A single-pass impedance combining longitudinal monopole, transverse dipole, and transverse quadrupole
channels read from one SDDS file. Equivalent to a co-located ZLONGIT and one or more
ZTRANSVERSE elements, but performs particle binning and bunch assignment only once.
Parallel capable? : yes
GPU capable? : no
Back-tracking capable? : no
Spin-tracking capable? : no
| Parameter Name | Units | Type | Default | Description |
| INPUTFILE | STRING | NULL | SDDS file containing frequency and impedance columns |
|
| FREQCOLUMN | STRING | NULL | column in INPUTFILE containing frequency |
|
| ZL_REAL | STRING | NULL | column in INPUTFILE giving real part of longitudinal monopole impedance ZbLn(f) |
|
| ZL_IMAG | STRING | NULL | column in INPUTFILE giving imaginary part of longitudinal monopole impedance ZbLn(f) |
|
| ZXD_REAL | STRING | NULL | column in INPUTFILE giving real part of x dipole impedance ZbxDn(f) |
|
| ZXD_IMAG | STRING | NULL | column in INPUTFILE giving imaginary part of x dipole impedance ZbxDn(f) |
|
| ZYD_REAL | STRING | NULL | column in INPUTFILE giving real part of y dipole impedance ZbyDn(f) |
|
| ZYD_IMAG | STRING | NULL | column in INPUTFILE giving imaginary part of y dipole impedance ZbyDn(f) |
|
| ZXQ_REAL | STRING | NULL | column in INPUTFILE giving real part of x quadrupole impedance ZbxQn(f) |
|
| ZXQ_IMAG | STRING | NULL | column in INPUTFILE giving imaginary part of x quadrupole impedance ZbxQn(f) |
|
| ZYQ_REAL | STRING | NULL | column in INPUTFILE giving real part of y quadrupole impedance ZbyQn(f) |
|
| ZYQ_IMAG | STRING | NULL | column in INPUTFILE giving imaginary part of y quadrupole impedance ZbyQn(f) |
|
| BIN_SIZE | S | double | 0.0 | bin size for current histogram (ignored: determined from impedance file) |
IMPEDANCE continued
A single-pass impedance combining longitudinal monopole, transverse dipole, and transverse quadrupole
channels read from one SDDS file. Equivalent to a co-located ZLONGIT and one or more
ZTRANSVERSE elements, but performs particle binning and bunch assignment only once.
| Parameter Name | Units | Type | Default | Description |
| INTERPOLATE | long | 0 | interpolate wake voltage to particle time? |
|
| N_BINS | long | 128 | number of bins (ignored: determined from impedance file) |
|
| MAX_N_BINS | long | 0 | maximum number of bins (ignored) |
|
| SMOOTHING | long | 0 | Use Savitzky-Golay filter to smooth driver histograms? |
|
| SG_ORDER | long | 1 | Savitzky-Golay filter order for smoothing |
|
| SG_HALFWIDTH | long | 4 | Savitzky-Golay filter halfwidth for smoothing |
|
| DX | M | double | 0.0 | x misalignment (applied to transverse driver coordinates) |
| DY | M | double | 0.0 | y misalignment (applied to transverse driver coordinates) |
| FACTOR | double | 1 | global scale factor applied to every channel |
|
| XFACTOR | double | 1 | factor by which to multiply horizontal dipole impedance |
|
| YFACTOR | double | 1 | factor by which to multiply vertical dipole impedance |
|
| ZFACTOR | double | 1 | factor by which to multiply longitudinal impedance |
|
| QXFACTOR | double | 1 | factor by which to multiply horizontal quadrupole impedance |
|
| QYFACTOR | double | 1 | factor by which to multiply vertical quadrupole impedance |
|
| WAKES | STRING | NULL | filename for output of wake potentials and driver histograms |
|
IMPEDANCE continued
A single-pass impedance combining longitudinal monopole, transverse dipole, and transverse quadrupole
channels read from one SDDS file. Equivalent to a co-located ZLONGIT and one or more
ZTRANSVERSE elements, but performs particle binning and bunch assignment only once.
| Parameter Name | Units | Type | Default | Description |
| WAKE_INTERVAL | long | 1 | interval in passes at which to output wakes |
|
| WAKE_START | long | 0 | pass at which to start to output wakes |
|
| WAKE_END | long | -1 | pass at which to stop to output wakes (-1 to disable) |
|
| START_ON_PASS | long | 0 | the pass on which the impedance effects start |
|
| RAMP_PASSES | long | 0 | number of passes over which to linearly ramp up the impedance to full strength |
|
| HIGH_FREQUENCY_CUTOFF0 | double | -1 | frequency at which smoothing filter begins (units of Nyquist). If not positive, no smoothing filter is applied. |
|
| HIGH_FREQUENCY_CUTOFF1 | double | -1 | frequency at which smoothing filter reaches zero. Defaults to HIGH_FREQUENCY_CUTOFF0. |
|
| BUNCHED_BEAM_MODE | long | 1 | if non-zero, then do calculations bunch-by-bunch |
|
| START_BUNCH | long | -1 | in bunched beam mode, if non-negative, starting bunch index for computation |
|
| END_BUNCH | long | -1 | in bunched beam mode, if non-negative, ending bunch index for computation |
|
| ALLOW_LONG_BEAM | long | 0 | allow beam longer than covered by impedance data? |
|
| AREA_WEIGHT | long | 0 | use area-weighted binning for the longitudinal current histogram? |
|
| REVERSE_TIME_ORDER | long | 0 | reverse time-order of particles for the longitudinal wake (acausal mode) |
|
IMPEDANCE continued
A single-pass impedance combining longitudinal monopole, transverse dipole, and transverse quadrupole
channels read from one SDDS file. Equivalent to a co-located ZLONGIT and one or more
ZTRANSVERSE elements, but performs particle binning and bunch assignment only once.
| Parameter Name | Units | Type | Default | Description |
| 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 |
|
The IMPEDANCE element combines the physics of a co-located ZLONGIT (longitudinal monopole impedance) and one or more ZTRANSVERSE elements (transverse dipole or quadrupole impedances) into a single element. In a case where all these components are modeled, using a single IMPEDANCE element reduces computational effort by about 40% compared to three separate elements (single ZLONGIT plus two ZTRANSVERSE elements for dipole and quadrupole).