Intense negative heavy ion source with cusp magnetic field

The performance and the characteristics of the cusp-magnetic-field negative heavy-ion source which has been recently developed at KEK are described. After the first successful experiment to produce intense Cu, Ni, Au, and O negative ions with pulsed beams, an effort has been made to extract various species of negative ions such as Ag, Pt, C, Si, Bi Fe, Al, Ta, W, P, As, Cr, Ti, Co, Sn, In, V, and Pd from this ion source. Large intensities of the beam current ranging to more than milliamperes were obtained for almost all of these species. The beam intensities from this ion source were found to be almost 50-100 times larger than those from the ordinary cesium sputtered negative ion source. Beam emittance was also measured for the Ni beam, and the 90% normalized emittance was about 37 p mm-mrad-(MeV)/sup 1/2/.<>