Controls and interlocks for a prototype 1 MHz beam chopper

A prototype 1-MHz beam chopper for the proposed KAON factory at TRIUMF (Tri-University Meson Facility) has been constructed. The chopper is an electric field device, driven by a tetrode-based pulser, for deflecting a charged particle beam. Associated with the tetrode used in the prototype design are high-voltage power supplies for the electrodes. The authors use an FET-based grid pulser and a sequencer capable of accurate digital control of pulse timing to 0.4 ns. A safety interlock and control system using a programmable controller with fiber-optic links has been built. This has given the versatility required in a prototype system.<>