produced. The Dynamitron utilizes a cascaded rectifier system in which all rectifiers are driven in parallel from a high-frequency oscillator. For optimal insulation the high-voltage generator is contained in a pressurized tank filled with SF (sulfur hexafluoride) gas. The direct current from the rectifiers establishes a DC potential of up to about 5 MV. The monoenergetic electron beam thus developed is essentially of constant current. Energy and current determine the output capacity of an electron accelerator. For example, a 4-MeV beam of 25 mA will produce 100 kW of beam power. The manufacturer of the Dynamitron, Radiation Dynamics Inc. (Melville, NY), offers various models, such as 150 kW/ 3 MV, 200kW /4M V, and 100kW /5MV ( ). Higher voltage means greater depth of penetration; higher beam power means higher throughput of material to be irradiated. As shown schematically in Figure , the electron beam is rhythmically