Digital Control of Bevatron Acceleration Cycle

Control of the Bevatron acceleration system had been entirely analogue until developments in proton extraction techniques required substantial reduction of hum and noise during the acceleration cycle. The decision was made to employ a digital processor to control the acceleration cycle. An algorithm is developed which allows introduction of radial-feedback data into the digital processor and the real-time error signal is combined with arbitrary field dependent functions for transmission to the existing master. oscillator. A high common-mode rejection digital system is utilized to enter the resultant control data directly into the master-oscillator environment before conversion into the required analog reference for frequency modulation. A comprehensive hardware "calculator" provides a continuous curve of digital representations to be sent along to the oscillator. The paper describes implementation of these facilities and the development of operator-oriented interface to capitalize upon the flexibilities inherent within a digitally oriented system.