Characterisation of the high-energy proton Cherenkov response approaching the energy threshold for miniaturised space-borne detectors

The incorporation of silicon photomultipliers into Cherenkov detector systems offers a new standard for satellite programs, utilising the small volume and power draw of the devices to design setups that can be used in CubeSat missions. One such implementation proposed is that of a high-energy proton detector to monitor the flux of particles in low Earth and geostationary orbits. Of particular interest are protons produced in solar events with energy greater than 300 MeV that pose a threat to space missions, aircraft and ground-based infrastructure. A detector can utilise the inherent energy threshold of the Cherenkov light production mechanism to monitor the high-energy proton enhancement due to these solar energetic events, above the typical trapped proton and GCR levels in orbit. We present the development of a SiPM-based Cherenkov detector system and display its capability to discriminate between protons with energies around a given radiator's Cherenkov energy threshold.