Seth R. Johnson

@whokion Is this the physics implemented by NEST, which is used by LZ (https://github.com/celeritas-project/celeritas/issues/1345#issue-2440476235)?

Related: might be fixed by improved navigation with #2111

@hhollenb I think that's a great idea, and do you think it could wait until we have the basic surface crossing "working" (or at least to a point where it...

Fair enough! I think we could make this work really easily by putting a `bool debug_physics{false};` into the surface physics list, which should be excluded with the others, and then...

@mrguilima This is ready for review.

Ugh, bad news: as of this commit, vecgeom 2 fails with config: ```json {"_category":"system","_label":"build","config":{"build_type":"relwithdebinfo,shared","core_geo":"VecGeom","core_rng":"xorwow","debug":true,"geant4":"global-dynamic,multithreaded,shared,gdml","gpu_architectures":"90","hostname":"hudson","openmp":"disabled","real_type":"double","units":"CGS","use":["covfie","cuda","geant4","hepmc3","root","vecgeom"],"vecgeom":"bvh_single,tuple,Scalar","versions":{"CLHEP":"2.4.7.1","CUDA":"12.9.86","G4VG":"1.0.5","Geant4":"11.3.2","HepMC3":"3.03.01","ROOT":"6.36.04","Thrust":"","VecGeom":"2.0.0-dev.7","covfie":"0.15.3"}},"version":"0.7.0-dev.204+71736034a"} ``` before: ``` The following tests FAILED: 232 - celeritas/geo/Geometry:SimpleCms* (Failed) gpu unit 234 - celeritas/geo/Geometry:ThreeSpheres*...

@amandalund Would you be able to give me any feedback on this and hit merge if you think it's ok?

Thanks @amandalund , I've also removed the `Data` part of the class names from the params/state template classes, since we should be more consistent about using Data exclusively for collection...

I realize I need to update archspec-json first (similar to archspec/archspec-json#141 ). But the latest stable xcode clang `Apple clang version 17.0.0 (clang-1700.3.19.1)` may not have the right microarch flags...

Proposed steps: - Make a G4 example with optical physics; figure out how to cleanly replace the cerenkov/scintillatoin with Celeritas (custom modular physics list?) - Add adapter classes for Geant4...