Thyratron-PFN, IGBT hybrid, and direct switched modulator R&D as it effects klystron protection

Modulator development is an ongoing program at SLAC. The Stanford Linear Accelerator with its approximately 240 klystrons and modulators operates for 6000 plus hours a year. This operation gives SLAC an important insight into component and system reliability in the high voltage environment. The planned NLC is approximately 10 times the size of SLAC and the high voltage modulator klystron systems are one of the largest cost drivers. This paper contains a brief progress report on the optimized line modulator and touches on solid-state advances, which make solid-state, high-power pulse modulators the wave of the future. Klystron protection remains a critical issue along with modulator reliability, efficiency and cost. Configurations whereby multiple klystrons are paralleled on a single modulator may exacerbate the problem. The majority of this paper discusses tests at SLAC of klystron arcs on line-type modulators with single and double klystron loads. This talk may introduce and refer to other talks at this conference and other conferences by national and foreign laboratory collaborators and industry, specifically in relation to DOE SBIR programs.