Particles¶

class particles.Beam(*args, **kwargs)¶

property alpha_x: Tensor¶: Alpha function in x direction in rad.

property alpha_y: Tensor¶: Alpha function in y direction in rad.

property beta_x: Tensor¶: Beta function in x direction in meters.

property beta_y: Tensor¶: Beta function in y direction in meters.

broadcast(shape: Size) → Beam¶: Broadcast beam to new shape.

property emittance_x: Tensor¶: Emittance of the beam in x direction in m*rad.

property emittance_y: Tensor¶: Emittance of the beam in y direction in m*rad.

empty = "I'm an empty beam!"¶

classmethod from_astra(path: str, **kwargs) → Beam¶: Load an Astra particle distribution as a Cheetah Beam.

classmethod from_ocelot(parray) → Beam¶: Convert an Ocelot ParticleArray parray to a Cheetah Beam.

Create beam that with given beam parameters.

Parameters:

n – Number of particles to generate.
mu_x – Center of the particle distribution on x in meters.
mu_xp – Center of the particle distribution on x’=px/px’ (trace space) in rad.
mu_y – Center of the particle distribution on y in meters.
mu_yp – Center of the particle distribution on y’ in rad.
sigma_x – Sigma of the particle distribution in x direction in meters.
sigma_xp – Sigma of the particle distribution in x’ direction in rad.
sigma_y – Sigma of the particle distribution in y direction in meters.
sigma_yp – Sigma of the particle distribution in y’ direction in rad.
sigma_s – Sigma of the particle distribution in s direction in meters.
sigma_p – Sigma of the particle distribution in p direction in meters.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.

Create a beam from twiss parameters.

Parameters:

beta_x – Beta function in x direction in meters.
alpha_x – Alpha function in x direction in rad.
emittance_x – Emittance in x direction in m*rad.
beta_y – Beta function in y direction in meters.
alpha_y – Alpha function in y direction in rad.
emittance_y – Emittance in y direction in m*rad.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.

property mu_p: Tensor¶

property mu_s: Tensor¶

property mu_x: Tensor¶

property mu_xp: Tensor¶

property mu_y: Tensor¶

property mu_yp: Tensor¶

property normalized_emittance_x: Tensor¶: Normalized emittance of the beam in x direction in m*rad.

property normalized_emittance_y: Tensor¶: Normalized emittance of the beam in y direction in m*rad.

property parameters: dict¶

Return an iterator over module parameters.

This is typically passed to an optimizer.

Args:

recurse (bool): if True, then yields parameters of this module: and all submodules. Otherwise, yields only parameters that are direct members of this module.

Yields:

Parameter: module parameter

Example:

>>> # xdoctest: +SKIP("undefined vars")
>>> for param in model.parameters():
>>>     print(type(param), param.size())
<class 'torch.Tensor'> (20L,)
<class 'torch.Tensor'> (20L, 1L, 5L, 5L)

property relativistic_beta: Tensor¶

property relativistic_gamma: Tensor¶

property sigma_p: Tensor¶

property sigma_s: Tensor¶

property sigma_x: Tensor¶

property sigma_xp: Tensor¶

property sigma_xxp: Tensor¶

property sigma_y: Tensor¶

property sigma_yp: Tensor¶

property sigma_yyp: Tensor¶

Create version of this beam that is transformed to new beam parameters.

Parameters:

mu_x – Center of the particle distribution on x in meters.
mu_xp – Center of the particle distribution on x’ in rad.
mu_y – Center of the particle distribution on y in meters.
mu_yp – Center of the particle distribution on y’ in rad.
sigma_x – Sigma of the particle distribution in x direction in meters.
sigma_xp – Sigma of the particle distribution in x’ direction in rad.
sigma_y – Sigma of the particle distribution in y direction in meters.
sigma_yp – Sigma of the particle distribution in y’ direction in rad.
sigma_s – Sigma of the particle distribution in s direction in meters.
sigma_p – Sigma of the particle distribution in p direction,

dimensionless. :param energy: Energy of the beam in eV. :param total_charge: Total charge of the beam in C.

class particles.ParameterBeam(mu: Tensor, cov: Tensor, energy: Tensor, total_charge: Tensor | None = None, device=None, dtype=torch.float32)¶

Beam of charged particles, where each particle is simulated.

Parameters:

mu – Mu vector of the beam.
cov – Covariance matrix of the beam.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.
device – Device to use for the beam. If “auto”, use CUDA if available. Note: Compuationally it would be faster to use CPU for ParameterBeam.

broadcast(shape: Size) → ParameterBeam¶: Broadcast beam to new shape.

classmethod from_astra(path: str, device=None, dtype=torch.float32) → ParameterBeam¶: Load an Astra particle distribution as a Cheetah Beam.

classmethod from_ocelot(parray, device=None, dtype=torch.float32) → ParameterBeam¶: Load an Ocelot ParticleArray parray as a Cheetah Beam.

Create beam that with given beam parameters.

Parameters:

n – Number of particles to generate.
mu_x – Center of the particle distribution on x in meters.
mu_xp – Center of the particle distribution on x’=px/px’ (trace space) in rad.
mu_y – Center of the particle distribution on y in meters.
mu_yp – Center of the particle distribution on y’ in rad.
sigma_x – Sigma of the particle distribution in x direction in meters.
sigma_xp – Sigma of the particle distribution in x’ direction in rad.
sigma_y – Sigma of the particle distribution in y direction in meters.
sigma_yp – Sigma of the particle distribution in y’ direction in rad.
sigma_s – Sigma of the particle distribution in s direction in meters.
sigma_p – Sigma of the particle distribution in p direction in meters.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.

Create a beam from twiss parameters.

Parameters:

beta_x – Beta function in x direction in meters.
alpha_x – Alpha function in x direction in rad.
emittance_x – Emittance in x direction in m*rad.
beta_y – Beta function in y direction in meters.
alpha_y – Alpha function in y direction in rad.
emittance_y – Emittance in y direction in m*rad.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.

property mu_p: Tensor¶

property mu_s: Tensor¶

property mu_x: Tensor¶

property mu_xp: Tensor¶

property mu_y: Tensor¶

property mu_yp: Tensor¶

property sigma_p: Tensor¶

property sigma_s: Tensor¶

property sigma_x: Tensor¶

property sigma_xp: Tensor¶

property sigma_xxp: Tensor¶

property sigma_y: Tensor¶

property sigma_yp: Tensor¶

property sigma_yyp: Tensor¶

Create version of this beam that is transformed to new beam parameters.

Parameters:

n – Number of particles to generate.
mu_x – Center of the particle distribution on x in meters.
mu_xp – Center of the particle distribution on x’ in rad.
mu_y – Center of the particle distribution on y in meters.
mu_yp – Center of the particle distribution on y’ in rad.
sigma_x – Sigma of the particle distribution in x direction in meters.
sigma_xp – Sigma of the particle distribution in x’ direction in rad.
sigma_y – Sigma of the particle distribution in y direction in meters.
sigma_yp – Sigma of the particle distribution in y’ direction in rad.
sigma_s – Sigma of the particle distribution in s direction in meters.
sigma_p – Sigma of the particle distribution in p, dimensionless.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.

class particles.ParticleBeam(particles: Tensor, energy: Tensor, particle_charges: Tensor | None = None, device=None, dtype=torch.float32)¶

Beam of charged particles, where each particle is simulated.

Parameters:

particles – List of 7-dimensional particle vectors.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.
device – Device to move the beam’s particle array to. If set to “auto” a CUDA GPU is selected if available. The CPU is used otherwise.

broadcast(shape: Size) → ParticleBeam¶: Broadcast beam to new shape.

classmethod from_astra(path: str, device=None, dtype=torch.float32) → ParticleBeam¶: Load an Astra particle distribution as a Cheetah Beam.

classmethod from_ocelot(parray, device=None, dtype=torch.float32) → ParticleBeam¶: Convert an Ocelot ParticleArray parray to a Cheetah Beam.

Generate Cheetah Beam of random particles.

Parameters:

num_particles – Number of particles to generate.
mu_x – Center of the particle distribution on x in meters.
mu_y – Center of the particle distribution on y in meters.
mu_xp – Center of the particle distribution on x’ in rad.
mu_yp – Center of the particle distribution on y’ in metraders.
sigma_x – Sigma of the particle distribution in x direction in meters.
sigma_y – Sigma of the particle distribution in y direction in meters.
sigma_xp – Sigma of the particle distribution in x’ direction in rad.
sigma_yp – Sigma of the particle distribution in y’ direction in rad.
sigma_s – Sigma of the particle distribution in s direction in meters.
sigma_p – Sigma of the particle distribution in p, dimensionless.
cor_x – Correlation between x and x’.
cor_y – Correlation between y and y’.
cor_s – Correlation between s and p.
energy – Energy of the beam in eV.
device – Device to move the beam’s particle array to. If set to “auto” a CUDA GPU is selected if available. The CPU is used otherwise.

Total_charge:

Total charge of the beam in C.

Create a beam from twiss parameters.

Parameters:

beta_x – Beta function in x direction in meters.
alpha_x – Alpha function in x direction in rad.
emittance_x – Emittance in x direction in m*rad.
beta_y – Beta function in y direction in meters.
alpha_y – Alpha function in y direction in rad.
emittance_y – Emittance in y direction in m*rad.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.

Generate Cheetah Beam of n linspaced particles.

Parameters:

n – Number of particles to generate.
mu_x – Center of the particle distribution on x in meters.
mu_y – Center of the particle distribution on y in meters.
mu_xp – Center of the particle distribution on x’ in rad.
mu_yp – Center of the particle distribution on y’ in rad.
sigma_x – Sigma of the particle distribution in x direction in meters.
sigma_y – Sigma of the particle distribution in y direction in meters.
sigma_xp – Sigma of the particle distribution in x’ direction in rad.
sigma_yp – Sigma of the particle distribution in y’ direction in rad.
sigma_s – Sigma of the particle distribution in s direction in meters.
sigma_p – Sigma of the particle distribution in p, dimensionless.
energy – Energy of the beam in eV.
device – Device to move the beam’s particle array to. If set to “auto” a CUDA GPU is selected if available. The CPU is used otherwise.

property mu_p: Tensor | None¶

property mu_s: Tensor | None¶

property mu_x: Tensor | None¶

property mu_xp: Tensor | None¶

property mu_y: float | None¶

property mu_yp: Tensor | None¶

property num_particles: int¶

property ps: Tensor | None¶

property sigma_p: Tensor | None¶

property sigma_s: Tensor | None¶

property sigma_x: Tensor | None¶

property sigma_xp: Tensor | None¶

property sigma_xxp: Tensor¶

property sigma_y: Tensor | None¶

property sigma_yp: Tensor | None¶

property sigma_yyp: Tensor¶

property ss: Tensor | None¶

property total_charge: Tensor¶

Create version of this beam that is transformed to new beam parameters.

Parameters:

n – Number of particles to generate.
mu_x – Center of the particle distribution on x in meters.
mu_y – Center of the particle distribution on y in meters.
mu_xp – Center of the particle distribution on x’ in rad.
mu_yp – Center of the particle distribution on y’ in rad.
sigma_x – Sigma of the particle distribution in x direction in meters.
sigma_y – Sigma of the particle distribution in y direction in meters.
sigma_xp – Sigma of the particle distribution in x’ direction in rad.
sigma_yp – Sigma of the particle distribution in y’ direction in rad.
sigma_s – Sigma of the particle distribution in s direction in meters.
sigma_p – Sigma of the particle distribution in p, dimensionless.
energy – Energy of the beam in eV.
total_charge – Total charge of the beam in C.
device – Device to move the beam’s particle array to. If set to “auto” a CUDA GPU is selected if available. The CPU is used otherwise.

Generate a particle beam with spatially uniformly distributed particles inside an ellipsoid, i.e. a waterbag distribution.

Note that:

The generated particles do not have correlation in the momentum directions, and by default a cold beam with no divergence is generated.
For batched generation, parameters that are not None must have the same shape.

Parameters:

num_particles – Number of particles to generate.
radius_x – Radius of the ellipsoid in x direction in meters.
radius_y – Radius of the ellipsoid in y direction in meters.
radius_s – Radius of the ellipsoid in s (longitudinal) direction

in meters. :param sigma_xp: Sigma of the particle distribution in x’ direction in rad, default is 0. :param sigma_yp: Sigma of the particle distribution in y’ direction in rad, default is 0. :param sigma_p: Sigma of the particle distribution in p, dimensionless. :param energy: Energy of the beam in eV. :param total_charge: Total charge of the beam in C. :param device: Device to move the beam’s particle array to. :param dtype: Data type of the generated particles.

Returns:: ParticleBeam with uniformly distributed particles inside an ellipsoid.

property xps: Tensor | None¶

property xs: Tensor | None¶

property yps: Tensor | None¶

property ys: Tensor | None¶