CALIBRATION AND PERFORMANCE OF THE CHARM-II DETECTOR CHARM-II COLLABORATION

The neutrino detector CHARM-II at CERN, consisting of a large target calorimeter equipped with streamer tubes and a muon spectrometer, has been exposed to a test beam of electrons, pions and muons with momenta between 2 and 60 GeV/c in order to study the digital response of the streamer tubes, the analog response of the pickup strips and the momentum resolution of the muon spectrometer. Methods have been developed to carry the calibration results in space from the impact point of the test beam to the bulk of the detector and in time from the test beam period to all the data taking periods between 1987 and 1991, The number of hits along muon tracks was used to parametrize the dependence on fluctuations of temperature, tube voltage and gas composition. Curves and formulae are presented showing the energy response and the energy resolution for the different beam particles. The test beam data have been used to optimize and calibrate algorithms for the kinematical reconstruction of electron showers and for their extraction from the vast background of hadronic showers.