The EMCal is a lead-scintillator sampling calorimeter with large acceptance (110 degrees azimuthal, from -0.7 to 0.7 on pseudorapidity) comprising almost 13,000 individual towers that are grouped into ten super-modules. The towers are read out by wavelength-shifting optical fibers in a shashlik geometry coupled to avalanche photodiodes. The complete EMCal contains 100,000 individual scintillator tiles and 185 kilometers of optical fiber. EMCal weighs in total about 100 tons. It is an apparatus able to measure the energy of the particles, in particular of photons and electrons.
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