Computerized Measurement of Injection Tunes at the Zero Gradient Synchrotron

Half of the Zero Gradient Synchrotron (ZGS) ring is filled with a 1.0 microsecond, debunched beampulse from the linac. As the main magnetic field rises, particle orbits spiral inward. The difference signal from a pi induction electrode is used to obtain radial position data of the coasting beam as a function of time. A sharp cutoff bandpass filter passes betatron tune frequency components to a computing counter. The computing counter uses a resident software program to calculate tune values in real time. Data is available immediately which allows corrections to be made on line.