LAMPF Dual-Energy Operation

The Los Alamos Meson Physics Facility (LAMPF) operated with simultaneous H+ and H- beams until June 1980, when a method of providing a variable energy H- beam as well as a full-energy H+ beam was brought into use. The scheme is based on time sharing between H+ and H- beam pulses. It is now possible to provide H- beams with energy as low as 300 MeV along with the usual 800-MeV H+ beams. The method requires a reduction in duty factor of the H+ and H- beams; however, the total duty factor has been increased to 9% which compensates in large measure for the reduction due to dual-energy operation. The necessary modifications to the beam switchyard and accelerator timing systems are described.