Development of an H− ion source for the high intensity proton linac

Abstract

A volume production type negative ion source is under development for a high intensity proton linear accelerator. The source plasma is produced by an arc discharge using tungsten filaments. The cesium vapor was introduced into the plasma chamber by using an oven. The beam extractor consists of three electrodes with a single aperture of 8 mm in diameter. Negative ion current of 72 mA was achieved at the arc discharged power of 56 kW. The emittance measurement indicated that normalized emittances were 0.13 (horizontal plane) and 0.15 (vertical plane) π mm mrad at 70 keV and 60 mA.