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⁺ vs eⁿjection 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