Silicon Detector R&D for the CSES missions and beyond

by Coralie Neubuser (Universita degli Studi di Trento & INFN)

Tuesday 15 Apr 2025, 16:15 → 17:15 Europe/Berlin

ENC-D308

The China Seismo-Electromagnetic Satellite (CSES) missions represent the forefront of space-based efforts to study the coupling between the ionosphere and lithosphere. Equipped with a diverse array of instruments, these missions can detect a broad range of perturbations in the ionosphere and magnetosphere, including transient electromagnetic emissions (e.g., from lightning) and long-duration particle injections resulting from space weather events. The first satellite was launched in August 2018, and in this presentation, I will highlight some of the key scientific findings obtained so far.

One of the principal instruments aboard CSES is the High-Energy Particle Detector (HEPD), which monitors electrons and protons with energy thresholds of 3 MeV and 30 MeV, respectively. The Limadou collaboration has developed an enhanced version of the HEPD for the second satellite in the CSES constellation, slated for launch in June 2025. A significant upgrade is the use of Monolithic Active Pixel Sensors (MAPS) for the tracker, a technology never previously used in space. Compared to conventional hybrid silicon microstrip technology, MAPS offer improved precision, robustness, easier control and readout, reduced costs, and less invasiveness. However, MAPS still face challenges, such as small size and higher power consumption. The HEPD-02 tracker will consist of 150 ALPIDE sensors, with a custom-designed operation mode and readout system tailored for space applications. The flight model of HEPD-02 underwent extensive test-beam campaigns in 2023, and I will present the first performance results from these tests.

In addition to the CSES missions, next-generation astroparticle spaceborne detectors require large-area, solid-state detectors capable of single-hit precision timing measurements. Currently, silicon microstrip detectors are the only viable technological option to meet the large-area coverage and stringent power consumption constraints required for space operations. I will provide an overview of the leading initiatives in this field, before introducing the ARCADIA project by INFN. ARCADIA is developing MAPS with an innovative sensor design that incorporates proprietary backside processing to enhance charge collection efficiency and timing performance across a wide range of operational and environmental conditions. The novel design aims to achieve extremely low power consumption — on the order of 10 mW cm^-2 or better — for low hit rates in space applications. Since the initial design phase, several new test-chip versions have been developed and tested, with a specific focus on applications requiring picosecond time resolution. Current efforts are focused on advancing this technology to meet the needs of a future gamma-ray telescope, for which a dedicated demonstrator is being designed and will undergo production in the next year.