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BeamTransform

This section provides documentation for the BeamTransform class, which is used for beam matching using Twiss parameters. The class applies beam matching based on the specified parameters, and removes offsets from the beam if required.

BeamTransform Class​

The BeamTransform class performs beam matching by adjusting the beam's parameters (using the Twiss formalism) to meet the specified conditions. It includes an option to remove offsets from the beam and applies the matching transformation to the beam using the beam_matching method.

Parameters:​

  • tws (Twiss or None): A Twiss object that contains the Twiss parameters for the beam. If None, the Twiss parameters are derived from the x_opt and y_opt attributes.
  • x_opt (list or None): Obsolete list of Twiss parameters for the horizontal plane, [alpha, beta, mu (phase advance)]. If None, it uses tws to get the parameters.
  • y_opt (list or None): Obsolete list of Twiss parameters for the vertical plane, [alpha, beta, mu (phase advance)]. If None, it uses tws to get the parameters.
  • remove_offsets (bool): If True, offsets are removed from the beam before applying the matching. Default is True.
  • bounds (list): Specifies the bounds in terms of sigmas (e.g., [-5, 5]). This defines the region of the beam to be matched. Default is [-5, 5].
  • slice (str or None): Specifies a beam slice to be matched. If None, the entire beam is considered. If set to "Imax" or "Emax", the beam is matched to that slice, and the bounds parameter is ignored.

Methods:​

__init__(self, tws=None, x_opt=None, y_opt=None, **kw)​

Constructor to initialize the BeamTransform class. It sets the Twiss parameters, options for offset removal, bounds for beam matching, and slice type.

twiss(self)​

This property returns the Twiss object used for the beam matching. If the tws parameter is not provided, it constructs a new Twiss object using the x_opt and y_opt values. A warning is logged if x_opt and y_opt are used (since they are obsolete).

apply(self, p_array, dz)​

Applies the beam transformation to the particle array (p_array) using the specified bounds and Twiss parameters. It invokes the beam_matching method to perform the matching transformation.

Summary​

The BeamTransform class is designed for beam matching in particle accelerators using the Twiss formalism. It allows for adjusting the beam's parameters to achieve a desired beam profile, with options to remove offsets and specify the region of the

beam to be matched. This class is particularly useful when optimizing beam parameters in accelerators or light sources. The class provides flexibility in defining beam boundaries and slices for matching, and handles both horizontal and vertical matching based on Twiss parameters.