3.2 monopoleHOMs

• type: Setup command. Required if the next action command is doLongitudinalMotion.
• function: Read in a SDDS format file of HOM definitions to form or add to an internal monopole HOM data structure array. Some of the namelist variables can be used to modify the HOM properties once the growth rate calculation starts.

• filename — SDDS format file of HOM definitions to be interpreted as monopole HOMs. This is the only required variable of the namelist command. The contents of the file is explained in section 4.
• clearPreviousMonopoleHOMs — If this logical flag is set to 1, then the current array of monopole 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 monopole 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 HOM list for the mode that most closely matches the fundamental rf frequency (computed from the circumference and the harmonic number). The program sets that HOM frequency to the fundamental rf frequency, then detunes it to compensate beam loading.
• keepFundamentalFixed — If nonzero, then the fundamental frequency will not be randomized along with other HOMs. This is to simulate what is done in practise, that the fundamental mode tuning is kept fixed by feedback loops. This fixing of fundamental mode can be done through the data column “Fixed” in the HOM file as well.