Application of Crossbar Relays to the Control of a Buncher Ring

The high-current beam research at Livermore requires the capability of bunching the 700-A, 6-MeV electron beam of the Astron electron accelerator. The mass of the particles in the beam are modulated by an RF cavity and then transported around a 30-ft-diam.ring to produce bunching. The ring uses a set of eight bending magnets, a set of eight focusing magnets, and eight defocusing magnets. Each set of magnets is series connected and excited from a single power supply. To provide the necessary field trimming, a three-decade set of digitally actuated resistors is connected across each magnet.