scotty.ray_solver#

Functions for evolving a single ray

Used by the main code to find the point where the beam leaves the plasma, which then sets the integration limits for the beam solver.

class scotty.ray_solver.K_cutoff_data(q_R, q_Z, K_norm_min, poloidal_flux, theta_m)#

Bases: object

Properties of \(K\)-cutoff

Parameters
Return type

None

scotty.ray_solver.handle_leaving_plasma_events(tau_events, ray_parameters_2D_events)#

Handle events detected by scipy.integrate.solve_ivp. This only handles events due to the ray leaving the plasma or simulation:

  • "leave_plasma": the ray has left the plasma

  • "leave_LCFS": the ray has left the last-closed flux surface. For most simulations, this is likely identical to leaving the plasma

  • "leave_simulation": the ray has left the simulated area (essentially the bounding box of the plasma)

  • "cross_resonance": the ray has crossed a resonance

Parameters

  • tau_events (Dict[str, FloatArray]) – A mapping between event names and the solver t_events

  • K_R_LCFS (float) – The radial wavevector in the case where the beam has crossed the LCFS

  • ray_parameters_2D_events (numpy.ndarray[Any, numpy.dtype[numpy.float64]]) –

Returns

The value of tau when the detected event first occurred

Return type

FloatArray

scotty.ray_solver.handle_no_resonance(solver_ray_output, tau_leave, tau_points, K_zeta, solver_arguments, event_leave_plasma)#

Add an additional tau point at the cut-off (minimum K) if the beam does NOT reach a resonance

Propagates another ray to find the cut-off location

Parameters
Return type

numpy.ndarray[Any, numpy.dtype[numpy.float64]]

scotty.ray_solver.make_solver_events(poloidal_flux_enter, launch_angular_frequency, field)#

Define event handlers for the ray solver

Only works correctly for the 2D case

Parameters

  • poloidal_flux_enter (float) – Poloidal flux label of plasma surface

  • launch_angular_frequency (float) – Beam frequency

  • field (MagneticField) – Magnetic field object

Returns

Dictionary of event handlers with names

Return type

Dict[str, Callable]

scotty.ray_solver.propagate_ray(poloidal_flux_enter, launch_angular_frequency, field, initial_position, K_initial, hamiltonian, rtol, atol, quick_run, len_tau, tau_max=100000.0, verbose=True)#

Propagate a ray. Quickly finds tau at which the ray leaves the plasma, as well as estimates location of cut-off.

Parameters

  • poloidal_flux_enter (float) – Flux label where ray enters plasma

  • launch_angular_frequency (float) – Angular frequency of beam

  • field (MagneticField) – Object describing magnetic field

  • initial_position (FloatArray) – Initial position in q coordinates

  • K_initial (FloatArray) – Initial wavevector

  • hamiltonian (Hamiltonian) – Object to compute Hamiltonian

  • rtol (float) – Relative tolerance

  • atol (float) – Absolute tolerance

  • quick_run (bool) – If true, use minimum of \(|K|\) to estimate cut-off location

  • len_tau (int) – Number of points for tau

  • tau_max (float) – Maximum value of tau before the solver stops

  • verbose (bool) – If true, print some timing information

Returns

Returns either: value of tau where ray left plasma, along with an array of tau points for the beam solver to output results at; or, a K_cutoff_data with information about the estimated location of the cut-off

Return type

Union[Tuple[float, FloatArray], K_cutoff_data]

scotty.ray_solver.quick_K_cutoff(ray_parameters_turning_pt, K_zeta, field)#

Calculate some quantities at the minimum \(|K|\) along the ray

Parameters

  • ray_parameters_turning_pt (FloatArray) – State vector from ray evolution

  • K_zeta (float) – \(K_\zeta\) for the ray

  • field (MagneticField) – Object describing the magnetic field

Returns

Ray coordinates, \(|K|\), magnetic flux, and mismatch angle

Return type

q_R, q_Z, K_norm, poloidal_flux, theta_m

scotty.ray_solver.ray_evolution_2D_fun(tau, ray_parameters_2D, K_zeta, hamiltonian)#
Parameters
Returns

d (beam_parameters) / d tau

Return type

d_beam_parameters_d_tau

Notes