Electromagnetic Calorimeter for the SPD Experiment

A prototype of a Shashlyk-type electromagnetic calorimeter for the reconstruction of photons and electrons in the SPD experiment was built. The module is assembled from 4 cells of size $$55 \times 55$$ cm2. The test setup included 4 modules and consisted of 16 cells placed as a $$4 \times 4$$ grid. The cells are made of 220 layers of scintillator and lead plates of widths 1.5 and 0.3 mm, respectively, and have a length of 12.6 radiation length and a Moliere radius of 3.2 cm. The energy and time resolutions of the calorimeter, obtained from cosmic ray testing, are shown. The energy resolution of the calorimeter prototype was measured to be 9.6% for MIP energy deposition of 240 MeV, and the time resolution for a single cell to be about 215 ps. Daily variations of the signal amplitude are within 0.5%.