MeVCube -- A novel Compton imaging gamma-ray camera for astrophysics and terrestrial applications

• Applicants: Dr. Markus Ackermann; Professor Dr. David Berge
• Subject Area: Astrophysics and Astronomy
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 448812190

The measurement of gamma-ray emission from astrophysical sources has revolutionized our understanding of high-energy processes in the universe. In gamma-ray astronomy the energy range between a few hundred keV and a few MeV is the least explored, even though it holds key information to non-thermal processes and environments around compact objects like colliding neutron stars or active galactic nuclei. In particular in the context of multi-messenger astronomy, which combines measurements of electromagnetic radiation of the same objects or events with gravitational waves and neutrinos, this energy range provides crucial information for identifying the connection between these observations.Astronomy in the MeV range can only be performed from space, as the atmosphere absorbs gamma rays efficiently. This is one of the reasons why the MeV energy range is relatively poorly explored, satellite costs used to be often unaffordably large. The ascent of CubeSats, small standardized satellite payloads that are launched alongside larger satellites, has now opened a game-changing opportunity for MeV astronomy. A compact, low-power imaging gamma-ray detector on such a CubeSat can reach an order of magnitude higher sensitivities than previous large-scale instruments at one to two orders of magnitude lower cost.In this joint Joint Sino-German Research Project we propose to develop such a compact low-power imaging gamma-ray detector as a technology demonstrator for future CubeSat missions. The detector works as a Compton camera, using the physics of Compton scattering to determine the incident gamma-ray direction. Using state-of-the-art, custom-designed semiconductor detectors and readout electronics we propose to develop and build the MeVCube detector for the energy range between 250~keV and 5~MeV with an angular resolution below 1.5~deg at 1 MeV. MeVCube will be less than 10~cm x 10~cm x 10~cm in size and will use only about 2~W of power. The performance of this Compton camera will then be fully qualified with respect to a future use in a CubeSat mission.Such an MeV gamma-ray detector is not only interesting for astronomy, but also in radiation monitoring and for medical applications. While off-the-shelf solutions exists for some of the latter applications, the detector proposed here is lighter, more compact and has a lower power consumption than these solutions. Therefore qualifying the performance and innovation potential of our Compton camera for such terrestrial applications is the second important aspect of this proposal.

• DFG Programme: Research Grants
• International Connection: China
• Major Instrumentation: CdZnTe sensors
• Instrumentation Group: 0260 Strahlungsmeßplätze (außer 033, 330-339, 405 und 615-619)
• Partner Organisation: National Natural Science Foundation of China
• Co-Investigators: Dr. Ingo Bloch; Dr. Jian Li
• Cooperation Partners: Peng Wen-Xi; Professor Dr. Wan-Chang Zhang