impactx::elements::PRot Struct Reference

#include <PRot.H>

Inheritance diagram for impactx::elements::PRot:

Public Types
using	PType = ImpactXParticleContainer::ParticleType

Public Member Functions
	PRot (amrex::ParticleReal phi_in, amrex::ParticleReal phi_out, std::optional< std::string > name=std::nullopt)
void	reverse ()
void	compute_constants (RefPart const &refpart)
template<typename T_Real = amrex::ParticleReal, typename T_IdCpu = uint64_t>
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE void	operator() (T_Real &AMREX_RESTRICT x, T_Real &AMREX_RESTRICT y, T_Real &AMREX_RESTRICT t, T_Real &AMREX_RESTRICT px, T_Real &AMREX_RESTRICT py, T_Real &AMREX_RESTRICT pt, T_IdCpu &AMREX_RESTRICT idcpu, RefPart const &AMREX_RESTRICT refpart) const
AMREX_GPU_HOST AMREX_FORCE_INLINE Map6x6	transport_map (RefPart const &AMREX_RESTRICT refpart) const
Public Member Functions inherited from impactx::elements::mixin::Named
AMREX_GPU_HOST void	set_name (std::string const &new_name)
AMREX_GPU_HOST	Named (std::optional< std::string > name)
AMREX_GPU_HOST_DEVICE	~Named ()
AMREX_GPU_HOST	Named (Named const &other)
AMREX_GPU_HOST Named &	operator= (Named const &other)
AMREX_GPU_HOST_DEVICE	Named (Named &&other) noexcept
AMREX_GPU_HOST_DEVICE Named &	operator= (Named &&other) noexcept
AMREX_FORCE_INLINE std::string	name () const
AMREX_FORCE_INLINE bool	has_name () const
Public Member Functions inherited from impactx::elements::mixin::BeamOptic< PRot >
void	operator() (ImpactXParticleContainer &pc, int step, int period)
void	operator() (ImpactXParticleContainer::iterator &pti, RefPart &AMREX_RESTRICT ref_part, bool spin)
Public Member Functions inherited from impactx::elements::mixin::LinearTransport< PRot >
AMREX_GPU_HOST AMREX_FORCE_INLINE void	operator() (Map6x6 &AMREX_RESTRICT cm, RefPart const &AMREX_RESTRICT ref) const
Public Member Functions inherited from impactx::elements::mixin::Thin
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE void	operator() (RefPart &AMREX_RESTRICT refpart) const
void	reverse ()
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE int	nslice () const
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE amrex::ParticleReal	ds () const
Public Member Functions inherited from impactx::elements::mixin::NoFinalize
void	finalize ()

Public Attributes
amrex::ParticleReal	m_phi_in
amrex::ParticleReal	m_phi_out
	normalized (max) RF voltage drop.

Static Public Attributes
static constexpr auto	type = "PRot"
static constexpr amrex::ParticleReal	degree2rad = ablastr::constant::math::pi / 180.0
Static Public Attributes inherited from impactx::elements::mixin::LinearTransport< PRot >
static constexpr bool	has_linear_transport
Static Public Attributes inherited from amrex::simd::Vectorized< amrex::simd::native_simd_size_particlereal >
static constexpr int	simd_width

Private Attributes
amrex::ParticleReal	m_inv_beta
	RF wavenumber in 1/m.
amrex::ParticleReal	m_sin_theta
amrex::ParticleReal	m_cos_theta
amrex::ParticleReal	m_sin_phi_in
amrex::ParticleReal	m_cos_phi_in

Member Typedef Documentation

PType

using impactx::elements::PRot::PType = ImpactXParticleContainer::ParticleType

Constructor & Destructor Documentation

PRot()

impactx::elements::PRot::PRot ( amrex::ParticleReal phi_in, amrex::ParticleReal phi_out, std::optional< std::string > name = std::nullopt )

inline

An exact pole face rotation in the x-z plane, from a frame in which the reference orbit has angle phi_in with the z-axis, to a frame in which the reference orbit has angle phi_out with the z-axis. The net rotation angle is phi_out - phi_in.

Parameters

phi_in	Initial angle of reference trajectory w/r/t z (degrees)
phi_out	Final angle of reference trajectory w/r/t/ z (degrees)
name	a user defined and not necessarily unique name of the element

Member Function Documentation

compute_constants()

void impactx::elements::PRot::compute_constants ( RefPart const & refpart )

inline

Compute and cache the constants for the push.

In particular, used to pre-compute and cache variables that are independent of the individually tracked particle.

Parameters

refpart

reference particle

operator()()

template<typename T_Real = amrex::ParticleReal, typename T_IdCpu = uint64_t>

AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE void impactx::elements::PRot::operator() ( T_Real &AMREX_RESTRICT x, T_Real &AMREX_RESTRICT y, T_Real &AMREX_RESTRICT t, T_Real &AMREX_RESTRICT px, T_Real &AMREX_RESTRICT py, T_Real &AMREX_RESTRICT pt, T_IdCpu &AMREX_RESTRICT idcpu, RefPart const &AMREX_RESTRICT refpart ) const

inline

This is a prot functor, so that a variable of this type can be used like a prot function.

The

See also

compute_constants method must be called before pushing particles through this operator.

Parameters

x	particle position in x
y	particle position in y
t	particle position in t
px	particle momentum in x
py	particle momentum in y
pt	particle momentum in t
idcpu	particle global index (unused)
refpart	reference particle (unused)

reverse()

void impactx::elements::PRot::reverse ( )

inline

Reverse the element (swap phi_in and phi_out)

transport_map()

AMREX_GPU_HOST AMREX_FORCE_INLINE Map6x6 impactx::elements::PRot::transport_map ( RefPart const &AMREX_RESTRICT refpart ) const

inline

This function returns the linear transport map.

Jacobian at the reference trajectory of the exact pole-face rotation implemented by

See also

operator(). With net rotation angle theta = phi_out - phi_in, the nonzero entries are R(1,1) = cos(phi_in) / cos(phi_out), R(2,2) = cos(phi_out) / cos(phi_in), R(2,6) = -sin(theta) / (beta * cos(phi_in)), R(5,1) = +sin(theta) / (beta * cos(phi_out)), and all other diagonal entries are 1. The derivation uses the trig identity cos(phi_in) * cos(phi_in - phi_out)

• sin(phi_in) * sin(phi_in - phi_out) = cos(phi_out), which simplifies the x-denominator pz|_0 -> cos(phi_out). Symplecticity of the reduced (x, px, t, pt) block was verified with SymPy (R^T J R = J).

The (y, py) sub-block is the identity: pole-face rotation in the x-z plane does not mix the vertical plane at linear order.

Reference: MaryLie 3.0 Users' Manual, Sect. 6.5 ("Plane Rotation"); A. J. Dragt, Lie Methods for Nonlinear Dynamics with Applications to Accelerator Physics, v. Nov. 2020, Appendix V ("PROT without and in the Presence of a Magnetic Field").

Ideal behavior only: alignment and rotation errors are ignored; the linearization is at (x, y, t) = (0, 0, 0) and (px, py, pt) = (0, 0, 0).

Parameters

[in]

refpart

reference particle (used for beta)

Returns

6x6 transport matrix

Member Data Documentation

degree2rad

amrex::ParticleReal impactx::elements::PRot::degree2rad = ablastr::constant::math::pi / 180.0

staticconstexpr

m_cos_phi_in

amrex::ParticleReal impactx::elements::PRot::m_cos_phi_in

private

m_cos_theta

amrex::ParticleReal impactx::elements::PRot::m_cos_theta

private

m_inv_beta

amrex::ParticleReal impactx::elements::PRot::m_inv_beta

private

RF wavenumber in 1/m.

m_phi_in

amrex::ParticleReal impactx::elements::PRot::m_phi_in

m_phi_out

amrex::ParticleReal impactx::elements::PRot::m_phi_out

normalized (max) RF voltage drop.

m_sin_phi_in

amrex::ParticleReal impactx::elements::PRot::m_sin_phi_in

private

m_sin_theta

amrex::ParticleReal impactx::elements::PRot::m_sin_theta

private

type

auto impactx::elements::PRot::type = "PRot"

staticconstexpr

---

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

• /home/docs/checkouts/readthedocs.org/user_builds/impactx/checkouts/1402/src/elements/PRot.H