Elpasolite Planetary Ice and Composition Spectrometer (EPICS): A Low-Resource Combined Gamma-Ray and Neutron Spectrometer for Planetary Science
Abstract
The Elpasolite Planetary Ice and Composition Spectrometer (EPICS) is an innovative, low-resource gamma-ray and neutron spectrometer for planetary science missions, enabled by new scintillator and photodetector technologies. Neutrons and gamma rays are produced by cosmic ray interactions with planetary bodies and their subsequent interactions with the near-surface materials produce distinctive energy spectra. Measuring these spectra reveals details of the planetary near-surface composition that are not accessible through any other phenomenology. Under the resource constraints of space missions, these measurements are difficult as they require good gamma-ray energy resolution, measurement of neutron energy over almost twelve orders of magnitude, and disentangling the effects of background cosmic radiation, all while surviving the space environment for many years. EPICS will provide a transformational advance in the investigation of these signatures, enabling new scientific discovery. EPICS will be the first planetary science instrument to fully integrate the neutron and gamma-ray spectrometers. This integration is enabled by the recently-discovered elpasolite family of scintillators that offer gamma-ray spectroscopy energy resolutions as good as 3% FWHM at 662 keV, thermal neutron sensitivity and some fast neutron spectroscopy, and the ability to distinguish gamma-ray and neutron signals via pulse shape differences. This new detection technology will significantly reduce size, weight, and power (SWaP) while providing similar neutron performance and improved gamma energy resolution compared to previous scintillator instruments, and the ability to monitor the cosmic-ray source term. EPICS will detect scintillation light with silicon photomultipliers rather than traditional photomultiplier tubes, offering dramatic additional SWaP reduction. EPICS is being developed under Los Alamos National Laboratory internal research and development funding to a maturity level appropriate for proposal to NASA planetary science missions such as a Martian moon exploration, a Trojan asteroid rendezvous, or high spatial resolution mapping of water on Mars. Here we report on the expected sensitivity and performance of EPICS in several potential missions, and on the status of the EPICS development.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.P43B2113S
- Keywords:
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- 6008 Composition;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6024 Interiors;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6040 Origin and evolution;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6055 Surfaces;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES