Cooling channels were engraved on the reverse side of the cathode flow-field plate, given the predominant heat generated during oxygen reduction reactions (ORR). Gas and coolant tightness was ensured by 1.2-mm thick EPDM gaskets, facilitating appropriate MEA compression. Sheathed in PVC tubing, 12 bolts were positioned along the endplate periphery. Uniform compression was achieved by incrementally increasing torque to 6 N m. Gases and coolant were both supplied from the anode endplate side to make the fuel cell position close to the neutron scintillator of the CMOS camera box.