Development of solid-state induction modulators for high PRF accelerators

Lawrence Livermore National Laboratory (LLNL) and EG&G Energy Measurements are developing a new solid-state power system for two proposed accelerators. One of the accelerators is a circular arrangement of induction cells called a recirculator for accelerating heavy ions for inertial fusion, the other is a linear induction accelerator for electron beams called the Advanced Radiographic Machine (ARM). The need for complex pulse agility in these accelerators led us to examine solid-state switching components that have an on/off capability. The intrinsic speed of solid-state switching satisfies our high PRF requirements, while the on/off switching action of some semiconductor devices enables us to select an arbitrary pulse width. To accommodate these requirements, we selected field effect transistors (FETs) as the preferred switching elements. The same FET switching technology applies to both accelerators due to their similar pulse requirements. For our research, two full-scale prototypes were built-a 5 kV induction recirculator cell and a single 15 kV induction modulator for the ARM accelerator. We discuss the general network features that are common to both machines, followed by performance and modeling data.