Novel Switching Devices for Accelerator Modulatros

This project addresses very high power switches for accelerators used in high-energy physics research and particle research. Existing devices have relatively slow switching times, compared to those required for the application. The proposed program seeks to develop high-voltage, high-current devices with much faster switching times and reduced conduction losses, thereby also improving reliability. Two approaches are utilized here. The first is to develop switches operating at very low (cryogenic) temperatures, and the second is to apply proprietary switching topologies to this application. In Phase I, a cryogenic drive system was developed, and two cryogenic power modules were demonstrated in a liquid nitrogen bath at 6000 volts and 240 amperes, switching single, megawatt-level pulses. The switching times of one module improved by almost 6 times over room-temperature operation, and the on-state voltage of the other improved by up to 20 times. In the Phase II program, prototype high-voltage, high-current switches (rated for operation at 6000 volts and 2000 amperes) will be developed and tested extensively under a variety of loads, pulse durations, operation times, and power levels. Reliability and current slew rate will also be evaluated. The modules will be designed for room-temperature operation as well. Commercial Applications and Other Benefits: Apart from accelerator applications, which could lead to major breakthroughs in the understanding of fundamental physical phenomena, the high-power switches developed in this program could find use in power distribution systems for existing or future power grids (for example, superconducting transmission lines and superconducting wind turbines), as well as medical and military applications.