Study of characteristics of the BELLE CsI calorimeter prototype with a BINP tagged photon beam

Results of the test of the BELLE barrel calorimeter prototype using a tagged photon beam are presented. The prototype consisted of 36 CsI(Tl) counters with the same preamplifiers and shapers as in the BELLE calorimeter. The measurements were carried out at the VEPP-4M collider with the tagged photon beam provided by the ROKK-1M facility. The energy resolution for photons was measured in the energy range 40–800 MeV. The achieved energy resolution was 3% for 40 MeV and 1.5% for 800 MeV photons. The results are consistent with the Monte Carlo simulation taking into account effects of the electronics noise.