LSCDRIFT

Longitudinal space charge impedance
Parallel capable? : yes

Parameter Name	Units	Type	Default	Description
L	$M$	double	0.0	length
LEFFECTIVE	$M$	double	0.0	effective length (used if L=0)
BINS		long	0	number of bins for current histogram
SMOOTHING		long	0	Use Savitzky-Golay filter to smooth current histogram?
SG_HALFWIDTH		long	1	Savitzky-Golay filter half-width for smoothing current histogram
SG_ORDER		long	1	Savitzky-Golay filter order for smoothing current histogram
INTERPOLATE		long	1	Interpolate wake?
LOW_FREQUENCY_CUTOFF0		double	-1	Highest spatial frequency at which low-frequency cutoff filter is zero. If not positive, no low-frequency cutoff filter is applied. Frequency is in units of Nyquist (0.5/binsize).
LOW_FREQUENCY_CUTOFF1		double	-1	Lowest spatial frequency at which low-frequency cutoff filter is 1. If not given, defaults to LOW_FREQUENCY_CUTOFF1.
HIGH_FREQUENCY_CUTOFF0		double	-1	Spatial frequency at which smoothing filter begins. If not positive, no frequency filter smoothing is done. Frequency is in units of Nyquist (0.5/binsize).
HIGH_FREQUENCY_CUTOFF1		double	-1	Spatial frequency at which smoothing filter is 0. If not given, defaults to HIGH_FREQUENCY_CUTOFF0.

Longitudinal space charge impedance

Parameter Name	Units	Type	Default	Description
RADIUS_FACTOR		double	1.7	LSC radius is (Sx+Sy)/2*RADIUS_FACTOR
LSC		long	1	Include longitudinal space-charge impedance? If zero, acts like ordinary drift.
GROUP		string	NULL	Optionally used to assign an element to a group, with a user-defined name. Group names will appear in the parameter output file in the column ElementGroup

This element simulates longitudinal space charge in a drift space using the method described in [22]. This is based on the longitudinal space charge impedance per unit length

$$Z_{lsc}(k) = \frac{i Z_0}{\pi k r_b^2} \left[ 1 - \frac{kr_b}{\gamma}K_1 \left(\frac{kr_b}{\gamma}\right)\right]$$ (21)

If L is 0 and LEFFECTIVE is not, then the element provides a LSC kick with impedance given by $Z_{lsc} L_{effective}$. This can be used to insert an LSC kick that integrates the longitudinal space charge effect of a section of a lattice. This should be used only for cases where there is very little relative longitudinal motion of particles.