Cyclotron radiation source based on Albajar scaling.

Total cyclotron radiation is from: F. Albajar et al 2001 Nucl. Fusion 41 665
https://doi.org/10.1088/0029-5515/41/6/301

Radial profile of the cyclotron radiation is from: J.F. Artaud et al 2018 Nucl. Fusion 58 105001
https://doi.org/10.1088/1741-4326/aad5b1

The Albajar scaling includes solving a parameterization for electron density and temperature profiles. For computational efficiency this is done here with a combination of a closed form analytical solution, and a 1D grid search.

PiperOrigin-RevId: 707885918

torax/geometry/geometry.py

@@ -152,6 +152,7 @@ class Geometry:
   spr_cell: chex.Array
   spr_face: chex.Array
   delta_face: chex.Array
+  elongation: chex.Array
   elongation_face: chex.Array
   g0: chex.Array
   g0_face: chex.Array
@@ -273,6 +274,7 @@ class GeometryProvider:
   spr_cell: interpolated_param.InterpolatedVarSingleAxis
   spr_face: interpolated_param.InterpolatedVarSingleAxis
   delta_face: interpolated_param.InterpolatedVarSingleAxis
+  elongation: interpolated_param.InterpolatedVarSingleAxis
   elongation_face: interpolated_param.InterpolatedVarSingleAxis
   g0: interpolated_param.InterpolatedVarSingleAxis
   g0_face: interpolated_param.InterpolatedVarSingleAxis
@@ -416,6 +418,7 @@ class StandardGeometryProvider(GeometryProvider):
   jtot_face: interpolated_param.InterpolatedVarSingleAxis
   delta_upper_face: interpolated_param.InterpolatedVarSingleAxis
   delta_lower_face: interpolated_param.InterpolatedVarSingleAxis
+  elongation: interpolated_param.InterpolatedVarSingleAxis
   elongation_face: interpolated_param.InterpolatedVarSingleAxis
 
   @functools.partial(jax_utils.jit, static_argnums=0)
@@ -636,6 +639,7 @@ def build_circular_geometry(
       Rout=Rout,
       Rout_face=Rout_face,
       # Set the circular geometry-specific params.
+      elongation=elongation,
       elongation_face=elongation_face,
       volume_hires=volume_hires,
       area_hires=area_hires,
@@ -1528,6 +1532,9 @@ def build_standard_geometry(
   delta_face = 0.5 * (delta_upper_face + delta_lower_face)
 
   # elongation
+  elongation = rhon_interpolation_func(
+      rho_norm, intermediate.elongation
+  )
   elongation_face = rhon_interpolation_func(
       rho_face_norm, intermediate.elongation
   )
@@ -1628,6 +1635,7 @@ def build_standard_geometry(
       jtot_face=jtot_face,
       delta_upper_face=delta_upper_face,
       delta_lower_face=delta_lower_face,
+      elongation=elongation,
       elongation_face=elongation_face,
       volume_hires=volume_hires,
       area_hires=area_hires,