at.physics.revolution#

Revolution frequency, momentum compaction factor, slip factor

Functions

get_mcf(ring[, dp, keep_lattice, fit_order, ...])

Compute the momentum compaction factor \(\alpha\)

get_slip_factor(ring, **kwargs)

Compute the slip factor \(\eta=1/\gamma^2-\alpha\)

get_revolution_frequency(ring[, dp, dct, df])

Compute the revolution frequency of the full ring [Hz]
get_mcf(ring, dp=0.0, keep_lattice=False, fit_order=1, n_step=2, **kwargs)[source]#

Compute the momentum compaction factor \(\alpha\)

Parameters:

  • ring (Lattice) – Lattice description (ring.is_6d must be False)

  • dp (float) – Momentum deviation

  • keep_lattice (bool) – Assume no lattice change since the previous tracking.

  • fit_order (int) – Maximum momentum compaction factor order to be fitted. Default to 1, corresponding to the first-order momentum compaction factor.

  • n_step (int) – Number of different calculated momentum deviations to be fitted with a polynomial. Default to 2.

Keyword Arguments:

DPStep (float) – Momentum step size. Default: DConstant.DPStep

Returns:

mcf (float/array) – Momentum compaction factor \(\alpha\) up to the order fit_order. Returns a float if fit_order==1 otherwise returns an array.

get_revolution_frequency(ring, dp=None, dct=None, df=None)[source]#

Compute the revolution frequency of the full ring [Hz]

Parameters:

  • ring (Lattice) – Lattice description

  • dp (float) – Momentum deviation. Defaults to None

  • dct (float) – Path lengthening. Defaults to None

  • df (float) – Deviation of RF frequency. Defaults to None

Returns:

frev – Revolution frequency [Hz]

get_slip_factor(ring, **kwargs)[source]#

Compute the slip factor \(\eta=1/\gamma^2-\alpha\)

Parameters:

ring (Lattice) – Lattice description (ring.is_6d must be False)

Keyword Arguments:
Returns:

eta (float) – Slip factor \(\eta\)