The beam test of lead tungstate calorimeter prototype with novel SiPM matrix readout at Jefferson Lab

The lead tungstate crystals are well-known radiator material for precise homogeneous electromagnetic calorimetry. In experimental nuclear physics, the typical way to read out the crystals is using conventional photomultiplier tubes (PMTs). If a magnetic field is present such a method has complications and requires a passive PMT shielding design. However, in the case of a strong field use of a PMT is almost impossible. The recent development of Silicon Photomultipliers (SiPMs) with small pixel pitch sizes and relatively small noise levels presents an alternative to conventional PMTs. The SiPM-based readout is currently considered for the instrumentation of lead tungstate calorimeters for future nuclear physics and collider experiments. We present the beam test results of a 3x3 calorimeter prototype instrumented with SiPM readout performed at Jefferson Lab. The SiPM readout performance was compared with the PMT readout measured in the same experimental conditions. The prototype was successfully tested using a beam of photons in the energy range between (2.5--11.5) GeV in experimental Hall D. The detector performance was also studied using a secondary beam of positrons provided by the Hall D pair spectrometer.