In-Beam Performance of the Super BigBite Spectrometer Hadron Calorimeter

The design and in-beam performance of a newly commissioned segmented sampling hadron calorimeter, HCAL-J, operating in Jefferson Laboratory's experimental Hall A will be presented. HCAL-J was designed to measure the energy of several GeV protons and neutrons. It is composed of 288 individual calorimeter modules measuring 15cmx15cmx1m and weighs approximately 40 tons total. Each module consists of 40 layers of iron, which cause the hadrons to shower, alternating with 40 layers of scintillator, which sample the energy. HCAL-J took its first electron beam data as part of the Super BigBite Spectrometer (SBS) nucleon form factor experiments during fall 2021 and winter 2022. The first of these experiments, G_Mⁿ, measured the magnetic form factor of the neutron with HCAL-J detecting hadrons quasi-elastically scattered from liquid deuterium in coincidence with electrons measured by the BigBite Spectrometer. HCAL-J's performance in timing resolution, position resolution, energy resolution, and detection efficiencies during this initial run period will be discussed.