#include <acts/blob/sPHENIX/Core/include/Acts/MagneticField/SolenoidBField.hpp>

Collaboration diagram for Acts::SolenoidBField:

Classes
struct	Cache

struct	Config
	Config struct for the SolenoidBfield. More...

Public Member Functions
	SolenoidBField (Config config)
	the constructur with a shared pointer

Vector3D	getField (const Vector3D &position) const
	retrieve magnetic field value

Vector3D	getField (const Vector3D &position, Cache &) const
	Retrieve magnetic field value.

Vector2D	getField (const Vector2D &position) const
	Retrieve magnetic field value in local (r,z) coordinates.

Vector3D	getFieldGradient (const Vector3D &position, ActsMatrixD< 3, 3 > &) const
	retrieve magnetic field value & its gradient

Vector3D	getFieldGradient (const Vector3D &position, ActsMatrixD< 3, 3 > &, Cache &) const
	retrieve magnetic field value & its gradient

Private Member Functions
Vector2D	multiCoilField (const Vector2D &pos, double scale) const

Vector2D	singleCoilField (const Vector2D &pos, double scale) const

double	B_r (const Vector2D &pos, double scale) const

double	B_z (const Vector2D &pos, double scale) const

double	k2 (double r, double z) const

Private Attributes
Config	m_cfg

double	m_scale

double	m_dz

double	m_R2

Detailed Description

Implements a multi-coil solenoid magnetic field. On every call, the field is evaluated at that exact position. The field has radially symmetry, the field vectors point in +z direction. The config exposes a target field value in the center. This value is used to empirically determine a scale factor which reproduces this field value in the center.

E_1(k^2) = complete elliptic integral of the 1st kind E_2(k^2) = complete elliptic integral of the 2nd kind

E_1(k^2) and E_2(k^2) are usually indicated as K(k^2) and E(k^2) in literature, respectively _ 2 / pi / 2 2 2 - 1 / 2 E (k ) = | ( 1 - k sin {theta} ) dtheta 1 _/ 0

        _          ____________________

2 / pi / 2| / 2 2 E (k ) = | |/ 1 - k sin {theta} dtheta 2 _/ 0

k^2 = is a function of the point (r, z) and of the radius of the coil R

2 4Rr k = ------------— 2 2 (R + r) + z Using these, you can evaluate the two components B_r and B_z of the magnetic field: _ _ mu I | / 2 \ | 0 kz | |2 - k | 2 2 | B (r, z) = --— ---— | |----—|E (k ) - E (k ) | r 4pi ___ | | 2| 2 1 | | / 3 |_ \2 - 2k / _| |/ Rr

 _                                       _

mu I | / 2 \ | 0 k | | (R + r)k - 2r | 2 2 | B (r,z) = --— -— | | -----------— | E (k ) + E (k ) | z 4pi __ | | 2 | 2 1 | |/Rr |_ \ 2r(1 - k ) / _|

Definition at line 65 of file SolenoidBField.hpp.

View newest version in sPHENIX GitHub at line 65 of file SolenoidBField.hpp

Constructor & Destructor Documentation

Acts::SolenoidBField::SolenoidBField ( Config config )

the constructur with a shared pointer

Note: since it is a shared field, we enforce it to be const

Template Parameters

bField is the shared BField to be stored

Definition at line 16 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 16 of file SolenoidBField.cpp

References Acts::SolenoidBField::Config::bMagCenter, Acts::SolenoidBField::Config::length, m_cfg, m_dz, m_R2, m_scale, multiCoilField(), Acts::SolenoidBField::Config::nCoils, and Acts::SolenoidBField::Config::radius.

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Member Function Documentation

double Acts::SolenoidBField::B_r	(	const Vector2D &	pos,
		double	scale
	)		const

private

Definition at line 78 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 78 of file SolenoidBField.cpp

References kdfinder::abs(), k, k2, M_PI, and z.

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double Acts::SolenoidBField::B_z	(	const Vector2D &	pos,
		double	scale
	)		const

private

Definition at line 115 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 115 of file SolenoidBField.cpp

References kdfinder::abs(), k, k2, M_PI, and z.

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Acts::Vector3D Acts::SolenoidBField::getField ( const Vector3D & position ) const

retrieve magnetic field value

Parameters

[in] position global 3D position

Returns: magnetic field vector at given position

Definition at line 25 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 25 of file SolenoidBField.cpp

References Acts::VectorHelpers::perp().

Referenced by Acts::Test::BOOST_AUTO_TEST_CASE(), Acts::IntegrationTest::BOOST_DATA_TEST_CASE(), main(), and Acts::solenoidFieldMapper().

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Acts::Vector3D Acts::SolenoidBField::getField	(	const Vector3D &	position,
		Cache &
	)		const

Retrieve magnetic field value.

Parameters

[in]	position	global 3D position
[in]	cache	Cache object, passed through to wrapped BField

Definition at line 40 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 40 of file SolenoidBField.cpp

Acts::Vector2D Acts::SolenoidBField::getField ( const Vector2D & position ) const

Retrieve magnetic field value in local (r,z) coordinates.

Parameters

[in] position local 2D position

Definition at line 45 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 45 of file SolenoidBField.cpp

Acts::Vector3D Acts::SolenoidBField::getFieldGradient	(	const Vector3D &	position,
		ActsMatrixD< 3, 3 > &
	)		const

retrieve magnetic field value & its gradient

Parameters

[in]	position	global 3D position
[out]	derivative	gradient of magnetic field vector as (3x3) matrix

Returns: magnetic field vector

Note: currently the derivative is not calculated

Definition at line 49 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 49 of file SolenoidBField.cpp

Acts::Vector3D Acts::SolenoidBField::getFieldGradient	(	const Vector3D &	position,
		ActsMatrixD< 3, 3 > &	,
		Cache &
	)		const

retrieve magnetic field value & its gradient

Parameters

[in]	position	global 3D position
[out]	derivative	gradient of magnetic field vector as (3x3) matrix
[in]	cache	Cache object, passed through to wrapped BField

Returns: magnetic field vector

Note: currently the derivative is not calculated

Definition at line 54 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 54 of file SolenoidBField.cpp

double Acts::SolenoidBField::k2	(	double	r,
		double	z
	)		const

private

Definition at line 152 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 152 of file SolenoidBField.cpp

References z.

Acts::Vector2D Acts::SolenoidBField::multiCoilField	(	const Vector2D &	pos,
		double	scale
	)		const

private

Definition at line 60 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 60 of file SolenoidBField.cpp

Referenced by SolenoidBField().

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Acts::Vector2D Acts::SolenoidBField::singleCoilField	(	const Vector2D &	pos,
		double	scale
	)		const

private

Definition at line 73 of file SolenoidBField.cpp.

View newest version in sPHENIX GitHub at line 73 of file SolenoidBField.cpp

Member Data Documentation

Config Acts::SolenoidBField::m_cfg

private

Definition at line 136 of file SolenoidBField.hpp.

View newest version in sPHENIX GitHub at line 136 of file SolenoidBField.hpp

Referenced by SolenoidBField().

double Acts::SolenoidBField::m_dz

private

Definition at line 138 of file SolenoidBField.hpp.

View newest version in sPHENIX GitHub at line 138 of file SolenoidBField.hpp

Referenced by SolenoidBField().

double Acts::SolenoidBField::m_R2

private

Definition at line 139 of file SolenoidBField.hpp.

View newest version in sPHENIX GitHub at line 139 of file SolenoidBField.hpp

Referenced by SolenoidBField().

double Acts::SolenoidBField::m_scale

private

Definition at line 137 of file SolenoidBField.hpp.

View newest version in sPHENIX GitHub at line 137 of file SolenoidBField.hpp

Referenced by SolenoidBField().

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

acts/blob/sPHENIX/Core/include/Acts/MagneticField/SolenoidBField.hpp
acts/blob/sPHENIX/Core/src/MagneticField/SolenoidBField.cpp

Classes

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation