• K.T. McDonald
  PU, Princeton, New Jersey
• J.R.J. Bennett
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• O. Caretta, P. Loveridge
  STFC/RAL, Chilton, Didcot, Oxon
• A.J. Carroll, V.B. Graves, P.T. Spampinato
  ORNL, Oak Ridge, Tennessee
• I. Efthymiopoulos, F. Haug, J. Lettry, M. Palm, H. Pereira
  CERN, Geneva
• A. Fabich
  EBG MedAustron, Wr. Neustadt
• H.G. Kirk, H. Park, T. Tsang
  BNL, Upton, Long Island, New York
• N.V. Mokhov, S.I. Striganov
  Fermilab, Batavia
• P.H. Titus
  PPPL, Princeton, New Jersey

We report on the analysis of data collected in the MERIT experiment at CERN during the Fall of 2007. These results validate the concept of a free mercury jet inside a high-field solenoid magnet as a target for a pulsed proton beam of 4-MW power, as needed for a future Muon Collider and/or Neutrino Factory.

• T.R. Edgecock
  STFC/RAL, Chilton, Didcot, Oxon
• J.J. Back
  University of Warwick, Coventry
• J.R.J. Bennett
  STFC/RAL/ISIS, Chilton, Didcot, Oxon
• C.N. Booth, G.P. Skoro
  Sheffield University, Sheffield
• S.J. Brooks
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon

The UK programme of high power target developments for a Neutrino Factory is centred on the study of high-Z materials (tungsten, tantalum). A description of lifetime shock tests on candidate materials is given as part of the research into a solid target solution. A fast high current pulse is applied to a thin wire of the sample material and the lifetime measured from the number of pulses before failure. These measurements are made at temperatures up to ~2000 K. The stress on the wire is calculated using the LS-DYNA code and compared to the stress expected in the real Neutrino Factory target. It has been found that tantalum is too weak to sustain prolonged stress at these temperatures but a tungsten wire has reached over 26 million pulses (equivalent to more than ten years of operation at the Neutrino Factory). An account is given of the optimisation of secondary pion production from the target and the issues related to mounting the target in the muon capture solenoid and target station are discussed.

• G.P. Skoro, C.N. Booth
  Sheffield University, Sheffield
• J.J. Back
  University of Warwick, Coventry
• J.R.J. Bennett, S.A. Gray, A.J. McFarland
  STFC/RAL/ISIS, Chilton, Didcot, Oxon
• T.R. Edgecock
  STFC/RAL, Chilton, Didcot, Oxon

Recently reported results on the tungsten lifetime/fatigue tests under conditions expected in the Neutrino Factory target have strengthened the case of solid target option for a Neutrino Factory. This paper gives description of the detailed measurements of the tungsten properties at high temperature and high stress. We have performed extensive set of measurements of the surface displacement and velocity of the tungsten wires that were stressed by passing a fast, high current pulse through a thin sample. Radial and longitudinal oscillations of the wire were measured by a Laser Doppler Vibrometer. The wire was operated at temperatures of 300-2500 K by adjusting the pulse repetition rate. In doing so we have tried to simulate the conditions (high stress and temperature) expected at the Neutrino Factory. Most important result of this study is an experimental confirmation that strength of tungsten remains high at high temperature and high stress. The experimental results have been found to agree very well with LS-DYNA modelling results.