![iZ [ kr ( kr ) ]
Zlsc(k ) =---02 1 - --bK1 --b
πkr b γ γ](elegant119x.png)
Longitudinal space charge impedance
Parallel capable? : yes
GPU capable? : yes
Back-tracking 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 | short | 0 | Use Savitzky-Golay filter to smooth current histogram? |
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| SG_HALFWIDTH | short | 1 | Savitzky-Golay filter half-width for smoothing current histogram |
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| SG_ORDER | short | 1 | Savitzky-Golay filter order for smoothing current histogram |
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| INTERPOLATE | short | 1 | Interpolate wake? |
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| LSC | short | 1 | Include longitudinal space-charge impedance? If zero, acts like ordinary drift. |
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| AUTO_LEFFECTIVE | short | 0 | In nonzero and if L=0, the LEFFECTIVE parameter is set to the length of the previous element. |
|
| 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). |
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| 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). |
|
LSCDRIFT continued
Longitudinal space charge impedance
| Parameter Name | Units | Type | Default | Description |
| HIGH_FREQUENCY_CUTOFF1 | double | -1 | Spatial frequency at which smoothing filter is 0. If not given, defaults to HIGH_FREQUENCY_CUTOFF0. |
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| RADIUS_FACTOR | double | 1.7 | LSC radius is (Sx+Sy)/2*RADIUS_FACTOR |
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| 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 |
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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
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| (70) |
If L is 0 and LEFFECTIVE is not, then the element provides a LSC kick with impedance given by ZlscLeffective. 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.
Two simple filters are provided.
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LSRMDLTR