Exact helix through pure dipole field. More...

#include <BDSIntegratorDipoleRodrigues2.hh>

Inheritance diagram for BDSIntegratorDipoleRodrigues2:

Collaboration diagram for BDSIntegratorDipoleRodrigues2:

Public Member Functions
	BDSIntegratorDipoleRodrigues2 (G4Mag_EqRhs *eqOfMIn, G4double minimumRadiusOfCurvature)

virtual void	DumbStepper (const G4double yIn[6], G4ThreeVector field, G4double stepLength, G4double yOut[6])

void	SingleStep (const G4double yIn[6], const G4double &h, G4double yOut[6])

virtual void	Stepper (const G4double yIn[6], const G4double dydx[], G4double h, G4double yOut[6], G4double yErr[6])
	Output error array.

virtual G4int	IntegratorOrder () const

void	AdvanceHelixForSpiralling (const G4double yIn[6], const G4ThreeVector &field, const G4double &h, G4double yOut[6], G4double yErr[6])

G4double	RadiusOfHelix () const
	Public accessor for protected variable in base class.

Public Member Functions inherited from BDSIntegratorDrift
void	AdvanceDriftMag (const G4double yIn[], const G4double h, G4double yOut[], G4double yErr[]) const
	Error array [6] all 0.

void	AdvanceDriftMag (const G4double yIn[], const G4ThreeVector &unitMomentum, const G4double h, G4double yOut[], G4double yErr[]) const

Protected Member Functions
void	FudgeDistChordToZero ()

Protected Attributes
G4Mag_EqRhs *	eqOfM
	Cache of equation of motion. This class does not own it.

Private Member Functions
	BDSIntegratorDipoleRodrigues2 ()=delete
	Private default constructor to force use of provided one.

Private Attributes
G4double	minimumRadiusOfCurvature

Detailed Description

Exact helix through pure dipole field.

Integrator based on G4MagHelicalStepper that provides required tracking througha pure magnetic field, but is a pure virtual class.

This class implements the required Stepper method that uses the provided AdvanceHelix method from the base class.

Unlike other BDSIM integrators this works in global coordinates and does not require the transforms to curvilinear coordinates.

For low momentum particles (|p| < 40 MeV) we use the G4ClassicalRK4 integrator instead of the one for the pure magnetic field as it is more robust.

Note, some things that could be passed by reference are not purely for correct overload of Geant4 function.

Author: Laurie Nevay

Definition at line 53 of file BDSIntegratorDipoleRodrigues2.hh.

Constructor & Destructor Documentation

◆ BDSIntegratorDipoleRodrigues2()

BDSIntegratorDipoleRodrigues2::BDSIntegratorDipoleRodrigues2	(	G4Mag_EqRhs *	eqOfMIn,
		G4double	minimumRadiusOfCurvature
	)

Definition at line 32 of file BDSIntegratorDipoleRodrigues2.cc.

◆ ~BDSIntegratorDipoleRodrigues2()

virtual BDSIntegratorDipoleRodrigues2::~BDSIntegratorDipoleRodrigues2 ( )

inlinevirtual

Definition at line 59 of file BDSIntegratorDipoleRodrigues2.hh.

Member Function Documentation

◆ AdvanceHelixForSpiralling()

void BDSIntegratorDipoleRodrigues2::AdvanceHelixForSpiralling	(	const G4double	yIn[6],
		const G4ThreeVector &	field,
		const G4double &	h,
		G4double	yOut[6],
		G4double	yErr[6]
	)

Variation of AdvanceHelix specifically to deal with particles that are likely to be spiralling in the magnetic field.

Definition at line 156 of file BDSIntegratorDipoleRodrigues2.cc.

References BDSIntegratorDrift::AdvanceDriftMag(), FudgeDistChordToZero(), and BDS::IsFinite().

Referenced by Stepper().

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◆ DumbStepper()

void BDSIntegratorDipoleRodrigues2::DumbStepper	(	const G4double	yIn[6],
		G4ThreeVector	field,
		G4double	stepLength,
		G4double	yOut[6]
	)

virtual

Required to be provided by base class, but apparently should never be called by the driver. Simply calls AdvanceHelix.

Definition at line 39 of file BDSIntegratorDipoleRodrigues2.cc.

◆ FudgeDistChordToZero()

void BDSIntegratorDipoleRodrigues2::FudgeDistChordToZero ( )

protected

DistChord() is non-virtual function in base class so set Ang and RadHelix appropriately such that DistChord() will return 0.

Definition at line 196 of file BDSIntegratorDipoleRodrigues2.cc.

Referenced by AdvanceHelixForSpiralling(), BDSIntegratorDipoleFringe::BaseStepper(), and Stepper().

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◆ IntegratorOrder()

virtual G4int BDSIntegratorDipoleRodrigues2::IntegratorOrder ( ) const

inlinevirtual

Definition at line 84 of file BDSIntegratorDipoleRodrigues2.hh.

◆ RadiusOfHelix()

G4double BDSIntegratorDipoleRodrigues2::RadiusOfHelix ( ) const

inline

Public accessor for protected variable in base class.

Definition at line 95 of file BDSIntegratorDipoleRodrigues2.hh.

Referenced by BDSIntegratorDipoleQuadrupole::Stepper().

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◆ SingleStep()

void BDSIntegratorDipoleRodrigues2::SingleStep	(	const G4double	yIn[6],
		const G4double &	h,
		G4double	yOut[6]
	)

Perform a single step. Useful for other integrators that want to use this one to estimate the radius of curvature in the field, in which case, no need for usual two step calculation, nor error calculation.

Definition at line 47 of file BDSIntegratorDipoleRodrigues2.cc.

References eqOfM.

Referenced by BDSIntegratorDipoleQuadrupole::Stepper().

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◆ Stepper()

void BDSIntegratorDipoleRodrigues2::Stepper	(	const G4double	yIn[6],
		const G4double	dydx[],
		G4double	h,
		G4double	yOut[6],
		G4double	yErr[6]
	)

virtual

Output error array.

Calculate output coordinates. Decide if particle is spiralling or not. Nominally calculate two half steps and compare to one full step for error estimation.

Parameters