|RS||double||0.0||shunt impedance (Ra=2*Rs)|
|CHARGE||double||0.0||beam charge (or use CHARGE element)|
|INITIAL_T||double||0.0||time at which INITIAL_V and INITIAL_PHASE held|
|BETA||double||0.0||normalized load impedance|
|BIN_SIZE||double||0.0||bin size for current histogram (use 0 for autosize)|
|N_BINS||long||20||number of bins for current histogram|
||preload cavity with steady-state field|
|PRELOAD_FACTOR||double||1||multiply preloaded field by this value|
||don't affect the beam until this pass|
||cavity is completely detuned until this pass|
|SAMPLE_INTERVAL||long||1||passes between output to RECORD file|
|RECORD||STRING||NULL||output file for cavity fields|
||if nonzero, don't accumulate field from pass to pass|
|PASS_INTERVAL||long||1||interval in passes at which to apply PASS_INTERVAL times the field (may increase speed)|
|FREQ_WAVEFORM||STRING||NULL||filename=x+y form specification of input file giving frequency/f0 vs time, where f0 is the frequency given with the FREQ parameter|
A simulation of a beam-driven TM monopole mode of an RF cavity.
|Q_WAVEFORM||STRING||NULL||filename=x+y form specification of input file giving qualityFactor/Q0 vs time, where Q0 is the quality factor given the the Q parameter.|
||Number of passes over which to linearly ramp up the impedance to full strength.|
||If nonzero, use algorithm that doesn't requiring binning. Best for few particles, widely spaced.|
|RESET_FOR_EACH_STEP||long||1||If nonzero, voltage and phase are reset for each simulation step.|
||If nonzero, induced voltage from present turn does not affect bunch. Short range wake should be included via WAKE or ZLONGIT element.|
|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 a beam-driven monopole mode cavity using the fundamental theorem of beam loading and phasor rotation.
Normally, the field dumped in the cavity by one particle affects trailing particles in the same turn.
However, if one is also using a
ZLONGIT element to simulate the short-range wake of the cavity, this would be double-counting.
In that case, one can use
LONG_RANGE_ONLY=1 to suppress the same-turn effects of the
Explanation of filename=x+y format: Several elements in elegant make use of data from external files to provide input waveforms.
The external files are SDDS files, which may have many columns. In order to provide a convenient
way to specify both the filename and the columns to use, we frequently employ filename=x+y format
for the parameter value. For example, if the parameter value is
waveform.sdds=t+A, then it
means that columns
A will be taken from file
waveform.sdds. The first
column is always the independent variable (e.g., time, position, or frequency), while the second
column is the dependent quantity.