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Origin and Properties of Solar Energetic Particles in Space. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm125p0109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Kim MHY, Wilson JW, Cucinotta FA. Description of transport codes for space radiation shielding. HEALTH PHYSICS 2012; 103:621-639. [PMID: 23032892 DOI: 10.1097/hp.0b013e318266732f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Exposure to ionizing radiation in the space environment is one of the hazards faced by crews in space missions. As space radiations traverse spacecraft, habitat shielding, or tissues, their energies and compositions are altered by interactions with the shielding. Modifications to the radiation fields arise from atomic interactions of charged particles with orbital electrons and nuclear interactions leading to projectile and target fragmentation, including secondary particles such as neutrons, protons, mesons, and nuclear recoils. The transport of space radiation through shielding can be simulated using Monte Carlo techniques or deterministic solutions of the Boltzmann equation. To determine shielding requirements and to resolve radiation constraints for future human missions, the shielding evaluation of a spacecraft concept is required as an early step in the design process. To do this requires (1) accurate knowledge of space environmental models to define the boundary condition for transport calculations, (2) transport codes with detailed shielding and body geometry models to determine particle transmission into areas of internal shielding and at each critical body organ, and (3) the assessment of organ dosimetric quantities and biological risks by applying the corresponding response models for space radiation against the particle spectra that have been accurately determined from the transport code. This paper reviews current transport codes and analyzes their accuracy through comparison to laboratory and spaceflight data. This paper also introduces a probabilistic risk assessment approach for the evaluation of radiation shielding.
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Affiliation(s)
- Myung-Hee Y Kim
- Division of Space Life Sciences, Universities Space Research Association, Houston, TX 77058, USA.
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Lipschutz ME, Wolf SF, Vogt S, Michlovich E, Lindstrom MM, Zolensky ME, Mittlefehldt DW, Satterwhite C, Schultz L, Loeken T, Scherer P, Dodd RT, Sears DWG, Benoit PH, Wacker JF, Burns RG, Fisher DS. Consortium study of the unusual H chondrite regolith breccia, Noblesville. ACTA ACUST UNITED AC 2012. [DOI: 10.1111/j.1945-5100.1993.tb00276.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kim MHY, Hayat MJ, Feiveson AH, Cucinotta FA. Prediction of frequency and exposure level of solar particle events. HEALTH PHYSICS 2009; 97:68-81. [PMID: 19509510 DOI: 10.1097/01.hp.0000346799.65001.9c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
For future space missions outside of the Earth's magnetic field, the risk of radiation exposure from solar particle events (SPEs) during extra-vehicular activities (EVAs) or in lightly shielded vehicles is a major concern when designing radiation protection including determining sufficient shielding requirements for astronauts and hardware. While the expected frequency of SPEs is strongly influenced by solar modulation, SPE occurrences themselves are chaotic in nature. We report on a probabilistic modeling approach, where a cumulative expected occurrence curve of SPEs for a typical solar cycle was formed from a non-homogeneous Poisson process model fitted to a database of proton fluence measurements of SPEs that occurred during the past 5 solar cycles (19-23) and those of large SPEs identified from impulsive nitrate enhancements in polar ice. From the fitted model, we then estimated the expected frequency of SPEs at any given proton fluence threshold with energy >30 MeV (Phi(30)) during a defined space mission period. Analytic energy spectra of 34 large SPEs observed in the space era were fitted over broad energy ranges extending to GeV, and subsequently used to calculate the distribution of mGy equivalent (mGy-Eq) dose for a typical blood-forming organ (BFO) inside a spacecraft as a function of total Phi(30) fluence. This distribution was combined with a simulation of SPE events using the Poisson model to estimate the probability of the BFO dose exceeding the NASA 30-d limit of 250 mGy-Eq per 30 d. These results will be useful in implementing probabilistic risk assessment approaches at NASA and guidelines for protection systems for astronauts on future space exploration missions.
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Affiliation(s)
- Myung-Hee Y Kim
- Universities Space Research Association, Division of Space Life Sciences, 2101 NASA Parkway, SK/SRPE/B37, Houston, TX 77058, USA.
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Webber WR, Higbie PR, McCracken KG. Production of the cosmogenic isotopes3H,7Be,10Be, and36Cl in the Earth's atmosphere by solar and galactic cosmic rays. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007ja012499] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- W. R. Webber
- Department of Astronomy; New Mexico State University; Las Cruces New Mexico USA
| | - P. R. Higbie
- Physics Department; New Mexico State University; Las Cruces New Mexico USA
| | - K. G. McCracken
- Institute of Physical Science and Technology; University of Maryland; College Park Maryland USA
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Lario D, Simnett GM. Solar energetic particle variations. SOLAR VARIABILITY AND ITS EFFECTS ON CLIMATE 2004. [DOI: 10.1029/141gm14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Affiliation(s)
- R. Michel
- Universität Hannover, Zentrum fur Strahlenschutz und Radioökologie, Am Kleinen Felde 30, D-30167 Hannover, Germany
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Abstract
The model is intended for calculating the probability for solar energetic particles (SEP), i.e., protons and Z=2-28 ions, to have an effect on hardware and on biological and other objects in the space. The model describes the probability for the > or = 10 MeV/nucleon SEP fluences and peak fluxes to occur in the near-Earth space beyond the Earth magnetosphere under varying solar activity. The physical prerequisites of the model are as follows. 1. The occurrence of SEP is a probabilistic process. 2. The mean SEP occurrence frequency is a power-law function of solar activity (sunspot number). 3. The SEP size (taken to be the > or = 30 MeV proton fluence size) distribution is a power-law function within a 10(5)-10(11) proton/cm2 range. 4. The SEP event particle energy spectra are described by a common function whose parameters are distributed log-normally. 5. The SEP mean composition is energy-dependent and suffers fluctuations described by log-normal functions in separate events.
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Affiliation(s)
- R A Nymmik
- Institute of Nuclear Physics, Moscow State University, Russia.
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Xapsos MA, Summers GP, Shapiro P, Burke EA. New techniques for predicting solar proton fluences for radiation effects applications. IEEE TRANSACTIONS ON NUCLEAR SCIENCE 1996; 43:2772-2777. [PMID: 11540487 DOI: 10.1109/23.556865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
At geosynchronous altitudes, solar proton events can be a significant source of radiation exposure for devices such as optical imagers, memories and solar cells. These events appear to occur randomly with respect to time and magnitude during the active period of each solar cycle. New probabilistic descriptions, including extreme value theory, are given in forms applicable to assessing mission risks for both single events and the cumulative fluence of multiple events. The analyses yield simpler forms than previous models, include more recent data, and can easily be incorporated into existing computer programs.
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Affiliation(s)
- M A Xapsos
- Naval Research Laboratory, Washington, DC 20375, USA
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Garrard TL, Stone EC. Composition of energetic particles from solar flares. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 1994; 14:589-598. [PMID: 11539996 DOI: 10.1016/0273-1177(94)90514-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present a model for composition of heavy ions in the solar energetic particles (SEP). The SEP composition in a typical large solar particle event reflects the composition of the Sun, with adjustments due to fractionation effects which depend on the first ionization potential (FIP) of the ion and on the ratio of ionic charge to mass (Q/M). Flare-to-flare variations in composition are represented by parameters describing these fractionation effects and the distributions of these parameters are presented.
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Affiliation(s)
- T L Garrard
- California Institute of Technology, Pasadena 91125, USA
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Cucinotta FA, Townsend LW, Wilson JW, Golightly MJ, Weyland M. Analysis of radiation risk from alpha particle component of solar particle events. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 1994; 14:661-670. [PMID: 11538031 DOI: 10.1016/0273-1177(94)90523-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The solar particle events (SPE) will contain a primary alpha particle component, representing a possible increase in the potential risk to astronauts during an SPE over the often studied proton component. We discuss the physical interactions of alpha particles important in describing the transport of these particles through spacecraft and body shielding. Models of light ion reactions are presented and their effects on energy and linear energy transfer (LET) spectra in shielding discussed. We present predictions of particle spectra, dose, and dose equivalent in organs of interest for SPE spectra typical of those occurring in recent solar cycles. The large events of solar cycle 19 are found to have substantial increase in biological risk from alpha particles, including a large increase in secondary neutron production from alpha particle breakup.
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Affiliation(s)
- F A Cucinotta
- NASA Langley Research Center, Hampton, VA 23681, USA
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Lockwood JA, Debrunner H, Flückiger EO. Indications for diffusive coronal shock acceleration of protons in selected solar cosmic ray events. ACTA ACUST UNITED AC 1990. [DOI: 10.1029/ja095ia04p04187] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Metzger AE, Drake DM. Identification of lunar rock types and search for polar ice by gamma ray spectroscopy. ACTA ACUST UNITED AC 1990. [DOI: 10.1029/jb095ib01p00449] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Heckman GR, Wagner WJ, Hirman JW, Kunches JM. Strategies for dealing with solar particle events in missions beyond the magnetosphere. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 1989; 9:275-280. [PMID: 11537303 DOI: 10.1016/0273-1177(89)90449-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
For long duration missions beyond the magnetosphere, the hazards posed by solar particle events (SPE) require the development of new strategies to minimize both the radiation dose and the effects. Potential strategies include the development of improved short-term forecasting of SPE through better observations and research, consideration of HZE particles in real-time forecasting and monitoring, improved knowledge of the biological effects of the particles involved in SPE, and the development of methods for combining SPE forecasts with temporary shielding and chemical countermeasures. Evaluation of present capabilities and the identification of areas of further research to achieve the necessary capabilities are discussed.
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Affiliation(s)
- G R Heckman
- National Oceanic and Atmospheric Administration, Boulder, CO 80303, USA
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Debrunner H, Flückiger E, Grädel H, Lockwood JA, McGuire RE. Observations related to the acceleration, injection, and interplanetary propagation of energetic protons during the solar cosmic ray event on February 16, 1984. ACTA ACUST UNITED AC 1988. [DOI: 10.1029/ja093ia07p07206] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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