Beam tests of the ZEUS barrel calorimeter

A fully compensating uranium‐scintillator calorimeter with specially designed electronic readout was constructed for the ZEUS detector at HERA. The Barrel part of the calorimeter and the readout electronics for the entire calorimeter were built by the US collaboration. During two running periods in the summers of 1990 and 1991, some of these modules were subjected to beam tests at Fermilab before shipping to DESY for installation. These tests were primarily aimed at calibrating the modules with electrons and hadrons, measuring cell response uniformity and resolutions. Results from these runs show that tower‐to‐tower and module‐to‐module uniformities are better than 1% using both muon and electron, energy resolutions are 35%/ √E for hadrons and 19%/ √E for electrons, energy nonlinearity is less than 1% for both electron and hadron, the absolute calibration and the equality of response for electrons and hadrons are confirmed to 2%.