GField module

Plugin-driven magnetic-field framework. More...

Collaboration diagram for GField module:

Topics
	GField examples
	Example programs demonstrating how to configure and use the GField module.
	GField ASCII-map factory
	Generic ASCII field-map plugin (dipole, cylindrical, phi-segmented, cartesian 3D).
	GField multipoles factory
	Multipole magnetic-field plugin implementation.

Namespaces
namespace	gfields

Data Structures
struct	GFieldDefinition
	Lightweight configuration carrier used to load and configure a GField plugin. More...
class	GField
	Abstract base class representing a magnetic field. More...
class	GMagneto
	Manager for magnetic fields and their associated G4FieldManager objects. More...
constexpr char	gfields::GFIELD_DEFAULT_INTEGRATION_STEPPER [] = "G4DormandPrince745"
	Default integration stepper name used when the requested stepper is unsupported.
constexpr char	gfields::GFIELD_DEFAULT_MINIMUM_STEP [] = "1.0*mm"
	Default minimum step for the chord finder (string with Geant4 units).
constexpr char	gfields::GFIELD_DEFAULT_MAXIMUM_STEP [] = "0*mm"
	Default maximum acceptable field step for Geant4 propagation.
constexpr char	gfields::GFIELD_DEFAULT_VERTEX [] = "0*mm"
	Default origin coordinate component for multipole fields (string with Geant4 units).
constexpr char	gfields::GFIELD_DEFAULT_ROTANGLE [] = "0*deg"
	Default multipole roll rotation angle (string with Geant4 units).
constexpr char	gfields::GFIELD_DEFAULT_VERBOSITY [] = "0"
	Default verbosity level (string) for field-related configuration.
constexpr char	gfields::GLOBAL_FIELD_OPTION [] = "global_field"
	Command-line option name used to associate a field with the ROOT world volume.
constexpr char	gfields::NO_FIELD_OPTION [] = "no_field"
	Command-line option name used to reset (remove) field associations.
constexpr char	gfields::MAX_FIELD_STEP_OPTION [] = "max_field_step"
	Command-line option name used to set the global maximum acceptable field step.
constexpr char	gfields::NO_FIELD_ALL [] = "all"
	Special gfields::NO_FIELD_OPTION value that resets all fields, including gfields::GLOBAL_FIELD_OPTION.
constexpr int	gfields::ERR_WRONG_FIELD_ROTATION = 1201
constexpr int	gfields::ERR_WRONG_FIELD_NOT_FOUND = 1202
constexpr int	gfields::ERR_STEPPER_NOT_FOUND = 1203
constexpr int	gfields::ERR_WRONG_POLE_NUMBER = 1204
constexpr int	gfields::ERR_WRONG_FIELD_SYMMETRY = 1205
constexpr int	gfields::ERR_WRONG_COORDINATE_DEF = 1206
constexpr int	gfields::ERR_MAP_FILE_NOT_FOUND = 1207

Detailed Description

The module provides:

• A common abstract interface for magnetic fields (GField),
• A lightweight configuration carrier (GFieldDefinition),
• A manager that loads plugins and builds G4FieldManager instances (GMagneto),
• Option definitions for fields implemented in this module (namespace gfields).

The actual magnetic-field behavior is implemented in plugins (shared libraries) that expose a C factory symbol (see instantiate()).

Variable Documentation

ERR_MAP_FILE_NOT_FOUND

int gfields::ERR_MAP_FILE_NOT_FOUND = 1207

inlineconstexpr

Definition at line 90 of file gfieldConventions.h.

ERR_STEPPER_NOT_FOUND

int gfields::ERR_STEPPER_NOT_FOUND = 1203

inlineconstexpr

Definition at line 86 of file gfieldConventions.h.

ERR_WRONG_COORDINATE_DEF

int gfields::ERR_WRONG_COORDINATE_DEF = 1206

inlineconstexpr

Definition at line 89 of file gfieldConventions.h.

ERR_WRONG_FIELD_NOT_FOUND

int gfields::ERR_WRONG_FIELD_NOT_FOUND = 1202

inlineconstexpr

Definition at line 85 of file gfieldConventions.h.

ERR_WRONG_FIELD_ROTATION

int gfields::ERR_WRONG_FIELD_ROTATION = 1201

inlineconstexpr

Definition at line 84 of file gfieldConventions.h.

ERR_WRONG_FIELD_SYMMETRY

int gfields::ERR_WRONG_FIELD_SYMMETRY = 1205

inlineconstexpr

Definition at line 88 of file gfieldConventions.h.

ERR_WRONG_POLE_NUMBER

int gfields::ERR_WRONG_POLE_NUMBER = 1204

inlineconstexpr

Definition at line 87 of file gfieldConventions.h.

GFIELD_DEFAULT_INTEGRATION_STEPPER

char gfields::GFIELD_DEFAULT_INTEGRATION_STEPPER[] = "G4DormandPrince745"

inlineconstexpr

This is a Geant4 stepper class name expressed as a string.

Definition at line 15 of file gfieldConventions.h.

GFIELD_DEFAULT_MAXIMUM_STEP

char gfields::GFIELD_DEFAULT_MAXIMUM_STEP[] = "0*mm"

inlineconstexpr

A value less than or equal to zero leaves the Geant4 propagator default unchanged.

Definition at line 29 of file gfieldConventions.h.

GFIELD_DEFAULT_MINIMUM_STEP

char gfields::GFIELD_DEFAULT_MINIMUM_STEP[] = "1.0*mm"

inlineconstexpr

This value is stored as a string to preserve unit expressions and is parsed later.

Definition at line 22 of file gfieldConventions.h.

GFIELD_DEFAULT_ROTANGLE

char gfields::GFIELD_DEFAULT_ROTANGLE[] = "0*deg"

inlineconstexpr

Definition at line 41 of file gfieldConventions.h.

GFIELD_DEFAULT_VERBOSITY

char gfields::GFIELD_DEFAULT_VERBOSITY[] = "0"

inlineconstexpr

Definition at line 46 of file gfieldConventions.h.

GFIELD_DEFAULT_VERTEX

char gfields::GFIELD_DEFAULT_VERTEX[] = "0*mm"

inlineconstexpr

Definition at line 36 of file gfieldConventions.h.

GLOBAL_FIELD_OPTION

char gfields::GLOBAL_FIELD_OPTION[] = "global_field"

inlineconstexpr

The value is the name of a configured field (see gmultipoles / gfields). The corresponding G4FieldManager is installed on the ROOT world volume and propagated to all daughters, acting as a global field wherever a more specific per-volume field is not set.

Definition at line 55 of file gfieldConventions.h.

MAX_FIELD_STEP_OPTION

char gfields::MAX_FIELD_STEP_OPTION[] = "max_field_step"

inlineconstexpr

The value is parsed as a Geant4 length and passed to G4PropagatorInField::SetLargestAcceptableStep() when positive. This controls the largest field propagation step accepted by Geant4 transportation.

Definition at line 74 of file gfieldConventions.h.

NO_FIELD_ALL

char gfields::NO_FIELD_ALL[] = "all"

inlineconstexpr

Definition at line 80 of file gfieldConventions.h.

NO_FIELD_OPTION

char gfields::NO_FIELD_OPTION[] = "no_field"

inlineconstexpr

The value is either a single gvolume name, a whitespace/comma-separated list of gvolume names, or the special value gfields::NO_FIELD_ALL. A listed volume that was associated with a field has that association removed; gfields::NO_FIELD_ALL removes every per-volume field as well as the gfields::GLOBAL_FIELD_OPTION. Fields that end up unused as a result are never loaded (their plugins and maps are skipped).

Definition at line 66 of file gfieldConventions.h.