Ben Clewer

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.

Historically, gathering data on atmospheric radiation levels during solar particle events (SPEs) has been difficult, as there is little or no time warning of events. Being able to accurately quantify radiation levels within the atmosphere during solar events is of significance to the aviation industry, as described in the International Civil Aviation Organization's (ICAO) Space Weather manual, particularly during a large Ground Level Enhancement (GLE) where the ionising dose to passengers and crew can exceed the recommended general public annual dose limits, set by the International Commission for Radiological Protection (ICRP) Barlett, Beck, Bilski, Bottollier‐Depois, and Lindborg (2004), in one flight. The Smart Atmospheric Ionising RAdiation (SAIRA) Monitoring Network is a new system of handheld radiation detectors that can be carried on aircraft to monitor and record atmospheric radiation levels. The system operates via citizen science volunteers, who record radiation data as they travel for normal purposes. Over 30 flights have been conducted with volunteers to demonstrate that a citizen science network is possible. Volunteers have used a new Android application to record and upload data to a central server to form a database of flight measurements. The demonstration has shown there is a willingness in public volunteers to use radiation detectors and engage in science outreach. A fully developed system will ideally provide the capability to quantify radiation levels during a Solar Particle Event (SPE) or GLE and the data can be used by relevant organisations to minimise potential risks.