Galactic cosmic ray-induced radiation dose on terrestrial exoplanets.

Science.gov (United States)

Atri, Dimitra; Hariharan, B; Grießmeier, Jean-Mathias

2013-10-01

This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground- and space-based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets that reside in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Planetary systems around M dwarfs are considered to be prime candidates to search for life beyond the Solar System. Such planets are likely to be tidally locked and have close-in habitable zones. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in the case of super-Earths. Such exoplanets are subjected to a high flux of galactic cosmic rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin that strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the radiation dose. Along with the magnetic field, another factor governing the radiation dose is the depth of the planetary atmosphere. The higher the depth of the planetary atmosphere, the lower the flux of secondary particles will be on the surface. If the secondary particles are energetic enough, and their flux is sufficiently high, the radiation from muons can also impact the subsurface regions, such as in the case of Mars. If the radiation dose is too high, the chances of sustaining a long-term biosphere on the planet are very low. We have examined the dependence of the GCR-induced radiation dose on the strength of the planetary magnetic field and its atmospheric depth, and found that the latter is the decisive factor for the protection of a planetary biosphere.

Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25

Science.gov (United States)

Miyake, Shoko; Kataoka, Ryuho; Sato, Tatsuhiko

2017-04-01

Weak solar activity and high cosmic ray flux during the coming solar cycle are qualitatively anticipated by the recent observations that show the decline in the solar activity levels. We predict the cosmic ray modulation and resultant radiation exposure at flight altitude by using the time-dependent and three-dimensional model of the cosmic ray modulation. Our galactic cosmic ray (GCR) model is based on the variations of the solar wind speed, the strength of the heliospheric magnetic field, and the tilt angle of the heliospheric current sheet. We reproduce the 22 year variation of the cosmic ray modulation from 1980 to 2015 taking into account the gradient-curvature drift motion of GCRs. The energy spectra of GCR protons obtained by our model show good agreement with the observations by the Balloon-borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) and the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) except for a discrepancy at the solar maximum. Five-year annual radiation dose around the solar minimum at the solar cycle 24/25 will be approximately 19% higher than that in the last cycle. This is caused by the charge sign dependence of the cosmic ray modulation, such as the flattop profiles in a positive polarity.

Cosmic radiation

Energy Technology Data Exchange (ETDEWEB)

Capdevielle, J N

1984-01-01

First, the different instruments and techniques of cosmic particle detection are presented. Then the passage of the cosmic particles through the atmosphere is studied: electrons, photons, muons. The collective behavior of the different categories is also studied, the electromagnetic cascade is distinguished from the hadron cascade. Through the principal physical properties of the radiation and the medium, the ''mean'' aspects of the radiation are then successively dealt with out of the atmosphere, at different altitudes until the sea level, then at great depths. A chapter is devoted to cosmic radiation of more than 10,000 GeV, studied separately. Then solar radiation in universe is studied through their propagation in solar system and their origin. At last, the cosmic radiation effects are studied in environment (cosmic biophysics) and some applications of cosmic radiation are presented.

Hazards of cosmic radiation

International Nuclear Information System (INIS)

Bonnet-Bidaud, J.M.; Dzitko, H.

2000-06-01

The main limitations on long-distance space transport is neither the energy source nor the propulsion system but appears to be the protection of cosmonauts from radiation. Cosmic radiation is made up of protons (87%), alpha particles (12%) and heavy nuclei (1%), all these particles travel through interstellar space and come from the explosion of stars at the end of their life. The earth is protected from cosmic radiation by 3 natural shields: i) the magnetic field generated by the solar wind, ii) the earth magnetic field (magnetosphere), and iii) the earth atmosphere, this elusive layer of air is equivalent to a 10 meter-high volume of water. Magnetosphere and atmosphere reduce the radiation dose by a factor 4000. According to a European directive (1996) air crews must be considered as radiation workers. (A.C.)

Cosmic radiation algorithm utilizing flight time tables

International Nuclear Information System (INIS)

Katja Kojo, M.Sc.; Mika Helminen, M.Sc.; Anssi Auvinen, M.D.Ph.D.; Katja Kojo, M.Sc.; Anssi Auvinen, M.D.Ph.D.; Gerhard Leuthold, D.Sc.

2006-01-01

Cosmic radiation is considerably higher on cruising altitudes used in aviation than at ground level. Exposure to cosmic radiation may increase cancer risk among pilots and cabin crew. The International Commission on Radiation Protection (ICRP) has recommended that air crew should be classified as radiation workers. Quantification of cosmic radiation doses is necessary for assessment of potential health effects of such occupational exposure. For Finnair cabin crew (cabin attendants and stewards), flight history is not available for years prior to 1991 and therefore, other sources of information on number and type of flights have to be used. The lack of systematically recorded information is a problem for dose estimation for many other flight companies personnel as well. Several cosmic radiation dose estimations for cabin crew have been performed using different methods (e.g. 2-5), but they have suffered from various shortcomings. Retrospective exposure estimation is not possible with personal portable dosimeters. Methods that employ survey data for occupational dose assessment are prone to non-differential measurement error i.e. the cabin attendants do not remember correctly the number of past flights. Assessment procedures that utilize surrogate measurement methods i.e. the duration of employment, lack precision. The aim of the present study was to develop an assessment method for individual occupational exposure to cosmic radiation based on flight time tables. Our method provides an assessment method that does not require survey data or systematic recording of flight history, and it is rather quick, inexpensive, and possible to carry out in all other flight companies whose past time tables for the past periods exist. Dose assessment methods that employ survey data are prone to random error i.e. the cabin attendants do not remember correctly the number or types of routes that they have flown during the past. Our method avoids this since survey data are not needed

A NIRS's product. Japanese internet system for the calculation of aviation route doses 'JISCARD'. The program which informs us of cosmic radiation doses in an aircraft

International Nuclear Information System (INIS)

Yasuda, Hiroshi

2008-01-01

The radiation dose during one round aviation from Japan to Western countries is about 0.1 mSv. A web tool called JISCARD (Japanese Internet System for the Calculation of Aviation Route Doses) has been developed by National Institute of Radiological Sciences for giving the information on the irradiation of cosmic ray during the aviation. 'Route dose' (the effective dose by cosmic ray irradiation) of going and coming each can be shown for major international airlines from/to Japan. 'JISCARD Mobile' for mobile phones is also available. Global distribution of daily cosmic ray intensity at cruising altitude (11 km) of aircrafts is shown on the page 'Related Information'. Explanation of the terminology is also compiled. (K.Y.)

Management of cosmic radiation exposure for aircraft crew in Japan

International Nuclear Information System (INIS)

Yasuda, H.; Sato, T.; Yonehara, H.; Kosako, T.; Fujitaka, K.; Sasaki, Y.

2011-01-01

The International Commission on Radiological Protection has recommended that cosmic radiation exposure of crew in commercial jet aircraft be considered as occupational exposure. In Japan, the Radiation Council of the government has established a guideline that requests domestic airlines to voluntarily keep the effective dose of cosmic radiation for aircraft crew below 5 mSv y -1 . The guideline also gives some advice and policies regarding the method of cosmic radiation dosimetry, the necessity of explanation and education about this issue, a way to view and record dose data, and the necessity of medical examination for crew. The National Inst. of Radiological Sciences helps the airlines to follow the guideline, particularly for the determination of aviation route doses by numerical simulation. The calculation is performed using an original, easy-to-use program package called 'JISCARD EX' coupled with a PHITS-based analytical model and a GEANT4-based particle tracing code. The new radiation weighting factors recommended in 2007 are employed for effective dose determination. The annual individual doses of aircraft crew were estimated using this program. (authors)

Measurements of the dose due to cosmic rays in aircraft

International Nuclear Information System (INIS)

Vukovic, B.; Lisjak, I.; Radolic, V.; Vekic, B.; Planinic, J.

2006-01-01

When the primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The cosmic radiation dose aboard A320 and ATR 42 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; radon concentration in the atmosphere was measured with the Alpha Guard radon detector. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed by the flights Zagreb-Paris-Buenos Aires and reversely, when one measured cosmic radiation dose; for 26.7 h of flight, the TLD dosimeter registered the total dose of 75 μSv and the average dose rate was 2.7 μSv/h. In the same month, February 2005, a traveling to Japan (24 h flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 μSv/h

Measurements of the dose due to cosmic rays in aircraft

Energy Technology Data Exchange (ETDEWEB)

Vukovic, B. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Lisjak, I. [Croatia Airlines, Zagreb (Croatia); Radolic, V. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Vekic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Planinic, J. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia)]. E-mail: planinic@ffos.hr

2006-06-15

When the primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The cosmic radiation dose aboard A320 and ATR 42 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; radon concentration in the atmosphere was measured with the Alpha Guard radon detector. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed by the flights Zagreb-Paris-Buenos Aires and reversely, when one measured cosmic radiation dose; for 26.7 h of flight, the TLD dosimeter registered the total dose of 75 {mu}Sv and the average dose rate was 2.7 {mu}Sv/h. In the same month, February 2005, a traveling to Japan (24 h flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 {mu}Sv/h.

Cosmic-ray-induced radiation environment and dose to man for low-orbit space applications

International Nuclear Information System (INIS)

Sandmeier, H.A.; Hansen, G.E.; Battat, M.E.; O'Brien, K.

1981-09-01

Neutrons and photons resulting from the interaction of galactic cosmic rays with the material of an orbiting satellite or an orbiting space station at an altitude of some few hundreds of kilometers, and below the level of the radiation belts, have been calculated as a function of geomagnetic latitude and solar activity level. The photon and neutron leakage currents from the top of the atmosphere have been computed. The radiation dose-equivalent rate to an unshielded astronaut has also been calculated. The maximum dose-equivalent rate, near the magnetic poles, was 2 mrem/h. In deep space this would amount to 18 rem/y, indicating that for a prolonged stay in space, shielding would be needed

Contribution of cosmic rays to radiation exposure of the population

International Nuclear Information System (INIS)

Sztanyik, L.B.; Nikl, I.

1982-01-01

To evaluate the exposure of the Hungarian population to cosmic rays, the absorbed dose rate in air of cosmic radiation was directly measured by high pressure ionization chamber at ground level on the surface of different bodies of water and at various altitudes on the board of an aircraft. From the dose rates measured this way, the outdoor dose equivalent rate from the ionizing components of cosmic radiation to people living at sea level would be 300-325 μSv per year. Taking into account the altitude distribution of the population, the average weighted dose equivalent is about 320 μSv per year. At Kekestetoe, the highest peak of the Matra Mountains, (the highest altitude in Hungary), the annual dose equivalent is about 50 per cent higher than on the Great Hungarian Plain. (author)

Radiation Exposure of Passengers to Cosmic Radiation

International Nuclear Information System (INIS)

Salah El-Din, T.; Gomaa, M.A.; Sallah, N.

2010-01-01

The main aim of the present study is to review exposure of Egyptian passengers and occupational workers to cosmic radiation during their work. Computed effective dose of passengers by computer code CARI-6 using during either short route, medium route or long route as well as recommended allowed number of flights per year

Cosmic rays exposure during aircraft flight (3). Guideline and dose evaluation

International Nuclear Information System (INIS)

Yasuda, Hiroshi

2007-01-01

Radiation Council of MEXT drew up the Guideline of Cosmic Ray Exposure Control for Air Crew in 2006. The content of the Guideline and evaluation methods of dose are explained. The Guideline stated five items for Airline Company. It consists of 1) exposure dose control for air crew, 2) evaluation methods of cosmic rays exposure dose of air crew, 3) explanation and education of cosmic rays exposure for air crew, 4) reading, record and store of cosmic rays exposure dose of air crew, and 5) health control of air crew. The doses of four airlines were calculated by the Civil Aeromedical Research Institute (CARI) code and the European Program package for the Calculation of Aviation Route Doses (EPCARD) code. The difference of two codes was about 15 to 25%. Japanese Internet System for Calculation of Aviation Route Doses (JISCAED) has been developed by Japan. (S.Y.)

Measurements of the Cosmic Radiation Doses at Board of Aircraft of Polish Airlines LOT. Part 1

International Nuclear Information System (INIS)

Bilski, P.; Budzanowski, M.; Horwacik, T.; Marczewska, B.; Olko, P.

2000-12-01

Radiation doses received by a group of 30 pilots of the Polish Airlines LOT were investigated between July and October 2000. The measurement of the low-LET component of the cosmic radiation, lasting in average 2 months, was performed with 7 LiF:Mg,Ti and 7 L iF:Mg,Cu,P thermoluminescent detectors. The neutron component was measured with the thermoluminescent albedo cassettes. Additionally for all flights, records of altitude profiles were kept and effective doses were then calculated with the CARI-6 computer code. In total, about 560 flights were included in the calculations. The highest obtained dose was about 0.8 mSv in 2 months. Results of calculations are mostly consistent with the results of measurements. (author)

Hazards of cosmic radiation; Radiation cosmique: danger dans l'espace

Energy Technology Data Exchange (ETDEWEB)

Bonnet-Bidaud, J M; Dzitko, H

2000-06-01

The main limitations on long-distance space transport is neither the energy source nor the propulsion system but appears to be the protection of cosmonauts from radiation. Cosmic radiation is made up of protons (87%), alpha particles (12%) and heavy nuclei (1%), all these particles travel through interstellar space and come from the explosion of stars at the end of their life. The earth is protected from cosmic radiation by 3 natural shields: (i) the magnetic field generated by the solar wind, (ii) the earth magnetic field (magnetosphere), and (iii) the earth atmosphere, this elusive layer of air is equivalent to a 10 meter-high volume of water. Magnetosphere and atmosphere reduce the radiation dose by a factor 4000. According to a European directive (1996) air crews must be considered as radiation workers. (A.C.)

Influence of clouds on the cosmic radiation dose rate on aircraft

International Nuclear Information System (INIS)

Pazianotto, Mauricio T.; Carlson, Brett V.; Federico, Claudio A.; Goncalez, Odair L.; Cortes-Giraldo, Miguel A.; Quesada, Jose Manuel M.; Palomo, Francisco R.; Pinto, Marcos Luiz de A.

2014-01-01

Flight missions were made in Brazilian territory in 2009 and 2011 with the aim of measuring the cosmic radiation dose rate incident on aircraft in the South Atlantic Magnetic Anomaly and to compare it with Monte Carlo simulations. During one of these flights, small fluctuations were observed in the vicinity of the aircraft with formation of Cumulonimbus clouds. Motivated by these observations, in this work, the authors investigated the relationship between the presence of clouds and the neutron flux and dose rate incident on aircraft using computational simulation. The Monte Carlo simulations were made using the MCNPX and Geant4 codes, considering the incident proton flux at the top of the atmosphere and its propagation and neutron production through several vertically arranged slabs, which were modelled according to the ISO specifications. The paper presents first-order calculation about the influence of Cumulonimbus clouds on the flux and dose rate due to cosmic neutrons in the atmosphere, at aircraft flight altitudes. The simulations show variations of the order of 5.5 % in the neutrons flux and 3.6 % of the dose rate due to the presence of the cloud. Such variations can extend up to ∼1.5 km from the edge of the cloud. The spectrum of neutrons within a cloud formation was observed undergo changes due to the neutron absorption and scattering processes with the water content inside the cloud. To accomplish these simulations, it is important to have a proper knowledge of the data libraries and nuclear models to be applied, since the simulation processes are strongly dependent on these factors. These results emphasise the importance of conducting more detailed studies on this topic, since the influence of clouds can change the dose and flux on aircraft overflying such formations, as well as could explain some of the fluctuations in the experimental dose rate data obtained in aircraft flights. Future studies should extend such simulations to different types of

CONCORD: comparison of cosmic radiation detectors in the radiation field at aviation altitudes

Czech Academy of Sciences Publication Activity Database

Meier, M.; Trompier, F.; Ambrožová, Iva; Kubančák, Ján; Matthia, D.; Ploc, Ondřej; Santen, N.; Wirtz, M.

2016-01-01

Roč. 6, MAY (2016), A24 ISSN 2115-7251 Institutional support: RVO:61389005 Keywords : aviation * radiation exposure of aircrew * comparison of radiation detectors * galactic cosmic radiation * ambient dose equivalent Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.446, year: 2016

Exposure to cosmic radiation: a developing major problem in radiation protection

International Nuclear Information System (INIS)

Lowder, W.M.; Hajnal, F.

1992-01-01

'Full Text:' Cosmic radiation at ground altitudes is usually a relatively minor contributor to human radiation exposure, producing a global collective dose equivalent that is about 10 percent of the total from all natural sources. However, more than a million people living at high altitudes receive annual dose equivalents in excess of 5 mSv. In recent years, there has been increasing concern about the exposure of aircraft flight crews and passengers, for whom annual dose equivalents of up to several mSv have been estimated. Recent EML results indicate the presence of an important high-energy neutron component at jet aircraft altitudes, perhaps producing dose equivalents of the order of 0.1. mSv/h at high latitudes. Finally, space agencies have been long concerned with the potential exposures of astronauts, especially from the rare massive solar flare events. As more people venture into space, this source of human radiation exposure will become increasingly important. Available date on those aspects of cosmic radiation exposure will be reviewed, along with current and anticipated future research activities that may yield and improve assessment of the problem. The question of how such exposures might be controlled will be addressed, but not answered. (author)

An estimate of cosmic dose component around Kudankulam site

International Nuclear Information System (INIS)

Vijayakumar, B.; Thomas, G.; Rajan, P.S.; Selvi, B.S.; Balamurugan, M.; Ravi, P.M.; Tripathi, R.M.

2015-01-01

Natural ionizing radiation pervades the whole environment and enters human lives in a wide variety of ways. It arises from natural processes such as the decay of terrestrially deposited radionuclides in the earth, and artificial processes like the use of X-rays in medicine. Thus, radiation can be classified as natural and artificial depending on its origin. Natural sources include cosmic rays, terrestrial gamma radiation, radon and its decay products in air and various radio nuclides found naturally in food and drink. Cosmic rays reach the earth from outer space. Artificial sources include medical X-rays, therapeutic use of radioisotopes, fallout from past weapon tests, discharges from nuclear industry, industrial gamma rays and use of radioisotopes in consumer products. This paper attempts to estimate the natural cosmic dose component around Kudankulam Nuclear Power Plant site in the south eastern coast of India. (author)

Hazards of cosmic radiation; Radiation cosmique: danger dans l'espace

Energy Technology Data Exchange (ETDEWEB)

Bonnet-Bidaud, J.M.; Dzitko, H

2000-06-01

The main limitations on long-distance space transport is neither the energy source nor the propulsion system but appears to be the protection of cosmonauts from radiation. Cosmic radiation is made up of protons (87%), alpha particles (12%) and heavy nuclei (1%), all these particles travel through interstellar space and come from the explosion of stars at the end of their life. The earth is protected from cosmic radiation by 3 natural shields: (i) the magnetic field generated by the solar wind, (ii) the earth magnetic field (magnetosphere), and (iii) the earth atmosphere, this elusive layer of air is equivalent to a 10 meter-high volume of water. Magnetosphere and atmosphere reduce the radiation dose by a factor 4000. According to a European directive (1996) air crews must be considered as radiation workers. (A.C.)

Inconstant sun: how solar evolution has affected cosmic and ultraviolet radiation exposure over the history of life on Earth.

Science.gov (United States)

Karam, P Andrew

2003-03-01

Four billion years ago, sea-level UV exposure was more than 400 times as intense as today, the dose from solar cosmic rays was five times present levels, and galactic cosmic rays accounted for only about 10% their current contribution to sea-level radiation doses. Exposure to cosmic radiation accounts for about 10% of natural background radiation exposure today and includes dose from galactic cosmic rays and solar charged particles. There is little exposure to ionizing wavelengths of UV due to absorption by ozone. The sun has evolved significantly over its life; in the past there were higher levels of particulate radiation and lower UV emissions from the sun, and a stronger solar wind reduced radiation dose in the inner solar system from galactic cosmic rays. Finally, since the early atmosphere contained little to no oxygen, surface levels of UV radiation were far higher in the past.

Cosmic radiation exposure in supersonic and subsonic flight

International Nuclear Information System (INIS)

Anon.

1975-01-01

The main body of this document consists of four major sections: (1) an introduction describing the scope of Committee operations and proving a brief exposition of the concepts of radiation protection; (2) a survey of experimental and theoretical data on cosmic radiations that have been obtained in individual research projects with emphasis on investigations that were performed under the sponsorship of the Committee. The studies evaluate galactic and solar radiation as a function of altitude and magnetic latitude; (3) best current estimates of cosmic radiation levels in the atmosphere; and (4) radiation protection recommendations dealing with maximum permissible doses and operational aspects covering satellite warning systems, on-board instrumentation, and forecasting. Nine annexes submitted by individual authors cover various of these subjects in greater detail

Measurement of secondary cosmic radiation and calculation of associated dose conversion coefficients for humans

International Nuclear Information System (INIS)

Simmer, Gregor

2012-01-01

Due to secondary cosmic radiation (SCR), pilots and flight attendants receive elevated effective doses at flight altitudes. For this reason, since 2003 aircrew members are considered as occupationally exposed, in Germany. This work deals with the calculation of dose conversion coefficients (DCC) for protons, neutrons, electrons, positrons, photons and myons, which are crucial for estimation of effective dose from SCR. For the first time, calculations were performed combining Geant4 - a Monte Carlo code developed at CERN - with the voxel phantoms for the reference female and male published in 2008 by ICRP and ICRU. Furthermore, measurements of neutron fluence spectra - which contribute the major part to the effective dose of SCR - were carried out at the Environmental Research Station Schneefernerhaus (UFS) located at 2650 m above sea level nearby the Zugspitze mountain, Germany. These measured neutron spectra, and additionally available calculated spectra, were then folded with the DCC calculated in this work, and effective dose rates for different heights were calculated.

Study of the contribution of the different components of atmospheric cosmic radiation in dose received by the aircraft crew

International Nuclear Information System (INIS)

Pereira, Marlon A.; Prado, Adriane C.M.; Federico, Claudio A.; Goncalez, Odair L.

2014-01-01

The crews and aircraft passengers are exposed to atmospheric cosmic radiation. The flow of this radiation is modulated by the solar cycle and space weather, varying with the geomagnetic latitude and altitude. This paper presents a study of the contributions of radiation in total ambient dose equivalent of the crews depending on flight altitude up to 20 km, during maximum and minimum solar and in equatorial and polar regions. The results of calculations of the particle flows generated by the EXPACS and QARM codes are used. The particles evaluated that contributing significantly in the ambient dose equivalent are neutrons, protons, electrons, positrons, alphas, photons, muons and charged pions. This review allows us to characterize the origin of the dose received by crews and also support a project of a dosimetric system suitable for this ionizing radiation field in aircraft and on the ground

Annual radiation dose in thermoluminescence dating

International Nuclear Information System (INIS)

Li Huhou

1988-01-01

The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned

Annual radiation dose in thermoluminescence dating

Energy Technology Data Exchange (ETDEWEB)

Huhou, Li [Chinese Academy of Social Sciences, Beijing, BJ (China). Inst. of Archaeology

1988-11-01

The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned.

The effects of cosmic radiation on implantable medical devices

International Nuclear Information System (INIS)

Bradley, P.

1996-01-01

Metal oxide semiconductor (MOS) integrated circuits, with the benefits of low power consumption, represent the state of the art technology for implantable medical devices. Three significant sources of radiation are classified as having the ability to damage or alter the behavior of implantable electronics; Secondary neutron cosmic radiation, alpha particle radiation from the device packaging and therapeutic doses(up to 70 Gγ) of high energy radiation used in radiation oncology. The effects of alpha particle radiation from the packaging may be eliminated by the use of polyimide or silicone rubber die coatings. The relatively low incidence of therapeutic radiation incident on an implantable device and the use of die coating leaves cosmic radiation induced secondary neutron single event upset (SEU) as the main pervasive ionising radiation threat to the reliability of implantable devices. A theoretical model which predicts the susceptibility of a RAM cell to secondary neutron cosmic radiation induced SEU is presented. The model correlates well within the statistical uncertainty associated with both the theoretical and field estimate. The predicted Soft Error Rate (SER) is 4.8 x l0 -12 upsets/(bit hr) compared to an observed upset rate of 8.5 x 10 -12 upsets/(bit hr) from 20 upsets collected over a total of 284672 device days. The predicted upset rate may increase by up to 20% when consideration is given to patients flying in aircraft The upset rate is also consistent with the expected geographical variations of the secondary cosmic ray neutron flux, although insufficient upsets precluded a statistically significant test. This is the first clinical data set obtained indicating the effects of cosmic radiation on implantable devices. Importantly, it may be used to predict the susceptibility of future to the implantable device designs to the effects of cosmic radiation

Dosimetry of environmental radiations (cosmic ray)

International Nuclear Information System (INIS)

Yamasaki, Keizo

1978-01-01

Cosmic ray is dominant as environmental radiation, though the experimental determination made on cosmic ray doses is few in Japan. The free air ionization intensity at sea level due to cosmic ray has been estimated in the Bay of Wakasa, Japan, at middle geomagnetic latitude (25 deg. N), in October 1977. The ionization chambers used were two air and one argon types. Where the responses to cosmic and terrestrial gamma rays were equal, the ionization intensity due to cosmic ray was obtained by subtracting the ionization intensity due to terrestrial gamma ray from the total ionization intensity. As the terrestrial gamma ray, (1) U-238 series, Th-232 series, and K-40 in seawater, (2) K-40 in the material of a wooden ship, and (3) Rn-222 and its daughter products in the atmosphere were considered. The result of free air ionization due to cosmic ray with the argon chamber was slightly smaller than those with the other two air chambers; however, both were in good agreement within standard errors. (JPN.)

Mapping the exposure of the Brazilian population to natural background radiation - cosmic radiation

Energy Technology Data Exchange (ETDEWEB)

Rochedo, Elaine R.R., E-mail: elaine@ird.gov.br [Instituto de Radioprotecao e Dosimetria (lRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Salles, Krause C.S.; Prado, Nadya M.C., E-mail: krausesalles@yahoo.com.br, E-mail: nadya@ime.ib.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

2013-07-01

The main objective of this work is to statically and graphically describe the exposure of the Brazilian population to natural background radiation. in this stage, doses due to cosmic rays is being assessed based on sea level dose rates, corrected by latitude and altitude, according to the model recommended by UNSCEAR. In this work, the doses were estimated for ali Brazilian municipalities with more than 100.000 inhabitants. The 253 municipalities selected for this study include about 52% of the Brazilian population. Average dose rate was estimated to be about 50 n Sv/h with a variation coefficient of 31%. The estimated doses have shown a strong influence of altitude on dose rates, with a correlation coefficient of 0,998 for ao exponential fit. This result confirms previous studies that show a large effect of the altitude 00 exposure from cosmic radiation. Considering the same occupation and shielding conditions used by UNSCEAR as global averages, average annual dose was estimated to be 0,37 (0,24 - 0,76) mSv/y, very close to UNSCEAR worldwide average of 0,38 (0,3 - 1,0) mSv/y. (author)

Mapping the exposure of the Brazilian population to natural background radiation - cosmic radiation

International Nuclear Information System (INIS)

Rochedo, Elaine R.R.; Salles, Krause C.S.; Prado, Nadya M.C.

2013-01-01

The main objective of this work is to statically and graphically describe the exposure of the Brazilian population to natural background radiation. in this stage, doses due to cosmic rays is being assessed based on sea level dose rates, corrected by latitude and altitude, according to the model recommended by UNSCEAR. In this work, the doses were estimated for ali Brazilian municipalities with more than 100.000 inhabitants. The 253 municipalities selected for this study include about 52% of the Brazilian population. Average dose rate was estimated to be about 50 n Sv/h with a variation coefficient of 31%. The estimated doses have shown a strong influence of altitude on dose rates, with a correlation coefficient of 0,998 for ao exponential fit. This result confirms previous studies that show a large effect of the altitude 00 exposure from cosmic radiation. Considering the same occupation and shielding conditions used by UNSCEAR as global averages, average annual dose was estimated to be 0,37 (0,24 - 0,76) mSv/y, very close to UNSCEAR worldwide average of 0,38 (0,3 - 1,0) mSv/y. (author)

Characteristics of natural background external radiation and effective dose equivalent

International Nuclear Information System (INIS)

Fujimoto, Kenzo

1989-01-01

The two sources of natural radiation - cosmic rays and primordial radionuclides - are described. The factors affecting radiation doses received from natural radiation and the calculation of effective dose equivalent due to natural radiation are discussed. 10 figs., 3 tabs

Cosmic-ray contribution in measurement of environmental gamma-ray dose

International Nuclear Information System (INIS)

Nagaoka, Kazunori; Honda, Kouichirou; Miyano, Keiji

1996-01-01

Nowadays several kinds of dosimeters are being used for environmental gamma-ray monitoring. However the results measured by those instruments are not always in good agreement. It may be caused from the different characteristics of dosimeters. In particular the different responses of the instruments to cosmic-rays give significant influence on the results. Environmental radiation measurements at various altitudes on Mt. Fuji were carried out using a scintillation spectrometer with 3''φ spherical NaI(Tl), a pressurized ionization chamber (PIC), an air-equivalent ionization chamber (IC), thermoluminescence dosimeters (TLD), radiophotoluminescence glass dosimeters (RPLD) and NaI(Tl) scintillation survey meters so that the response characteristics of these instruments to cosmic-rays could be clarified. Cosmic-ray contributions for all instruments were correlated with counting rate over 3 MeV by the spectrometer. Each contribution can be estimated by measurement of the counting rate. Conversion factors (nGy/h/cpm) for IC, PIC, TLD, RPLD and NaI survey meters (TCS166 and TCS121C) were 0.33, 0.32, 0.25, 0.24, 0.06 and -0.01, respectively. Self-doses of these instruments were estimated by measurements at Nokogiriyama facilities of the Institute for Cosmic Ray Research, University of Tokyo. Self-doses for TLD and RPLD were approximately 6 nGy/h. The self dose effect should be taken into consideration in environmental dose measurements. These data are expected to be useful in estimating the cosmic-ray contribution and self-dose in the measurement of environmental gamma-ray dose. (author)

Distribution and characteristics of gamma and cosmic ray dose rate in living environment

International Nuclear Information System (INIS)

Nagaoka, Toshi; Moriuchi, Shigeru

1991-01-01

A series of environmental radiation surveys was carried out from the viewpoint of characterizing the natural radiation dose rate distribution in the living environment, including natural and artificial ones. Through the analysis of the data obtained at numbers of places, several aspects of the radiation field in living environments were clarified. That is the gamma ray dose rate varies due to the following three dominant causes: 1) the radionuclide concentration of surrounding materials acting as gamma ray sources, 2) the spatial distribution of surrounding materials, and 3) the geometrical and shielding conditions between the natural gamma ray sources and the measured point; whereas, the cosmic ray dose rate varies due to the thickness of upper shielding materials. It was also suggested that the gamma ray dose rate generally shows an upward tendency, and the cosmic ray dose rate a downward one in artificial environment. This kind of knowledge is expected to serve as fundamental information for accurate and realistic evaluation of the collective dose in the living environment. (author)

Evaluation of exposure to cosmic radiation of flight crews of Lithuanian Airlines

International Nuclear Information System (INIS)

Morkunas, G.; Pilkyte, L.; Ereminas, D.

2003-01-01

In Lithuania the average annual effective dose due to cosmic radiation at the sea level is 0.38 mSv. The dose rate caused by cosmic radiation increases with altitude due to the decrease in attenuation of cosmic radiation by atmosphere. Dose rates altitudes of commercial flights are tens times higher than those at the sea level. For this reason people who frequently fly receive higher doses which might even be subject to legal regulations. The European Council Directive (96/29 EURATOM) on basic radiation safety standards requires that doses of air crews members be assessed and appropriate measures taken, depending on the assessment results. The aim of this study was to evaluate potential doses, which can be received by members of air crews of Lithuania Airlines. The assessment was done by performing measurements and calculations. Measurements were performed in flying aircraft by thermoluminescent detectors, Geiger Muller counters and neutron rem counter. Such an approach lead to evaluation of doses due to directly ionizing particles and neutrons. Calculations were done with the help of the code CARI-6M. Such parameters as flight route, solar activity, duration and altitudes of flight were taken into account. Doses received during different flights and in different air crafts were assessed. The results of measurements and calculations were compared and differences discussed. The results were also compared with the data obtained in other similar studies. It was found that the highest doses are received in flights to Paris, London, Amsterdam, and Frankfurt by aircraft B737. A number of flights causing annual doses higher than 1 mSv was estimated. Despite the fact that only European flights are operated by Lithuanian Airlines the dose of 1 mSv may be exceeded under some circumstances. If it happens some radiation protection measures shall be taken. These measures are also discussed. (author)

Computation of cosmic radiation spectra and application to aircrew dosimetry

International Nuclear Information System (INIS)

Yoo, Song Jae

2002-02-01

Using the Monte Carlo radiation transport code FLUKA- 99, secondary cosmic radiation energy spectra and intensities of neutrons, protons, photons, electrons, and muons were calculated for different geographical latitude and longitude at the commercial jet's altitudes ranging from 27000 ft to 41000 ft. The Badhwar's proton model was used to construct the primary cosmic radiation spectrum and effect of the vertical cutoff rigidity was considered after spectra similar to those given in literature were resulted. By applying the effective dose conversion factors, a calculation tool for aircrew doses was developed. According to the resulting dose rate distribution, effective dose rate over North pole region is around three times of that over equator region due to the geomagnetical shielding effect. Illustrative assessments of aircrew doses were made for four distinctive routes of Korean airliners : Seoul - New York (USA), London (UK), Sydney (Australia) and Mumbai(India). The effective doses to aircrew incurred from a round trip were 0.047, 0.055, 0.018, and 0.018μSv, respectively. If aircrew work 500 hour s a year at the cruise altitude of a international airline, the individual dose would reach 2 mSv which is about the same size as the average annual dose of workers at a nuclear power plant

Investigations of aircrews exposure to cosmic radiation - results, conclusions and suggestions

CERN Document Server

Bilski, P; Horwacik, T; Marczewska, B; Ochab, E; Olko, P

2002-01-01

In frame of a research project undertaken in collaboration with Polish airlines LOT, analysis of aircrews exposure to cosmic radiation has been performed. The applied methods included measurements of radiation doses with thermoluminescent detectors (MTS-N, MCP-N) and track detectors (CR-39) and also calculations of route doses with the CARI computer code. The obtained results indicate that aircrews of nearly all airplanes, with exception of these flying only on ATR aircraft, exceed regularly or may exceed in some conditions, effective doses of 1 mSv. In case of Boeing-767 aircrews such exceeding occurs always, independently of solar activity. Investigations revealed, that during these periods of the solar cycle, when intensity of cosmic radiation is high, exceeding of 6 mSv level is also possible. These results indicate, that according to Polish and European regulations it is necessary for airlines to provide regular estimations of radiation exposure of aircrews. Basing on the obtained results a system for pe...

Assessing exposure to cosmic radiation aboard aircraft: the Sievert system

International Nuclear Information System (INIS)

Bottollier-Depois, J.F.; Biau, A.; Clairand, I.; Saint-Lo, D.; Valero, M.; Blanchard, P.; Dessarps, P.; Lantos, P.

2003-01-01

The study of naturally-occurring radiation and its associated risk is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher on board aircraft that at ground level. Furthermore, its intensity depends on solar activity and eruptions. Due to their professional activity, flight crews and frequent flyers may receive an annual dose of some milli-sieverts. This is why the European directive adopted in 1996 requires the aircraft operators to assess the dose and to inform their flight crews about the risk. The effective dose is to be estimated using various experimental and calculation means. In France, the computerized system for flight assessment of exposure to cosmic radiation in air transport (SIEVERT) is delivered to airlines for assisting them in the application of the European directive. This dose assessment tool was developed by the French General Directorate of Civil Aviation (DGAC) and partners: the Institute for Radiation Protection and Nuclear Safety (IRSN), the Paris Observatory and the French Institute for Polar Research - Paul-Emile Victor (IPEV). This professional service is available on an Internet server accessible to companies with a public section. The system provides doses that consider the routes flown by aircraft Various results obtained are presented. (authors)

Radiation dosimetry for crewmember exposure to cosmic radiation during astronaut training operations

International Nuclear Information System (INIS)

Shavers, M.R.; Gersey, B.B.; Wilkins, R.T.; Semones, E.J.; Cucinotta, F.A.

2003-01-01

'Atmospheric exposures' of astronauts to cosmic ions and secondary particles during air-flight training are being measured and analytically modeled for inclusion in the astronaut medical records database. For many of the ∼170 astronauts currently in the astronaut corps, their occupational radiation exposure history will be dominated by cosmic ion exposures during air-travel rather than short-duration spaceflight. Relatively low (usually <10 μSv hr -1 ) and uniform organ dose rates result from the penetrating mix of cosmic particles during atmospheric exposures at all altitudes, but at rates that vary greatly due to differences in flight profiles and the geomagnetic conditions at the time of flight. The precision and accuracy to which possible deleterious effects of the exposures can be assessed suffers from limitations that similarly impact assessment of human exposures in low-Earth orbit: uncertainties associated with the environmental measurements and their interpretation, uncertainties associated with the analytical tools that transport the cosmic radiation environment, and uncertain biological responses to low-dose-rate exposures to radiation fields of mixed radiation 'quality'. Lineal energy spectra will be measured using a Tissue Equivalent Proportional Counter designed for training and operational sorties frequently flown in T-38, Space Shuttle Trainer, and high altitude WB-57 aircraft. Linear energy spectra will be measured over multiple flights using CR-39 plastic nuclear track detectors, as well. Flight records are available for nearly 200,000 sorties flown in NASA aircraft by astronauts and flight officers in the Johnson Space Center Aircraft Operations Division over the past 25 years, yet this database only partially documents the complete exposure histories. Age-dependent risk analysis indicates significant impact, particularly to young women who anticipate lengthy on-orbit careers

Is cosmic radiation exposure of air crew amenable to control?

International Nuclear Information System (INIS)

McEwan, A.C.

1999-01-01

ICRP Committee 4 currently has a Working Party on Cosmic Ray Exposure in Aircraft and Space Flight. It has assembled information on doses arising in aircraft and space flight and considered the appropriateness of the Commission's recommendations relating to air crew. A central issue is whether the exposures received should be considered amenable to control. Factors of relevance to the enhanced cosmic radiation exposure of air crew, and frequent fliers such as couriers, are doses to pregnant staff, the issue of controllability of doses, and the implementation of regulatory controls. It is concluded that while air crew in the current range of subsonic jet aircraft are exposed to enhanced levels of cosmic radiation, these exposures are not readily controllable nor likely to exceed about 6 mSv/y. The revised ICRP Recommendations in 1991 (ICRP 60) propose air crew be designated as occupationally exposed. However, none of the usual optimisation of dose actions associated with regulation of practices, such as classification of work areas and rules governing working procedures, can be implemented, and in practice the doses are not amenable to control. The International Basic Safety Standards therefore leave this designation to the judgement of national regulatory authorities. One requirement that stems from designation as occupational exposure is that of restriction of doses to pregnant women. Both from the points of view that it is questionable whether exposure of air crew can reasonably be considered to be amenable to control, and the magnitude of the risks from exposures incurred, there is little reason to invoke additional restrictions to limit exposures of pregnant air crew. Copyright (1999) Australasian Radiation Protection Society Inc

Occupational cosmic radiation exposure and cancer in airline cabin crew

International Nuclear Information System (INIS)

Kojo, K.

2013-03-01

Cosmic radiation dose rates are considerably higher at cruising altitudes of airplanes than at ground level. Previous studies have found increased risk of certain cancers among aircraft cabin crew, but the results are not consistent across different studies. Despite individual cosmic radiation exposure assessment is important for evaluating the relation between cosmic radiation exposure and cancer risk, only few previous studies have tried to develop an exposure assessment method. The evidence for adverse health effects in aircrews due to ionizing radiation is inconclusive because quantitative dose estimates have not been used. No information on possible confounders has been collected. For an occupational group with an increased risk of certain cancers it is very important to assess if the risk is related to occupational exposure. The goal of this thesis was to develop two separate retrospective exposure assessment methods for occupational exposure to cosmic radiation. The methods included the assessment based on survey on flight histories and based on company flight timetables. Another goal was to describe the cancer incidence among aircraft cabin crew with a large cohort in four Nordic countries, i.e., Finland, Iceland, Norway, and Sweden. Also the contribution of occupational as well as non-occupational factors to breast and skin cancer risk among the cabin crew was studied with case-control studies. Using the survey method of cosmic radiation exposure assessment, the median annual radiation dose of Finnish airline cabin crew was 0.6 milliSievert (mSv) in the 1960s, 3.3 mSv in the 1970s, and 3.6 mSv in the 1980s. With the flight timetable method, the annual radiation dose increased with time being 0.7 mSv in the 1960 and 2.1 mSv in the 1995. With the survey method, the median career dose was 27.9 mSv and with the timetable method 20.8 mSv. These methods provide improved means for individual cosmic radiation exposure assessment compared to studies where cruder

Occupational cosmic radiation exposure and cancer in airline cabin crew.

Energy Technology Data Exchange (ETDEWEB)

Kojo, K.

2013-03-15

Cosmic radiation dose rates are considerably higher at cruising altitudes of airplanes than at ground level. Previous studies have found increased risk of certain cancers among aircraft cabin crew, but the results are not consistent across different studies. Despite individual cosmic radiation exposure assessment is important for evaluating the relation between cosmic radiation exposure and cancer risk, only few previous studies have tried to develop an exposure assessment method. The evidence for adverse health effects in aircrews due to ionizing radiation is inconclusive because quantitative dose estimates have not been used. No information on possible confounders has been collected. For an occupational group with an increased risk of certain cancers it is very important to assess if the risk is related to occupational exposure. The goal of this thesis was to develop two separate retrospective exposure assessment methods for occupational exposure to cosmic radiation. The methods included the assessment based on survey on flight histories and based on company flight timetables. Another goal was to describe the cancer incidence among aircraft cabin crew with a large cohort in four Nordic countries, i.e., Finland, Iceland, Norway, and Sweden. Also the contribution of occupational as well as non-occupational factors to breast and skin cancer risk among the cabin crew was studied with case-control studies. Using the survey method of cosmic radiation exposure assessment, the median annual radiation dose of Finnish airline cabin crew was 0.6 milliSievert (mSv) in the 1960s, 3.3 mSv in the 1970s, and 3.6 mSv in the 1980s. With the flight timetable method, the annual radiation dose increased with time being 0.7 mSv in the 1960 and 2.1 mSv in the 1995. With the survey method, the median career dose was 27.9 mSv and with the timetable method 20.8 mSv. These methods provide improved means for individual cosmic radiation exposure assessment compared to studies where cruder

Assessing exposure to cosmic radiation aboard aircraft: the SIEVERT system

International Nuclear Information System (INIS)

Bottolier-Depois, J.F.; Clairand, I.; Blanchard, P.; Dessarps, P.; Lantos, P.

2005-01-01

Full text: The study of naturally-occurring radiation and its associated risk is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher on board aircraft that at ground level. Furthermore, its intensity depends on solar activity and eruptions. Due to their professional activity, flight crews and frequent flyers may receive an annual dose of some milliSieverts. This is why the European directive adopted in 1996 requires the aircraft operators to assess the dose and to inform their flight crews about the risk. The effective dose is to be estimated using various experimental and calculation means. In France, the computerized system for flight assessment of exposure to cosmic radiation in air transport (SIEVERT) is delivered to airlines for assisting them in the application of the European directive. This dose assessment tool was developed by the French General Directorate of Civil Aviation (DGAC) and partners: the Institute for Radiation Protection and Nuclear Safety (IRSN), the Paris Observatory and the French Institute for Polar Research - PaulEmile Victor (IPEV). This professional service is available since more than two years on an Internet server accessible to companies with a public section. The system provides doses that consider the routes flown by aircraft. Various results obtained are presented: experimental validation, in particular for the ground level event model (large solar eruption), and statistics on routes and personal doses. (author)

Solar Modulation of Atmospheric Cosmic Radiation:. Comparison Between In-Flight and Ground-Level Measurements

Science.gov (United States)

Iles, R. H. A.; Taylor, G. C.; Jones, J. B. L.

January 2000 saw the start of a collaborative study involving the Mullard Space Science Laboratory, Virgin Atlantic Airways, the Civil Aviation Authority and the National Physical Laboratory in a program to investigate the cosmic radiation exposure to aircrew. The study has been undertaken in view of EU Directive 96/291 (May 2000) which requires the assessment of the level of radiation exposure to aircrew. The project's aims include validation of radiation dose models and evaluation of space weather effects on atmospheric cosmic radiation levels, in particular those effects not accounted for by the models. Ground level measurements are often used as a proxy for variations in cosmic radiation dose levels at aircraft altitudes, especially during Forbush Decreases (FDs) and Solar Energetic Particle (SEP) events. Is this estimation realistic and does the ground level data accurately represent what is happening at altitude? We have investigated the effect of a FD during a flight from Hong Kong to London Heathrow on the 15th July 2000 and compared count rate and dose measurements with simultaneous variations measured at ground level. We have also compared the results with model outputs.

What is cosmic radiation?; Qu'est ce-que le rayonnement cosmique?

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

The earth was indeed receiving ionizing radiations from the heavens. This cosmic radiation consists of particles travelling near the speed of light. It consists of two components, the first of which is permanent and of galactic origin, while the other is more sporadic, depending on the sun's activities. Natural land-based sources expose each of us to an average total dose of 2.4 mSv per year (source UNSCEAR). In addition, the human activities using ionizing radiation contribute to an average annual exposure of 1.4 mSv, originating primarily with medical activities ( radiodiagnostic and radiation therapy). Members of flights crew are subject to exposure. The total dose of cosmic radiation received is is directly proportional with the duration of exposure, and thus with the duration of the flight. Measurement taken on board aircraft during the 1990's showed that flight personnel (on long haul flights) receive an average dose of approximately the same magnitude as the one due to exposure to natural radioactivity in France. The damage caused by ionizing radiation depends on the quantity of energy released by radiation into the cells of each organ or tissue of the human body(exposure dose). For a given quantity of absorbed energy (dose expressed in Gray), the damage will vary according to the nature of the radiation and the affected organ. These effects are of two types: acute effects and deferred effects. Two measurements are essential for radiation protection: the measurements of the dose of radiation absorbed by the body and the assessment of the risk associated with the absorbed dose. Two units were thus created: the gray and the sievert. (N.C.)

Flight attendant radiation dose from solar particle events.

Science.gov (United States)

Anderson, Jeri L; Mertens, Christopher J; Grajewski, Barbara; Luo, Lian; Tseng, Chih-Yu; Cassinelli, Rick T

2014-08-01

Research has suggested that work as a flight attendant may be related to increased risk for reproductive health effects. Air cabin exposures that may influence reproductive health include radiation dose from galactic cosmic radiation and solar particle events. This paper describes the assessment of radiation dose accrued during solar particle events as part of a reproductive health study of flight attendants. Solar storm data were obtained from the National Oceanic and Atmospheric Administration Space Weather Prediction Center list of solar proton events affecting the Earth environment to ascertain storms relevant to the two study periods (1992-1996 and 1999-2001). Radiation dose from exposure to solar energetic particles was estimated using the NAIRAS model in conjunction with galactic cosmic radiation dose calculated using the CARI-6P computer program. Seven solar particle events were determined to have potential for significant radiation exposure, two in the first study period and five in the second study period, and over-lapped with 24,807 flight segments. Absorbed (and effective) flight segment doses averaged 6.5 μGy (18 μSv) and 3.1 μGy (8.3 μSv) for the first and second study periods, respectively. Maximum doses were as high as 440 μGy (1.2 mSv) and 20 flight segments had doses greater than 190 μGy (0.5 mSv). During solar particle events, a pregnant flight attendant could potentially exceed the equivalent dose limit to the conceptus of 0.5 mSv in a month recommended by the National Council on Radiation Protection and Measurements.

COMPARISON OF COSMIC RAYS RADIATION DETECTORS ON-BOARD COMMERCIAL JET AIRCRAFT

Czech Academy of Sciences Publication Activity Database

Kubančák, Ján; Ambrožová, Iva; Pachnerová Brabcová, Kateřina; Jakoubek, J.; Kyselová, D.; Ploc, Ondřej; Bemš, J.; Štěpán, Václav; Uchihori, Y.

2015-01-01

Roč. 164, č. 4 (2015), s. 484-488 ISSN 0144-8420 R&D Projects: GA MŠk(CZ) LG13031 Institutional support: RVO:61389005 Keywords : cosmic radiation * commercial jet aircraft * radiation dose Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.894, year: 2015

Comparison of cosmic rays radiation detectors on-board commercial jet aircraft.

Science.gov (United States)

Kubančák, Ján; Ambrožová, Iva; Brabcová, Kateřina Pachnerová; Jakůbek, Jan; Kyselová, Dagmar; Ploc, Ondřej; Bemš, Július; Štěpán, Václav; Uchihori, Yukio

2015-06-01

Aircrew members and passengers are exposed to increased rates of cosmic radiation on-board commercial jet aircraft. The annual effective doses of crew members often exceed limits for public, thus it is recommended to monitor them. In general, the doses are estimated via various computer codes and in some countries also verified by measurements. This paper describes a comparison of three cosmic rays detectors, namely of the (a) HAWK Tissue Equivalent Proportional Counter; (b) Liulin semiconductor energy deposit spectrometer and (c) TIMEPIX silicon semiconductor pixel detector, exposed to radiation fields on-board commercial Czech Airlines company jet aircraft. Measurements were performed during passenger flights from Prague to Madrid, Oslo, Tbilisi, Yekaterinburg and Almaty, and back in July and August 2011. For all flights, energy deposit spectra and absorbed doses are presented. Measured absorbed dose and dose equivalent are compared with the EPCARD code calculations. Finally, the advantages and disadvantages of all detectors are discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Air crew exposure to cosmic radiation. New analysis, recommendations EURADOS

International Nuclear Information System (INIS)

Spurny, F.; Votockova, I.

1995-01-01

Cosmic radiation on the board of an aircraft consist of two components: directly ionizing radiation (electron, proton - low LET) and neutrons (high LET). Neither composition nor the energy spectrum of usual on-Earth calibration sources ( 60 Co, 252 Cf) do not correspond to the field on a board. Therefore high energy reference fields behind shielding high energy accelerator at CERN and Dubna have been created and intensively studied. Their typical characteristics following from the results of our measurements were obtained. In-flight measurements on the board of commercial aircraft have been realized since 1991 during about 20 flights, Flight routes extended from the 1.3 grad N up to about 65 grad N, flying altitudes varied from 8.2 km to 12.5 km. The exposure level due to galactic cosmic radiation is inversely proportional to the solar activity. Some radiation protection aspects were concluded: (a) The usual limits of annual air crew flight hours correspond at 11.3 km to about 4 mSv per year, with new ICRP conversion factors to about 5 mSv per year; (b) Monthly flight hours limit does not exclude that the exposure of a pregnant women can exceed 1 mSv during this period; (c) The air crew exposure should therefore be checked, controlled a nd administered as conscientiously as for any other group of occupationally exposed persons. A Working group 11 of EURADOS 'Exposure of air crew to cosmic radiation' has been formed (1992-1995) to prepare basic analysis and recommendations concerning the topics. The basic recommendations are the following: (a) air crew flying routinely at altitudes over 8 km are deemed to be category B workers, it is therefore important to estimate, record, control and, where necessary, to limit the doses; (b) the preferred procedure in order to estimate doses to air crew or frequent flyers is to determine route doses and fold these data with data on staff rostering; (c) where doses may exceed the limit for category B workers (6 mSv per year), on

Human population exposure to cosmic radiation

International Nuclear Information System (INIS)

Bouville, A.; Lowder, W.M.

1988-01-01

Critical evaluations of existing data on cosmic radiation in the atmosphere and in interplanetary space have been carried out in order to estimate the exposure of the world's population to this important component of natural background radiation. Data on population distribution and mean terrain heights on a 1 x 1 degree grid have been folded in to estimate regional and global dose distributions. The per caput annual dose equivalent at ground altitudes is estimated to be 270 μSv from charged particles and 50 μSv from neutrons. More than 100 million people receive more than 1 mSv in a year, and two million in excess of 5 mSv. Aircraft flight crews and frequent flyers receive an additional annual dose equivalent in the order of 1 mSv, though the global per caput annual dose equivalent from airplane flights is only about 1 μSv. Future space travellers on extended missions are likely to receive dose equivalents in the range 0.11 Sv, with the possibility of higher doses at relatively high dose rates from unusually large solar flares. These results indicate a critical need for a better understanding of the biological significance of chronic neutron and heavy charged particle exposure. (author)

Measurements and simulations of the radiation exposure to aircraft crew workplaces due to cosmic radiation in the atmosphere

International Nuclear Information System (INIS)

Beck, P.; Latocha, M.; Dorman, L.; Pelliccioni, M.; Rollet, S.

2007-01-01

As required by the European Directive 96/29/Euratom, radiation exposure due to natural ionizing radiation has to be taken into account at workplaces if the effective dose could become more than 1 mSv per year. An example of workers concerned by this directive is aircraft crew due to cosmic radiation exposure in the atmosphere. Extensive measurement campaigns on board aircraft have been carried out to assess ambient dose equivalent. A consortium of European dosimetry institutes within EURADOS WG5 summarized experimental data and results of calculations, together with detailed descriptions of the methods for measurements and calculations. The radiation protection quantity of interest is the effective dose, E (ISO). The comparison of results by measurements and calculations is done in terms of the operational quantity ambient dose equivalent, H*(10). This paper gives an overview of the EURADOS Aircraft Crew In-Flight Database and it presents a new empirical model describing fitting functions for this data. Furthermore, it describes numerical simulations performed with the Monte Carlo code FLUKA-2005 using an updated version of the cosmic radiation primary spectra. The ratio between ambient dose equivalent and effective dose at commercial flight altitudes, calculated with FLUKA-2005, is discussed. Finally, it presents the aviation dosimetry model AVIDOS based on FLUKA-2005 simulations for routine dose assessment. The code has been developed by Austrian Research Centers (ARC) for the public usage (http://avidos.healthphysics.at. (authors)

Levels of external natural radiation and doses to population in Heilongjiang province

International Nuclear Information System (INIS)

Liang Yicheng; He Yongjiang; Wang Lu

1985-01-01

The external natural radiation level in Heilongjiang Province was measured by using China-made FD-71 scintillation radiometers and RSS-111 high pressure ionization chambers. The doses of external radiation to population were also calculated. The population-weighted average value of the absorbed dose rate from terrestrial γ-radiation was 7.2 x 10 -8 Gy.h -1 for outdoors, and 10.8 x 10 -8 Gy.h -1 for indoors. The population-weighted average absorbed dose rate in air from cosmic rays was 3.3 x 10 -8 Gy.h -1 . The annual population-weighted average effective dose equivalent and the annual collective effective dose equivalent from the environmental γ-radiation were 620 μSv and 20.1 x 10 3 man.Sv, respectively. The corresponding figures from cosmic rays were 260 μSv and 8.7 x 10 3 man.Sv, respectively

Biotropic Effect of Radiation Conditions on Orbital Cosmic Stations

Science.gov (United States)

Tsetlin, Vladimir; Ushakov, Igor; Gurieva, Tamar; Moisa, Svetlana; Zotin, Alexei; Lobanov, Alexei

On the orbit of pilot orbital stations the crews undergo to low doses of chronic irradiation of cosmic radiation. The studying of radiobiological effects in different living systems were carried out in the ship’s side (OC “MIR” and ICS) and model surface experiments (power dose 200 mGy/day, density of neutron flow 30 particles/sm2 sec). It was shown that ionized radiation effects on embryonal development of Japanese quail embryo, inducing morphological disturbances in 12% of embryos. Many years ontogenesis (more 15 years of life in OC “MIR”) of microbial association evoked replacement of dominant types of micromycetes and bacterium and increasing of colony-formed units (CFU) in four orders. In laboratory low doses of γ-radiation induced the increasing of flight strain biomass of Aspergillus niger that corresponds to a radiation hormezis and also the increasing of radio-sensitivity. Moreover, under γ-neutron radiation were marked some deviations in morphology of supporting cell and numerous head falls of Aspergillus niger. The irradiation of Protozoa by low doses led to that spontaneous motion activity of spirostoms (Spirostomum ambiguum Ehbg.) accommodated in water processing by mixed γ-neutron radiation decreased twice that testified the fact that the definite factor of γ-neutron radiation effect is the changing of water medium state. In dry seeds of the highest plants wetting in water of preliminary low doses α-and γ-irradiation cells gradually decreased. In hypomagnetic camera the opposite tendency was observed. It is established the phenomena of stimulating effect of low doses of continuous γ-radiation (source of radiation Co60, period of radiation 10 days, average daily power dose 1,5-2,0 mGy, summary dose 15 mGy) on mezenchim stem cells of mice bone brain - a radiation hormezis which revealed in the intensifying of proliferative activity and increasing of number of colony-formed units-F in bone brain in 1,5-4,5 times. Regenerative capacity of

To the exposure of air crew members to cosmic radiation

International Nuclear Information System (INIS)

Spurny, F.; Kovar, I.; Bottollier-Depois, J.F.; Plawinski, L.

1998-01-01

According to an ICRP recommendation, the exposure of jet aircraft crew to radiation should be considered as occupational exposure when the annual equivalent doses are liable to exceed 1 mSv. Many new data on this type of exposure collected since 1991 are presented and analyzed. The dose equivalent rates established are fitted as a function of flight altitude. An analysis of data from cosmic ray monitors has shown that the presence of cosmic rays in the Earth's atmosphere is rather stable since early 1992. An estimation was therefore made of the possible influence of the solar cycle phase by means of a transport code. The results obtained are compared with experimental data

Survey of environmental radiation dose rates in Kyoto and Shiga prefectures, Japan

International Nuclear Information System (INIS)

Minamia, Kazuyuki; Shimo, Michikuni; Oka, Mitsuaki; Ejiri, Kazutaka; Sugino, Masato; Minato, Susumu; Hosoda, Masahiro; Yamada, Junya; Fukushi, Masahiro

2008-01-01

We have measured environmental radiation dose rates in several Prefectures, such as Ai chi Prefecture, Gifu Prefecture, and Mie Prefecture, in central Japan. Recently, we measured the environmental radiation dose rates in Kyoto and Shiga Prefectures that are also located in central Japan with a car-borne survey system. At the time of measurement, Kyoto Prefecture (area: 4,613 km 2 ) had a total of 36 districts, and Shiga Prefecture (area: 3,387 km 2 ) a total of 26. Terrestrial gamma ray dose rates and secondary cosmic ray dose rates were measured by a 2 inches ψ x 2 inches NaI(Tl) scintillation counter and a handy-type altimeter (GPS eTrex Legend by Gamin), respectively. The following factors were taken into consideration the shielding effect of the car body, the effect of the road pavement, radon progeny borne by precipitation, and increases in tunnels and near the walls. Terrestrial gamma ray dose rates in Kyoto and Shiga Prefectures were estimated to be 51.7 ± 6.0 n Gy/h (district average: 52.4 ± 4.7 n Gy/h), 52.2 ± 10.5 n Gy/h (district average: 51.9 ± 8.1 n Gy/h), respectively. Secondary cosmic ray dose rates in Kyoto and Shiga Prefectures were 30.0 ± 0.6 n Gy/h (district average: 29.9 ±0.3 n Gy/h), 30.1 ± 0.3 n Gy/h (district average: 30.0 ± 0.2 n Gy/h), respectively. The environmental radiation dose rates due to the sum dose rates of terrestrial gamma ray and secondary cosmic ray in Kyoto and Shiga Prefectures were 81.7 ± 6.2 n Gy/h (district average: 82.3 ± 4.8 n Gy/h), 82.3 ± 10.6 n Gy/h (district average: 82.0 ± 8.1 n Gy/h), respectively. We confirmed that the environmental radiation dose rates in Kyoto and Shiga Prefectures mainly depended on the change of the terrestrial gamma ray dose rates, since the secondary cosmic ray dose rates had little change. Therefore, radiation dose-rate maps of the terrestrial gamma rays as well as maps of the environmental radiation dose-rate were drawn. (author)

Natural external radiation level and population dose in Hunan province

International Nuclear Information System (INIS)

1985-01-01

A survey of the natural external radiation level in Hunan Province is reported. The measurements were performed with FD-71 scintillation radiometers. On the basis of measurements at about 1,600 locations, the contribution from cosmic radiation is found to be 3.0 x 10 -8 Gy.h -1 , and the average absorbed dose rates in air from terrestrial γ-radiation for outdoors, indoors and roads are determined to be 9.2, 13.1 and 9.0 x 10 -8 Gy.h -1 , respectively. The γ-radiation indoors is markedly higher than that outdoors by a factor of 1.42. The lowest γ-radiation level is found in the sedimentary plain around Donting Lake, while the highest absorbed dose rates in air from terrestrial radiation are observed in some areas with exposed granites. The indoor γ-radiation in brick houses is markedly higher than that in wooden houses. Tarred roads have evidently lower radiation level than sand-gravel roads or concrete roads. The annual effective dose equivalents to the population from cosmic and terrestrial sources are 0.256 and 0.756 mSv, respectively, with a total value of 1.012 mSv

Effects of low doses of ionizing radiation

International Nuclear Information System (INIS)

Anon.

2008-01-01

Ionizing radiation of cosmic or terrestrial origin is part of the environment in which all living things have evolved since the creation of the universe. The artificial radioactivity generated by medical diagnostic and treatment techniques, some industrial activities, radioactive fallout, etc. has now been added to this natural radioactivity. This article reviews the biological effects of the low doses of ionizing radiation to which the population is thus exposed. Their carcinogenic risk cannot simply be extrapolated from what we know about high-dose exposure. (author)

Cosmic radiation exposure of future hypersonic flight missions

International Nuclear Information System (INIS)

Koops, L.

2017-01-01

Cosmic radiation exposure in air traffic grows with flight altitude, geographical latitude and flight time. For future high-speed intercontinental point-to-point travel, the trade-off between reduced flight time and enhanced dose rate at higher flight altitudes is investigated. Various representative (partly) hypersonic cruise missions are considered and in dependence on solar activity the integral route dose is calculated for envisaged flight profiles and trajectories. Our results are compared to those for corresponding air connections served by present day subsonic airliners. During solar maximum, we find a significant reduction in route dose for all considered high-speed missions compared to the subsonic reference. However, during solar minimum, comparable or somewhat larger doses result on transpolar trajectories with (partly) hypersonic cruise at Mach 5. Both solar activity and routing are hence found to determine, whether passengers can profit from shorter flight times in terms of radiation exposure, despite of altitude-induced higher dose rates. Yet, air crews with fixed number of block hours are always subject to larger annual doses, which in the considered cases take values up to five times the reference. We comment on the implications of our results for route planning and aviation decision-making in the absence of radiation shielding solutions. (author)

The estimation of the dose from cosmic radiation received by the population living at mainland of China

International Nuclear Information System (INIS)

Jin Hua; Yue Qingyu

1989-11-01

The measurement of ionization distribution caused by the cosmic ray ionizing components in the air, the survey of population distribution in geography and the investigation of total passengers taking air liners at the mainland of China have been completed. By taking the data from the census of the year 1986 and the population distribution of the mainland, considering the cosmic ray distribution with the height and referring the distribution of neutron flux density in cosmic ray, the population-weighted mean annual effective dose equivalent, which is obtained from 2017 counties and 353 cities, for inhabitants living in every provinces and municipalities directly under Central Government has been calculated. The collective dose equivalent produced by the external exposure of cosmic ray is also estimated when people are taking air liners. The results which are effected by the population distribution show that the annual effective dose equivalant received by the population of China from the cosmic ray is 28% lower than the population of the world. The most of Chinese people are living at the north hemisphere area having lower elevation and geomagnetic latitude, and 53.6% among them is in the area of elevation below 100 m and 91% is in the area of geomagnetic latitude below 30 deg N

To the problem of superfluous cosmic radiation

International Nuclear Information System (INIS)

Savenko, I.A.; Saraeva, M.A.; Shavrin, P.I.

1979-01-01

From consideration of a number of basic works on the excessive cosmic radiation given is the most probable composition (electron, proton, and nuclear components) of this radiation in equatorial regions at altitudes corresponding to minimum altitudes of the drift trajectories hsub(min) <= 0, in case of detecting by detector on the artificial satellite of the Earth (ASE) with the mass up to 1t and of the heavier ASE. The disagreement in spectra of solar cosmic rays obtained along the latitude effect on the ASE. ''Molniya-1'' and in the experiments out of the magnetosphere on the ASE ''Explorer-41'' is explained by excessive radiation production of solar cosmic rays. The comparison of readings of the neutron channel with those of the charged particle channels of the apparatus on the ASE ''Molniya-1'' during the proton event on 25.01.1971 does not contradict to the supposition on the similarity of excessive cosmic radiation production of galactic and solar cosmic rays

Measurement and simulation of the radiation environment in the lower atmosphere for dose assessment

International Nuclear Information System (INIS)

Pioch, Christian Dieter

2012-01-01

Flying personnel is occupationally exposed to rather high radiation levels due to secondary cosmic radiation. Therefore, the radiation environment induced in the lower atmosphere by galactic and solar cosmic radiation was characterized by means of particle transport calculations using GEANT4. These calculations were validated with continuous measurements of the energy spectra of secondary neutrons with Bonner sphere spectrometers at the Zugspitze mountain and near the North Pole. The response of these instruments was determined with GEANT4 and for the first time experimentally verified at high neutron energies (244 and 387 MeV). Route doses for aircrews along typical long-haul flights were determined for galactic and solar cosmic radiation using most recent data on the magnetospheric field and primary cosmic radiation.

Radiation Doses Received by the Irish Population

International Nuclear Information System (INIS)

Colgan, P.A.; Organo, C.; Hone, C.; Fenton, D.

2008-05-01

Some chemical elements present in the environment since the Earth was formed are naturally radioactive and exposure to these sources of radiation cannot be avoided. There have also been additions to this natural inventory from artificial sources of radiation that did not exist before the 1940s. Other sources of radiation exposure include cosmic radiation from outer space and the use of radiation in medical diagnosis and treatment. There can be large variability in the dose received by invividual members of the population from any given source. Some sources of radiation expose every member of the population while, in other cases, only selected individuals may be exposed. For example, natural radioactivity is found in all soils and therefore everybody receives some radiation dose from this activity. On the other hand, in the case of medical exposures, only those who undergo a medical procedure using radiation will receive a radiation dose. The Radiological Protection Institute of Ireland (RPII) has undertaken a comprehensive review of the relevant data on radiation exposure in Ireland. Where no national data have been identified, the RPII has either undertaken its own research or has referred to the international literature to provide a best estimate of what the exposure in Ireland might be. This has allowed the relative contribution of each source to be quantified. This new evaluation is the most up-to-date assessment of radiation exposure and updates the assessment previously reported in 2004. The dose quoted for each source is the annual 'per caput' dose calculated on the basis of the most recently available data. This is an average value calculated by adding the doses received by each individual exposed to a given radiation source and dividing the total by the current population of 4.24 million. All figures have been rounded, consistent with the accuracy of the data. In line with accepted international practice, where exposure takes place both indoors and

Cosmic Radiation Exposure of Future Hypersonic Flight Missions.

Science.gov (United States)

Koops, L

2017-06-15

Cosmic radiation exposure in air traffic grows with flight altitude, geographical latitude and flight time. For future high-speed intercontinental point-to-point travel, the trade-off between reduced flight time and enhanced dose rate at higher flight altitudes is investigated. Various representative (partly) hypersonic cruise missions are considered and in dependence on solar activity the integral route dose is calculated for envisaged flight profiles and trajectories. Our results are compared to those for corresponding air connections served by present day subsonic airliners. During solar maximum, we find a significant reduction in route dose for all considered high-speed missions compared to the subsonic reference. However, during solar minimum, comparable or somewhat larger doses result on transpolar trajectories with (partly) hypersonic cruise at Mach 5. Both solar activity and routing are hence found to determine, whether passengers can profit from shorter flight times in terms of radiation exposure, despite of altitude-induced higher dose rates. Yet, aircrews with fixed number of block hours are always subject to larger annual doses, which in the considered cases take values up to five times the reference. We comment on the implications of our results for route planning and aviation decision-making in the absence of radiation shielding solutions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Measurements of the Cosmic Rays Dose at Different Altitudes of Iran

International Nuclear Information System (INIS)

Faghihi, R.; Mehdizadeh, S.; Jafarizadeh, M.; Sina, S.; Zehtabian, M.; Taheri, M.

2012-01-01

The amount of cosmic rays varies widely with the altitude, latitude and longitude in each region. In this study, the radiation doses due to the cosmic rays were estimated in two steps: in the first step, the neutron and gamma components of the radiation dose were measured for a roundtrip flight on 3 flight routes (Shiraz-Asaluye, Asaluye-Rasht and Shiraz-Mashhad) using a gamma-tracer photon detector and a Thyac 190 N, neutron detector. The minimum values of the measured gamma and neutron doses of 0.15 and 0.04μSv were measured on the Asaluyeh-Shiraz route at the lowest altitude of 19000 ft, while for Rasht-Asaluyeh route at an altitude of 35000 ft those values were found to be 2.52 and 1.09 mSv, respectively. In the second step, a number of air crew members were equipped with thermoluminescence dosimeters (TLD cards) for evaluating the gamma dose and polycarbonate dosimeters (SSNTD) for assessing the neutron dose for one year. The measured value of the annual effective dose received by the crew ranged between 0.5 mSv/y and 1.16 mSv/y, with an average of 0.9 mSv/y for the gamma component and between 0.37 mSv/y and 0.77 mSv/y with an average of 0.61 mSv/y for the neutron component. The results of this investigation are comparable with the investigations that have been conducted in other countries. For instance in UK, the reported annual effective dose of air crew is about 2 mSv, and in Canada, it is estimated to be between 1 to 5 mSv, depending on the flight situations (such as the latitude and longitude of the cities, the flight altitude, etc).

The HZE radiation problem. [highly-charged energetic galactic cosmic rays

Science.gov (United States)

Schimmerling, Walter

1990-01-01

Radiation-exposure limits have yet to be established for missions envisioned in the framework of the Space Exploration Initiative. The radiation threat outside the earth's magnetosphere encompasses protons from solar particle events and the highly charged energetic particles constituting galactic cosmic rays; radiation biology entails careful consideration of the extremely nonuniform patterns of such particles' energy deposition. The ability to project such biological consequences of exposure to energetic particles as carcinogenicity currently involves great uncertainties from: (1) different regions of space; (2) the effects of spacecraft structures; and (3) the dose-effect relationships of single traversals of energetic particles.

Atmospheric ions and pollution. Ions of the cosmic radiation

International Nuclear Information System (INIS)

Cachon, A.

1977-01-01

The principal historical steps before the so-called 'cosmic radiation' was known as an extra-terrestrial radiation are described. The origin, nature and energy of the radiation are discussed together with its evolution all along its path through atmosphere, in view of the interaction that occurs between the radiation and the atmosphere. The mechanism of the ionization induced by cosmic radiation is analyzed, the corresponding energy balance is established and the possible singularities in air ionization induced by cosmic rays are discussed [fr

The absorbed dose in air of photons generated from secondary cosmic rays at sea level at Nagoya, Japan

International Nuclear Information System (INIS)

Akhmad, Y.R.

1995-01-01

Investigations have been carried out to determine the absorbed dose in air of photons generated from secondary cosmic radiation at sea level at Nagoya, Japan. To isolate the contribution from cosmic photons, the pulse-height distributions due to μ particles and electrons were eliminated from the observed pulse-height distribution of a measurement with a 3'' diam. spherical NaI(Tl) detector. The pulse height due to μ particles and electrons was inferred from the coincidence technique using two types of scintillation detectors with different sensitivities to photons. To obtain the photon fluence rate for further dose calculation, the pulse-height distribution of cosmic photons was unfolded by the iterative method. The mean and its standard deviation of the absorbed dose in air and fluence rate due to cosmic photons calculated from a one year observation are 2.86±0.05 nGy.h -1 and 0.1342±0.0015 photons.cm -2 .s -1 , respectively. The absorbed dose in air from cosmic photons was 0.5% lower during autumn to winter and 0.6% higher during spring to summer than the mean taken over the year. (author)

Level of natural background radiation and dose to population in Zhejiang Province

International Nuclear Information System (INIS)

Zhao Yifang; Chen Guopei; Wang Zanxin; Ma Mingqiang

1994-01-01

The natural background radiation in Zhejiang Province was measured and the dose to population was estimated. The results showed that the population-weighted average values of the absorbed dose rate in air from cosmic ray ionization were 3.0 x 10 -8 Gy·h -1 outdoors and 2.7 x 10 -8 Gy·h -1 indoors. The average absorbed dose rates in air from terrestrial γ-radiation were 9.1 x 10 -8 Gy·h -1 outdoors and 14.9 x 10 -8 Gy·h -1 indoors. The average values of radon in air were 17.2 Bq· -3 indoors and 12.7 Bq·m -8 outdoors. The contents of natural radionuclides in food and water were measured. The total annual individual average effective dose from natural background radiation was about 2.0 mSv. The contributions of cosmic rays, terrestrial radiation radon and thoron daughters exposure in air and internal exposure within the body were about 0.24, 0.77, 0.67 and 0.35 mSv, respectively. The annual collective effective dose to population in the province was estimated to be 8.5 x 10 4 man Sv·a -1

Estimation of effective dose to public from external exposure to natural background radiation in saudi arabia

International Nuclear Information System (INIS)

Khalid, A. A.

2003-01-01

The effective dose values in sixteen cities in Saudi Arabia due to external exposure to natural radiation were evaluated. These doses are based on natural background components including external exposure to terrestrial radiation and cosmic rays. The importance of evaluating the effective dose to the public due to external exposure to natural background radiation lies in its epidemiological and dosimetric importance and in forming a basis for the assessment of the level of radioactive contamination or pollution in the environment in the future. The exposure to terrestrial radiation was measured using thermoluminescent dosimeters (TLD). The exposure from cosmic radiation was determined using empirical correlation. The values evaluated for the total annual effective dose in all cities were within the world average values. The highest total annual effective dose measured in Al-Khamis city was 802 μSv/y, as compared to 305 μSv/y in Dammam city, which was considered the lowest value

Natural radiation dose to Gammarus from Hudson river

International Nuclear Information System (INIS)

Paschoa, A.S.; Wrenn, M.E.; Eisenbud, M.

1979-01-01

The purpose of this investigation is to evaluate the natural radiation dose rate to whole body and components of the Gammarus species, a zooplankton which occurs in the Hudson River among other places, and to compare the results with the upper limits of dose rates from man-made sources. The alpha dose rates to the exoskeleton and soft tissues are about 10 times the average alpha dose rate to the whole body, assuming uniform distribution of 226 Ra. The natural alpha radiation dose rate to Gammarus represents only about 5% of the total natural dose to the organism, i.e., 492 mrad/yr. The external dose rate due to 40 K, 238 U plus daughters and 232 Th plus daughters accumulated in the sediments comprise 91% of that total natural dose rate, the remaining percentage being due to natural internal beta emitters and cosmic radiation. Man-made sources can cause an external dose rate up to 224 mrad/yr, which comprises roughly 1/3 of the total dose rate (up to 716 mrad/yr; natural plus man-made) to the Gammarus of Hudson River in front of Indian Point Nuclear Power Station. However, in terms of dose-equivalent the natural sources of radiation would contribute more than 75% of the total dose to Gammarus

Cosmic rays and radiations from the cosmos

International Nuclear Information System (INIS)

Parizot, E.

2005-12-01

This document gathers a lot of recent information concerning cosmic radiations, it is divided into 4 parts. Part I: energy, mass and angular spectra of cosmic rays. Part II: general phenomenology of cosmic rays, this part deals with the standard model, the maximal energy of protons inside supernova remnants, nucleosynthesis of light elements, and super-bubbles. Part III: radiations from the cosmos, this part deals with high energy gamma rays, non-thermal radiation of super-bubbles, positron transport, and the Compton trail of gamma-ray bursts. Part IV: the Pierre Auger observatory (OPA), this part deals with the detection of gamma ray bursts at OPA, the measurement of anisotropy, and top-down models. (A.C.)

Cosmic gamma-ray background radiation. Current understandings and problems

International Nuclear Information System (INIS)

Inoue, Yoshiyuki

2015-01-01

The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space telescope has recently measured it at 0.1-820 GeV and revealed that the cosmic GeV gamma-ray background is composed of blazars, radio galaxies, and star-forming galaxies. However, Fermi still leaves the following questions. Those are dark matter contribution, origins of the cosmic MeV gamma-ray background, and the connection to the IceCube TeV-PeV neutrino events. In this proceeding, I will review the current understandings of the cosmic gamma-ray background and discuss future prospects of cosmic gamma-ray background radiation studies. (author)

A study of the terrestrial and cosmic gamma-rays in Jordan

International Nuclear Information System (INIS)

Mansi, M. A.

1996-01-01

Natural terrestrial gamma and cosmic radiations dose rates in Jordan were measured during a period of three years in thirty four stations distributed over all Jordanian territories using the thermoluminescence dosimeter(TLD) Coso 4 :Tm. The average absorbed dose rates in air from terrestrial gamma and cosmic radiations were found to vary from(57 ±3;9) n Gy/hr in Assafi to (350 ± 14; 42) n Gy/hr in Manjam Alhisa. The mean dose rate due to terrestrial gamma radiations was found to be equal to (55 ± 2; 13) nGy/hr, and that due to cosmic radiations was calculated to be(35 ± 1;4) n Gy/hr. The annual effective dose equivalent from terrestrial and cosmic gamma radiations was found to be equal to(0.65±0.02; 0.12)mSv/year. It was found that the absorbed dose rate due to cosmic radiations in Jordan can be fitted by the formula, D c osmic=27+5.2 h+1.86 h 2 where h is the altitude reference to the Dead Sea measured in km. 19 refs., 17 figs., 6 tabs.(Author)

Cosmic radiation exposure and persistent cognitive dysfunction

Science.gov (United States)

Parihar, Vipan K.; Allen, Barrett D.; Caressi, Chongshan; Kwok, Stephanie; Chu, Esther; Tran, Katherine K.; Chmielewski, Nicole N.; Giedzinski, Erich; Acharya, Munjal M.; Britten, Richard A.; Baulch, Janet E.; Limoli, Charles L.

2016-01-01

The Mars mission will result in an inevitable exposure to cosmic radiation that has been shown to cause cognitive impairments in rodent models, and possibly in astronauts engaged in deep space travel. Of particular concern is the potential for cosmic radiation exposure to compromise critical decision making during normal operations or under emergency conditions in deep space. Rodents exposed to cosmic radiation exhibit persistent hippocampal and cortical based performance decrements using six independent behavioral tasks administered between separate cohorts 12 and 24 weeks after irradiation. Radiation-induced impairments in spatial, episodic and recognition memory were temporally coincident with deficits in executive function and reduced rates of fear extinction and elevated anxiety. Irradiation caused significant reductions in dendritic complexity, spine density and altered spine morphology along medial prefrontal cortical neurons known to mediate neurotransmission interrogated by our behavioral tasks. Cosmic radiation also disrupted synaptic integrity and increased neuroinflammation that persisted more than 6 months after exposure. Behavioral deficits for individual animals correlated significantly with reduced spine density and increased synaptic puncta, providing quantitative measures of risk for developing cognitive impairment. Our data provide additional evidence that deep space travel poses a real and unique threat to the integrity of neural circuits in the brain. PMID:27721383

Cosmic microwave background radiation

International Nuclear Information System (INIS)

Wilson, R.W.

1979-01-01

The 20-ft horn-reflector antenna at Bell Laboratories is discussed in detail with emphasis on the 7.35 cm radiometer. The circumstances leading to the detection of the cosmic microwave background radiation are explored

Cosmic radiation during air travel: trends in exposure of aircrews and airline passengers

NARCIS (Netherlands)

Blaauboer RO; LSO

2004-01-01

An unfavourable effect of flying is the enhanced exposure of both passengers and aircrew to cosmic radiation at high altitudes. On the basis of a detailed survey on passengers arriving at or departing from Amsterdam Schiphol Airport in the 1988-1997 period, estimates of individual effective dose for

Preliminary study on the measurement of background radiation dose at Antarctica during 32nd expedition

International Nuclear Information System (INIS)

Bakshi, A.K.; Pal, Rupali; Chougaonkar, M.P.; Dhar, Ajay

2013-01-01

A significant proportion (10%) of the natural background radiation is of cosmic origin. Cosmic ray consists of gamma, protons, electrons, pions, muons, neutrons and low Z nuclei. Due to the geomagnetic effect, cosmic radiation levels at poles are higher. As a consequence, personnel working in Antarctica (or Arctic) are subjected to high level of cosmic radiation. The present study gives the details of the estimation of background radiation (neutrons, gamma and electrons) dose rate around the Indian station at Antarctica named 'Bharati' measured during 32 nd Indian scientific expedition to Antarctica (32 nd INSEA). The measurement was carried out by passive dosimeters such as TLDs and CR-39 and active dosimeter such as RadEye G portable gamma survey meter. Gamma and electron components were measured using TLDs and survey meter, whereas CR-39 SSNTDs and neutron sensitive TLDs were used for neutron measurements. These detectors were deployed at few selected locations around Bharati station for about 2½ months during summer expedition. The neutron detectors used in the study were pre-calibrated with 241 Am-Be fast/thermal neutron source. The fast neutron dose rate measured based on CR-39 detector was found to about 140-420 nSv/h. The gamma dose rate evaluated by TLDs/survey meter are in the range of 290-400 nSv/h. (author)

Atmospheric radiation flight dose rates

Science.gov (United States)

Tobiska, W. K.

2015-12-01

Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.

Dosimetric significance of cosmic radiation in the altitude of SST and in free space

Energy Technology Data Exchange (ETDEWEB)

Allkofer, O C [Kiel Univ. (Germany, F.R.). Inst. fuer Reine und Angewandte Kernphysik

1977-01-01

The integral cosmic-ray flux, and hence the dose rate, increases with altitude. At the cruising altitude of the subsonic jets, about 10 km, the dose rate is already about a factor 70 higher than at sea level. At the higher altitudes of SST the situation is different because the composition of the galactic component differs from that at the subsonic level, the solar flares are more efficient, and a small number of heavy nuclei are still present. In free space an additional radiation hazard appears when the radiation belts have to be crossed.

Preliminary results of measurement of natural environmental radiation levels and doses to population in China

International Nuclear Information System (INIS)

Wang Qiliang; He Miaoting; Shu Qi

1985-01-01

In this paper the preliminary results of measurement of natural environmental radiation levels in China with RSS-111 high pressure ionization chamber and estimated doses to population are reported. A total of 2,723 indoor locales throughout China were measured. The results showed that the average absorbed dose rates in air due to gamma radiation for indoors and outdoors were 11.0 x 10 -8 Gy.h -1 and 7.4 x 10 -8 Gy.h -1 , respectively, and those due to cosmic rays were 3.2 x 10 -8 Gy.h -1 and 3.7 x 10 -8 Gy.h -1 , respectively. The annual average effective dose equivalent to population was 919 μSv, including 630 μSv from natural gamma radiation and 289 μSv from cosmic rays

Transition-radiation detectors for cosmic-ray research

International Nuclear Information System (INIS)

Mueller, D.; Chicago Univ., Ill.

1975-01-01

Transition-radiation detectors for cosmic-ray work are described which consist of plastic foam of multiple plastic foil radiators, followed by proportional chambers. A summary of the properties of such detectors is given, and the detection and discrimination efficiencies for energetic particles are discussed. Several possible applications of such devices for studies of cosmic-ray particles in the energy region γ=E/mc 2 >10 3 are advertised

Investigation of Contributions of Cosmic Radiation to Background Dose with Altitude at Ahmadu Bello University, Zaria, Nigeria

International Nuclear Information System (INIS)

Uwaechia, F.C.; Zakari, Y.I.; Ibeanu, I.G.E.

2014-01-01

This study investigated the contributions of cosmic radiation to background dose at Ahmadu Bello University, Zaria, Nigeria using two portable survey meters (Rados -120 and FH 40F2 ). The work was conducted in two phases (dry and rainy seasons).The recorded gamma dose rates were observed to proportionally increase with increase in altitude, that is from ground floor (altitude 3.52 m above sea level) to the eight floor (altitude 30.08 m above sea level). In a similar manner, there were observed variations in the seasonal results-the dry season data were consistently higher than the rainy season data. The mean measured indoor and outdoor gamma dose rates for the two seasons (rainy and dry seasons) were 210.0nSv/h and 279.4nSv/h, and 231.3nSv/h and 368.8nSv/h at the ground floor and the eight floor, respectively. The rainy season result repeated itself on a particular very heavy rainy day with a mean measured gamma dose rate of 204.4nSv/h and 267.4nSv/h at the ground floor and eight floor, respectively. The annual indoor and outdoor mean effective dose for a 1000hour working period was calculated as 0.32 μSv and 0.35 μSv at the ground floor and 0.68 μSv and 0.76 μSv the 8 th floor, respectively (for inside and outside the building).

Dosemetry for exposures to cosmic radiation in civilian aircraft - Part 1: Conceptual basis for measurements

International Nuclear Information System (INIS)

2006-01-01

Aircraft crew are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60, the European Union (EU) introduced a revised Basic Safety Standards Directive, which included exposure to natural sources of ionizing radiation, including cosmic radiation, as occupational exposure. The Directive requires account to be taken of the exposure of aircraft crew liable to receive more than 1 mSv per year. It then identifies the following four protection measures: (i) to assess the exposure of the crew concerned; (ii) to take into account the assessed exposure, when organizing working schedules with a view to reducing the doses of highly exposed crew; (iii) to inform the workers concerned of the health risks their work involves; and (iv) to apply the same special protection during pregnancy to female crew in respect of the 'child to be born' as to other female workers. The EU Council Directive has already been incorporated into laws and regulations of EU Member States and is being included in the aviation safety standards and procedures of the Joint Aviation Authorities and the European Air Safety Agency. For regulatory and legislative purposes, the radiation protection quantities of interest are equivalent dose (to the foetus) and effective dose. The cosmic radiation exposure of the body is essentially uniform and the maternal abdomen provides no effective shielding to the foetus. As a result, the magnitude of equivalent dose to the foetus can be put equal to that of the effective dose received by the mother. Doses on board aircraft are generally predictable, and events comparable to unplanned exposure in other radiological workplaces cannot normally occur (with the rare exceptions of extremely intense and energetic solar particle events). Personal dosemeters for

Does electromagnetic radiation accelerate galactic cosmic rays

Science.gov (United States)

Eichler, D.

1977-01-01

The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

Cosmic radiation dosimetry onboard aircrafts at the brazilian airspace

International Nuclear Information System (INIS)

Federico, Claudio Antonio

2011-01-01

The objective of this work is the establishment of a dosimetric system for the aircrew in the domestic territory. A technique to perform measurements of ambient dose equivalent in aircrafts was developed. An active detector was evaluated for onboard aircraft use, testing its adequacy to this specific type of measurement as well as its susceptibility to the magnetic and electromagnetic interferences. The equipment was calibrated in standard radiation beams and in a special field of the European Laboratory CERN, that reproduces with great proximity the real spectrum in aircraft flight altitudes; it was also tested in several flights, in an Brazilian Air Force's aircraft. The results were evaluated and compared with those obtained from several computational programs for cosmic radiation estimates, with respect to its adequacy for use in the South American region. The program CARI-6 was selected to evaluate the estimated averaged effective doses for the aircrew who operate in this region. A statistical distribution of aircrew effective doses in South America and Caribe was made, and the results show that a great part of this aircrew members are subjected to annual effective doses that exceed the dose limits for the members of the public. Additionally, a preliminary passive dosemeter, based in thermoluminescent detectors, was proposed; international collaborations with United Kingdom and Italy were established for joint measurements of the ambient equivalent doses in aircrafts. (author)

The 3D Radiation Dose Analysis For Satellite

Science.gov (United States)

Cai, Zhenbo; Lin, Guocheng; Chen, Guozhen; Liu, Xia

2002-01-01

the earth. These particles come from the Van Allen Belt, Solar Cosmic Ray and Galaxy Cosmic Ray. They have different energy and flux, varying with time and space, and correlating with solar activity tightly. These particles interact with electrical components and materials used on satellites, producing various space radiation effects, which will damage satellite to some extent, or even affect its safety. orbit. Space energy particles inject into components and materials used on satellites, and generate radiation dose by depositing partial or entire energy in them through ionization, which causes their characteristic degradation or even failure. As a consequence, the analysis and protection for radiation dose has been paid more attention during satellite design and manufacture. Designers of satellites need to analyze accurately the space radiation dose while satellites are on orbit, and use the results as the basis for radiation protection designs and ground experiments for satellites. can be calculated, using the model of the trapped proton and the trapped electron in the Van Allen Belt (AE8 and AP8). This is the 1D radiation dose analysis for satellites. Obviously, the mass shielding from the outside space to the computed point in all directions is regarded as a simple sphere shell. The actual structure of satellites, however, is very complex. When energy particles are injecting into a given equipment inside satellite from outside space, they will travel across satellite structure, other equipment, the shell of the given equipment, and so on, which depends greatly on actual layout of satellite. This complex radiation shielding has two characteristics. One is that the shielding masses for the computed point are different in different injecting directions. The other is that for different computed points, the shielding conditions vary in all space directions. Therefore, it is very difficult to tell the differences described above using the 1D radiation analysis, and

Level of natural background radiation and dose to population in Heilongjiang province

International Nuclear Information System (INIS)

Liang Yicheng; Wang Lu; He Yongjiang

1992-01-01

The natural background radiation in Heilongjiang Province was measured and the population dose was estimated. The results showed that the population-weighted average values of the absorbed dose rate in air from cosmic ray ionization were 3.3 ± 10 -8 Gy·h -1 outdoors and 3.0 x 10 -8 Gy·h -1 indoors. The average values of radon in air were 11.3 Bq·m -3 outdoors and 20.8 Bq·m -3 indoors. The average concentrations of natural radionuclides U, Th, 226 Ra, and 40 K were 6.1 x 10 -2 , 1.1 x 10 -2 , 8.4 x 10 -2 , and 68.9 Bq·kg -1 respectively in food, and 4.8 x 10 -2 , 2.0 x 10 -4 , 1.2 x 10 -2 and 4.6 x 10 -2 Bq·L -1 respectively in drinking water. The total annual individual average effective dose equivalents from natural background radiation were about 2200 μSv. Among them the contributions of cosmic rays, terrestrial radiation, radon and thoron daughters exposure in air, internal exposure within the body were about 320, 630, 860, and 390 μSv, respectively

Cosmic Radiation and Aircrew Exposure: Implementation of European Requirements in Civil Aviation, Dublin, 1-3 July 1998

Science.gov (United States)

Talbot, Lee

1999-03-01

The European Union's Basic Safety Standards Directive (96/29/Euratom) lays down safety standards for the protection of workers and the general public against the effects of ionising radiations. Article 42 of the Directive deals with the protection of aircrew. It states that for crew of jet aircraft who are likely to be subject to exposure to more than 1 mSv y-1 appropriate measures must be taken, in particular: to assess the exposure of the crew concerned, to take into account the assessed exposure when organising working schedules with a view to reducing the doses of highly exposed aircrew, to inform concerned workers of the health risks involved in their work, to apply Article 10 to female aircrew. (The unborn child shall be treated like a member of the public.) This Directive must be transformed into national law of the 15 member states of the European Union by 13 May 2000. The European Commission and the Radiological Protection Institute of Ireland sponsored this International Conference. The objective of this conference was to assist both the airline industry and the national regulatory organisations in identifying the means available to comply with the requirements of the Directive. Over 200 delegates attended the conference from more than 25 countries. The welcoming addresses were made by Mary Upton (Director of the Radiological Protection Institute of Ireland), Joe Jacob (Minister for State responsible for Nuclear Safety) and James Currie (Director-General for the Environment, Nuclear Safety and Civil Protection). Mr Currie stated that there was a need for political decisions to be based on good science, and that technological trends will lead to higher and longer flights, and therefore higher radiation doses. The first day concentrated on the scientific basis of measurement, calculation and monitoring of cosmic radiation. The first speaker, Dr Heinrich from the University of Siegen, Germany, talked about the physics of cosmic radiation fields. He pointed

Atmospheric radiation modeling of galactic cosmic rays using LRO/CRaTER and the EMMREM model with comparisons to balloon and airline based measurements

Science.gov (United States)

Joyce, C. J.; Schwadron, N. A.; Townsend, L. W.; deWet, W. C.; Wilson, J. K.; Spence, H. E.; Tobiska, W. K.; Shelton-Mur, K.; Yarborough, A.; Harvey, J.; Herbst, A.; Koske-Phillips, A.; Molina, F.; Omondi, S.; Reid, C.; Reid, D.; Shultz, J.; Stephenson, B.; McDevitt, M.; Phillips, T.

2016-09-01

We provide an analysis of the galactic cosmic ray radiation environment of Earth's atmosphere using measurements from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) aboard the Lunar Reconnaissance Orbiter (LRO) together with the Badhwar-O'Neil model and dose lookup tables generated by the Earth-Moon-Mars Radiation Environment Module (EMMREM). This study demonstrates an updated atmospheric radiation model that uses new dose tables to improve the accuracy of the modeled dose rates. Additionally, a method for computing geomagnetic cutoffs is incorporated into the model in order to account for location-dependent effects of the magnetosphere. Newly available measurements of atmospheric dose rates from instruments aboard commercial aircraft and high-altitude balloons enable us to evaluate the accuracy of the model in computing atmospheric dose rates. When compared to the available observations, the model seems to be reasonably accurate in modeling atmospheric radiation levels, overestimating airline dose rates by an average of 20%, which falls within the uncertainty limit recommended by the International Commission on Radiation Units and Measurements (ICRU). Additionally, measurements made aboard high-altitude balloons during simultaneous launches from New Hampshire and California provide an additional comparison to the model. We also find that the newly incorporated geomagnetic cutoff method enables the model to represent radiation variability as a function of location with sufficient accuracy.

Anisotropy of the cosmic background radiation

International Nuclear Information System (INIS)

Silk, J.

1988-01-01

The characteristics of the cosmic microwave background radiation (CBR) are reviewed, focusing on intrinsic anisotropies caused by primordial matter fluctuations. The basic elements of the CBR are outlined and the contributions to anisotropy at different angular scales are discussed. Possible fluctuation spectra that can generate the observed large-scale structure of the universe through gravitational instability and nonlinear evolution are examined and compared with observational searches for cosmic microwave anisotropies. 21 refs

Search for Antihelium in the Cosmic Radiation

DEFF Research Database (Denmark)

Streitmatter, R.E.; Barbier, L.M.; Christian, E.R.

1996-01-01

The balloon-borne Isotope Matter-Antimatter Experiment (IMAX) was flown from Lynn Lake, Manitoba Canada on July 16-17, 1992. Sixteen hours of data were taken. Measurements of multiple dE/dX, rigidity, and time of flight were used to search for antihelium in the cosmic radiation. A report on the r......The balloon-borne Isotope Matter-Antimatter Experiment (IMAX) was flown from Lynn Lake, Manitoba Canada on July 16-17, 1992. Sixteen hours of data were taken. Measurements of multiple dE/dX, rigidity, and time of flight were used to search for antihelium in the cosmic radiation. A report...

Aircrew Exposure from Cosmic Radiation on Commercial Airline Routes

Energy Technology Data Exchange (ETDEWEB)

Lewis, B.J.; McCall, M.J.; Green, A.R.; Bennett, L.G.I.; Pierre, M.; Schrewe, U.J.; O' Brien, K.; Felsberger, E

2001-07-01

As a result of the recent recommendations of the ICRP 60, and in anticipation of possible regulation on occupational exposure of Canadian-based aircrew, an extensive study was carried out by the Royal Military College of Canada over a one-year period to measure the cosmic radiation at commercial jet altitudes. A tissue-equivalent proportional counter was used to measure the ambient total dose equivalent rate on 62 flight routes, resulting in over 20,000 data points at one-minute intervals at various altitudes and geomagnetic latitudes (i.e. which span the full cut-off rigidity of the Earth's magnetic field). These data were then compared to similar experimental work at the Physikalisch Technische Bundesanstalt, using a different suite of equipment, to measure separately the low and high linear energy transfer components of the mixed radiation field, and to predictions with the LUIN transport code. All experimental and theoretical results were in excellent agreement. From these data, a semi-empirical model was developed to allow for the interpolation of the dose rate for any global position, altitude and date (i.e. heliocentric potential). Through integration of the dose rate function over a great circle flight path, a computer code was developed to provide an estimate of the total dose equivalent on any route worldwide at any period in the solar cycle. (author)

Thick Galactic Cosmic Radiation Shielding Using Atmospheric Data

Science.gov (United States)

Youngquist, Robert C.; Nurge, Mark A.; Starr, Stanley O.; Koontz, Steven L.

2013-01-01

NASA is concerned with protecting astronauts from the effects of galactic cosmic radiation and has expended substantial effort in the development of computer models to predict the shielding obtained from various materials. However, these models were only developed for shields up to about 120 g!cm2 in thickness and have predicted that shields of this thickness are insufficient to provide adequate protection for extended deep space flights. Consequently, effort is underway to extend the range of these models to thicker shields and experimental data is required to help confirm the resulting code. In this paper empirically obtained effective dose measurements from aircraft flights in the atmosphere are used to obtain the radiation shielding function of the earth's atmosphere, a very thick shield. Obtaining this result required solving an inverse problem and the method for solving it is presented. The results are shown to be in agreement with current code in the ranges where they overlap. These results are then checked and used to predict the radiation dosage under thick shields such as planetary regolith and the atmosphere of Venus.

Mutational influences of low-dose and high let ionizing radiation in drosophila melanogaster

Science.gov (United States)

Lei, Huang; Fanjun, Kong; Sun, Yeqing

For cosmic environment consists of a varying kinds of radiation particles including high Z and energy ions which was charactered with low-dose and high RBE, it is important to determine the possible biofuctions of high LET radiation on human beings. To analyse the possible effectes of mutational influences of low-dose and high-LET ionizing radiation, wild fruit flies drosophila melanogaster were irradiated by 12C6+ ions in two LET levels (63.3 and 30 keV/µum) with different low doses from 2mGy to 2000mGy (2, 20, 200, 2000mGy) in HIRFL (Heavy ion radiation facility laboratory, lanzhou, China).In the same LET value group, the average polymorphic frequency was elevated along with adding doses of irradation, the frequency in 2000 mGy dose samples was significantly higher than other samples (p<0.01).These results suggest that genomic DNA sequence could be effected by low-dose and high-LET ionizing radiation, the irradiation dose is an important element in genomic mutation frequency origination.

Dose assessment on natural radiation, natural radionuclide, and artificial radionuclide released by Fukushima nuclear accident

International Nuclear Information System (INIS)

Hosoda, Masahiro; Tokonami, Shinji; Furukawa, Masahide

2012-01-01

Various radionuclides are distributed in environmental materials such as soil, rock, and water. People are exposed every day to natural radiation. According to the UNSCEAR 2008 report, Sources of Ionizing Radiation, natural radiation sources are categorized as terrestrial gamma-rays, radon, cosmic rays and food. The effective dose from radon, thoron and its decay products is about 50% of all natural radiation exposure. Consciousness of the Japanese public toward radiation exposure has significantly increased since the start of the Fukushima Dai-ichi Nuclear Power Station accident. In this paper, the nationwide survey and dose estimation for terrestrial gamma-rays and radon are summarized. External dose from artificial radionuclides released by the Fukushima accident are also reported. (author)

Cosmic Radiation - An Aircraft Manufacturer's View

International Nuclear Information System (INIS)

Hume, C.

1999-01-01

The relevance and context of cosmic radiation to an aircraft maker Airbus Industrie are outlined. Some future developments in aircraft and air traffic are described, along with their possible consequences for exposure. (author)

On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: I. Cosmic microwave background radiation

Science.gov (United States)

Fisenko, Anatoliy I.; Lemberg, Vladimir

2014-07-01

Using the explicit form of the functions to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies v 1≤ v≤ v 2 are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60-600 GHz frequency interval at the temperature T=2.72548 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant σ are calculated. In the case of the dipole spectrum, the constants a and σ, and the radiative and thermodynamic properties of the CMB radiation are obtained using the mean amplitude T amp=3.358 mK. It is shown that the Doppler shift leads to a renormalization of the radiation density constant a, the Stefan-Boltzmann constant σ, and the corresponding constants for the thermodynamic functions. The expressions for new astrophysical parameters, such as the entropy density/Boltzmann constant, and number density of CMB photons are obtained. The radiative and thermodynamic properties of the Cosmic Microwave Background radiation for the monopole and dipole spectra at redshift z≈1089 are calculated.

DNDO Report: Predicting Solar Modulation Potentials for Modeling Cosmic Background Radiation

Energy Technology Data Exchange (ETDEWEB)

Behne, Patrick Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-08-08

The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere and inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulation potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence, and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.

Global real-time dose measurements using the Automated Radiation Measurements for Aerospace Safety (ARMAS) system

Science.gov (United States)

Tobiska, W. Kent; Bouwer, D.; Smart, D.; Shea, M.; Bailey, J.; Didkovsky, L.; Judge, K.; Garrett, H.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R.; Bell, D.; Mertens, C.; Xu, X.; Wiltberger, M.; Wiley, S.; Teets, E.; Jones, B.; Hong, S.; Yoon, K.

2016-11-01

The Automated Radiation Measurements for Aerospace Safety (ARMAS) program has successfully deployed a fleet of six instruments measuring the ambient radiation environment at commercial aircraft altitudes. ARMAS transmits real-time data to the ground and provides quality, tissue-relevant ambient dose equivalent rates with 5 min latency for dose rates on 213 flights up to 17.3 km (56,700 ft). We show five cases from different aircraft; the source particles are dominated by galactic cosmic rays but include particle fluxes for minor radiation periods and geomagnetically disturbed conditions. The measurements from 2013 to 2016 do not cover a period of time to quantify galactic cosmic rays' dependence on solar cycle variation and their effect on aviation radiation. However, we report on small radiation "clouds" in specific magnetic latitude regions and note that active geomagnetic, variable space weather conditions may sufficiently modify the magnetospheric magnetic field that can enhance the radiation environment, particularly at high altitudes and middle to high latitudes. When there is no significant space weather, high-latitude flights produce a dose rate analogous to a chest X-ray every 12.5 h, every 25 h for midlatitudes, and every 100 h for equatorial latitudes at typical commercial flight altitudes of 37,000 ft ( 11 km). The dose rate doubles every 2 km altitude increase, suggesting a radiation event management strategy for pilots or air traffic control; i.e., where event-driven radiation regions can be identified, they can be treated like volcanic ash clouds to achieve radiation safety goals with slightly lower flight altitudes or more equatorial flight paths.

Separation of the Galactic Cosmic Rays and Inner Earth Radiation Belt Contributions to the Daily Dose Onboard the International Space Station in 2005-2011

Science.gov (United States)

Lishnevskii, A. E.; Benghin, V. V.

2018-03-01

The DB-8 detectors of the ISS radiation monitoring system (RMS) have operated almost continuously onboard the ISS service module since August 2001 till December 2014. The RMS data obtained were used for the daily monitoring of the radiation environment aboard the station. This paper considers the technique of RMS data analysis that allows one to distinguish the contributions of galactic cosmic rays and the Earth's inner radiation belt to the daily dose based on the dosimetry data obtained as a result of the station's passage in areas of the highest geomagnetic latitudes. The paper presents the results of an analysis of the dosimetry data based on this technique for 2005-2011, as well as a comparison with similar results the authors obtained previously using the technique based on an analysis of the dosimetry data obtained during station passages in the area of the South Atlantic Anomaly.

TeV Blazars and Cosmic Infrared Background Radiation

OpenAIRE

Aharonian, F. A.

2001-01-01

The recent developments in studies of TeV radiation from blazars are highlighted and the implications of these results for derivation of cosmologically important information about the cosmic infrared background radiation are discussed.

European Legalisation on Protection Against Cosmic Radiation

International Nuclear Information System (INIS)

Courades, M.

1999-01-01

Specific provisions on protection of aircrew against cosmic radiation have been laid down for the first time at EU level as part of the Basic Safety Standards for the Health Protection of the General Public and Workers against the Dangers of Ionizing Radiation (Council Directive 96/29/Euratom of 13 May 1996). These provisions, focusing mainly on health and radiological surveillance, are minimal requirements; therefore the Directive leaves significant discretion to the Member States as regards actions to be taken; Member States have to transpose these provisions into national law before 13 May 2000. Further harmonisation of Community regulations on civil aviation safety will be needed in the field of protection against cosmic radiation. This is to obtain a high level of radiation protection for the aircrew and to maintain fair competition under the common transport policy. Additionally, particular requirement are foreseen for detection and monitoring devices as well as for working instructions (Operations Manual). (author)

Cerenkov radiation from cosmic rays

International Nuclear Information System (INIS)

Turver, K.E.

1988-01-01

It is almost 40 years since it was suggested that Cerenkov radiations may be produced in the atmosphere by the passage of the cosmic radiation and account for a small part of the night sky brightness. The first detection of this visible Cerenkov radiation followed within a few years and by the 1960s the atmospheric Cerenkov radiation technique was established as a tool in high energy astrophysics. An exciting new field of astronomy, high energy gamma ray astronomy, has developed which relies on the atmospheric Cerenkov light. We here review the mechanism for the production of Cerenkov light in the atmosphere and summarize the contributions to high energy astrophysics made using the technique. (author)

Measurement of secondary cosmic radiation and calculation of associated dose conversion coefficients for humans; Messung sekundaerer kosmischer Strahlung und Berechnung der zugehoerigen Dosiskonversionskoeffizienten fuer den Menschen

Energy Technology Data Exchange (ETDEWEB)

Simmer, Gregor

2012-04-11

Due to secondary cosmic radiation (SCR), pilots and flight attendants receive elevated effective doses at flight altitudes. For this reason, since 2003 aircrew members are considered as occupationally exposed, in Germany. This work deals with the calculation of dose conversion coefficients (DCC) for protons, neutrons, electrons, positrons, photons and myons, which are crucial for estimation of effective dose from SCR. For the first time, calculations were performed combining Geant4 - a Monte Carlo code developed at CERN - with the voxel phantoms for the reference female and male published in 2008 by ICRP and ICRU. Furthermore, measurements of neutron fluence spectra - which contribute the major part to the effective dose of SCR - were carried out at the Environmental Research Station Schneefernerhaus (UFS) located at 2650 m above sea level nearby the Zugspitze mountain, Germany. These measured neutron spectra, and additionally available calculated spectra, were then folded with the DCC calculated in this work, and effective dose rates for different heights were calculated.

SIGMA/B, Doses in Space Vehicle for Multiple Trajectories, Various Radiation Source

International Nuclear Information System (INIS)

Jordan, T.M.

2003-01-01

1 - Description of problem or function: SIGMA/B calculates radiation dose at arbitrary points inside a space vehicle, taking into account vehicle geometry, heterogeneous placement of equipment and stores, vehicle materials, time-weighted astronaut positions and many radiation sources from mission trajectories, e.g. geomagnetically trapped protons and electrons, solar flare particles, galactic cosmic rays and their secondary radiations. The vehicle geometry, equipment and supplies, and man models are described by quadric surfaces. The irradiating flux field may be anisotropic. The code can be used to perform simultaneous dose calculations for multiple vehicle trajectories, each involving several radiation sources. Results are presented either as dose as a function of shield thickness, or the dose received through designated outer sections of the vehicle. 2 - Method of solution: Automatic sectoring of the vehicle is performed by a Simpson's rule integration over angle; the dose is computed by a numerical angular integration of the dose attenuation kernels about the dose points. The kernels are curve-fit functions constructed from input data tables. 3 - Restrictions on the complexity of the problem: The code uses variable dimensioning techniques to store data. The only restriction on problem size is the available core storage

Radiative hazard of solar flares in the nearterrestrial cosmic space

International Nuclear Information System (INIS)

Kolomenskij, A.V.; Petrov, V.M.; Zil', M.V.; Eremkina, T.M.

1978-01-01

Simulation of radiation enviroment due to solar cosmic rays was carried out in the near-terrestrial space. Systematized are the data on cosmic ray flux and spectra detected during 19-th and 20-th cycles of solar activity. 127 flares are considered with proton fluxes of more than 10 proton/cm 2 at energies higher than 30 MeV. Obtained are distribution functions of intervals between flares, flux distribution of flares and characteristic rigidity, and also distribution of magnetic disturbances over Dsub(st)-variation amplitude. The totality of these distributions presents the statistic model of radiation enviroment caused by solar flare protons for the period of maximum solar .activity. This model is intended for estimation of radiation hazard at manned cosmic flights

Pressurized ionization chamber dose ratemeter for enviromental radiation measaurement

Energy Technology Data Exchange (ETDEWEB)

Qingyu, Yue; Hua, Jin; Youling, Jiang

1986-01-01

The dose ratemeter, mainly used for measuring absorbed doserate of environmental gamma radiation and the charged particle components of cosmic-rays in /sup f/ree-air/sup ,/ consists of an energy compensated spherical pressurized ionization chamber, a MOS electrometer and a digital voltmeter. The flat energy response of the pressurized ionization chamber ranges from 60 keV to 1250 keV. It has good stability and higher sensitivity, and weights 6 kg.

Estimate on external effective doses received by the Iranian population from environmental gamma radiation sources

Energy Technology Data Exchange (ETDEWEB)

Roozitalab, J.; Reza deevband, M.; Rastkhah, N. [National Radiation Protection Dept. Atomic Energy Organization (Iran, Islamic Republic of); Sohrabi, M. [Intenatinal atomic Energy Agency, Vienna (Austria)

2006-07-01

Concentration of natural radioactive materials, especially available U 238, Ra 226, Th 232, and K 40 in construction materials and soil, as well as absorb dose from cosmic rays, is the most important source of the people for effective doses from the environment radiation. In order to evaluate external effective dose, it has been carried out more than 1000 measurements in 36 cities by sensitive dosimeters to environmental gamma radiation for indoor and outdoor conditions in residential areas; which its results show that range of gamma exposure for inside of buildings in Iran is 8.7-20.5 {mu}R/h, and outdoor environments of different cities is 7.9-20.6 {mu}R/h, which their mean value are 14.33 and 12.62 {mu}R/h respectively. Meanwhile, it has been estimated that beam-absorbing ratio between indoor and outdoor in measured environments is 1.55, except contribution of cosmic rays. This studies show that average effective dose for each Iranian person from environmental gamma is 96.9 n Sv/h, and annually effective dose for every person is 0.848 mSv. (authors)

Estimate on external effective doses received by the Iranian population from environmental gamma radiation sources

International Nuclear Information System (INIS)

Roozitalab, J.; Reza deevband, M.; Rastkhah, N.; Sohrabi, M.

2006-01-01

Concentration of natural radioactive materials, especially available U 238, Ra 226, Th 232, and K 40 in construction materials and soil, as well as absorb dose from cosmic rays, is the most important source of the people for effective doses from the environment radiation. In order to evaluate external effective dose, it has been carried out more than 1000 measurements in 36 cities by sensitive dosimeters to environmental gamma radiation for indoor and outdoor conditions in residential areas; which its results show that range of gamma exposure for inside of buildings in Iran is 8.7-20.5 μR/h, and outdoor environments of different cities is 7.9-20.6 μR/h, which their mean value are 14.33 and 12.62 μR/h respectively. Meanwhile, it has been estimated that beam-absorbing ratio between indoor and outdoor in measured environments is 1.55, except contribution of cosmic rays. This studies show that average effective dose for each Iranian person from environmental gamma is 96.9 n Sv/h, and annually effective dose for every person is 0.848 mSv. (authors)

Primary cosmic radiation

International Nuclear Information System (INIS)

Anderson, H.R.

1972-01-01

The term cosmic radiation means the charged particle flux that reaches the earth from outside its magnetosphere with energies above the solar wind energy of a few keV. There are two sources of flux. Sporadically the sun produces such particles, generally within the energy range 1--200 MeV, and these solar cosmic rays arrive at the earth for a period ranging from hours to days. There may be a small, rather constant flux from the sun also, but the bulk of the steady flux originates outside the earth's orbit. Although some have conjectured that part of this latter flux may be accelerated in the outer portions of the solar system where the outward flowing interplanetary medium meets the interstellar medium, it is generally thought that most or all of it arises in unique systems such as supernovae, and is distributed throughout the galaxy. These galactic particles range in energy from a few MeV to at least 10 13 MeV and consist primarily of protons with significant numbers of heavier nuclei, positrons and electrons. They are supposed to fill our galaxy, or at least the disc, more or less uniformly. However, the flux with energies below a few GeV that reaches earth's orbit is modulated by the interplanetary medium so that the number at earth varies inversely with solar activity and is always somewhat below the interstellar flux. A discussion is presented of primary galactic radiation at earth, its modulation by solar activity, and its interaction with the geomagnetic field. (U.S.)

Dosimetry for occupational exposure to cosmic radiation

International Nuclear Information System (INIS)

Bartlett, D.T.; McAulay, I.R.; Schrewe, U.J.

1997-01-01

Aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, aircraft structure, etc. This has been recognised for some time and estimates of the exposure of aircraft crew have been made previously and included in, for example, UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) publications. The recent increased interest has been brought about by several factors - the consideration that the relative biological effectiveness of the neutron component was being underestimated; the trend towards higher cruising altitudes for subsonic commercial aircraft and business jet aircraft; and most importantly, the recommendations of the International Commission on Radiological Protection (ICRP) in Publication 60, and the revision of the Euratom Basic Safety Standards Directive (BSS). In 1992, the European Dosimetry Group (EURADOS) established a Working Group to consider the exposure to cosmic radiation of aircraft crew, and the scientific and technical problems associated with radiation protection dosimetry for this occupational group. The Working Group was composed of fifteen scientists (plus a corresponding member) involved in this field of study and with knowledge of radiation measurement at aviation altitudes. This paper is based on the findings of this Working Group. (author)

Cosmic radiation and airline pilots: Exposure pattern as a function of aircraft type

International Nuclear Information System (INIS)

Tveten, U.; Haldorsen, T.; Reitan, J.

2000-01-01

The project presented here has been carried out as part of an epidemiological project on Norwegian aircraft personnel, entitled 'Exposure to low level ionising radiation and incidence of cancer in airline pilots and crew'. The purpose of the main project is to determine if there may be a relationship between exposure to cosmic radiation at aircraft cruising altitudes and the incidence of cancer. The methodology used as basis for estimating the radiation exposures is presented. The information used as basis for the dose estimations comes from a variety of sources: the files at the Personnel Licensing Section and the Aviation Medical Section of Norwegian Aviation Administration, the route tables of Scandinavian Airlines System (SAS), large amounts of expert information contributed by members of the Pilot's Associations in Norway and a couple of non-Norwegian pilots and from other members of the staff of SAS and other airlines. The estimation for each pilot was based on individual information of annual block hours and an estimated dose rate for each type of aircraft. The latter was estimated as a weighted average of CARI-estimated doses on a selection of routes flown by the airplanes in the different time periods. The project includes all pilots that have been licensed in Norway since 1946. These pilots have been flying a large variety of different types of aircraft and routes. The cosmic radiation intensity is a function of altitude in the atmosphere and, less markedly, of geographical latitude and of the intensity of the radiation from the sun (quantified as the heliocentric potential). Different types of aircraft fly at different altitudes and are used for different purposes (passenger traffic, cargo, air photography, preparation of maps etc) and used on different routes. The end results of the project described in this article are radiation exposures per block hour for each type of aircraft, and for each individual year (the differences between years reflect the

Prototype Operational Advances for Atmospheric Radiation Dose Rate Specification

Science.gov (United States)

Tobiska, W. K.; Bouwer, D.; Bailey, J. J.; Didkovsky, L. V.; Judge, K.; Garrett, H. B.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R. W.; Bell, D.; Mertens, C. J.; Xu, X.; Crowley, G.; Reynolds, A.; Azeem, I.; Wiltberger, M. J.; Wiley, S.; Bacon, S.; Teets, E.; Sim, A.; Dominik, L.

2014-12-01

Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. The coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has developed innovative, new space weather observations that will become part of the toolset that is transitioned into operational use. One prototype operational system for providing timely information about the effects of space weather is SET's Automated Radiation Measurements for Aerospace Safety (ARMAS) system. ARMAS will provide the "weather" of the radiation environment to improve aircraft crew and passenger safety. Through several dozen flights the ARMAS project has successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time via Iridium satellites, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. We are extending the dose measurement domain above commercial aviation altitudes into the stratosphere with a collaborative project organized by NASA's Armstrong Flight Research Center (AFRC) called Upper-atmospheric Space and Earth Weather eXperiment (USEWX). In USEWX we will be flying on the ER-2 high altitude aircraft a micro dosimeter for

Cosmic microwave background radiation of black hole universe

Science.gov (United States)

Zhang, T. X.

2010-11-01

Modifying slightly the big bang theory, the author has recently developed a new cosmological model called black hole universe. This new cosmological model is consistent with the Mach principle, Einsteinian general theory of relativity, and observations of the universe. The origin, structure, evolution, and expansion of the black hole universe have been presented in the recent sequence of American Astronomical Society (AAS) meetings and published recently in a scientific journal: Progress in Physics. This paper explains the observed 2.725 K cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present universe with hundred billion-trillions of solar masses. According to the black hole universe model, the observed cosmic microwave background radiation can be explained as the black body radiation of the black hole universe, which can be considered as an ideal black body. When a hot and dense star-like black hole accretes its ambient materials and merges with other black holes, it expands and cools down. A governing equation that expresses the possible thermal history of the black hole universe is derived from the Planck law of black body radiation and radiation energy conservation. The result obtained by solving the governing equation indicates that the radiation temperature of the present universe can be ˜2.725 K if the universe originated from a hot star-like black hole, and is therefore consistent with the observation of the cosmic microwave background radiation. A smaller or younger black hole universe usually cools down faster. The characteristics of the original star-like or supermassive black hole are not critical to the physical properties of the black hole universe at present, because matter and radiation are mainly from the outside space, i.e., the mother universe.

A pressurized ionization chamber dose ratemeter for enviromental radiation measaurement

International Nuclear Information System (INIS)

Yue Qingyu; Jin Hua

1986-01-01

The dose ratemeter, mainly used for measuring absorbed doserate of environmental gamma radiation and the charged particle components of cosmic-rays in f ree-air , consists of an energy compensated spherical pressurized ionization chamber, a MOS electrometer and a digital voltmeter. The flat energy response of the pressurized ionization chamber ranges from 60 keV to 1250 keV. It has good stability and higher sensitivity, and weights 6 kg

Cosmic radiation induced chromosomal aberrations in human lymphocytes

International Nuclear Information System (INIS)

De Angelis, G.; Facius, R.; Reitz, G.

2003-01-01

Since decades, elevated frequencies of dicentric chromosomes (DIC) in human lymphocytes have successfully been used as a biological dosimeter in cases of acute, often accidental exposures to ionizing radiation. As long as duration and time lags after exposure are small compared to the lifetime of DIC, their frequencies can also be used to assess doses from protracted, chronic irradiation. E.g., within the substantial range of uncertainties, the frequencies of DIC observed in cosmonauts are compatible with the frequencies expected from doses of low and high LET radiation to which they were exposed in low earth orbit (LEO). On the other hand, frequencies of DIC detected in lymphocytes of civilian aviation crewmembers rarely correlate with the doses accumulated all along their professional career. For such long duration exposures with relatively low induction rates, the concomitant decay of DIC frequencies due to the removal during exposure of lymphocytes carrying DIC has to be taken into account. We present temporal profiles of frequencies of DIC during the exposure calculated with a model of exponential decay of DIC for some scenarios of chronic exposure to cosmic radiation. E.g., even after a 'heavily' shielded Mars mission, the expected frequencies of DIC in lymphocytes of astronauts will be 10 to 40 times higher than the terrestrial control levels. For air flight personnel we calculated the time profiles of frequencies of DIC in lymphocytes of a 'typical' pilot, a male cabin attendant and a female cabin attendant whose professional radiation exposures were recalculated for the actual flight routes flown during their entire flight career as recorded in detailed duty logs. These results demonstrate that experimental (epidemiological) studies concerning DIC in air or space flight personnel must explicitly take into consideration the temporal exposure profiles in the prospective study population and that the point in time at which blood samples are to be drawn must

Measurements of the cosmic background radiation

International Nuclear Information System (INIS)

Weiss, R.

1980-01-01

Measurements of the attributes of the 2.7-K microwave background radiation (CBR) are reviewed, with emphasis on the analytic phase of CBR studies. Methods for the direct measurement of the CBR spectrum are discussed. Attention is given to receivers, antennas, absolute receiver calibration, atmospheric emission and absorption, the galactic background contribution, the analysis of LF measurements, and recent HF observations of the CBR spectrum. Measurements of the large-angular-scale intensity distribution of the CBR (the most convincing evidence that the radiation is of cosmological origin) are examined, along with limits on the linear polarization of the CBR. A description is given of the NASA-sponsored Cosmic Background Explorer (COBE) satellite mission. The results of the COBE mission will be a set of sky maps showing, in the wave number range from 1 to 10,000 kaysers, the galactic background radiation due to synchrotron emission from galactic cosmic rays, to diffuse thermal emission from H II regions, and to diffuse thermal emission from interstellar and interplanetary dust, as well as a residue consisting of the CBR and whatever other cosmological background might exist

Occupational cosmic radiation exposure in Portuguese airline pilots: study of a possible correlation with oxidative biological markers.

Science.gov (United States)

Silva, Rodrigo; Folgosa, Filipe; Soares, Paulo; Pereira, Alice S; Garcia, Raquel; Gestal-Otero, Juan Jesus; Tavares, Pedro; Gomes da Silva, Marco D R

2013-05-01

Several studies have sought to understand the health effects of occupational exposure to cosmic radiation. However, only few biologic markers or associations with disease outcomes have so far been identified. In the present study, 22 long- and 26 medium-haul male Portuguese airline pilots and 36 factory workers who did not fly regularly were investigated. The two groups were comparable in age and diet, were non-smokers, never treated with ionizing radiation and other factors. Cosmic radiation exposure in pilots was quantified based on direct monitoring of 51 flights within Europe, and from Europe to North and South America, and to Africa. Indirect dose estimates in pilots were performed based on the SIEVERT (Système informatisé d'évaluation par vol de l'exposition au rayonnement cosmique dans les transports aériens) software for 6,039 medium- and 1,366 long-haul flights. Medium-haul pilots had a higher cosmic radiation dose rate than long-haul pilots, that is, 3.3 ± 0.2 μSv/h and 2.7 ± 0.3 μSv/h, respectively. Biological tests for oxidative stress on blood and urine, as appropriate, at two time periods separated by 1 year, included measurements of antioxidant capacity, total protein, ferritin, hemoglobin, creatinine and 8-hydroxy-2-deoxyguanosine (8OHdG). Principal components analysis was used to discriminate between the exposed and unexposed groups based on all the biological tests. According to this analysis, creatinine and 8OHdG levels were different for the pilots and the unexposed group, but no distinctions could be made among the medium- and the long-haul pilots. While hemoglobin levels seem to be comparable between the studied groups, they were directly correlated with ferritin values, which were lower for the airline pilots.

Health Effects of Exposure to Low Dose of Radiation

International Nuclear Information System (INIS)

Alatas, Zubaidah

2003-01-01

Human beings are exposed to natural radiation from external sources include radionuclides in the earth and cosmic radiation, and by internal radiation from radionuclides, mainly uranium and thorium series, incorporated into the body. Living systems have adapted to the natural levels of radiation and radioactivity. But some industrial practices involving natural resources enhance these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Biological effects of ionizing radiation are the outcomes of physical and chemical processes that occur immediately after the exposure, then followed by biological process in the body. These processes will involve successive changes in the molecular, cellular, tissue and whole organism levels. Any dose of radiation, no matter how small, may produce health effects since even a single ionizing event can result in DNA damage. The damage to DNA in the nucleus is considered to be the main initiating event by which radiation causes damage to cells that results in the development of cancer and hereditary disease. It has also been indicated that cytogenetic damage can occur in cells that receive no direct radiation exposure, known as bystander effects. This paper reviews health risks of low dose radiation exposure to human body causing stochastic effects, i.e. cancer induction in somatic cells and hereditary disease in genetic cells. (author)

Measurements of Background Gamma Radiation on Some Localities of North-East Kosovo

OpenAIRE

, G. Hodolli; , Y. Halimi; , R. Gashi; , Se. Kadiri; , B. Xhafa; , A. Jonuzaj

2016-01-01

The measurement of natural environmental radiations is one of the most important subjects in health physics. The main sources of background radiation are cosmic, terrestrial and cosmogenic radiation produced by reactions with cosmic rays and atmospheric nuclei. Terrestrial radiation varies in different regions in the world. Generally the background dose rate from cosmic rays depends on the latitude and altitude. The dose rate range obtained in some northeast Kosovo, the dose rate varies from ...

Level of natural background radiation and dose to population in Jilin Province

International Nuclear Information System (INIS)

Li Wanxi; Chen Huiying; Ju Cuixiang; Li Fulin; Li Xianggao

1994-01-01

The natural background radiation in Jilin Province was measured and the population dose was estimated. The results showed that the population-weighted average value of the absorbed dose rate in air from cosmic ray ionization was 3.2 x 10 -8 Gy·h -1 . The average absorbed dose rates in air from terrestrial γ radiation were 7.7 x 10 -8 Gy·h -1 outdoors and 9.8 x 10 -8 Gy·h -1 indoors. The average values of radon in air were 8.7 Bq·m -3 outdoors and 5.8 Bq·m -3 indoors. The average concentration of natural radionuclides U, Th, 226 Ra, and 40 K were 3.7 x 10 -2 , 2.4 x 10 -2 , 14.7 x 10 -2 and 81.5 Bq·kg -1 in food, and 2.3, 0.1, 1.1 and 0.3 Bq·L -1 in drinking water, respectively. The total annual individual average effective dose equivalent from natural background radiation was about 1.5 mSv

Environmental policy. Ambient radioactivity levels and radiation doses in 1998

International Nuclear Information System (INIS)

1999-11-01

The report contains information on the natural (background) radiation exposure (chapter II), the natural radiation exposure as influenced by anthropogenic effects (chapter III), the anthropogenic radiation exposure (chapter IV), and the radiation doses to the environment and the population emanating from the Chernobyl fallout (chapter V). The natural radiation exposure is specified referring to the contributions from cosmic and terrestrial background radiation and intake of natural radioactive substances. Changes of the natural environment resulting from anthropogenic effects (technology applications) inducing an increase in concentration of natural radioactive substances accordingly increase the anthropogenic radiation exposure. Indoor air radon concentration in buildings for instance is one typical example of anthropogenic increase of concentration of natural radioactivity, primarily caused by the mining industry or by various materials processing activities, which may cause an increase in the average radiation dose to the population. Measurements so far show that indoor air concentration of radon exceeds a level of 200 Bq/m 3 in less than 2% of the residential buildings; the EUropean Commission therefore recommends to use this concentration value as a maximum value for new residential buildings. Higher concentrations are primarily measured in areas with relevant geological conditions and abundance of radon, or eg. in mining areas. (orig./CB) [de

The cosmic microwave background radiation

International Nuclear Information System (INIS)

Wilson, R.W.

1980-01-01

The history is described of the discovery of microwave radiation of the cosmic background using the 20-foot horn antenna at the Bell Laboratories back in 1965. Ruby masers with travelling wave were used, featuring the lowest noise in the world. The measurement proceeded on 7 cm. In measuring microwave radiation from the regions outside the Milky Way continuous noise was discovered whose temperature exceeded the calculated contributions of the individual detection system elements by 3 K. A comparison with the theory showed that relict radiation from the Big Bang period was the source of the noise. The discovery was verified by measurements on the 20.1 cm wavelength and by other authors' measurements on 0.5 mm to 74 cm, and by optical measurements of the interstellar molecule spectrum. (Ha)

NAIRAS aircraft radiation model development, dose climatology, and initial validation.

Science.gov (United States)

Mertens, Christopher J; Meier, Matthias M; Brown, Steven; Norman, Ryan B; Xu, Xiaojing

2013-10-01

[1] The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a real-time, global, physics-based model used to assess radiation exposure to commercial aircrews and passengers. The model is a free-running physics-based model in the sense that there are no adjustment factors applied to nudge the model into agreement with measurements. The model predicts dosimetric quantities in the atmosphere from both galactic cosmic rays (GCR) and solar energetic particles, including the response of the geomagnetic field to interplanetary dynamical processes and its subsequent influence on atmospheric dose. The focus of this paper is on atmospheric GCR exposure during geomagnetically quiet conditions, with three main objectives. First, provide detailed descriptions of the NAIRAS GCR transport and dosimetry methodologies. Second, present a climatology of effective dose and ambient dose equivalent rates at typical commercial airline altitudes representative of solar cycle maximum and solar cycle minimum conditions and spanning the full range of geomagnetic cutoff rigidities. Third, conduct an initial validation of the NAIRAS model by comparing predictions of ambient dose equivalent rates with tabulated reference measurement data and recent aircraft radiation measurements taken in 2008 during the minimum between solar cycle 23 and solar cycle 24. By applying the criterion of the International Commission on Radiation Units and Measurements (ICRU) on acceptable levels of aircraft radiation dose uncertainty for ambient dose equivalent greater than or equal to an annual dose of 1 mSv, the NAIRAS model is within 25% of the measured data, which fall within the ICRU acceptable uncertainty limit of 30%. The NAIRAS model predictions of ambient dose equivalent rate are generally within 50% of the measured data for any single-point comparison. The largest differences occur at low latitudes and high cutoffs, where the radiation dose level is low. Nevertheless, analysis

NAIRAS aircraft radiation model development, dose climatology, and initial validation

Science.gov (United States)

Mertens, Christopher J.; Meier, Matthias M.; Brown, Steven; Norman, Ryan B.; Xu, Xiaojing

2013-10-01

The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a real-time, global, physics-based model used to assess radiation exposure to commercial aircrews and passengers. The model is a free-running physics-based model in the sense that there are no adjustment factors applied to nudge the model into agreement with measurements. The model predicts dosimetric quantities in the atmosphere from both galactic cosmic rays (GCR) and solar energetic particles, including the response of the geomagnetic field to interplanetary dynamical processes and its subsequent influence on atmospheric dose. The focus of this paper is on atmospheric GCR exposure during geomagnetically quiet conditions, with three main objectives. First, provide detailed descriptions of the NAIRAS GCR transport and dosimetry methodologies. Second, present a climatology of effective dose and ambient dose equivalent rates at typical commercial airline altitudes representative of solar cycle maximum and solar cycle minimum conditions and spanning the full range of geomagnetic cutoff rigidities. Third, conduct an initial validation of the NAIRAS model by comparing predictions of ambient dose equivalent rates with tabulated reference measurement data and recent aircraft radiation measurements taken in 2008 during the minimum between solar cycle 23 and solar cycle 24. By applying the criterion of the International Commission on Radiation Units and Measurements (ICRU) on acceptable levels of aircraft radiation dose uncertainty for ambient dose equivalent greater than or equal to an annual dose of 1 mSv, the NAIRAS model is within 25% of the measured data, which fall within the ICRU acceptable uncertainty limit of 30%. The NAIRAS model predictions of ambient dose equivalent rate are generally within 50% of the measured data for any single-point comparison. The largest differences occur at low latitudes and high cutoffs, where the radiation dose level is low. Nevertheless, analysis suggests

Cosmic ray exposure in aircraft and space flight

International Nuclear Information System (INIS)

Kosako, Toshiso; Sugiura, Nobuyuki; Iimoto, Takeshi

2000-01-01

The exposure from cosmic ray radiation to the workers and public is a new aspect of exposure that was cased by the development of science and technology. ICRP Publication 60 says: 'to provide some practical guidance, the Commission recommends that there should be a requirement to include exposure to natural sources as part of occupational exposure only in the following cases: radon..., some natural radionuclides..., operation of jet air craft, space flight'. For this situation what kind of radiation protection concept is applicable? And what kind of radiation guideline and procedure are possible to propose? Here, we would like to review the past activities on this issue and to summarize the concepts in ICRP concerning to these exposure. Then the recommended radiation protection system will be proposed as one trial to this solution. In the paper the characters of cosmic ray were firstly reviewed. Cosmic rays are consisted by solar one and galactic one. Both of them have high energy and this will cause the difficulty of dosimetry because of lacking of physical and biological data. Next discussion point is a classification of exposure. For this, several classifications were done: jet airplane flight, supersonic airplane flight and space flight. Other classification is aircrew (occupational exposure), passengers (public exposure), frequent flyers (gray zone), space astronauts (special mission), and pregnant women. Considering the real level of radiation the practical radiation control is proposed including the cosmic radiation exposure prediction method by computer codes. The discussion of space astronauts is a little different for the highness of radiation doses. The dose levels will be obtained through the discussion of lifetime risk balancing their mission importance. (author)

Low earth orbit radiation dose distribution in a phantom head

International Nuclear Information System (INIS)

Konradi, A.; Badhwar, G.D.; Cash, B.L.; Hardy, K.A.

1992-01-01

In order to compare analytical methods with data obtained during exposure to space radiation, a phantom head instrumented with a large number of radiation detectors was flown on the Space Shuttle on three occasions: 8 August 1989 (STS-28), 28 February 1990 (STS-36), and 24 April 1990 (STS-31). The objective of this experiment was to obtain a measurement of the inhomogeneity in the dose distribution within a phantom head volume. The orbits of these missions were complementary-STS-28 and STS-36 had high inclination and low altitude, while STS-31 had a low inclination and high altitude. In the cases of STS-28 and STS-36, the main contribution to the radiation dose comes from galactic cosmic rays (GCR) with a minor to negligible part supplied by the inner belt through the South Atlantic Anomaly (SAA), and for STS-28 an even smaller one from a proton enhancement during a solar flare-associated proton event. For STS-31, the inner belt protons dominate and the GCR contribution is almost negligible. The internal dose distribution is consistent with the mass distribution of the orbiter and the self-shielding and physical location of the phantom head. (author)

Cosmic rays in space

International Nuclear Information System (INIS)

Fujitaka, Kazunobu

2005-01-01

Cosmos is a mysterious space by which many researchers are fascinated for many years. But, going into space means that we will receive extra exposure due to existence of cosmic rays. Cosmic rays are mainly composed of highly energetic protons. It was born in the last stage of stellar life. Understanding of cosmos will certainly bring right understanding of radiation energy, or energy itself. As no one could see the very early stage of cosmic rays, there is only a speculation. But it is better to speculate something based on certain side evidences, than to give up the whole. Such attitude shall be welcomed in the space researches. Anyway, cosmic rays were born in the last explosion of a star, which is called as Super Nova. After cosmic rays are emitted from the Super Nova, it will reach to the human surroundings. To indicate its intensity, special unit of ''dose rate'' is used. When a man climbs a mountain, cosmic ray intensity surely increases. It doubles as he goes up every 1500m elevation. It was ascertained by our own measurements. Then what happens when the goes up more? At aviation altitude, where airplanes fly, the dose rate will be increased up to 100times the high mountain cases. And what is expected when he goes up further more, up to space orbit altitude? In this case, the dose rate increases up to 10times the airplane cases. Geomagnetism affects the dose rate very much. As primary cosmic ray particles are charged particles, they cannot do well with existence of the magnetic field. In effect, cosmic rays can penetrate into the polar atmosphere along geomagnetic lines of forces which stand almost vertical, but penetration of low energy cosmic rays will be banned when they intend to penetrate crossing the geomagnetic lines of forces in equatorial region. Therefore, exposure due to cosmic rays will become large in polar region, while it remains small in equatorial region. In effect, airplanes which fly over the equator. Only, we have to know that the cosmos

PROTECTION FROM COSMIC RADIATION IN LONG-TERM MANNED SPACEFLIGHTS

Directory of Open Access Journals (Sweden)

Marco Durante

2012-06-01

Full Text Available Current space programs are shifting toward planetary exploration, and in particular towards human missions to the moon and Mars. Space radiation, comprised of energetic protons and heavy nuclei, has been shown to produce distinct biological damage compared to radiation on Earth, leading to large uncertainties in the projection of health risks. Even if uncertainties in risk assessment will be reduced in the next few years, there is little doubt that appropriate countermeasures have to be taken to reduce the exposure or the biological damage produced by cosmic radiation. In addition, it is necessary to provide effective countermeasures against solar particle events, which can produce acute effects, even life threatening, for inadequately protected crews. Unfortunately, passive (bulk shielding is currently unable to provide adequate protection, because cosmic rays have very high energy and nuclear fragmentation in the absorbers produce light fragments. Material science could provide new materials with better shielding properties for space radiation. Active (magnetic shielding could be an interesting alternative, pending technical improvements.

The anisotropy of the cosmic background radiation from local dynamic density perturbations

International Nuclear Information System (INIS)

Dyer, C.C.; Ip, P.S.S.

1988-01-01

Contrary to the usual assumption, it is shown here that the anisotropy of the cosmic background radiation need not be dominated by perturbations at the last scattering surface. The results of computer simulations are shown in which local dynamic density perturbations, in the form of Swiss cheese holes with finite, uniform density central lumps, are the main source of anisotropy of the cosmic background radiation. (author)

Cosmic rays and terrestrial life: A brief review

Science.gov (United States)

Atri, Dimitra; Melott, Adrian L.

2014-01-01

“The investigation into the possible effects of cosmic rays on living organisms will also offer great interest.” - Victor F. Hess, Nobel Lecture, December 12, 1936 High-energy radiation bursts are commonplace in our Universe. From nearby solar flares to distant gamma ray bursts, a variety of physical processes accelerate charged particles to a wide range of energies, which subsequently reach the Earth. Such particles contribute to a number of physical processes occurring in the Earth system. A large fraction of the energy of charged particles gets deposited in the atmosphere, ionizing it, causing changes in its chemistry and affecting the global electric circuit. Remaining secondary particles contribute to the background dose of cosmic rays on the surface and parts of the subsurface region. Life has evolved over the past ∼3 billion years in presence of this background radiation, which itself has varied considerably during the period [1-3]. As demonstrated by the Miller-Urey experiment, lightning plays a very important role in the formation of complex organic molecules, which are the building blocks of more complex structures forming life. There is growing evidence of increase in the lightning rate with increasing flux of charged particles. Is there a connection between enhanced rate of cosmic rays and the origin of life? Cosmic ray secondaries are also known to damage DNA and cause mutations, leading to cancer and other diseases. It is now possible to compute radiation doses from secondary particles, in particular muons and neutrons. Have the variations in cosmic ray flux affected the evolution of life on earth? We describe the mechanisms of cosmic rays affecting terrestrial life and review the potential implications of the variation of high-energy astrophysical radiation on the history of life on earth.

Sequential measurements of spectrum and dose for cosmic-ray neutrons on the ground

International Nuclear Information System (INIS)

Hirabayashi, N.; Nunomiya, T.; Suzuki, H.; Nakamura, T.

2002-01-01

The earth is continually bathed in high-energy particles that come from outside the solar system, known as galactic cosmic rays. When these particles penetrate the magnetic fields of the solar system and the Earth and reach the Earth's atmosphere, they collide with atomic nuclei in air and secondary cosmic rays of every kind. On the other hand, levels of accumulation of the semiconductor increase recently, and the soft error that the cosmic-ray neutrons cause has been regarded as questionable. There have been long-term measurements of cosmic-ray neutron fluence at several places in the world, but no systematic study on cosmic-ray neutron spectrum measurements. This study aimed to measure the cosmic-ray neutron spectrum and dose on the ground during the solar maximum period of 2000 to 2002. Measurements have been continuing in a cabin of Tohoku University Kawauchi campus, by using five multi-moderator spectrometers (Bonner sphere), 12.7 cm diam by 12.7 cm long NE213 scintillator, and rem counter. The Bonner sphere uses a 5.08 cm diam spherical 3 He gas proportional counter and the rem counter uses a 12.7 cm diam 3 He gas counter. The neutron spectra were obtained by unfolding from the count rates measured with the Bonner sphere using the SAND code and the pulse height spectra measured with the NE213 scintillator using the FORIST code . The cosmic- ray neutron spectrum and ambient dose rates have been measured sequentially from April 2001. Furthermore, the correlation between ambient dose rate and the atmospheric pressure was investigated with a barometer. We are also very much interested in the variation of neutron spectrum following big solar flares. From the sequential measurements, we found that the cosmic-ray neutron spectrum has two peaks at around 1 MeV and at around 100 MeV, and the higher energy peak increases with a big solar flare

Cosmic rays and radiations from the cosmos; Rayons cosmiques et rayonnement du cosmos

Energy Technology Data Exchange (ETDEWEB)

Parizot, E

2005-12-01

This document gathers a lot of recent information concerning cosmic radiations, it is divided into 4 parts. Part I: energy, mass and angular spectra of cosmic rays. Part II: general phenomenology of cosmic rays, this part deals with the standard model, the maximal energy of protons inside supernova remnants, nucleosynthesis of light elements, and super-bubbles. Part III: radiations from the cosmos, this part deals with high energy gamma rays, non-thermal radiation of super-bubbles, positron transport, and the Compton trail of gamma-ray bursts. Part IV: the Pierre Auger observatory (OPA), this part deals with the detection of gamma ray bursts at OPA, the measurement of anisotropy, and top-down models. (A.C.)

In-flight dose estimates for aircraft crew and pregnant female crew members in military transport missions

International Nuclear Information System (INIS)

Alves, J. G.; Mairos, J. C.

2007-01-01

Aircraft fighter pilots may experience risks other than the exposure to cosmic radiation due to the characteristics of a typical fighter flight. The combined risks for fighter pilots due to the G-forces, hypobaric hypoxia, cosmic radiation exposure, etc. have determined that pregnant female pilots should remain on ground. However, several military transport missions can be considered an ordinary civil aircraft flight and the question arises whether a pregnant female crew member could still be part of the aircraft crew. The cosmic radiation dose received was estimated for transport missions carried out on the Hercules C-130 type of aircraft by a single air squad in 1 month. The flights departed from Lisboa to areas such as: the Azores, several countries in central and southern Africa, the eastern coast of the USA and the Balkans, and an estimate of the cosmic radiation dose received on each flight was carried out. A monthly average cosmic radiation dose to the aircraft crew was determined and the dose values obtained were discussed in relation to the limits established by the European Union Council Directive 96/29/Euratom. The cosmic radiation dose estimates were performed using the EPCARD v3.2 and the CARI-6 computing codes. EPCARD v3.2 was kindly made available by GSF-National Research Centre for Environment and Health, Inst. of Radiation Protection (Neuherberg (Germany)). CARI-6 (version July 7, 2004) was downloaded from the web site of the Civil Aerospace Medical Inst., Federal Aviation Administration (USA). In this study an estimate of the cosmic radiation dose received by military aircraft crew on typical transport missions is made. (authors)

Cosmic radiation and airline pilots: Exposure pattern as a function of aircraft type

Energy Technology Data Exchange (ETDEWEB)

Tveten, U.; Haldorsen, T.; Reitan, J

2000-07-01

The project presented here has been carried out as part of an epidemiological project on Norwegian aircraft personnel, entitled 'Exposure to low level ionising radiation and incidence of cancer in airline pilots and crew'. The purpose of the main project is to determine if there may be a relationship between exposure to cosmic radiation at aircraft cruising altitudes and the incidence of cancer. The methodology used as basis for estimating the radiation exposures is presented. The information used as basis for the dose estimations comes from a variety of sources: the files at the Personnel Licensing Section and the Aviation Medical Section of Norwegian Aviation Administration, the route tables of Scandinavian Airlines System (SAS), large amounts of expert information contributed by members of the Pilot's Associations in Norway and a couple of non-Norwegian pilots and from other members of the staff of SAS and other airlines. The estimation for each pilot was based on individual information of annual block hours and an estimated doserate for each type of aircraft. The latter was estimated as a weighted average of CARI-estimated doses on a selection of routes flown by the airplanes in the different time periods. The project includes all pilots that have been licensed in Norway since 1946. These pilots have been flying a large variety of different types of aircraft and routes. The cosmic radiation intensity is a function of altitude in the atmosphere and, less markedly, of geographical latitude and of the intensity of the radiation from the sun (quantified as the heliocentric potential). Different types of aircraft fly at different altitudes and are used for different purposes (passenger traffic, cargo, air photography, preparation of maps etc) and used on different routes. The end results of the project described in this article are radiation exposures per block hour for each type of aircraft, and for each individual year (the differences between years

Collapse of radiating fluid spheres and cosmic censorship

International Nuclear Information System (INIS)

Unruh, W.G.

1985-01-01

The radiating-fluid-sphere model studied by Lake and Hellaby is reanalyzed to show that flat spacetime is a valid C 1 extension to their model and thus it does not force a violation of strong cosmic censorship

Noncommutative black-body radiation: Implications on cosmic microwave background

International Nuclear Information System (INIS)

Fatollahi, A.H.; Hajirahimi, M.

2006-01-01

Including loop corrections, black-body radiation in noncommutative space is anisotropic. A direct implication of possible space non-commutativity on the cosmic microwave background map is argued. (authors)

Diffuse Cosmic Infrared Background Radiation

Science.gov (United States)

Dwek, Eli

2002-01-01

The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

Focusing of cosmic radiation near power lines. A theoretical approach

International Nuclear Information System (INIS)

Skedsmo, A.; Vistnes, A.I.

1997-02-01

The purpose of this work was to determine if, and to what extent, cosmic radiation can be focused by power lines. As an alternative to experimental measurements, a computer program was developed for simulation of particle trajectories. Starting from given initial values, the cosmic particles trajectories through the electromagnetic field surrounding power lines were simulated. Particular efforts have been made to choose initial values which represent the actual physical condition of the cosmic radiation at ground level. The results show an average decrease in the particle flux density in an area below a power line and a corresponding increased flux between 12 m and 45 m on either side of the centre of the power line. The average shift in flux density is, however, extremely small (less than 0.1%) and probably not measurable with existing detector technology. 11 refs., 4 figs., 2 tabs

The estimation of the dose from cosmic radiation received by the population living at mainland areas of China

International Nuclear Information System (INIS)

Jin Hua; Yue Qingyu

1989-01-01

According to the distribution of cosmic ray ionization with altitude and latitude as well as the census information in all of our country (the end of the year 1986), the population-weighted mean annual effective dose equivalent received by the population living at mainland areas of China is estimated to be about 278 μSv, in which the ionizing component and the neutron component are 252 μSv and 26 μSv, respectively

Cosmic Dark Radiation and Neutrinos

Directory of Open Access Journals (Sweden)

Maria Archidiacono

2013-01-01

Full Text Available New measurements of the cosmic microwave background (CMB by the Planck mission have greatly increased our knowledge about the universe. Dark radiation, a weakly interacting component of radiation, is one of the important ingredients in our cosmological model which is testable by Planck and other observational probes. At the moment, the possible existence of dark radiation is an unsolved question. For instance, the discrepancy between the value of the Hubble constant, H0, inferred from the Planck data and local measurements of H0 can to some extent be alleviated by enlarging the minimal ΛCDM model to include additional relativistic degrees of freedom. From a fundamental physics point of view, dark radiation is no less interesting. Indeed, it could well be one of the most accessible windows to physics beyond the standard model, for example, sterile neutrinos. Here, we review the most recent cosmological results including a complete investigation of the dark radiation sector in order to provide an overview of models that are still compatible with new cosmological observations. Furthermore, we update the cosmological constraints on neutrino physics and dark radiation properties focusing on tensions between data sets and degeneracies among parameters that can degrade our information or mimic the existence of extra species.

RESPONSE OF THE GREEK EARLY WARNING SYSTEM REUTER-STOKES IONIZATION CHAMBERS TO TERRESTRIAL AND COSMIC RADIATION EVALUATED IN COMPARISON WITH SPECTROSCOPIC DATA AND TIME SERIES ANALYSIS.

Science.gov (United States)

Leontaris, F; Clouvas, A; Xanthos, S; Maltezos, A; Potiriadis, C; Kiriakopoulos, E; Guilhot, J

2018-02-01

The Telemetric Early Warning System Network of the Greek Atomic Energy Commission consists mainly of a network of 24 Reuter-Stokes high-pressure ionization chambers (HPIC) for gamma dose rate measurements and covers all Greece. In the present work, the response of the Reuter-Stokes HPIC to terrestrial and cosmic radiation was evaluated in comparison with spectroscopic data obtained by in situ gamma spectrometry measurements with portable hyper pure Germanium detectors (HPGe), near the Reuter-Stokes detectors and time series analysis. For the HPIC detectors, a conversion factor for the measured absorbed dose rate in air (in nGy h-1) to the total ambient dose equivalent rate Ḣ*(10), due to terrestrial and cosmic component, was deduced by the field measurements. Time series analysis of the mean monthly dose rate (measured by the Reuter-Stokes detector in Thessaloniki, northern Greece, from 2001 to 2016) was performed with advanced statistical methods (Fast Fourier Analysis and Zhao Atlas Marks Transform). Fourier analysis reveals several periodicities (periodogram). The periodogram of the absorbed dose rate in air values was compared with the periodogram of the values measured for the same period (2001-16) and in the same location with a NaI (Tl) detector which in principle is not sensitive to cosmic radiation. The obtained results are presented and discussed. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effective Dose Equivalent To The Cypriot Population Due To Natural Radiation

Energy Technology Data Exchange (ETDEWEB)

Christofides, S [Medical Physics Department, Nicosia General Hospital (Cyprus)

1994-12-31

A study was initiated by the Biomedical Research Foundation, two years ago, to estimate the various natural radiation components that contribute to the Effective Dose Equivalent (EDE) to the Cypriot population. The present study has shown that the contribution due to cosmic radiation is estimated to be less than 270 microSiverts per annum, while that due to airborne Rn-222 concentration in Cypriot houses is estimated to be less then 330 microSieverts per annum. The contribution due to terrestrial gamma radiations, which is currently under investigation, is so far estimated to be around 108 microSieverts per annum. Therefore the EDE to the Cypriot population due to natural radiation is likely to be around 700 microSieverts per annum, not taking into account the internal exposure due to other naturally occuring radionuclides. (author). 7 refs, 4 figs, 4 tabs.

Simulating cosmic radiation absorption and secondary particle production of solar panel layers of Low Earth Orbit (LEO) satellite with GEANT4

Science.gov (United States)

Yiǧitoǧlu, Merve; Veske, Doǧa; Nilüfer Öztürk, Zeynep; Bilge Demirköz, Melahat

2016-07-01

All devices which operate in space are exposed to cosmic rays during their operation. The resulting radiation may cause fatal damages in the solid structure of devices and the amount of absorbed radiation dose and secondary particle production for each component should be calculated carefully before the production. Solar panels are semiconductor solid state devices and are very sensitive to radiation. Even a short term power cut-off may yield a total failure of the satellite. Even little doses of radiation can change the characteristics of solar cells. This deviation can be caused by rarer high energetic particles as well as the total ionizing dose from the abundant low energy particles. In this study, solar panels planned for a specific LEO satellite, IMECE, are analyzed layer by layer. The Space Environment Information System (SPENVIS) database and GEANT4 simulation software are used to simulate the layers of the panels. The results obtained from the simulation will be taken in account to determine the amount of radiation protection and resistance needed for the panels or to revise the design of the panels.

Air crew exposure to cosmic radiation. New analysis, recommendations EURADOS

Energy Technology Data Exchange (ETDEWEB)

Spurny, F; Votockova, I [Academy of the Sciences of Czech Republic, Prague (Czech Republic). Nuclear Physics Institute, Department of Radiation Dosimetry

1996-12-31

Cosmic radiation on the board of an aircraft consist of two components: directly ionizing radiation (electron, proton - low LET) and neutrons (high LET). Neither composition nor the energy spectrum of usual on-Earth calibration sources ({sup 60}Co, {sup 252}Cf) do not correspond to the field on a board. Therefore high energy reference fields behind shielding high energy accelerator at CERN and Dubna have been created and intensively studied. Their typical characteristics following from the results of our measurements were obtained. In-flight measurements on the board of commercial aircraft have been realized since 1991 during about 20 flights, Flight routes extended from the 1.3 grad N up to about 65 grad N, flying altitudes varied from 8.2 km to 12.5 km. The exposure level due to galactic cosmic radiation is inversely proportional to the solar activity. Some radiation protection aspects were concluded: (a) The usual limits of annual air crew flight hours correspond at 11.3 km to about 4 mSv per year, with new ICRP conversion factors to about 5 mSv per year; (b) Monthly flight hours limit does not exclude that the exposure of a pregnant women can exceed 1 mSv during this period; (c) The air crew exposure should therefore be checked, controlled a nd administered as conscientiously as for any other group of occupationally exposed persons. A Working group 11 of EURADOS `Exposure of air crew to cosmic radiation` has been formed (1992-1995) to prepare basic analysis and recommendations concerning the topics. (Abstract Truncated)

Low dose radiation and plant growth

International Nuclear Information System (INIS)

Kim, Sung Jae; Lee, Hae Youn; Park, Hong Sook

2001-03-01

Ionizing radiation includes cosmic radiation, earth radiation, radionuclides for the medical purpose and nuclear industry, fallout radiation. From the experimental results of various radiation effects on seeds or seedlings, it was found that germination rate, development, respiration rate, reproduction and blooming were accelerated compared with the control. In mammal, hormesis phenomenon manifested itself in increased disease resistance, lifespan, and decreased rate of tumor incidence. In plants, it was shown that germination, sprouting, growth, development, blooming and resistance to disease were accelerated

Low dose radiation and plant growth

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Jae; Lee, Hae Youn; Park, Hong Sook

2001-03-01

Ionizing radiation includes cosmic radiation, earth radiation, radionuclides for the medical purpose and nuclear industry, fallout radiation. From the experimental results of various radiation effects on seeds or seedlings, it was found that germination rate, development, respiration rate, reproduction and blooming were accelerated compared with the control. In mammal, hormesis phenomenon manifested itself in increased disease resistance, lifespan, and decreased rate of tumor incidence. In plants, it was shown that germination, sprouting, growth, development, blooming and resistance to disease were accelerated.

Designing Spacecraft and Mission Operations Plans to Meet Flight Crew Radiation Dose Requirements: Why is this an "Epic Challenge" for Long-Term Manned Interplanetary Flight

Science.gov (United States)

Koontz, Steven

2012-01-01

Outline of presentation: (1) Radiation Shielding Concepts and Performance - Galactic Cosmic Rays (GCRs) (1a) Some general considerations (1b) Galactic Cosmic Rays (2)GCR Shielding I: What material should I use and how much do I need? (2a) GCR shielding materials design and verification (2b) Spacecraft materials point dose cosmic ray shielding performance - hydrogen content and atomic number (2c) Accelerator point dose materials testing (2d) Material ranking and selection guidelines (2e) Development directions and return on investment (point dose metric) (2f) Secondary particle showers in the human body (2f-1) limited return of investment for low-Z, high-hydrogen content materials (3) GCR shielding II: How much will it cost? (3a) Spacecraft design and verification for mission radiation dose to the crew (3b) Habitat volume, shielding areal density, total weight, and launch cost for two habitat volumes (3c) It's All about the Money - Historical NASA budgets and budget limits (4) So, what can I do about all this? (4a) Program Design Architecture Trade Space (4b) The Vehicle Design Trade Space (4c) Some Near Term Recommendations

Measurements of K/Π ratio in cosmic radiation

International Nuclear Information System (INIS)

Mahon, J.R.P.

1986-01-01

Measurements of k/Π ratio in cosmic radiation by its half lives and its fluxes, were carried out. The kaon flux was obtained using the Cherenkov detector, and for pion flux scintillation detectors were used. The final results of K/Π ratio ∼ 0.2 was obtained. (M.C.K.) [pt

Cosmic radiation and mortality from cancer among male German airline pilots: extended cohort follow-up

International Nuclear Information System (INIS)

Hammer, Gaël Paul; Blettner, Maria; Langner, Ingo; Zeeb, Hajo

2012-01-01

Commercial airline pilots are exposed to cosmic radiation and other specific occupational factors, potentially leading to increased cancer mortality. This was analysed in a cohort of 6,000 German cockpit crew members. A mortality follow-up for the years 1960–2004 was performed and occupational and dosimetry data were collected for this period. 405 deaths, including 127 cancer deaths, occurred in the cohort. The mortality from all causes and all cancers was significantly lower than in the German population. Total mortality decreased with increasing radiation doses (rate ratio (RR) per 10 mSv: 0.85, 95 % CI: 0.79, 0.93), contrasting with a non-significant increase of cancer mortality (RR per 10 mSv: 1.05, 95 % CI: 0.91, 1.20), which was restricted to the group of cancers not categorized as radiogenic in categorical analyses. While the total and cancer mortality of cockpit crew is low, a positive trend of all cancer with radiation dose is observed. Incomplete adjustment for age, other exposures correlated with duration of employment and a healthy worker survivor effect may contribute to this finding. More information is expected from a pooled analysis of updated international aircrew studies.

Genomic instability in mutation induction on normal human fibroblasts irradiated with chronic low-dose radiations in heavy-ion radiation field

International Nuclear Information System (INIS)

Suzuki, M.; Tsuruoka, C.; Uchihori, Y.; Yasuda, H.; Fujitaka, K.

2003-01-01

Full text: At a time when manned space exploration is more a reality with the planned the International Space Station (ISS) underway, the potential exposure of crews in a spacecraft to chronic low-dose radiations in the field of low-flux galactic cosmic rays (GCR) and the subsequent biological effects have become one of the major concerns of space science. We have studied both in vitro life span and genomic instability in cellular effects in normal human skin fibroblasts irradiated with chronic low-dose radiations in heavy-ion radiation field. Cells were cultured in a CO2 incubator, which was set in the irradiation room for the biological study of heavy ions in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences (NIRS), and irradiated with scattered radiations produced from heavy ions. Absorbed dose measured using a thermoluminescence dosimeter (TLD) and a Si-semiconductor detector was to be around 1.4 mGy per day when operating the HIMAC machine for biological experiments. The total population doubling number (tPDN) of low-dose irradiated cells was significantly smaller (79-93%) than that of unirradiated cells. The results indicate that the life span of the cell population shortens by irradiating with low-dose scattered radiations in the heavy-ion irradiation field. Genomic instability in cellular responses was examined to measure either cell killing or mutation induction in low-dose accumulated cells after exposing to X-ray challenging doses. The results showed that there was no enhanced effect on cell killing between low-dose accumulated and unirradiated cells after exposing to defined challenging doses of 200kV X rays. On the contrary, the mutation frequency on hprt locus of low-dose accumulated cells was much higher than that of unirradiated cells. The results suggested that genomic instability was induced in mutagenesis by the chronic low-dose irradiations in heavy-ion radiation field

Search for the Cosmic Infrared Background Radiation using COBE Data

Science.gov (United States)

Hauser, Michael

2001-01-01

This project was initiated to allow completion of the primary investigation of the Diffuse Infrared Background Experiment (DIRBE) on NASA's Cosmic Background Explorer (CORE) mission, and to study the implications of those findings. The Principal Investigator (PI) on this grant was also the Principal Investigator on the DIRBE team. The project had two specific goals: Goal 1: Seek improved limits upon, or detections of, the cosmic infrared background radiation using data from the COBE Diffuse Infrared Background Experiment (DIRBE). Goal 2: Explore the implications of the limits and measured values of the cosmic infrared background for energy releases in the Universe since the formation of the first luminous sources. Both of these goals have been successfully accomplished.

Angular anisotropy of the cosmic microwave background radiation

International Nuclear Information System (INIS)

Silk, J.

1982-01-01

The theory of fluctuations in the cosmic microwave background radiation is reviewed. Anisotropy on large-scale (dipole and quadrupole) and on small scales is discussed. The smoothing effects of secondary ionization (fractional ionization x) are found to be unimportant over an angular scale greater than approx.= 5(OMEGAx)sup(1/3) degrees. (author)

COMPARISON OF COSMIC-RAY ENVIRONMENTS ON EARTH, MOON, MARS AND IN SPACECARFT USING PHITS.

Science.gov (United States)

Sato, Tatsuhiko; Nagamatsu, Aiko; Ueno, Haruka; Kataoka, Ryuho; Miyake, Shoko; Takeda, Kazuo; Niita, Koji

2017-09-29

Estimation of cosmic-ray doses is of great importance not only in aircrew and astronaut dosimetry but also in evaluation of background radiation exposure to public. We therefore calculated the cosmic-ray doses on Earth, Moon and Mars as well as inside spacecraft, using Particle and Heavy Ion Transport code System PHITS. The same cosmic-ray models and dose conversion coefficients were employed in the calculation to properly compare between the simulation results for different environments. It is quantitatively confirmed that the thickness of physical shielding including the atmosphere and soil of the planets is the most important parameter to determine the cosmic-ray doses and their dominant contributors. The comparison also suggests that higher solar activity significantly reduces the astronaut doses particularly for the interplanetary missions. The information obtained from this study is useful in the designs of the future space missions as well as accelerator-based experiments dedicated to cosmic-ray research. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The new Internet tool: the information and evaluation system by flight, of exposure to cosmic radiation in the new air transports S.I.E.V.E.R.T

International Nuclear Information System (INIS)

2002-03-01

In France, the public authorities put a new Internet tool at air companies disposal, in order they can evaluate the radiations doses received by their flying crews during their flights. This tool called information and evaluation system by flight of exposure to cosmic radiation in air transport (S.I.E.V.E.R.T.). (N.C.)

Demonstration of a stimulating effect of natural ionizing radiation and of very low radiation doses on cell multiplication

International Nuclear Information System (INIS)

Planel, G.; Soleilhavoup, J.P.; Tixador, R.; Croute, F.; Richoilley, G.

1976-01-01

Experiments have been carried out to demonstrate a possible effect of natural ionizing radiation. Using lead shielding devices or an underground laboratory, it was shown that a decrease in background irradiation induces a decrease in cell growth rate (experiments carried out on Paramecia). On the other hand, the recovery of a normal irradiation level in shielding devices induces a quite normal cell proliferation. Moreover, small doses of γ rays from 60 Co exhibit a stimulating effect. Variations in cell radiosensitivity to these low doses are reported. Experiments carried out in the underground laboratory and at high altitude show that both telluric radioactivity and cosmic rays contribute to this stimulating effect on cell multiplication. (author)

Air traffic and cosmic radiation. An epidemiological study among aircraft crews in Germany

International Nuclear Information System (INIS)

Blettner, M.; Hammer, G.P.; Langner, I.; Zeeb, H.

2003-01-01

Airline pilots and cabin crew are exposed to cosmic ionizing radiation and other occupational factors that may influence their health status. The mortality of some 6,000 pilots and 20,000 cabin crew members was investigated in a cohort study. Overall a pronounced healthy worker effect was seen. The cancer mortality risk is slightly lower than in the general population. Currently there is no indication for an increase in cancer mortality due to cosmic radiation. A further follow-up is planned. (orig.) [de

Cosmic background radiation anisotropy in an open inflation, cold dark matter cosmogony

Science.gov (United States)

Kamionkowski, Marc; Ratra, Bharat; Spergel, David N.; Sugiyama, Naoshi

1994-01-01

We compute the cosmic background radiation anisotropy, produced by energy-density fluctuations generated during an early epoch of inflation, in an open cosmological model based on the cold dark matter scenario. At Omega(sub 0) is approximately 0.3-0.4, the Cosmic Background Explorer (COBE) normalized open model appears to be consistent with most observations.

Radiation doses - maps and magnitudes

International Nuclear Information System (INIS)

1989-01-01

A NRPB leaflet in the 'At-a-Glance' Series presents information on the numerous sources and magnitude of exposure of man to radiation. These include the medical use of radiation, radioactive discharges to the environment, cosmic rays, gamma rays from the ground and buildings, radon gas and food and drink. A Pie chart represents the percentage contribution of each of those sources. Finally, the terms becquerel, microsievert and millisievert are explained. (U.K.)

A model for the calculation of the radiation dose from natural radionuclides in The Netherlands

International Nuclear Information System (INIS)

Ackers, J.G.

1986-02-01

A model has been developed to calculate the radiation dose incurred from natural radioactivity indoors and outdoors, expressed in effective dose equivalence/year. The model is applied on a three rooms dwelling characterized by interconnecting air flows and on a dwelling with crawlspace. In this model the distinct parameters are variable in order to allow the investigation of the relative influence. The calculated effective dose equivalent for an adult in the dwelling was calculated to be about 1.7 mSv/year, composed of 15% from cosmic radiation, 35% from terrestrial radioactivity, 20% from radioactivity in the body and 30% from natural radionuclides in building materials. The calculations show an enhancement of about a factor of two in radon concentration in air in a room which is ventilated by air from an adjacent room. It is also shown that the attachment rate of radon products to aerosols and the plate-out effect are relatively important parameters influencing the magnitude of the dose rate. (Auth.)

Snowpack snow water equivalent measurement using the attenuation of cosmic gamma radiation

International Nuclear Information System (INIS)

Osterhuber, R.; Condreva, K.

1998-01-01

Incoming, background cosmic radiation constantly fluxes through the earth's atmosphere. The high energy gamma portion of this radiation penetrates many terrestrial objects, including the winter snowpack. The attenuation of this radiation is exponentially related to the mass of the medium through which it penetrates. For the past three winters, a device measuring cosmic gamma radiation--and its attenuation through snow--has been installed at the Central Sierra Snow Laboratory, near Donner Pass, California. This gamma sensor, measuring energy levels between 5 and 15 MeV, has proved to be an accurate, reliable, non-invasive, non-mechanical instrument with which to measure the total snow water equivalent of a snowpack. This paper analyzes three winters' worth of data and discusses the physics and practical application of the sensor for the collection of snow water equivalent data from a remote location

Population dose due to natural radiation in Hong Kong

International Nuclear Information System (INIS)

Tso, M.Y.W.; Leung, J.K.C.

2000-01-01

In densely populated cities such as Hong Kong where people live and work in high-rise buildings that are all built with concrete, the indoor gamma dose rate and indoor radon concentration are not wide ranging. Indoor gamma dose rates (including cosmic rays) follow a normal distribution with an arithmetic mean of 0.22 ± 0.04 (micro)Gy h -1 , whereas indoor radon concentrations follow a log-normal distribution with geometric means of 48 ± 1 Bq m -3 and 90 ± 2 Bq m -3 for the two main categories of buildings: residential and non-residential. Since different occupations result in different occupancy in different categories of buildings, the annual total dose [indoor and outdoor radon effective dose + indoor and outdoor gamma absorbed dose (including cosmic ray)] to the population in Hong Kong was estimated based on the number of people for each occupation; the occupancy of each occupation; indoor radon concentration distribution and indoor gamma dose rate distribution for each category of buildings; outdoor radon concentration and gamma dose rate; and indoor and outdoor cosmic ray dose rates. The result shows that the annual doses for every occupation follow a log-normal distribution. This is expected since the total dose is dominated by radon effective dose, which has a log-normal distribution. The annual dose to the population of Hong Kong is characterized by a log-normal distribution with a geometric mean of 2.4 mSv and a geometric standard deviation of 1.3 mSv

STARLIFE - An International Campaign to Study the Role of Galactic Cosmic Radiation in Astrobiological Model Systems

Science.gov (United States)

Moeller, Ralf; Raguse, Marina; Leuko, Stefan; Berger, Thomas; Hellweg, Christine Elisabeth; Fujimori, Akira; Okayasu, Ryuichi; Horneck, Gerda

2017-02-01

In-depth knowledge regarding the biological effects of the radiation field in space is required for assessing the radiation risks in space. To obtain this knowledge, a set of different astrobiological model systems has been studied within the STARLIFE radiation campaign during six irradiation campaigns (2013-2015). The STARLIFE group is an international consortium with the aim to investigate the responses of different astrobiological model systems to the different types of ionizing radiation (X-rays, γ rays, heavy ions) representing major parts of the galactic cosmic radiation spectrum. Low- and high-energy charged particle radiation experiments have been conducted at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility at the National Institute of Radiological Sciences (NIRS) in Chiba, Japan. X-rays or γ rays were used as reference radiation at the German Aerospace Center (DLR, Cologne, Germany) or Beta-Gamma-Service GmbH (BGS, Wiehl, Germany) to derive the biological efficiency of different radiation qualities. All samples were exposed under identical conditions to the same dose and qualities of ionizing radiation (i) allowing a direct comparison between the tested specimens and (ii) providing information on the impact of the space radiation environment on currently used astrobiological model organisms.

Long-range correlation in cosmic microwave background radiation.

Science.gov (United States)

Movahed, M Sadegh; Ghasemi, F; Rahvar, Sohrab; Tabar, M Reza Rahimi

2011-08-01

We investigate the statistical anisotropy and gaussianity of temperature fluctuations of Cosmic Microwave Background (CMB) radiation data from the Wilkinson Microwave Anisotropy Probe survey, using the Multifractal Detrended Fluctuation Analysis, Rescaled Range, and Scaled Windowed Variance methods. Multifractal Detrended Fluctuation Analysis shows that CMB fluctuations has a long-range correlation function with a multifractal behavior. By comparing the shuffled and surrogate series of CMB data, we conclude that the multifractality nature of the temperature fluctuation of CMB radiation is mainly due to the long-range correlations, and the map is consistent with a gaussian distribution.

Registration of radiation doses

International Nuclear Information System (INIS)

2000-02-01

In Finland the Radiation and Nuclear Safety Authority (STUK) is maintaining the register (called Dose Register) of the radiation exposure of occupationally exposed workers in order to ensure compliance with the principles of optimisation and individual protection. The guide contains a description of the Dose Register and specifies the responsibilities of the party running a radiation practice to report the relevant information to the Dose Register

Dose loading for civil aircraft crews

International Nuclear Information System (INIS)

Rumyantsev, V.V.

1993-01-01

The results of studying cosmic radiation effects on dose loadings for civil aviation personnel are discussed. The problems connected with health protection and radiation safety provisions for aviation personnels of subsonic and supersonic passenger airplans are considered

Elucidation of the fluctuation history of cosmic radiation and global environmental using AMS

International Nuclear Information System (INIS)

Horiuchi, Kazuho

2008-01-01

Recently, accuracy of AMS has further been raised in trace amounts of sample. Besides application of 14 C to the age estimation, it has been able to restore in detail the past fluctuation of cosmic radiation strength using the other radioactive isotopes ( 10 Be, 36 Cl etc) in environmental samples and to elucidate the correlation of this with the fluctuation of climate and environment. In this report, the attempts to elucidate the fluctuation history of cosmic radiation and global environment with ice cores using AMS are presented. (M.H.)

Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

Science.gov (United States)

Madau, Piero; Fragos, Tassos

2017-05-01

We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior to and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z ≲ 4. Together with an updated empirical determination of the cosmic history of star formation, recent modeling of the stellar mass-metallicity relation, and a scheme for absorption by the IGM that accounts for the presence of ionized H II bubbles during the epoch of reionization, our detailed calculations provide refined predictions of the X-ray volume emissivity and filtered radiation background from “normal” galaxies at z ≳ 6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. Because of the energy dependence of photoabsorption, soft X-ray photons are produced by local sources, while more energetic radiation arrives unattenuated from larger cosmological volumes. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct He I photoionizations are the main source of IGM heating, and the temperature of the largely neutral medium in between H II cavities increases above the temperature of the cosmic microwave background (CMB) only at z ≲ 10, when the volume filling factor of H II bubbles is already ≳0.1. Therefore, in this scenario, it is only at relatively late epochs that neutral intergalactic hydrogen

Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

Energy Technology Data Exchange (ETDEWEB)

Madau, Piero [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Fragos, Tassos [Geneva Observatory, University of Geneva, Chemin des Maillettes 51, 1290 Sauverny (Switzerland)

2017-05-01

We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior to and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z ≲ 4. Together with an updated empirical determination of the cosmic history of star formation, recent modeling of the stellar mass–metallicity relation, and a scheme for absorption by the IGM that accounts for the presence of ionized H ii bubbles during the epoch of reionization, our detailed calculations provide refined predictions of the X-ray volume emissivity and filtered radiation background from “normal” galaxies at z ≳ 6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. Because of the energy dependence of photoabsorption, soft X-ray photons are produced by local sources, while more energetic radiation arrives unattenuated from larger cosmological volumes. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct He i photoionizations are the main source of IGM heating, and the temperature of the largely neutral medium in between H ii cavities increases above the temperature of the cosmic microwave background (CMB) only at z ≲ 10, when the volume filling factor of H ii bubbles is already ≳0.1. Therefore, in this scenario, it is only at relatively late epochs that neutral intergalactic

Interpretation of observed cosmic microwave background radiation

International Nuclear Information System (INIS)

Alfven, H.; Mendis, A.

1977-01-01

It is stated that the observed cosmic microwave background radiation, which closely fits a 2.7 K black body spectrum, is generally claimed to be the strongest piece of evidence in support of hot big bang cosmologies by its proponents. It is here stated that the observed radiation corresponds to the distribution of dust in galaxies or protogalaxies with a temperature approximately 110 K at the epoch corresponding to Z approximately 40, and not to a plasma of temperature > approximately 3000 K at an earlier epoch (Z > approximately 1000), as indicated by the canonical model of big bang cosmologies. The claim that the latter lends strong support to hot big bang cosmologies is stated to be without foundation. It is concluded that the microwave background radiation must be explained not in terms of a coupling between matter and radiation at the present epoch, but in terms of a coupling in a previous epoch within the framework of an evolutionary cosmology. (U.K.)

Investigation of energy spectrum and nuclear interactions of primary cosmic radiation; Badanie widma energetycznego i oddzialywan jadrowych pierwotnego promieniowania kosmicznego

Energy Technology Data Exchange (ETDEWEB)

Wilczynski, H. [Dept. of High Energy Physics, The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

1996-12-31

In the paper the JACEE experiment data analysis: energy spectra in the energy range 10{sup 12} - 10{sup 15} eV of different nuclides in cosmic radiation and some aspects of nuclear interactions at energy above 10{sup 12} eV/nucleon is presented. The data were compared with results of theory of cosmic radiation acceleration by striking waves arises from supernova stars explosions. In the interactions of cosmic radiation nuclei the short-lived particles production has been observed what agrees with long-distance component of cascades initiated by cosmic radiation interactions. In one case an interaction with asymmetric photons emission were observed 72 refs, 33 figs, 4 tabs

Radiation Protection Concepts and Quantities for the Occupational Exposure to Cosmic Radiation

International Nuclear Information System (INIS)

Bartlett, D.T.

1999-01-01

For the purposes of dose limitation and dose control, the harm, or detriment, of exposure to radiation is assessed by the quantity effective dose. Effective dose is evaluated by the application of factors to the averaged absorbed dose in the organs and tissues of the body. Radiation monitoring instruments are generally calibrated in terms of the quantity ambient dose equivalent which is defined in a simple spherical phantom. The relationship of these quantities is described. Requirements for the radiation protection of aircraft crew are given in the European Union Council Directive 96/29/EURATOM. There are requirements to assess the exposure of aircraft crew, to inform them of health risks, to reduce higher doses, and to control the dose to the foetus. There are no explicit dose limits, other than a dose objective to be applied to the exposure of the foetus, and no requirements for designation of areas or classification of workers. There are significant differences between the exposure condition of aircraft crew and workers in most other industries where there is occupational exposure to radiation. There are greater ranges of radiation types and energy, and there are different dose distributions and characteristics of the working populations. However, the field intensity is predictable and, with the exception of rare solar events, there is no risk of significant unexpected exposures. Dose assessment is anticipated to be by folding staff roster information with estimates of route doses, since there is little variability of dose rate within an aircraft. Route doses, which may be either an agreed average value for a given airport pairing and aircraft type, or be flight specific, will be closely linked to measured values. Requirements as to the accuracy of dose assessment should be applied which are broadly similar to those used in individual monitoring generally. (author)

Cosmic thermalization and the microwave background radiation

International Nuclear Information System (INIS)

Rana, N.C.

1981-01-01

A different origin of the microwave background radiation (MBR) is suggested in view of some of the difficulties associated with the standard interpretation. Extensive stellar-type nucleosynthesis could provide radiation with the requisite energy density of the MBR and its spectral features are guaranteed by adequate thermalization of the above radiation by an ambient intergalactic dust medium. This thermalization must have occurred in quite recent epochs, say around epochs of redshift z = 7. The model emerges with consistent limits on the cosmic abundance of helium, the general luminosity evolution of the extragalactic objects, the baryonic matter density in the Universe (or, equivalently the deceleration parameter) and the degree of isotropy of MBR. The model makes definite predictions on issues like the properties of the intergalactic thermalizers, the degree of isotropy of MBR at submillimetre wavelengths and cluster emission in the far infrared. (author)

Air dose rate in Aichi Prefecture

International Nuclear Information System (INIS)

Ohnuma, Shoko; Chaya, Kunio; Tomita, Banichi; Aoyama, Kan; Yamada, Naoki; Yamada, Masuo; Hamamura, Norikatsu

1985-01-01

We have carried out the observations of air dose rate during 1964--1983 at the fixed points of Aichi Prefecture and investigated the distribution of air dose rate in this prefecture during 1979--1983. The results of these researches are as follows. 1) The apparent half time of radiation dose from the earth and the atmosphere during the last 20 years was about 9.7 years and it was longer than the apparent half time of fallout total β radioactivity in every rainfall that was about 3.2 years. 2) The influence of nuclear explosion test in China on the measurements of air does rate did not existed directly during the latter half of 20 years, not so as during the former and it was keeping decreasing. It was expected that the air dose rate would begin to indicate the natural radiation dose from the earth and the atmosphere in the near future. 3) The distribution of air dose rate in this prefecture depended strongly on the geology. The maximum value was 5.6 μR/hr (except cosmic rays) in Fujioka Cho, the minimum value was 1.9 μR/hr (except cosmic rays) in Tahara Cho and the average in the whole prefecture was 3.5+-0.7 μR/hr (except cosmic rays). 4) It was estimated that the radiation dose which the inhabitants received from the earth and the atmosphere was 17--52 m rem a year and the average was 31 m rem a year. (author)

Air dose rate in Aichi Prefecture

Energy Technology Data Exchange (ETDEWEB)

Ohnuma, Shoko; Chaya, Kunio; Tomita, Banichi; Aoyama, Kan; Yamada, Naoki; Yamada, Masuo; Hamamura, Norikatsu

1985-03-01

We have carried out the observations of air dose rate during 1964-1983 at the fixed points of Aichi Prefecture and investigated the distribution of air dose rate in this prefecture during 1979-1983. The results of these researches are as follows. 1) The apparent half time of radiation dose from the earth and the atmosphere during the last 20 years was about 9.7 years and it was longer than the apparent half time of fallout total ..beta.. radioactivity in every rainfall that was about 3.2 years. 2) The influence of nuclear explosion test in China on the measurements of air does rate did not existed directly during the latter half of 20 years, not so as during the former and it was keeping decreasing. It was expected that the air dose rate would begin to indicate the natural radiation dose from the earth and the atmosphere in the near future. 3) The distribution of air dose rate in this prefecture depended strongly on the geology. The maximum value was 5.6 ..mu..R/hr (except cosmic rays) in Fujioka Cho, the minimum value was 1.9 ..mu..R/hr (except cosmic rays) in Tahara Cho and the average in the whole prefecture was 3.5 +- 0.7 ..mu..R/hr (except cosmic rays). 4) It was estimated that the radiation dose which the inhabitants received from the earth and the atmosphere was 17-52 m rem a year and the average was 31 m rem a year.

Nuclear interactions between cosmic radiation and interstellar gas, and nucleosynthesis of lithium, beryllium, and boron

International Nuclear Information System (INIS)

Meneguzzi, Maurice.

1975-01-01

The effects of nuclear interactions between the nuclei of cosmic radiation and those of interstellar gas were studied. The variation in the chemical composition of cosmic radiation with energy shows that the quantity of matter it passes through decreases between 1 and 100GeV/nucleon from 6 to 1g/cm 2 approximately. The chemical and isotopic composition for C, N and O suggests that the relative abundances of these nuclei at the source are much the same as the universal abundances except for the ratio C/O, higher by about a factor 1.5 in cosmic radiation sources. The enrichment of interstellar gas in light elements Li, Be and B was calculated. The value obtained accounts well for the universal abundances of the four isotopes 6 Li, 9 Be, 10 B, 11 B independently of the model used. It may be assumed that large fluxes of low-energy cosmic rays exist in the remains of supernovae and that 7 Li is produced in these objects and then spread out in the galaxy. These objects could be extended sources of nuclear γ's, which are observable, but the same process proves unable to produce sufficient quantities of the very heavy proton-rich elements of dubious origin. Inelastic collisions or spallation reactions between cosmic and interstellar gas nuclei induce a quantity of nuclear γ ray emission not necessarily undetectable. The position flux of a few MeV from the β + disintegration of unstable spallation products is too low on the other hand to give an estimate of the low-energy cosmic radiation flux in the interstellar medium [fr

Radiation doses to Finns

International Nuclear Information System (INIS)

Rantalainen, L.

1996-01-01

The estimated annual radiation doses to Finns have been reduced in the recent years without any change in the actual radiation environment. This is because the radiation types have been changed. The risk factors will probably be changed again in the future, because recent studies show discrepancies in the neutron dosimetry concerning the city of Hiroshima. Neutron dosimetry discrepancy has been found between the predicted and estimated neutron radiation. The prediction of neutron radiation is calculated by Monte Carlo simulations, which have also been used when designing recommendations for the limits of radiation doses (ICRP60). Estimation of the neutron radiation is made on the basis of measured neutron activation of materials in the city. The estimated neutron dose beyond 1 km is two to ten, or more, times as high as the predicted dose. This discrepancy is important, because the most relevant distances with respect to radiation risk evaluation are between 1 and 2 km. Because of this discrepancy, the present radiation risk factors for gamma and neutron radiation, which rely on the Monte Carlo calculations, are false, too. The recommendations of ICRP60 have been adopted in a few countries, including Finland, and they affect the planned common limits of the EU. It is questionable whether happiness is increased by adopting false limits, even if they are common. (orig.) (2 figs., 1 tab.)

Ionizing radiation population doses at Sao Paulo city, Brazil: open-pit gamma dose measurement

International Nuclear Information System (INIS)

Oliveira, Raimundo Enoch Rodrigues

2001-01-01

The effects of ionizing radiation to the human beings are well known for high and intermediate doses. As far as low level) radiation doses are concerned, there is no consensus. In order to get a better understanding of such effects it is necessary to assess the low doses with better accuracy. In this work, it was made an estimate of the annual ambient dose equivalent (H * (10)) to which the people are exposed in the city of Sao Paulo. Until now there are no data about it available in the literature. For the purpose of this evaluation, a map with various routes covering the largest and more representative area of the city was designed. The choice of points for data collection was made taking into account mainly the occupancy of the region. A portable gamma spectrometry system was used. It furnishes the rate of H * (10) and the measured gamma spectrum (in the range from 50 to 1670 keV) in the place of interest. The measurements were performed in a short time interval, since the gamma radiation arrives from a great extent of soil. Each measurement was done 1 m above the soil during 300 s. The rates of H * (10) varied from 33.1 to 152.3 nSv.h -1 , net values, obtained after subtraction of the cosmic rays contribution. The standard deviation was 22 n Sv.h -1 for an average for the city of Sao Paulo of 96.1(24) nSv.h -1 . In addition, average values of H * (10) rates for the city Health Divisions were calculated. Those values are not statistically equivalent and the whole set of data could not be treated as one, as the statistical Student test indicated a non homogeneity of the group of data. Hence it is necessary the accomplishment of a more detailed survey in order to verify the origin of the discrepancy. The mean value of H * (10) rate obtained for the city of Sao Paulo as converted to effective dose. in order to be compared with other places results It could be noticed that the annual average of effective dose for the city of Sao Paulo, 0.522(13) mSv, is superior to

Radiation dose monitoring in the clinical routine

Energy Technology Data Exchange (ETDEWEB)

Guberina, Nika [UK Essen (Germany). Radiology

2017-04-15

Here we describe the first clinical experiences regarding the use of an automated radiation dose management software to monitor the radiation dose of patients during routine examinations. Many software solutions for monitoring radiation dose have emerged in the last decade. The continuous progress in radiological techniques, new scan features, scanner generations and protocols are the primary challenge for radiation dose monitoring software systems. To simulate valid dose calculations, radiation dose monitoring systems have to follow current trends and stay constantly up-to-date. The dose management software is connected to all devices at our institute and conducts automatic data acquisition and radiation dose calculation. The system incorporates 18 virtual phantoms based on the Cristy phantom family, estimating doses in newborns to adults. Dose calculation relies on a Monte Carlo simulation engine. Our first practical experiences demonstrate that the software is capable of dose estimation in the clinical routine. Its implementation and use have some limitations that can be overcome. The software is promising and allows assessment of radiation doses, like organ and effective doses according to ICRP 60 and ICRP 103, patient radiation dose history and cumulative radiation doses. Furthermore, we are able to determine local diagnostic reference doses. The radiation dose monitoring software systems can facilitate networking between hospitals and radiological departments, thus refining radiation doses and implementing reference doses at substantially lower levels.

Radiative processes of two entangled atoms in cosmic string spacetime

Science.gov (United States)

Cai, Huabing; Ren, Zhongzhou

2018-01-01

We investigate the radiative processes of two static two-level atoms in a maximally entangled state coupled to vacuum electromagnetic field in the cosmic string spacetime. We find that the decay rate from the entangled state to the ground state crucially depends on the atomic separation, the polarization directions of the individual atoms, the atom-string distance and the deficit angle induced by the string. As the atom-string distance increases, the decay rate oscillates around the result in Minkowski spacetime and the amplitude gradually decreases. The oscillation is more severe for larger planar angle deficit. We analyze the decay rate in different circumstances such as near zone and specific polarization cases. Some comparisons between symmetric and antisymmetric states are performed. By contrast with the case in Minkowski spacetime, we can reveal the effects of the cosmic string on the radiative properties of the entangled atoms.

Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights

Science.gov (United States)

Denkins, P.; Badhwar, G.; Obot, V.; Wilson, B.; Jejelewo, O.

2001-01-01

NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far. the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space. exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation

Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights

Science.gov (United States)

Denkins, Pamela; Badhwar, Gautam; Obot, Victor; Wilson, Bobby; Jejelewo, Olufisayo

2001-08-01

NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far, the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space, exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation

Radiation doses in interventional neuroradiology

International Nuclear Information System (INIS)

Theodorakou, C.; Butler, P.; Horrocks, J.A.

2001-01-01

Patient radiation doses during interventional radiology (IR) procedures may reach the thresholds for radiation-induced skin and eye lens injuries. This study investigates the radiation doses received by patients undergoing cerebral embolization. Measurements were conducted using thermoluminescent dosimeters. Radiotherapy verification films were used in order to visualise the radiation field. For each procedure the fluoroscopic and digital dose-area product, the fluoroscopic time, the total number of acquired images and entrance-skin dose calculated by the angiographic unit were recorded. In this paper, the skin, eye and thyroid glands doses on a sample of patients are presented. From a preliminary study of 13 patients having undergone cerebral embolization, it was deduced that six of them have received a dose above 1 Gy. Detailed dose data from patients undergoing IR procedures will be collected in the future with the aim of developing a model to allow estimation of the dose prior to the procedure as well as to look at techniques of dose reduction. (author)

Labour cost of radiation dose

International Nuclear Information System (INIS)

Cook, A.; Lockett, L.E.

1978-01-01

In order to optimise capital expenditure on measures to protect workers against radiation it would be useful to have a means to measure radiation dose in money terms. Because labour has to be employed to perform radiation work there must be some relationship between the wages paid and the doses received. Where the next increment of radiation dose requires additional labour to be recruited the cost will at least equal the cost of the extra labour employed. This paper examines some of the factors which affect the variability of the labour cost of radiation dose and notes that for 'in-plant' exposures the current cost per rem appears to be significantly higher than values quoted in ICRP Publication 22. An example is given showing how this concept may be used to determine the capital it is worth spending on installed plant to prevent regular increments of radiation dose to workers. (author)

Radiation dose in dental radiology

International Nuclear Information System (INIS)

Cohnen, M.; Kemper, J.; Moedder, U.; Moebes, O.; Pawelzik, J.

2002-01-01

The aim of this study was to compare radiation exposure in panoramic radiography (PR), dental CT, and digital volume tomography (DVT). An anthropomorphic Alderson-Rando phantom and two anatomical head phantoms with thermoluminescent dosimeters fixed at appropriate locations were exposed as in a dental examination. In PR and DVT, standard parameters were used while variables in CT included mA, pitch, and rotation time. Image noise was assessed in dental CT and DVT. Radiation doses to the skin and internal organs within the primary beam and resulting from scatter radiation were measured and expressed as maximum doses in mGy. For PR, DVT, and CT, these maximum doses were 0.65, 4.2, and 23 mGy. In dose-reduced CT protocols, radiation doses ranged from 10.9 to 6.1 mGy. Effective doses calculated on this basis showed values below 0.1 mSv for PR, DVT, and dose-reduced CT. Image noise was similar in DVT and low-dose CT. As radiation exposure and image noise of DVT is similar to low-dose CT, this imaging technique cannot be recommended as a general alternative to replace PR in dental radiology. (orig.)

Irradiation of the Bulgarian population with secondary cosmic radiation

International Nuclear Information System (INIS)

Vasilev, G.

1983-01-01

The radiation of the Bulgarian population was estimated, the former being due to secondary space radiation. A method of calculation was applied using the values for dose powers at different heights, proposed by the Research Committee on Atomic Radiation Action (UNO, 1976). Parallelly with that comparative measurements were taken using counters for space radiation VA-Z-232. The stay of the population in different type buildings was taken into account. The mean annual dose of radiation of the Bulgarian population from the secondary space radiation is 245μGy, and the collective effective equivalent dose is 2, 2.10 3 hum sv. (authors)

Cosmic microwave background radiation anisotropies in brane worlds.

Science.gov (United States)

Koyama, Kazuya

2003-11-28

We propose a new formulation to calculate the cosmic microwave background (CMB) spectrum in the Randall-Sundrum two-brane model based on recent progress in solving the bulk geometry using a low energy approximation. The evolution of the anisotropic stress imprinted on the brane by the 5D Weyl tensor is calculated. An impact of the dark radiation perturbation on the CMB spectrum is investigated in a simple model assuming an initially scale-invariant adiabatic perturbation. The dark radiation perturbation induces isocurvature perturbations, but the resultant spectrum can be quite different from the prediction of simple mixtures of adiabatic and isocurvature perturbations due to Weyl anisotropic stress.

Dose reconstruction modeling for medical radiation workers

International Nuclear Information System (INIS)

Choi, Yeong Chull; Cha, Eun Shil; Lee, Won Jin

2017-01-01

Exposure information is a crucial element for the assessment of health risk due to radiation. Radiation doses received by medical radiation workers have been collected and maintained by public registry since 1996. Since exposure levels in the remote past are greater concern, it is essential to reconstruct unmeasured doses in the past using known information. We developed retrodiction models for different groups of medical radiation workers and estimate individual past doses before 1996. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure.

Dose reconstruction modeling for medical radiation workers

Energy Technology Data Exchange (ETDEWEB)

Choi, Yeong Chull; Cha, Eun Shil; Lee, Won Jin [Dept. of Preventive Medicine, Korea University, Seoul (Korea, Republic of)

2017-04-15

Exposure information is a crucial element for the assessment of health risk due to radiation. Radiation doses received by medical radiation workers have been collected and maintained by public registry since 1996. Since exposure levels in the remote past are greater concern, it is essential to reconstruct unmeasured doses in the past using known information. We developed retrodiction models for different groups of medical radiation workers and estimate individual past doses before 1996. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure.

Cosmic background radiation spectral distortion and radiative decays of relic neutral particles

International Nuclear Information System (INIS)

Berezhiani, Z.G.; Doroshkevich, A.G.; Khlopov, M.Yu.; Yurov, V.P.; Vysotskij, M.I.

1989-01-01

The recently observed excess of photons on a short wavelength side of the peak of a cosmic background radiation spectrum can be described by radiative decays of relic neutral particles. The lifetime and mass of a decaying particle must satisfy the following conditions: 2x10 9 s 14 s, 0.4 eV -9 -8x10 -8 ) μ b , and the interaction of new particles with the usual matter must be rather strong. The generalization of the standard SU(3)xSU(2)xU(1) model is presented which includes new particles with the desired properties. 18 refs.; 3 figs.; 2 tabs

The natural radiation background

International Nuclear Information System (INIS)

Duggleby, J.C.

1982-01-01

The components of the natural background radiation and their variations are described. Cosmic radiation is a major contributor to the external dose to the human body whilst naturally-occurring radionuclides of primordial and cosmogenic origin contribute to both the external and internal doses, with the primordial radionuclides being the major contributor in both cases. Man has continually modified the radiation dose to which he has been subjected. The two traditional methods of measuring background radiation, ionisation chamber measurements and scintillation counting, are looked at and the prospect of using thermoluminescent dosimetry is considered

Development of radiation dose assessment system for radiation accident (RADARAC)

International Nuclear Information System (INIS)

Takahashi, Fumiaki; Shigemori, Yuji; Seki, Akiyuki

2009-07-01

The possibility of radiation accident is very rare, but cannot be regarded as zero. Medical treatments are quite essential for a heavily exposed person in an occurrence of a radiation accident. Radiation dose distribution in a human body is useful information to carry out effectively the medical treatments. A radiation transport calculation utilizing the Monte Carlo method has an advantageous in the analysis of radiation dose inside of the body, which cannot be measured. An input file, which describes models for the accident condition and quantities of interest, should be prepared to execute the radiation transport calculation. Since the accident situation, however, cannot be prospected, many complicated procedures are needed to make effectively the input file soon after the occurrence of the accident. In addition, the calculated doses are to be given in output files, which usually include much information concerning the radiation transport calculation. Thus, Radiation Dose Assessment system for Radiation Accident (RADARAC) was developed to derive effectively radiation dose by using the MCNPX or MCNP code. RADARAC mainly consists of two parts. One part is RADARAC - INPUT, which involves three programs. A user can interactively set up necessary resources to make input files for the codes, with graphical user interfaces in a personnel computer. The input file includes information concerning the geometric structure of the radiation source and the exposed person, emission of radiations during the accident, physical quantities of interest and so on. The other part is RADARAC - DOSE, which has one program. The results of radiation doses can be effectively indicated with numerical tables, graphs and color figures visibly depicting dose distribution by using this program. These results are obtained from the outputs of the radiation transport calculations. It is confirmed that the system can effectively make input files with a few thousand lines and indicate more than 20

Cloud chamber photographs of the cosmic radiation

CERN Document Server

Rochester, George Dixon

1952-01-01

Cloud Chamber Photographs of the Cosmic Radiation focuses on cloud chamber and photographic emulsion wherein the tracks of individual subatomic particles of high energy are studied. The publication first offers information on the technical features of operation and electrons and cascade showers. Discussions focus on the relationship in time and space of counter-controlled tracks; techniques of internal control of the cloud chamber; cascade processes with artificially-produced electrons and photons; and nuclear interaction associated with an extensive shower. The manuscript then elaborates on

Cosmic rays: an in-flight hazard?

International Nuclear Information System (INIS)

O'Sullivan, Denis

2000-01-01

International airlines are collaborating with physicists to assess whether aircrew are at risk from cosmic radiation as routine monitoring will soon become mandatory. Recently, an international team of physicists has joined forces with NASA and several European airlines to study in detail how the radiation field varies inside the atmosphere depending on the altitude, latitude and solar activity. Astronauts are subjected to the full intensity of high-energy cosmic rays and solar particles (together with the secondary particles produced in the spacecraft walls), and the biological risks in space are the subject of ongoing investigations. A typical return mission to Mars, for example, could result in a total ''dose equivalent'' of up to 0.5 sievert. The dose equivalent takes into account the harm caused by a particular type of radiation. Current estimates suggest that a person who receives a 1 sievert dose of ionizing radiation incurs a few per cent increase in the risk of contracting fatal cancer in his or her lifetime, although the risk level depends on sex and age. The radiation we observe at aircraft altitudes of typically 10-12 km is due to very high-energy particles mainly protons and helium nuclei, together with a small amount of heavy nuclei penetrating the atmosphere and colliding with air atoms. These collisions give rise to the production of more particles, such as protons, neutrons and various mesons. A cascade of particles is then produced by successive interactions as they penetrate deeper into the atmosphere. As a result, the flux of particles increases in the upper atmosphere and reaches a maximum at about 20 km above sea level. Below this point, the number of particles decreases due to energy losses and various particle interactions. Happily, at the Earth's surface we are protected by the air above us, which provides the same degree of shielding as a layer of water 10 m thick. The small amount of radiation that eventually reaches us in the form of

Adaptation of radiation shielding code to space environment

International Nuclear Information System (INIS)

Okuno, Koichi; Hara, Akihisa

1992-01-01

Recently, the trend to the development of space has heightened. To the development of space, many problems are related, and as one of them, there is the protection from cosmic ray. The cosmic ray is the radiation having ultrahigh energy, and there was not the radiation shielding design code that copes with cosmic ray so far. Therefore, the high energy radiation shielding design code for accelerators was improved so as to cope with the peculiarity that cosmic ray possesses. Moreover, the calculation of the radiation dose equivalent rate in the moon base to which the countermeasures against cosmic ray were taken was simulated by using the improved code. As the important countermeasures for the safety protection from radiation, the covering with regolith is carried out, and the effect of regolith was confirmed by using the improved code. Galactic cosmic ray, solar flare particles, radiation belt, the adaptation of the radiation shielding code HERMES to space environment, the improvement of the three-dimensional hadron cascade code HETCKFA-2 and the electromagnetic cascade code EGS 4-KFA, and the cosmic ray simulation are reported. (K.I.)

Carcinogenesis induced by low-dose radiation

Directory of Open Access Journals (Sweden)

Piotrowski Igor

2017-11-01

Full Text Available Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

Cosmic gamma radiation of ultra high energy of primordial origin

International Nuclear Information System (INIS)

Aquino Filho, F.G. de.

1984-01-01

The quantum mechanical effects near a collapsing black hole as shown by Stephen W.Hawking in 1974 to produce streaming particles through tunneling effect was explored in the context of cosmic gamma ray production. In this thesis, we show the possible production of gamma rays of high energies (ν approx 10 41 Hz) in the initial stages of the formation of the Universe by the explosion of primordial mini black holes. These mini black hole explosions happening at 10 -43 s to 10 -37 s after the start perhaps may account for the existing universal cosmic background radiation of 2.7 0 K. (Author) [pt

Biological influence from low dose and low-dose rate radiation

International Nuclear Information System (INIS)

Magae, Junji

2007-01-01

Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

Low dose radiation enhance the anti-tumor effect of high dose radiation on human glioma cell U251

International Nuclear Information System (INIS)

Wang Chang; Wang Guanjun; Tan Yehui; Jiang Hongyu; Li Wei

2008-01-01

Objective: To detect the effect on the growth of human glioma cell U251 induced by low dose irradiation and low dose irradiation combined with large dose irradiation. Methods: Human glioma cell line U251 and nude mice carried with human glioma were used. The tumor cells and the mice were treated with low dose, high dose, and low dose combined high dose radiation. Cells growth curve, MTT and flow cytometry were used to detect the proliferation, cell cycle and apoptosis of the cells; and the tumor inhibition rate was used to assess the growth of tumor in vivo. Results: After low dose irradiation, there was no difference between experimental group and control group in cell count, MTT and flow cytometry. Single high dose group and low dose combined high dose group both show significantly the suppressing effect on tumor cells, the apoptosis increased and there was cell cycle blocked in G 2 period, but there was no difference between two groups. In vivo apparent anti-tumor effect in high dose radiation group and the combining group was observed, and that was more significant in the combining group; the prior low dose radiation alleviated the injury of hematological system. There was no difference between single low dose radiation group and control. Conclusions: There is no significant effect on human glioma cell induced by low dose radiation, and low dose radiation could not induce adaptive response. But in vivo experience, low dose radiation could enhance the anti-tumor effect of high dose radiation and alleviated the injury of hematological system. (authors)

Department of Cosmic Radiation Physics: Overview

International Nuclear Information System (INIS)

Gawin, J.

1999-01-01

Full text: The Department of Cosmic Ray Physics in Lodz is involved in basic research in the area of high energy physics and cosmic ray physics related to: - Studies of asymptotic properties of hadronic interactions based on the analysis of cosmic ray propagation in the atmosphere. - Experimental and phenomenological studies of Extensive Air Showers induced by cosmic ray particles. - Search for point sources of high energy cosmic rays. - Studies of cosmic ray propagation in the Galaxy and mechanisms of particle acceleration. - Studies of mass composition of cosmic rays in the energy range 10 15 - 10 17 eV. Theoretical and experimental studies of Extensive Air Shower properties are performed mostly based on the results obtained by the Lodz Extensive Air Shower Array. We analysed nearly 100,000 events of energies above 10 15 eV registered by the Lodz hodoscope. We have developed the method of data analysis which allows us to verify different models of cosmic ray mass composition. In our research in high energy cosmic rays we also used experimental data from other collaborating experiments in Karlsruhe, Baksan and THEMISTOCLE. The Lodz group collaborates with many foreign institutes and laboratories in construction and data interpretation of cosmic ray experiments. Our most important partners are: Forschungszentrum in Karlsruhe (Germany), College de France, Institute for Nuclear Studies of the Russian Academy of Science, University of Perpignan and Uppsala University (Sweden). (author)

Department of Cosmic Radiation Physics - Overview

International Nuclear Information System (INIS)

Gawin, J.

1997-01-01

Full text: The Department of Cosmic Ray Physics in Lodz is involved in basic research in the area of high energy physics and cosmic ray physics related to: -Studies of the asymptotic properties of hadronic interactions from the analysis of cosmic ray propagation in the atmosphere. -Studies of structure and properties of Extensive Air Showers induced by cosmic ray particles. -Search for point sources of high energy cosmic rays. -Studies of cosmic ray propagation in the Galaxy and mechanisms of particle acceleration. -Studies of the mass composition of cosmic rays in the energy range 10 15 -10 17 eV. Theoretical and experimental studies of nuclear interactions for energies exceeding those obtained by modern particle accelerators are performed employing results obtained by the Lodz Extensive Air Shower Array. The Lodz hodoscope can register electromagnetic components of cosmic ray showers in the atmosphere as well as muons at two energy thresholds. Data collected by the Lodz array are also used to study mass composition of cosmic rays in the energy range 10 15 - 10 17 eV. The Lodz group collaborates with foreign institutes and laboratories on construction and data interpretation of cosmic ray experiments. Our most important partners are: Forschungszentrum Karlsruhe (Germany), College de France, the Institute for Nuclear Studies of the Russian Academy of Sciences, the University of Durham, and the University of Perpignan. (author)

Doses to the red bone marrow of young people and adults from radiation of natural origin

International Nuclear Information System (INIS)

Kendall, G M; Fell, T P

2011-01-01

Natural radiation sources comprise cosmic rays, terrestrial gamma rays, radionuclides in food and inhaled isotopes of radon with their decay products. These deliver doses to all organs and tissues including red bone marrow (RBM), the tissue in which leukaemia is thought to originate. In this paper we calculate the age-dependent annual RBM doses from natural radiation sources to young people and to adults at average levels of exposure in the UK. The contributions to dose are generally less complex than in the case of doses to foetuses and young children where it is necessary to take into account transfer of radionuclides across the placenta, intakes in mother's milk and changes in gut uptake in young infants. However, there is high uptake of alkaline earths and of similar elements in the developing skeleton and this significantly affects the doses from radioisotopes of these elements, not just in the teens and twenties but through into the fifth decade of life. The total equivalent dose to the RBM from all natural sources of radiation at age 15 years is calculated to be about 1200 μSv a year at average UK levels, falling to rather less than 1100 μSv per year in later life; the gentle fall from the late teens onwards reflects the diminishing effect of the high uptakes of radioisotopes of the alkaline earths and of lead in this period. About 60% of the equivalent dose is contributed by the low linear energy transfer (LET) component. Radionuclides in food make the largest contribution to equivalent doses to RBM and much the largest contribution to the absorbed dose from high LET radiation (mainly alpha particles).

Doses to the red bone marrow of young people and adults from radiation of natural origin

Energy Technology Data Exchange (ETDEWEB)

Kendall, G M [Childhood Cancer Research Group, University of Oxford, Richards Building, Old Road Campus, Headington, Oxford OX3 7LG (United Kingdom); Fell, T P, E-mail: Gerald.Kendall@ccrg.ox.ac.uk [Health Protection Agency, CRCE, Chilton, Didcot OX11 0RQ, Oxon (United Kingdom)

2011-09-01

Natural radiation sources comprise cosmic rays, terrestrial gamma rays, radionuclides in food and inhaled isotopes of radon with their decay products. These deliver doses to all organs and tissues including red bone marrow (RBM), the tissue in which leukaemia is thought to originate. In this paper we calculate the age-dependent annual RBM doses from natural radiation sources to young people and to adults at average levels of exposure in the UK. The contributions to dose are generally less complex than in the case of doses to foetuses and young children where it is necessary to take into account transfer of radionuclides across the placenta, intakes in mother's milk and changes in gut uptake in young infants. However, there is high uptake of alkaline earths and of similar elements in the developing skeleton and this significantly affects the doses from radioisotopes of these elements, not just in the teens and twenties but through into the fifth decade of life. The total equivalent dose to the RBM from all natural sources of radiation at age 15 years is calculated to be about 1200 {mu}Sv a year at average UK levels, falling to rather less than 1100 {mu}Sv per year in later life; the gentle fall from the late teens onwards reflects the diminishing effect of the high uptakes of radioisotopes of the alkaline earths and of lead in this period. About 60% of the equivalent dose is contributed by the low linear energy transfer (LET) component. Radionuclides in food make the largest contribution to equivalent doses to RBM and much the largest contribution to the absorbed dose from high LET radiation (mainly alpha particles).

Radiation doses at high altitudes and during space flights

International Nuclear Information System (INIS)

Spurny, F.

2001-01-01

There are three main sources of radiation exposure during space flights and at high altitudes--galactic cosmic radiation, solar cosmic radiation and radiation of the earth's radiation belt. Their basic characteristics are presented in the first part of this paper.Man's exposure during space flights is discussed in the second part of the paper. Particular attention is devoted to the quantitative and qualitative characteristics of the radiation exposure on near-earth orbits: both theoretical estimation as well as experimental data are presented. Some remarks on radiation protection rules on-board space vehicles are also given.The problems connected with the radiation protection of air crew and passengers of subsonic and supersonic air transport are discussed in the last part of the paper. General characteristics of on-board radiation fields and their variations with flight altitude, geomagnetic parameters of a flight and the solar activity are presented, both based on theoretical estimates and experimental studies. The questions concerning air crew and passenger radiation protection arising after the publication of ICRP 60 recommendation are also discussed. Activities of different institutions relevant to the topic are mentioned; strategies to manage and check this type of radiation exposure are presented and discussed. Examples of results based on the author's personal experience are given, analyzed and discussed. (author)

Construction of radioelement and dose rate baseline maps by combining ground and airborne radiometric data

International Nuclear Information System (INIS)

Rybach, L.; Medici, F.; Schwarz, G.F.

1997-01-01

For emergency situations like nuclear accidents, lost isotopic sources, debris of reactor-powered satellites etc. well-documented baseline information is indispensable. Maps of cosmic, terrestrial natural and artificial radiation can be constructed by assembling different datasets such as ground and airborne gamma spectrometry, direct dose rate measurements, and soil/rock samples. The in situ measurements were calibrated using the soil samples taken at/around the field measurement sites, the airborne measurements by a combination of in situ, and soil/rock sample data. The radioelement concentrations (Bq/kg) were in turn converted to dose-rate (nSv/h). First, the cosmic radiation map was constructed from a digital terrain model, averaging topographic heights within cells of 2 km X 2 km size. For the terrestrial radiation a total of 1615 ground data points were available, in addition to the airborne data. The artificial radiation map (Chernobyl and earlier fallout) has the smallest data base (184 data points from airborne and ground measurements). The dose rate map was constructed by summing up the above-mentioned contributions. It relies on a data base which corresponds to a density of about 1 point per 25 km 2 . The cosmic radiation map shows elevated dose rates in the high parts of the Swiss Alps. The cosmic dose rate ranges from 40 to 190 nSv/h, depending on altitude. The terrestrial dose rate maps show general agreement with lithology: elevated dose rates (100 to 200 nSv/h) characterize the Central Massifs of the Alps where crystalline rocks give a maximum of 370 nSv/h, whereas the sedimentary northern Alpine Foreland (Jura, Molasse basin) shows consistently lower dose rates (40-100 nSv/h). The artificial radiation map has its maximum value in the southern part of Switzerland (90 nSv/h). The map of total dose rate exhibits values from 55 to 570 nSv/h. These values are considerably higher than reported in the Radiation Atlas (''Natural Sources of Ionising

Department of Cosmic Radiation Physics: Overview

International Nuclear Information System (INIS)

Szabelski, J.

2000-01-01

Full text: Department of Cosmic Ray Physics in Lodz is involved in basic research in the area of high-energy physics and cosmic ray physics related to: -Studies of asymptotic properties of hadronic interactions based on the analysis of cosmic ray propagation through the atmosphere. -Experimental and phenomenological studies of Extensive Air Showers induced by cosmic ray particles. - Search for high-energy cosmic ray point sources. - Studies of cosmic ray propagation in the Galaxy and particle acceleration mechanisms. -Studies of mass composition of cosmic rays in the energy range 10 15 -10 17 eV. Theoretical and experimental studies of Extensive Air Shower properties are performed mainly on the basis of the results obtained by the Lodz Extensive Air Shower Array. We have analysed nearly 100,000 events of energies above 10 15 eV registered in the Lodz hodoscope. We have developed a method to verify different models of cosmic ray mass composition. The Lodz group collaborates with many foreign institutes and laboratories in construction and data interpretation of cosmic ray experiments. Our most important partners are: Forschungszentrum in Karlsruhe (Germany), College de France, Institute for Nuclear Studies of the Russian Academy of Sciences and Uppsala University (Sweden). (author)

Department of Cosmic Radiation Physics: Overview

International Nuclear Information System (INIS)

Gawin, J.

1998-01-01

(full text) The Department of Cosmic Ray Physics in Lodz is involved in basic research in the area of high energy physics and cosmic ray physics related to: -Studies of asymptotic properties of hadronic interactions based on the analysis of cosmic ray propagation in the atmosphere. -Studies of the structure and properties of Extensive Air Showers induced by cosmic ray particles. - Search for point sources of high energy cosmic rays. - Studies of cosmic ray propagation in the Galaxy and mechanisms of particle acceleration. - Studies of mass composition of cosmic rays in the energy range l0 15 -10 17 eV. Theoretical and experimental studies of nuclear interactions for energies exceeding those obtained by modern particle accelerators are performed based on the results obtained by the Lodz Extensive Air Shower Array. The Lodz hodoscope can register the electromagnetic component of cosmic ray showers developing in the atmosphere as well as muons of two energy thresholds. Data collected by the Lodz array are also used to study the mass composition of cosmic rays in the energy range 10 15 -10 17 eV. The Lodz group collaborates with many foreign institutes and laboratories in construction and data interpretation of cosmic ray experiments. Our most important partners are: Forschungszentrum Karlsruhe (Germany), College de' France, the Institute for Nuclear Studies of the Russian Academy of Science, the University of Perpignan (France) and Uppsala University (Sweden). (author)

ESR dating of elephant teeth and radiation dose rate estimation in soil

International Nuclear Information System (INIS)

Taisoo Chong; Ohta, Hiroyuki; Nakashima, Yoshiyuki; Iida, Takao; Saisho, Hideo

1989-01-01

Chemical analysis of 238 U, 232 Th and 40 K in the dentine as well as enamel of elephant tooth fossil has been carried out in order to estimate the internal absorbed dose rate of the specimens, which was estimated to be (39±4) mrad/y on the assumption of early uptake model of radionuclides. The external radiation dose rate in the soil including the contribution from cosmic rays was also estimated to be (175±18) mrad/y with the help of γ-ray spectroscopic techniques of the soil samples in which the specimens were buried. The 60 Co γ-ray equivalent accumulated dose of (2±0.2) x 10 4 rad for the tooth enamel gave ''ESR age'' of (9±2) x 10 4 y, which falls in the geologically estimated range between 3 x 10 4 and 30 x 10 4 y before the present. (author)

Evaluation of Differences in Response of DOD Portable Instruments and Solid-State Detectors used by MEXT for Measurement of External Radiations with Attention to the Cosmic Radiation Component

Science.gov (United States)

2014-03-01

Defense Threat Reduction Agency 8725 John J. Kingman Road, MS-6201 Fort Belvoir, VA 22060-6201...Attention to the Cosmic Radiation Component DISTRIBUTION A. Approved for public release: distribution is unlimited March 2014...Portable Instruments and Solid-State Detectors used by MEXT for Measurement of External Radiations with Attention to the Cosmic Radiation Component 5a

Shielding from cosmic radiation for interplanetary missions Active and passive methods

CERN Document Server

Spillantini, P; Durante, M; Müller-Mellin, R; Reitz, G; Rossi, L; Shurshakov, V; Sorbi, M

2007-01-01

Shielding is arguably the main countermeasure for the exposure to cosmic radiation during interplanetary exploratory missions. However, shielding of cosmic rays, both of galactic or solar origin, is problematic, because of the high energy of the charged particles involved and the nuclear fragmentation occurring in shielding materials. Although computer codes can predict the shield performance in space, there is a lack of biological and physical measurements to benchmark the codes. An attractive alternative to passive, bulk material shielding is the use of electromagnetic fields to deflect the charged particles from the spacecraft target. Active shielding concepts based on electrostatic fields, plasma, or magnetic fields have been proposed in the past years, and should be revised based on recent technological improvements. To address these issues, the European Space Agency (ESA) established a Topical Team (TT) in 2002 including European experts in the field of space radiation shielding and superconducting magn...

Biological impact of high-dose and dose-rate radiation exposure

International Nuclear Information System (INIS)

Maliev, V.; Popov, D.; Jones, J.; Gonda, S.; Prasad, K.; Viliam, C.; Haase, G.; Kirchin, V.; Rachael, C.

2006-01-01

Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

Biological impact of high-dose and dose-rate radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Maliev, V.; Popov, D. [Russian Academy of Science, Vladicaucas (Russian Federation); Jones, J.; Gonda, S. [NASA -Johnson Space Center, Houston (United States); Prasad, K.; Viliam, C.; Haase, G. [Antioxida nt Research Institute, Premier Micronutrient Corporation, Novato (United States); Kirchin, V. [Moscow State Veterinary and Biotechnology Acade my, Moscow (Russian Federation); Rachael, C. [University Space Research Association, Colorado (United States)

2006-07-01

Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

Radiation research contracts: Biological effects of small radiation doses

Energy Technology Data Exchange (ETDEWEB)

Hug, O [International Atomic Energy Agency, Division of Health, Safety and Waste Disposal, Vienna (Austria)

1959-04-15

To establish the maximum permissible radiation doses for occupational and other kinds of radiation exposure, it is necessary to know those biological effects which can be produced by very small radiation doses. This particular field of radiation biology has not yet been sufficiently explored. This holds true for possible delayed damage after occupational radiation exposure over a period of many years as well as for acute reactions of the organism to single low level exposures. We know that irradiation of less than 25 Roentgen units (r) is unlikely to produce symptoms of radiation sickness. We have, however, found indications that even smaller doses may produce certain instantaneous reactions which must not be neglected

Propagation of Polarized Cosmic Microwave Background Radiation in an Anisotropic Magnetized Plasma

International Nuclear Information System (INIS)

Moskaliuk, S. S.

2010-01-01

The polarization plane of the cosmic microwave background radiation (CMBR) can be rotated either in a space-time with metric of anisotropic type and in a magnetized plasma or in the presence of a quintessential background with pseudoscalar coupling to electromagnetism. A unified treatment of these three phenomena is presented for cold anisotropic plasma at the pre-recombination epoch. It is argued that the generalized expressions derived in the present study may be relevant for direct searches of a possible rotation of the cosmic microwave background polarization.

Modelling of the dose-rate variations with depth in the Martian regolith using GEANT4

International Nuclear Information System (INIS)

Morthekai, P.; Jain, M.; Dartnell, L.; Murray, A.S.; Botter-Jensen, L.; Desorgher, L.

2007-01-01

The environmental radiation field at the Martian surface consists mainly of Galactic Cosmic Rays (GCR) and charged particles ejected during the Solar Particle Events (SPE). Interactions between these radiation fluxes and the regolith result in a complex radiation field that varies both as a function of depth and time and can only be quantified using radiation transport models. We first describe here the main issues and constraints in deriving Martian dose rates. Preliminary results, obtained using the GEANT4 Monte Carlo simulation tool kit, suggest the surface dose rate is ∼63 mGy a -1 during quiet periods in solar activity. The accuracy of the model predictions has been tested by comparison with published observations of cosmic ray dose-rate variation in the Earth's atmosphere

Effects of small radiation doses

International Nuclear Information System (INIS)

Fuchs, G.

1986-01-01

The term 'small radiation dosis' means doses of about (1 rem), fractions of one rem as well as doses of a few rem. Doses like these are encountered in various practical fields, e.g. in X-ray diagnosis, in the environment and in radiation protection rules. The knowledge about small doses is derived from the same two forces, on which the radiobiology of human beings nearly is based: interpretation of the Hiroshima and Nagasaki data, as well as the experience from radiotherapy. Careful interpretation of Hiroshima dates do not provide any evidence that small doses can induce cancer, fetal malformations or genetic damage. Yet in radiotherapy of various diseases, e.g. inflammations, doses of about 1 Gy (100 rad) do no harm to the patients. According to a widespread hypothesis even very small doses may induce some types of radiation damage ('no threshold'). Nevertheless an alternative view is justified. At present no decision can be made between these two alternatives, but the usefullness of radiology is definitely better established than any damage calculated by theories or extrapolations. Based on experience any exaggerated fear of radiations can be met. (author)

Estimated radiation exposure of German commercial airline cabin crew in the years 1960-2003 modeled using dose registry data for 2004-2015.

Science.gov (United States)

Wollschläger, Daniel; Hammer, Gaël Paul; Schafft, Thomas; Dreger, Steffen; Blettner, Maria; Zeeb, Hajo

2018-05-01

Exposure to ionizing radiation of cosmic origin is an occupational risk factor in commercial aircrew. In a historic cohort of 26,774 German aircrew, radiation exposure was previously estimated only for cockpit crew using a job-exposure matrix (JEM). Here, a new method for retrospectively estimating cabin crew dose is developed. The German Federal Radiation Registry (SSR) documents individual monthly effective doses for all aircrew. SSR-provided doses on 12,941 aircrew from 2004 to 2015 were used to model cabin crew dose as a function of age, sex, job category, solar activity, and male pilots' dose; the mean annual effective dose was 2.25 mSv (range 0.01-6.39 mSv). In addition to an inverse association with solar activity, exposure followed age- and sex-dependent patterns related to individual career development and life phases. JEM-derived annual cockpit crew doses agreed with SSR-provided doses for 2004 (correlation 0.90, 0.40 mSv root mean squared error), while the estimated average annual effective dose for cabin crew had a prediction error of 0.16 mSv, equaling 7.2% of average annual dose. Past average annual cabin crew dose can be modeled by exploiting systematic external influences as well as individual behavioral determinants of radiation exposure, thereby enabling future dose-response analyses of the full aircrew cohort including measurement error information.

Radiation dose during angiographic procedures

International Nuclear Information System (INIS)

Lavoie, Ch.; Rasuli, P.

2001-01-01

The use of angiographic procedures is becoming more prevalent as new techniques and equipment are developed. There have been concerns in the scientific community about the level of radiation doses received by patients, and indirectly by staff, during some of these radiological procedures. The purpose of this study was to assess the level of radiation dose from angiographic procedures to patient at the Ottawa Hospital, General Campus. Radiation dose measurements, using Thermo-Luminescent Dosimeters (TLDs), were performed on more than 100 patients on various procedures. The results show that while the patient dose from the great majority of angiographic procedures is less than 2 Gy, a significant number of procedures, especially interventional procedures may have doses greater than 2 Gy and may lead to deterministic effects. (author)

Evaluation of fading factor and self-dose for glass dosimeter and thermoluminescence dosimeter

International Nuclear Information System (INIS)

Yamasaki, T.; Yamanishi, H.; Miyake, H.; Komura, K.

2000-01-01

The glass dosimeter (GD) and thermoluminescence dosimeter (TLD) are both passive radiation detectors. They are often used for measuring environmental radiation. In order to measure low dose rate preciously, it is important to evaluate decreased dose due to fading and self-dose during the exposure period. We evaluate the fading factor and self-dose of thee passive detectors, GD and TLD. We select Ogoya tunnel for the experiment. The tunnel is suitable field for measuring faded dose and self-dose because it is low cosmic radiation. At the center of the tunnel, the intensity of cosmic ray is reduced to about 1/177 than the outside of the funnel. We prepared two sets of dosimeters. One set consists of five GDs, five TLDs and some pre-irradiated GDs and TLDs that are exposed to standard radiation of 4 mGy by Cs-137. These dosimeters are put in the 10 cm thick lead box in order to shield the terrestrial gamma ray. One set is located at the center of the tunnel and the other is the outside of the funnel. The dosimeters were exposed for ten months, from May 1998 to March 1999. After the exposure, the readers of dosimeters are carried into the funnel to read out the signals promptly as soon as taking out the dosimeters. As a result of the measurement, four kinds of data are taken for GD and TLD respectively. Assumed that the self-dose and cosmic ray are constant during exposure, the four independent unknown quantities, a self-dose a dose due to cosmic ray and a fading coefficient at the center of the tunnel and at the outside, are considered. Therefore four simultaneous equations should be obtained. From these examinations, the faded dose of GD is less than 1%, but that of TLD is about 16% during ten months. The coefficient for compensation of fading of GD and TLD is given as the half of the each value. At the outside of the tunnel, the measured dose rate of cosmic ray that can pass through the 10 cm lead is evaluated to be about 16 nGy/h by both detectors. The self-dose

Radiation dose in vertebroplasty

International Nuclear Information System (INIS)

Mehdizade, A.; Lovblad, K.O.; Wilhelm, K.E.; Somon, T.; Wetzel, S.G.; Kelekis, A.D.; Yilmaz, H.; Abdo, G.; Martin, J.B.; Viera, J.M.; Ruefenacht, D.A.

2004-01-01

We wished to measure the absorbed radiation dose during fluoroscopically controlled vertebroplasty and to assess the possibility of deterministic radiation effects to the operator. The dose was measured in 11 consecutive procedures using thermoluminescent ring dosimeters on the hand of the operator and electronic dosimeters inside and outside of the operator's lead apron. We found doses of 0.022-3.256 mGy outside and 0.01-0.47 mGy inside the lead apron. Doses on the hand were higher, 0.5-8.5 mGy. This preliminary study indicates greater exposure to the operator's hands than expected from traditional apron measurements. (orig.)

Radiation dose-reduction strategies in thoracic CT.

Science.gov (United States)

Moser, J B; Sheard, S L; Edyvean, S; Vlahos, I

2017-05-01

Modern computed tomography (CT) machines have the capability to perform thoracic CT for a range of clinical indications at increasingly low radiation doses. This article reviews several factors, both technical and patient-related, that can affect radiation dose and discusses current dose-reduction methods relevant to thoracic imaging through a review of current techniques in CT acquisition and image reconstruction. The fine balance between low radiation dose and high image quality is considered throughout, with an emphasis on obtaining diagnostic quality imaging at the lowest achievable radiation dose. The risks of excessive radiation dose reduction are also considered. Inappropriately low dose may result in suboptimal or non-diagnostic imaging that may reduce diagnostic confidence, impair diagnosis, or result in repeat examinations incurring incremental ionising radiation exposure. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Are low radiation doses Dangerous?

International Nuclear Information System (INIS)

Garcia Lima, O.; Cornejo, N.

1996-01-01

In the last few years the answers to this questions has been affirmative as well as negative from a radiation protection point of view low doses of ionizing radiation potentially constitute an agent causing stochasting effects. A lineal relation without threshold is assumed between dose and probability of occurrence of these effects . Arguments against the danger of probability of occurrence of these effects. Arguments again the danger of low dose radiation are reflected in concepts such as Hormesis and adaptive response, which are phenomena that being studied at present

Analysis of CT radiation dose based on radiation-dose-structured reports

International Nuclear Information System (INIS)

Wang Weipeng; Zhang Yi; Zhang Menglong; Zhang Dapeng; Song Shaojuan

2014-01-01

Objective: To analyse the CT radiation dose statistically using the standardized radiation-dose-structured report (RDSR) of digital imaging and communications in medicine (DICOM). Methods: Using the self-designed software, 1230 RDSR files about CT examination were obtained searching on the picture archiving and communication system (PACS). The patient dose database was established by combination of the extracted relevant information with the scanned sites. The patients were divided into adult group (over 10 years) and child groups (0-1 year, 1-5 years, 5-10 years) according to the age. The average volume CT dose index (CTDI vol ) and dose length product (DLP) of all scans were recorded respectively, and then the effective dose (E) was estimated. The DLP value at 75% quantile was calculated and compared with the diagnostic reference level (DRL). Results: In adult group, CTDI vol and DLP values were moderately and positively correlated (r = 0.41), the highest E was observed in upper abdominal enhanced scan, and the DLP value at 75% quantile was 60% higher than DRL. In child group, their CTDI vol in group of 5-10 years was greater than that in groups of 0-1 and 1-5 years (t = 2.42, 2.04, P < 0.05); the DLP value was slightly and positively correlated with the age (r = 0.16), while E was moderately and negatively correlated with the age (r = -0.48). Conclusions: It is a simple and efficient method to use RDSR to obtain the radiation doses of patients. With the popularization of the new equipment and the application of regionalized medical platform, RDSR would become the main tool for the dosimetric level surveying and individual dose recording. (authors)

Radiation production and absorption in human spacecraft shielding systems under high charge and energy Galactic Cosmic Rays: Material medium, shielding depth, and byproduct aspects

Science.gov (United States)

Barthel, Joseph; Sarigul-Klijn, Nesrin

2018-03-01

Deep space missions such as the planned 2025 mission to asteroids require spacecraft shields to protect electronics and humans from adverse effects caused by the space radiation environment, primarily Galactic Cosmic Rays. This paper first reviews the theory on how these rays of charged particles interact with matter, and then presents a simulation for a 500 day Mars flyby mission using a deterministic based computer code. High density polyethylene and aluminum shielding materials at a solar minimum are considered. Plots of effective dose with varying shield depth, charged particle flux, and dose in silicon and human tissue behind shielding are presented.

''Low dose'' and/or ''high dose'' in radiation protection: A need to setting criteria for dose classification

International Nuclear Information System (INIS)

Sohrabi, M.

1997-01-01

The ''low dose'' and/or ''high dose'' of ionizing radiation are common terms widely used in radiation applications, radiation protection and radiobiology, and natural radiation environment. Reading the title, the papers of this interesting and highly important conference and the related literature, one can simply raise the question; ''What are the levels and/or criteria for defining a low dose or a high dose of ionizing radiation?''. This is due to the fact that the criteria for these terms and for dose levels between these two extreme quantities have not yet been set, so that the terms relatively lower doses or higher doses are usually applied. Therefore, setting criteria for classification of radiation doses in the above mentioned areas seems a vital need. The author while realizing the existing problems to achieve this important task, has made efforts in this paper to justify this need and has proposed some criteria, in particular for the classification of natural radiation areas, based on a system of dose limitation. (author)

Estimated neutron dose to embryo and foetus during commercial flight

International Nuclear Information System (INIS)

Chen, J.; Lewis, B. J.; Bennett, L. G. I.; Green, A. R.; Tracy, B. L.

2005-01-01

A study has been carried out to assess the radiation exposure from cosmic-ray neutrons to the embryo and foetus of pregnant aircrew and air travellers in consideration of the radiation exposure from cosmic-ray neutrons to the embryo and foetus. A Monte Carlo analysis was performed to determine the equivalent dose from neutrons to the brain and body of an embryo at 8 weeks and to the foetus at the 3, 6 and 9 month periods. Neutron fluence-to-absorbed dose conversion coefficients for the foetal brain and for the entire foetal body (isotropic irradiation geometry) have been determined at the four developmental stages. The equivalent dose rate to the foetus during commercial flights has been further evaluated considering the fluence-to-absorbed dose conversion coefficients, a neutron spectrum measured at an altitude of 11.3 km and an ICRP-92 radiation-weighting factor for neutrons. This study indicates that the foetus can exceed the annual dose limit of 1 mSv for the general public after, for example, 15 round trips on commercial trans-Atlantic flights. (authors)

Exposure of the Spanish population to radiation from natural sources

International Nuclear Information System (INIS)

Garcia-Talavera, M.; Suarez, E.; Matarranz, J.L.; Salas, R.; Ramos, L.

2006-01-01

We have assessed the exposure of the Spanish population to natural radiation sources. The annual average effective dose is estimated to be 2.38 mSv, taking into account contributions from cosmic radiation (13.8%), terrestrial gamma radiation (39%), radon and thoron inhalation (34%) and ingestion (13.2%). Cosmic radiation doses were calculated from town altitude data. Terrestrial gamma ray exposure outdoors was derived from the M.A.R.N.A. (natural gamma radiation map of Spain). Indoor gamma ray exposure was calculated by multiplying the corresponding outdoor value by a conversion factor, which was obtained by a linear least-squares fit of experimental measurements. Radon doses were estimated from national surveys carried out throughout the country. To assess doses by ingestion of water and foodstuffs we considered the results from a detailed study on consumption habits by age and geographical area in Spain, promoted by C.S.N., and average radioactivity values from UNSCEAR. (authors)

Exposure of the Spanish population to radiation from natural sources

Energy Technology Data Exchange (ETDEWEB)

Garcia-Talavera, M.; Suarez, E.; Matarranz, J.L.; Salas, R.; Ramos, L. [Consejo de Seguridad Nuclear. Justo Dorado, Madrid (Spain)

2006-07-01

We have assessed the exposure of the Spanish population to natural radiation sources. The annual average effective dose is estimated to be 2.38 mSv, taking into account contributions from cosmic radiation (13.8%), terrestrial gamma radiation (39%), radon and thoron inhalation (34%) and ingestion (13.2%). Cosmic radiation doses were calculated from town altitude data. Terrestrial gamma ray exposure outdoors was derived from the M.A.R.N.A. (natural gamma radiation map of Spain). Indoor gamma ray exposure was calculated by multiplying the corresponding outdoor value conversion factor, which was obtained by a linear least-squares fit of experimental measurements. Radon doses were estimated from national surveys carried out throughout the country. To assess doses by ingestion of water and foodstuffs we considered the results from a detailed study on consumption habits by age and geographical area in Spain, promoted by C.S.N., and average radioactivity values from UNSCEAR. (authors)

Do dose area product meter measurements reflect radiation doses ...

African Journals Online (AJOL)

Enrique

SA JOURNAL OF RADIOLOGY • August 2004. Abstract. This study determined the correlation between radiation doses absorbed by health care workers and dose area product meter (DAP) measurements at Universitas Hospital, Bloemfontein. The DAP is an instrument which accurately measures the radiation emitted from ...

Do dose area product meter measurements reflect radiation doses ...

African Journals Online (AJOL)

This study determined the correlation between radiation doses absorbed by health care workers and dose area product meter (DAP) measurements at Universitas Hospital, Bloemfontein. The DAP is an instrument which accurately measures the radiation emitted from the source. The study included the interventional ...

Distortions in the Rayleigh-Jeans region of the cosmic background radiation spectrum

International Nuclear Information System (INIS)

De Zotti, G.

1982-01-01

The theory of the origin and evolution of distortions in the Rayleigh-Jeans region of the cosmic background radiation spectrum is reviewed. Some proposed experiments, designed to substantially improve our knowledge of that portion of the spectrum, are briefly described. (author)

KERMA-based radiation dose management system for real-time patient dose measurement

Science.gov (United States)

Kim, Kyo-Tae; Heo, Ye-Ji; Oh, Kyung-Min; Nam, Sang-Hee; Kang, Sang-Sik; Park, Ji-Koon; Song, Yong-Keun; Park, Sung-Kwang

2016-07-01

Because systems that reduce radiation exposure during diagnostic procedures must be developed, significant time and financial resources have been invested in constructing radiation dose management systems. In the present study, the characteristics of an existing ionization-based system were compared to those of a system based on the kinetic energy released per unit mass (KERMA). Furthermore, the feasibility of using the KERMA-based system for patient radiation dose management was verified. The ionization-based system corrected the effects resulting from radiation parameter perturbations in general radiography whereas the KERMA-based system did not. Because of this difference, the KERMA-based radiation dose management system might overestimate the patient's radiation dose due to changes in the radiation conditions. Therefore, if a correction factor describing the correlation between the systems is applied to resolve this issue, then a radiation dose management system can be developed that will enable real-time measurement of the patient's radiation exposure and acquisition of diagnostic images.

Measurement of the cosmic background radiation temperature at 6.3 cm

International Nuclear Information System (INIS)

Mandolesi, N.; Calzolari, P.; Cortiglioni, S.; Morigi, G.

1984-01-01

We present results of a measurement of the cosmic background radiation temperature at a wavelength of 6.3 cm. We obtained the value T/sub CBR/ = 2.71 +- 0.20 K. This is in good agreement with, and has a smaller error than, any previous measurement at equal or longer wavelengths

Dose limits for cosmic radiation during space flights

International Nuclear Information System (INIS)

Draaisma, F.S.

1991-01-01

Astronauts are exposed to raised levels of ionizing radiation, which may cause biologic effects during space flights. Insights in these effects should lead to doselimits for astronauts during their full career. (author). 4 refs.; 4 tabs

Living with radiation

International Nuclear Information System (INIS)

Tymen, G.

1999-01-01

This editorial article discusses the various forms of radiation that we live with. In particular, the general public's lack of knowledge on the subject is mentioned and the concentration of the media on radiation accidents and emissions is looked at critically. The various forms of radiation - ionising and non-ionising - are briefly discussed. Natural ionising radiation sources and in particular radon are described and the increasing proportion of doses attributed to cosmic radiation met in high-flying aircraft and radiation doses resulting from medical examination and treatment are discussed. Non-ionising radiation such as electromagnetic fields generated by power lines, mobile telephones and kitchen equipment and their implications on health are also looked at

Cosmic radiation dosimetry in international flights argentine airlines

International Nuclear Information System (INIS)

Ciancio, Vicente R.; Oliveri, Pedro V.; Di Giovan B, Gustavo; Ciancio, Vanina L.; Lewis, Brent J.; Green, Anna R.; Bennet, L.

2008-01-01

Full text: Introduction: In commercial aviation the most important determinants of radiation exposure in humans are the altitude, latitude, flight duration and the solar cycle's period. This study was conducted to address this type of exposure trough radiation dosimetry. Method: The study was performed in the business-class cabin of an Airbus 340-200 aircraft, provided by Argentine Airlines, during 2 flights routes: New York-Miami-Buenos Aires (trans equatorial) and Buenos Aires-Auckland (circumpolar). Measurements addressed the electromagnetic spectrum or low Linear Energy Transfer (LET) and corpuscular radiation (High LET). The instruments used were an Ion Chamber (IC), to measure the ionizing component of radiation (i.e., gamma radiation), the SWENDI, to measure only the neutron component, and the Tissue Equivalent Proportional Counter (TEPC) for measuring all radiation types. Results: The routes' dose rates are presented in the table. TEPC rates agreed with the LET findings. The total dose rates of high latitude flights were higher than those of low latitude flights. The SWENDI (High LET) results for the flights over the equator, at low latitude, represented only 1/3 of the total radiation. The New York-Miami and Buenos Aires-Auckland flights, at high latitude, represented just under 1/2 of the Total radiation (-45%). Conclusion: Based on the results of this study, the annual dose rates of radiation exposure of air crew personnel serving on international flights offered by Argentine Airlines is between 3 and 7 mSv. This rate is higher than the maximum recommended for the general population by the International Commission on Radiological Protection (ICRP), which is 1 milli Sv./y. Therefore, these personnel must be officially considered 'Occupationally Exposed to Radiation' in way to provide the appropriate measures that must be implemented for their protection in accordance to ICRP guidelines. Dose(uSv): Route N Y-Miami, IC 6.07, SWENDI 5.07, TEPC 11.04; Route

Numerical investigations of radiation exposure in civil aviation

International Nuclear Information System (INIS)

Beck, P.; Felsberger, E.; O'Brien, K.; Kindl, P.

1998-01-01

Previous in-flight measurements of radiation exposure to air crews is compared with calculations by cosmic ray transport codes. Primary cosmic ray particle spectra modifications by solar modulation and by the geomagnetic field are discussed. The cosmic ray propagation and behaviour in the atmosphere is described by the Boltzmann equation. Results of calculations are shown in graphical form, including the altitude dependence of the effective dose rate at various geomagnetic latitudes, the effect of the 11-year solar modulation cycle, and 3 world maps of effective dose rates at usual flight altitudes. (A.K.)

Health effect of low dose/low dose rate radiation

International Nuclear Information System (INIS)

Kodama, Seiji

2012-01-01

The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

Radiation absorbed doses in cephalography

International Nuclear Information System (INIS)

Eliasson, S.; Julin, P.; Richter, S.; Stenstroem, B.

1984-01-01

Radiation absorbed doses to different organs in the head and neck region in lateral (LAT) and postero-anterior (PA) cephalography were investigated. The doses were measured by thermoluminescence dosimeters (TLD) on a tissue equivalent phantom head. Lanthanide screens in speed group 4 were used at 90 and 85 k Vp. A near-focus aluminium dodger was used and the radiation beam was collimated strictly to the face. The maximum entrance dose from LAT was 0.25 mGy and 0.42 mGy from a PA exposure. The doses to the salivary glands ranged between 0.2 and 0.02 mGy at LAT and between 0.15 and 0.04 mGy at PA exposures. The average thyroid gland dose without any shielding was 0.11 mGy (LAT) and 0.06 mGy (PA). When a dodger was used the dose was reduced to 0.07 mGy (LAT). If the thyroid gland was sheilded off, the dose was further reduced to 0.01 mGy and if the thyroid region was collimated out of the primary radiation field the dose was reduced to only 0.005 mGy. (authors)

High energy radiation from black holes gamma rays, cosmic rays, and neutrinos

CERN Document Server

Dermer, Charles D

2009-01-01

Bright gamma-ray flares observed from sources far beyond our Milky Way Galaxy are best explained if enormous amounts of energy are liberated by black holes. The highest- energy particles in nature--the ultra-high-energy cosmic rays--cannot be confined by the Milky Way's magnetic field, and must originate from sources outside our Galaxy. Understanding these energetic radiations requires an extensive theoretical framework involving the radiation physics and strong-field gravity of black holes. In High Energy Radiation from Black Holes, Charles Dermer and Govind Menon present a systemat

Radiation dose estimates for radiopharmaceuticals

International Nuclear Information System (INIS)

Stabin, M.G.; Stubbs, J.B.; Toohey, R.E.

1996-04-01

Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms

Some characteristics and effects of natural radiation

International Nuclear Information System (INIS)

Mc Laughlin, J.P.

2015-01-01

Since life first appeared on the Earth, it has, in all its subsequent evolved forms including human, been exposed to natural radiation in the environment both from terrestrial and extra-terrestrial sources. Being an environmental mutagen, ionising natural radiation may have played a role of some significance in the evolution of early life forms on Earth. It has been estimated by United Nations Scientific Committee on the Effects of Atomic Radiation that at the present time, exposure to natural radiation globally results in an annual average individual effective dose of about 2.4 mSv. This represents about 80 % of the total dose from all sources. The three most important components of natural radiation exposure are cosmic radiation, terrestrial radioactivity and indoor radon. Each of these components exhibits both geographical and temporal variabilities with indoor radon exposure being the most variable and also the largest contributor to dose for most people. In this account, an overview is given of the characteristics of the main components of the natural radiation environment and some of their effects on humans. In the case of cosmic radiation, these range from radiation doses to aircrew and astronauts to the controversial topic of its possible effect on climate change. In the case of terrestrial natural radiation, accounts are given of a number of human exposure scenarios. (author)

Cytogenetic effects of low-dose radiation

International Nuclear Information System (INIS)

Metalli, P.

1983-01-01

The effects of ionizing radiation on chromosomes have been known for several decades and dose-effect relationships are also fairly well established in the mid- and high-dose and dose-rate range for chromosomes of mammalian cells. In the range of low doses and dose rates of different types of radiation few data are available for direct analysis of the dose-effect relationships, and extrapolation from high to low doses is still the unavoidable approach in many cases of interest for risk assessment. A review is presented of the data actually available and of the attempts that have been made to obtain possible generalizations. Attention is focused on some specific chromosomal anomalies experimentally induced by radiation (such as reciprocal translocations and aneuploidies in germinal cells) and on their relevance for the human situation. (author)

Validation of radiation dose estimations in VRdose: comparing estimated radiation doses with observed radiation doses

International Nuclear Information System (INIS)

Nystad, Espen; Sebok, Angelia; Meyer, Geir

2004-04-01

The Halden Virtual Reality Centre has developed work-planning software that predicts the radiation exposure of workers in contaminated areas. To validate the accuracy of the predicted radiation dosages, it is necessary to compare predicted doses to actual dosages. During an experimental study conducted at the Halden Boiling Water Reactor (HBWR) hall, the radiation exposure was measured for all participants throughout the test session, ref. HWR-681 [3]. Data from this experimental study have also been used to model tasks in the work-planning software and gather data for predicted radiation exposure. Two different methods were used to predict radiation dosages; one method used all radiation data from all the floor levels in the HBWR (all-data method). The other used only data from the floor level where the task was conducted (isolated data method). The study showed that the all-data method gave predictions that were on average 2.3 times higher than the actual radiation dosages. The isolated-data method gave predictions on average 0.9 times the actual dosages. (Author)

Generation of terrestrial radiation database in the Larsemann Hills, Antarctica

International Nuclear Information System (INIS)

Pal, Rupali; Dhabekar, Bhushan; Jose, Jis Romal; Chinnaesakki, S.; Bakshi, A.K.; Datta, D.; Pradeepkumar, K.S.

2018-01-01

Natural background radiation in the environment includes terrestrial radiation, cosmic radiation from space and air activity due to radon/thoron. It is known that cosmic contribution increases near the poles. The terrestrial component is largely due to 232 Th and 238 U series and 40 K. BARC under the cosmic ray dosimetry project with National Centre for Antarctic and Ocean Research (NCAOR) has taken up measurement of natural background radiation at Larsemann Hills, Antarctica. The project includes generation of baseline data on terrestrial radioactivity in water, soil and rock and estimation of cosmic ray doses. Extensive radiation surveys were carried out by the BARC team in the 35 th and 36 th expedition in and around Larsemann hills in East Antarctica where the third Indian station 'Bharati' is situated. This paper presents mapping of terrestrial radiation levels in Antarctica which will help in strengthening the background radiation database and develop a Radiation Informatics System (RIS)

Natural environmental radioactivity with particular regard to radon gas and cosmic radiation

International Nuclear Information System (INIS)

Lowder, W.M.

1993-01-01

A paper given at the previous workshop described the growth of our knowledge of the nature and sources of human exposure to naturally-occurring radiation and radionuclides, and summarized assessments of the individual components of this exposure. Here, some recent developments relevant to the earlier conclusions are described, and a closer look is taken at the increasingly important human exposure contribution of cosmic radiation, especially at aircraft altitudes. (author). 21 refs, 1 tab

Prenatal radiation doses from radiopharmaceuticals

International Nuclear Information System (INIS)

Rojo, A.M.; Gomez Parada, I.M.; Di Trano, J.L.

1998-01-01

The radiopharmaceutical administration with diagnostic or therapeutic purpose during pregnancy implies a prenatal radiation dose. The dose assessment and the evaluation of the radiological risks become relevant due to the great radiosensitivity of the fetal tissues in development. This paper is a revision of the available data for estimating fetal doses in the cases of the more frequently used radiopharmaceuticals in nuclear medicine, taking into account recent investigation in placental crossover. The more frequent diagnostic and therapeutic procedures were analyzed according to the radiation doses implied. (author) [es

Comparison of CREME (cosmic-ray effects on microelectronics) model LET (linear energy transfer) spaceflight dosimetry data

Energy Technology Data Exchange (ETDEWEB)

Letaw, J.R.; Adams, J.H.

1986-07-15

The galactic cosmic radiation (GCR) component of space radiation is the dominant cause of single-event phenomena in microelectronic circuits when Earth's magnetic shielding is low. Spaceflights outside the magnetosphere and in high inclination orbits are examples of such circumstances. In high-inclination orbits, low-energy (high LET) particles are transmitted through the field only at extreme latitudes, but can dominate the orbit-averaged dose. GCR is an important part of the radiation dose to astronauts under the same conditions. As a test of the CREME environmental model and particle transport codes used to estimate single event upsets, we have compiled existing measurements of HZE doses were compiled where GCR is expected to be important: Apollo 16 and 17, Skylab, Apollo Soyuz Test Project, and Kosmos 782. The LET spectra, due to direct ionization from GCR, for each of these missions has been estimated. The resulting comparisons with data validate the CREME model predictions of high-LET galactic cosmic-ray fluxes to within a factor of two. Some systematic differences between the model and data are identified.

Doses from radiation exposure

International Nuclear Information System (INIS)

Menzel, H-G.; Harrison, J.D.

2012-01-01

Practical implementation of the International Commission on Radiological Protection’s (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP’s 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effective dose. In preparation for the calculation of new dose coefficients, Committee 2 and its task groups have provided updated nuclear decay data (ICRP Publication 107) and adult reference computational phantoms (ICRP Publication 110). New dose coefficients for external exposures of workers are complete (ICRP Publication 116), and work is in progress on a series of reports on internal dose coefficients to workers from inhaled and ingested radionuclides. Reference phantoms for children will also be provided and used in the calculation of dose coefficients for public exposures. Committee 2 also has task groups on exposures to radiation in space and on the use of effective dose.

Determination of the radiation dose to the body due to external radiation

International Nuclear Information System (INIS)

Drexler, G.; Eckerl, H.

1985-01-01

Section 63 of the Radiation Protection Ordinance defines the basic requirement, determination of radiation dose to the body. The determination of dose equivalents for the body is the basic step in practical monitoring of dose equivalents or dose limits with regard to individuals or population groups, both for constant or varying conditions of exposure. The main field of monitoring activities is the protection of persons occupationally exposed to ionizing radiation. Conversion factors between body doses and radiation quantities are explained. (DG) [de

Cosmic Microwave Background Timeline

Science.gov (United States)

Cosmic Microwave Background Timeline 1934 : Richard Tolman shows that blackbody radiation in an will have a blackbody cosmic microwave background with temperature about 5 K 1955: Tigran Shmaonov anisotropy in the cosmic microwave background, this strongly supports the big bang model with gravitational

Effects of low dose radiation and epigenetic regulation

International Nuclear Information System (INIS)

Jiao Benzheng; Ma Shumei; Yi Heqing; Kong Dejuan; Zhao Guangtong; Gao Lin; Liu Xiaodong

2010-01-01

Purpose: To conclude the relationship between epigenetics regulation and radiation responses, especially in low-dose area. Methods: The literature was examined for papers related to the topics of DNA methylation, histone modifications, chromatin remodeling and non-coding RNA modulation in low-dose radiation responses. Results: DNA methylation and radiation can regulate reciprocally, especially in low-dose radiation responses. The relationship between histone methylation and radiation mainly exists in the high-dose radiation area; histone deacetylase (HDAC) inhibitors show a promising application to enhance radiation sensitivity, no matter whether in low-dose or high-dose areas; the connection between γ-H2AX and LDR has been remained unknown, although γ-H2AX has been shown no radiation sensitivities with 1-15 Gy irradiation; histone ubiquitination play an important role in DNA damage repair mechanism. Moreover, chromatin remodeling has an integral role in DSB repair and the chromatin response, in general, may be precede DNA end resection. Finally, the effect of radiation on miRNA expression seems to vary according to cell type, radiation dose, and post-irradiation time point. Conclusion: Although the advance of epigenetic regulation on radiation responses, which we are managing to elucidate in this review, has been concluded, there are many questions and blind blots deserved to investigated, especially in low-dose radiation area. However, as progress on epigenetics, we believe that many new elements will be identified in the low-dose radiation responses which may put new sights into the mechanisms of radiation responses and radiotherapy. (authors)

Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice

International Nuclear Information System (INIS)

Ware, J.H.; Rusek, A.; Sanzari, J.; Avery, S.; Sayers, C.; Krigsfeld, G.; Nuth, M.; Wan, X.S.; Kennedy, A.R.

2010-01-01

The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice.

Science.gov (United States)

Ware, J H; Sanzari, J; Avery, S; Sayers, C; Krigsfeld, G; Nuth, M; Wan, X S; Rusek, A; Kennedy, A R

2010-09-01

The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

Doses due to extra-vehicular activity on space stations

Energy Technology Data Exchange (ETDEWEB)

Deme, S.; Apathy, I.; Feher, I. [KFKI Atomic Energy Research Institute, Budapest (Hungary); Akatov, Y.; Arkhanguelski, V. [Institute of Biomedical Problems, State Scientific Center, Moscow (Russian Federation); Reitz, G. [DLR Institute of Aerospace Medicine, Cologne, Linder Hohe (Germany)

2006-07-01

One of the many risks of long duration space flight is the dose from cosmic radiation, especially during periods of intensive solar activity. At such times, particularly during extra-vehicular activity (E.V.A.), when the astronauts are not protected by the wall of the spacecraft, cosmic radiation is a potentially serious health threat. Accurate dose measurement becomes increasingly important during the assembly of large space objects. Passive integrating detector systems such as thermoluminescent dosimeters (TLDs) are commonly used for dosimetric mapping and personal dosimetry on space vehicles. K.F.K.I. Atomic Energy Research Institute has developed and manufactured a series of thermoluminescent dosimeter systems, called Pille, for measuring cosmic radiation doses in the 3 {mu}Gy to 10 Gy range, consisting of a set of CaSO{sub 4}:Dy bulb dosimeters and a small, compact, TLD reader suitable for on-board evaluation of the dosimeters. Such a system offers a solution for E.V.A. dosimetry as well. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations, on the Space Shuttle, and most recently on several segments of the International Space Station (I.S.S.). The Pille system was used to make the first measurements of the radiation exposure of cosmonauts during E.V.A.. Such E.V.A. measurements were carried out twice (on June 12 and 16, 1987) by Y. Romanenko, the commander of the second crew of Mir. During the E.V.A. one of the dosimeters was fixed in a pocket on the outer surface of the left leg of his space-suit; a second dosimeter was located inside the station for reference measurements. The advanced TLD system Pille 96 was used during the Nasa-4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the exposure of two of the astronauts during their E.V.A. activities. The extra doses of two E.V.A. during the Euromir 95 and one E.V.A. during the Nasa4 experiment

Doses due to extra-vehicular activity on space stations

International Nuclear Information System (INIS)

Deme, S.; Apathy, I.; Feher, I.; Akatov, Y.; Arkhanguelski, V.; Reitz, G.

2006-01-01

One of the many risks of long duration space flight is the dose from cosmic radiation, especially during periods of intensive solar activity. At such times, particularly during extra-vehicular activity (E.V.A.), when the astronauts are not protected by the wall of the spacecraft, cosmic radiation is a potentially serious health threat. Accurate dose measurement becomes increasingly important during the assembly of large space objects. Passive integrating detector systems such as thermoluminescent dosimeters (TLDs) are commonly used for dosimetric mapping and personal dosimetry on space vehicles. K.F.K.I. Atomic Energy Research Institute has developed and manufactured a series of thermoluminescent dosimeter systems, called Pille, for measuring cosmic radiation doses in the 3 μGy to 10 Gy range, consisting of a set of CaSO 4 :Dy bulb dosimeters and a small, compact, TLD reader suitable for on-board evaluation of the dosimeters. Such a system offers a solution for E.V.A. dosimetry as well. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations, on the Space Shuttle, and most recently on several segments of the International Space Station (I.S.S.). The Pille system was used to make the first measurements of the radiation exposure of cosmonauts during E.V.A.. Such E.V.A. measurements were carried out twice (on June 12 and 16, 1987) by Y. Romanenko, the commander of the second crew of Mir. During the E.V.A. one of the dosimeters was fixed in a pocket on the outer surface of the left leg of his space-suit; a second dosimeter was located inside the station for reference measurements. The advanced TLD system Pille 96 was used during the Nasa-4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the exposure of two of the astronauts during their E.V.A. activities. The extra doses of two E.V.A. during the Euromir 95 and one E.V.A. during the Nasa4 experiment were

Dose specification for radiation therapy: dose to water or dose to medium?

International Nuclear Information System (INIS)

Ma, C-M; Li Jinsheng

2011-01-01

The Monte Carlo method enables accurate dose calculation for radiation therapy treatment planning and has been implemented in some commercial treatment planning systems. Unlike conventional dose calculation algorithms that provide patient dose information in terms of dose to water with variable electron density, the Monte Carlo method calculates the energy deposition in different media and expresses dose to a medium. This paper discusses the differences in dose calculated using water with different electron densities and that calculated for different biological media and the clinical issues on dose specification including dose prescription and plan evaluation using dose to water and dose to medium. We will demonstrate that conventional photon dose calculation algorithms compute doses similar to those simulated by Monte Carlo using water with different electron densities, which are close (<4% differences) to doses to media but significantly different (up to 11%) from doses to water converted from doses to media following American Association of Physicists in Medicine (AAPM) Task Group 105 recommendations. Our results suggest that for consistency with previous radiation therapy experience Monte Carlo photon algorithms report dose to medium for radiotherapy dose prescription, treatment plan evaluation and treatment outcome analysis.

Estimation of radiation dose received by the radiation workers during radiographic testing

International Nuclear Information System (INIS)

Mohammed, N. A. H. O.

2013-08-01

This study was conducted primarily to evaluate occupational radiation dose in industrial radiography during radiographic testing at Balil-Hadida, with the aim of building up baseline data on radiation exposure in the industrial radiography practice in Sudan. Dose measurements during radiographic testing were performed and compared with IAEA reference dose. In this research the doses measured by using hand held radiation survey meter and personal monitoring dosimeter. The results showed that radiation doses ranged between minimum (0.448 mSv/ 3 month) , and maximum (1.838 mSv / 3 month), with an average value (0.778 mSv/ 3 month), and the standard deviation 0.292 for the workers used gamma mat camera. The analysis of data showed that the radiation dose for all radiation worker are receives less than annual limit for exposed workers 20 mSv/ year and compare with other study found that the dose received while body doses ranging from 0.1 to 9.4 mSv/ year, work area design in all the radiography site followed the three standard rules namely putting radiation signs, reducing access to control area and making of boundaries. Thus the accidents arising from design faults not likely to occur at these site. Results suggest that adequate fundamental training of radiation workers in general radiography prior to industrial radiography work will further improve the standard of personnel radiation protection. (Author)

Characteristics of radiation field in living environment, 2

International Nuclear Information System (INIS)

Nagaoka, Toshi; Sakamoto, Ryuichi; Tsutsumi, Masahiro; Saito, Kimiaki; Moriuchi, Shigeru

1990-01-01

A series of environmental radiation survey was carried out on train lines within Tokyo metropolitan area to clarify the characteristics of radiation field in living environment. Eleven JR, 18 private and 10 subway lines were surveyed, which cover 97% of whole train lines in Tokyo district in terms of annual number of passengers. The characteristics of environmental radiation field on train lines were discussed. The mean absorbed dose rate in air due to γ-rays on the subway lines was higher than those on the JR and private lines. It is due to the difference in the radioactivity concentration and the distribution of surrounding materials as the γ-ray sources. On the other hand, the mean dose rate due to cosmic-rays on the subway lines was lower than those on the JR and private lines. It is due to the shielding effect of the upper materials such as soil or building materials of tunnels. The mean dose rates for the JR, private and subway lines were calculated using these obtained data. Though the ratio of mean dose rate of γ-rays to that of cosmic-rays for the subway lines was different from those for the JR and private lines, the sum of γ- and cosmic-ray dose rates for the JR, private and subway lines were comparable, 40∼50 nGy/h for any of them. These data will be useful for a precise and realistic evaluation of collective dose, considering the life style of the public and the variation characteristics of environmental radiation. (author)

Radiation in the Einstein universe and the cosmic background

International Nuclear Information System (INIS)

Segal, I.E.

1983-01-01

It is shown that the cosmic background radiation is not at all uniquely or scientifically relatively economically indicative of a ''big bang.'' Specifically, essentially any temporally homogeneous theory in the Einstein universe is consistent with the existence of a cosmic background radiation (CBR) conforming to the Planck law; in particular, the chronometric cosmology is such. It is noted that the Einstein universe appears particularly natural as a habitat for photons by virtue of the absence of infrared divergences and of the absolute convergence of the trace for associated Gibbs-state density matrices. These features are connected with the closed character of space in the Einstein universe, and facilitate the use of the latter in modeling local phenomena, in place of Minkowski space with periodic boundary conditions or the like, with minimal loss of covariance or effect on the wave functions. In particular, the Einstein universe may be used in the analysis of the perturbation of a Planck-law spectrum due to a local nonvanishing isotropic angular momentum of the CBR, of whatever origin. The estimated distortion of the spectrum due to such a kinematically admissible effect is in very good agreement with that observed by Woody and Richards, which is opposite in direction to those earlier predicted by big-bang theories. The theoretical analysis involves a preliminary treatment of equilibria of linear quantum fields with supplementary quasilinear constraints

CRaTER: The Cosmic Ray Telescope for the Effects of Radiation Experiment on the Lunar Reconnaissance Orbiter Mission

OpenAIRE

Spence, H. E.; Case, A. W.; Golightly, M. J.; Heine, T.; Larsen, B. A.; Blake, J. B.; Caranza, P.; Crain, W. R.; George, J.; Lalic, M.; Lin, A.; Looper, M. D.; Mazur, J. E.; Salvaggio, D.; Kasper, J. C.

2009-01-01

The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) characterizes the radiation environment to be experienced by humans during future lunar missions. CRaTER measures the effects of ionizing energy loss in matter due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCR), specifically in silicon solid-state detectors and after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaT...

The evaluation and use of a portable TEPC system for measuring in-flight exposure to cosmic radiation

Energy Technology Data Exchange (ETDEWEB)

Taylor, G.C.; Bentley, R.D.; Conroy, T.J.; Hunter, R.; Jones, J.B.L.; Pond, A.; Thomas, D.J

2002-07-01

A recent EC directive has called for all member states to introduce legislation covering the assessment and restriction of air crew exposure to cosmic radiation. In the UK the Civil Aviation Authority, in conjunction with the Department of the Environment, Transport and the Regions issued guidelines suggesting the use of a predictive code such as CARI for this purpose. In order to validate the use of calculated route doses, an extensive programme of measurements is being carried out in conjunction with Virgin Atlantic Airways, using a prototype HAWK TEPC developed by Far West Technology. This programme began in January 2000 and by the end of February 2001 had resulted in the accumulation of data from 74 flights. In this paper the instrument design is discussed, together with the calibration program. An overview of the in-flight results is also presented, including comparisons between measurements and calculations, which indicates that CARI under-predicts the route doses by approximately 20%. (author)

The evaluation and use of a portable TEPC system for measuring in-flight exposure to cosmic radiation

International Nuclear Information System (INIS)

Taylor, G.C.; Bentley, R.D.; Conroy, T.J.; Hunter, R.; Jones, J.B.L.; Pond, A.; Thomas, D.J.

2002-01-01

A recent EC directive has called for all member states to introduce legislation covering the assessment and restriction of air crew exposure to cosmic radiation. In the UK the Civil Aviation Authority, in conjunction with the Department of the Environment, Transport and the Regions issued guidelines suggesting the use of a predictive code such as CARI for this purpose. In order to validate the use of calculated route doses, an extensive programme of measurements is being carried out in conjunction with Virgin Atlantic Airways, using a prototype HAWK TEPC developed by Far West Technology. This programme began in January 2000 and by the end of February 2001 had resulted in the accumulation of data from 74 flights. In this paper the instrument design is discussed, together with the calibration program. An overview of the in-flight results is also presented, including comparisons between measurements and calculations, which indicates that CARI under-predicts the route doses by approximately 20%. (author)

CALIBRATION OF MODIFIED LIULIN DETECTOR FOR COSMIC RADIATION MEASUREMENTS ON-BOARD AIRCRAFT

Czech Academy of Sciences Publication Activity Database

Kyselová, Dagmar; Ambrožová, Iva; Krist, Pavel; Kubančák, Ján; Uchihori, Y.; Kitamura, H.; Ploc, Ondřej

2015-01-01

Roč. 164, č. 4 (2015), s. 489-492 ISSN 0144-8420 R&D Projects: GA MŠk(CZ) LG13031 Institutional support: RVO:61389005 Keywords : Liulin detector * on-board aircraft * cosmic radiation measurement Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.894, year: 2015

Real-Time Aircraft Cosmic Ray Radiation Exposure Predictions from the NAIRAS Model

Science.gov (United States)

Mertens, C. J.; Tobiska, W.; Kress, B. T.; Xu, X.

2012-12-01

The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. There is also interest in extending NAIRAS to the LEO environment to address radiation hazard issues for the emerging commercial spaceflight industry. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. Real-time observations are required at a variety of locations within the geospace environment. The NAIRAS model is driven by real-time input data from ground-, atmospheric-, and space-based platforms. During the development of the NAIRAS model, new science questions and observational data gaps were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. The focus of this talk is to present the current capabilities of the NAIRAS model, discuss future developments in aviation radiation modeling and instrumentation, and propose strategies and methodologies of bridging known gaps in current modeling and observational capabilities.

Risk of radiation-induced cancer at low doses and low dose rates for radiation protection purposes

International Nuclear Information System (INIS)

1995-01-01

The aim of this report is to provide an updated, comprehensive review of the data available for assessing the risk of radiation-induced cancer for radiation protection purposes. Particular emphasis is placed on assessing risks at low doses and low dose rates. The review brings together the results of epidemiological investigations and fundamental studies on the molecular and cellular mechanisms involved in radiation damage. Additionally, this information is supplemented by studies with experimental animals which provide further guidance on the form of the dose-response relationship for cancer induction, as well as on the effect of dose rate on the tumour yield. The emphasis of the report is on cancer induction resulting from exposure to radiations with a low linear energy transfer (LET). The work was performed under contract for the Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses, Paris, France, whose agreement to publish is gratefully ackowledged. It extends the advice on radiation risks given in Documents of the NRPB, 4 No. 4 (1993). (Author)

Occupational radiation doses during interventional procedures

International Nuclear Information System (INIS)

Nuraeni, N; Hiswara, E; Kartikasari, D; Waris, A; Haryanto, F

2016-01-01

Digital subtraction angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. The use of DSA procedures has been increased quite significantly in the Radiology departments in various cities in Indonesia. Various reports showed that both patients and medical staff received a noticeable radiation dose during the course of this procedure. A study had been carried out to measure these doses among interventionalist, nurse and radiographer. The results show that the interventionalist and the nurse, who stood quite close to the X-ray beams compared with the radiographer, received radiation higher than the others. The results also showed that the radiation dose received by medical staff were var depending upon the duration and their position against the X-ray beams. Compared tothe dose limits, however, the radiation dose received by all these three medical staff were still lower than the limits. (paper)

Low doses of gamma radiation in soybean

International Nuclear Information System (INIS)

Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C.; Arthur, Valter; Arthur, Paula B.; Franco, Caio H.

2017-01-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Low doses of gamma radiation in soybean

Energy Technology Data Exchange (ETDEWEB)

Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C., E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio H. [Universidade Federal de São Paulo (UNIFESP), SP (Brazil). Departamento de Microbiologia, Imunologia e Parasitologia

2017-07-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Natural terrestrial radiation exposure in Hong Kong. A survey on environmental gamma absorbed dose rate in air

International Nuclear Information System (INIS)

Wong, M.C.; Poon, H.T.; Chan, Y.K.; So, C.K.

2000-01-01

Hong Kong is a metropolitan city located on the southern coast of China with a population of some six million. About 90% of the population is concentrated in heavily built-up residential and commercial areas, which accounts for less than 50% of the total area in the territory. Hong Kong Observatory, 134A Nathan Road, Kowloon, Hong Kong, China. In order to understand the spatial variations in the environmental radiation levels in Hong Kong, the Hong Kong Observatory (HKO) in early 1999 conducted a study of the environmental gamma absorbed dose rate in air. The study combined data collected by the HKO radiation monitoring network (RMN) and data from a comprehensive territory-wide radiological survey conducted in January and February 1999. The RMN of ten stations each equipped with a Reuter-Stokes Model RSS-1013 HPIC has been in operation since 1987 to continuously monitor the environmental radiation levels over the territory as part of the emergency monitoring programme for response to nuclear accidents at a nearby nuclear power station. The terrestrial component of the environmental radiation field was estimated by subtracting from the measurements the cosmic contribution, which is determined to be about 39 nGy/h from measurements conducted over two large fresh water reservoirs. The RMN data with the long history was analysed to derive the seasonal variations in the environmental radiation levels. On average the environmental gamma absorbed dose rate in air in January and February is 1.03 times of the annual figure. This seasonal correction was applied to the results of the year 1999 survey. As the radiation field in the heavily built-up areas is enhanced by contribution from buildings, in the territory-wide survey measurements were made both in the open field and built-up areas. The territory of Hong Kong was divided into 42 grid boxes of 5 km x 5 km for open field and 61 grid boxes of 2.5 km x 2.5 km for built-up areas according to the population and land use. A

Track-etched detectors for the dosimetry of the radiation of cosmic origin

International Nuclear Information System (INIS)

Spurny, F.; Turek, K.

2004-01-01

Cosmic rays contribute to the exposure on the Earth's surface as well as in its surroundings. At the surface and/or at aviation altitudes, there are mostly secondary particles created through the cosmic rays interaction in the atmosphere, which contribute to this type of exposure. Onboard a spacecraft, the exposure comes mostly from primary cosmic rays. Track-etched detectors (TED) are able to characterise both these types of exposure. The contribution of neutrons, of cosmic origin, on the Earth's surface was studied at altitudes from few hundreds to 3000 m using TED in a moderator sphere. The results obtained are compared with other data on this type of natural radiation background. The results of studies performed onboard aircraft and/or spacecraft are presented afterwards. We used TED-based neutron dosemeter, as well as a spectrometer of linear energy transfer based on a chemically etched TED. The results of studies performed onboard aircraft, as well as spacecraft, are presented and discussed, including an attempt to estimate a neutron component onboard the spacecraft. It was found that they correlate with the results of other independent investigations. (authors)

Radiation exposure profile and dose estimates to flyers en route Frankfurt to Mumbai

International Nuclear Information System (INIS)

Rao, D.D.; Hegde, A.G.

2010-01-01

The earth is continuously bombarded by the high energy radiation (galactic radiation) from solar system commonly known as cosmic radiation. Intensity of cosmic ray radiation exposures change with altitude and increases rapidly with the increase in altitude from the earth. Passenger and cargo flights fly at different altitudes and therefore the crew and passengers are exposed to radiation levels significantly higher than the average background levels on the earth. A typical commercial jet aircraft fly at an altitude of 30,000 - 40,000 feet (9-12 km) and at these heights radiation exposure rates increase by about 100 times from the background levels. European countries have guidelines and suggestions on radiation exposure to air crew members in sectors that may potentially expose them to levels exceeding 1 mSv per annum. The paper details the radiation exposure profile recorded in Frankfurt-Dubai-Mumbai sector and evaluation of average radiation exposure received by the flyers and air crew members

New limits to the small scale fluctuations in the cosmic background radiation

International Nuclear Information System (INIS)

Kellermann, K.I.; Fomalont, E.B.; Wall, J.V.

1983-01-01

The VLA has been used at 4.9 GHz to observe a small region of sky in order to extend the radio source count to low flux density (Fomalont et al., these proceedings) and to look for small scale fluctuations in the 2.7 K cosmic microwave background radiation. (Auth.)

Cosmic radiation exposure of aircraft crew: compilation of measured and calculated data

Czech Academy of Sciences Publication Activity Database

Lindborg, L.; Bartlett, D.; Beck, P.; McAulay, I.; Schnuer, K.; Schraube, H.; Spurný, František

2004-01-01

Roč. 110, 1-4 (2004), s. 417-422 ISSN 0144-8420 Grant - others:EC project(XE) FIGM-CT2000-00068 Institutional research plan: CEZ:AV0Z1048901 Keywords : cosmic radiation exposure * aircraft crew * measurement Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.617, year: 2003

Total dose and dose rate radiation characterization of EPI-CMOS radiation hardened memory and microprocessor devices

International Nuclear Information System (INIS)

Gingerich, B.L.; Hermsen, J.M.; Lee, J.C.; Schroeder, J.E.

1984-01-01

The process, circuit discription, and total dose radiation characteristics are presented for two second generation hardened 4K EPI-CMOS RAMs and a first generation 80C85 microprocessor. Total dose radiation performance is presented to 10M rad-Si and effects of biasing and operating conditions are discussed. The dose rate sensitivity of the 4K RAMs is also presented along with single event upset (SEU) test data

Effective dose: a radiation protection quantity

CERN Document Server

Menzel, H G

2012-01-01

Modern radiation protection is based on the principles of justification, limitation, and optimisation. Assessment of radiation risks for individuals or groups of individuals is, however, not a primary objective of radiological protection. The implementation of the principles of limitation and optimisation requires an appropriate quantification of radiation exposure. The International Commission on Radiological Protection (ICRP) has introduced effective dose as the principal radiological protection quantity to be used for setting and controlling dose limits for stochastic effects in the regulatory context, and for the practical implementation of the optimisation principle. Effective dose is the tissue weighted sum of radiation weighted organ and tissue doses of a reference person from exposure to external irradiations and internal emitters. The specific normalised values of tissue weighting factors are defined by ICRP for individual tissues, and used as an approximate age- and sex-averaged representation of th...

Doses from Medical Radiation Sources

Science.gov (United States)

... Medical Radiation Sources Michael G. Stabin, PhD, CHP Introduction Radiation exposures from diagnostic medical examinations are generally ... of exposure annually to natural background radiation. Plain Film X Rays Single Radiographs Effective Dose, mSv Skull ( ...

Cosmic ray LET spectra and doses on board Cosmos-2044 biosatellite

International Nuclear Information System (INIS)

Dudkin, V.E.; Kovalev, E.E.; Potapov, Yu.V.

1992-01-01

Results of the experiments on board Cosmos-2044 (Biosatellite 9) are presented. Various nuclear track detectors (NTD) (dielectric, AgCl-based, nuclear emulsions) were used to obtain the LET spectra inside and outside the satellite. The spectra from the different NTDs have proved to be in general agreement. The results of LET spectra calculations using two different models are also presented. The resultant LET distributions are used to calculate the absorbed and equivalent doses and the orbit-averaged quality factors (QF) of the cosmic rays (CR). Absorbed dose rates inside (∼ 20 g cm -2 shielding) and outside (1 g cm -2 ) the spacecraft, omitting electrons, were found to be 4.8 and 8.6 mrad d -1 , respectively, while the corresponding equivalent doses were 8.8 and 19.7 mrem d -1 . The effects of the flight parameters on the total fluence of, and on the dose from, the CR particles are analyzed. Integral dose distributions of the detected particles are also determined. The LET values which separate absorbed and equivalent doses into 50% intervals are estimated. The CR-39 dielectric NTD is shown to detect 20-30% of the absorbed dose and 60-70% of the equivalent dose in the Cosmos-2044 orbit. The influence of solar activity phase on the magnitude of the CR flux is discussed. (author)

A Paradigm Shift in Low Dose Radiation Biology

Directory of Open Access Journals (Sweden)

Z. Alatas

2015-08-01

Full Text Available When ionizing radiation traverses biological material, some energy depositions occur and ionize directly deoxyribonucleic acid (DNA molecules, the critical target. A classical paradigm in radiobiology is that the deposition of energy in the cell nucleus and the resulting damage to DNA are responsible for the detrimental biological effects of radiation. It is presumed that no radiation effect would be expected in cells that receive no direct radiation exposure through nucleus. The risks of exposure to low dose ionizing radiation are estimated by extrapolating from data obtained after exposure to high dose radiation. However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose radiation than they do to high dose radiation. Moreover, recent experimental evidences from many laboratories reveal the fact that radiation effects also occur in cells that were not exposed to radiation and in the progeny of irradiated cells at delayed times after radiation exposure where cells do not encounter direct DNA damage. Recently, the classical paradigm in radiobiology has been shifted from the nucleus, specifically the DNA, as the principal target for the biological effects of radiation to cells. The universality of target theory has been challenged by phenomena of radiation-induced genomic instability, bystander effect and adaptive response. The new radiation biology paradigm would cover both targeted and non-targeted effects of ionizing radiation. The mechanisms underlying these responses involve biochemical/molecular signals that respond to targeted and non-targeted events. These results brought in understanding that the biological response to low dose radiation at tissue or organism level is a complex process of integrated response of cellular targets as well as extra-cellular factors. Biological understanding of

Energies, health, medicine. Low radiation doses

International Nuclear Information System (INIS)

2004-01-01

This file concerns the biological radiation effects with a special mention for low radiation doses. The situation of knowledge in this area and the mechanisms of carcinogenesis are detailed, the different directions of researches are given. The radiation doses coming from medical examinations are given and compared with natural radioactivity. It constitutes a state of the situation on ionizing radiations, known effects, levels, natural radioactivity and the case of radon, medicine with diagnosis and radiotherapy. (N.C.)

Studying the high energy cosmic radiation: contributions to its detection and to the exploration of its origin

International Nuclear Information System (INIS)

Lamanna, Giovanni

2009-01-01

The Astro-particle Physics is a discipline where scientists from both the astrophysics and the particle physics communities meets to investigate the Universe aiming to answer to fundamental questions in the field of physics, cosmology and astrophysics. The high energy astrophysics domain, which explores the extremes sources where the larger collective transfer of energy take place, studies the most energetic cosmic radiation as privileged messengers of the history of the Universe. My research path, summarized in this work, is made of personal contributions in the development of new detection technologies, in the data analysis, perspectives and phenomenological studies about the scientific purposes of large experiments: e.g. AMS, ANTARES, HESS, CTA, POLAR. My contributions are the results of research activities in coherence with two main scientific goals in the context of the astro-particle physics domain: - The implication of the high energy cosmic radiation measurement for the investigation on the nature and distribution of the dark matter; - The investigation of the origin of the galactic cosmic radiation for the understanding of the most energetic processes in the Universe. (author)

High-dose preoperative radiation for cancer of the rectum: Impact of radiation dose on patterns of failure and survival

International Nuclear Information System (INIS)

Ahmad, N.R.; Mohiuddin, M.; Marks, G.

1993-01-01

A variety of dose-time schedules are currently used for preoperative radiation therapy of rectal cancer. An analysis of patients treated with high-dose preoperative radiation therapy was undertaken to determine the influence of radiation dose on the patterns of failure, survival, and complications. Two hundred seventy-five patients with localized rectal cancer were treated with high-dose preoperative radiation therapy. One hundred fifty-six patients received 45 Gy (low-dose group). Since 1985, 119 patients with clinically unfavorable cancers were given a higher dose, 55 Gy using a shrinking field technique (high-dose group). All patients underwent curative resection. Median follow-up was 66 months in the low-dose group and 28 months in the high-dose group. Patterns of failure, survival, and complications were analyzed as a function of radiation dose. Fourteen percent of the total group developed a local recurrence; 20% in the low-dose group as compared with 6% in the high-dose group. The actuarial local recurrence rate at 5 years was 20% for the low-dose group and 8% for the high-dose group, and approached statistical significance with p = .057. For tethered/fixed tumors the actuarial local recurrence rates at 5 years were 28% and 9%, respectively, with p = .05. Similarly, for low-lying tumors (less than 6 cm from the anorectal junction) the rates were 24% and 9%, respectively, with p = .04. The actuarial rate of distant metastasis was 28% in the low-dose group and 20% in the high-dose group and was not significantly different. Overall actuarial 5-year survival for the total group of patients was 66%. No significant difference in survival was observed between the two groups, despite the higher proportion of unfavorable cancers in the high-dose group. The incidence of complications was 2%, equally distributed between the two groups. High-dose preoperative radiation therapy for rectal cancer results in excellent local control rates. 27 refs., 2 figs., 8 tabs

Biological effects of single HZE-particles of the cosmic radiation: Free Flyer Biostack

International Nuclear Information System (INIS)

1989-01-01

The Free Flyer Biostack is designed as a passive, longer term experiment for investigations into the dosimetry of cosmic HZE particles (high-charge energetic particles), the effects of single HZE particles on isolated biological samples, and the synergistic effects of conditions in space, as e.g. zero gravity and presence of a permanent, weakly ionizing component of the cosmic radiation. For the experiments summarized in this project report, the AgCl detector type developed in Frankfurt has been used, consisting of monocrystalline AgCl films, about 130-150 μm thick, and doped with 5000 ppm of Cd. (DG) With 9 figs [de

Galactic cosmic ray simulation at the NASA Space Radiation Laboratory

Science.gov (United States)

Norbury, John W.; Schimmerling, Walter; Slaba, Tony C.; Azzam, Edouard I.; Badavi, Francis F.; Baiocco, Giorgio; Benton, Eric; Bindi, Veronica; Blakely, Eleanor A.; Blattnig, Steve R.; Boothman, David A.; Borak, Thomas B.; Britten, Richard A.; Curtis, Stan; Dingfelder, Michael; Durante, Marco; Dynan, William S.; Eisch, Amelia J.; Elgart, S. Robin; Goodhead, Dudley T.; Guida, Peter M.; Heilbronn, Lawrence H.; Hellweg, Christine E.; Huff, Janice L.; Kronenberg, Amy; La Tessa, Chiara; Lowenstein, Derek I.; Miller, Jack; Morita, Takashi; Narici, Livio; Nelson, Gregory A.; Norman, Ryan B.; Ottolenghi, Andrea; Patel, Zarana S.; Reitz, Guenther; Rusek, Adam; Schreurs, Ann-Sofie; Scott-Carnell, Lisa A.; Semones, Edward; Shay, Jerry W.; Shurshakov, Vyacheslav A.; Sihver, Lembit; Simonsen, Lisa C.; Story, Michael D.; Turker, Mitchell S.; Uchihori, Yukio; Williams, Jacqueline; Zeitlin, Cary J.

2017-01-01

Most accelerator-based space radiation experiments have been performed with single ion beams at fixed energies. However, the space radiation environment consists of a wide variety of ion species with a continuous range of energies. Due to recent developments in beam switching technology implemented at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL), it is now possible to rapidly switch ion species and energies, allowing for the possibility to more realistically simulate the actual radiation environment found in space. The present paper discusses a variety of issues related to implementation of galactic cosmic ray (GCR) simulation at NSRL, especially for experiments in radiobiology. Advantages and disadvantages of different approaches to developing a GCR simulator are presented. In addition, issues common to both GCR simulation and single beam experiments are compared to issues unique to GCR simulation studies. A set of conclusions is presented as well as a discussion of the technical implementation of GCR simulation. PMID:26948012

Investigation of radiation skin dose in interventional cardiology

International Nuclear Information System (INIS)

Webster, C.M.; Horrocks, J.; Hayes, D.

2001-01-01

Background - The study investigated the radiation skin doses for interventional patients in cardiology; two procedures which have the highest radiation dose are Radiofrequency Catheter Ablation (RFCA) and Percutaneous Transluminal Coronary Angioplasty (PTCA). Methods and Results - 56 patients were randomly selected and investigated; 23 patients in the RFCA group and 33 in the PTCA group. Skin and effective dose were calculated from Dose Area Product (DAP). Thermoluminescent Dosimetry was the second method of dose measurement used. Patients were followed-up for a three month period to check for possible skin reactions resulting from the radiation dose during the procedure. Radiation skin doses in 14 patients were calculated to be more than 1 Gy, including three patients who received more than 2 Gy, the threshold dose for deterministic effects of radiation. 7 patients (12.5%) reported skin reactions as a result of the radiation received to their backs during the procedure. Mean DAP and estimated effective doses were 105 Gycm 2 and 22.5 mSv for RFCA, and 32 Gycm 2 and 6.2 mSv for PTCA procedures respectively. Conclusion - Complex procedures in Interventional Cardiology can exceed the threshold level for deterministic effects in the skin. (author)

Cosmic rays, clouds, and climate

DEFF Research Database (Denmark)

Marsh, N.; Svensmark, Henrik

2000-01-01

cloud radiative properties. Thus, a moderate influence on atmospheric aerosol distributions from cosmic ray ionisation would have a strong influence on the Earth's radiation budget. Historical evidence over the past 1000 years indicates that changes in climate have occurred in accord with variability......A correlation between a global average of low cloud cover and the flux of cosmic rays incident in the atmosphere has been observed during the last solar cycle. The ionising potential of Earth bound cosmic rays are modulated by the state of the heliosphere, while clouds play an important role...... in the Earth's radiation budget through trapping outgoing radiation and reflecting incoming radiation. If a physical link between these two features can be established, it would provide a mechanism linking solar activity and Earth's climate. Recent satellite observations have further revealed a correlation...

Mars' surface radiation environment measured with the Mars science laboratory's curiosity rover

NARCIS (Netherlands)

Hassler, D.M.; Zeitlin, C.; Wimmer-Schweingruber, R.F.; Ehresmann, B.; Rafkin, S.; Eigenbrode, J.L.; Brinza, D.E.; Weigle, G.; Böttcher, S.; Böhm, E.; Burmeister, S.; Guo, J.; Köhler, J.; Martin, C.; Reitz, G.; Cucinotta, F.A.; Kim, M.-H.; Grinspoon, D.; Bullock, M.A.; Posner, A.; Gómez-Elvira, J.; Vasavada, A.; Grotzinger, J.P.; MSL Science Team, the|info:eu-repo/dai/nl/292012217

2014-01-01

The Radiation Assessment Detector (RAD) on the Mars Science Laboratory’s Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose

Transatlantic Comparison of CT Radiation Doses in the Era of Radiation Dose-Tracking Software.

Science.gov (United States)

Parakh, Anushri; Euler, Andre; Szucs-Farkas, Zsolt; Schindera, Sebastian T

2017-12-01

The purpose of this study is to compare diagnostic reference levels from a local European CT dose registry, using radiation-tracking software from a large patient sample, with preexisting European and North American diagnostic reference levels. Data (n = 43,761 CT scans obtained over the course of 2 years) for the European local CT dose registry were obtained from eight CT scanners at six institutions. Means, medians, and interquartile ranges of volumetric CT dose index (CTDI vol ), dose-length product (DLP), size-specific dose estimate, and effective dose values for CT examinations of the head, paranasal sinuses, thorax, pulmonary angiogram, abdomen-pelvis, renal-colic, thorax-abdomen-pelvis, and thoracoabdominal angiogram were obtained using radiation-tracking software. Metrics from this registry were compared with diagnostic reference levels from Canada and California (published in 2015), the American College of Radiology (ACR) dose index registry (2015), and national diagnostic reference levels from local CT dose registries in Switzerland (2010), the United Kingdom (2011), and Portugal (2015). Our local registry had a lower 75th percentile CTDI vol for all protocols than did the individual internationally sourced data. Compared with our study, the ACR dose index registry had higher 75th percentile CTDI vol values by 55% for head, 240% for thorax, 28% for abdomen-pelvis, 42% for thorax-abdomen-pelvis, 128% for pulmonary angiogram, 138% for renal-colic, and 58% for paranasal sinus studies. Our local registry had lower diagnostic reference level values than did existing European and North American diagnostic reference levels. Automated radiation-tracking software could be used to establish and update existing diagnostic reference levels because they are capable of analyzing large datasets meaningfully.

Radiation Dose Measurement Using Chemical Dosimeters

International Nuclear Information System (INIS)

Lee, Min Sun; Kim, Eun Hee; Kim, Yu Ri; Han, Bum Soo

2010-01-01

The radiation dose can be estimated in various ways. Dose estimates can be obtained by either experiment or theoretical analysis. In experiments, radiation impact is assessed by measuring any change caused by energy deposition to the exposed matter, in terms of energy state (physical change), chemical production (chemical change) or biological abnormality (biological change). The chemical dosimetry is based on the implication that the energy deposited to the matter can be inferred from the consequential change in chemical production. The chemical dosimetry usually works on the sample that is an aqueous solution, a biological matter, or an organic substance. In this study, we estimated absorbed doses by quantitating chemical changes in matter caused by radiation exposure. Two different chemical dosimeters, Fricke and ECB (Ethanol-Chlorobenzene) dosimeter, were compared in several features including efficacy as dose indicator and effective dose range

Prenatal radiation exposure. Dose calculation

International Nuclear Information System (INIS)

Scharwaechter, C.; Schwartz, C.A.; Haage, P.; Roeser, A.

2015-01-01

The unborn child requires special protection. In this context, the indication for an X-ray examination is to be checked critically. If thereupon radiation of the lower abdomen including the uterus cannot be avoided, the examination should be postponed until the end of pregnancy or alternative examination techniques should be considered. Under certain circumstances, either accidental or in unavoidable cases after a thorough risk assessment, radiation exposure of the unborn may take place. In some of these cases an expert radiation hygiene consultation may be required. This consultation should comprise the expected risks for the unborn while not perturbing the mother or the involved medical staff. For the risk assessment in case of an in-utero X-ray exposition deterministic damages with a defined threshold dose are distinguished from stochastic damages without a definable threshold dose. The occurrence of deterministic damages depends on the dose and the developmental stage of the unborn at the time of radiation. To calculate the risks of an in-utero radiation exposure a three-stage concept is commonly applied. Depending on the amount of radiation, the radiation dose is either estimated, roughly calculated using standard tables or, in critical cases, accurately calculated based on the individual event. The complexity of the calculation thereby increases from stage to stage. An estimation based on stage one is easily feasible whereas calculations based on stages two and especially three are more complex and often necessitate execution by specialists. This article demonstrates in detail the risks for the unborn child pertaining to its developmental phase and explains the three-stage concept as an evaluation scheme. It should be noted, that all risk estimations are subject to considerable uncertainties.

Radiation dose exposure in patients affected by lymphoma undergoing repeat CT examinations: how to manage the radiation dose variability.

Science.gov (United States)

Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Dore, Antonio; Aringhieri, Giacomo; Caramella, Davide

2018-03-01

To assess the variability of radiation dose exposure in patients affected by lymphoma undergoing repeat CT (computed tomography) examinations and to evaluate the influence of different scan parameters on the overall radiation dose. A series of 34 patients (12 men and 22 women with a median age of 34.4 years) with lymphoma, after the initial staging CT underwent repeat follow-up CT examinations. For each patient and each repeat examination, age, sex, use of AEC system (Automated Exposure Control, i.e. current modulation), scan length, kV value, number of acquired scans (i.e. number of phases), abdominal size diameter and dose length product (DLP) were recorded. The radiation dose of just one venous phase was singled out from the DLP of the entire examination. All scan data were retrieved by our PACS (Picture Archiving and Communication System) by means of a dose monitoring software. Among the variables we considered, no significant difference of radiation dose was observed among patients of different ages nor concerning tube voltage. On the contrary the dose delivered to the patients varied depending on sex, scan length and usage of AEC. No significant difference was observed depending on the behaviour of technologists, while radiologists' choices had indirectly an impact on the radiation dose due to the different number of scans requested by each of them. Our results demonstrate that patients affected by lymphoma who undergo repeat whole body CT scanning may receive unnecessary overexposure. We quantified and analyzed the most relevant variables in order to provide a useful tool to manage properly CT dose variability, estimating the amount of additional radiation dose for every single significant variable. Additional scans, incorrect scan length and incorrect usage of AEC system are the most relevant cause of patient radiation exposure.

Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu; Magae, Junji

2008-01-01

Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

Biological effects of low-dose ionizing radiation exposure

International Nuclear Information System (INIS)

Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

2009-01-01

The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

Personal radiation monitoring and assessment of doses received by radiation workers (1991)

International Nuclear Information System (INIS)

Morris, N.D.

1992-06-01

The Australian Radiation Laboratory has operated a Personal Radiation Monitoring Service since the early 1930's so that people working with radiation can determine the radiation doses that they receive due to their occupation. Since late 1986, all persons monitored by the Service have been registered on a data base which maintains records of the doses received by each individual wearer. Ultimately, this data base will become a National Register of the doses received within Australia. At present, the Service regularly monitors approximately 20,000 persons, which is roughly 70 percent of those monitored in Australia, and maintains dose histories of over 35,000 people. The skin dose for occupationally exposed workers can be measured by using one of the four types of monitor issued by the Service: 1. Thermoluminescent Dosemeter (TLD monitor) 2. Finger TLD 3. Neutron Monitor 4. Special TLD. The technical description of the monitors is provided along with the method for calculating the radiation dose. 5 refs., 7 tabs., 4 figs

Generalized Chaplygin gas and cosmic microwave background radiation constraints

International Nuclear Information System (INIS)

Bento, M.C.; Bertolami, O.; Sen, A.A.

2003-01-01

We study the dependence of the location of the cosmic microwave background radiation peaks on the parameters of the generalized Chaplygin gas model, whose equation of state is given by p=-A/ρ α , where A is a positive constant and 0<α≤1. We find, in particular, that observational data arising from Archeops, BOOMERANG, supernova and high-redshift observations allow constraining significantly the parameter space of the model. Our analysis indicates that the emerging model is clearly distinguishable from the α=1 Chaplygin case and the ΛCDM model

George Smoot, Blackbody, and Anisotropy of the Cosmic Microwave Background

Science.gov (United States)

the Cosmic Microwave Background Radiation Resources with Additional Information * Videos 'George Smoot anisotropy of the cosmic microwave background radiation." '1 Smoot previously won the Ernest Orlando . Smoot, blackbody, and anisotropy of the Cosmic Microwave Background (CMB) radiation is available in full

Spherical ionization chamber of 14 liter for precise measurement of environmental radiation dose rate

International Nuclear Information System (INIS)

Nagaoka, Toshi; Saito, Kimiaki; Moriuchi, Shigeru

1991-05-01

A spherical ionization chamber of 14 liter filled with 1 atm. nitrogen gas was arranged aiming at precise measurement of dose rate due to environmental gamma rays and cosmic rays. Ionization current-dose rate conversion factor for this ionization chamber was derived from careful consideration taking into account the attenuation by chamber wall, ionization current due to alpha particles and so on. Experiments at calibrated gamma ray fields and intercomparison with NaI(Tl) scintillation detector were also performed, which confirmed this ionization chamber using the conversion factor can measure the dose rate with an error of only a few percent. This ionization chamber will be used for measurement of environmental gamma ray and cosmic ray dose rate. (author)

Radiation dose to the patient in radionuclide studies

International Nuclear Information System (INIS)

Roedler, H.D.

1981-01-01

In medical radionuclide studies, the radiation risk has to be considered in addition to the general risk of administering a pharmaceutical. As radiation exposure is an essential factor in radiation risk estimation, some aspects of internal dose calculation, including radiation risk assessments, are treated. The formalism of current internal dose calculation is presented. The input data, especially the residence time and the absorbed dose per transformation, their origin and accuracy are discussed. Results of internal dose calculations for the ten most frequently used radionuclide studies are presented as somatically effective dose equivalents. The accuracy of internal dose calculation is treated in detail by considering the biokinetics of the radiopharmaceutical, the phantoms used for dose calculations, the absorbed dose per transformation, the administered activity, and the transfer of the dose, calculated for a phantom, to the patient. The internal dose calculated for a reference phantom may be assumed to be in accordance with the actual patient dose within a range described by a factor of about two to three. Finally, risk estimates for nuclear medicine procedures are quantified, being generally of sixth order. The radiation risk from the radioiodine test is comparably higher, but probably lower than calculated according to the UNSCEAR risk coefficients. However, further studies are needed to confirm these preliminary results and to improve the quantification of the radiation risk from the medical use of radionuclides. (author)

Superposition of Planckian spectra and the distortions of the cosmic microwave background radiation

International Nuclear Information System (INIS)

Alexanian, M.

1982-01-01

A fit of the spectrum of the cosmic microwave background radiation (CMB) by means of a positive linear superposition of Planckian spectra implies an upper bound to the photon spectrum. The observed spectrum of the CMB gives a weighting function with a normalization greater than unity

Estimates of radiation doses from various sources of exposure

International Nuclear Information System (INIS)

Anon.

1992-01-01

This chapter provides an overview of radiation doses to individuals and to the collective US population from various sources of ionizing radiation. Summary tables present doses from various sources of ionizing radiation. Summary tables present doses from occupational exposures and annual per capita doses from natural background, the healing arts, nuclear weapons, nuclear energy and consumer products. Although doses from non-ionizing radiation are not as yet readily available in a concise form, the major sources of non-ionizing radiation are listed

Analysis of T101 outage radiation dose

International Nuclear Information System (INIS)

Li, Zhonghua

2008-01-01

Full text: Collective radiation dose during outage is about 80% of annual collective radiation dose at nuclear power plants (NPPs). T 101 Outage is the first four-year outage of Unit 1 at Tianwan Nuclear Power Station (TNPS) and thorough overhaul was undergone for the 105-day's duration. Therefore, T 101 Outage has significant reference meaning to reducing collective radiation dose at TNPS. This paper collects the radiation dose statistics during T 101 Outage and analyses the radiation dose distribution according to tasks, work kinds and varying trend of the collective radiation dose etc., comparing with other similar PWRs in the world. Based on the analysis this paper attempts to find out the major factors in collective radiation dose during T 101 Outage. The major positive factor is low radiation level at workplace, which profits from low content of Co in reactor construction materials, optimised high-temperature p H value of the primary circuit coolant within the tight range and reactor operation without trips within the first fuel cycle. One of the most negative factors is long outage duration and many person-hours spent in the radiological controlled zone, caused by too many tasks and inefficient work. So besides keeping good performance of reducing radioactive sources, it should be focused on how to improve implementation of work management including work selection, planning and scheduling, work preparation, work implementation, work assessment and feedback, which can lead to reduced numbers of workers needed to perform a task, of person-hours spent in the radiological controlled zone. Moreover, this leads to reduce occupational exposures in an ALARA fashion. (author)

Effects of low dose gamma radiation on the early growth of red pepper and the resistance to subsquent high dose of radiation

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Baek, M. H.; Kim, D. H.; Lee, Y. K. [KAERI, Taejon (Korea, Republic of); Lee, Y. B. [Chungnam National Univ., Taejon (Korea, Republic of)

2001-05-01

Red pepper (capsicum annuum L. cv. Jokwang and cv. Johong) seeds were irradiated with the dose of 0{approx}50 Gy to investigated the effect of the low dose gamma radiation on the early growth and resistance to subsequent high dose of radiation. The effect of the low dose gamma radiation on the early growth and resistance to subsequenct high dose of radiation were enhanced in Johong cultivar but not in Jokwang cultivar. Germination rate and early growth of Johong cultivar were noticeably increased at 4 Gy-, 8 Gy- and 20 Gy irradiation group. Resistance to subsequent high dose of radiation of Johong cultivar were increased at almost all of the low dose irradiation group. Especially it was highest at 4 Gy irradiation group. The carotenoid contents and enzyme activity on the resistance to subsequent high dose of radiation of Johong cultivar were increased at the 4 Gy and 8 Gy irradiation group.

Fiber optics in high dose radiation fields

International Nuclear Information System (INIS)

Partin, J.K.

1985-01-01

A review of the behavior of state-of-the-art optical fiber waveguides in high dose (greater than or equal to 10 5 rad), steady state radiation fields is presented. The influence on radiation-induced transmission loss due to experimental parameters such as dose rate, total dose, irradiation history, temperature, wavelength, and light intensity, for future work in high dose environments are given

Radiation dose assessment in nuclear medicine

International Nuclear Information System (INIS)

Stabin, M.G.

2002-01-01

In any application involving the use of ionizing radiation in humans, risks and benefits must be properly evaluated and balanced. Radionuclides are used in nuclear medicine in a variety of diagnostic and therapeutic procedures. Recently, interest has grown in therapeutic agents for a number of applications in nuclear medicine, particularly in the treatment of hematologic and non-hematologic malignancies. This has heightened interest in the need for radiation dose calculations and challenged the scientific community to develop more patient-specific and relevant dose models. Consideration of radiation dose in such studies is central to efforts to maximize dose to tumor while sparing normal tissues. In many applications, a significant absorbed dose may be received by some radiosensitive organs, particularly the active marrow. This talk will review the methods and models used in internal dosimetry in nuclear medicine, and discuss some current trends and challenges in this field

Calculation of the dose caused by internal radiation

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

For the purposes of monitoring radiation exposure it is necessary to determine or to estimate the dose caused by both external and internal radiation. When comparing the value of exposure to the dose limits, account must be taken of the total dose incurred from different sources. This guide explains how to calculate the committed effective dose caused by internal radiation and gives the conversion factors required for the calculation. Application of the maximum values for radiation exposure is dealt with in ST guide 7.2, which also sets out the definitions of the quantities and concepts most commonly used in the monitoring of radiation exposure. The monitoring of exposure and recording of doses are dealt with in ST Guides 7.1 and 7.4.

Measuring radiation dose to patients undergoing fluoroscopically-guided interventions

International Nuclear Information System (INIS)

Lubis, L E; Badawy, M K

2016-01-01

The increasing prevalence and complexity of fluoroscopically guided interventions (FGI) raises concern regarding radiation dose to patients subjected to the procedure. Despite current evidence showing the risk to patients from the deterministic effects of radiation (e.g. skin burns), radiation induced injuries remain commonplace. This review aims to increase the awareness surrounding radiation dose measurement for patients undergoing FGI. A review of the literature was conducted alongside previous researches from the authors’ department. Studies pertaining to patient dose measurement, its formalism along with current advances and present challenges were reviewed. Current patient monitoring techniques (using available radiation dosimeters), as well as the inadequacy of accepting displayed dose as patient radiation dose is discussed. Furthermore, advances in real-time patient radiation dose estimation during FGI are considered. Patient dosimetry in FGI, particularly in real time, remains an ongoing challenge. The increasing occurrence and sophistication of these procedures calls for further advances in the field of patient radiation dose monitoring. Improved measuring techniques will aid clinicians in better predicting and managing radiation induced injury following FGI, thus improving patient care. (paper)

Airplane radiation dose decrease during a strong Forbush decrease

Czech Academy of Sciences Publication Activity Database

Spurný, František; Kudela, K.; Dachev, T.

2004-01-01

Roč. 2, S05001 (2004), s. 1-4 ISSN 1542-7390 Grant - others:EC project(XE) FIGM-CT2000-00068 Institutional research plan: CEZ:AV0Z1048901 Keywords : airplane dose * Forbush decrease * cosmic rays Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

Mars' Surface Radiation Environment Measured with the Mars Science Laboratory's Curiosity Rover

Science.gov (United States)

Hassler, Donald M.; Zeitlin, Cary; Wimmer-Schweingruber, Robert F.; Ehresmann, Bent; Rafkin, Scot; Eigenbrode, Jennifer L.; Brinza, David E.; Weigle, Gerald; Böttcher, Stephan; Böhm, Eckart; Burmeister, Soenke; Guo, Jingnan; Köhler, Jan; Martin, Cesar; Reitz, Guenther; Cucinotta, Francis A.; Kim, Myung-Hee; Grinspoon, David; Bullock, Mark A.; Posner, Arik; Gómez-Elvira, Javier; Vasavada, Ashwin; Grotzinger, John P.; MSL Science Team; Kemppinen, Osku; Cremers, David; Bell, James F.; Edgar, Lauren; Farmer, Jack; Godber, Austin; Wadhwa, Meenakshi; Wellington, Danika; McEwan, Ian; Newman, Claire; Richardson, Mark; Charpentier, Antoine; Peret, Laurent; King, Penelope; Blank, Jennifer; Schmidt, Mariek; Li, Shuai; Milliken, Ralph; Robertson, Kevin; Sun, Vivian; Baker, Michael; Edwards, Christopher; Ehlmann, Bethany; Farley, Kenneth; Griffes, Jennifer; Miller, Hayden; Newcombe, Megan; Pilorget, Cedric; Rice, Melissa; Siebach, Kirsten; Stack, Katie; Stolper, Edward; Brunet, Claude; Hipkin, Victoria; Léveillé, Richard; Marchand, Geneviève; Sánchez, Pablo Sobrón; Favot, Laurent; Cody, George; Steele, Andrew; Flückiger, Lorenzo; Lees, David; Nefian, Ara; Martin, Mildred; Gailhanou, Marc; Westall, Frances; Israël, Guy; Agard, Christophe; Baroukh, Julien; Donny, Christophe; Gaboriaud, Alain; Guillemot, Philippe; Lafaille, Vivian; Lorigny, Eric; Paillet, Alexis; Pérez, René; Saccoccio, Muriel; Yana, Charles; Armiens-Aparicio, Carlos; Rodríguez, Javier Caride; Blázquez, Isaías Carrasco; Gómez, Felipe Gómez; Hettrich, Sebastian; Malvitte, Alain Lepinette; Jiménez, Mercedes Marín; Martínez-Frías, Jesús; Martín-Soler, Javier; Martín-Torres, F. Javier; Jurado, Antonio Molina; Mora-Sotomayor, Luis; Caro, Guillermo Muñoz; López, Sara Navarro; Peinado-González, Verónica; Pla-García, Jorge; Manfredi, José Antonio Rodriguez; Romeral-Planelló, Julio José; Fuentes, Sara Alejandra Sans; Martinez, Eduardo Sebastian; Redondo, Josefina Torres; Urqui-O'Callaghan, Roser; Mier, María-Paz Zorzano; Chipera, Steve; Lacour, Jean-Luc; Mauchien, Patrick; Sirven, Jean-Baptiste; Manning, Heidi; Fairén, Alberto; Hayes, Alexander; Joseph, Jonathan; Squyres, Steven; Sullivan, Robert; Thomas, Peter; Dupont, Audrey; Lundberg, Angela; Melikechi, Noureddine; Mezzacappa, Alissa; Berger, Thomas; Matthia, Daniel; Prats, Benito; Atlaskin, Evgeny; Genzer, Maria; Harri, Ari-Matti; Haukka, Harri; Kahanpää, Henrik; Kauhanen, Janne; Kemppinen, Osku; Paton, Mark; Polkko, Jouni; Schmidt, Walter; Siili, Tero; Fabre, Cécile; Wray, James; Wilhelm, Mary Beth; Poitrasson, Franck; Patel, Kiran; Gorevan, Stephen; Indyk, Stephen; Paulsen, Gale; Gupta, Sanjeev; Bish, David; Schieber, Juergen; Gondet, Brigitte; Langevin, Yves; Geffroy, Claude; Baratoux, David; Berger, Gilles; Cros, Alain; d'Uston, Claude; Forni, Olivier; Gasnault, Olivier; Lasue, Jérémie; Lee, Qiu-Mei; Maurice, Sylvestre; Meslin, Pierre-Yves; Pallier, Etienne; Parot, Yann; Pinet, Patrick; Schröder, Susanne; Toplis, Mike; Lewin, Éric; Brunner, Will; Heydari, Ezat; Achilles, Cherie; Oehler, Dorothy; Sutter, Brad; Cabane, Michel; Coscia, David; Israël, Guy; Szopa, Cyril; Dromart, Gilles; Robert, François; Sautter, Violaine; Le Mouélic, Stéphane; Mangold, Nicolas; Nachon, Marion; Buch, Arnaud; Stalport, Fabien; Coll, Patrice; François, Pascaline; Raulin, François; Teinturier, Samuel; Cameron, James; Clegg, Sam; Cousin, Agnès; DeLapp, Dorothea; Dingler, Robert; Jackson, Ryan Steele; Johnstone, Stephen; Lanza, Nina; Little, Cynthia; Nelson, Tony; Wiens, Roger C.; Williams, Richard B.; Jones, Andrea; Kirkland, Laurel; Treiman, Allan; Baker, Burt; Cantor, Bruce; Caplinger, Michael; Davis, Scott; Duston, Brian; Edgett, Kenneth; Fay, Donald; Hardgrove, Craig; Harker, David; Herrera, Paul; Jensen, Elsa; Kennedy, Megan R.; Krezoski, Gillian; Krysak, Daniel; Lipkaman, Leslie; Malin, Michael; McCartney, Elaina; McNair, Sean; Nixon, Brian; Posiolova, Liliya; Ravine, Michael; Salamon, Andrew; Saper, Lee; Stoiber, Kevin; Supulver, Kimberley; Van Beek, Jason; Van Beek, Tessa; Zimdar, Robert; French, Katherine Louise; Iagnemma, Karl; Miller, Kristen; Summons, Roger; Goesmann, Fred; Goetz, Walter; Hviid, Stubbe; Johnson, Micah; Lefavor, Matthew; Lyness, Eric; Breves, Elly; Dyar, M. Darby; Fassett, Caleb; Blake, David F.; Bristow, Thomas; DesMarais, David; Edwards, Laurence; Haberle, Robert; Hoehler, Tori; Hollingsworth, Jeff; Kahre, Melinda; Keely, Leslie; McKay, Christopher; Wilhelm, Mary Beth; Bleacher, Lora; Brinckerhoff, William; Choi, David; Conrad, Pamela; Dworkin, Jason P.; Floyd, Melissa; Freissinet, Caroline; Garvin, James; Glavin, Daniel; Harpold, Daniel; Jones, Andrea; Mahaffy, Paul; Martin, David K.; McAdam, Amy; Pavlov, Alexander; Raaen, Eric; Smith, Michael D.; Stern, Jennifer; Tan, Florence; Trainer, Melissa; Meyer, Michael; Voytek, Mary; Anderson, Robert C.; Aubrey, Andrew; Beegle, Luther W.; Behar, Alberto; Blaney, Diana; Calef, Fred; Christensen, Lance; Crisp, Joy A.; DeFlores, Lauren; Ehlmann, Bethany; Feldman, Jason; Feldman, Sabrina; Flesch, Gregory; Hurowitz, Joel; Jun, Insoo; Keymeulen, Didier; Maki, Justin; Mischna, Michael; Morookian, John Michael; Parker, Timothy; Pavri, Betina; Schoppers, Marcel; Sengstacken, Aaron; Simmonds, John J.; Spanovich, Nicole; Juarez, Manuel de la Torre; Webster, Christopher R.; Yen, Albert; Archer, Paul Douglas; Jones, John H.; Ming, Douglas; Morris, Richard V.; Niles, Paul; Rampe, Elizabeth; Nolan, Thomas; Fisk, Martin; Radziemski, Leon; Barraclough, Bruce; Bender, Steve; Berman, Daniel; Dobrea, Eldar Noe; Tokar, Robert; Vaniman, David; Williams, Rebecca M. E.; Yingst, Aileen; Lewis, Kevin; Leshin, Laurie; Cleghorn, Timothy; Huntress, Wesley; Manhès, Gérard; Hudgins, Judy; Olson, Timothy; Stewart, Noel; Sarrazin, Philippe; Grant, John; Vicenzi, Edward; Wilson, Sharon A.; Hamilton, Victoria; Peterson, Joseph; Fedosov, Fedor; Golovin, Dmitry; Karpushkina, Natalya; Kozyrev, Alexander; Litvak, Maxim; Malakhov, Alexey; Mitrofanov, Igor; Mokrousov, Maxim; Nikiforov, Sergey; Prokhorov, Vasily; Sanin, Anton; Tretyakov, Vladislav; Varenikov, Alexey; Vostrukhin, Andrey; Kuzmin, Ruslan; Clark, Benton; Wolff, Michael; McLennan, Scott; Botta, Oliver; Drake, Darrell; Bean, Keri; Lemmon, Mark; Schwenzer, Susanne P.; Anderson, Ryan B.; Herkenhoff, Kenneth; Lee, Ella Mae; Sucharski, Robert; Hernández, Miguel Ángel de Pablo; Ávalos, Juan José Blanco; Ramos, Miguel; Malespin, Charles; Plante, Ianik; Muller, Jan-Peter; Navarro-González, Rafael; Ewing, Ryan; Boynton, William; Downs, Robert; Fitzgibbon, Mike; Harshman, Karl; Morrison, Shaunna; Dietrich, William; Kortmann, Onno; Palucis, Marisa; Sumner, Dawn Y.; Williams, Amy; Lugmair, Günter; Wilson, Michael A.; Rubin, David; Jakosky, Bruce; Balic-Zunic, Tonci; Frydenvang, Jens; Jensen, Jaqueline Kløvgaard; Kinch, Kjartan; Koefoed, Asmus; Madsen, Morten Bo; Stipp, Susan Louise Svane; Boyd, Nick; Campbell, John L.; Gellert, Ralf; Perrett, Glynis; Pradler, Irina; VanBommel, Scott; Jacob, Samantha; Owen, Tobias; Rowland, Scott; Atlaskin, Evgeny; Savijärvi, Hannu; García, César Martín; Mueller-Mellin, Reinhold; Bridges, John C.; McConnochie, Timothy; Benna, Mehdi; Franz, Heather; Bower, Hannah; Brunner, Anna; Blau, Hannah; Boucher, Thomas; Carmosino, Marco; Atreya, Sushil; Elliott, Harvey; Halleaux, Douglas; Rennó, Nilton; Wong, Michael; Pepin, Robert; Elliott, Beverley; Spray, John; Thompson, Lucy; Gordon, Suzanne; Newsom, Horton; Ollila, Ann; Williams, Joshua; Vasconcelos, Paulo; Bentz, Jennifer; Nealson, Kenneth; Popa, Radu; Kah, Linda C.; Moersch, Jeffrey; Tate, Christopher; Day, Mackenzie; Kocurek, Gary; Hallet, Bernard; Sletten, Ronald; Francis, Raymond; McCullough, Emily; Cloutis, Ed; ten Kate, Inge Loes; Kuzmin, Ruslan; Arvidson, Raymond; Fraeman, Abigail; Scholes, Daniel; Slavney, Susan; Stein, Thomas; Ward, Jennifer; Berger, Jeffrey; Moores, John E.

2014-01-01

The Radiation Assessment Detector (RAD) on the Mars Science Laboratory's Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for ~300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.

Mars' surface radiation environment measured with the Mars Science Laboratory's Curiosity rover.

Science.gov (United States)

Hassler, Donald M; Zeitlin, Cary; Wimmer-Schweingruber, Robert F; Ehresmann, Bent; Rafkin, Scot; Eigenbrode, Jennifer L; Brinza, David E; Weigle, Gerald; Böttcher, Stephan; Böhm, Eckart; Burmeister, Soenke; Guo, Jingnan; Köhler, Jan; Martin, Cesar; Reitz, Guenther; Cucinotta, Francis A; Kim, Myung-Hee; Grinspoon, David; Bullock, Mark A; Posner, Arik; Gómez-Elvira, Javier; Vasavada, Ashwin; Grotzinger, John P

2014-01-24

The Radiation Assessment Detector (RAD) on the Mars Science Laboratory's Curiosity rover began making detailed measurements of the cosmic ray and energetic particle radiation environment on the surface of Mars on 7 August 2012. We report and discuss measurements of the absorbed dose and dose equivalent from galactic cosmic rays and solar energetic particles on the martian surface for ~300 days of observations during the current solar maximum. These measurements provide insight into the radiation hazards associated with a human mission to the surface of Mars and provide an anchor point with which to model the subsurface radiation environment, with implications for microbial survival times of any possible extant or past life, as well as for the preservation of potential organic biosignatures of the ancient martian environment.

Calculating radiation exposure and dose

International Nuclear Information System (INIS)

Hondros, J.

1987-01-01

This paper discusses the methods and procedures used to calculate the radiation exposures and radiation doses to designated employees of the Olympic Dam Project. Each of the three major exposure pathways are examined. These are: gamma irradiation, radon daughter inhalation and radioactive dust inhalation. A further section presents ICRP methodology for combining individual pathway exposures to give a total dose figure. Computer programs used for calculations and data storage are also presented briefly

Radiation dose to the global flying population

International Nuclear Information System (INIS)

Alvarez, Luis E; Eastham, Sebastian D; Barrett, Steven R H

2016-01-01

Civil airliner passengers and crew are exposed to elevated levels of radiation relative to being at sea level. Previous studies have assessed the radiation dose received in particular cases or for cohort studies. Here we present the first estimate of the total radiation dose received by the worldwide civilian flying population. We simulated flights globally from 2000 to 2013 using schedule data, applying a radiation propagation code to estimate the dose associated with each flight. Passengers flying in Europe and North America exceed the International Commission on Radiological Protection annual dose limits at an annual average of 510 or 420 flight hours per year, respectively. However, this falls to 160 or 120 h on specific routes under maximum exposure conditions. (paper)

Radiation Dose to Post-Chernobyl Cleanup Workers

Science.gov (United States)

Radiation dose calculation for post-Chernobyl Cleanup Workers in Ukraine - both external radiation exposure due to fallout and internal doses due to inhalation (I131 intake) or ingestion of contaminated foodstuffs.

Cosmic radiation and airline pilots. Exposure patterns of Norwegian SAS-pilots 1960 to 1994. Revised Version

International Nuclear Information System (INIS)

Tveten, U.

1999-02-01

The present report is a revised version of an earlier report (IFE/KR/E-96/008). The revision has been carried out since a completely new version of the computational tool has recently been released. All calculations have been redone. The work which is presented in this report is part of a Norwegian epidemiological project, carried out in cooperation between Institute for Energy Technology (IFE), the Norwegian Cancer Registry (NCR) and the Norwegian Radiation Protection Authority (NRPA). Originating from the Norwegian project, a number of similar projects have been started in a number of European countries. The present report lays the ground for estimation of individual exposure histories to cosmic radiation of pilots employed by the the Scandinavian Airlines System (SAS). The result presented in this report (radiation dose rates for the different types of aircraft in the different years) were calculated with the most recent computer program for this purpose, the CARI-5E from the United States Civil Aviation Authority. The other major sources of information used as basis for this work is the collection of old SAS time tables found the the SAS Museum at Fornebu Airport in Oslo, and information provided by members of the Pilots Association in Norway

Cosmic radiation and airline pilots. Exposure patterns of Norwegian SAS-pilots 1960 to 1994. Revised Version

Energy Technology Data Exchange (ETDEWEB)

Tveten, U

1999-02-01

The present report is a revised version of an earlier report (IFE/KR/E-96/008). The revision has been carried out since a completely new version of the computational tool has recently been released. All calculations have been redone. The work which is presented in this report is part of a Norwegian epidemiological project, carried out in cooperation between Institute for Energy Technology (IFE), the Norwegian Cancer Registry (NCR) and the Norwegian Radiation Protection Authority (NRPA). Originating from the Norwegian project, a number of similar projects have been started in a number of European countries. The present report lays the ground for estimation of individual exposure histories to cosmic radiation of pilots employed by the the Scandinavian Airlines System (SAS). The result presented in this report (radiation dose rates for the different types of aircraft in the different years) were calculated with the most recent computer program for this purpose, the CARI-5E from the United States Civil Aviation Authority. The other major sources of information used as basis for this work is the collection of old SAS time tables found the the SAS Museum at Fornebu Airport in Oslo, and information provided by members of the Pilots Association in Norway.

Public effective doses from environmental natural gamma exposures indoors and outdoors in Iran

International Nuclear Information System (INIS)

Sohrabi, Mehdi; Roositalab, Jalil; Mohammadi, Jahangir

2015-01-01

The effective doses of public in Iran due to external gamma exposures from terrestrial radionuclides and from cosmic radiation indoors and outdoors of normal natural background radiation areas were determined by measurements and by calculations. For direct measurements, three measurement methods were used including a NaI(TI) scintillation survey meter for preliminary screening, a pressurised ionising chamber for more precise measurements and early warning measurement equipment systems. Measurements were carried out in a large number of locations indoors and outdoors ∼1000 houses selected randomly in 36 large cities of Iran. The external gamma doses of public from living indoors and outdoors were also calculated based on the radioactivity measurements of samples taken from soil and building materials by gamma spectrometry using a high-resolution HPGe system. The national mean background gamma dose rates in air indoors and outdoors based on measurements are 126.9±24.3 and 111.7±17.72 nGy h -1 , respectively. When the contribution from cosmic rays was excluded, the values indoors and outdoors are 109.2±20.2 and 70.2±20.59.4 nGy h -1 , respectively. The dose rates determined for indoors and outdoors by calculations are 101.5±9.2 and 72.2±9.4 nGy h -1 , respectively, which are in good agreement with directly measured dose rates within statistical variations. By considering a population-weighted mean for terrestrial radiation, the ratio of indoor to outdoor dose rates is 1.55. The mean annual effective dose of each individual member of the public from terrestrial radionuclides and cosmic radiation, indoors and outdoors, is 0.86±0.16 mSv y -1 by measurements and 0.8±0.2 mSv y -1 by calculations. The results of this national survey of public annual effective doses from national natural background external gamma radiation determined by measurements and calculations indoors and outdoors of 1000 houses in 36 cities of Iran are presented and discussed. (authors)

Occupational radiation exposure to low doses of ionizing radiation and female breast cancer

International Nuclear Information System (INIS)

Adelina, P.; Bliznakov, V.; Bairacova, A.

2003-01-01

The aim of this study is to examine the relationship between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed and registered breast cancer [probability of causation - PC] among Bulgarian women who have used different ionizing radiation sources during their working experience. The National Institute of Health (NIH) in US has developed a method for estimating the probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed cancer. We have used this method. A group of 27 women with diagnosed breast cancer has been studied. 11 of them are former workers in NPP - 'Kozloduy', and 16 are from other sites using different sources of ionizing radiation. Analysis was performed for 14 women, for whom full personal data were available. The individual radiation dose for each of them is below 1/10 of the annual dose limit, and the highest cumulative dose for a period of 14 years of occupational exposure is 50,21 mSv. The probability of causation (PC) values in all analyzed cases are below 1%, which confirms the extremely low probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and occurring cases of breast cancer. (orig.)

Estimation of radiation risks at low dose

International Nuclear Information System (INIS)

1990-04-01

The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

Information from the National Institute of Radiation Protection about radiation doses and radiation risks at x-ray screening

International Nuclear Information System (INIS)

1975-05-01

This report gives a specification of data concerning radiation doses and risks at x-ray investigations of lungs. The dose estimations are principally based on measurements performed in 1974 by the National Institute of Radiation Protection. The radiation doses at x-ray screening are of that magnitude that the risk for acute radiation injuries is non-existent. At these low doses it has not either been able to prove that the radiation gives long-range effects as changes in the genes or cancer of late appearance. At considerable higher doses, more than tens of thousands of millirads, a risk of cancer appearance at a small part of all irradiated persons has been proved, based on the assumption that the cancer risk is proportional to the radiation dose. Cancer can thus occure at low radiation doses too. Because of the mass radiography in Sweden 1974 about twenty cases of cancer may appear in the future. (M.S.)

Occupational radiation doses among diagnostic radiation workers in South Korea, 1996-2006

International Nuclear Information System (INIS)

Lee, W. J.; Cha, E. S.; Ha, M.; Jin, Y. W.; Hwang, S. S.; Kong, K. A.; Lee, S. W.; Lee, H. K.; Lee, K. Y.; Kim, H. J.

2009-01-01

This study details the distribution and trends of doses of occupational radiation among diagnostic radiation workers by using the national dose registry between 1996 and 2006 by the Korea Food and Drug Administration. Dose measurements were collected quarterly by the use of thermoluminescent dosemeter personal monitors. A total of 61 732 workers were monitored, including 18 376 radiologic technologists (30%), 13 762 physicians (22%), 9858 dentists (16%) and 6114 dental hygienists (9.9%). The average annual effective doses of all monitored workers decreased from 1.75 to 0.80 mSv over the study period. Among all diagnostic radiation workers, radiologic technologists received both the highest effective and collective doses. Male radiologic technologists aged 30-49 y composed the majority of workers receiving more than 5 mSv in a quarter. More intensive monitoring of occupational radiation exposure and investigation into its health effects on diagnostic radiation workers are required in South Korea. (authors)

Biological effects of low doses of radiation at low dose rate

International Nuclear Information System (INIS)

1996-05-01

The purpose of this report was to examine available scientific data and models relevant to the hypothesis that induction of genetic changes and cancers by low doses of ionizing radiation at low dose rate is a stochastic process with no threshold or apparent threshold. Assessment of the effects of higher doses of radiation is based on a wealth of data from both humans and other organisms. 234 refs., 26 figs., 14 tabs

Exploring the Large Scale Anisotropy in the Cosmic Microwave Background Radiation at 170 GHz

Science.gov (United States)

Ganga, Kenneth Matthew

1994-01-01

In this thesis, data from the Far Infra-Red Survey (FIRS), a balloon-borne experiment designed to measure the large scale anisotropy in the cosmic microwave background radiation, are analyzed. The FIRS operates in four frequency bands at 170, 280, 480, and 670 GHz, using an approximately Gaussian beam with a 3.8 deg full-width-at-half-maximum. A cross-correlation with the COBE/DMR first-year maps yields significant results, confirming the DMR detection of anisotropy in the cosmic microwave background radiation. Analysis of the FIRS data alone sets bounds on the amplitude of anisotropy under the assumption that the fluctuations are described by a Harrison-Peebles-Zel'dovich spectrum and further analysis sets limits on the index of the primordial density fluctuations for an Einstein-DeSitter universe. Galactic dust emission is discussed and limits are set on the magnitude of possible systematic errors in the measurement.

Dose distribution following selective internal radiation therapy

International Nuclear Information System (INIS)

Fox, R.A.; Klemp, P.F.; Egan, G.; Mina, L.L.; Burton, M.A.; Gray, B.N.

1991-01-01

Selective Internal Radiation Therapy is the intrahepatic arterial injection of microspheres labelled with 90Y. The microspheres lodge in the precapillary circulation of tumor resulting in internal radiation therapy. The activity of the 90Y injected is managed by successive administrations of labelled microspheres and after each injection probing the liver with a calibrated beta probe to assess the dose to the superficial layers of normal tissue. Predicted doses of 75 Gy have been delivered without subsequent evidence of radiation damage to normal cells. This contrasts with the complications resulting from doses in excess of 30 Gy delivered from external beam radiotherapy. Detailed analysis of microsphere distribution in a cubic centimeter of normal liver and the calculation of dose to a 3-dimensional fine grid has shown that the radiation distribution created by the finite size and distribution of the microspheres results in an highly heterogeneous dose pattern. It has been shown that a third of normal liver will receive less than 33.7% of the dose predicted by assuming an homogeneous distribution of 90Y

Trends in doses to some UK radiation workers

International Nuclear Information System (INIS)

Best, R.J.; Kendall, G.M.; Pook, E.A.; Saunders, P.J.

1990-01-01

The NRPB runs a Personal Monitoring Service which issues dosemeters and keeps radiation dose records for over 10 000 workers. This database is a valuable source of information on occupational exposure to radiation though it is likely that in future the Central Index of Dose Information (CIDI) will provide more comprehensive statistics, albeit restricted to radiation workers in the sense of Ionising Radiation Regulations. This note describes doses incurred to the end of 1987 with some preliminary figures for 1988. It does not cover the same ground as earlier reports but gives more details of the structure of the monitored population by age and sex and examines evidence that mean radiation doses are decreasing with time. (author)

Radiation Practices. Annual Report 2005

International Nuclear Information System (INIS)

Rantanen, E.

2006-06-01

1764 safety licences for the use of radiation were current at the end of 2005. 1907 responsible parties were engaged in notifiable licence-exempt dental X-ray practices. Regulatory control of the use of radiation was performed through regular inspections performed at places of use, test packages sent by post to dental X-ray facilities and maintenance of the Dose Register. Radiation safety guides were also published and research was conducted in support of regulatory control. STUK conducted 458 inspections of licensed practices and 62 inspections of notifiable licence-exempt dental X-ray practices in 2005. 273 remedial orders and recommendations were issued. Use of one appliance was prohibited. A total of 11 698 workers engaged in radiation work were subject to individual monitoring in 2005. 137 000 dose entries were made in the Dose Register. In no case did the individual dose of any worker exceed the dose limits stipulated in the Radiation Decree. Regulatory control of natural radiation focused on radon at workplaces and exposure of aircrews to cosmic radiation. 90 workplaces including a total of 233 work areas were subject to radon monitoring during 2005. 2600 pilots and cabin crew members were monitored for exposure to cosmic radiation. Metrological activities continued with calibration and development work as in previous years. Regulatory control of the use of non-ionizing radiation in 2005 continued to focus particularly on mobile phones and sunbeds. 15 mobile phone types were tested in market surveillance of mobile phones. A total of 44 sunbed appliances were inspected at 36 sunbed facilities. Most research and development work took place within jointly financed research projects. This work focused especially on developing testing and measuring methods for determining exposure to electromagnetic fields caused by mobile phones and their base stations. There were 13 abnormal incidents involving the use of radiation in 2005. Eight of these incidents concerned

On the anisotropies of cosmic microwave background radiation

International Nuclear Information System (INIS)

Molnar, Z.

1996-01-01

The work gives a brief overview of the topic of cosmic microwave background radiation anisotropies. Then is deals with the so-called Rees-Sciama affect; i.e. with the anisotropies arising between the last scattering surface and us due to transparent huge irregularities. Using the formulas of Special Theory of Relativity it is proven that in the neighbourhood of expanding spherical body the Meszaros calculation (Meszaros 1994) are correct; the inaccuracy is maximally of order 10 -12 . Then the profile of the blue shift of expansion caused by an expanding sphere is calculated for the case, when the radius of this sphere is much smaller that the relevant Hubble radius. Hence the profiles of the shifts of light periods through a void and through a supercluster are given in the most general cases. These cases contain all the three Friedmannian models and both the synchronous and asynchronous clusters. Then the obtained profiles are explicitly decomposed into the sum of the multipole terms, and it is shown that the observed difference between the measured direction of the maximum of dipole anisotropy of cosmic microwave background radiation and the result of Lauer and Postman (1994) is not explainable by the Rees-Sciama effect. This means that no alternative exists to the two possibilities for the explanation of the data of Lauer and Postman; either the either the huge system of Abell clusters is streaming, or the Friedmannian model is queried. The third possibility is, of course, that the data of observations of Lauer and Postman are incorrect. However, any of these three possibilities seem to be strange enough; hence, the problems coming from data of Lauer and Postman further holds. This is the key result of paper. As a further technical result it is also shown that in principle there is no upper limit of Rees-Sciama effect. (author)

Assessment of radiation dose awareness among pediatricians

International Nuclear Information System (INIS)

Thomas, Karen E.; Parnell-Parmley, June E.; Charkot, Ellen; BenDavid, Guila; Krajewski, Connie; Haidar, Salwa; Moineddin, Rahim

2006-01-01

There is increasing awareness among pediatric radiologists of the potential risks associated with ionizing radiation in medical imaging. However, it is not known whether there has been a corresponding increase in awareness among pediatricians. To establish the level of awareness among pediatricians of the recent publicity on radiation risks in children, knowledge of the relative doses of radiological investigations, current practice regarding parent/patient discussions, and the sources of educational input. Multiple-choice survey. Of 220 respondents, 105 (48%) were aware of the 2001 American Journal of Roentgenology articles on pediatric CT and radiation, though only 6% were correct in their estimate of the quoted lifetime excess cancer risk associated with radiation doses equivalent to pediatric CT. A sustained or transient increase in parent questioning regarding radiation doses had been noticed by 31%. When estimating the effective doses of various pediatric radiological investigations in chest radiograph (CXR) equivalents, 87% of all responses (and 94% of CT estimates) were underestimates. Only 15% of respondents were familiar with the ALARA principle. Only 14% of pediatricians recalled any relevant formal teaching during their specialty training. The survey response rate was 40%. Awareness of radiation protection issues among pediatricians is generally low, with widespread underestimation of relative doses and risks. (orig.)

Interstellar cyanogen and the temperature of the cosmic microwave background radiation

Science.gov (United States)

Roth, Katherine C.; Meyer, David M.; Hawkins, Isabel

1993-01-01

We present the results of a recently completed effort to determine the amount of CN rotational excitation in five diffuse interstellar clouds for the purpose of accurately measuring the temperature of the cosmic microwave background radiation (CMBR). In addition, we report a new detection of emission from the strongest hyperfine component of the 2.64 mm CN rotational transition (N = 1-0) in the direction toward HD 21483. We have used this result in combination with existing emission measurements toward our other stars to correct for local excitation effects within diffuse clouds which raise the measured CN rotational temperature above that of the CMBR. After making this correction, we find a weighted mean value of T(CMBR) = 2.729 (+0.023, -0.031) K. This temperature is in excellent agreement with the new COBE measurement of 2.726 +/- 0.010 K (Mather et al., 1993). Our result, which samples the CMBR far from the near-Earth environment, attests to the accuracy of the COBE measurement and reaffirms the cosmic nature of this background radiation. From the observed agreement between our CMBR temperature and the COBE result, we conclude that corrections for local CN excitation based on millimeter emission measurements provide an accurate adjustment to the measured rotational excitation.

STUDIES OF COSMIC-RAY MUONS AND NEUTRONS IN A FIVE-STORY CONCRETE BUILDING.

Science.gov (United States)

Chen, Wei-Lin; Sheu, Rong-Jiun

2018-05-01

This study thoroughly determined the flux and dose rate distributions of cosmic-ray muons and neutrons in a five-story concrete building by comparing measurements with Monte Carlo simulations of cosmic-ray showers. An angular-energy-dependent surface source comprising secondary muons and neutrons at a height of 200 m above ground level was established and verified, which was used to concatenate the shower development in the upper atmosphere with subsequent simulations of radiation transport down to ground level, including the effect of the terrain and studied building. A Berkeley Lab cosmic-ray detector and a highly sensitive Bonner cylinder were used to perform muon and neutron measurements on each building floor. After careful calibration and correction, the measured responses of the two detectors were discovered to be reasonably consistent with the theoretical predictions, thus confirming the validity of the two-step calculation model employed in this study. The annual effective doses from cosmic-ray muons and neutrons on the open roof of the building were estimated to be 115.2 and 35.2 μSv, respectively. Muons and neutrons were attenuated floor-by-floor with different attenuation factors of 0.97 and 0.78, and their resultant dose rates on the first floor of the building were 97.8 and 9.9 μSv, respectively.

Impact of radiation technique, radiation fraction dose, and total cisplatin dose on hearing. Retrospective analysis of 29 medulloblastoma patients

International Nuclear Information System (INIS)

Scobioala, Sergiu; Kittel, Christopher; Ebrahimi, Fatemeh; Wolters, Heidi; Eich, Hans Theodor; Parfitt, Ross; Matulat, Peter; Am Zehnhoff-Dinnesen, Antoinette

2017-01-01

To analyze the incidence and degree of sensorineural hearing loss (SNHL) resulting from different radiation techniques, fractionation dose, mean cochlear radiation dose (D mean ), and total cisplatin dose. In all, 29 children with medulloblastoma (58 ears) with subclinical pretreatment hearing thresholds participated. Radiotherapy (RT) and cisplatin had been applied sequentially according to the HIT MED Guidance. Audiological outcomes up to the latest follow-up (median 2.6 years) were compared. Bilateral high-frequency SNHL was observed in 26 patients (90%). No significant differences were found in mean hearing threshold between left and right ears at any frequency. A significantly better audiological outcome (p < 0.05) was found after tomotherapy at the 6 kHz bone-conduction threshold (BCT) and left-sided 8 kHz air-conduction threshold (ACT) than after a combined radiotherapy technique (CT). Fraction dose was not found to have any impact on the incidence, degree, and time-to-onset of SNHL. Patients treated with CT had a greater risk of SNHL at high frequencies than tomotherapy patients even though D mean was similar. Increase in severity of SNHL was seen when the total cisplatin dose reached above 210 mg/m 2 , with the highest abnormal level found 8-12 months after RT regardless of radiation technique or fraction dose. The cochlear radiation dose should be kept as low as possible in patients who receive simultaneous cisplatin-based chemotherapy. The risk of clinically relevant HL was shown when D mean exceeds 45 Gy independent of radiation technique or radiation regime. Cisplatin ototoxicity was shown to have a dose-dependent effect on bilateral SNHL, which was more pronounced in higher frequencies. (orig.) [de