1
|
Dynamics, Composition and Origin of the Geomagnetically-Trapped Corpuscular Radiation. ACTA ACUST UNITED AC 2021. [DOI: 10.1017/s0251107x00022331] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
2
|
|
3
|
Measurement of electrons from albedo neutron decay and neutron density in near-Earth space. Nature 2017; 552:382-385. [PMID: 29236693 DOI: 10.1038/nature24642] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 10/04/2017] [Indexed: 11/08/2022]
Abstract
The Galaxy is filled with cosmic-ray particles, mostly protons with kinetic energies greater than hundreds of megaelectronvolts. Around Earth, trapped energetic protons, electrons and other particles circulate at altitudes from about 500 to 40,000 kilometres in the Van Allen radiation belts. Soon after these radiation belts were discovered six decades ago, it was recognized that the main source of inner-belt protons (with kinetic energies of tens to hundreds of megaelectronvolts) is cosmic-ray albedo neutron decay (CRAND). In this process, cosmic rays that reach the upper atmosphere interact with neutral atoms to produce albedo neutrons, which, being prone to β-decay, are a possible source of geomagnetically trapped protons and electrons. These protons would retain most of the kinetic energy of the neutrons, while the electrons would have lower energies, mostly less than one megaelectronvolt. The viability of CRAND as an electron source has, however, been uncertain, because measurements have shown that the electron intensity in the inner Van Allen belt can vary greatly, while the neutron-decay rate should be almost constant. Here we report measurements of relativistic electrons near the inner edge of the inner radiation belt. We demonstrate that the main source of these electrons is indeed CRAND, and that this process also contributes to electrons in the inner belt elsewhere. Furthermore, measurement of the intensity of electrons generated by CRAND provides an experimental determination of the neutron density in near-Earth space-2 × 10-9 per cubic centimetre-confirming theoretical estimates.
Collapse
|
4
|
Hanu AR, Barberiz J, Bonneville D, Byun SH, Chen L, Ciambella C, Dao E, Deshpande V, Garnett R, Hunter SD, Jhirad A, Johnston EM, Kordic M, Kurnell M, Lopera L, McFadden M, Melnichuk A, Nguyen J, Otto A, Scott R, Wagner DL, Wiendels M. NEUDOSE: A CubeSat Mission for Dosimetry of Charged Particles and Neutrons in Low-Earth Orbit. Radiat Res 2016; 187:42-49. [PMID: 28001909 DOI: 10.1667/rr14491.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
During space missions, astronauts are exposed to a stream of energetic and highly ionizing radiation particles that can suppress immune system function, increase cancer risks and even induce acute radiation syndrome if the exposure is large enough. As human exploration goals shift from missions in low-Earth orbit (LEO) to long-duration interplanetary missions, radiation protection remains one of the key technological issues that must be resolved. In this work, we introduce the NEUtron DOSimetry & Exploration (NEUDOSE) CubeSat mission, which will provide new measurements of dose and space radiation quality factors to improve the accuracy of cancer risk projections for current and future space missions. The primary objective of the NEUDOSE CubeSat is to map the in situ lineal energy spectra produced by charged particles and neutrons in LEO where most of the preparatory activities for future interplanetary missions are currently taking place. To perform these measurements, the NEUDOSE CubeSat is equipped with the Charged & Neutral Particle Tissue Equivalent Proportional Counter (CNP-TEPC), an advanced radiation monitoring instrument that uses active coincidence techniques to separate the interactions of charged particles and neutrons in real time. The NEUDOSE CubeSat, currently under development at McMaster University, provides a modern approach to test the CNP-TEPC instrument directly in the unique environment of outer space while simultaneously collecting new georeferenced lineal energy spectra of the radiation environment in LEO.
Collapse
Affiliation(s)
- A R Hanu
- a NASA Goddard Space Flight Center, Greenbelt, Maryland 20771
| | - J Barberiz
- Department of bElectrical and Computer Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - D Bonneville
- c Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - S H Byun
- d Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - L Chen
- c Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - C Ciambella
- f Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - E Dao
- d Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - V Deshpande
- e Department of Mechanical Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - R Garnett
- d Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - S D Hunter
- a NASA Goddard Space Flight Center, Greenbelt, Maryland 20771
| | - A Jhirad
- Department of bElectrical and Computer Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - E M Johnston
- d Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - M Kordic
- Department of bElectrical and Computer Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - M Kurnell
- c Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - L Lopera
- f Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - M McFadden
- d Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - A Melnichuk
- Department of bElectrical and Computer Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - J Nguyen
- Department of bElectrical and Computer Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - A Otto
- e Department of Mechanical Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - R Scott
- e Department of Mechanical Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - D L Wagner
- c Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - M Wiendels
- Department of bElectrical and Computer Engineering, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| |
Collapse
|
5
|
|
6
|
|
7
|
|
8
|
|
9
|
Hess WN, Killeen J. Spatial distribution of electrons from neutron decay in the outer radiation belt. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz066i011p03671] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
10
|
Newkirk LL. Calculation of low-energy neutron flux in the atmosphere by theSnmethod. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz068i007p01825] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
11
|
Lenchek AM, Singer SF. Geomagnetically trapped protons from cosmic-ray albedo neutrons. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz067i004p01263] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
12
|
|
13
|
Dessler AJ, Karplus R. Some effects of diamagnetic ring currents on Van Allen radiation. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz066i008p02289] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
14
|
Lenchek AM, Singer SF, Wentworth RC. Geomagnetically trapped electrons from cosmic ray albedo neutrons. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz066i012p04027] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
15
|
Lenchek AM. On the anomalous component of low-energy geomagnetically trapped protons. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz067i006p02145] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
16
|
|
17
|
|
18
|
Bame SJ, Conner JP, Brumley FB, Hostetler RL, Green AC. Neutron flux and energy spectrum above the atmosphere. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz068i005p01221] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
19
|
Martin JP, Witten L, Katz L. Measurement of cosmic ray albedo neutron flux above the atmosphere. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz068i009p02613] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
20
|
|
21
|
Shedlovsky JP, Kaye JH. Radioactive nuclides produced by cosmic rays in Sputnik 4. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz068i017p05069] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
22
|
Reidy WP, Haymes RC, Korff SA. A measurement of slow cosmic-ray neutrons up to 200 kilometers. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz067i002p00459] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
23
|
Trainor JH, Lockwood JA. Neutron albedo measurements on polar orbiting satellites. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz069i015p03115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
24
|
Hess WN, Killeen J, Fan CY, Meyer P, Simpson JA. The observed outer-belt electron distribution and the neutron decay hypothesis. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz066i008p02313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
25
|
Bostrom CO, Zmuda AJ, Pieper GF. Trapped protons in the South Atlantic Magnetic Anomaly, July through December 1961: 2. Comparisons with Nerv and Relay 1 and discussion of the energy spectrum. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz070i009p02035] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
26
|
Boella G, Antoni GD, Dilworth C, Panetti M, Scarsi L, Intriligator DS. Measurement of the cosmic ray neutron flux at 4.6 billion volts geomagnetic cutoff rigidity. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz070i005p01019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
27
|
Hess WN, Killeen J. Spatial distribution of protons from neutron decay trapped by the geomagnetic field. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz071i011p02799] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
28
|
Yamashita M, Stephens LD, Patterson HW. Cosmic-ray-produced neutrons at ground level: Neutron production rate and flux distribution. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jz071i016p03817] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
29
|
|
30
|
Jenkins RW, Ifedili SO, Lockwood JA, Razdan H. The energy dependence of the cosmic-ray neutron leakage flux in the range 0.01-10 Mev. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/ja076i031p07470] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
31
|
Heidbreder E, Pinkau K, Reppin C, Schönfelder V. Measurements of the distribution in energy and angle of high-energy neutrons in the lower atmosphere. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/ja076i013p02905] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
32
|
Lockwood JA, Friling LA. Cosmic-ray neutron flux measurements above the atmosphere. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/ja073i021p06649] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
33
|
Achtermann E, Paschmann G, Hovestadt D. Flux profile of protons measured in 1967 at the equator betweenL=1.15 and 1.21. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/ja076i025p06004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
34
|
Kanbach G, Reppin C, Schönfelder V. Support for Crand Theory from measurements of Earth albedo neutrons between 70 and 250 MeV. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/ja079i034p05159] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
35
|
Farley TA, Tomassian AD, Chapman MC. Evaluation of the CRAND Source for 10- to 50-Mev trapped protons. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/ja074i019p04721] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
36
|
|
37
|
|
38
|
Wilson JW, Lambiotte JJ, Foelsche T. Structure in the fast spectra of atmospheric neutrons. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/ja074i026p06494] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
39
|
Light ES, Merker M, Verschell HJ, Mendell RB, Korff SA. Time dependent worldwide distribution of atmospheric neutrons and of their products: 2. Calculation. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/ja078i016p02741] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
40
|
Armstrong TW, Chandler KC, Barish J. Calculations of neutron flux spectra induced in the Earth's atmosphere by galactic cosmic rays. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/ja078i016p02715] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
41
|
Merker M, Light ES, Verschell HJ, Mendell RB, Korff SA. Time dependent worldwide distribution of atmospheric neutrons and of their products: 1. Fast neutron observations. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/ja078i016p02727] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
42
|
Monk SD, Joyce MJ. The design of a portable cosmic ray three-band neutron detector. RADIATION PROTECTION DOSIMETRY 2007; 123:3-14. [PMID: 16829509 DOI: 10.1093/rpd/ncl074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The design of a portable three-band cosmic-ray neutron detector is reported in this article. This instrument has been designed to characterise cosmic ray neutron fields in the upper atmosphere and in cosmic reference field facilities. The design utilises a spherical moderator with a layer of spallation material covering a central (3)He proportional counter. The instrument incorporates twelve lithium-coated diodes, six on the outside of the polyethylene layer and six placed within the structure. The dimensions, materials and arrangement of these in the instrument have been optimised with MCNPX to provide a compromise between the requirements of portability and spectral response.
Collapse
Affiliation(s)
- S D Monk
- Nuclear and Biomedical Engineering Research Group, Department of Engineering, Lancaster University, Lancaster LA1 4YR, UK
| | | |
Collapse
|
43
|
Hashemi-Nezhad S, Alamatsaz M. Detection of charged particle tracks in the volume of CN-85 detectors; attributed to neutrons. RADIAT MEAS 2006. [DOI: 10.1016/j.radmeas.2005.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
44
|
The theory of cosmic-ray and high-energy solar-particle transport in the atmosphere. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1569-4860(04)07004-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
45
|
Sheu RJ, Jiang SH. Cosmic-ray-induced neutron spectra and effective dose rates near air/ground and air/water interfaces in Taiwan. HEALTH PHYSICS 2003; 84:92-99. [PMID: 12498521 DOI: 10.1097/00004032-200301000-00008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ground-level cosmic-ray neutrons were measured at various elevations from sea level to 4,000 m in Taiwan, where the vertical cutoff of geomagnetic rigidity is high. High-efficiency Bonner cylinders were used in the measurements. The measured results were used to normalize and confirm one-dimensional transport calculations for cosmic-ray neutrons near interfaces. According to these measurements and calculations, the ground-level neutron fluence rates, effective dose rates, and their altitude dependence in Taiwan were determined. As compared with that reported elsewhere, the appreciable differences both in their absolute values and associated dependence on altitude could be attributed to the substantial latitude effect. In addition, the energy spectra of cosmic-ray neutrons near air/ground and air/water interfaces were measured. The neutron fluence rate near the air/ground interface is greater than that near the air/water interface; however, the spectral shape is harder at the air/water interface than at the air/ground interface. The air/ground and in-flight spectra differ somewhat at low energies, especially in the thermal energy region, but the general shapes of the spectra are similar to each other. The influence of the difference in spectral shape on the evaluation of effective dose rate was investigated.
Collapse
Affiliation(s)
- R J Sheu
- Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 300, Taiwan, ROC
| | | |
Collapse
|
46
|
Wilson JW, Goldhagen P, Rafnsson V, Clem JM, De Angelis G, Friedberg W. Overview of atmospheric ionizing radiation (AIR) research: SST-present. ADVANCES IN SPACE RESEARCH : THE OFFICIAL JOURNAL OF THE COMMITTEE ON SPACE RESEARCH (COSPAR) 2003; 32:3-16. [PMID: 14727657 DOI: 10.1016/s0273-1177(03)90364-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Supersonic Transport (SST) program, proposed in 1961, first raised concern for the exposure of pregnant occupants by solar energetic particles (SEP), and neutrons were suspected to have a main role in particle propagation deep into the atmosphere. An eight-year flight program confirmed the role of SEP as a significant hazard and of the neutrons as contributing over half of the galactic cosmic ray exposures, with the largest contribution from neutrons above 10 MeV. The FAA Advisory Committee on the Radiobiological Aspects of the SST provided operational requirements. The more recent lowering of ICRP-recommended exposure limits (1990) with the classification of aircrew as "radiation workers" renewed interest in GCR background exposures at commercial flight altitudes and stimulated epidemiological studies in Europe, Japan, Canada and the USA. The proposed development of a High Speed Civil Transport (HSCT) required validation of the role of high-energy neutrons, and this resulted in ER-2 flights at solar minimum (June 1997) and studies on effects of aircraft materials on interior exposures. Recent evaluation of health outcomes of DOE nuclear workers resulted in legislation for health compensation in year 2000 and recent European aircrew epidemiological studies of health outcomes bring renewed interest in aircraft radiation exposures. As improved radiation models become available, it is imperative that a corresponding epidemiological program of US aircrew be implemented.
Collapse
Affiliation(s)
- J W Wilson
- NASA Langley Research Center, Hampton, VA 23681, USA.
| | | | | | | | | | | |
Collapse
|
47
|
Abstract
Human exposures to ionizing radiation have been vastly altered by developing technology in the last century. This has been most obvious in the development of radiation generating devices and the utilization of nuclear energy. But even air travel has had its impact on human exposure. Human exposure increases with advancing aircraft technology as a result of the higher operating altitudes reducing the protective cover provided by Earth's atmosphere from extraterrestrial radiations. This increase in operating altitudes is taken to a limit by human operations in space. Less obvious is the changing character of the radiations at higher altitudes. The associated health risks are less understood with increasing altitude due to the increasing complexity and new field components found in high-altitude and space operations.
Collapse
Affiliation(s)
- J W Wilson
- Materials Division, NASA Langley Research Center, Hampton, VA 23681-0001, USA.
| |
Collapse
|
48
|
Tume P, Lewis BJ, Bennett LG, Pierre M, Cousins T, Hoffarth BE, Jones TA, Brisson JR. Assessment of the cosmic radiation exposure on Canadian-based routes. HEALTH PHYSICS 2000; 79:568-575. [PMID: 11045532 DOI: 10.1097/00004032-200011000-00015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
As a result of the recent recommendations of the ICRP-60 and in anticipation of possible regulation on occupational exposure of commercial aircrew, a two-phase investigation was carried out over a 1-y period to determine the total dose equivalent on representative Canadian-based flight routes. In the first phase of the study, dedicated scientific flights on a Northern round-trip route between Ottawa and Resolute Bay provided the opportunity to characterize the complex mixed-radiation field and to intercompare various instrumentation using both a conventional suite of powered detectors and passive dosimetry. In the second phase, volunteer aircrew carried (passive) neutron bubble detectors during their routine flight duties. From these measurements, the total dose equivalent was derived for a given route with a knowledge of the neutron fraction as determined from the scientific flights and computer code (CARI-3C) calculations. This study has yielded an extensive database of over 3,100 measurements providing the total dose equivalent for 385 different routes. By folding in flight frequency information and the accumulated flight hours, the annual occupational exposures of 20 flight crew have been determined. This study has indicated that most Canadian-based domestic and international aircrew will exceed the proposed annual ICRP-60 public limit of 1 mSv y(-1) but will be well below the occupational limit of 20 mSv y(-1).
Collapse
Affiliation(s)
- P Tume
- Royal Military College of Canada, Kingston, Ontario.
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
The intensity of the different particles making up atmospheric cosmic radiation, their energy distribution, and their potential biological effect on aircraft occupants vary with altitude, geomagnetic latitude, and time in the sun's magnetic activity cycle. Dose rates from cosmic radiation at commercial aviation altitudes are such that crews working on present-day jet aircraft are an occupationally exposed group with a relatively high average effective dose. Crews of future high speed commercial aircraft flying at higher altitudes would be even more exposed. Present calculations of such exposures are uncertain because knowledge of important components of the radiation field comes primarily from theoretical predictions. To help reduce these uncertainties for high-altitude flight, the National Aeronautics and Space Administration (NASA) and the Department of Energy (DOE) started the Atmospheric Ionizing Radiation (AIR) project. The measurement part of the AIR project is an international collaboration of 12 laboratories placing 14 instruments on multiple flights of a NASA ER-2 aircraft. This paper describes the basic features of cosmic radiation in the atmosphere as they relate to exposure of aircraft occupants and then describes the AIR ER-2 measurements and presents some preliminary results from a series of flights in June 1997.
Collapse
Affiliation(s)
- P Goldhagen
- US Department of Energy, Environmental Measurements Laboratory, New York, NY 10014-4811, USA.
| |
Collapse
|
50
|
Masarik J, Beer J. Simulation of particle fluxes and cosmogenic nuclide production in the Earth's atmosphere. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jd200091] [Citation(s) in RCA: 473] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|