Nanosecond MOSFET gun pulser for the CESR high intensity linac injector

A fast solid-state pulser (PFH) for the Cornell CESR linac injector system is described. Stripline-packaged high-voltage power MOSFET devices are arranged in a novel cascade output topology to achieve extremely low transition times. In the present CESR injector, the PFH driver outputs pulses of 3 nanoseconds FNHM and 20 amperes peak current through an Eimac Y-796 cathode-grid assembly. Recovery time is approximately 10 nsec. Advantages of the MOSFET pulser over its hard-tube predecessor include a substantial increase in peak beam current, an order-of-magnitude reduction of gun interpulse recovery time and precise control of the unequal output pulse amplitudes required for e/sup +/ vs e/sup /njection modes. Reduction of physical size permits collocating the pulser with the linac electron gun assembly to minimize transmission line artifacts arising from unavoidable impedance mismatch over the gun's bias range. Successful implementation of the MOSFET linac gun pulser is an initial step to a future CESR B-factory injector.<
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