Author: Ryne, R.D.
Paper Title Page
MOPWO062 A Parallel Multi-objective Differential Evolution Algorithm for Photoinjector Beam Dynamics Optimization 1031
  • J. Qiang, C.E. Mitchell, S. Paret, R.D. Ryne
    LBNL, Berkeley, California, USA
  • Y.X. Chao
    UCB, Berkeley, California, USA
  Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
In photoinjector design, there is growing interest in using multi-objective beam dynamics optimization to minimize the final transverse emittances and to maximize the final peak current of the beam. Most previous studies in this area were based on genetic algorithms. Recent progress in optimization suggests that the differential evolution algorithm could perform better in comparison to the genetic algorithm. In this paper, we propose a new parallel multi-objective optimizer based on the differential evolution algorithm for photoinjector beam dynamics optimization. We will discuss the numerical algorithm and some benchmark examples. This algorithm has the potential to significantly reduce the computation time required to reach the optimal Pareto solution.
TUPFI057 Muon Accelerators for the Next Generation of High Energy Physics Experiments 1475
  • M.A. Palmer, S. Brice, A.D. Bross, D.S. Denisov, E. Eichten, R.J. Lipton, D.V. Neuffer
    Fermilab, Batavia, USA
  • C.M. Ankenbrandt
    Muons. Inc., USA
  • S.A. Bogacz
    JLAB, Newport News, Virginia, USA
  • J.-P. Delahaye
    SLAC, Menlo Park, California, USA
  • P. Huber
    Virginia Polytechnic Institute and State University, Blacksburg, USA
  • D.M. Kaplan, P. Snopok
    Illinois Institute of Technology, Chicago, Illinois, USA
  • H.G. Kirk, R.B. Palmer
    BNL, Upton, Long Island, New York, USA
  • R.D. Ryne
    LBNL, Berkeley, California, USA
  Funding: Work supported by the U.S. Department of Energy and the U.S. National Science Foundation
Muon accelerator technology offers a unique and very promising avenue to a facility capable of producing high intensity muon beams for neutrino factory and multi-TeV lepton collider applications. The goal of the US Muon Accelerator Program is to provide an assessment, within the next 6 years, of the physics potential and technical feasibility of such a facility. This talk will describe the physics opportunities that are envisioned, along with the R&D efforts that are being undertaken to address key accelerator physics and technology questions.
TUPFI058 Simulation of Beam-induced Gas Plasma in High Gradient RF Field for Muon Colliders 1478
  • K. Yonehara, M. Chung, A.V. Tollestrup
    Fermilab, Batavia, USA
  • B.T. Freemire
    IIT, Chicago, Illinois, USA
  • R.P. Johnson, T.J. Roberts
    Muons. Inc., USA
  • R.D. Ryne
    LBNL, Berkeley, California, USA
  • V. Samulyak
    BNL, Upton, Long Island, New York, USA
  • K. Yu
    SBU, Stony Brook, USA
  There is a strong limit of available RF gradient in a vacuum RF cavity under magnetic fields because the magnetic field enhances a dark current density due to electron focusing and increases probability of an electric breakdown. This limits the cooling performance. A dense hydrogen gas filled RF cavity can break this limit because the gas acts as a buffer of dark current. However, RF power loading due to a beam-induced plasma in a dense gas filled RF cavity (plasma loading effect) is crucial to design the practical cavity. Experiment shows that the plasma loading can be mitigated in denser hydrogen gas and by doping a small amount of electronegative gas in the cavity. A complicate plasma chemical reaction should be dominated in such a dense hydrogen gas condition. A beam-induced plasma is simulated by taking into account the plasma chemistry to reproduce the condition by using the supercomputer at LBNL. We will also investigate the space charge effect in a dense gas in this effort.