A SIMPLE REAL-TIME BEAM TUNING PROGRAM FOR THE KEKB INJECTOR LINAC

A simple real-time beam tuning program has been devel- oped for use at the KEK B-Factory injector linac. The program features the ability to adjust an arbitrary combi- nation of parameters (e.g. magnet currents and RF phases) in order to optimize an arbitrary combination of monitor values (e.g. the ratio of a downstream beam current to gun current). Based on the downhill-simplex method(2)(?), it requires no knowledge of beamline details. An additional "persistence" parameter is used to adjust the treatment of pulse-to-pulse variations of monitor values while mapping the parameter-space terrain, and controls the peak-holding performance in the presence of both statistical fluctuations and long-term drift. Preliminary results from the commis- sioning of the KEKB injector linac and plans for the future are discussed.