Abstract Short-pulse accelerator technology developed during the early 1960s through the late 1980s is being extended to high average power systems capable of use in industrial and environmental applications. Kilowatts to megawatts of beam power will be required for processes requiring high dose levels and/or high volume throughput systems. Accelerating potentials can range from less than 1 MV to as much as 10 MV depending on the type of beam, depth of penetration required, and the density of the product being treated. This paper addresses the status of a new family of high average power systems, with output beam power levels up to 300 kW, that use saturable core switches to achieve output pulse widths of 50 to 80 ns. Inductive adders and field emission cathodes are used to generate beams of electrons or X-rays at up to 2.5 MeV over areas of 1000 cm 2. Similar high average power technology is being used at ≤ 1 MeV to drive repetitive ion beam sources for treatment of material surfaces over 100s of cm 2.