Los Alamos High-Current Proton Siorage Ring; A Status Report

The Proton Storage Ring (PSR),1 whose installation was recently completed at Los Alamos, is a fast-cycling high-current accumulator designed to produce intense 800 MeV proton pulses for driving a spallation neutron source.2 The ring converts long beam pulses from the LAMPF linear accelerator into short bunches well matched to requirements of a high-resolution neutron-scattering materials science program. The initial performance goal for this program is to provide 100-μA average current at the neutron production target within a 12-Hz pulse rate. Project construction began in May 1982, and was completed in mid-April 1985. First beam was circulated in the ring on April 26. Operation at 20 μA is scheduled for September 1985, with full intensity within the next year. The storage ring was originally designed to function in a second mode in which six 1-ns bunches are accumulated and separately extracted every LAMPF macropulse. Implementation of this mode, which would serve a fast-neutron nuclear-physics program, has been deferred in favor of initial concentration on the neutron-scattering program. This paper summarizes the PSR design and status. Unique machine features include high peak current, two-step charge-stripping injection, a low-impedance buncher amplifier to counter beamloading, and a high-repetion-rate strip-line extraction kicker. LINE-A