This paper will focus on next-generation inorganic scintillation detectors that could be used to study neutral emission from the high-energy Sun. Recent developments in detector technology have yielded candidate materials for future heliophysics missions, namely elpasolites (Cs2LiYCl6:Ce – CLYC and Cs2LiLaBr6:Ce – CLLB). At a modest cost, these detectors yield superior spectroscopic performance compared to previously used materials (NaI:Tl and CsI:Tl). Additionally, elpasolites can detect and measure thermal to fast (<10 MeV) neutrons, simultaneously with γ rays. In the following sections, we discuss: the importance for measuring neutral emission from the Sun, laboratory performance of candidate scintillators and novel light readout devices, a proposed instrument concept, and the expected response to a γ-ray line-producing and neutron-producing solar flares from the vantage points of 1 AU, 0.3 AU, and 0.04 AU.
The SIRI line of instruments is designed to space-qualify new space-based, gamma-ray detector technology for Department of Defense (DoD) and astrophysics applications. SIRI-2’s primary objective is to demonstrate the performance of europium-doped strontium iodide (SrI2:Eu) gamma-ray detection technology with sufficient active area for DoD operational needs. Secondary scientific objectives include understanding the internal background of SrI2:Eu in the space radiation environment, and studying transient phenomena, such as solar flares. The primary detector array of the SIRI instrument consists of seven hexagonal europium-doped strontium iodide (SrI2:Eu) scintillation detectors 3.81 cm by 3.81 cm, with a combined active area of 66 cm2. SIRI-2’s primary detectors have an energy resolution of ~4% at 662 keV. SIRI-2 is expected to operate in the high gamma-ray background of a geosynchronous orbit and the instrument includes a number of features to both passively and actively suppress the unique background of the outer Van Allen belts. Construction and environmental testing of the SIRI-2 instrument has been completed, and it is currently awaiting integration onto the spacecraft bus. The expected launch date is Aug 2020 onboard the Space Test Program’s STPSat-6.
Conference Committee Involvement (2)
Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXIII
1 August 2021 | San Diego, California, United States
Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXII
25 August 2020 | Online Only, California, United States