Regolith Biological Shield for a Lunar Outpost from High Energy Solar Protons

Journal Article · Mon Jan 21 00:00:00 EST 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2845005· OSTI ID:21049474

Pham, Tai T; El-Genk, Mohamed S ^[1]

---

1. Institute for Space and Nuclear Power Studies and Dept. of Chemical and Nuclear Engineering University of New Mexico, Albuquerque, NM 87131-0001 (United States)

Beyond Earth atmosphere, natural space radiation from Galactic Cosmic Rays and Solar Energetic Protons (SEPs) represents a significant hazard to both manned and robotic missions. For lunar settlements, protecting astronauts from SEPs is a key safety issue that needs to be addressed by identifying appropriate shielding materials. This paper investigates the interaction of SEPs with the lunar regolith, and quantifies the effectiveness of the regolith as a biological shield for a human habitat, compared to aluminum, presently the standard shielding material. Also calculated is the shielding thickness to reduce the dose in the habitat to those recommended by International Radiation Protection Committee and by NASA for operation on the international space station. The present calculations are for the most energetic solar event of February 1956, which included high energy protons up to 1000 MeV. Results show that the lunar regolith is as effective as aluminum for shielding lunar outposts. A large thickness of the regolith ({approx}30 g/cm{sup 2}) would be needed to reduce the dose in the habitat from high energy protons below the 30 days flight crew limit of 25 Rem (or 250 mSv) and significantly more shielding would be needed ({approx}150 g/cm{sup 2}) to reduce the dose down to the limit for radiation workers of 5 Rem (or 50 mSv)

• OSTI ID: 21049474
• Journal Information: AIP Conference Proceedings, Vol. 969, Issue 1; Conference: Space Technology and Applications International Forum-STAIF 2008: 12. conference on thermophysics applications in microgravity; 1. symposium on space resource utilization; 25. symposium on space nuclear power and propulsion; 6. conference on human/robotic technology and the vision for space exploration; 6. symposium on space colonization; 5. symposium on new frontiers and future concept, Albuquerque, NM (United States), 10-14 Feb 2008; Other Information: DOI: 10.1063/1.2845005; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS
ALUMINIUM
ASTRONAUTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL SHIELDS
COSMIC RADIATION
DOSES
EARTH ATMOSPHERE
HABITAT
HUMAN POPULATIONS
INTERNATIONAL SPACE STATION
MEV RANGE
NASA
RADIATION DOSE UNITS
RADIATION PROTECTION
SAFETY
SHIELDING
SHIELDING MATERIALS
SOLAR PROTONS
THICKNESS