Hades spectrometer-physics motivation and first tests of detectors

Abstract

Results of two beams tests of the full-size prototype of TOF module which will be used to for particle identification in the High Acceptance Di-Electron Spectrometer (HADES) are resented. HADES, a detector for spectroscopy of vector mesons in nuclear medium, is presently being built at GSI, Darmstadt, by a European collaboration involving groups from 10 countries. Group from NPI Řež in collaboration with other institutes prepared the TOF module consisting of 64 scintillator bars representing one sixth of the HADES outer time-of-flight system. During the tests using uranium beam from the SIS accelerator, GSI, in 1997 time resolution and other parameters of the TOF prototype were determined. Performance of the detector was stable during both tests. Time-of-flight distributions of charged particles produced in the reaction U+Pb at 1 A GeV was measured and compared with the QMD based simulation.