Class DiffusionSDE

Defined in File DiffusionSDE.h

Inheritance Relationships

Base Type

public Module (Class Module)

Class Documentation

class DiffusionSDE : public Module 

Propagates candidates as pseudo(!)-particles. The time integration of SDEs is used to solve the transport equation. Here an Euler-Mayurama integration scheme is used. The diffusion tensor can be anisotropic with respect to the magnetic field line coordinates. The integration of field lines is done via the CK-algorithm.

Public Functions

DiffusionSDE(ref_ptr<crpropa::MagneticField> magneticField, double tolerance = 1e-4, double minStep = 10 * pc, double maxStep = 1 * kpc, double epsilon = 0.1)

Constructor

Parameters:

magneticField – the magnetic field to be used
tolerance – Tolerance is criterion for step adjustment. Step adjustment takes place when the tangential vector of the magnetic field line is calculated.
minStep – minStep/c_light is the minimum integration time step
maxStep – maxStep/c_light is the maximum integration time step
epsilon – Ratio of parallel and perpendicular diffusion coefficient D_par = epsilon*D_perp

DiffusionSDE(ref_ptr<crpropa::MagneticField> magneticField, ref_ptr<crpropa::AdvectionField> advectionField, double tolerance = 1e-4, double minStep = 10 * pc, double maxStep = 1 * kpc, double epsilon = 0.1)

Constructor

Parameters:

magneticField – the magnetic field to be used
advectionField – object containing advection field
tolerance – Tolerance is criterion for step adjustment. Step adjustment takes place when the tangential vector of the magnetic field line is calculated.
minStep – minStep/c_light is the minimum integration time step
maxStep – maxStep/c_light is the maximum integration time step
epsilon – Ratio of parallel and perpendicular diffusion coefficient D_par = epsilon*D_perp

virtual void process(crpropa::Candidate *candidate) const

void tryStep(const Vector3d &Pos, Vector3d &POut, Vector3d &PosErr, double z, double propStep) const

void driftStep(const Vector3d &Pos, Vector3d &LinProp, double h) const

void calculateBTensor(double rig, double BTen[], Vector3d pos, Vector3d dir, double z) const

void setMinimumStep(double minStep)

void setMaximumStep(double maxStep)

void setTolerance(double tolerance)

void setEpsilon(double kappa)

void setAlpha(double alpha)

void setScale(double Scale)

void setMagneticField(ref_ptr<crpropa::MagneticField> magneticField)

void setAdvectionField(ref_ptr<crpropa::AdvectionField> advectionField)

double getMinimumStep() const

double getMaximumStep() const

double getTolerance() const

double getEpsilon() const

double getAlpha() const

double getScale() const

virtual std::string getDescription() const

ref_ptr<MagneticField> getMagneticField() const

Vector3d getMagneticFieldAtPosition(Vector3d pos, double z) const

get magnetic field vector at current candidate position

Parameters:

pos – current position of the candidate
z – current redshift is needed to calculate the magnetic field

Returns:

magnetic field vector at the position pos

ref_ptr<AdvectionField> getAdvectionField() const

Vector3d getAdvectionFieldAtPosition(Vector3d pos) const

get advection field vector at current candidate position

Parameters:: pos – current position of the candidate
Returns:: magnetic field vector at the position pos

void setDescription(const std::string &description)

inline void process(ref_ptr<Candidate> candidate) const

inline size_t addReference() const

inline size_t removeReference() const

inline int removeReferenceNoDelete() const

inline size_t getReferenceCount() const

Protected Attributes

mutable size_t _referenceCount