orb5x::BackgroundModule Class Reference

Initializes equilibrium distribution functions used by marker loading and pushing. More...

#include "background.hpp"

Static Public Member Functions
static void	get_background_flow (Real s, Real chi, Real phi, Real &vpar, Real &vperp)
	Query equilibrium parallel and perpendicular flow.
static Real	get_background_potential (Real s, Real chi, Real phi)
	Query the equilibrium electrostatic potential.
static Real	get_KE (Real ut, Real mu, Real b)
	Convert parallel velocity and magnetic moment to kinetic energy.
static Real	get_mu (Real ut, Real ze, Real b)
	Recover magnetic moment from energy and parallel velocity.
static Real	get_uabs (Real mu, Real ze, Real b)
	Recover the magnitude of parallel velocity from invariants.
static void	init_background ()
	Initialize all species background distributions and emit the f0 dump.
static void	load_background_fields (const std::string &fname)
	Validate a tabulated background-distribution HDF5 file.
static Real	vf0_local_maxwellian (Real vth2, Real nval, Real ze)
	Evaluate an isotropic local Maxwellian.

Detailed Description

Initializes equilibrium distribution functions used by marker loading and pushing.

This facade implements the background-distribution stage of ORB5X: it initializes analytic or tabulated \(f_0\) data for every species, supplies normalized velocity-coordinate identities, and writes the reference distribution diagnostics. Equilibrium density, temperature, magnetic-field, and flow profiles are obtained from Equil; marker operations consume the resulting SpeciesVariables state through ParticleModule.

Member Function Documentation

get_background_flow()

void orb5x::BackgroundModule::get_background_flow ( Real s, Real chi, Real phi, Real & vpar, Real & vperp )

static

Query equilibrium parallel and perpendicular flow.

Parameters

[in]	s	Normalized radial coordinate.
[in]	chi	Poloidal angle [rad].
[in]	phi	Toroidal angle [rad].
[out]	vpar	Normalized parallel flow; currently set to zero.
[out]	vperp	Normalized perpendicular flow; currently set to zero.

Note

This compatibility entry point is presently a stub, not Equil::profiles.

get_background_potential()

Real orb5x::BackgroundModule::get_background_potential ( Real s, Real chi, Real phi )

static

Query the equilibrium electrostatic potential.

Parameters

[in]	s	Normalized radial coordinate.
[in]	chi	Poloidal angle [rad].
[in]	phi	Toroidal angle [rad].

Returns

Currently zero; spatial background-potential interpolation is not implemented.

get_KE()

Real orb5x::BackgroundModule::get_KE ( Real ut, Real mu, Real b )

static

Convert parallel velocity and magnetic moment to kinetic energy.

Parameters

[in]	ut	Normalized parallel velocity.
[in]	mu	Normalized magnetic moment per unit mass.
[in]	b	Normalized magnetic-field magnitude.

Returns

\(u_\parallel^2/2+\mu B\) in normalized energy-per-mass units.

get_mu()

Real orb5x::BackgroundModule::get_mu ( Real ut, Real ze, Real b )

static

Recover magnetic moment from energy and parallel velocity.

Parameters

[in]	ut	Normalized parallel velocity.
[in]	ze	Normalized kinetic energy per unit mass.
[in]	b	Normalized magnetic-field magnitude.

Returns

\((\mathcal{E}-u_\parallel^2/2)/B\), or zero when B is singular.

get_uabs()

Real orb5x::BackgroundModule::get_uabs ( Real mu, Real ze, Real b )

static

Recover the magnitude of parallel velocity from invariants.

Parameters

[in]	mu	Normalized magnetic moment per unit mass.
[in]	ze	Normalized kinetic energy per unit mass.
[in]	b	Normalized magnetic-field magnitude.

Returns

\(\sqrt{2(\mathcal{E}-\mu B)}\), clipped to zero outside its domain.

init_background()

void orb5x::BackgroundModule::init_background ( )

static

Initialize all species background distributions and emit the f0 dump.

load_background_fields()

void orb5x::BackgroundModule::load_background_fields ( const std::string & fname )

static

Validate a tabulated background-distribution HDF5 file.

Parameters

[in]

fname

Path containing /f0/psi, /f0/u, and /f0/ze datasets.

Exceptions

std::runtime_error

if the path or required HDF5 objects are absent.

vf0_local_maxwellian()

Real orb5x::BackgroundModule::vf0_local_maxwellian ( Real vth2, Real nval, Real ze )

static

Evaluate an isotropic local Maxwellian.

Parameters

[in]	vth2	Squared normalized thermal speed \(v_{th}^2\).
[in]	nval	Local normalized density.
[in]	ze	Normalized kinetic energy per unit mass.

Returns

\(n(2\pi v_{th}^2)^{-3/2}\exp(-\mathcal{E}/v_{th}^2)\), or zero for non-positive density or thermal speed.

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The documentation for this class was generated from the following file:

• background.hpp