Author/Authors :
Altarev، نويسنده , , I. and Schilling، نويسنده , , E. and Baunack، نويسنده , , S. and Capozza، نويسنده , , L. and Diefenbach، نويسنده , , J. W. Grimm، نويسنده , , K. and Hammel، نويسنده , , T. and von Harrach، نويسنده , , D. and Imai، نويسنده , , Y. and Kabuك، نويسنده , , E.M. and Kothe، نويسنده , , R. and Lee، نويسنده , , J.H. and Lopes Ginja، نويسنده , , A. and Maas، نويسنده , , F.E. and Sanchez Lorente، نويسنده , , A. and Steph، نويسنده ,
Abstract :
We present a new powerful liquid hydrogen target developed for the precise study of parity violating electron scattering on hydrogen and deuterium. This target has been designed to have minimal target density fluctuations under the heat load of a 20 μ A CW 854.3 MeV electron beam without rastering the electron beam. The target cell has a wide aperture for scattered electrons and is axially symmetric around the beam axis. The construction is optimized to intensify heat exchange by a transverse turbulent mixing in the hydrogen stream, which is directed along the electron beam. The target is constructed as a closed loop circulating system cooled by a helium refrigerator. It is operated by a tangential mechanical pump with an optional natural convection mode. The cooling system supports removal of up to 250 W of beam heating removal. Deeply subcooled liquid hydrogen is used to keep the in-beam temperature below the boiling point. The target density fluctuations are found to be at the level of 10 - 3 at a beam current of 20 μ A .
Keywords :
Charge conjugation , PARITY , time reversal , Particle sources and targets , Polarized and other targets , Other discrete symmetries
