PPPS-2013: Abstract submission anode modulation of high power RF output triodes of the ISIS LINAC

The ISIS Linear Accelerator at Rutherford Appleton Laboratory (RAL) has provided acceleration of H^- ions since 1984. ISIS has recently replaced the first pair of legacy, low power cathode modulators used on its 2 MW RF triodes with high power, solid-state anode modulators. The key to these new modulators is a series IGBT high voltage switch, rated at up to 40 kV, 300A, built by Diversified Technologies, Inc. This new modulator has eliminated a number of operating difficulties, and yielded significant savings with regard to operational downtime and ~25% energy consumption. These advantages benefit ISIS by improving reliability and availability, and ensuring RAL´s push towards an increased proton beam current above 200 μA can be achieved.