Extraction kickers and modulators for the Advanced Hydrotest Facility

In order to exploit the full potential of the Advanced Hydrotest Facility (AHF) facility to produce a time sequence of proton transmission radiographs throughout the dynamic event, a kicker/modulator for extraction from the 50 GeV ring that is capable of generating a string of 25 pulse pairs at arbitrary times within a total time duration of 100 microseconds or more is desired. The full range of desired pulse-train requirements cannot be met with the commonly used pulse-forming cables or networks (PFNs) switched with thyratrons. The preferred modulator design approach at present is a transformer voltage-adder concept with primary-side pulses formed with MOSFET-switched capacitors. This modulator will be a scale-up of an existing modulator that has been developed by Lawrence Livermore National Laboratory for use in DARHT, an electron induction accelerator facility at Los Alamos National Laboratory. Before the voltage-adder concept can be adopted for use in AHF, a working prototype that meets the AHF requirements for the pulse voltage, current, rise and fall time, and total pulse number must be built and tested. Additional requirements for pulse-to-pulse flattop height variation and baseline shift must also be met. A development and testing plan for the voltage-adder kicker modulator for AHF is described.