Author: Baily, S.A.
Paper Title Page
MOEPPB012 High-performance Beam Simulator for the LANSCE Linac 103
  • X. Pang, S.A. Baily, L. Rybarcyk
    LANL, Los Alamos, New Mexico, USA
  Funding: U.S. Dept. of Energy, NNSA under contract DE-AC52-06NA25396.
The LANSCE accelerator complex is a multi-beam facility that provides high-intensity H+ and H particle beams for a variety of user programs. At the heart of the facility is a room temperature linac that is comprised of a 100-MeV drift tube linac and an 800-MeV coupled cavity linac. During beam operations, linac parameters are adjusted to maintain minimal beam spill, but without detailed knowledge of the beam distribution. A more desirable situation would be one where knowledge of the beam distribution along the linac is available to aid in the optimization of the linac operation and beam performance. We are presently developing a high performance simulator that will provide valuable information about the beam distribution in pseudo real-time during linac operations. The heart of the simulator is based upon the multiparticle beam dynamics code PARMILA, but implemented in C++ using NVIDIA’s CUDA technology for Graphics Processing unit (GPU) hardware. Linac operating set points will be provided by the EPICS control system so that changes are tracked and the simulation results updated automatically. Details regarding the approach, benefits and performance will be presented.
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.