General description.

The Phase Feed Back program was design to compensate for the phase drifts in the Gun RF system. It measures the signal from Phase / Amplitude Detector (PAD) unit that is proportional to the phase difference between master oscillator and high power RF output of the klystron. The program measures the PAD signal using an oscilloscope located near the low level RF electronics in the south part of the mezzanine. The connection to the oscilloscope is through an Internet GPIB line. The program applies calculated corrections to the gun electronic phase shifter to maintain the klystron output at a constant value. This does not correct shot to shot jitter, only long term drifts. The connection to the gun phase shifter is done using an Internet connection to the ATF database.

Phase correction history for the last HGHG running day.