Author: Plostinar, D.C.
Paper Title Page
WEPEA073 A 180 MeV Injection Upgrade Design for the ISIS Synchrotron 2678
  • J.W.G. Thomason, D.J. Adams, B.S. Drumm, D.J.S. Findlay, I.S.K. Gardner, M.C. Hughes, S.J.S. Jago, B. Jones, R.J. Mathieson, S.J. Payne, B.G. Pine, A. Seville, H. V. Smith, C.M. Warsop, R.E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • D.C. Plostinar, C.R. Prior, G.H. Rees
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Obsolescence and reliability issues are motivating plans to replace the present 70 MeV H minus linac, and this paper presents an overview of a design to allow injection of beam into the present ISIS ring at 180 MeV, which would increase intensity as a result of reduced space charge and optimised injection. The key topics addressed are design of the injection straight, injection painting and dynamics, foil specifications, acceleration dynamics, transverse space charge, instabilities, RF beam loading and activation.  
THPWO086 Status of the RAL Front End Test Stand 3963
  • A.P. Letchford, M.A. Clarke-Gayther, D.C. Faircloth, S.R. Lawrie
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • S.M.H. Alsari, M. Aslaninejad, J.K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • J.J. Back
    University of Warwick, Coventry, United Kingdom
  • G.E. Boorman, A. Bosco, S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
  • R.T.P. D'Arcy, S. Jolly
    UCL, London, United Kingdom
  • C. Gabor, D.C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  The Front End Test Stand (FETS) under construction at RAL is a demonstrator for the front end systems of a future high power proton linac. Possible applications include a linac upgrade for the ISIS spallation neutron source, new future neutron sources, accelerator driven sub-critical systems, a neutrino factory etc. Designed to deliver a 60mA H-minus beam at 3MeV with a 10% duty factor, FETS consists of a high brightness ion source, magnetic low energy beam transport (LEBT), 4-vane 324MHz radio frequency quadrupole, medium energy beam transport (MEBT) containing a high speed beam chopper and non-destructive photo-detachment diagnostics. This paper describes the current status of the project and future plans.  
THPWO087 Measurement of Resonant Space Charge Effects in the J-PARC Linac 3966
  • D.C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • M. Ikegami
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • Y. Liu, T. Maruta
    KEK/JAEA, Ibaraki-Ken, Japan
  Traditionally, high intensity linac designs follow the “equipartitioning condition”, a strict control of the transverse and longitudinal tune ratios throughout the linac that ensures space-charge driven emittance exchange between the longitudinal and transverse planes is minimised. However, equipartitioning imposes strict rules on the linac design, thus limiting the design options and increasing the overall construction cost. More recently, practical tools have been developed that offer guidelines in designing non-equipartitioned linacs, by charting the stable regions in a tune ratio diagram (Hofmann’s Charts). While these stability diagrams have been backed by extensive multiparticle simulations and some experimental evidence, questions still remain regarding the practical consequences of crossing the resonances. In this paper preliminary results are presented from an experimental study conducted in the J-PARC linac, where for the first time we measured both the transverse and longitudinal emittance for different linac working points. A detailed analysis will be presented as well as a discussion on the wider implications of this experiment.