The purpose of the MPD experiment at NICA is to study dense baryonic matter, and the facility is now under construction. The operating energy range at the MPD is 4–11 AGeV. One of the MPD detectors is the forward hadron calorimeter (FHCal), which is designed to study the collisions geometry, primarily, the orientation of the reaction plane and the centrality of heavy ion collisions. The detector will measure energies of spectators (non-interacting nucleons).
The MPD experiment implements two calorimeters with holes in the center for the beam pipe. Each calorimeter consists of 44 individual modules, which are symmetrically located concerning a collision point. Each of the 44 modules consists of 42 lead/scintillator layers, each sized 15×15 cm2. The light from the scintillators is collected by wavelength shifting fibres (WLS) and then detected by silicon photomultipliers (SiPM) placed in the rear side of the module. The design, parameters and the energy calibration will be discussed.