Extensive single event effects tests were performed on a new generation, the R6 process, of radiation-hardened 600-volt and 250-volt power metal-oxide semiconductor fieldeffect transistors (MOSFETs) from International Rectifier using two different ions (Krypton and Xenon) at many different beam energies, Bragg Peak positions, and drain and gate biases. Results show that there is no worst-case test condition for single event burnout but positioning of the energy deposition is critical for single event gate rupture.