• P. Hodgson, C.N. Booth, P.J. Smith
  Sheffield University, Sheffield

The MICE experiment requires a beam of low energy muons to demonstrate muon cooling. A target mechanism has been developed that inserts a small titanium target into the circulating ISIS beam during the last 2ms before extraction. The target mechanism has been in operation in the ISIS beam during 2009 and a large set of useful data has been obtained describing the target's operational parameters. This has allowed the commissioning of the initial section of the MICE beam line and instrumentation, and the close monitoring of target performance. This work describes these target parameters and presents some of the results from operational shifts.

• P. Hodgson, C.N. Booth, P.J. Smith
  Sheffield University, Sheffield
• J.S. Tarrant
  STFC/RAL, Chilton, Didcot, Oxon

The MICE experiment uses a beam of low energy muons to test the feasibility of ionisation cooling. This beam is derived parasitically from the ISIS accelerator at the Rutherford Appleton Laboratory. A target mechanism has been developed and deployed that rapidly inserts a small titanium target into the circulating proton beam immediately prior to extraction without undue disturbance of the primary ISIS beam. The first target drive was installed in ISIS during 2008 and operated successfully for over 100,000 pulses. A second upgraded design was installed in 2009 and is currently in operation. The technical specification for this upgraded design is given and the motivation for many of the improvements is discussed. In addition possible future improvements to the current design are discussed.

• 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.