Parameter Name | Units | Type | Default | Description |
INPUTFILE | STRING | NULL | name of file giving Green functions | |
TCOLUMN | STRING | NULL | column in INPUTFILE containing time data | |
WXCOLUMN | STRING | NULL | column in INPUTFILE containing x Green function | |
WYCOLUMN | STRING | NULL | column in INPUTFILE containing y Green function | |
CHARGE | ![]() |
double | 0.0 | beam charge (or use CHARGE element) |
FACTOR | ![]() |
double | 1 | factor to multiply wake by |
N_BINS | long | 128 | number of bins for current histogram | |
INTERPOLATE | long | 0 |
interpolate wake? | |
SMOOTHING | long | 0 |
smooth current histogram? | |
SG_HALFWIDTH | long | 4 | Savitzky-Golay filter half-width for smoothing | |
SG_ORDER | long | 1 | Savitzky-Golay filter order for smoothing | |
DX | ![]() |
double | 0.0 | misalignment |
DY | ![]() |
double | 0.0 | misalignmnet |
The input file for this element gives the transverse-wake Green
functions, and
, versus time behind the particle. The
units of the wakes are V/C/m, so this element simulates the integrated
wake of some structure (e.g., a cell or series of cells). If you
have, for example, the wake for a cell and you need the wake for N
cells, then you may use the FACTOR parameter to make the
appropriate multiplication. The values of the time coordinate should
begin at 0 and be equi-spaced. A positive value of time represents
the distance behind the exciting particle.
Use of the CHARGE parameter on the TRWAKE element is disparaged. It is preferred to use the CHARGE element as part of your beamline to define the charge.
Setting the N_BINS paramater to 0 is recommended. This results in auto-scaling of the number of bins to accomodate the beam. The bin size is fixed by the spacing of the time points in the wake.
The default degree of smoothing (SG_HALFWIDTH=4) may be excessive. It is suggested that users vary this parameter to verify that results are reliable if smoothing is employed (SMOOTHING=1).