The design and performance of CUBES — a CubeSat X-ray detector

Abstract CUBES is a X-ray detector payload which will be installed on the KTH 3U CubeSat mission, MIST. The comprises cerium-doped Gd 3 Al 2 Ga O 12 (GAGG) scintillators read out with silicon photomultipliers through Citiroc Application-Specific Integrated Circuit. operates in energy range ?35–800 keV. aim of mission to provide experience operation these relatively new technologies high-inclination low earth orbit, thereby providing confidence for component selection more complex satellite missions. design described, and results from performance characterisation tests carried prototype CUBES, called Proto-CUBES, are reported. Proto-CUBES was flown stratospheric balloon platform Timmins, Canada, August 2019. During ?12 hour long flight, studied near-space environment. As well as measuring counts spectra at different atmospheric depths, 511 keV line positron annihilation observed.