3.3 dipoleHOMs
- type: Setup command. Required if the next action command is doTransverseMotion.
- function: Read in a SDDS format file of HOM definitions to form or add to an internal dipole
HOM data structure array. Some of the namelist variables can be used to modify the HOM
properties once the growth rate calculation starts.
&dipoleHOMs
STRING filename = NULL
long clearPreviousDipoleHOMs = 0
double deQFactorMultiplier = 1;
double Q = 0;
double staggeringStepMultiplier = 1;
long detuneFundamental = 0;
&end.
- filename — SDDS format file of HOM definitions to be interpreted as dipole HOMs. This is
the only required variable of the namelist command. The contents of the file is explained in
section 4.
- clearPreviousDipoleHOMs — If this logical flag is set to 1, then the current array of dipole
HOMs data structure is cleared before the file filename is read. If the flag is 0, then the
HOM information in the file filename is added to the current array of dipole HOMs data
structure. Thus there can be more than one &monopoleHOMs with different data files.
- deQFactorMultiplier — Factor by which all Q’s in the file will be divided before running
a calculation.
- Q — All HOMs of this file will be assigned the value of Q specified here.
- staggeringStepMultiplier — If there is a frequency staggering step quantity in the HOM
file, then this factor is used to increase the staggering step before a calculation is done.
- detuneFundamental — If nonzero, then clinchor looks in the dipole HOM list for the mode
with the lowest frequency. The program sets that HOM frequency to the closest harmonic
of the fundamental rf frequency, then detunes it to compensate beam loading. This has
applications only for a deflection-mode cavity running at the harmonic of the rf frequency.