Design and Performance Characteristics of the Zero Gradient Synchrotron (ZGS) H- Ion Source and Related Systems

An expression for the maximum H- current obtainable from an H+ beam by charge exchange in hydrogen has served as a guide in the design and development of a source of H- ions for booster injection into the ZGS. Here it is used as a criterion in the evaluation of testbench results obtained with the present test source. Space and power limitations in the 750-keV terminal of the preinjector have led to the use of titanium sublimation pumping to handle large instantaneous gas loads. Power limitations and the need for high pumping conductance have led to the substitution of electrostatic deflection for magnetic deflection in the beam separator.