Radiation detectors are an invaluable tool for space applications that span planetary science, astrophysics, heliophysics, and dosimetry for human exploration. A common technology used for radiation detection is the scintillator, where the material generates a light flash with an intensity that is proportional to the energy deposited by the incident radiation. For planetary science, the elementary composition can be determined down to a couple meters below the surface by measuring the emitted gamma rays produced from nuclear decay, proton inelastic scattering, or neutron interactions. The ambient galactic cosmic rays or trapped charged particles in a magnetosphere will scatter with nuclei in the planetary body generating neutrons, which interact with isotopes producing specific gamma rays. As a test case, a mission to Europa presents numerous challenges due to the high radiation environment because of its orbit in relationship to the trapped radiation in Jupiter’s magnetosphere as well as the extremely low temperature. Within this extreme environment, common scintillation materials will fail for numerous reasons. The light yields may be suppressed at the low temperatures, the material may darken due to radiation damage, or the response time of the light flash is too slow to handle the high event rates. There are some materials that function down to 70 K, yet the transient response is slow making it difficult to provide good gamma ray spectroscopy in a high radiation environment. New scintillation materials, which includes ceramics, provide promise for developing a nuclear instrument for planetary science that can function at low temperatures and high radiation environments. The goal of this project is to develop a high-performance scintillation material for deployment to the surface of Europa, where in the Phase 1 effort, candidate materials will be identified based on their low temperature performance.
Advanced scintillation materials serve a number of applications: