.a_tf_turn_cable_space_effective,
         )
         po.ovarre(
             self.outfile,
@@ -2354,12 +2354,12 @@ def run(self, output: bool = False):
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
             self.data.tfcoil.c_tf_turn = avg_turn_geometry.c_tf_turn
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
-            self.data.superconducting_tfcoil.dr_tf_turn = avg_turn_geometry.dr_tf_turn
-            self.data.superconducting_tfcoil.dx_tf_turn = avg_turn_geometry.dx_tf_turn
+            d_sc_tf.dr_tf_turn = avg_turn_geometry.dr_tf_turn
+            d_sc_tf.dx_tf_turn = avg_turn_geometry.dx_tf_turn
             self.data.tfcoil.dx_tf_turn_conduit_full_average = (
                 avg_turn_geometry.dx_tf_turn_conduit_full_average
             )
-            self.data.superconducting_tfcoil.radius_tf_turn_cable_space_corners = (
+            d_sc_tf.radius_tf_turn_cable_space_corners = (
                 avg_turn_geometry.radius_tf_turn_cable_space_corners
             )
             d_sc_tf.dx_tf_turn_cable_space_average = (
@@ -2401,28 +2401,22 @@ def run(self, output: bool = False):
             )
             self.data.tfcoil.c_tf_turn = int_turn_geometry.c_tf_turn
             self.data.tfcoil.n_tf_coil_turns = int_turn_geometry.n_tf_coil_turns
-            self.data.superconducting_tfcoil.dr_tf_turn_conduit_full = (
-                int_turn_geometry.dr_tf_turn_conduit_full
-            )
-            self.data.superconducting_tfcoil.dx_tf_turn_conduit_full_toroidal = (
+            d_sc_tf.dr_tf_turn_conduit_full = int_turn_geometry.dr_tf_turn_conduit_full
+            d_sc_tf.dx_tf_turn_conduit_full_toroidal = (
                 int_turn_geometry.dx_tf_turn_conduit_full_toroidal
             )
             self.data.tfcoil.dx_tf_turn_conduit_full_average = (
                 int_turn_geometry.dx_tf_turn_conduit_full_average
             )
-            self.data.superconducting_tfcoil.dr_tf_turn_cable_space = (
-                int_turn_geometry.dr_tf_turn_cable_space
-            )
-            self.data.superconducting_tfcoil.dx_tf_turn_cable_space = (
-                int_turn_geometry.dx_tf_turn_cable_space
-            )
-            self.data.superconducting_tfcoil.dx_tf_turn_cable_space_average = (
+            d_sc_tf.dr_tf_turn_cable_space = int_turn_geometry.dr_tf_turn_cable_space
+            d_sc_tf.dx_tf_turn_cable_space = int_turn_geometry.dx_tf_turn_cable_space
+            d_sc_tf.dx_tf_turn_cable_space_average = (
                 int_turn_geometry.dx_tf_turn_cable_space_average
             )
-            self.data.superconducting_tfcoil.a_tf_turn_cable_space_effective = (
+            d_sc_tf.a_tf_turn_cable_space_effective = (
                 int_turn_geometry.a_tf_turn_cable_space_effective
             )
-            self.data.superconducting_tfcoil.f_a_tf_turn_cable_space_cooling = (
+            d_sc_tf.f_a_tf_turn_cable_space_cooling = (
                 int_turn_geometry.f_a_tf_turn_cable_space_cooling
             )
             self.data.tfcoil.dx_tf_turn_general = int_turn_geometry.dx_tf_turn_general
@@ -2457,7 +2451,7 @@ def run(self, output: bool = False):
             n_tf_coils=self.data.tfcoil.n_tf_coils,
             a_tf_inboard_total=self.data.tfcoil.a_tf_inboard_total,
             a_tf_coil_inboard_case=self.data.tfcoil.a_tf_coil_inboard_case,
-            a_tf_wp_ground_insulation=self.data.superconducting_tfcoil.a_tf_wp_ground_insulation,
+            a_tf_wp_ground_insulation=d_sc_tf.a_tf_wp_ground_insulation,
         )
 
         self.data.tfcoil.a_tf_wp_coolant_channels = (
@@ -2469,16 +2463,14 @@ def run(self, output: bool = False):
             inboard_areas_fractions.a_tf_coil_wp_turn_insulation
         )
         self.data.tfcoil.a_tf_wp_steel = inboard_areas_fractions.a_tf_wp_steel
-        self.data.superconducting_tfcoil.a_tf_coil_inboard_steel = (
-            inboard_areas_fractions.a_tf_coil_inboard_steel
-        )
-        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_steel = (
+        d_sc_tf.a_tf_coil_inboard_steel = inboard_areas_fractions.a_tf_coil_inboard_steel
+        d_sc_tf.f_a_tf_coil_inboard_steel = (
             inboard_areas_fractions.f_a_tf_coil_inboard_steel
         )
-        self.data.superconducting_tfcoil.a_tf_coil_inboard_insulation = (
+        d_sc_tf.a_tf_coil_inboard_insulation = (
             inboard_areas_fractions.a_tf_coil_inboard_insulation
         )
-        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_insulation = (
+        d_sc_tf.f_a_tf_coil_inboard_insulation = (
             inboard_areas_fractions.f_a_tf_coil_inboard_insulation
         )
 
@@ -3812,12 +3804,12 @@ def run(self, output: bool = False):
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
             self.data.tfcoil.c_tf_turn = avg_turn_geometry.c_tf_turn
             self.data.tfcoil.dx_tf_turn_general = avg_turn_geometry.dx_tf_turn_general
-            self.data.superconducting_tfcoil.dr_tf_turn = avg_turn_geometry.dr_tf_turn
-            self.data.superconducting_tfcoil.dx_tf_turn = avg_turn_geometry.dx_tf_turn
+            d_sc_tf.dr_tf_turn = avg_turn_geometry.dr_tf_turn
+            d_sc_tf.dx_tf_turn = avg_turn_geometry.dx_tf_turn
             self.data.tfcoil.dx_tf_turn_conduit_full_average = (
                 avg_turn_geometry.dx_tf_turn_conduit_full_average
             )
-            self.data.superconducting_tfcoil.dx_tf_turn_cable_space_average = (
+            d_sc_tf.dx_tf_turn_cable_space_average = (
                 avg_turn_geometry.dx_tf_turn_cable_space_average
             )
 
@@ -3829,7 +3821,7 @@ def run(self, output: bool = False):
                 "Integer turn geometry not implemented for CroCo conductor."
             )
 
-        croco_cable_space_geometry: CroCoCableSpaceGeometry = self.tf_turn_croco_cable_space_properties(
+        croco_cable_space_geometry = self.tf_turn_croco_cable_space_properties(
             dx_tf_turn_conduit_full_average=self.data.tfcoil.dx_tf_turn_conduit_full_average,
             dx_tf_turn_steel=self.data.tfcoil.dx_tf_turn_steel,
         )
@@ -3844,7 +3836,7 @@ def run(self, output: bool = False):
             croco_cable_space_geometry.a_tf_turn_cable_space_effective
         )
         self.data.tfcoil.a_tf_turn_steel = croco_cable_space_geometry.a_tf_turn_steel
-        self.data.superconducting_tfcoil.f_a_tf_turn_cable_space_cooling = (
+        d_sc_tf.f_a_tf_turn_cable_space_cooling = (
             croco_cable_space_geometry.f_a_tf_turn_cable_space_cooling
         )
 
@@ -3877,21 +3869,11 @@ def run(self, output: bool = False):
             croco_cable_geometry.dx_croco_strand_tape_stack
         )
 
-        self.data.superconducting_tfcoil.a_tf_croco_strand_copper_total = (
-            self.data.superconducting_tfcoil.a_tf_croco_strand_copper_total
-        )
-        self.data.superconducting_tfcoil.a_tf_croco_strand_hastelloy = (
-            self.data.superconducting_tfcoil.a_tf_croco_strand_hastelloy
-        )
-        self.data.superconducting_tfcoil.a_tf_croco_strand_solder = (
-            self.data.superconducting_tfcoil.a_tf_croco_strand_solder
-        )
-        self.data.superconducting_tfcoil.a_tf_croco_strand_rebco = (
-            self.data.superconducting_tfcoil.a_tf_croco_strand_rebco
-        )
-        self.data.superconducting_tfcoil.a_tf_croco_strand = (
-            self.data.superconducting_tfcoil.a_tf_croco_strand
-        )
+        d_sc_tf.a_tf_croco_strand_copper_total = d_sc_tf.a_tf_croco_strand_copper_total
+        d_sc_tf.a_tf_croco_strand_hastelloy = d_sc_tf.a_tf_croco_strand_hastelloy
+        d_sc_tf.a_tf_croco_strand_solder = d_sc_tf.a_tf_croco_strand_solder
+        d_sc_tf.a_tf_croco_strand_rebco = d_sc_tf.a_tf_croco_strand_rebco
+        d_sc_tf.a_tf_croco_strand = d_sc_tf.a_tf_croco_strand
 
         self.data.tfcoil.f_a_tf_turn_cable_space_extra_void = 0.0
 
@@ -3904,8 +3886,8 @@ def run(self, output: bool = False):
             a_tf_coil_inboard_case=self.data.tfcoil.a_tf_coil_inboard_case,
             n_tf_coils=self.data.tfcoil.n_tf_coils,
             a_tf_inboard_total=self.data.tfcoil.a_tf_inboard_total,
-            a_tf_wp_ground_insulation=self.data.superconducting_tfcoil.a_tf_wp_ground_insulation,
-            a_tf_croco_strand=self.data.superconducting_tfcoil.a_tf_croco_strand,
+            a_tf_wp_ground_insulation=d_sc_tf.a_tf_wp_ground_insulation,
+            a_tf_croco_strand=d_sc_tf.a_tf_croco_strand,
         )
         self.data.tfcoil.a_tf_wp_coolant_channels = (
             inbaord_areas_fractions.a_tf_wp_coolant_channels
@@ -3916,16 +3898,14 @@ def run(self, output: bool = False):
             inbaord_areas_fractions.a_tf_coil_wp_turn_insulation
         )
         self.data.tfcoil.a_tf_wp_steel = inbaord_areas_fractions.a_tf_wp_steel
-        self.data.superconducting_tfcoil.a_tf_coil_inboard_steel = (
-            inbaord_areas_fractions.a_tf_coil_inboard_steel
-        )
-        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_steel = (
+        d_sc_tf.a_tf_coil_inboard_steel = inbaord_areas_fractions.a_tf_coil_inboard_steel
+        d_sc_tf.f_a_tf_coil_inboard_steel = (
             inbaord_areas_fractions.f_a_tf_coil_inboard_steel
         )
-        self.data.superconducting_tfcoil.a_tf_coil_inboard_insulation = (
+        d_sc_tf.a_tf_coil_inboard_insulation = (
             inbaord_areas_fractions.a_tf_coil_inboard_insulation
         )
-        self.data.superconducting_tfcoil.f_a_tf_coil_inboard_insulation = (
+        d_sc_tf.f_a_tf_coil_inboard_insulation = (
             inbaord_areas_fractions.f_a_tf_coil_inboard_insulation
         )
 
@@ -3939,26 +3919,20 @@ def run(self, output: bool = False):
         # Total conductor cross-sectional area, taking account of void area
         # and central helium channel [m²]
         self.data.tfcoil.a_tf_wp_conductor = (
-            N_CROCO_STRANDS_TURN * self.data.superconducting_tfcoil.a_tf_croco_strand
+            N_CROCO_STRANDS_TURN * d_sc_tf.a_tf_croco_strand
         ) * self.data.tfcoil.n_tf_coil_turns
 
-        self.data.superconducting_tfcoil.a_tf_turn_copper_total = (
-            self.data.superconducting_tfcoil.a_tf_turn_croco_cable_space_copper
-        )
+        d_sc_tf.a_tf_turn_copper_total = d_sc_tf.a_tf_turn_croco_cable_space_copper
 
-        self.data.superconducting_tfcoil.f_a_tf_turn_copper = (
-            self.data.superconducting_tfcoil.a_tf_turn_croco_cable_space_copper
-            / self.data.tfcoil.a_tf_turn
+        d_sc_tf.f_a_tf_turn_copper = (
+            d_sc_tf.a_tf_turn_croco_cable_space_copper / self.data.tfcoil.a_tf_turn
         )
 
-        self.data.superconducting_tfcoil.f_a_tf_turn_cable_space_cooling = (
+        d_sc_tf.f_a_tf_turn_cable_space_cooling = (
             self.data.tfcoil.a_tf_turn_cable_space_no_void
             - (
-                (
-                    N_CROCO_STRANDS_TURN
-                    * self.data.superconducting_tfcoil.a_tf_croco_strand
-                )
-                - self.data.superconducting_tfcoil.a_tf_turn_croco_copper_bar
+                (N_CROCO_STRANDS_TURN * d_sc_tf.a_tf_croco_strand)
+                - d_sc_tf.a_tf_turn_croco_copper_bar
             )
         ) / self.data.tfcoil.a_tf_turn_cable_space_no_void
 
@@ -3973,55 +3947,59 @@ def run(self, output: bool = False):
             * self.data.tfcoil.n_tf_coil_turns
         )
 
-        superconductor_critical_properties: TFSuperconductorLimits = self.tf_croco_superconductor_properties(
-            a_tf_turn=self.data.tfcoil.a_tf_turn,
-            b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
-            cur_tf_turn=self.data.tfcoil.c_tf_turn,
-            temp_tf_peak=self.data.tfcoil.tftmp,
-            i_tf_superconductor=self.data.tfcoil.i_tf_sc_mat,
-            dr_tf_hts_tape=self.data.superconducting_tfcoil.dr_tf_hts_tape,
-            dx_tf_hts_tape_rebco=self.data.superconducting_tfcoil.dx_tf_hts_tape_rebco,
-            dx_tf_hts_tape_total=self.data.superconducting_tfcoil.dx_tf_hts_tape_total,
-            a_tf_croco_strand=self.data.superconducting_tfcoil.a_tf_croco_strand,
+        superconductor_critical_properties: TFSuperconductorLimits = (
+            self.tf_croco_superconductor_properties(
+                a_tf_turn=self.data.tfcoil.a_tf_turn,
+                b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
+                cur_tf_turn=self.data.tfcoil.c_tf_turn,
+                temp_tf_peak=self.data.tfcoil.tftmp,
+                i_tf_superconductor=self.data.tfcoil.i_tf_sc_mat,
+                dr_tf_hts_tape=d_sc_tf.dr_tf_hts_tape,
+                dx_tf_hts_tape_rebco=d_sc_tf.dx_tf_hts_tape_rebco,
+                dx_tf_hts_tape_total=d_sc_tf.dx_tf_hts_tape_total,
+                a_tf_croco_strand=d_sc_tf.a_tf_croco_strand,
+            )
         )
 
         self.data.tfcoil.j_tf_wp_critical = (
             superconductor_critical_properties.j_tf_wp_critical
         )
-        self.data.superconducting_tfcoil.j_tf_superconductor_critical = (
+        d_sc_tf.j_tf_superconductor_critical = (
             superconductor_critical_properties.j_superconductor_critical
         )
-        self.data.superconducting_tfcoil.f_c_tf_turn_operating_critical = (
+        d_sc_tf.f_c_tf_turn_operating_critical = (
             superconductor_critical_properties.f_c_tf_turn_operating_critical
         )
-        self.data.superconducting_tfcoil.j_tf_superconductor = (
-            superconductor_critical_properties.j_superconductor
+        d_sc_tf.j_tf_superconductor = superconductor_critical_properties.j_superconductor
+        d_sc_tf.j_tf_coil_turn = superconductor_critical_properties.j_tf_coil_turn
+
+        d_sc_tf.b_tf_superconductor_critical_zero_temp_strain = (
+            superconductor_critical_properties.bc20m
+        )
+        d_sc_tf.temp_tf_superconductor_critical_zero_field_strain = (
+            superconductor_critical_properties.tc0m
         )
-        self.data.superconducting_tfcoil.j_tf_coil_turn = (
-            superconductor_critical_properties.j_tf_coil_turn
+        d_sc_tf.cur_tf_turn_croco_strand_critical = d_sc_tf.c_tf_turn_cables_critical = (
+            superconductor_critical_properties.c_turn_cables_critical
         )
 
-        self.data.superconducting_tfcoil.b_tf_superconductor_critical_zero_temp_strain = superconductor_critical_properties.bc20m
-        self.data.superconducting_tfcoil.temp_tf_superconductor_critical_zero_field_strain = superconductor_critical_properties.tc0m
-        self.data.superconducting_tfcoil.cur_tf_turn_croco_strand_critical = (
-            self.data.superconducting_tfcoil.c_tf_turn_cables_critical
-        ) = superconductor_critical_properties.c_turn_cables_critical
-
         if self.data.tfcoil.i_str_wp == 0:
             strain = self.data.tfcoil.str_tf_con_res
         else:
             strain = self.data.tfcoil.str_wp
 
-        self.data.tfcoil.temp_tf_superconductor_margin = self.calculate_superconductor_temperature_margin(
-            i_tf_superconductor=self.data.tfcoil.i_tf_sc_mat,
-            j_superconductor=self.data.superconducting_tfcoil.j_tf_superconductor,
-            b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
-            strain=strain,
-            bc20m=self.data.superconducting_tfcoil.b_tf_superconductor_critical_zero_temp_strain,
-            tc0m=self.data.superconducting_tfcoil.temp_tf_superconductor_critical_zero_field_strain,
-            c0=1.0e10,
-            temp_tf_coolant_peak_field=self.data.tfcoil.tftmp,
-            data=self.data,
+        self.data.tfcoil.temp_tf_superconductor_margin = (
+            self.calculate_superconductor_temperature_margin(
+                i_tf_superconductor=self.data.tfcoil.i_tf_sc_mat,
+                j_superconductor=d_sc_tf.j_tf_superconductor,
+                b_tf_inboard_peak=self.data.tfcoil.b_tf_inboard_peak_with_ripple,
+                strain=strain,
+                bc20m=d_sc_tf.b_tf_superconductor_critical_zero_temp_strain,
+                tc0m=d_sc_tf.temp_tf_superconductor_critical_zero_field_strain,
+                c0=1.0e10,
+                temp_tf_coolant_peak_field=self.data.tfcoil.tftmp,
+                data=self.data,
+            )
         )
 
         self.data.tfcoil.v_tf_coil_dump_quench_kv = (
@@ -4371,10 +4349,6 @@ def tf_croco_averaged_turn_geometry(
         # Area of inter-turn insulation: single turn [m²]
         a_tf_turn_insulation = a_tf_turn - dx_tf_turn_conduit_full_average**2
 
-        a_tf_turn_cable_space_no_void = copy.copy(
-            self.data.tfcoil.a_tf_turn_cable_space_no_void
-        )
-
         # Diameter of circular cable space inside conduit [m]
         dx_tf_turn_cable_space_average = (
             dx_tf_turn_conduit_full_average - 2.0e0 * dx_tf_turn_steel
@@ -4382,7 +4356,8 @@ def tf_croco_averaged_turn_geometry(
 
         # Cross-sectional area of conduit jacket per turn [m²]
         a_tf_turn_steel = (
-            dx_tf_turn_conduit_full_average**2 - a_tf_turn_cable_space_no_void
+            dx_tf_turn_conduit_full_average**2
+            - self.data.tfcoil.a_tf_turn_cable_space_no_void
         )
 
         return CROCOAveragedTurnGeometry(
@@ -4422,8 +4397,6 @@ def tf_croco_superconductor_properties(
             Operating current per turn (A)
         temp_tf_peak :
             Coil temperature at peak field point (K)
-        a_tf_turn_cable_space_effective :
-            Effective cross-sectional area of the TF turn cable space (m²)
         i_tf_superconductor :
             Integer identifier for the superconductor material model to use.
         dr_tf_hts_tape :
@@ -4436,12 +4409,17 @@ def tf_croco_superconductor_properties(
         Returns
         -------
         TFSuperconductorLimits
-             A dataclass containing the calculated superconducting properties of the TF coil, including:
+            A dataclass containing the calculated superconducting properties of the TF
+            coil, including:
             - j_tf_wp_critical: Critical current density in the TF winding pack (A/m²).
-            - j_superconductor_critical: Critical current density in the superconductor (A/m²).
-            - f_c_tf_turn_operating_critical: Ratio of operating current to critical current for the TF turn (dimensionless).
-            - j_tf_superconductor: Current density  in the superconductor at operating conditions (A/m²).
-            - j_tf_coil_turn: Current density in the TF coil turn at operating conditions (A/m²).
+            - j_superconductor_critical: Critical current density in the
+            superconductor (A/m²).
+            - f_c_tf_turn_operating_critical: Ratio of operating current to critical
+            current for the TF turn (dimensionless).
+            - j_tf_superconductor: Current density  in the superconductor at operating
+            conditions (A/m²).
+            - j_tf_coil_turn: Current density in the TF coil turn at operating
+            conditions (A/m²).
             - bc20m: Critical magnetic field at 20 K and zero strain (T).
             - tc0m: Critical temperature at zero magnetic field and zero strain (K).
             - c_turn_cables_critical: Critical current in the TF turn cables (A).
@@ -4852,21 +4830,21 @@ def output_croco_info(self) -> None:
             self.outfile,
             "Area of central copper bar (m²)",
             "(a_tf_turn_croco_copper_bar)",
-            self.data.superconducting_tfcoil.a_tf_turn_croco_copper_bar,
+            d_sc_tf.a_tf_turn_croco_copper_bar,
             "OP ",
         )
         po.ovarre(
             self.outfile,
             "Total copper area of conductor, total (m²)",
             "(a_tf_turn_croco_cable_space_copper)",
-            self.data.superconducting_tfcoil.a_tf_turn_croco_cable_space_copper,
+            d_sc_tf.a_tf_turn_croco_cable_space_copper,
             "OP ",
         )
         po.ovarre(
             self.outfile,
             "Hastelloy area of conductor (m²)",
             "(a_tf_turn_croco_hastelloy)",
-            self.data.superconducting_tfcoil.a_tf_turn_croco_hastelloy,
+            d_sc_tf.a_tf_turn_croco_hastelloy,
             "OP ",
         )
 

From c394af723bc7cc5d6131f46f01cdf6f2ac0cc319 Mon Sep 17 00:00:00 2001
From: Timothy Nunn <timothy.nunn@ukaea.uk>
Date: Thu, 6 Aug 2026 14:48:43 +0100
Subject: [PATCH 21/21] Fix line too long

---
 process/models/superconductors.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/process/models/superconductors.py b/process/models/superconductors.py
index d4e5c9f675..2590fd9b4c 100644
--- a/process/models/superconductors.py
+++ b/process/models/superconductors.py
@@ -835,8 +835,8 @@ def hijc_rebco(
             * (b_conductor / b_critical - 1) ** q
         )
 
-    # Critical current times HTS area: default area is width 4mm times HTS layer thickness 1 um,
-    # divided by the tape area to provide engineering Jc per tape,!
+    # Critical current times HTS area: default area is width 4mm times HTS layer
+    # thickness 1 um, divided by the tape area to provide engineering Jc per tape,!
     # A scaling factor of 0.4 used to be applied below to assume the difference
     # between tape stacks and CORC cable layouts.