A brief introduction to the software used to run up SRF cavities
Full source code can be found here. It can be run natively on unix systems using the Local PyDM/Simulacrum Setup instructions
Overview
The need for automation arose from the human error involved in manually implementing a long list of clearly defined steps.
The basic procedure is:
- Run an SSA calibration
- Tune a cavity to resonance (a detune of 0Hz)
- Characterize the cavity and calculate the probe Q
- Ramp the RF to the desired amplitude (ADES)
SSA Calibration
Using a previously saved drive max found during initial cryomodule commissioning as a starting point (or 1 for the harmonic linearizers), it recursively runs an SSA calibration with decreasing drive max until either the calibration succeeds or the max forward power reads as too low (currently defined as less than 3kW).