Abstract—
The article presents results of ground calibrations of the FREND neutron telescope installed onboard the TGO spacecraft of the Russian-European ExoMars project. The main goal of the FREND space experiment is to measure hydrogen content in the subsurface layer of Mars to a depth of 1 m. High resolution maps of water mass fraction in the regolith are constructed based on these measurements. During ground physical calibrations, assessments of effective areas and measurements of angular sensitivity functions were obtained for each of the five FREND detectors. We demonstrate that FREND measurement characteristics correspond to its declared scientific goals and allow detecting and investigating local areas with enhanced water/water ice concertation on the subsurface of Mars with high spatial resolution of up to 60–200 km.
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REFERENCES
Masarik, J. and Reedy, R.C., Gamma ray production and transport in Mars, J. Geophys. Res.: Planets, 1996, vol. 101, no. E8, pp. 18891–18912.
Boynton, W.V., et al., Distribution of hydrogen in the near surface of Mars: Evidence for subsurface ice deposits, Science, 2002, vol. 297, no. 5578, pp. 81–85.
Feldman, W.C., et al., Fluxes of fast and epithermal neutrons from lunar prospector: Evidence for water ice at the lunar poles, Science, 1998, vol. 281, pp. 1496–1500.
Feldman, W.C., et al., Global distribution of neutrons from Mars: Results from Mars Odyssey, Science, 2002, vol. 297, no. 5578, pp. 75–78.
Mitrofanov, I., et al., Maps of subsurface hydrogen from the High Energy Neutron Detector, Mars Odyssey, Science, 2002, vol. 297, pp. 78–81.
Mitrofanov, I.G., et al., Soil water content on Mars as estimated from neutron measurements by the HEND instrument onboard the 2001 Mars Odyssey spacecraft, Sol. Syst. Res., 2004, vol. 38, no. 4, pp. 253–257.
Lawrence, D.J., et al., Evidence for water ice near Mercury’s north pole from MESSENGER neutron spectrometer measurements, Science, 2013, vol. 339, no. 6117, pp. 292–296.
Mitrofanov, I.G., et al., Hydrogen mapping of the lunar south pole using the LRO neutron detector experiment LEND, Science, 2010, vol. 330, no. 6003, pp. 483–486.
Litvak, M.L., et al., Global maps of lunar neutron fluxes from the LEND instrument, J. Geophys. Res. E: Planets, 2012, vol. 117, no. 6003, pp. 483–486.
Maurice, S., et al., Mars Odyssey neutron data: 1. Data processing and models of water-equivalent-hydrogen distribution, J. Geophys. Res. E: Planets, 2011, vol. 116, id. E11008.
Mitrofanov, I.G., et al., Lunar exploration neutron detector for the NASA lunar reconnaissance orbiter, Space Sci. Rev., 2010, vol. 150, pp. 183–207.
Sanin, A.B., et al., Testing lunar permanently shadowed regions for water ice: LEND results from LRO, J. Geophys. Res.: Planets, 2012, vol. 117, id. E00H26.
Mitrofanov, I., et al., Fine Resolution Epithermal Neutron Detector (FREND) onboard the ExoMars Trace Gas Orbiter, Space Sci. Rev., 2018, vol. 214, art. no. 86.
Mitrofanov, I., et al., Fine Resolution Epithermal Neutron Detector (FREND) onboard ExoMars 2016 Trace Gas Orbiter. First data and future results, COSPAR, 2018, vol. 42, id. B4.1-17-18.
Mitrofanov, I.G., et al., Physical calibration of the LEND space-based neutron telescope: the sensitivity and the angular resolution, Instrum.Exp. Tech., 2016, vol. 59, no. 4, pp. 578–591.
Litvak, M.L., et al., The variations of neutron component of lunar radiation background from LEND/LRO observations, Planet. Space Sci., 2016, vol. 122, pp. 53–65.
Allison, J., et al., Recent developments in GEANT4, Nucl. Instrum. Methods Phys. Res., 2016, vol. 835, pp. 186–225.
Mesick, K.E., et al., Benchmarking Geant4 for simulating galactic cosmic ray interactions within planetary bodies, Earth Space Sci., 2018, vol. 5, pp. 324–338.
Peplowski, P.N., et al., Cosmogenic radionuclide production modeling with Geant4: Experimental benchmarking and application to nuclear spectroscopy of asteroid (16) Psyche, Nucl. Instrum. Methods Phys. Res., 2019, vol. 446, pp. 43–57.
Köhler, J., et al., Measurements of the neutron spectrum on the Martian surface with MSL/RAD, J. Geophys. Res.: Planets, 2014, vol. 119, pp. 594–603.
Malakhov, A.V., et al., Ice permafrost “oases” close to Martian equator: Planet neutron mapping based on data of FREND instrument onboard TGO orbiter of Russian-European ExoMars mission, Astron. Lett., 2020, vol. 46, pp. 407–421.
Funding
Processing of the FREND instrument calibration data is performed within the framework of the AAAA-A18-118012290370-6 grant (“Exploration”) of the Ministry of Science and Higher Education of the Russian Federation.
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Malakhov, A.V., Mitrofanov, I.G., Litvak, M.L. et al. Physical Calibrations of the FREND Instrument Installed Onboard TGO Martian Orbiter. Cosmic Res 60, 23–37 (2022). https://doi.org/10.1134/S0010952522010099
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DOI: https://doi.org/10.1134/S0010952522010099