| Parameter Name | Units | Type | Default | Description |
| RA | double | 0.0 | shunt impedance | |
| RS | double | 0.0 | shunt impedance (Ra=2*Rs) | |
| Q | double | 0.0 | cavity Q | |
| FREQ | double | 0.0 | frequency | |
| CHARGE | double | 0.0 | beam charge (or use CHARGE element) | |
| 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 | |
| PLANE | STRING | both | x, y, or both | |
| SAMPLE_INTERVAL | long | 1 | passes between output to RECORD file | |
| PER_PARTICLE_OUTPUT | long | 0 |
If non-zero, then in BINLESS mode, provides per-particle output of RECORD data. | |
| RECORD | STRING | NULL | output file for cavity data | |
| SINGLE_PASS | long | 0 |
if nonzero, don't accumulate field from pass to pass | |
| RIGID_UNTIL_PASS | long | 0 |
don't affect the beam until this pass | |
| DX | double | 0.0 | misalignment | |
| DY | double | 0.0 | misalignment | |
| XFACTOR | double | 1 | factor by which to multiply shunt impedances | |
| YFACTOR | double | 1 | factor by which to multiply shunt impedances | |
| RAMP_PASSES | long | 0 |
Number of passes over which to linearly ramp up the impedance to full strength. | |
| BINLESS | long | 0 |
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. |
A simulation of a beam-driven TM dipole mode of an RF cavity.
| Parameter Name | Units | Type | Default | Description |
| LONG_RANGE_ONLY | long | 0 |
If nonzero, induced voltage from present turn does not affect bunch. Short range wake should be included via TRWAKE or ZTRANSVERSE 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 dipole 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 TRWAKE or ZTRANSVSE 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 RFMODE element.