Modulator development for the Next Generation Linear Collider

The Next Generation Linear Collider (NLC) represents a significant challenge for high voltage modulator technology. The 3000 X-band klystrons which provide the RF for the accelerator are designed for 500 kV, 265 A operation (>125 MW peak input power) for a period of 1-5 microseconds. Several technologies, ranging from traditional thyratron/PFN modulators to more exotic designs, have been proposed to meet the NLC technical requirements. With more than 1600 required modulators, factors in addition to acquisition cost must be considered for NLC. Small improvements in modulator efficiency, reliability, and maintainability have significant life cycle cost impacts. In 1999, Diversified Technologies, Inc. (DTI) was awarded three Small Business Innovative Research (SBIR) grants from the Department of Energy to assess these issues for solid state switching technology. These efforts are focused on two modulator configurations-a "hybrid modulator", using a solid state switch and a pulse transformer, and a 500 kV hard switch. The third SBIR is focused on development of low cost, high performance switching power supplies.