The CUBES experiment is proposed by Particle and Astroparticle Physics group, Dept. of Physics, KTH
Satellites in low earth orbit are subject to radiation in the form of charged cosmic rays, X-/gamma-rays and neutrons. The nature and intensity of the radiation varies with orbital altitude and position. For example, the Earth's magnetic field suppresses low energy particles at equatorial locations (so-called geomagnetic cut-off). In polar regions, satellites pass through belts of trapped charged particles. Significant transient changes in the incident flux are also possible due to solar activity and (at X-/gamma-ray energies) thunderstorm activity in the earth's atmosphere. The radiation environment encountered by satellites is complex and new mission proposals typically use computer models to assess potential measurement backgrounds to scientific instruments operated in space.
The goal of CUBES is to study the in-orbit radiation environment using a detector comprising a silicon photomultiplier coupled to scintillator material. The proposed components have been identified for use in future missions (e.g. the SPHiNX mission for hard X-ray polarization studies of gamma-ray bursts). Deployment on a CubeSat mission will provide valuable qualification data – especially for the ‘GAGG’ scintillator which has never been used in space. For the scintillators, studies will focus on possible radio-activation, induced fluorescence and radiation damage. Silicon photomultipliers are a relatively new technology with very limited space heritage. They are of great interest for future space missions due to operating properties comparable to a traditional photomultiplier tube but with significantly lower mass, insensitivity to magnetic fields and low voltage operation.