Author: Torrez, P.A.
Paper Title Page
THPPP097 Diagnostic Pulse for Single-particle-like Beam Position Measurements During Accumulation/Production Mode in the Los Alamos Proton Storage Ring 3960
  • J.S. Kolski, S.A. Baily, E. Björklund, G.O. Bolme, M.J. Hall, S. Kwon, M.P. Martinez, M.S. Prokop, F.E. Shelley, P.A. Torrez
    LANL, Los Alamos, New Mexico, USA
  Beam position monitors (BPMs) are the primary diagnostic in the Los Alamos Proton Storage Ring (PSR). Injecting one turn, the transverse motion is approximated as a single particle with initial betatron position and angle (x0 and x0'). With single-turn injection, we fit the betatron tune, closed orbit (CO), and injection offset (x0 and x0' at the injection point) to the turn-by-turn beam position. In production mode, we accumulate multiple turns, the transverse phase space fills after 5 injections (horizontal and vertical fractional betatron tunes ~0.2) resulting in no coherent betatron motion, and only the CO may be measured. The injection offset, which determines the accumulated beam size and is very sensitive to steering upstream of the ring, is not measurable in production mode. We describe our approach and ongoing efforts to measure the injection offset during production mode by injecting a ‘‘diagnostic'' pulse ~50 us after the accumulated beam is extracted. We also study the effects of increasing the linac RF gate length to accommodate the diagnostic pulse on the production beam position, transverse size, and loss.