The HERA-B electromagnetic calorimeter

We present test results on the HERA-B electromagnetic calorimeter modules. The module design exploits the “shashlik” technology of the light readout by means of wavelength shifting fibers. Results of R&D on the calorimeter inner section including radiation tests of module parts (scintillator, WLS fibers and PMs), measurements of scintillator-fiber light yield and tests of the module prototype at the electron beam are presented. For the modules of the middle section we present results on energy and position resolution measured with electrons in the momentum range 1–5 GeV/c. The response uniformity and cell-to-cell reproducibility have been studied with MIP at the ITEP accelerator. Results of beam tests are compared with a Monte Carlo simulation.