Spark location in RF cavities

A spark detection system was constructed at the test station for the 400 MeV Linac Upgrade at Fermilab. To locate sparks in RF cavities we placed five ion gauge detectors along an accelerating module. The method used in detecting the spark location is based on the fact that sparks create pressure disturbances which travel throughout the cavity. Pressure signals from all five detectors are amplified using relatively fast amplifiers and then digitally recorded or monitored on the scope. The data recording is triggered by spark generation and data are recorded at a 15 Hz repetition rate. The system was also used to study different schemes for preferential spark generation at times that would be least detrimental to accelerator operations