Restrict tf turn to correct supercon

[chris-ashe]

This pull request makes several important changes to how the TF (Toroidal Field) coil conductor geometry and materials are represented and handled throughout the codebase. The main focus is on renaming and clarifying variable names related to conductor dimensions, expanding the data model for CroCo conductor materials, and updating tests and input files to match the new conventions.

Summary of most important changes:

Variable Renaming and Data Model Updates

• Replaced ambiguous variables like t_conductor, t_conductor_radial, and t_conductor_toroidal with more descriptive names such as dx_tf_turn_conduit_full_average, dr_tf_turn_conduit_full, and dx_tf_turn_conduit_full_toroidal throughout the codebase, improving clarity and consistency.

• Expanded the SuperconductingTFData class to include additional fields for CroCo cable geometry and material fractions (copper, superconductor, Hastelloy, helium, solder, jacket, REBCO), and clarified their units and meanings.

Plotting and Output Improvements

• Added new output fields to summary plots for the TF coil, specifically the field at the conductor and the superconductor critical current density at operating conditions, making plots more informative.

Physics Model Clarification

• Clarified the calculation in hijc_rebco to explicitly refer to "critical current" instead of "critical current density," improving the accuracy of the documentation and variable naming.

Test and Input File Updates

• Updated regression and unit test input files and test code to use the new variable names and ensure consistency with the main code changes.

Variable Mapping

• Updated the obsolete variable mapping in obsolete_vars.py to reflect the new conductor width variable name.

These changes improve code clarity, maintainability, and the accuracy of physical modeling and output.

Checklist

I confirm that I have completed the following checks:

• My changes follow the PROCESS style guide
• I have justified any large differences in the regression tests caused by this pull request in the comments.
• I have added new tests where appropriate for the changes I have made.
• If I have had to change any existing unit or integration tests, I have justified this change in the pull request comments.
• If I have made documentation changes, I have checked they render correctly.
• I have added documentation for my change, if appropriate.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 37.56345% with 123 lines in your changes missing coverage. Please review.
✅ Project coverage is 48.75%. Comparing base (0d00ff1) to head (6c67923).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
process/models/tfcoil/superconducting.py	30.28%	122 Missing ⚠️
process/models/superconductors.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4309      +/-   ##
==========================================
- Coverage   48.79%   48.75%   -0.04%     
==========================================
  Files         151      151              
  Lines       29339    29334       -5     
==========================================
- Hits        14315    14301      -14     
- Misses      15024    15033       +9     

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[timothy-nunn]

Please could you also get a modeler to check this over too

[timothy-nunn]

I am quite against changing the regression test setup (e.g. by changing the coil technology being used) as this will render the tracker useless. I would much rather you introduce another test (could be just an eval IN.DAT) that checks the CroCo coil (and possibly also tests some of our as-yet untested models)

[chris-ashe]

A discussion needs to be done about this as for st_regression the current configuration is an impossible design of tape conductors in a cable format. So the current regression is physically wrong. Will look at adding other CroCo tests

[timothy-nunn]

See previous comment.