• 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.