A transition radiation detector for kaon/pion separation

Abstract The experiment WA69 at the CERN Omega spectrometer facility has studied fixed target photon and hadron production of inclusive hadronic final states with tagged photon beams of 65–175 GeV in comparison to charged hadron beams (π and K) of 80 and 140 GeV fixed energies. For the identification of final state pions and kaons above 100 GeV/c a transition radiation detector (TRAD) has been developed. This detector was constructed of 12 modules, each consisting of a polypropylene fibre radiator and a proportional chamber with a xenon/methane gas mixture to detect the transition radiation produced by fast moving charged particles. We give a description of the detector setup and working conditions. As a first result obtained with the TRAD the ratio of photoproduced kaons and pions in the extreme forward regime ( x F > 0.7 and − t 2 ) is measured to be 10.2(±1.7)% which is in agreement with VDM predictions.