Abstract
Cherenkov detectors have been used in space for decades to measure Galactic Cosmic Rays (GCRs), Solar Energetic Particles (SEPs) and trapped particles. We present proof‐of‐concept GRAS/Geant4 simulations to both show that a cubic fused silica Cherenkov detector with SiPM in LEO has a good sensitivity to SEP and GCR protons as a function of cut‐off rigidity and trapped protons in the South Atlantic Anomaly (SAA), and to characterize/mitigate the background that this detector would experience. We find that Cherenkov count rates due to most particle components vary significantly depending on many different factors, including the location in the orbit and solar particle event characteristics. We also investigate the use of coincidence as a method to remove background due to trapped electrons and delta electrons, finding this method is very effective for resolving count rates due to GLEs amongst intense trapped particle environments, but some Cherenkov count rates due to trapped particles are still observed in the simulated SAA region. Plain Language Summary Radiation in space near Earth is very complex, and varies with time as well as with location in Earth's magnetic field. Despite decades of research, there are still many unknowns about the composition, energy spectrum and time dependence of radiation near Earth, particularly during large solar events. In this research we investigate the feasibility of using small Cherenkov detectors for measuring the radiation environment around Earth. Recent advances in silicon photomultiplier technology have meant that small Cherenkov detectors can be made relatively cheaply, and be placed in orbit on small satellites. The simulation results presented in this paper show that small Cherenkov detectors should be capable of measure many interesting types of radiation in a low‐Earth orbit, with the energy spectra of particles trapped in Earth's radiation belts and particles during solar events being of particular interest. We anticipate that detectors of the design simulated here could be used in combination with ground based neutron monitors to increase our understanding of atmospheric radiation levels that aircraft experience during high‐energy solar events.