Beam simulations for the H{sup {minus}} upgrade at LANSCE

An upgrade program is being carried out at Los Alamos to increase the peak beam current from the present H{sup {minus}} injector to provide 200 {mu}A average current for the proton storage ring at LANSCE. In order to meet this objective, the injector must provide at least 30% more current than presently available. More optimal operation however, requires a factor of two higher peak current in order to reduce circulating losses in the ring. At these higher currents, a lower beam emittance is needed to limit beam losses in the linac. Beam simulations have been carried out to model the operation of the present injector and to determine what changes will be required to operate with these higher beam currents. A collaboration with the Lawrence Berkeley National Laboratory (LBNL) is now in progress to modify the present converter ion source to produce 40-mA peak of H{sup {minus}} beam current with reduced beam emittance. Beam simulations show that a new 80-kV accelerating column will be needed to accelerate and transport these higher current beams with acceptable beam size and divergence. Experimental results for the initial phase of this program are presented together with a comparison to these beam simulations.