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Neutron Environment Calculations for Low Earth Orbit
ISSN: 0148-7191, e-ISSN: 2688-3627
Published July 09, 2001 by SAE International in United States
Annotation ability available
The long term exposure of astronauts on the developing International Space Station (ISS) requires an accurate knowledge of the internal exposure environment for human risk assessment and other onboard processes. The natural environment is moderated by the solar wind, which varies over the solar cycle. The HZETRN high charge and energy transport code developed at NASA Langley Research Center can be used to evaluate the neutron environment on ISS. A time dependent model for the ambient environment in low earth orbit is used. This model includes GCR radiation moderated by the Earth’s magnetic field, trapped protons, and a recently completed model of the albedo neutron environment formed through the interaction of galactic cosmic rays with the Earth’s atmosphere. Using this code, the neutron environments for space shuttle missions were calculated and comparisons were made to measurements by the Johnson Space Center with onboard detectors. The models discussed herein are being developed to evaluate the natural and induced environment data for the Intelligence Synthesis Environment Project and eventual use in spacecraft optimization.
CitationClowdsley, M., Wilson, J., Shinn, J., Badavi, F. et al., "Neutron Environment Calculations for Low Earth Orbit," SAE Technical Paper 2001-01-2327, 2001, https://doi.org/10.4271/2001-01-2327.
- Wu, H. et al. Estimate of Space Radiation-Induced Cancer Risks for International Space Station Orbits. NASA TM-104818, 1996.
- Wilson, J.W. et al. Health Phys. 57:665–668; 1989
- Dudkin, V.E. et al. Nucl. Tracks Radiat. Meas. 20:139–141; 1992.
- Kieth, J. E. et al. Nucl. Tracks Radiat. Meas. 20:41–47; 1992.
- Badhwar, G.D. et al. Radiat. Meas. 24:283–289; 1995.
- Dudkin, V.E. et al. Radiat. Meas. 25:483–484; 1995.
- Shinn, J.L. et al. IEEE Trans. Nucl. Sci. 42:2017–2025; 1995.
- Badhwar, G.D. et al. Radiat. Meas., 24: 129–138 1995.
- Shinn, J.L. et al. IEEE Trans. Nucl. Sci. 45:2711–2719; 1998.
- Lobakov, A. P. et al. Nucl. Tracks Radiat. Meas. 20:55–58; 1992.
- Jenkins, R.W. et al. J. Geophys. Res. 76:7470–7478; 1971.
- Weigel, B. et al. Adv. Space Res. 12: 349–354; 1992.
- Wilson, J. W. et al. HZETRN:Description of a free-space ion and nucleon transport and shielding computer program. NASA TP–3495, 1995.
- Clowdsley, M.S. et al. A comparison of the multigroup and collocation methods for solving the low-energy neutron Boltzmann equation. Can. J. Phys. 78: 45–56; 2000.
- Clowdsley, M.S. et al. An Improved Elastic and Nonelastic Neutron Transport Alogrithm for Space Radiation. NASA/TP-2000-210299, 2000.
- Badhwar, G. D. and O’Neill, P. M. Nucl. Tracks Radiat. Meas. 20: 427–410; 1995.
- Wilson, J. W. et al. Solar Cycle Variation and Application to the Space Radiation Environment NASA TP-1999-209369, 1999.
- Smart, D. F.; Shea, M. A. Geomagnetic transmission functions for 400 km altitude satellite. 18th International Cosmic Ray Conference—Conference Papers MG Sessions, Vol. 3, Tata Inst. of Fundamental Research (Colaba, Bombay) pp. 419–422; 1983.
- Atwell, W. et al. Space Radiation Shielding Analysis and Dosimetry for the Space Shuttle Program. In High-Energy Radiation Background in Space, Eds. Rester A. C. & Trombka J. I., AIP Conference Preceedings 186, New York, 1989, pp. 289–296.
- Blanchard R. C.; Hess, W. N. J. Geophys. Res. 69:3927; 1964.
- Huston, S. L. et al. Adv. Space Res. 21:(12)1625–1634; 1998.
- Wilson, J.W. et al. Transport Methods and Interactions for Space Radiations, NASA RP-1257, 1991.
- Korff, S.A. et al. Atmospheric Neutrons. NASA CR 3126, 1979.