“…For the energy measurement, ISS-CREAM uses a densified graphite block, which is equivalent to 0.5 nuclear interaction length, to initiate CR showers. The calorimeter (CAL) [7] then samples the shower using 20 alternating layers of tungsten plates and layers of ribbons of scintillating fibers. The scintillation light from the ribbons is guided to the instrument's light sensitive hybrid-photodiodes (HPDs), which convert the light signal to electrical pulses.…”