Guiding Center Particle Tracing

CHANGELOG.md

@@ -3,6 +3,16 @@ Changelog
 
 New Features
 
+- Adds particle tracing capabilities in ``desc.particles`` module.
+    - Particle tracing is done via ``desc.particles.trace_particles`` function.
+    - Particles can be initialized in couple different ways:
+        - ``ManualParticleInitializerLab`` : Initializes particles at given positions in lab coordinates.
+        - ``ManualParticleInitializerFlux`` : Initializes particles at given positions in flux coordinates.
+        - ``CurveParticleInitializer`` : Initializes N particles on a given curve.
+        - ``SurfaceParticleInitializer`` : Initializes N particles on a given surface.
+    - Implemented particle trajectory models are:
+        - ``VacuumGuidingCenterTrajectory`` : Integrates the particle motion by vacuum guiding center ODEs, conserving energy and mu.
+    - Particle trajectories can be plotted with ``desc.plotting.plot_particle_trajectories`` function.
 - Adds new option for ``loss_function``, ``"sum"``, which changes an objective to target the sum of the values computed.
 - Adds ``"scipy-l-bfgs-b"`` optimizer option as a wrapper to scipy's ``"l-bfgs-b"`` method.
 

desc/__init__.py

@@ -30,6 +30,7 @@
     "magnetic_fields",
     "objectives",
     "optimize",
+    "particles",
     "perturbations",
     "plotting",
     "profiles",

desc/magnetic_fields/_core.py

@@ -831,6 +831,8 @@ def compute_magnetic_field(
         coords = jnp.atleast_2d(jnp.asarray(coords))
         if params is None:
             params = self.params
+        elif isinstance(params, dict):
+            params = params["params"]
         if basis == "xyz":
             coords = xyz2rpz(coords)