Despite the impressive progress achieved both by X-ray and gamma-ray observatories in the last few decades, the energy range between 200 keV and 50 MeV remains poorly explored. COMPTEL, on-board the Compton Gamma-Ray Observatory (CGRO, 1991-2000), opened the MeV gamma-ray band as a new window to astronomy, performing the first all-sky survey in the energy range from 0.75 to 30 MeV. More than 20 years after the de-orbit of CGRO, no successor mission is yet operating. Over the past years many concepts have been proposed like, for example, AMEGO, Astrogam, ETCC, GECCO and COSI.
MeVCube is a novel concept for a compact Compton telescope based on the CubeSat standard, with the advantages of small cost and relatively short development time. The scientific payload is based on two layers of pixelated Cadmium-Zinc-Telluride (CdZnTe or CZT) detectors, coupled with low-power read-out electronics (ASIC, VATA450.3). The performance of the read-out electronics and CdZnTe custom designed detectors have been measured extensively, meeting the requirements for the mission. The performance of the full telescope is accessed through simulations: despite a small effective area limited to a few cm^2, MeVCube can reach an angular resolution of 1.5 degrees, a field-of-view around 2sr, and a sensitivity comparable to the one achieved by the last generation of large-scale satellites like COMPTEL and INTEGRAL.
Cosimo Nigro, César Jesús-Valls, Jan Ollé