Development of semiconductor regulation of capacitor charge for a compact high power ion beam source

A new power supplier for high power ion sources has been developed with using the Insulated-Gate Bipolar Transistor (IGBT) switching units, where the capacitor banks are employed as the electric power storage. This can make the supplier more compact and cheaper than that of usual beam sources, though the output is 10 ms order of duration. The designed maximum beam power is 1 MW for 10 ms and the repetition time is 5 min so as to avoid the heat problem of the electrodes. One switching unit consists of parallel and serial IGBT elements which can be simultaneously driven by a set of photo pulses via each optical fiber. The dummy local test gives the rise time 4 μs and the rear edge fall-down 125 μs on the switching speed of 44 IGBT elements with the applied voltage 25 keV. As for the power test of another switching unit of 26 IGBT elements and 15 kV voltage for the acceleration source the power of 650 kW is obtained in this circuit. Using the medium-size backet ion source constructed, the extracted ion beam power of 40 kW is attained at present. Also, the arcing control and the electrode aging are found to be sufficiently achieved by the inter-lock system in our developed circuit. (author)