Cosmic tests of Cherenkov Electromagnetic Calorimeter for the HADES experiment

Cherenkov Electromagnetic Calorimeter (ECAL) was recently installed to complement the dilepton spectrometer HADES currently operating at SIS18 accelerator (GSI, Darmstadt, Germany). ECAL will be used to measure the meson and photon production in heavy ion collisions at the beam energy range of 1–10 A GeV. The calorimeter will also improve the electron–hadron separation. ECAL covers forward polar angles 16°<θ<45° and almost full azimuthal angle of the HADES acceptance. ECAL consists of 978 modules divided into 6 sectors. Each module consists of a lead glass Cherenkov block with light readout by a photomultiplier. The test bench to measure the light output of the ECAL modules from the cosmic muons and “in-situ” measurements at HADES are discussed. The relative energy resolution for cosmic muons was estimated during the tests.