Severe Space Weather Satellite Protection

ABSTRACT: Modern electronics used for military space communications are susceptible to highly energized charged particles such as electrons and protons originating from coronal mass ejections that create geomagnetic storms. There is a need for advanced protection measures that can help minimize the impact to space electronics caused by current surges during these severe solar storms. Although optical monitoring of the sun can predict the onset of severe space weather conditions, determining the details of the conditions often requires on-board satellite sensors. Knowledge of not only the dose and dose rate, but the specific radiation type, can allow for a better assessment and mitigation of particular radiation damage effects observed for on-board electronics. Existing compact charged-particle detectors for satellites, such as the Teledyne Micro-dosimeter, provide dose and dose rate information; however, these devices do not discriminate between electron and proton events, do not provide spectroscopic information, and may have a limited radiation tolerance. The proposed solution involves expanding on Phase I results for coupling Diphenylanthracene (DPA) with a solid-state photomultiplier (SSPM) photodetector and developing the complementary readout circuitry required to detect/discriminate fast electrons from protons while providing dose and dose rate information characteristic of solar events over a wide range of energies. BENEFIT: During space flight, both the immediate dose rate and total exposure information can be recorded simultaneously by these high efficiency digital dosimeters. The compact size and inexpensive nature of these sensors also opens the possibility of monitoring many areas for comparison of radiation exposure, including individual monitors for each satellite, even for the emerging, smaller, next-generation designs. Ground-based research and comparisons will also become easier and less expensive with the SSPM dosimeter. Inexpensive radiation dosimeters are in general demand for commercial applications, such as personnel or waste monitoring; other applications include border monitoring for homeland security and protecting satellites and ground-based equipment from solar flares. The ability to inexpensively mass-produce these devices creates an entirely new market for arrays of distributed sensors.