Solid Target for a Neutrino Factory

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 a 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 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). Mea­sure­ments of the sur­face ve­loc­i­ty of the wire using a laser in­ter­fer­om­e­try sys­tem (VISAR) are in progress, which, com­bined with LS-DY­NA mod­elling, will allow the eval­u­a­tion of the con­sti­tu­tive equa­tions of the ma­te­ri­al. An ac­count is given of the op­ti­mi­sa­tion of sec­ondary pion pro­duc­tion and cap­ture in a Neu­tri­no Fac­to­ry and of the lat­est solid tar­get en­gi­neer­ing ideas.