Thyratron Replacement

Although the thyratrons used in klystron modulators for large accelerator projects function properly, they need replacement every 10,000 hours at a cost of $13,000 each, plus labor. Furthermore, periodic maintenance is required to adjust their reservoir heater voltage over the thyratron lifetime. Thyratrons are also becoming obsolete as fewer and fewer vendors are selling them in response to decreased demand. An alternate solid-state device, the insulated-gate bipolar transistor (IGBT), can readily operate at the speed needed for the accelerator, but commercial IGBTs cannot handle the voltage and current required. It is, however, possible to assemble these devices in arrays to reach the required performance levels without sacrificing their inherent speed. Diversified Technologies Inc. (DTI) has patented and refined the technology required to build these arrays of series- parallel connected switches. In Phase I, the small business will select potential candidate IGBTs, choose the optimal device(s) based on their price and performance in single- device tests, determine the gate drive performance necessary to allow high-current operation, and develop a multi-device switch plate. In Phase II the small business will develop the gate drive for the system, then design, build, and test a complete switch. One or more switches will be delivered to a national accelerator lab, and their performance and reliability will be tested in the facilities modulators. Commercial Applications and Other Benefits: The technology developed to enable a viable, solid- state thyratron replacement will find applications in the realm of conventional solid-state modulators. Higher current, very fast solid-state switches will have extensive applicability in kickers, Pulsed Electric Field (PEF) systems for food, wastewater, and biofuel treatment, electro- magnetic launch systems, and any other application requiring very high peak power.