Physics of intense, high energy radiation effects.

Energy Technology Data Exchange (ETDEWEB)

Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

2011-02-01

This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic

Radiative energy losses from a high-current air-blast arc

International Nuclear Information System (INIS)

Strachan, D.C.; Lidgate, D.; Jones, G.R.

1977-01-01

The importance of total radiation losses from high-current arcs burning in highly accelerated air flows representative of conditions existing in commercial gas-blast switchgear has been investigated. Such losses have been measured both in the high-pressure region upstream of a shaped orifice, where gas velocities are low, and in the region downstream where velocities become supersonic and pressure conditions approach ambient. The dominance of upstream electrode vapor as the source of plasma radiation losses is demonstrated and the importance of radiated losses within the arc energy balance is examined using measured values of axial electric field. For upstream electrodes of elkonite (sintered copper/tungsten) as used in high-power gas-blast circuit breakers, it is shown that some 30--40% of the electrical energy input upstream of the orifice is lost as radiation, while downstream this figure becomes 10--20%. The effect of reservoir pressure on arc electric fields is examined and the contribution to this effect of radiation losses is quantified

Radiation Build-Up Of High Energy Gamma In Shielding Of High Atomic Number

International Nuclear Information System (INIS)

Yuliati, Helfi; Akhadi, Mukhlis

2000-01-01

Research to observe effect of radiation build-up factor (b) in iron (Fe) and lead (Pb) for high energy gamma shielding from exp.137 Cs (E gamma : 662 keV) and exp.60 Co (E gamma : 1332 keV) sources has been carried out. Research was conducted bt counting of radiation intensity behind shielding with its thickness vary from 1 to 5 times of half value thickness (HVT). NaI (TI) detector which connected to multi channel analyzer (MCA) was used for the counting. Calculation result show that all of b value are near to 1 (b∼1) both for Fe and Pb. Without inserting b in calculation, from the experiment it was obtained HVT value of Fe for high gamma radiation of 662 and 1332 keV were : (12,94 n 0,03) mm and (17,33 n 0,01) mm with their deviation standards were 0,2% and 0,06% respectively. Value of HVT for Pb with the same energy were : (6,31 n 0,03) mm and (11,86 n 0,03) mm with their deviation standars were : 0,48% and 0,25% respectively. HVL concept could be applied directly to estimate shielding thickness of high atomic number of high energy gamma radiation, without inserting correction of radiation build-up factor

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

Energy dependence of ulrathin LiF-dosemeters for high energy electrons and high energy X-radiation

International Nuclear Information System (INIS)

Kupfer, T.

1977-02-01

The energy dependence of ultrathin LiF-dosemeters for high energy electrons (5-40 MeV) and high energy X-radiation (6 MV, 42 MV) is experimentally determined. The experimental values are compared to values calculted earlier by other authors. The influence of the thickness of the dosemeters have been considered by comparison of experimental values for 0.03 mm thick dosemeters and theoretical values for 0.13 mm and 0.38 mm thick ones. Also different commersially available dosemeters have been compared by experiments. It is difficult to draw any other conclutions about the energy dependence than that the variation of the relative responce is within +- 3 percent (2S). However the results seems to be sulficient for clinical applications

Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

CERN Document Server

García Alía, Rubén; Wrobel, Frédéric; Brugger, Markus

Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadron...

LET spectrometry with track etch detectors-Use in high-energy radiation fields

International Nuclear Information System (INIS)

Jadrnickova, I.; Spurny, F.

2008-01-01

For assessing the risk from ionizing radiation it is necessary to know not only the absorbed dose but also the quality of the radiation; radiation quality is connected with the physical quantity linear energy transfer (LET). One of the methods of determination of LET is based on chemically etched track detectors. This contribution concerns with a spectrometer of LET based on the track detectors and discusses some results obtained at: ·high-energy radiation reference field created at the SPS accelerator at CERN; and ·onboard of International Space Station where track-etch based LET spectrometer has been exposed 273 days during 'Matrjoshka - R' experiment. Results obtained are compared with the results of studies at some lower-energy neutron sources; some conclusions on the registrability of neutrons and the ability of this spectrometer to determine dose equivalent in high-energy radiation fields are formulated

Radiation-hard silicon photonics for high energy physics and beyond

CERN Multimedia

CERN. Geneva

2016-01-01

Silicon photonics (SiPh) is currently being investigated as a promising technology for future radiation hard optical links. The possibility of integrating SiPh devices with electronics and/or silicon particle sensors as well as an expected very high resistance against radiation damage make this technology particularly interesting for potential use close to the interaction points in future in high energy physics experiments and other radiation-sensitive applications. The presentation will summarize the outcomes of the research on radiation hard SiPh conducted within the ICE-DIP projected.

Development of nuclear energy and radiation textbooks for high school students

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Koo; Park, Pil Han; Choi, Yoon Seok; Kim, Wook; Jeong, Im Soon; Han, Eun Ok [Dept. of Education and Research, Korea Academy of Nuclear Safety, Seoul (Korea, Republic of)

2015-04-15

This study aimed to develop textbooks about nuclear energy and radiation targeting high school students-the leaders of the next generation. Students learn about nuclear power generation and radiation through minimal information in science textbooks; most students acquire concepts through teaching-learning activities between teachers and students. Therefore, if a science teacher has an inaccurate perception about nuclear energy and radiation, this may have an improper influence on students. Before the failure of securing social acceptance due to ignorance about nuclear energy and radiation leads to biased political effects, the correct information should be provided in schools to allow future generations to develop educated value judgments. The present textbooks were developed as a part of such effort.

Development of nuclear energy and radiation textbooks for high school students

International Nuclear Information System (INIS)

Lee, Seung Koo; Park, Pil Han; Choi, Yoon Seok; Kim, Wook; Jeong, Im Soon; Han, Eun Ok

2015-01-01

This study aimed to develop textbooks about nuclear energy and radiation targeting high school students-the leaders of the next generation. Students learn about nuclear power generation and radiation through minimal information in science textbooks; most students acquire concepts through teaching-learning activities between teachers and students. Therefore, if a science teacher has an inaccurate perception about nuclear energy and radiation, this may have an improper influence on students. Before the failure of securing social acceptance due to ignorance about nuclear energy and radiation leads to biased political effects, the correct information should be provided in schools to allow future generations to develop educated value judgments. The present textbooks were developed as a part of such effort

Radiation of transient high-current arcs: energy measurements in the optical range

International Nuclear Information System (INIS)

Bauchire, J M; Hong, D; Rabat, H; Riquel, G

2012-01-01

When no protection is used, the radiation emitted by a high-power electric arc can be dangerous for the eyes and the skin of a person. To ensure effective protection, it is first necessary to know the energy emitted by such arcs. The aim of our work was to experimentally determine the energy emitted by high-current (from 4 to 40 kA) transient arcs, for two different (10 cm and 2 m) lengths and for electrodes in copper or steel. These experiments enabled the radiative energy of the arcs to be quantified and also showed the influence of metal vapors in the spectral distribution of the radiation.

System for determining absorbed dose and its distribution for high-energy electron radiation

International Nuclear Information System (INIS)

Hegewald, H.; Wulff, W.

1977-01-01

Taking into account the polarization effect, the dose determination for high-energy electron radiation from particle accelerators depends on the knowledge of the energy dependence of the mass stopping power. Results obtained with thermoluminescent dosemeters agree with theoretical values. For absorbed dose measurements the primary energy of electron radiation has been determined by nuclear photoreactions, and the calculation of the absorbed dose from charge measurements by means of the mass stopping power is described. Thus the calibration of ionization chambers for high-energy electron radiation by absolute measurements with the Faraday cage and chemical dosemeters has become possible. (author)

The response of film badge dosemeters to high energy photon radiation

International Nuclear Information System (INIS)

Playle, T.S.

1988-12-01

The sites of the earlier magnox reactor power stations at Berkeley and Bradwell in the United Kingdom are subject to 6 MeV photon radiation from the coolant gas. Since 1966 the Central Electricity Generating Board has included in its film badge personal dosimetry procedures an algorithm for applying a correction for over-response to high energy photon radiation. The correction is based on laboratory irradiations using a source of pure 6 MeV photon radiation. Recently, the opportunity arose to evaluate the response of the film badges at locations around the Berkeley reactors where spectrum-dependent dose equivalent rates had been measured. This report compares the response of the film badge in these characterised radiation environments with the response measured in the calibration laboratory. It is concluded that in the location where measurements were made, the high energy enhancement of measured dose was obscured by the effects of low energy scattered radiation, and it is considered that this will be the case for all practical situations on the power station site. There is therefore no advantage in using the 6 MeV correction factors for routine film badge dosimetry in these locations. (author)

Comparison between the mechanical and radiative electron-capture processes at high energies

International Nuclear Information System (INIS)

Gonzalez, A.D.; Miraglia, J.E.

1984-01-01

The ground-state--ground-state mechanical and radiative electron-capture processes are studied at very high, but not relativistic, projectile velocities. Three-body calculations were carried out with use of the continuum distorted-wave theoretical method for both processes. Total cross sections and final-atom angular distributions were computed, and the importance of each mechanism examined. For total cross sections, the numerical results reaffirm that the radiative process is the predominant mechanism at very high projectile energies. For a given incident charge, the range of projectile energies in which the nonrelativistic radiative mechanism is the most important decreases as the target charge increases. It is found that the radiative mechanism produces a very sharp final-atom angular distribution in the forward direction. When both processes, the radiative and mechanical, give the same total cross section, the calculations show that the radiative differential cross section in the forward direction is almost 2 orders of magnitude larger than the mechanical one

High Energy Ion Acceleration by Extreme Laser Radiation Pressure

Science.gov (United States)

2017-03-14

published in the internationally leading journal Physical Review Letters. We continued to progress this pionee 15.  SUBJECT TERMS ion therapy, heavy ion ...Thomson parabola spectrometer: To separate and provide a measurement of the charge -to-mass ratio and energy spectrum of the different ion species...AFRL-AFOSR-UK-TR-2017-0015 High energy ion acceleration by extreme laser radiation pressure Paul McKenna UNIVERSITY OF STRATHCLYDE VIZ ROYAL COLLEGE

An investigation of fission models for high-energy radiation transport calculations

International Nuclear Information System (INIS)

Armstrong, T.W.; Cloth, P.; Filges, D.; Neef, R.D.

1983-07-01

An investigation of high-energy fission models for use in the HETC code has been made. The validation work has been directed checking the accuracy of the high-energy radiation transport computer code HETC to investigate the appropriate model for routine calculations, particularly for spallation neutron source applications. Model calculations are given in terms of neutron production, fission fragment energy release, and residual nuclei production for high-energy protons incident on thin uranium targets. The effect of the fission models on neutron production from thick uranium targets is also shown. (orig.)

A study of build-up effects in high-energy radiation fields using a TEPC

Energy Technology Data Exchange (ETDEWEB)

Hoefert, M; Stevenson, G R [CERN, European Laboratory for Particle Physics, Geneva (Switzerland); Aroua, A [IAR, Institute for Applied Radiophysics, Lausanne (Switzerland); Sannikov, A V [IHEP, Institute for High-Energy Physics, Protvino (Russian Federation)

1995-09-04

A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

A study of build-up effects in high-energy radiation fields using a TEPC

International Nuclear Information System (INIS)

Hoefert, M.; Stevenson, G.R.; Aroua, A.; Sannikov, A.V.

1995-01-01

A dose of 2 mSv close to the body surface of a pregnant woman is considered by ICRP to assure a dose limit of 1 mSv to the foetus. Such an assumption depends on the energy spectrum and composition of the external radiation field and it was tested in radiation fields containing high-energy particles similar to those found around high-energy particle accelerators and in air-craft. Measurements of dose and dose equivalent were performed as a function of wall thickness using a tissue-equivalent proportional counter (TEPC) in radiation fields at the CERN-EU Reference Radiation Facility. Results are presented both with respect to integral quantities and event size spectra. The decrease in dose and dose equivalent at a depth equivalent to that of the foetus was typically 10% in a high-energy stray radiation field and in the case of PuBe source neutrons amounted to only 30%. It is concluded that it would be prudent under such exposure conditions to limit the dose of a pregnant woman to 1 mSv in order to assure that the dose to the foetus remains below the same limit. (author)

Radiation protection of the operation of accelerator facilities. On high energy proton and electron accelerators

International Nuclear Information System (INIS)

Kondo, Kenjiro

1997-01-01

Problems in the radiation protection raised by accelerated particles with energy higher than several hundreds MeV in strong accelerator facilities were discussed in comparison with those with lower energy in middle- and small-scale facilities. The characteristics in the protection in such strong accelerator facilities are derived from the qualitative changes in the interaction between the high energy particles and materials and from quantitative one due to the beam strength. In the former which is dependent on the emitting mechanism of the radiation, neutron with broad energy spectrum and muon are important in the protection, and in the latter, levels of radiation and radioactivity which are proportional to the beam strength are important. The author described details of the interaction between high energy particles and materials: leading to the conclusion that in the electron accelerator facilities, shielding against high energy-blemsstrahlung radiation and -neutron is important and in the proton acceleration, shielding against neutron is important. The characteristics of the radiation field in the strong accelerator facilities: among neutron, ionized particles and electromagnetic wave, neutron is most important in shielding since it has small cross sections relative to other two. Considerations for neutron are necessary in the management of exposure. Multiplicity of radionuclides produced: which is a result of nuclear spallation reaction due to high energy particles, especially to proton. Radioactivation of the accelerator equipment is a serious problem. Other problems: the interlock systems, radiation protection for experimenters and maintenance of the equipment by remote systems. (K.H.). 11 refs

Activities of the Radiation Shielding Information Center and a report on codes/data for high energy radiation transport

International Nuclear Information System (INIS)

Roussin, R.W.

1993-01-01

From the very early days in its history Radiation Shielding Information Center (RSIC) has been involved with high energy radiation transport. The National Aeronautics and Space Administration was an early sponsor of RSIC until the completion of the Apollo Moon Exploration Program. In addition, the intranuclear cascade work of Bertini at Oak Ridge National Laboratory provided valuable resources which were made available through RSIC. Over the years, RSIC has had interactions with many of the developers of high energy radiation transport computing technology and data libraries and has been able to collect and disseminate this technology. The current status of this technology will be reviewed and prospects for new advancements will be examined

Effect of high linear energy transfer radiation on biological membranes

International Nuclear Information System (INIS)

Choudhary, D.; Srivastava, M.; Kale, R.K.; Sarma, A.

1998-01-01

Cellular membranes are vital elements, and their integrity is extremely essential for the viability of the cells. We studied the effects of high linear energy transfer (LET) radiation on the membranes. Rabbit erythrocytes (1 x 10 7 cells/ml) and microsomes (0.6 mg protein/ml) prepared from liver of rats were irradiated with 7 Li ions of energy 6.42 MeV/u and 16 O ions of energy 4.25 MeV/u having maximum LET values of 354 keV/μm and 1130 keV/μm, respectively. 7 Li- and 16 O-induced microsomal lipid peroxidation was found to increase with fluence. The 16 O ions were more effective than 7 Li ions, which could be due to the denser energy distribution in the track and the yield of free radicals. These findings suggested that the biological membranes could be peroxidized on exposure to high-LET radiation. Inhibition of the lipid peroxidation was observed in the presence of a membrane-active drug, chlorpromazine (CPZ), which could be due to scavenging of free radicals (mainly HO. and ROO.), electron donation, and hydrogen transfer reactions. The 7 Li and 16 O ions also induced hemolysis in erythrocytes. The extent of hemolysis was found to be a function of time and fluence, and showed a characteristic sigmoidal pattern. The 16 O ions were more effective in the lower fluence range than 7 Li ions. These results were compared with lipid peroxidation and hemolysis induced by gamma-radiation. (orig.)

Control of the radiation environment and the worker in high-energy facilities

International Nuclear Information System (INIS)

Stevenson, G.R.

1993-01-01

The philosophy behind the prediction, measurement, monitoring and limitation by access control of the radiation hazard in high-energy accelerator facilities is compared with that which could be employed for controlling similar hazards due to cosmic radiation in civil aircraft flights. Special mention is made of computer simulations of the radiation environment as a means of predicting necessary control measures, of the reliability and integration of radiation measuring devices into control procedures and of the relevance of different access control procedures. (author)

Radiation effects on integrated circuits used in high energy research

International Nuclear Information System (INIS)

Kanofsky, A.S.; Yost, B.; Farr, W.

1990-01-01

The authors report here on radiation effects on two amplifiers used in high energy experiments. These are standard devices that are produced by LeCroy. They describe each of the devices and the experimental techniques. Finally, they present and discuss the results of the measurements. 5 figs

Use of high energy radiation in decomposition and removal of organic water pollutants

International Nuclear Information System (INIS)

Toelgyessy, P.

1990-01-01

The present review deals with the radiation chemistry of dilute aqueous solutions of organic substances emphasizing the possibility of use of high energy radiation in waste water treatment. Effects of radiation on biodegradability, toxicity to water organisms and changes in molecules of solutes showing resistance to biochemical degradation and toxicity to water organisms are discussed. (author) 31 refs

Radiation environment in the tunnel of a high-energy proton accelerator at energies near 1 TeV

International Nuclear Information System (INIS)

McCaslin, J.B.; Sun, R.K.S.; Swanson, W.P.

1987-12-01

Neutron energy spectra, fluence distributions and rates in the FNAL Tevatron tunnel are summarized. This work has application to radiation damage to electronics and research equipment at high energy accelerators, as well as to radiological protection. 7 refs., 4 figs

Radiative corrections to high-energy neutrino scattering

International Nuclear Information System (INIS)

Rujula, A. de; Petronzio, R.; Savoy-Navarro, A.

1979-01-01

Motivated by precise neutrino experiments, the electromagnetic radiative corrections to the data are reconsidered. The usefulness is investigated and the simplicity demonstrated of the 'leading log' approximation: the calculation to order α ln (Q/μ), α ln (Q/msub(q)). Here Q is an energy scale of the overall process, μ is the lepton mass and msub(q) is a hadronic mass, the effective quark mass in a parton model. The leading log radiative corrections to dsigma/dy distributions and to suitably interpreted dsigma/dx distributions are quark-mass independent. The authors improve upon the conventional leading log approximation and compute explicitly the largest terms that lie beyond the leading log level. In practice this means that the model-independent formulae, though approximate, are likely to be excellent estimates everywhere except at low energy or very large y. It is pointed out that radiative corrections to measurements of deviations from the Callan-Gross relation and to measurements of the 'sea' constituency of nucleons are gigantic. The QCD inspired study of deviations from scaling is of particular interest. The authors compute, beyond the leading log level, the radiative corrections of the QCD predictions. (Auth.)

High energy radiation effects on mechanical properties of butyl rubber compounds

International Nuclear Information System (INIS)

Pozenato, Cristina A.; Scagliusi, Sandra R.; Cardoso, Elisabeth C.L.; Lugao, Ademar B.

2013-01-01

The high energy radiation on butyl rubber compounds causes a number of chemical reactions that occur after initial ionization and excitation events. These reactions lead to changes in molecular mass of the polymer through scission and crosslinking of the molecules, being able to affect the physical and mechanical properties. Butyl rubber has excellent mechanical properties and oxidation resistance as well as low gas and water vapor permeability. Due to all these properties butyl rubber is widely used industrially and particularly in tires manufacturing. In accordance with various authors, the major effect of high energy, such as gamma rays in butyl rubber, is the yielding of free-radicals along with changes in mechanical properties. There were evaluated effects imparted from high energy radiation on mechanical properties of butyl rubber compounds, non-irradiated and irradiated with 25 kGy, 50 kGy, 150 kGy and 200 kGy. It was also observed a sharp reducing in stress rupture and elongation at break for doses higher than 50 kGy, pointing toward changes in polymeric chain along build-up of free radicals and consequent degradation. (author)

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

Energy Technology Data Exchange (ETDEWEB)

Bizen, Teruhiko [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)]. E-mail: bizen@spring8.or.jp; Asano, Yoshihiro [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Marechal, Xavier-Marie [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Seike, Takamitsu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Aoki, Tsuyoshi [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukami, Kenji [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hosoda, Naoyasu [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yonehara, Hiroto [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takagi, Tetsuya [JASRI SPring-8, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hara, Toru [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Tanaka, Takashi [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kitamura, Hideo [RIKEN SPring-8 Center, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2007-05-11

High-energy electron-beam bombardment of Nd{sub 2}Fe{sub 14}B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small.

High-energy electron irradiation of NdFeB permanent magnets: Dependence of radiation damage on the electron energy

International Nuclear Information System (INIS)

Bizen, Teruhiko; Asano, Yoshihiro; Marechal, Xavier-Marie; Seike, Takamitsu; Aoki, Tsuyoshi; Fukami, Kenji; Hosoda, Naoyasu; Yonehara, Hiroto; Takagi, Tetsuya; Hara, Toru; Tanaka, Takashi; Kitamura, Hideo

2007-01-01

High-energy electron-beam bombardment of Nd 2 Fe 14 B-type permanent magnets induces radiation damage characterized by a drop in the magnetic field. Experiments carried out at the SPring-8 booster synchrotron, with 4, 6, and 8 GeV electrons, show that the drop in magnetic field is energy dependent. Electromagnetic shower simulations suggest that most of the radiation damage happens in a small region around the irradiation axis, and that the contribution of neutrons with large scattering angles or with low energies to the magnetic field change is small

Radiation hardness of silicon detectors - a challenge from high-energy physics

CERN Document Server

Lindström, G; Fretwurst, E

1999-01-01

An overview of the radiation-damage-induced problems connected with the application of silicon particle detectors in future high-energy physics experiments is given. Problems arising from the expected hadron fluences are summarized and the use of the nonionizing energy loss for normalization of bulk damage is explained. The present knowledge on the deterioration effects caused by irradiation is described leading to an appropriate modeling. Examples are given for a correlation between the change in the macroscopic performance parameters and effects to be seen on the microscopic level by defect analysis. Finally possible ways are out-lined for improving the radiation tolerance of silicon detectors either by operational conditions, process technology or defect engineering.

A self-powered thin-film radiation detector using intrinsic high-energy current

Energy Technology Data Exchange (ETDEWEB)

Zygmanski, Piotr, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Sajo, Erno, E-mail: pzygmanski@LROC.HARVARD.EDU, E-mail: Erno-Sajo@uml.edu [Department of Physics and Applied Physics, Medical Physics Program, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States)

2016-01-15

Purpose: The authors introduce a radiation detection method that relies on high-energy current (HEC) formed by secondary charged particles in the detector material, which induces conduction current in an external readout circuit. Direct energy conversion of the incident radiation powers the signal formation without the need for external bias voltage or amplification. The detector the authors consider is a thin-film multilayer device, composed of alternating disparate electrically conductive and insulating layers. The optimal design of HEC detectors consists of microscopic or nanoscopic structures. Methods: Theoretical and computational developments are presented to illustrate the salient properties of the HEC detector and to demonstrate its feasibility. In this work, the authors examine single-sandwiched and periodic layers of Cu and Al, and Au and Al, ranging in thickness from 100 nm to 300 μm and separated by similarly sized dielectric gaps, exposed to 120 kVp x-ray beam (half-value thickness of 4.1 mm of Al). The energy deposition characteristics and the high-energy current were determined using radiation transport computations. Results: The authors found that in a dual-layer configuration, the signal is in the measurable range. For a defined total detector thickness in a multilayer structure, the signal sharply increases with decreasing thickness of the high-Z conductive layers. This paper focuses on the computational results while a companion paper reports the experimental findings. Conclusions: Significant advantages of the device are that it does not require external power supply and amplification to create a measurable signal; it can be made in any size and geometry, including very thin (sub-millimeter to submicron) flexible curvilinear forms, and it is inexpensive. Potential applications include medical dosimetry (both in vivo and external), radiation protection, and other settings where one or more of the above qualities are desired.

Characterization of CERN-EU high energy reference radiation fields with recombination chamber

International Nuclear Information System (INIS)

Golnik, N.

1998-01-01

The CERN-EU reference radiation field facility (called CERFF) is available behind a shielding of high-energy particles beam at CERN since 1993. At present the parameters of the radiation from beam target are well investigated, however, there are still some serious doubts concerning contribution of low-LET concurrent radiation. This paper presents an experimental procedure for determination of the contribution from the concurrent radiation by measuring the absorbed dose and recombination index of radiation quality at different beam intensities. Additionally, the values of H * (10) were measured in several measuring locations. Measurements were performed with a REM-2 recombination chamber and compared with those obtained by using a HANDI-TEPC instrument. (author)

High energy synchrotron radiation. A new probe for condensed matter research

International Nuclear Information System (INIS)

Schneider, J.R.; Bouchard, R.; Brueckel, T.; Lippert, M.; Neumann, H.B.; Poulsen, H.F.; Ruett, U.; Schmidt, T.; Zimmermann, M. von

1994-01-01

The absorption of 150 keV synchrotron radiation in matter is weak and, as normally done with neutrons, bulk properties are studied in large samples. However, the k-space resolution obtained with a Triple Crystal Diffractometer (TCD) for high energy synchrotron radiation is about one order of magnitude better than in high resolution neutron diffraction. The technique has been applied to measure the structure factor S(Q) of amorphous solids up to momentum transfers of the order of 32 A -1 , to study the intermediate range Ortho-II ordering in large, high quality YBa 2 Cu 3 O 6.5 single crystals and for investigations of the defect scattering from annealed Czochralski grown silicon crystals. Magnetic superlattice reflections have been measured in MnF 2 demonstrating the potential of the technique for high resolution studies of ground state bulk antiferromagnetism. Recently the question of two length scales in the critical scattering at the 100 K phase transition in SrTiO 3 was studied. At the PETRA storage ring, which serves as an accumulator for the HERA electron-proton-ring at DESY and which can be operated up to electron energies of 12 GeV, an undulator beam line is currently under construction and should be available in summer 1995. It opens up exciting new research opportunities for photon energies from about 20 to 150 keV. (orig.)

Radiation tolerant fiber optic humidity sensors for High Energy Physics applications

CERN Document Server

Berruti, Gaia Maria; Cusano, Andrea

This work is devoted to the development of fiber optic humidity sensors to be applied in high-energy physics applications and in particular in experiments currently running at CERN. The high radiation level resulting from the operation of the accelerator at full luminosity can cause serious performance deterioration of the silicon sensors which are responsible for the particle tracking. To increase their lifetime, the sensors must be kept cold at temperatures below 0 C. At such low temperatures, any condensation risk has to be prevented and a precise thermal and hygrometric control of the air filling and surrounding the tracker detector cold volumes is mandatory. The technologies proposed at CERN for relative humidity monitoring are mainly based on capacitive sensing elements which are not designed with radiation resistance characteristic. In this scenario, fiber optic sensors seem to be perfectly suitable. Indeed, the fiber itself, if properly selected, can tolerate a very high level of radiation, optical fi...

A novel transition radiation detector utilizing superconducting microspheres for measuring the energy of relativistic high-energy charged particles

International Nuclear Information System (INIS)

Yuan, Luke C.L.; Chen, C.P.; Huang, C.Y.; Lee, S.C.; Waysand, G.; Perrier, P.; Limagne, D.; Jeudy, V.; Girard, T.

2000-01-01

A novel transition radiation detector (TRD) utilizing superheated superconducting microspheres of tin of 22-26, 27-32 and 32-38 μm in diameter, respectively, has been constructed which is capable of measuring accurately the energy of relativistic high-energy charged particles. The test has been conducted in a high-energy electron beam facility at the CERN PS in the energy range of 1-10 GeV showing an energy dependence of the TR X-ray photon produced and hence the value γ=E/mc 2 of the charged particle

Complex of programs for calculating radiation fields outside plane protecting shields, bombarded by high-energy nucleons

International Nuclear Information System (INIS)

Gel'fand, E.K.; Man'ko, B.V.; Serov, A.Ya.; Sychev, B.S.

1979-01-01

A complex of programs for modelling various radiation situations at high energy proton accelerators is considered. The programs are divided into there main groups according to their purposes. The first group includes programs for preparing constants describing the processes of different particle interaction with a substanc The second group of programs calculates the complete function of particle distribution arising in shields under irradiation by high energy nucleons. Concrete radiation situations arising at high energy proton accelerators are calculated by means of the programs of the third group. A list of programs as well as their short characteristic are given

Complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

CERN Document Server

Bilski, P; D'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

2006-01-01

This report outlines the research needs and research activities within Europe to develop new and improved methods and techniques for the characterization of complex radiation fields at workplaces around high-energy accelerators and the next generation of thermonuclear fusion facilities under the auspices of the COordinated Network for RAdiation Dosimetry (CONRAD) project funded by the European Commission.

A low power high speed radiation hard serializer for High Energy Physics experiments

CERN Document Server

AUTHOR|(CDS)2080243; Marchioro, Alessandro; Ottavi, Marco

This Ph.D. thesis focuses on the development and the characterization of novel solutions for electronic systems for high-speed data transmission in extremely high radio-active environment (e.g. high energy physics application). The text proposes two alternative full-custom solutions for a fundamental enabling block for a lowpower serial data transmission system, the serializer. This block will find place in a future transceiver conceived for the future upgraded phase of the Large Hadron Collider, or LHC, at CERN. The first solution proposed, called “triple module redundancy”, is based on hardware redundancy, a well-known solution, to obtain protection against the temporary malfunctioning induced by radiation. In the second case a new architecture, called “code protected”, is proposed. This architecture takes advantage of the error correction code present in the data word to obtain radiation robustness on data and some parts of the control logic and to further reduce the power consumption. A test chip ...

An investigation of build-up effects in high energy radiation fields using a Handi TEPC

International Nuclear Information System (INIS)

Aroua, A.; Sannikov, A.V.

1995-01-01

ICRP considers that a dose limit of 2 mSv close to the body surface of a pregnant woman will ensure a dose limit of 1 mSv to the foetus. This assumption depends on the energy spectrum and composition of the radiation fields, especially those containing high energy particles such as are found around particle accelerators or in aircraft. In this work the response of a tissue-equivalent proportional counter in radiation fields of different composition and energy was measured as a function of depth in cylindrical phantoms. The decrease in dose and dose equivalent at a phantom depth equivalent to that of a foetus was 10% in a typical high energy stray radiation field and 30% for neutrons from a Pu-Be source. It is concluded that it would be prudent in these cases to limit the exposure of a pregnant woman to 1 mSv in order to ensure that the dose to the foetus stays below the same limit. (Author)

High energy dosimetry

International Nuclear Information System (INIS)

Ruhm, W.

2010-01-01

Full text: Currently, quantification of doses from high-energy radiation fields is a topical issue. This is so because high-energy neutrons play an important role for radiation exposure of air crew members and personnel outside the shielding of ion therapy facilities. In an effort to study air crew exposure from cosmic radiation in detail, two Bonner Sphere Spectrometers (BSSs) have recently been installed to measure secondary neutrons from cosmic radiation, one at the environmental research station 'Schneefernerhaus' at an altitude of 2650 m on the Zugspitze mountain, Germany, the other at the Koldewey station close to the North Pole on Spitsbergen. Based on the measured neutron fluence distributions and on fluence-to-dose conversion coefficients, mean ambient dose equivalent rate values of 75.0 ± 2.9 nSv/h and 8.7 ± 0.6 nSv/h were obtained for October 2008, respectively. Neutrons with energies above about 20 MeV contribute about 50% to dose, at 2650 m. Ambient dose equivalent rates measured by means of a standard rem counter and an extended rem counter at the Schneefernerhaus confirm this result. In order to study the response of state-of-the-art radiation instrumentation in such a high-energy radiation field, a benchmark exercise that included both measurements in and simulation of the stray neutron radiation field at the high-energy particle accelerator at GSI, Germany, were performed. This CONRAD (COordinated Network for RAdiation Dosimetry) project was funded by the European Commission, and the organizational framework was provided by the European Radiation Dosimetry Group, EURADOS. The Monte Carlo simulations of the radiation field and the experimental determination of the neutron spectra with various Bonner Sphere Spectrometers suggest the neutron fluence distributions to be very similar to those of secondary neutrons from cosmic radiation. The results of this intercomparison exercise in terms of ambient dose equivalent are also discussed

Characteristics of background radiation behind one-dimensional radiation shielding of high-energy particle beams; Kharakteristiki fonovogo izlucheniya za odnomernymi radiatsionnymi zashchitami puchkov vysokoehnergeticheskikh chastits

Energy Technology Data Exchange (ETDEWEB)

Gorbatkov, D V; Kryuchkov, V P

1994-12-31

The calculational investigations of component, spatial and energy distributions of background radiation behind radiation shielding of high-energy hadron beams were carried out. The relations between different ingredients of radiation have been obtained. The numerous data of spatial and energy distribution of protons, neutrons, pions and photons in homogeneous and heterogeneous shielding from concrete and iron, presented in the paper, can be used as a reference data. 23 refs., 50 figs.

Low and high linear energy transfer radiation sensitization of HCC cells by metformin

International Nuclear Information System (INIS)

Kim, Eun Ho; Jung, Won-Gyun; Kim, Mi-Sook; Cho, Chul-Koo; Jeong, Youn Kyoung; Jeong, Jae-Hoon

2014-01-01

The purpose of this study was to investigate the efficacy of metformin as a radiosensitizer for use in combination therapy for human hepatocellular carcinoma (HCC). Three human HCC cell lines (Huh7, HepG2, Hep3B) and a normal human hepatocyte cell line were treated with metformin alone or with radiation followed by metformin. In vitro tests were evaluated by clonogenic survival assay, FACS analysis, western blotting, immunofluorescence and comet assay. Metformin significantly enhanced radiation efficacy under high and low Linear Energy Transfer (LET) radiation conditions in vitro. In combination with radiation, metformin abrogated G2/M arrest and increased the cell population in the sub-G1 phase and the ROS level, ultimately increasing HCC cellular apoptosis. Metformin inhibits the repair of DNA damage caused by radiation. The radiosensitizing effects of metformin are much higher in neutron (high LET)-irradiated cell lines than in γ (low LET)-irradiated cell lines. Metformin only had a moderate effect in normal hepatocytes. Metformin enhances the radiosensitivity of HCC, suggesting it may have clinical utility in combination cancer treatment with high-LET radiation. (author)

Radiation effects on semiconductor devices in high energy heavy ion accelerators

Energy Technology Data Exchange (ETDEWEB)

Belousov, Anton

2014-10-20

Radiation effects on semiconductor devices in GSI Helmholtz Center for Heavy Ion Research are becoming more and more significant with the increase of beam intensity due to upgrades. Moreover a new accelerator is being constructed on the basis of GSI within the project of facility for antiproton and ion research (FAIR). Beam intensities will be increased by factor of 100 and energies by factor of 10. Radiation fields in the vicinity of beam lines will increase more than 2 orders of magnitude and so will the effects on semiconductor devices. It is necessary to carry out a study of radiation effects on semiconductor devices considering specific properties of radiation typical for high energy heavy ion accelerators. Radiation effects on electronics in accelerator environment may be divided into two categories: short-term temporary effects and long-term permanent degradation. Both may become critical for proper operation of some electronic devices. This study is focused on radiation damage to CCD cameras in radiation environment of heavy ion accelerator. Series of experiments with irradiation of devices under test (DUTs) by secondary particles produced during ion beam losses were done for this study. Monte Carlo calculations were performed to simulate the experiment conditions and conditions expected in future accelerator. Corresponding comparisons and conclusions were done. Another device typical for accelerator facilities - industrial Ethernet switch was tested in similar conditions during this study. Series of direct irradiations of CCD and MOS transistors with heavy ion beams were done as well. Typical energies of the primary ion beams were 0.5-1 GeV/u. Ion species: from Na to U. Intensities of the beam up to 10{sup 9} ions/spill with spill length of 200-300 ns. Criteria of reliability and lifetime of DUTs in specific radiation conditions were formulated, basing on experimental results of the study. Predictions of electronic device reliability and lifetime were

Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

International Nuclear Information System (INIS)

R Paul Drake

2004-01-01

OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

Dose measurement techniques for high-energy photon and electron radiation

International Nuclear Information System (INIS)

Hohlfeld, K.; Roos, M.

1992-08-01

By law the Federal Institute of Physics and Technology (PTB) has been assigned the tasks of representing, preserving and passing on dose units. The analogous continuation of these tasks consists in improving, at the user level, dosimetry techniques in radiation therapy for the benefit of patients. The PTB had an essential share in working out the scientific foundations of dosimetry for high-energy radiation, and the corresponding DIN standards were established with the PTB playing a prominent part. The seminar aimed at presenting the measuring techniques fixed in the new DIN standard 6800 part 2 'Dose measurement techniques according to the probe method - ionization dosimetry', to discuss their physical background and practical implications resulting from them. (orig.) [de

Collaboration with a local organization on the subjects of energy/radiation field in high school science education

International Nuclear Information System (INIS)

Suzuki, Takahiro; Mori, Chizuo

2005-01-01

We, high school teachers, collaborated with a local organization, Chubu Atomic Power Conference (partly in co-operation with The Radiation Education Forum), in the education on the subjects of energy and radiation fields. In addition to the subjects concerned with radiations, cloud chamber and personal radiation-monitor, we developed a few new subjects, which are not directly connected themselves with radiations, for the purpose to widen the fields and to bring the high acceptability of the subjects in high school side. (author)

Paradigm Shift in Radiation Biology/Radiation Oncology-Exploitation of the "H₂O₂ Effect" for Radiotherapy Using Low-LET (Linear Energy Transfer) Radiation such as X-rays and High-Energy Electrons.

Science.gov (United States)

Ogawa, Yasuhiro

2016-02-25

Most radiation biologists/radiation oncologists have long accepted the concept that the biologic effects of radiation principally involve damage to deoxyribonucleic acid (DNA), which is the critical target, as described in "Radiobiology for the Radiologist", by E.J. Hall and A.J. Giaccia [1]. Although the concepts of direct and indirect effects of radiation are fully applicable to low-LET (linear energy transfer) radioresistant tumor cells/normal tissues such as osteosarcoma cells and chondrocytes, it is believed that radiation-associated damage to DNA does not play a major role in the mechanism of cell death in low-LET radiosensitive tumors/normal tissues such as malignant lymphoma cells and lymphocytes. Hall and Giaccia describe lymphocytes as very radiosensitive, based largely on apoptosis subsequent to irradiation. As described in this review, apoptosis of lymphocytes and lymphoma cells is actually induced by the "hydrogen peroxide (H₂O₂) effect", which I propose in this review article for the first time. The mechanism of lymphocyte death via the H₂O₂ effect represents an ideal model to develop the enhancement method of radiosensitivity for radiation therapy of malignant neoplasms. In terms of imitating the high radiosensitivity of lymphocytes, osteosarcoma cells (representative of low-LET radioresistant cells) might be the ideal model for indicating the conversion of cells from radioresistant to radiosensitive utilizing the H₂O₂ effect. External beam radiation such as X-rays and high-energy electrons for use in modern radiotherapy are generally produced using a linear accelerator. We theorized that when tumors are irradiated in the presence of H₂O₂, the activities of anti-oxidative enzymes such as peroxidases and catalase are blocked and oxygen molecules are produced at the same time via the H₂O₂ effect, resulting in oxidative damage to low-LET radioresistant tumor cells, thereby rendering them highly sensitive to irradiation. In this

New apparatus with high radiation energy between 320 to 460 nm: physical description and dermatological applications

International Nuclear Information System (INIS)

Mutzhas, M.F.; Holzle, E.; Hofmann, C.; Plewig, G.

1981-01-01

A new apparatus (UVASUN 5000) is presented with high radiation energy between 320 to 460 nm. The radiator is a specially developed source for high uv-A intensity, housing a quartz bulb with a mixture of argon, mercury and metal-halides. The uv-A energy in the range of 320 to 400 nm is about 84% of the total radiation energy. Effects of very high doses of uv-A on human skin were studied. Following single uv-A applications the minimal tanning dose uv-A (MTD) and the immediate pigment darkening (IPD) dose of uv-A were established. Repeated exposure to this uv-A delivering system yields long lasting dark brown skin pigmentation without any clinical or histological signs of sunburn (uv-B) damage, epidermal hyperplasia or thickening of the stratum corneum. Minimal therapeutic results were seen in the phototherapy of vitiligo and inflammatory acne

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

Science.gov (United States)

Higuchi, Yoshinori; Nelson, Gregory A.; Vazquez, Marcelo; Laskowitz, Daniel T.; Slater, James M.; Pearlstein, Robert D.

2002-01-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. METHODS: Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. ROTAROD TEST: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. OPEN FIELD TEST: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. MORRIS WATER MAZE: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. CONCLUSIONS: These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the CNS. ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process.

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

International Nuclear Information System (INIS)

Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D.; Laskowitz, D.T.

2002-01-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. Rotarod test: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. Open field test: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. Morris water maze: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the central nervous system (CNS). ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process. (author)

Apolipoprotein E expression and behavioral toxicity of high charge, high energy (HZE) particle radiation

Energy Technology Data Exchange (ETDEWEB)

Higuchi, Yoshinori; Nelson, G.A.; Slater, J.M.; Pearlstein, R.D. [Loma Linda Univ., CA (United States). Medical Center; Vazquez, M. [Brookhaven National Lab., Upton, NY (United States); Laskowitz, D.T. [Duke Univ., Durham, NC (United States). Medical Center

2002-12-01

Apolipoprotein E (apoE) is a lipid binding protein that plays an important role in tissue repair following brain injury. In the present studies, we have investigated whether apoE affects the behavioral toxicity of high charge, high energy (HZE) particle radiation. Sixteen male apoE knockout (KO) mice and sixteen genetically matched wild-type (WT) C57BL mice were used in this experiment. Half of the KO and half of the WT animals were irradiated with 600 MeV/amu iron particles (2 Gy whole body). The effect of irradiation on motor coordination and stamina (Rotarod test), exploratory behavior (open field test), and spatial working and reference memory (Morris water maze) was assessed. Rotarod test: Performance was adversely affected by radiation exposure in both KO and WT groups at 30 d after irradiation. By 60 d after radiation, the radiation effect was lost in WT, but still apparent in irradiated KO mice. Open field test: Radiation reduced open field exploratory activity 14, 28, 56, 84, and 168 d after irradiation of KO mice, but had no effect on WT mice. Morris water maze: Radiation adversely affected spatial working memory in the KO mice, but had no discernible effect in the WT mice as assessed 180 d after irradiation. In contrast, irradiated WT mice showed marked impairment of spatial reference memory in comparison to non-irradiated mice, while no effect of radiation was observed in KO mice. These studies show that apoE expression influences the behavioral toxicity of HZE particle radiation and suggest that apoE plays a role in the repair/recovery from radiation injury of the central nervous system (CNS). ApoE deficiency may exacerbate the previously reported effects of HZE particle radiation in accelerating the brain aging process. (author)

Compilation of radiation damage test data part III: materials used around high-energy accelerators

CERN Document Server

Beynel, P; Schönbacher, H; CERN. Geneva

1982-01-01

For pt.II see CERN report 79-08 (1979). This handbook gives the results of radiation damage tests on various engineering materials and components intended for installation in radiation areas of the CERN high-energy particle accelerators. It complements two previous volumes covering organic cable-insulating materials and thermoplastic and thermosetting resins.

Shielding technology for high energy radiation production facility

International Nuclear Information System (INIS)

Lee, Byung Chul; Kim, Heon Il

2004-06-01

In order to develop shielding technology for high energy radiation production facility, references and data for high energy neutron shielding are searched and collected, and calculations to obtain the characteristics of neutron shield materials are performed. For the evaluation of characteristics of neutron shield material, it is chosen not only general shield materials such as concrete, polyethylene, etc., but also KAERI developed neutron shields of High Density PolyEthylene (HDPE) mixed with boron compound (B 2 O 3 , H 2 BO 3 , Borax). Neutron attenuation coefficients for these materials are obtained for later use in shielding design. The effect of source shape and source angular distribution on the shielding characteristics for several shield materials is examined. This effect can contribute to create shielding concept in case of no detail source information. It is also evaluated the effect of the arrangement of shield materials using current shield materials. With these results, conceptual shielding design for PET cyclotron is performed. The shielding composite using HDPE and concrete is selected to meet the target dose rate outside the composite, and the dose evaluation is performed by configuring the facility room conceptually. From the result, the proper shield configuration for this PET cyclotron is proposed

Laser-Driven Very High Energy Electron/Photon Beam Radiation Therapy in Conjunction with a Robotic System

Directory of Open Access Journals (Sweden)

Kazuhisa Nakajima

2014-12-01

Full Text Available We present a new external-beam radiation therapy system using very-high-energy (VHE electron/photon beams generated by a centimeter-scale laser plasma accelerator built in a robotic system. Most types of external-beam radiation therapy are delivered using a machine called a medical linear accelerator driven by radio frequency (RF power amplifiers, producing electron beams with an energy range of 6–20 MeV, in conjunction with modern radiation therapy technologies for effective shaping of three-dimensional dose distributions and spatially accurate dose delivery with imaging verification. However, the limited penetration depth and low quality of the transverse penumbra at such electron beams delivered from the present RF linear accelerators prevent the implementation of advanced modalities in current cancer treatments. These drawbacks can be overcome if the electron energy is increased to above 50 MeV. To overcome the disadvantages of the present RF-based medical accelerators, harnessing recent advancement of laser-driven plasma accelerators capable of producing 1-GeV electron beams in a 1-cm gas cell, we propose a new embodiment of the external-beam radiation therapy robotic system delivering very high-energy electron/photon beams with an energy of 50–250 MeV; it is more compact, less expensive, and has a simpler operation and higher performance in comparison with the current radiation therapy system.

High dose radiation damage in nuclear energy structural materials investigated by heavy ion irradiation simulation

International Nuclear Information System (INIS)

Zheng Yongnan; Xu Yongjun; Yuan Daqing

2014-01-01

Structural materials in ITER, ADS and fast reactor suffer high dose irradiations of neutrons and/or protons, that leads to severe displacement damage up to lOO dpa per year. Investigation of radiation damage induced by such a high dose irradiation has attracted great attention along with the development of nuclear energy facilities of new generation. However, it is deeply hampered for the lacking of high dose neutron and proton sources. Irradiation simulation of heavy ions produced by accelerators opens up an effective way for laboratory investigation of high dose irradiation induced radiation damage encountered in the ITER, ADS, etc. Radiation damage is caused mainly by atomic displacement in materials. The displacement rate of heavy ions is about lO 3 ∼10 7 orders higher than those of neutrons and protons. High displacement rate of heavy ions significantly reduces the irradiation time. The heavy ion irradiation simulation technique (HIIS) technique has been developed at China Institute of Atomic Energy and a series of the HIIS experiments have been performed to investigate radiation damage in stainless steels, tungsten and tantalum at irradiation temperatures from room temperature to 800 ℃ and in the irradiation dose region up to 100 dpa. The experimental results show that he radiation swelling peak for the modified stainless steel appears in the temperature region around 580 ℃ and the radiation damage is more sensitive to the temperature, the size of the radiation induced vacancy cluster or void increase with the increasing of the irradiation dose, and among the three materials the home-made modified stainless steel has the best radiation resistant property. (authors)

High linear-energy-transfer radiation can overcome radioresistance of glioma stem-like cells to low linear-energy-transfer radiation.

Science.gov (United States)

Hirota, Yuki; Masunaga, Shin-Ichiro; Kondo, Natsuko; Kawabata, Shinji; Hirakawa, Hirokazu; Yajima, Hirohiko; Fujimori, Akira; Ono, Koji; Kuroiwa, Toshihiko; Miyatake, Shin-Ichi

2014-01-01

Ionizing radiation is applied as the standard treatment for glioblastoma multiforme (GBM). However, radiotherapy remains merely palliative, not curative, because of the existence of glioma stem cells (GSCs), which are regarded as highly radioresistant to low linear-energy-transfer (LET) photons. Here we analyzed whether or not high-LET particles can overcome the radioresistance of GSCs. Glioma stem-like cells (GSLCs) were induced from the GBM cell line A172 in stem cell culture medium. The phenotypes of GSLCs and wild-type cells were confirmed using stem cell markers. These cells were irradiated with (60)Co gamma rays or reactor neutron beams. Under neutron-beam irradiation, high-LET proton particles can be produced through elastic scattering or nitrogen capture reaction. Radiosensitivity was assessed by a colony-forming assay, and the DNA double-strand breaks (DSBs) were assessed by a histone gamma-H2AX focus detection assay. In stem cell culture medium, GSLCs could form neurosphere-like cells and express neural stem cell markers (Sox2 and Musashi) abundantly in comparison with their parental cells. GSLCs were significantly more radioresistant to gamma rays than their parental cells, but neutron beams overcame this resistance. There were significantly fewer gamma-H2AX foci in the A172 GSLCs 24 h after irradiation with gamma rays than in their parental cultured cells, while there was no apparent difference following neutron-beam irradiation. High-LET radiation can overcome the radioresistance of GSLCs by producing unrepairable DNA DSBs. High-LET radiation therapy might have the potential to overcome GBM's resistance to X-rays in a clinical setting.

Radiation hygienization of cattle and swine slurry with high energy electron beam

International Nuclear Information System (INIS)

Skowron, Krzysztof; Olszewska, Halina; Paluszak, Zbigniew; Zimek, Zbigniew; Kałuska, Iwona; Skowron, Karolina Jadwiga

2013-01-01

The research was carried out to assess the efficiency of radiation hygienization of cattle and swine slurry of different density using the high energy electron beam based on the inactivation rate of Salmonella ssp, Escherichia coli, Enterococcus spp and Ascaris suum eggs. The experiment was conducted with use of the linear electron accelerator Elektronika 10/10 in Institute of Nuclear Chemistry and Technology in Warsaw. The inoculated slurry samples underwent hygienization with high energy electron beam of 1, 3, 5, 7 and 10 kGy. Numbers of reisolated bacteria were determined according to the MPN method, using typical microbiological media. Theoretical lethal doses, D 90 doses and hygienization efficiency of high energy electron beam were determined. The theoretical lethal doses for all tested bacteria ranged from 3.63 to 8.84 kGy and for A. suum eggs from 4.07 to 5.83 kGy. Salmonella rods turned out to be the most sensitive and Enterococcus spp were the most resistant to electron beam hygienization. The effectiveness or radiation hygienization was lower in cattle than in swine slurry and in thick than in thin one. Also the species or even the serotype of bacteria determined the dose needed to inactivation of microorganisms. - Highlights: ► The hygienic efficiency of electron beam against slurry was researched. ► The hygienization efficiency depended on the slurry characteristics and microorganism species. ► In most of the cases 7 kGy dose was sufficient for slurry hygienization. ► Dose below 1 kGy allowed for 90% elimination of microorganism population. ► The radiation hygienization is a good alternative for typical slurry treatment methods

On the origin of very-high-energy photons in astrophysics: a short introduction to acceleration and radiation physics

International Nuclear Information System (INIS)

Lemoine, M.; Pelletier, G.

2015-01-01

Powerful astrophysical sources produce non-thermal spectra of very-high-energy photons, with generic power-law distributions, through various radiative processes of charged particles, e.g., synchrotron radiation, inverse Compton processes, and hadronic interactions. Those charged particles have themselves been accelerated to ultra-relativistic energies in intense electromagnetic fields in the source. In many cases, the exact acceleration scheme is not known, but standard scenarios, such as Fermi mechanisms and reconnection processes are generally considered as prime suspects for the conversion of bulk kinetic or electromagnetic energy into a power law of supra-thermal particles. This paper proposes a short introduction to the various acceleration and radiative processes which shape the distributions of very-high-energy photons (E > 100 MeV) in astrophysics. (authors)

Universality, maximum radiation, and absorption in high-energy collisions of black holes with spin.

Science.gov (United States)

Sperhake, Ulrich; Berti, Emanuele; Cardoso, Vitor; Pretorius, Frans

2013-07-26

We explore the impact of black hole spins on the dynamics of high-energy black hole collisions. We report results from numerical simulations with γ factors up to 2.49 and dimensionless spin parameter χ=+0.85, +0.6, 0, -0.6, -0.85. We find that the scattering threshold becomes independent of spin at large center-of-mass energies, confirming previous conjectures that structure does not matter in ultrarelativistic collisions. It has further been argued that in this limit all of the kinetic energy of the system may be radiated by fine tuning the impact parameter to threshold. On the contrary, we find that only about 60% of the kinetic energy is radiated for γ=2.49. By monitoring apparent horizons before and after scattering events we show that the "missing energy" is absorbed by the individual black holes in the encounter, and moreover the individual black-hole spins change significantly. We support this conclusion with perturbative calculations. An extrapolation of our results to the limit γ→∞ suggests that about half of the center-of-mass energy of the system can be emitted in gravitational radiation, while the rest must be converted into rest-mass and spin energy.

Radiation processing of polymers with high energy electron beams: novel materials and processes

International Nuclear Information System (INIS)

Sarma, K.S.S.; Sabharwal, Sunil

2002-01-01

High-energy ionizing radiation available from electron beam (EB) accelerators has the ability to create extremely reactive species like free radicals or ions at room temperature or even at low temperature in any phase and in a variety of substrates without addition of external additives. This unique advantage of high energy has been utilized in the recent years to produce better quality materials in an environment friendly and cost-effective manner. The availability of high power and reliable EB accelerators has provided new tools to modify the materials and/or processes for a variety of applications. At BARC, a 2 MeV, 20 kW electron beam accelerator has been the nucleus of developing industrial applications of radiation processing in India for last 10 years. The focus has been on developing technologies that are of relevance to Indian socio-economic conditions and also provide economic benefits to the industry. In the areas of polymer processing industry, commercial success has already been achieved while for exploring its applications in the areas of food and agriculture and environment, technology demonstration plants are being set up. The current status of the programme, the new developments and future direction of radiation processing technology shall be presented in this paper. (author)

High linear-energy-transfer radiation can overcome radioresistance of glioma stem-like cells to low linear-energy-transfer radiation

International Nuclear Information System (INIS)

Hirota, Yuki; Kawabata, Shinji; Kuroiwa, Toshihiko; Miyatake, Shin-ichi; Masunaga, Shin-ichiro; Kondo, Natsuko; Ono, Koji; Hirakawa, Hirokazu; Yajima, Hirohiko; Fujimori, Akira

2014-01-01

Ionizing radiation is applied as the standard treatment for glioblastoma multiforme (GBM). However, radiotherapy remains merely palliative, not curative, because of the existence of glioma stem cells (GSCs), which are regarded as highly radioresistant to low linear-energy-transfer (LET) photons. Here we analyzed whether or not high-LET particles can overcome the radioresistance of GSCs. Glioma stem-like cells (GSLCs) were induced from the GBM cell line A172 in stem cell culture medium. The phenotypes of GSLCs and wild-type cells were confirmed using stem cell markers. These cells were irradiated with 60 Co gamma rays or reactor neutron beams. Under neutron-beam irradiation, high-LET proton particles can be produced through elastic scattering or nitrogen capture reaction. Radiosensitivity was assessed by a colony-forming assay, and the DNA double-strand breaks (DSBs) were assessed by a histone gamma-H2AX focus detection assay. In stem cell culture medium, GSLCs could form neurosphere-like cells and express neural stem cell markers (Sox2 and Musashi) abundantly in comparison with their parental cells. GSLCs were significantly more radioresistant to gamma rays than their parental cells, but neutron beams overcame this resistance. There were significantly fewer gamma-H2AX foci in the A172 GSLCs 24 h after irradiation with gamma rays than in their parental cultured cells, while there was no apparent difference following neutron-beam irradiation. High-LET radiation can overcome the radioresistance of GSLCs by producing unrepairable DNA DSBs. High-LET radiation therapy might have the potential to overcome GBM's resistance to X-rays in a clinical setting. (author)

Radiative polarization in high-energy storage rings

International Nuclear Information System (INIS)

Mane, S.R.

1989-01-01

Electron and positron beams circulating in high-energy storage rings become spontaneously polarized by the emission of synchrotron radiation. The asymptotic degree of polarization that can be attained is strongly affected by so-called depolarizing resonances. Detailed experimental measurements of the polarization were made SPEAR about ten years ago, but due to lack of a suitable theory only a limited theoretical fit to the data has so far been achieved. The author presents a general formalism for calculating depolarizing resonances, which has been coded into a computer program called SMILE, and use it to fit the SPEAR data. By the use of suitable approximations, the author is able to fit both higher order and nonlinear resonances, and thereby to interpret many hitherto unexplained features in the data, and to resolve a puzzle concerning the asymmetry of certain resonance widths seen in the data. 18 refs., 2 figs

Radiative recombination of highly charged ions: Enhanced rates at low energies

International Nuclear Information System (INIS)

Frank, A.; Mueller, A.; Haselbauer, J.; Schennach, S.; Spies, W.; Uwira, O.; Wagner, M.

1992-01-01

In a single-pass merged-beams experiment employing a dense cold electron target recombination of highly charged ions is studied. Unexpected high recombination rates are observed at low energies E cm in the electron-ion center-of-mass frame. In particular, theoretical estimates for radiative recombination are dramatically exceeded by the experimental recombination rates at E cm =0 eV for U 28+ and for Au 25+ ions. Considerable rate enhancement is also observed for Ar 15+ . This points to a general phenomenon which has to be interpreted as a consequence of high electron densities, low electron beam temperatures, high ion charge states and presence of strong magnetic fields. (orig.)

New self-similar radiation-hydrodynamics solutions in the high-energy density, equilibrium diffusion limit

International Nuclear Information System (INIS)

Lane, Taylor K; McClarren, Ryan G

2013-01-01

This work presents semi-analytic solutions to a radiation-hydrodynamics problem of a radiation source driving an initially cold medium. Our solutions are in the equilibrium diffusion limit, include material motion and allow for radiation-dominated situations where the radiation energy is comparable to (or greater than) the material internal energy density. As such, this work is a generalization of the classical Marshak wave problem that assumes no material motion and that the radiation energy is negligible. Including radiation energy density in the model serves to slow down the wave propagation. The solutions provide insight into the impact of radiation energy and material motion, as well as present a novel verification test for radiation transport packages. As a verification test, the solution exercises the radiation–matter coupling terms and their v/c treatment without needing a hydrodynamics solve. An example comparison between the self-similar solution and a numerical code is given. Tables of the self-similar solutions are also provided. (paper)

EFFECTS OF SPIN ON HIGH-ENERGY RADIATION FROM ACCRETING BLACK HOLES

Energy Technology Data Exchange (ETDEWEB)

O’ Riordan, Michael; Pe’er, Asaf [Physics Department, University College Cork, Cork (Ireland); McKinney, Jonathan C., E-mail: michael_oriordan@umail.ucc.ie [Department of Physics and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States)

2016-11-01

Observations of jets in X-ray binaries show a correlation between radio power and black hole spin. This correlation, if confirmed, points toward the idea that relativistic jets may be powered by the rotational energy of black holes. In order to examine this further, we perform general relativistic radiative transport calculations on magnetically arrested accretion flows, which are known to produce powerful jets via the Blandford–Znajek (BZ) mechanism. We find that the X-ray and γ -ray emission strongly depend on spin and inclination angle. Surprisingly, the high-energy power does not show the same dependence on spin as the BZ jet power, but instead can be understood as a redshift effect. In particular, photons observed perpendicular to the spin axis suffer little net redshift until originating from close to the horizon. Such observers see deeper into the hot, dense, highly magnetized inner disk region. This effect is largest for rapidly rotating black holes due to a combination of frame dragging and decreasing horizon radius. While the X-ray emission is dominated by the near horizon region, the near-infrared (NIR) radiation originates at larger radii. Therefore, the ratio of X-ray to NIR power is an observational signature of black hole spin.

Effect of high-energy radiation on the rheological characteristics and structure of liquid rubbers

International Nuclear Information System (INIS)

Govorkov, A.T.; Zaitseva, V.I.; Muryshkin, D.L.; Safonov, Yu.N.

1987-01-01

The effect of high-energy radiation (γ-radiation and accelerated electrons) on liquid polybutadiene and polyisoprene rubbers (SKD, SKD-KTR, SKN) and butyl rubber (BR) was studied by IR and EPR spectroscopy, rheoviscosimetry, and chemical analysis. Newtonian flow was conserved in the rubbers under irradiation. The activation energy of viscous flow was unchanged, evidence of an increase in the contour length of the macromolecules without significant branching and cross-linking at the initial stages of the irradiation. A quantitative relationship was established between the rubber's dynamic viscosity and the absorbed dose, and features of the structure-formation mechanism in the liquid rubbers were determined

Measurement and analysis of high energy radiation through activation detectors. Application in dosimetry

International Nuclear Information System (INIS)

Sklavenitis, L.

1967-10-01

This work is concerned with the possibility of measurement and analysis of radiation fluences within objects of small volume submitted to a high energy proton beam. The first part, consecrated to the establishment of a method of analysis, comprises a detailed study of the radiation nature and energy spectra as well as of the various dosimetry methods. In order to select a group of detectors, high energy nuclear reactions were systematically studied and for some of them cross sections were measured or calculated: for example the cross section of the reaction 11 B (p,n) 11 C between 150 and 3000 MeV and of the reaction 34 S (p,2pn) 32 P between 50 and 3000 MeV. The second part is relative to the application of the fore-mentioned analysis to radiation within a tissue equivalent phantom irradiated by 3 GeV protons. This analysis is sufficiently detailed to allow the reconstitution of the absorbed doses, the dose equivalent and, contingent on a better knowledge of the dose due to heavy particles, the quality factors. It allowed also to follow the evolution of the various dosimetric data as a function of the depth inside the phantom and to verify calculations already done by other researchers. The comparison of the measured doses and the corresponding detector activities revealed the possibility that some detectors could give directly the absorbed dose, or even the dose equivalent, by a simple activity measurement. (author) [fr

High-energy radiation from collisions of high-velocity clouds and the Galactic disc

Science.gov (United States)

del Valle, Maria V.; Müller, A. L.; Romero, G. E.

2018-04-01

High-velocity clouds (HVCs) are interstellar clouds of atomic hydrogen that do not follow normal Galactic rotation and have velocities of a several hundred kilometres per second. A considerable number of these clouds are falling down towards the Galactic disc. HVCs form large and massive complexes, so if they collide with the disc a great amount of energy would be released into the interstellar medium. The cloud-disc interaction produces two shocks: one propagates through the cloud and the other through the disc. The properties of these shocks depend mainly on the cloud velocity and the disc-cloud density ratio. In this work, we study the conditions necessary for these shocks to accelerate particles by diffusive shock acceleration and we study the non-thermal radiation that is produced. We analyse particle acceleration in both the cloud and disc shocks. Solving a time-dependent two-dimensional transport equation for both relativistic electrons and protons, we obtain particle distributions and non-thermal spectral energy distributions. In a shocked cloud, significant synchrotron radio emission is produced along with soft gamma rays. In the case of acceleration in the shocked disc, the non-thermal radiation is stronger; the gamma rays, of leptonic origin, might be detectable with current instruments. A large number of protons are injected into the Galactic interstellar medium, and locally exceed the cosmic ray background. We conclude that under adequate conditions the contribution from HVC-disc collisions to the galactic population of relativistic particles and the associated extended non-thermal radiation might be important.

Higgs radiation off top particles in high-energy e+e- colliders

International Nuclear Information System (INIS)

Djouadi, A.; Technische Hochschule Aachen; Kalinowski, J.; Zerwas, P.M.

1991-10-01

Higgs particles can be radiated off heavy top quarks which will be produced copiously in high energy e + e - colliders. This process can be used to measure the Higgs-top quark coupling. We present the cross section for the production of Higgs bosons in the Standard Model. In addition we have studied the production of neutral and charged Higgs particles in association with heavy fermions in the Minimal Supersymmetric Standard Model. (orig.)

New apparatus with high radiation energy between 320-460 nm: physical description and dermatological applications

International Nuclear Information System (INIS)

Mutzhas, M.F.; Holzle, E.; Hofmann, C.; Plewig, G.

1981-01-01

A new apparatus (UVASUN 5000) is presented with high-radiation energy between 320 to 460 nm. The measureable energy below 320 nm was shown to be many orders of magnitude too low to produce erythema. The radiator is a specially developed source for high uv-A intensity, housing a quartz bulb with a mixture of argon, mercury and metal-halides. At a skin-target distance of 0.2 m the size of the irradiated area is 0.35 x 0.35 m, and the measured mean uv-A intensity is about 1400 W. m-2 (140 mW . cm-2). The uv-A energy in the range of 320 to 400 nm is about 84% of the total radiation energy. Effects of very high doses of uv-A on human skin were studied. Following single uv-a applications the minimal tanning dose uv-A (MTD) and the immediate pigment darkening (IPD) dose of uv-A were established. The calculated IPD threshold time was 1.8 min at 0.2 m. Repeated exposure to this uv-A delivering system yields long lasting dark brown skin pigmentation without any clinical or histological signs of sunburn (uv-B) damage, epidermal hyperplasia or thickening of the stratum corneum. The instrument was also successfully used for photo-patch testing and reproduction of skin lesions of polymorphous light eruption. Minimal therapeutic results were seen in the phototherapy of vitiligo and inflammatory acne

Ferrites based infrared radiation coatings with high emissivity and high thermal shock resistance and their application on energy-saving kettle

International Nuclear Information System (INIS)

Zhang, Jianyi; Fan, Xi’an; Lu, Lei; Hu, Xiaoming; Li, Guangqiang

2015-01-01

Highlights: • The ferrites based infrared radiation coating was prepared by HVOF for the first time. • The infrared radiation coatings were applied firstly on the household kettle. • The bonding strength between the coating and substrate could reach 30.7 MPa. • The coating kept intact when cycle reached 27 by quenching from 1000 °C using water. • The energy-saving efficiency of the kettle with coating could reach 30.5%. - Abstract: Starting from Fe 2 O 3 , MnO 2 , Co 2 O 3 and NiO powders, the ferrites based infrared radiation coatings with high emissivity and high thermal shock resistance were successfully prepared on the surface of carbon steel by high velocity oxy-fuel spraying (HVOF). The coating thickness was about 120–150 μm and presented a typical flat lamellar structure. The coating surface was rough and some submicron grade grains distributed on it. The infrared emissivity of the ferrites based coating by HVOF was over 0.74 in 3–20 μm waveband at 800 °C, which was obviously higher than that of the coating by brushing process in the short waveband. The bonding strength was 30.7 MPa between the coating and substrate, which was five times more than that of conventional coatings by brushing process. The combined effect of the superior bonding strength, typical lamellar structure, pre-existing microcracks and newly generated pores made the cycle times reach 27 when the coating samples were quenched from 1000 °C using water. Lastly, the infrared radiation coatings were applied on the underside of household kettle, and the energy-saving efficiency could reach 30.5%. The ferrites based infrared radiation coatings obtained in this work are good candidates for saving energy in the field of cookware and industrial high temperature furnace

A Self-Powered Thin-Film Radiation Detector Using Intrinsic High-Energy Current (HEC) (Author’s Final Version)

Science.gov (United States)

2016-09-08

of electromagnetic 85 pulse effects on cables and electrical devices4 and as a self - powered detector for in-core neutron flux measurement in nuclear...AFCEC-CX-TY-TP-2016-0003 A SELF - POWERED THIN-FILM RADIATION DETECTOR USING INTRINSIC HIGH-ENERGY CURRENT (HEC) (AUTHOR’S FINAL VERSION...14 -- 5 Oct 15 A self - powered thin-film radiation detector using intrinsic high-energy current (HEC) (Author’s Final Version) FA8051-15-P-0010

Development of transmission dose estimation algorithm for in vivo dosimetry in high energy radiation treatment

International Nuclear Information System (INIS)

Yun, Hyong Geun; Shin, Kyo Chul; Hun, Soon Nyung; Woo, Hong Gyun; Ha, Sung Whan; Lee, Hyoung Koo

2004-01-01

In vivo dosimetry is very important for quality assurance purpose in high energy radiation treatment. Measurement of transmission dose is a new method of in vivo dosimetry which is noninvasive and easy for daily performance. This study is to develop a tumor dose estimation algorithm using measured transmission dose for open radiation field. For basic beam data, transmission dose was measured with various field size (FS) of square radiation field, phantom thickness (Tp), and phantom chamber distance (PCD) with a acrylic phantom for 6 MV and 10 MV X-ray. Source to chamber distance (SCD) was set to 150 cm. Measurement was conducted with a 0.6 cc Farmer type ion chamber. By using regression analysis of measured basic beam data, a transmission dose estimation algorithm was developed. Accuracy of the algorithm was tested with flat solid phantom with various thickness in various settings of rectangular fields and various PCD. In our developed algorithm, transmission dose was equated to quadratic function of log(A/P) (where A/P is area-perimeter ratio) and the coefficients of the quadratic functions were equated to tertiary functions of PCD. Our developed algorithm could estimate the radiation dose with the errors within ±0.5% for open square field, and with the errors within ±1.0% for open elongated radiation field. Developed algorithm could accurately estimate the transmission dose in open radiation fields with various treatment settings of high energy radiation treatment. (author)

Interaction of Repetitively Pulsed High Energy Laser Radiation With Matter

Science.gov (United States)

Hugenschmidt, Manfred

1986-10-01

The paper is concerned with laser target interaction processes involving new methods of improving the overall energy balance. As expected theoretically, this can be achieved with high repetition rate pulsed lasers even for initially highly reflecting materials, such as metals. Experiments were performed by using a pulsed CO2 laser at mean powers up to 2 kW and repetition rates up to 100 Hz. The rates of temperature rise of aluminium for example were thereby increased by lore than a factor of 3 as compared to cw-radiation of comparable power density. Similar improvements were found for the overall absorptivities that were increased by this method by more than an order of magnitude.

Practical neutron dosimetry at high energies

International Nuclear Information System (INIS)

McCaslin, J.B.; Thomas, R.H.

1980-10-01

Dosimetry at high energy particle accelerators is discussed with emphasis on physical measurements which define the radiation environment and provide an immutable basis for the derivation of any quantities subsequently required for risk evaluation. Results of inter-laboratory dosimetric comparisons are reviewed and it is concluded that a well-supported systematic program is needed which would make possible detailed evaluations and inter-comparisons of instruments and techniques in well characterized high energy radiation fields. High-energy dosimetry is so coupled with radiation transport that it is clear their study should proceed concurrently

High Energy Density Laboratory Astrophysics

CERN Document Server

Lebedev, Sergey V

2007-01-01

During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

Effect of high energy β-radiation and addition of triallyl isocyanurate on the selected properties of polylactide

Energy Technology Data Exchange (ETDEWEB)

Malinowski, Rafał, E-mail: malinowskirafal@gmail.com

2016-06-15

Comparison of some changes occurring in polylactide (PLA) due to high energy β-radiation and addition of triallyl isocyanurate (TAIC) was the main objective of the present study. It was found that irradiation of PLA by high energy β-radiation causes essential changes in its properties, that undergoes mainly degradation, to form a porous structure. The PLA degradation can be diminished by introduction into the polymer matrix of a low-molecular mass multifunctional compound like TAIC. Upon the electron radiation, effective crosslinking of PLA by TAIC occurs. Application of TAIC favorably influences hindering of the PLA degradation or, when the doses are very large, diminishes worsening of the PLA functional qualities. It was also found that the optimum crosslinking of PLA is obtained when the electron radiation doses of the range of 40–200 kGy are applied and the amount of TAIC equal 3–5 wt% is used.

Development of High Energy Particle Detector for the Study of Space Radiation Storm

Directory of Open Access Journals (Sweden)

Gyeong-Bok Jo

2014-09-01

Full Text Available Next Generation Small Satellite-1 (NEXTSat-1 is scheduled to launch in 2017 and Instruments for the Study of Space Storm (ISSS is planned to be onboard the NEXTSat-1. High Energy Particle Detector (HEPD is one of the equipment comprising ISSS and the main objective of HEPD is to measure the high energy particles streaming into the Earth radiation belt during the event of a space storm, especially, electrons and protons, to obtain the flux information of those particles. For the design of HEPD, the Geometrical Factor was calculated to be 0.05 to be consistent with the targets of measurement and the structure of telescope with field of view of 33.4° was designed using this factor. In order to decide the thickness of the detector sensor and the classification of the detection channels, a simulation was performed using GEANT4. Based on the simulation results, two silicon detectors with 1 mm thickness were selected and the aluminum foil of 0.05 mm is placed right in front of the silicon detectors to shield low energy particles. The detection channels are divided into an electron channel and two proton channels based on the measured LET of the particle. If the measured LET is less than 0.8 MeV, the particle belongs to the electron channel, otherwise it belongs to proton channels. HEPD is installed in the direction of 0°,45°,90° against the along-track of a satellite to enable the efficient measurement of high energy particles. HEPD detects electrons with the energy of 0.1 MeV to several MeV and protons with the energy of more than a few MeV. Thus, the study on the dynamic mechanism of these particles in the Earth radiation belt will be performed.

Observations of visual sensations produced by Cerenkov radiation from high-energy electrons

International Nuclear Information System (INIS)

Steidley, K.D.; Eastman, R.M.; Stabile, R.J.

1989-01-01

Ten cancer patients whose eyes were therapeutically irradiated with 6-18 MeV electrons reported visual light sensations. Nine reported seeing blue light and one reported seeing white light. Controls reported seeing no light. Additionally, tests with patients ruled out the x-ray contamination of the electron beam as being important. The photon yield due to Cerenkov radiation produced by radium and its daughters for both electrons and gamma rays was calculated; it was found to account for a turn-of-the-century human observation of the radium phosphene. We conclude that the dominant mechanism of this phosphene is Cerenkov radiation, primarily from betas. From our own patient data, based on the color seen and the Cerenkov production rates, we conclude that the dominant mechanism is Cerenkov radiation and that high-energy electrons are an example of particle induced visual sensations

Distributed Optical Fiber Radiation and Temperature Sensing at High Energy Accelerators and Experiments

CERN Document Server

AUTHOR|(CDS)2090137; Brugger, Markus

The aim of this Thesis is to investigate the feasibility of a distributed optical fiber radiation sensing system to be used at high energy physics accelerators and experiments where complex mixed-field environments are present. In particular, after having characterized the response of a selection of radiation sensitive optical fibers to ionizing radiation coming from a 60Co source, the results of distributed optical fiber radiation measurements in a mixed-field environment are presented along with the method to actually estimate the dose variation. This study demonstrates that distributed optical fiber dosimetry in the above mentioned mixed-field radiation environment is feasible, allowing to detect dose variations of about 10-15 Gy with a 1 m spatial resolution. The proof of principle has fully succeeded and we can now tackle the challenge of an industrial installation taking into account that some optimizations need to be done both on the control unit of the system as well as on the choice of the sensing f...

Paradigm Shift in Radiation Biology/Radiation Oncology—Exploitation of the “H2O2 Effect” for Radiotherapy Using Low-LET (Linear Energy Transfer Radiation such as X-rays and High-Energy Electrons

Directory of Open Access Journals (Sweden)

Yasuhiro Ogawa

2016-02-01

Full Text Available Most radiation biologists/radiation oncologists have long accepted the concept that the biologic effects of radiation principally involve damage to deoxyribonucleic acid (DNA, which is the critical target, as described in “Radiobiology for the Radiologist”, by E.J. Hall and A.J. Giaccia [1]. Although the concepts of direct and indirect effects of radiation are fully applicable to low-LET (linear energy transfer radioresistant tumor cells/normal tissues such as osteosarcoma cells and chondrocytes, it is believed that radiation-associated damage to DNA does not play a major role in the mechanism of cell death in low-LET radiosensitive tumors/normal tissues such as malignant lymphoma cells and lymphocytes. Hall and Giaccia describe lymphocytes as very radiosensitive, based largely on apoptosis subsequent to irradiation. As described in this review, apoptosis of lymphocytes and lymphoma cells is actually induced by the “hydrogen peroxide (H2O2 effect”, which I propose in this review article for the first time. The mechanism of lymphocyte death via the H2O2 effect represents an ideal model to develop the enhancement method of radiosensitivity for radiation therapy of malignant neoplasms. In terms of imitating the high radiosensitivity of lymphocytes, osteosarcoma cells (representative of low-LET radioresistant cells might be the ideal model for indicating the conversion of cells from radioresistant to radiosensitive utilizing the H2O2 effect. External beam radiation such as X-rays and high-energy electrons for use in modern radiotherapy are generally produced using a linear accelerator. We theorized that when tumors are irradiated in the presence of H2O2, the activities of anti-oxidative enzymes such as peroxidases and catalase are blocked and oxygen molecules are produced at the same time via the H2O2 effect, resulting in oxidative damage to low-LET radioresistant tumor cells, thereby rendering them highly sensitive to irradiation. In this

Radiation effects on materials in high-radiation environments

International Nuclear Information System (INIS)

Weber, W.J.; Mansur, L.K.; Clinard, F.W. Jr.; Parkin, D.M.

1991-01-01

A workshop on Radiation Effects on Materials in High-Radiation Environments was held in Salt Lake City, Utah (USA) from August 13 to 15, 1990 under the auspices of the Division of Materials Sciences, Office of Basic Energy Sciences, US Department of Energy. The workshop focused on ceramics, alloys, and intermetallics and covered research needs and capabilities, recent experimental data, theory, and computer simulations. It was concluded that there is clearly a continuing scientific and technological need for fundamental knowledge on the underlying causes of radiation-induced property changes in materials. Furthermore, the success of many current and emerging nuclear-related technologies critically depend on renewed support for basic radiation-effects research, irradiation facilities, and training of scientists. The highlights of the workshop are reviewed and specific recommendations are made regarding research needs. (orig.)

Application of TSEE characteristics to high energy radiation dosimetry around an electron linear accelerator

International Nuclear Information System (INIS)

Yamamoto, T.; Nakasaku, S.; Kawanishi, M.

1986-01-01

The response of the exoelectron dosemeter to the absorbed dose has been investigated with the LiF sample irradiated with high energy electrons from a linear accelerator and γ rays from a 60 Co source. The energy absorbed in the thin surface layer, which can be related to the origins of exoelectron emission, is, in general, smaller than the energy liberated there by primary radiation. In this paper the surface dose is calculated by the Monte Carlo Code EGS4. It is pointed out that the air layer in front of the sample also plays an important role by supplying secondary electrons to the surface region of the sample. The emission density of exoelectrons from a LiF single crystal for unit absorbed dose is found to be 5 x 10 4 electrons.cm -2 .Gy -1 , and nearly constant independent of the low LET radiation type. (author)

High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

Science.gov (United States)

Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

2018-04-01

High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

International Nuclear Information System (INIS)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon

2002-01-01

High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of As Low As Reasonably Achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons . This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients are treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Polo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions 30cm x 30cm x 20cm. The anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is

Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon [Yonsei Univ., Seoul (Korea, Republic of)

2002-03-15

High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of As Low As Reasonably Achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons . This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients are treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Polo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions 30cm x 30cm x 20cm. The anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is

Origin of life: hypothesized roles of high-energy electrical discharges, infrared radiation, thermosynthesis and pre-photosynthesis.

Science.gov (United States)

Trevors, J T

2012-12-01

The hypothesis is proposed that during the organization of pre-biotic bacterial cell(s), high-energy electrical discharges, infrared radiation (IR), thermosynthesis and possibly pre-photosynthesis were central to the origin of life. High-energy electrical discharges generated some simple organic molecules available for the origin of life. Infrared radiation, both incoming to the Earth and generated on the cooling Earth with day/night and warming/cooling cycles, was a component of heat engine thermosynthesis before enzymes and the genetic code were present. Eventually, a primitive forerunner of photosynthesis and the capability to capture visible light emerged. In addition, the dual particle-wave nature of light is discussed from the perspective that life requires light acting both as a wave and particle.

High-altitude cosmic ray neutrons: probable source for the high-energy protons of the earth's radiation belts

International Nuclear Information System (INIS)

Hajnal, F.; Wilson, J.

1992-01-01

'Full Text:' Several High-altitude cosmic-ray neutron measurements were performed by the NASA Ames Laboratory in the mid-to late-1970s using airplanes flying at about 13km altitude along constant geomagnetic latitudes of 20, 44 and 51 degrees north. Bonner spheres and manganese, gold and aluminium foils were used in the measurements. In addition, large moderated BF-3 counters served as normalizing instruments. Data analyses performed at that time did not provide complete and unambiguous spectral information and field intensities. Recently, using our new unfolding methods and codes, and Bonner-sphere response function extensions for higher energies, 'new' neutron spectral intensities were obtained, which show progressive hardening of neutron spectra as a function of increasing geomagnetic latitude, with substantial increases in the energy region iron, 1 0 MeV to 10 GeV. For example, we found that the total neutron fluences at 20 and 51 degrees magnetic north are in the ratio of 1 to 5.2 and the 10 MeV to 10 GeV fluence ratio is 1 to 18. The magnitude of these ratios is quite remarkable. From the new results, the derived absolute neutron energy distribution is of the correct strength and shape for the albedo neutrons to be the main source of the high-energy protons trapped in the Earth's inner radiation belt. In addition, the results, depending on the extrapolation scheme used, indicate that the neutron dose equivalent rate may be as high as 0.1 mSv/h near the geomagnetic north pole and thus a significant contributor to the radiation exposures of pilots, flight attendants and the general public. (author)

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

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)

Final Technical Report Radiation Hard Tight Pitch GaInP SPAD Arrays for High Energy Physics

Energy Technology Data Exchange (ETDEWEB)

Harmon, Eric

2018-01-26

The specialized photodetectors used in high energy physics experiments often need to remain extremely sensitive for years despite radiation induced damage caused by the constant bombardment of high energy particles. To solve this problem, LightSpin Technologies, Inc. in collaboration with Prof. Bradley Cox and the University of Virginia is developing radiation-hard GaInP photodetectors which are projected to be extraordinarily radiation hard, theoretically capable of withstanding a 100,000-fold higher radiation dose than silicon. In this Phase I SBIR project, LightSpin investigated the performance and radiation hardness of fifth generation GaInP SPAD arrays. These fifth generation devices used a new planar processing approach that enables very tight pitch arrays to be produced. High performance devices with SPAD pitches of 11, 15, and 25 μm were successfully demonstrated, which greatly increased the dynamic range and maximum count rate of the devices. High maximum count rates are critical when considering radiation hardness, since radiation damage causes a proportional increase in the dark count rate, causing SPAD arrays with low maximum count rates (large SPAD pitches) to fail. These GaInP SPAD array Photomultiplier Chips™ were irradiated with protons, electrons, and neutrons. Initial irradiation results were disappointing, with the post-irradiation devices exhibiting excessively high dark currents. The degradation was traced to surface leakage currents that were largely eliminated through the use of trenches etched around the exterior of the Photomultiplier Chip™ (not between SPAD elements). A second round of irradiations on Photomultiplier Chips™ with trenches proved substantially more successful, with post-irradiation dark currents remaining relatively low, though dark count rates were observed to increase at the highest doses. Preliminary analysis of the post-irradiation devices is promising … many of the irradiated Photomultiplier Chips™ still

High energy photon reference for radiation protection: technical design of the LINAC beam and ionization chambers; and calculation of monoenergetic conversion coefficients

Directory of Open Access Journals (Sweden)

Dusciac D.

2016-01-01

Full Text Available In this work, we present the results of the first part of a research project aimed at offering a complete response to dosimeters providers and nuclear physicists’ demands for high-energy (6 – 9 MeV photon beams for radiation protection purposes. Classical facilities allowing the production of high-energy photonic radiation (proton accelerators, nuclear reactors are very rare and need large investment for development and use. A novel solution is proposed, consisting in the use of a medical linear accelerator, allowing a significant decrease of all costs.Using Monte Carlo simulations (MCNP5 and PENELOPE codes, a specifically designed electron-photon conversion target allowing for obtaining a high energy photon beam (with an average energy weighted by fluence of about 6 MeV has been built for radiation protection purposes. Due to the specific design of the target, this “realistic” radiation protection high-energy photon beam presents a uniform distribution of air kerma rate at a distance of 1 m, over a 30 × 30 cm2 surface. Two graphite cavity ionizing chambers for ionometric measurements have been built. For one of these chambers, the charge collection volume has been measured allowing for its use as a primary standard. The second ionizing chamber is used as a transfer standard; as such it has been calibrated in a 60Co beam, and in the high energy photon beam for radiation protection.The measurements with these ionizing chambers allowed for an evaluation of the air kerma rate in the LINAC based high-energy photon beam for radiation protection: the values cover a range between 36 mGy/h and 210 mGy/h, compatible with radiation protection purposes.Finally, using Monte Carlo simulations, conversion coefficients from air kerma to dose equivalent quantities have been calculated in the range between 10 keV and 22.4 MeV, for the spectral distribution of the fluence corresponding to the beam produced by the linear accelerator of the LNE-LNHB.

Split energy level radiation detection

International Nuclear Information System (INIS)

Barnes, G.T.

1986-01-01

This patent describes an energy discriminating radiation detector comprising: (a) a first element comprising a first material of a kind which is preferentially responsive to penetrative radiation of a first energy range; (b) a second element comprising a second material different in kind from the first material and of a kind which is preferentially responsive to penetrative radiation of second energy range extending higher than the first energy range. The element is positioned to receive radiation which has penetrated through a portion of the first element; and (c) a filter of penetrative radiation interposed between the first and second elements

Radiation-hard Silicon Photonics for Future High Energy Physics Experiments

CERN Document Server

AUTHOR|(CDS)2089774; Troska, Jan

Collisions of proton beams in the Large Hadron Collider at CERN produce very high radiation levels in the innermost parts of the particle detectors and enormous amounts of measurement data. Thousands of radiation-hard optical links based on directly-modulated laser diodes are thus installed in the particle detectors to transmit the measurement data to the processing electronics. The radiation levels in the innermost regions of future particle detectors will be much higher than they are now. Alternative solutions to laser-based radiation-hard optical links have to be found since the performance of laser diodes decreases beyond the operation margin of the system when irradiated to sufficiently high radiation levels. Silicon Photonics (SiPh) is currently being investigated as a promising alternative technology. First tests have indeed shown that SiPh Mach-Zehnder modulators (MZMs) are relatively insensitive to a high neutron fluence. However, they showed a strong degradation when exposed to ionizing radiation. ...

Preparation and characterization of intrinsically coloured polymers using high energy radiation induced processes

International Nuclear Information System (INIS)

Guthrie, J.T.

1978-07-01

Information on the development in research is given in the utilization of high energy radiation sources in polymerizations and on polymer characterization in the following three areas: studies on the nitrile-styrene system, studies on the radiation induced polymerization of 2-vinyl anthraquinone and the graft polymerization of vinyl monomers onto cellulose in the DMSO/HCHO/cellulose system. Within the framework of research in radiation induced polymerization, samples of 2-vinyl anthraquinone were subjected to X-ray diffraction and e.s.r. examinations and the kinetics and mechanism of γ-ray induced solution polymerization of 2-vinyl anthraquinone in methylene chloride and dimethyl sulfoxide was investigated. Methylene chloride was found to be an efficient solvent for poly(2-vinyl anthraquinone). The rate of polymerization in methylene chloride was 10 3 times greater than that obtained using dimethyl sulfoxide as solvent

Design of two digital radiation tolerant integrated circuits for high energy physics experiments data readout

CERN Document Server

Bonacini, Sandro

2003-01-01

High Energy Physics research (HEP) involves the design of readout electron- ics for its experiments, which generate a high radiation ¯eld in the detectors. The several integrated circuits placed in the future Large Hadron Collider (LHC) experiments' environment have to resist the radiation and carry out their normal operation. In this thesis I will describe in detail what, during my 10-months partic- ipation in the digital section of the Microelectronics group at CERN, I had the possibility to work on: - The design of a radiation-tolerant data readout digital integrated cir- cuit in a 0.25 ¹m CMOS technology, called \\the Kchip", for the CMS preshower front-end system. This will be described in Chapter 3. - The design of a radiation-tolerant SRAM integrated circuit in a 0.13 ¹m CMOS technology, for technology radiation testing purposes and fu- ture applications in the HEP ¯eld. The SRAM will be described in Chapter 4. All the work has carried out under the supervision and with the help of Dr. Kostas Klouki...

Radiation protection metrology at a high-energy neutron therapy facility

International Nuclear Information System (INIS)

Bonnett, D.E.; Sherwin, A.G.; More, B.R.

1991-01-01

A radiation protection survey has been carried out at a high-energy neutron therapy facility using a combination of different detectors and counters. Included in the survey were measurements with a tissue equivalent proportional counter (TEPC), a rem meter, a large volume ionisation chamber (LVI) and a Geiger counter. Dose equivalent rates, normalised to a proton beam current of 25 μA, of between 1 μSv.h -1 and 0.7 Sv.h -1 were recorded depending on the location. In general the results confirm the tendency of the rem meter to over-read in fields consisting mainly of low energy neutrons and illustrate the advantages of the diagnostic and gamma discriminating properties of the TEPC. The LVI-Geiger system was found to be the least favourable combination of dosemeters, substantially under-reading and being unable to estimate the neutron dose rate at levels below about 32 μGy.h -1 . (author)

TEA HF laser with a high specific radiation energy

Science.gov (United States)

Puchikin, A. V.; Andreev, M. V.; Losev, V. F.; Panchenko, Yu. N.

2017-01-01

Results of experimental studies of the chemical HF laser with a non-chain reaction are presented. The possibility of the total laser efficiency of 5 % is shown when a traditional C-to-C pumping circuit with the charging voltage of 20-24 kV is used. It is experimentally shown that the specific radiation output energy of 21 J/l is reached at the specific pump energy of 350 J/l in SF6/H2 = 14/1 mixture at the total pressure of 0.27 bar.

Radiation hardness of Ce-doped sol-gel silica fibers for high energy physics applications.

Science.gov (United States)

Cova, Francesca; Moretti, Federico; Fasoli, Mauro; Chiodini, Norberto; Pauwels, Kristof; Auffray, Etiennette; Lucchini, Marco Toliman; Baccaro, Stefania; Cemmi, Alessia; Bártová, Hana; Vedda, Anna

2018-02-15

The results of irradiation tests on Ce-doped sol-gel silica using x- and γ-rays up to 10 kGy are reported in order to investigate the radiation hardness of this material for high-energy physics applications. Sol-gel silica fibers with Ce concentrations of 0.0125 and 0.05 mol. % are characterized by means of optical absorption and attenuation length measurements before and after irradiation. The two different techniques give comparable results, evidencing the formation of a main broad radiation-induced absorption band, peaking at about 2.2 eV, related to radiation-induced color centers. The results are compared with those obtained on bulk silica. This study reveals that an improvement of the radiation hardness of Ce-doped silica fibers can be achieved by reducing Ce content inside the fiber core, paving the way for further material development.

Measurement of continuous x-radiation and determination of the energy distribution function of high-energy electrons from an ECR plasma

International Nuclear Information System (INIS)

Bernhardi, K.

1980-01-01

Investigations were made on the x-radiation emitted by a plasma. The methods applied here represent a further development of experimental and numerical methods used hitherto for determining the bremsstrahlung emitted by a plasma, and makes possible a more precise determination of the high-energy electron component of a plasma

Measurements of internal stresses in bond coating using high energy x-rays from synchrotron radiation source

CERN Document Server

Suzuki, K; Akiniwa, Y; Nishio, K; Kawamura, M; Okado, H

2002-01-01

Thermal barrier coating (TBC) techniques enable high temperature combustion of turbines made of Ni-base alloy. TBC is made of zirconia top coating on NiCoCrAlY bond coating. The internal stresses in the bond coating play essential role in the delamination or fracture of TBC in service. With the X-rays from laboratory equipments, it is impossible to measure nondestructively the internal stress in the bond coating under the top coating. synchrotron radiations with a high energy and high brightness have a large penetration depth as compared with laboratory X-rays. Using the high energy X-rays from the synchrotron radiation, it is possible to measure the internal stress in the bond coating through the top coating. In this study, the furnace, which can heat a specimen to 1473 K, was developed for the stress measurement of the thermal barrier coatings. The internal stresses in the bond coating were measured at the room temperature, 773 K, 1073 K and 1373 K by using the 311 diffraction from Ni sub 3 Al with about 73...

Measurement assurance studies of high-energy electron and photon dosimetry in radiation-therapy applications

Energy Technology Data Exchange (ETDEWEB)

Ehrlich, M; Soares, C G [National Bureau of Standards, Washington, DC (USA)

1981-08-01

This is a brief review of surveys on the dosimetry of radiation-therapy beams by the National Bureau of Standards (NBS). Covered are the NBS ferrous-sulfate (Fricke) dosimetry service, a recently completed survey carried out with thermoluminescence dosimeters (TLD) on the dosimetry in cobalt-60 teletherapy beams, and plans for a TLD survey of dosimetry in high-energy bremsstrahlung beams.

Measurement assurance studies of high-energy electron and photon dosimetry in radiation-therapy applications

International Nuclear Information System (INIS)

Ehrlich, M.; Soares, C.G.

1981-01-01

This is a brief review of surveys on the dosimetry of radiation-therapy beams by the National Bureau of Standards (NBS). Covered are the NBS ferrous-sulfate (Fricke) dosimetry service, a recently completed survey carried out with thermoluminescence dosimeters (TLD) on the dosimetry in cobalt-60 teletherapy beams, and plans for a TLD survey of dosimetry in high-energy bremsstrahlung beams. (author)

Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

Science.gov (United States)

Schroeder, J L; Thomson, W; Howard, B; Schell, N; Näslund, L-Å; Rogström, L; Johansson-Jõesaar, M P; Ghafoor, N; Odén, M; Nothnagel, E; Shepard, A; Greer, J; Birch, J

2015-09-01

We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

Radiation spectra of high-energy electrons in monocrystals of various thickness and orientation

International Nuclear Information System (INIS)

Avakyan, R.O.; Agan'yants, A.O.; Akopov, N.Z.; Vartanov, Yu.A.; Vartapetyan, G.A.; Lebedev, A.N.; Mirzoyan, R.M.; Taroyan, S.P.; Danagulyan, S.S.

1982-01-01

Yield of photons with energies 20-200 MeV at motion of the 4.7 GeV electron beam in parallel to the axis of a diamond crystal exceeds substantially the corresponding yield from a disoriented target. A similarity is observed in the radiation spectra within the crystal thickness range of 100- 610 mkm. The radiation yield is suppressed at certain energies of the γ quanta [ru

Measurement of solar energy radiation in Abu Dhabi, UAE

Energy Technology Data Exchange (ETDEWEB)

Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi, P.O. Box 2533 (United Arab Emirates)

2009-04-15

This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 N, 54.45 E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m{sup 2}, respectively. The highest one-minute average daily solar radiation was 1041 W/m{sup 2}. Yearly average daily energy input was 18.48 MJ/m{sup 2}/day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture. (author)

Measurement of solar energy radiation in Abu Dhabi, UAE

International Nuclear Information System (INIS)

Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A.

2009-01-01

This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 deg. N, 54.45 deg. E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m 2 , respectively. The highest one-minute average daily solar radiation was 1041 W/m 2 . Yearly average daily energy input was 18.48 MJ/m 2 /day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture

Measurement of NdFeB permanent magnets demagnetization induced by high energy electron radiation

Energy Technology Data Exchange (ETDEWEB)

Temnykh, Alexander B. [Wilson Lab, Cornell University, LEPP, Ithaca, NY 14850 (United States)], E-mail: abt6@cornell.edu

2008-03-11

Demagnetization of NdFeB permanent magnets has been measured as function of radiation dose induced by high energy electrons. The magnet samples were of different intrinsic coercive forces, {approx_equal}12 and {approx_equal}20KOe, dimensions and direction of magnetization. 5 GeV electron beam from 12 GeV Cornell Synchrotron was used as a radiation source. A calorimetric technique was employed for radiation dose measurement. Results indicated that depending on the sample intrinsic coercive force, shape and direction of magnetization the radiation dose causing 1% of demagnetization of the sample varies from 0.0765{+-}0.005Mrad to 11.3{+-}3.0Mrad, i.e., by more than a factor of 100. Experimental data analysis revealed that demagnetization of the given sample induced by radiation is strongly correlated with the sample demagnetizing temperature. This correlation was approximated by an exponential function with two parameters obtained from the data fitting. The function can be used to predict the critical radiation dose for permanent magnet assemblies like undulator magnets based on its demagnetizing temperature. The latter (demagnetization temperature) can be determined at the design stage from 3-D magnetic modeling and permanent magnet material properties.

Radiation versus radiation: nuclear energy in perspective

International Nuclear Information System (INIS)

Gonzalez, A.J.; Anderer, J.

1989-01-01

This paper seeks to provide a proper perspective on radiation exposures from nuclear energy. Instead of comparing these exposures with other pollutants, natural and man-made, it assesses the radiation doses that result from the human environment and from the entire fuel cycle associated with nuclear generated electricity. It explores radiation versus radiation, not only in terms of absolute levels but, more importantly, of the enormous variability characterizing many radiation sources. The quantitative findings and their implications are meant to contribute to a balanced understanding of the radiological impact of nuclear energy, and so to help to bridge the information gap that is perceived to exist on this issue. The 1988 Unscear report and its seven scientific annexes provide an authoritative and dispassionate factual basis for examining radiation levels from all sources, natural and man-made. It is the main source for this paper. (author)

Toward improvements of the education concerning radiation, radioactivity, and nuclear energy in high schools in Japan

International Nuclear Information System (INIS)

Matsuura, Tatsuo

1996-01-01

Despite the high scientific and technical level of research and practical applications of radiation, radioactivity, and nuclear energy in Japan, the level of education concerning these matters at primary school and junior and high schools seems to be considerably behind the world, according to a recent comparative survey among six European countries and Japan. It has also been found that the description of these matters in current textbooks of science and social studies in senior high schools in Japan is generally not satisfactory, both in scope and in correctness. There are many reasons for this observation. One is the fact that many Japanese people including writers of textbooks have an excessive fear for radiation and radioactivity, and consequently are critical of the use of nuclear energy. Another is that Japanese teachers also have similar feeling and tend to avoid teaching about such controversial subject. This comes from the educational policy of Monbusho, Ministry of Education, Science and Culture; the nuclear-related matters are not being given an appropriate educational position, despite their importance in the national energy policy determined by the Atomic Energy Commission of Japan. In addition, there are several unfortunate educational circumstances. These include, limitations of hours of teaching allotted to the subject of science, the system of choosing curricula among several menus in the subject, the shortage of experimental instruments available in classroom, the severe safety regulation in handling even a very small amount of radioactivity, extraordinary fear for radiation and radioactivity by students, teachers, and their supervisors, the rare appearance of these topics in the problems at the entrance examination of universities. This paper discusses various ways to correct the situation and reports on our recent activities for improving means of education such as textbooks and the official guidelines. (J.P.N.)

Research activities on dosimetry for high energy neutrons

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2003-03-01

The external dosimetry research group of JAERI has been calculating dose conversion coefficients for high-energy radiations using particle transport simulation codes. The group has also been developing radiation dose measurement techniques for high-energy neutrons in collaboration with some university groups. (author)

Prototypes of Self-Powered Radiation Detectors Employing Intrinsic High-Energy Current (HEC) (POSTPRINT)

Science.gov (United States)

2016-01-01

neutron sensi- tivities of a Pt self - powered detector ,” IEEE Trans. Nucl. Sci. 25, 292–295 (1978). 6T. A. Dellin, R. E. Huddleston, and C. J...Gamma-sensitive self - powered detectors and their use for in-core flux -mapping,” IEEE Trans. Nucl. Sci. 28, 752–757 (1981). 9E. A. Burke and J. Wall...AFCEC-CX-TY-TP-2016-0006 PROTOTYPES OF SELF - POWERED RADIATION DETECTORS EMPLOYING INTRINSIC HIGH-ENERGY CURRENT (HEC) (POSTPRINT) Piotr

Radiation effects of high and low doses

International Nuclear Information System (INIS)

El-Naggar, A.M.

1998-01-01

The extensive proliferation of the uses and applications of atomic and nuclear energy resulted in possible repercussions on human health. The prominent features of the health hazards that may be incurred after exposure to high and low radiation doses are discussed. The physical and biological factors involved in the sequential development of radiation health effects and the different cellular responses to radiation injury are considered. The main criteria and features of radiation effects of high and low doses are comprehensively outlined

High energy multi-cycle terahertz generation

International Nuclear Information System (INIS)

Ahr, Frederike Beate

2017-10-01

Development of compact electron accelerators and free-electron lasers requires novel acceleration schemes at shorter driving wavelengths. The Axsis project seeks to develop terahertz based electron acceleration as well as the high energy terahertz sources required. This thesis explores the methods and optical material required for the generation of highenergy multi-cycle terahertz pulses. Two experimental concepts to generate high energy terahertz radiation are presented. In addition the theoretical background and the optical properties of pertinent optical materials in the terahertz range are discussed. Investigations of the materials are performed with a terahertz time domain spectrometer and a Fourier transform infrared spectrometer. The nonlinear optical crystal lithium niobate as well as other crystals suitable for the terahertz generation and in addition polymers and other radiation attenuators are characterized in the range from 0.2 to 1 THz. The theory describing the generation of narrowband terahertz radiation is evaluated. The experimental setups to generate terahertz radiation and to characterize its properties are described. The specific crystals - periodically poled lithium niobate (PPLN) - used in the experiments to generate the multi-cycle terahertz radiation are examined to determine e.g. the poling period. The first experimental concept splits the ultra fast, broadband pump pulses into a pulse train in order to pump the PPLN at a higher fluence while increasing the damage limit. The measurements confirm that a pulse train of ultra short, broadband pump pulses increases not only the terahertz energy but also the energy conversion efficiency. The second experimental concept utilizes chirped and delayed infrared laser pulses. This pulse format makes it possible to pump the crystal with high energy pulses resulting in high energy terahertz radiation. The concept is optimized to reach energies up to 127 μJ exceeding the existing results of narrowband

High energy multi-cycle terahertz generation

Energy Technology Data Exchange (ETDEWEB)

Ahr, Frederike Beate

2017-10-15

Development of compact electron accelerators and free-electron lasers requires novel acceleration schemes at shorter driving wavelengths. The Axsis project seeks to develop terahertz based electron acceleration as well as the high energy terahertz sources required. This thesis explores the methods and optical material required for the generation of highenergy multi-cycle terahertz pulses. Two experimental concepts to generate high energy terahertz radiation are presented. In addition the theoretical background and the optical properties of pertinent optical materials in the terahertz range are discussed. Investigations of the materials are performed with a terahertz time domain spectrometer and a Fourier transform infrared spectrometer. The nonlinear optical crystal lithium niobate as well as other crystals suitable for the terahertz generation and in addition polymers and other radiation attenuators are characterized in the range from 0.2 to 1 THz. The theory describing the generation of narrowband terahertz radiation is evaluated. The experimental setups to generate terahertz radiation and to characterize its properties are described. The specific crystals - periodically poled lithium niobate (PPLN) - used in the experiments to generate the multi-cycle terahertz radiation are examined to determine e.g. the poling period. The first experimental concept splits the ultra fast, broadband pump pulses into a pulse train in order to pump the PPLN at a higher fluence while increasing the damage limit. The measurements confirm that a pulse train of ultra short, broadband pump pulses increases not only the terahertz energy but also the energy conversion efficiency. The second experimental concept utilizes chirped and delayed infrared laser pulses. This pulse format makes it possible to pump the crystal with high energy pulses resulting in high energy terahertz radiation. The concept is optimized to reach energies up to 127 μJ exceeding the existing results of narrowband

The response of different types of TL lithium fluoride detectors to high-energy mixed radiation fields

Energy Technology Data Exchange (ETDEWEB)

Obryk, B. [Institute of Nuclear Physics PAN (IFJ), ul. Radzikowskiego 152, 31-342 Krakow (Poland)], E-mail: barbara.obryk@ifj.edu.pl; Bilski, P.; Budzanowski, M. [Institute of Nuclear Physics PAN (IFJ), ul. Radzikowskiego 152, 31-342 Krakow (Poland); Fuerstner, M. [CERN - European Organization for Nuclear Research, 1211 Geneva 23 (Switzerland); Ilgner, C. [CERN - European Organization for Nuclear Research, 1211 Geneva 23 (Switzerland) and University of Dortmund, Dortmund (Germany); Jaquenod, F. [Ecole d' Ingenieurs de Geneve, Geneva (Switzerland); Olko, P.; Puchalska, M. [Institute of Nuclear Physics PAN (IFJ), ul. Radzikowskiego 152, 31-342 Krakow (Poland); Vincke, H. [CERN - European Organization for Nuclear Research, 1211 Geneva 23 (Switzerland)

2008-02-15

Thermoluminescent (TL) dosimeters are routinely used to monitor absorbed doses in many kinds of radiation fields which contain photons, electrons and neutrons. However, TLDs are mainly calibrated to photon sources. We studied the response of TLDs to complex secondary fields arising during the operation of high-energy accelerators (e.g. the Large Hadron Collider (LHC) at CERN). The experiments were conducted at the CERN-EU high-energy reference field facility (CERF). Six different LiF-based TLDs (MTS-N, MTS-7, MTS-6, MCP-N, MCP-7, MCP-6) were exposed to various secondary CERF's fields (both for high and low doses), by placing them at various positions: at the target and concrete top and side positions. For the experiment at the target the corresponding Monte Carlo calculations were also carried out using the FLUKA transport code and compared with experimental results. In addition, alanine dosimeters were used as an independent reference. The results show that TLDs are well suited for monitoring radiation fields around the LHC. Nevertheless, further investigations are required, some of which are in progress.

International workshop on the 'Physics of interfaces by synchrotron radiation and other high energy probes'

International Nuclear Information System (INIS)

Krummacher, S.; Gudat, W.

1986-05-01

The present 'book of abstracts' consists of the abstracts of 23 lectures, held at the international workshop on the 'Physics of interfaces by synchrotron radiation and other high energy probes', April 1986, Bad Honnef, FRG. The subjects are: The use of photoemission in the study of interfaces and adsorbates, EEL spectroscopy applications, spin polarization, photoionization processes and EXAFS. (BHO)

Comparative effects of exposure to high-energy electrons and gamma radiation on active avoidance behaviour

International Nuclear Information System (INIS)

Hunt, W.A.

1983-01-01

The effect of two types of ionizing radiation was examined on active avoidance behaviour. Male Sprague-Dawley rats were trained to avoid footshock by jumping onto a retractable ledge. When irradiated with high-energy electrons or gamma photons, their performance was degraded in a dose-dependent manner. However, electrons were 1.6 times as effective as gamma photons with ED50s of 62 and 102 Gy, respectively. All animals recovered within 24 min for all doses used. The data suggest that different types of ionizing radiation may not be equivalent when assessing their effect on behaviour. (author)

Evaluation of fluence to dose equivalent conversion factors for high energy radiations, (1)

International Nuclear Information System (INIS)

Sato, Osamu; Uehara, Takashi; Yoshizawa, Nobuaki; Iwai, Satoshi; Tanaka, Shun-ichi.

1992-09-01

Computer code system and basic data have been investigated for evaluating fluence to dose equivalent conversion factors for photons and neutrons up to 10 GeV. The present work suggested that the conversion factors would be obtained by incorporating effective quality factors of charged particles into the HERMES (High Energy Radiation Monte Carlo Elaborate System) code system. The effective quality factors for charged particles were calculated on the basis of the Q-L relationships specified in the ICRP Publication-60. (author)

From nGy to MGy - new TL dosimetry of complex radiation at high-energy accelerators and thermonuclear fusion facilities

International Nuclear Information System (INIS)

Obryk, B.; Bilski, P.; Budzanowski, M.; Olko, P.

2011-01-01

One of the well known advantages of thermoluminescence (TL) detectors made of lithium fluoride doped with magnesium, copper and phosphorus (LiF:Mg,Cu,P) is their very high sensitivity to ionizing radiation. LiF:Mg,Cu,P detectors enable measurements of radiation doses from tens of nano grays up to a few kilo grays, when the total saturation of the signal of the so-called main dosimetric peak (at about 220 C. degrees) occurs. In 2006 for the first time we observed unprecedented high-temperature emission of LiF detectors heated to temperatures up to 600 C. degrees, after exposures to radiation doses ranging from 1 kGy to 1 MGy. For quantification of the glow curve shape changes of LiF:Mg,Cu,P detectors in this range of doses and determination of the absorbed dose, the high temperature coefficient (UHTR) was defined. This newly established dosimetric method was tested in a range of radiation qualities, such as gamma radiation, electron and proton beams, thermal neutron fields and in high-energy mixed fields around the SPS and PS accelerators at CERN. A number of dosimetric sets with LiF:Mg,Cu,P detectors are currently installed around the LHC at CERN. The new method for ultra-high dose range monitoring with a single LiF:Mg,Cu,P detector, which is capable of covering at least twelve orders of magnitude of doses, can be used for dosimetry at high energy accelerators and has great potential for accident dosimetry in particular. (authors)

High Confinement and High Density with Stationary Plasma Energy and Strong Edge Radiation Cooling in Textor-94

Science.gov (United States)

Messiaen, A. M.

1996-11-01

A new discharge regime has been observed on the pumped limiter tokamak TEXTOR-94 in the presence of strong radiation cooling and for different scenarii of additional hearing. The radiated power fraction (up to 90%) is feedback controlled by the amount of Ne seeded in the edge. This regime meets many of the necessary conditions for a future fusion reactor. Energy confinement increases with increasing densities (reminiscent of the Z-mode obtained at ISX-B) and as good as ELM-free H-mode confinement (enhancement factor verus ITERH93-P up to 1.2) is obtained at high densities (up to 1.2 times the Greenwald limit) with peaked density profiles showing a peaking factor of about 2 and central density values around 10^14cm-3. In experiments where the energy content of the discharges is kept constant with an energy feedback loop acting on the amount of ICRH power, stable and stationary discharges are obtained for intervals of more than 5s, i.e. 100 times the energy confinement time or about equal to the skin resistive time, even with the cylindrical q_α as low as 2.8 β-values up to the β-limits of TEXTOR-94 are achieved (i.e. β n ≈ 2 of and β p ≈ 1.5) and the figure of merit for ignition margin f_Hqa in these discharges can be as high as 0.7. No detrimental effects of the seeded impurity on the reactivity of the plasma are observed. He removal in these discharges has also been investigated. [1] Laboratoire de Physique des Plasmas-Laboratorium voor Plasmafysica, Association "EURATOM-Belgian State", Ecole Royale Militaire-Koninklijke Militaire School, Brussels, Belgium [2] Institut für Plasmaphysik, Forschungszentrum Jülich, GmbH, Association "EURATOM-KFA", Jülich, Germany [3] Fusion Energy Research Program, Mechanical Engineering Division, University of California at San Diego, La Jolla, USA [4] FOM Institüt voor Plasmafysica Rijnhuizen, Associatie "FOM-EURATOM", Nieuwegein, The Netherlands [*] Researcher at NFSR, Belgium itemize

Search for emission of ultra high energy radiation from active galactic nuclei

International Nuclear Information System (INIS)

1993-01-01

A search for emission of ultra-high energy gamma radiation from 13 active galactic nuclei that were detected by EGRET, using the CYGNUS extensive air-shower array, is described. The data set has been searched for continuous emission, emission on the time scale of one week, and for on the time scale of out day. No evidence for emission from any of the AGN on any of the time scales examined was found. The 90% C.L. upper limit to the continuous flux from Mrk 421 above 50 TeV is 7.5 x 10 -14 cm -2 s -1

Enhancing radiative energy transfer through thermal extraction

Science.gov (United States)

Tan, Yixuan; Liu, Baoan; Shen, Sheng; Yu, Zongfu

2016-06-01

Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a). In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics. Thermal extraction works by using a specially designed thermal extractor to convert and guide the near-field energy to the far field, as shown in Fig. 1b. The same blackbody as shown in Fig. 1a is placed closely below the thermal extractor with a spacing smaller than the thermal wavelength. The near-field coupling transfers radiative energy with a density greater than σT4. The thermal extractor, made from transparent and high-index or structured materials, does not emit or absorb any radiation. It transforms the near-field energy and sends it toward the far field. As a result, the total amount of far-field radiative heat dissipated by the same blackbody is greatly enhanced above SσT4, where S is the area of the emitter. This paper will review the progress in thermal

High energy x-ray synchrotron radiation analysis of residual stress distribution of shot-peened steels

International Nuclear Information System (INIS)

Tanaka, Keisuke; Akiniwa, Yoshiaki; Kimachi, Hirohisa; Suzuki, Kenji; Yanase, Etsuya; Nishio, Kouji; Kusumi, Yukihiro

2001-01-01

A high energy X-ray beam from synchrotron radiation source SPring-8 was used to determine the residual stress distribution beneath the shot-peened surface of carbon steel plates. By using the monochromatic X-ray beam with an energy of 72 keV, the relation between 2θ and sin 2 ψ was obtained by the side-inclination method upto sin 2 ψ = 0.9. The distribution of the residual stress was determined from the non-linearity of the relation between 2θ and sin 2 ψ. (author)

The RaDIATE High-Energy Proton Materials Irradiation Experiment at the Brookhaven Linac Isotope Producer Facility

Energy Technology Data Exchange (ETDEWEB)

Ammigan, Kavin; et al.

2017-05-01

The RaDIATE collaboration (Radiation Damage In Accelerator Target Environments) was founded in 2012 to bring together the high-energy accelerator target and nuclear materials communities to address the challenging issue of radiation damage effects in beam-intercepting materials. Success of current and future high intensity accelerator target facilities requires a fundamental understanding of these effects including measurement of materials property data. Toward this goal, the RaDIATE collaboration organized and carried out a materials irradiation run at the Brookhaven Linac Isotope Producer facility (BLIP). The experiment utilized a 181 MeV proton beam to irradiate several capsules, each containing many candidate material samples for various accelerator components. Materials included various grades/alloys of beryllium, graphite, silicon, iridium, titanium, TZM, CuCrZr, and aluminum. Attainable peak damage from an 8-week irradiation run ranges from 0.03 DPA (Be) to 7 DPA (Ir). Helium production is expected to range from 5 appm/DPA (Ir) to 3,000 appm/DPA (Be). The motivation, experimental parameters, as well as the post-irradiation examination plans of this experiment are described.

The effects of high energy radiation on the pulping properties of Pinus radiation and Eucalyptus regnans

International Nuclear Information System (INIS)

McLaren, K.G.; Garland, C.P.; Higgins, H.G.

1976-01-01

Studies have been made of the effects of high energy radiation on the pulping behaviour of Eucalyptus regnans and Pinus radiata. Pre-irradiation of wood chips with small doses of 60 Co gamma radiation (up to about 0.2 Mrad) caused little degradation of the cellulose, and had only minor effects on the kraft pulping properties of both wood species. Pulp yield, Kappa number and strength properties of the pulps showed little change. There was also little effect on the bisulphite cooking of Pinus radiata. As the dose was increased to 1 Mrad, degradation of cellulose (as indicated by degree of polymerisation measurements) became significant, and Kraft pulp yields from both woods showed small reductions. The Kappa number and physical properties of these pulps were little affected at this dose level. A gamma radiation dose of 10 Mrad produced marked depolymerisation of the cellulose, and big reductions in kraft and neutral sulphite semi-chemical pulp yields. The kraft pulps showed a much higher lignin content. Some low dose (0.15 Mrad) irradiations on thin chips were carried out with a 1 MeV electron accelerator. In contrast to comparable gamma irradiations, this treatment produced discernible changes in kraft pulping behaviour. The pulp yield, under the same cooking conditions, appears to be slightly higher, but the Lignin content of the pulp was increased. (Author)

High-energy X-ray detection using organic luminescent materials: a novel application for radiation therapy

International Nuclear Information System (INIS)

Schimitberger, Thiago; Ferreira, Giovana Ribeiro; Silva, Mariana de Melo; Saraiva, M.F.; Bianchi, Rodrigo Fernando

2010-01-01

In this work, it is presented the characterization and fabrication of a novel ionizing radiation sensor for high energy X-ray (6 MeV). It is used organic luminescent materials usually applied in light-emitting and nanostructure device, but still few explored in radiation dosimetry. Organic solutions of tris(8-hydroxyquinolinato) aluminum - Alq_3 and poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] - MEH-PPV were prepared to better study the impact of spectral overlap between the Alq_3 emission and MEH-PPV absorption. It is observed a blue-shift on the photoluminescence of the MEH-PPV/Alq_3 solution system from red-orange (λ_m_a_x = 598 nm) to green (λ_m_a_x = 545 nm) when the radiation dose changes from 0 to 100 Gy. This effect is attributed to the photooxidation process of MEH-PPV and was employed to design dose accumulation sensors in order to represent easily the radiation dose for cancer treatment. (author)

Limiting energy loss distributions for multiphoton channeling radiation

International Nuclear Information System (INIS)

Bondarenco, M.V.

2015-01-01

Recent results in the theory of multiphoton spectra for coherent radiation sources are overviewed, with the emphasis on channeling radiation. For the latter case, the importance of the order of resummation and averaging is emphasized. Limiting shapes of multiphoton spectra at high intensity are discussed for different channeling regimes. In some spectral regions, there emerges a correspondence between the radiative energy loss and the electron integrals of motion

Laboratory astrophysics with high energy and high power lasers: from radiative shocks to young star jets

International Nuclear Information System (INIS)

Diziere, A.

2012-01-01

Laboratory astrophysics are a rapidly developing domain of the High Energy Density Physics. It aims to recreate at smaller scales physical processes that astronomical telescopes have difficulties observing. We shall approach, in this thesis, three major subjects: 1) Jets ejected from young stars, characterized by an important collimation degree and ending with a bow shock; 2) Radiative shocks in which radiation emitted by the shock front itself plays a dominant role in its structure and 3) Accretion shocks in magnetic cataclysmic variables whose important cooling factor allows them to reach stationarity. From the conception to experimental realization, we shall attempt to reproduce in laboratory each of these processes by respecting the scaling laws linking both situations (experimental and astrophysical) established beforehand. The implementation of a large array of visible and X-ray diagnostics will finally allow to completely characterize them and calculate the dimensionless numbers that validate the astrophysical relevance. (author) [fr

Radiation collimator for use with high energy radiation beams

International Nuclear Information System (INIS)

Malak, S.P.

1978-01-01

A collimator is described for use with a beam of radiation, and in particular, for use in controlling the cross-sectional size and shape of the radiation beam and intercepting undesired off-focus radiation in an x-ray apparatus. The collimator is positioned adjacent to the source of radiation and embodies a plurality longitudinally extending leaves pivotally mounted on and between two supports, the leaves move about their pivots to close overlapping relation to define a hollow cone. The cone defines an aperture at its narrow end which can be adjusted in size and shape by rotation of the two supports which are adaptable to being moved one relative to the other, to cause an expansion or contraction of the hollow cone and correspondingly an increase or decrease of the cross-sectional size and/or shape of the radiation beam passing through the aperture

Effect of High Energy Radiation on Mechanical Properties of Graphite Fiber Reinforced Composites. M.S. Thesis

Science.gov (United States)

Naranong, N.

1980-01-01

The flexural strength and average modulus of graphite fiber reinforced composites were tested before and after exposure to 0.5 Mev electron radiation and 1.33 Mev gamma radiation by using a three point bending test (ASTM D-790). The irradiation was conducted on vacuum treated samples. Graphite fiber/epoxy (T300/5208), graphite fiber/polyimide (C6000/PMR 15) and graphite fiber/polysulfone (C6000/P1700) composites after being irradiated with 0.5 Mev electron radiation in vacuum up to 5000 Mrad, show increases in stress and modulus of approximately 12% compared with the controls. Graphite fiber/epoxy (T300/5208 and AS/3501-6), after being irradiated with 1.33 Mev gamma radiation up to 360 Mrads, show increases in stress and modulus of approximately 6% at 167 Mrad compared with the controls. Results suggest that the graphite fiber composites studied should withstand the high energy radiation in a space environment for a considerable time, e.g., over 30 years.

Intercomparison of radiation protection devices in a high-energy stray neutron field. Part III: Instrument response

CERN Document Server

Silari, M; Beck, P; Bedogni, R; Cale, E; Caresana, M; Domingo, C; Donadille, L; Dubourg, N; Esposito, A; Fehrenbacher, G; Fernández, F; Ferrarini, M; Fiechtner, A; Fuchs, A; García, M J; Golnik, N; Gutermuth, F; Khurana, S; Klages, Th; Latocha, M; Mares, V; Mayer, S; Radon, T; Reithmeier, H; Rollet, S; Roos, H; Rühm, W; Sandri, S; Schardt, D; Simmer, G; Spurný, F; Trompier, F; Villa-Grasa, C; Weitzenegger, E; Wiegel, B; Wielunski, M; Wissmann, F; Zechner, A; Zielczyński, M

2009-01-01

The European Commission has funded within its 6th Framework Programme a three-year project (2005–2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organizational framework for this project was provided by the European radiation Dosimetry Group EURADOS. Work Package 6 of CONRAD dealt with “complex mixed radiation fields at workplaces” and in this context it organised a benchmark exercise, which included both measurements and calculations, in a stray radiation field at a high-energy particle accelerator at GSI, Germany. The aim was to intercompare the response of several types of active detectors and passive dosemeters in a well-characterised workplace field. The Monte Carlo simulations of the radiation field and the experimental determination of the neutron spectra with various Bonner Sphere Spectrometers are discussed in Rollet et al. (2008) and in Wiegel et al. (2008). This paper focuses on the intercomparison of the response of the dosemeters in terms of ambient dose equivalent. Th...

Baryon scattering at high energies. Wave function, impact factor, and gluon radiation

International Nuclear Information System (INIS)

Bartels, J.; Motyka, L.; Jagellonian Univ., Krakow

2007-11-01

The scattering of a baryon consisting of three massive quarks is investigated in the high energy limit of perturbative QCD. A model of a relativistic proton-like wave function, dependent on valence quark longitudinal and transverse momenta and on quark helicities, is proposed, and we derive the baryon impact factors for two, three and four t-channel gluons. We find that the baryonic impact factor can be written as a sum of three pieces: in the first one a subsystem consisting of two of the three quarks behaves very much like the quark-antiquark pair in γ * scattering, whereas the third quark acts as a spectator. The second term belongs to the odderon, whereas in the third (C-even) piece all three quarks participate in the scattering. This term is new and has no analogue in γ * scattering. We also study the small x evolution of gluon radiation for each of these three terms. The first term follows the same pattern of gluon radiation as the γ * -initiated quark-antiquark dipole, and, in particular, it contains the BFKL evolution followed by the 2→4 transition vertex (triple Pomeron vertex). The odderon-term is described by the standard BKP evolution, and the baryon couples to both known odderon solutions, the Janik-Wosiek solution and the BLV solution. Finally, the t-channel evolution of the third term starts with a three reggeized gluon state which then, via a new 3→4 transition vertex, couples to the four gluon (two-Pomeron) state. We briefly discuss a few consequences of these findings, in particular the pattern of unitarization of high energy baryon scattering amplitudes. (orig.)

Baryon scattering at high energies. Wave function, impact factor, and gluon radiation

Energy Technology Data Exchange (ETDEWEB)

Bartels, J. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Motyka, L. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik]|[Jagellonian Univ., Krakow (Poland). Inst. of Physics

2007-11-15

The scattering of a baryon consisting of three massive quarks is investigated in the high energy limit of perturbative QCD. A model of a relativistic proton-like wave function, dependent on valence quark longitudinal and transverse momenta and on quark helicities, is proposed, and we derive the baryon impact factors for two, three and four t-channel gluons. We find that the baryonic impact factor can be written as a sum of three pieces: in the first one a subsystem consisting of two of the three quarks behaves very much like the quark-antiquark pair in {gamma}{sup *} scattering, whereas the third quark acts as a spectator. The second term belongs to the odderon, whereas in the third (C-even) piece all three quarks participate in the scattering. This term is new and has no analogue in {gamma}{sup *} scattering. We also study the small x evolution of gluon radiation for each of these three terms. The first term follows the same pattern of gluon radiation as the {gamma}{sup *}-initiated quark-antiquark dipole, and, in particular, it contains the BFKL evolution followed by the 2{yields}4 transition vertex (triple Pomeron vertex). The odderon-term is described by the standard BKP evolution, and the baryon couples to both known odderon solutions, the Janik-Wosiek solution and the BLV solution. Finally, the t-channel evolution of the third term starts with a three reggeized gluon state which then, via a new 3{yields}4 transition vertex, couples to the four gluon (two-Pomeron) state. We briefly discuss a few consequences of these findings, in particular the pattern of unitarization of high energy baryon scattering amplitudes. (orig.)

A radiation transfer model for the Milky Way: I. Radiation fields and application to high-energy astrophysics★

Science.gov (United States)

Popescu, C. C.; Yang, R.; Tuffs, R. J.; Natale, G.; Rushton, M.; Aharonian, F.

2017-09-01

We present a solution for the ultraviolet - submillimetre (submm) interstellar radiation fields (ISRFs) of the Milky Way (MW), derived from modelling COBE, IRAS and Planck maps of the all-sky emission in the near-, mid-, far-infrared and submm. The analysis uses the axisymmetric radiative transfer model that we have previously implemented to model the panchromatic spectral energy distributions (SEDs) of star-forming galaxies in the nearby universe, but with a new methodology allowing for optimization of the radial and vertical geometry of stellar emissivity and dust opacity, as deduced from the highly resolved emission seen from the vantage point of the Sun. As such, this is the first self-consistent model of the broad-band continuum emission from the MW. In this paper, we present model predictions for the spatially integrated SED of the MW as seen from the Sun, showing good agreement with the data, and give a detailed description of the solutions for the distribution of ISRFs, as well as their physical origin, throughout the volume of the galaxy. We explore how the spatial and spectral distributions of our new predictions for the ISRF in the MW affects the amplitude and spectral distributions of the gamma rays produced via inverse Compton scattering for cosmic ray (CR) electrons situated at different positions in the galaxy, as well as the attenuation of the gamma rays due to interactions of the gamma-ray photons with photons of the ISRF. We also compare and contrast our solutions for the ISRF with those incorporated in the galprop package used for modelling the high-energy emission from CR in the MW.

Ionizing radiation, nuclear energy and radiation protection for school

International Nuclear Information System (INIS)

Lucena, E.A.; Reis, R.G.; Pinho, A.S.; Alves, A.S.; Rio, M.A.P.; Reis, A.A.; Silva, J.W.S.; Paula, G.A. de; Goncalves Junior, M.A.

2017-01-01

Since the discovery of X-rays in 1895, ionizing radiation has been applied in many sectors of society, such as medicine, industry, safety, construction, engineering and research. However, population is unaware of both the applications of ionizing radiation and their risks and benefits. It can be seen that most people associate the terms 'radiation' and 'nuclear energy' with the atomic bomb or cancer, most likely because of warlike applications and the stealthy way radioactivity had been treated in the past. Thus, it is necessary to clarify the population about the main aspects related to the applications, risks and associated benefits. These knowledge can be disseminated in schools. Brazilian legislation for basic education provides for topics such as nuclear energy and radioactivity to high school students. However, some factors hamper such an educational practice, namely, few hours of class, textbooks do not address the subject, previous concepts obtained in the media, difficulty in dealing with the subject in the classroom, phobia, etc. One solution would be the approximation between schools and institutions that employ technologies involving radioactivity, which would allow students to know the practices, associated radiological protection, as well as the risks and benefits to society. Currently, with the increasing application of ionizing radiation, especially in medicine, it is necessary to demystify the use of radioactivity. (author)

Response study of fission track detectors using two different moderator designs in a high-energy radiation field

Energy Technology Data Exchange (ETDEWEB)

Mayer, S. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)], E-mail: Sabine.Mayer@psi.ch; Boschung, M.; Fiechtner, A. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Fuerstner, M. [CERN, CH-1211 Geneva 23 (Switzerland); Wernli, C. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

2008-02-15

Fission track detectors in the center of moderating spheres are routinely used to measure the ambient dose equivalent due to neutrons in the environmental dosimetry at Paul Scherrer Institut (PSI). Originally, the system was designed to cope with neutrons from skyshine effects. Later, the system was also adapted behind the shielding of PSI's accelerators. Nowadays, as a consequence of continuously upgrading accelerator energies and intensities, the neutron energy behind thick shielding can range from fractions of eV to about 1 GeV (e.g. at CERN). For this reason a measurement campaign in a high-energy stray radiation field at CERN's High-Energy Reference Field Facility (CERF) was initiated to study and compare the response of the already existing detector-moderator configuration and a new design, the 'GSI ball'. Employing an additional lead layer in a moderator sphere of 32.5 cm diameter, the GSI ball was primarily designed for the use with thermoluminescent based dosimeters in its center in order to optimize the response for the measurement of H*(10) to higher neutron energies. In this work, the measurement results for fission track detectors using two different radiator materials in the PSI and the GSI moderator are presented. Based on these studies, on the one hand, field calibration factors for the use in presumably similar high-energy fields around accelerators could be deduced. On the other hand, it could be shown that there is no need to replace the established PSI moderator by the GSI moderator since the combination of fission track detector and GSI moderator does not result in a significant sensitivity improvement.

Response study of fission track detectors using two different moderator designs in a high-energy radiation field

International Nuclear Information System (INIS)

Mayer, S.; Boschung, M.; Fiechtner, A.; Fuerstner, M.; Wernli, C.

2008-01-01

Fission track detectors in the center of moderating spheres are routinely used to measure the ambient dose equivalent due to neutrons in the environmental dosimetry at Paul Scherrer Institut (PSI). Originally, the system was designed to cope with neutrons from skyshine effects. Later, the system was also adapted behind the shielding of PSI's accelerators. Nowadays, as a consequence of continuously upgrading accelerator energies and intensities, the neutron energy behind thick shielding can range from fractions of eV to about 1 GeV (e.g. at CERN). For this reason a measurement campaign in a high-energy stray radiation field at CERN's High-Energy Reference Field Facility (CERF) was initiated to study and compare the response of the already existing detector-moderator configuration and a new design, the 'GSI ball'. Employing an additional lead layer in a moderator sphere of 32.5 cm diameter, the GSI ball was primarily designed for the use with thermoluminescent based dosimeters in its center in order to optimize the response for the measurement of H*(10) to higher neutron energies. In this work, the measurement results for fission track detectors using two different radiator materials in the PSI and the GSI moderator are presented. Based on these studies, on the one hand, field calibration factors for the use in presumably similar high-energy fields around accelerators could be deduced. On the other hand, it could be shown that there is no need to replace the established PSI moderator by the GSI moderator since the combination of fission track detector and GSI moderator does not result in a significant sensitivity improvement

Shielding for high energy, high intensity electron accelerator installation

International Nuclear Information System (INIS)

Warawas, C.; Chongkum, S.

1997-03-01

The utilization of electron accelerators (eBA) is gradually increased in Thailand. For instance, a 30-40 MeV eBA are used for tumor and cancer therapy in the hospitals, and a high current eBA in for gemstone colonization. In the near future, an application of eBA in industries will be grown up in a few directions, e.g., flue gases treatment from the coal fire-power plants, plastic processing, rubber vulcanization and food preservation. It is the major roles of Office of Atomic Energy for Peace (OAEP) to promote the peaceful uses of nuclear energy and to regulate the public safety and protection of the environment. By taking into account of radiation safety aspect, high energy electrons are not only harmful to human bodies, but the radioactive nuclides can be occurred. This report presents a literature review by following the National Committee on Radiation Protection and Measurements (NCRP) report No.31. This reviews for parametric calculation and shielding design of the high energy (up to 100 MeV), high intensity electron accelerator installation

Measurement of energy transitions for the decay radiations of 75Ge and 69Ge in a high purity germanium detector

Science.gov (United States)

Aydın, Güral; Usta, Metin; Oktay, Adem

2018-06-01

Photoactivation experiments have a wide range of application areas in nuclear, particle physics, and medical physics such as measuring energy levels and half-lifes of nuclei, experiments for understanding imaging methods in medicine, isotope production for patient treatment, radiation security and transportation, radiation therapy, and astrophysics processes. In this study, some energy transition values of the decay radiations of 75Ge and 69Ge, which are the products of photonuclear reactions (γ, n) with germanium isotopes (75Ge and 69Ge), were measured. The gamma spectrum as a result of atomic transitions were analysed by using a high purity semiconductor germanium detector and the energy transition values which are presented here were compared with the ones which are the best in literature. It was observed that the results presented are in agreement with literature in error range and some results have better precisions.

DNA in glasses at 77 K: high energy ionizing radiation versus UV electron injection

International Nuclear Information System (INIS)

Malone, M.E.; Parker, A.W.

1994-01-01

Most in the field of ionizing radiation damage to DNA in frozen aqueous solutions agree that two major types of radical ions are formed, i.e. . G + / . A + and . T - / . C - . The main evidence stems from EPR and strand break studies. Fluid solutions exposed to laser light are known to give G .+ and e solv - with low yields of single strand breaks. We have explored this contrast by photoionizing DNA solutions at 77 K, in the expectation that this would prevent the formation of e solv - and hence that the results might be similar to those for high energy radiation. They are not: the results show only the formation of G .+ (or) A .+ , the fate of the ejected electrons is unclear except for sodium perchlorate glasses when they react to give O .- . (Author)

Electro-optical equivalent calibration technology for high-energy laser energy meters

Energy Technology Data Exchange (ETDEWEB)

Wei, Ji Feng, E-mail: wjfcom2000@163.com [State Key Laboratory of Precision Measurement Technology and Instrument, Tsinghua University, Beijing 100084 (China); Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China); Graduate School of China Academy of Engineering Physics, Beijing 100088 (China); Key Laboratory of Laser Science and Technology, China Academy of Engineering Physics, Mianyang 621900 (China); Chang, Yan; Zhang, Kai; Hu, Xiao Yang; Zhang, Wei [Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China); Key Laboratory of Laser Science and Technology, China Academy of Engineering Physics, Mianyang 621900 (China); Sun, Li Qun [State Key Laboratory of Precision Measurement Technology and Instrument, Tsinghua University, Beijing 100084 (China)

2016-04-15

Electro-optical equivalent calibration with high calibration power and high equivalence is particularly well-suited to the calibration of high-energy laser energy meters. A large amount of energy is reserved during this process, however, which continues to radiate after power-off. This study measured the radiation efficiency of a halogen tungsten lamp during power-on and after power-off in order to calculate the total energy irradiated by a lamp until the high-energy laser energy meter reaches thermal equilibrium. A calibration system was designed based on the measurement results, and the calibration equivalence of the system was analyzed in detail. Results show that measurement precision is significantly affected by the absorption factor of the absorption chamber and by heat loss in the energy meter. Calibration precision is successfully improved by enhancing the equivalent power and reducing power-on time. The electro-optical equivalent calibration system, measurement uncertainty of which was evaluated as 2.4% (k = 2), was used to calibrate a graphite-cone-absorption-cavity absolute energy meter, yielding a calibration coefficient of 1.009 and measurement uncertainty of 3.5% (k = 2). A water-absorption-type high-energy laser energy meter with measurement uncertainty of 4.8% (k = 2) was considered the reference standard, and compared to the energy meter calibrated in this study, yielded a correction factor of 0.995 (standard deviation of 1.4%).

Photographic film dosimetry for high-energy accelerator radiation

International Nuclear Information System (INIS)

Komochkov, M.M.; Salatskaya, M.I.

1981-01-01

A technique for personnel photographic film dosimetry (PPFDN) of wide energy spectrum neutrons intended for measuring the effect of accelerating device radiation on personnel is described. Procedures of data measurement and processing as well as corrections to hadron contribution are presented. It is noted that the PPFDN method permits to measure a neutron dose equivalent for personnel in the range from 0.01 to 0.02 up to 100 rem, if the relativistic neutron contribution to a total dose does not exceed 5%. The upper limit of the measured dose reduced several times for a greater contribution of relativistic neutrons to the total dose [ru

Radiation from silver films bombarded by low-energy electrons

International Nuclear Information System (INIS)

Chung, M.S.; Callcott, T.A.; Kretschmann, E.; Arakawa, E.T.

1980-01-01

Emission spectra from Ag films irradiated by low energy electrons (20-1500 eV) have been measured, and the results compared with theory. For relatively smooth films, two peaks in the spectra are resolved. One at 3.73 eV, the volume plasmon energy, is attributed to transition radiation and/or bremsstrahlung. The second, at about 3.60 eV, is very sensitive to surface roughness in both position and magnitude and is produced by roughness-coupled radiation from surface plasmons. For rough films, the roughness-coupled radiation dominates the emission. In addition to spectral shapes, the polarization of the radiation and its intensity as a function of electron energy were measured. The experimental results are compared with new calculations of roughness-coupled emission which account for most of our observations. They indicate that high wavevector roughness components play the dominant role in the emission process. (orig.)

Hawking radiation of a high-dimensional rotating black hole

Energy Technology Data Exchange (ETDEWEB)

Zhao, Ren; Zhang, Lichun; Li, Huaifan; Wu, Yueqin [Shanxi Datong University, Institute of Theoretical Physics, Department of Physics, Datong (China)

2010-01-15

We extend the classical Damour-Ruffini method and discuss Hawking radiation spectrum of high-dimensional rotating black hole using Tortoise coordinate transformation defined by taking the reaction of the radiation to the spacetime into consideration. Under the condition that the energy and angular momentum are conservative, taking self-gravitation action into account, we derive Hawking radiation spectrums which satisfy unitary principle in quantum mechanics. It is shown that the process that the black hole radiates particles with energy {omega} is a continuous tunneling process. We provide a theoretical basis for further studying the physical mechanism of black-hole radiation. (orig.)

Radiation processing of liquid with low energy electron accelerator

International Nuclear Information System (INIS)

Makuuchi, Keizo

2003-01-01

Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by γ-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with γ-ray should be carried out. (author)

Radiation processing of liquid with low energy electron accelerator

Energy Technology Data Exchange (ETDEWEB)

Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2003-02-01

Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

A new era in nuclear energy science. When will radiation application receive citizenship ranking along with energy utilization

International Nuclear Information System (INIS)

Tabata, Yoneho; Tagawa, Seiichi; Saito, Naoki; Fujii, Yasuhiko

2005-01-01

Japan has been obtaining definite results in these decades in both fields of nuclear power generation (energy utilization) and radiation application thus contributing to a sustainable development of the world. The present special issue of 'Atom Eye' introduces (1) Japanese achievements in cooperative relationships with developing countries in the field of radiation applications, (2) history of research and development of radiation-utilization techniques in Japan, (3) present status of quantum-beam applications in life-science, medial application, and nano-technology, etc, (4) applications of high-intensity neutron source, (5) cancer therapy using high-energy heavy-ion beams, (6) radiation sterilizations, (7) radiation mutations, (8) three interviewer's reports visiting several research institutes of radiation applications in Japan, and introduction of (9) a bencher enterprise and also (10) an accelerator business. (S. Ohno)

Shielding Design and Leaking Measurement for the High Energy Radiation Room

International Nuclear Information System (INIS)

Chu, Sung Sil

1979-01-01

An optimum shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV , are presented. We obtained following results by comparison between the p recalculating values and actual survey after complete installation of radio generating units. 1. The precalculating values of protective barrier are 5 times more protective than that of actual measurement. 2. The dose rate during exposure are 2-10 mR /hr at out of the door and the control room. 3. The exposure doses for occupationally persons are relatively low levels, the average values of exposure dose is 10-50 mR per month. 4. The foul smelling and ozone gas production from long exposure of cancer patients cannot be eliminated when the room is ill ventilated

Cadmium telluride gamma-radiation detectors with a high energy resolution

International Nuclear Information System (INIS)

Alekseeva, L.A.; Dorogov, P.G.; Ivanov, V.I.; Khusainov, A.K.

1985-01-01

This paper considers the possibility of improving the energy resolution of cadmium telluride gamma-radiation detectors through the choice of the geometry and size of the sensitive region of the detector. The optimum ratio of the product of the mobility and lifetime for electrons to the same product for holes from the point of view of energy resolution is greater than or equal to 10 2 for a detector of spherical geometry and should be less than or equal to 10 for a cylindrical geometry and approximately 1 for a planar geometry. The optimum values of the major and minor radii of a spherical detector are calculated

High-throughput identification of ionizing radiation-sensitive plant genes and development of radiation indicator plant and radiation sensing Genechip

International Nuclear Information System (INIS)

Kim, Dong Sub; Kim, Jinbaek; Ha, Bokeun; Kim, Sang Hoon; Kim, Sunhee

2013-05-01

Physiological analysis of monocot model plant (rice) in response to ionizing radiation (cosmic-ray, gamma-ray, Ion beam). - Identification of antioxidant characters through cytochemical analysis. - Comparison of antioxidant activities in response to ionizing irradiation. - Evaluation of anthocyanin quantity in response to ionizing irradiation. Ionization energy response gene family analysis via bioinformatic validation. - Expression analysis of monocot and dicot gene families. - In silico and bioinformatic approach to elucidate gene function. Characterization and functional analysis of genes specifically expressed in response to ionizing irradiation (cosmic-ray, gamma-ray, Ion beam). - High throughput trancriptomic analysis of plants under ionizing radiation using microarray. - Promotor and cis-element analysis of genes specifically expressed in response to ionizing radiation. - Validation and function analysis of candidate genes. - Elucidation of plant mechanism of sensing and response to ionization energy. Development of bioindicator plants detecting ionization energy. - Cloning and identification of 'Radio marker genes (RMG)'. - Development of Over-expression (O/E) or Knock-out (K/O) plant using RMG. Development of Genechip as an ionization energy detector. - Expression profiling analysis of genes specifically expression in response to ionization energy. - Prepare high-conserved gene specific oligomer. - Development of ionization energy monitoring Genechip and application

High-throughput identification of ionizing radiation-sensitive plant genes and development of radiation indicator plant and radiation sensing Genechip

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Sub; Kim, Jinbaek; Ha, Bokeun; Kim, Sang Hoon; Kim, Sunhee

2013-05-15

Physiological analysis of monocot model plant (rice) in response to ionizing radiation (cosmic-ray, gamma-ray, Ion beam). - Identification of antioxidant characters through cytochemical analysis. - Comparison of antioxidant activities in response to ionizing irradiation. - Evaluation of anthocyanin quantity in response to ionizing irradiation. Ionization energy response gene family analysis via bioinformatic validation. - Expression analysis of monocot and dicot gene families. - In silico and bioinformatic approach to elucidate gene function. Characterization and functional analysis of genes specifically expressed in response to ionizing irradiation (cosmic-ray, gamma-ray, Ion beam). - High throughput trancriptomic analysis of plants under ionizing radiation using microarray. - Promotor and cis-element analysis of genes specifically expressed in response to ionizing radiation. - Validation and function analysis of candidate genes. - Elucidation of plant mechanism of sensing and response to ionization energy. Development of bioindicator plants detecting ionization energy. - Cloning and identification of 'Radio marker genes (RMG)'. - Development of Over-expression (O/E) or Knock-out (K/O) plant using RMG. Development of Genechip as an ionization energy detector. - Expression profiling analysis of genes specifically expression in response to ionization energy. - Prepare high-conserved gene specific oligomer. - Development of ionization energy monitoring Genechip and application.

Darwin: Dose monitoring system applicable to various radiations with wide energy ranges

International Nuclear Information System (INIS)

Sato, T.; Satoh, D.; Endo, A.; Yamaguchi, Y.

2007-01-01

A new radiation dose monitor, designated as DARWIN (Dose monitoring system Applicable to various Radiations with Wide energy ranges), has been developed for real-time monitoring of doses in workspaces and surrounding environments of high-energy accelerator facilities. DARWIN is composed of a Phoswitch-type scintillation detector, which consists of liquid organic scintillator BC501A coupled with ZnS(Ag) scintillation sheets doped with 6 Li, and a data acquisition system based on a Digital-Storage-Oscilloscope. DARWIN has the following features: (1) capable of monitoring doses from neutrons, photons and muons with energies from thermal energy to 1 GeV, 150 keV to 100 MeV and 1 MeV to 100 GeV, respectively, (2) highly sensitive with precision and (3) easy to operate with a simple graphical user-interface. The performance of DARWIN was examined experimentally in several radiation fields. The results of the experiments indicated the accuracy and wide response range of DARWIN for measuring dose rates from neutrons, photons and muons with wide energies. It was also found from the experiments that DARWIN enables us to monitor small fluctuations of neutron dose rates near the background level because of its high sensitivity. With these properties, DARWIN will be able to play a very important role for improving radiation safety in high-energy accelerator facilities. (authors)

A Green Energy Application in Energy Management Systems by an Artificial Intelligence-Based Solar Radiation Forecasting Model

Directory of Open Access Journals (Sweden)

Ping-Huan Kuo

2018-04-01

Full Text Available The photovoltaic (PV systems generate green energy from the sunlight without any pollution or noise. The PV systems are simple, convenient to install, and seldom malfunction. Unfortunately, the energy generated by PV systems depends on climatic conditions, location, and system design. The solar radiation forecasting is important to the smooth operation of PV systems. However, solar radiation detected by a pyranometer sensor is strongly nonlinear and highly unstable. The PV energy generation makes a considerable contribution to the smart grids via a large number of relatively small PV systems. In this paper, a high-precision deep convolutional neural network model (SolarNet is proposed to facilitate the solar radiation forecasting. The proposed model is verified by experiments. The experimental results demonstrate that SolarNet outperforms other benchmark models in forecasting accuracy as well as in predicting complex time series with a high degree of volatility and irregularity.

Energy balance in processes of transition radiation

International Nuclear Information System (INIS)

Vladimirov, S.V.; Tsytovich, V.N.

1985-01-01

The authors consider the transition radiation arising when a charged particle crosses an interface between two nonabsorbing media. It is shown that energy balance is observed under these circumstances. The fulfillment of energy balance in transition radiation for nonabsorbing media is rigorously demonstrated. This allows one to find the energy of the transition radiation from the change in the energy of the intrinsic field of the charge and the work of forces for volume waves, which in a number of cases of complicated configurations may prove to be considerably simpler than a direct calculation of the radiation power. For surface waves, a calculation of the work of forces enables one to determine the radiation power directly

HIGH-ENERGY EMISSION OF GRB 130427A: EVIDENCE FOR INVERSE COMPTON RADIATION

International Nuclear Information System (INIS)

Fan, Yi-Zhong; Zhang, Fu-Wen; He, Hao-Ning; Zhou, Bei; Yang, Rui-Zhi; Jin, Zhi-Ping; Wei, Da-Ming; Tam, P. H. T.; Liang, Yun-Feng

2013-01-01

A nearby superluminous burst GRB 130427A was simultaneously detected by six γ-ray space telescopes (Swift, the Fermi GLAST Burst Monitor (GBM)/Large Area Telescope, Konus-Wind, SPI-ACS/INTEGRAL, AGILE, and RHESSI) and by three RAPTOR full-sky persistent monitors. The isotropic γ-ray energy release is ∼10 54 erg, rendering it the most powerful explosion among gamma-ray bursts (GRBs) with a redshift z ≤ 0.5. The emission above 100 MeV lasted about one day, and four photons are at energies greater than 40 GeV. We show that the count rate of 100 MeV-100 GeV emission may be mainly accounted for by the forward shock synchrotron radiation and the inverse Compton radiation likely dominates at GeV-TeV energies. In particular, an inverse Compton radiation origin is favored for the ∼(95.3, 47.3, 41.4, 38.5, 32) GeV photons arriving at t ∼ (243, 256.3, 610.6, 3409.8, 34366.2) s after the trigger of Fermi-GBM. Interestingly, the external inverse Compton scattering of the prompt emission (the second episode, i.e., t ∼ 120-260 s) by the forward-shock-accelerated electrons is expected to produce a few γ-rays at energies above 10 GeV, while five were detected in the same time interval. A possible unified model for the prompt soft γ-ray, optical, and GeV emission of GRB 130427A, GRB 080319B, and GRB 090902B is outlined. Implications of the null detection of >1 TeV neutrinos from GRB 130427A by IceCube are discussed

Applications of Robust, Radiation Hard AlGaN Optoelectronic Devices in Space Exploration and High Energy Density Physics

Energy Technology Data Exchange (ETDEWEB)

Sun, K.

2011-05-04

This slide show presents: space exploration applications; high energy density physics applications; UV LED and photodiode radiation hardness; UV LED and photodiode space qualification; UV LED AC charge management; and UV LED satellite payload instruments. A UV LED satellite will be launched 2nd half 2012.

Development of dose monitoring system applicable to various radiations with wide energy ranges

International Nuclear Information System (INIS)

Sato, Tatsuhiko; Satoh, Daiki; Endo, Akira

2006-01-01

A new radiation dose monitor, designated as DARWIN (Dose monitoring system Applicable to various Radiations with WIde energy raNges), has been developed for real-time monitoring of doses in workspaces and surrounding environments of high energy accelerator facilities. DARWIN is composed of a phoswitch-type scintillation detector, which consists of liquid organic scintillator BC501A coupled with ZnS(Ag) scintillation sheets doped with 6 Li, and a data acquisition system based on a Digital-Storage-Oscilloscope. DARWIN has the following features: (1) capable of monitoring doses from neutrons, photons and muons with energies from thermal energy to 1 GeV, 150 keV to 100 MeV, and 1 MeV to 100 GeV, respectively, (2) highly sensitive with precision, and (3) easy to operate with a simple graphical user-interface. The performance of DARWIN was examined experimentally in several radiation fields. The results of the experiments indicated the accuracy and rapid response of DARWIN for measuring dose rates from neutrons, photons and muons with wide energies. With these properties, we conclude that DARWIN will be able to play a very important role for improving radiation safety in high energy accelerator facilities. (author)

A study on the apron shielding ratio according to electromagnetic radiation energy

Energy Technology Data Exchange (ETDEWEB)

Jang, Dong Gun; Lee, Sang Ho; Choi, Hyung Seok; Son, Joo Chul; Yoon, Chang Yong; Ji, Yung Sik; Cho, Yong In; Lee, Hong Je; Yang, Seoung Oh [Dept. of Nuclear Medicine, Dongnam Institute of Radiological and Medical Sciences Cancer Center, Busan (Korea, Republic of)

2014-12-15

The medical institution has been used electromagnetic radiation of various energy. But researchers are divided on whether using apron for radiation shielding will be effective or not. The purpose of present study was to analyze electromagnetic radiation shielding effect of apron by using Monte Carlo simulation. 1 MBq electromagnetic radiation was emitted from 10-500 keV at 10 keV increments in Monte Carlo simulation. Then shielded radiation dose difference was confirmed, when 0.25 mmPb shield use for shielding. As a results, shielding ratio was markedly decreased in high energy electromagnetic radiation. The radiation dose was inversely increased with 0.25 mmPb shielding.

A study on the apron shielding ratio according to electromagnetic radiation energy

International Nuclear Information System (INIS)

Jang, Dong Gun; Lee, Sang Ho; Choi, Hyung Seok; Son, Joo Chul; Yoon, Chang Yong; Ji, Yung Sik; Cho, Yong In; Lee, Hong Je; Yang, Seoung Oh

2014-01-01

The medical institution has been used electromagnetic radiation of various energy. But researchers are divided on whether using apron for radiation shielding will be effective or not. The purpose of present study was to analyze electromagnetic radiation shielding effect of apron by using Monte Carlo simulation. 1 MBq electromagnetic radiation was emitted from 10-500 keV at 10 keV increments in Monte Carlo simulation. Then shielded radiation dose difference was confirmed, when 0.25 mmPb shield use for shielding. As a results, shielding ratio was markedly decreased in high energy electromagnetic radiation. The radiation dose was inversely increased with 0.25 mmPb shielding

High-energy cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Gaisser, Thomas K. [Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States)]. E-mail: gaisser@bartol.udel.edu; Stanev, Todor [Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States)

2006-10-17

After a brief review of galactic cosmic rays in the GeV to TeV energy range, we describe some current problems of interest for particles of very high energy. Particularly interesting are two features of the spectrum, the knee above 10{sup 15} eV and the ankle above 10{sup 18} eV. An important question is whether the highest-energy particles are of extra-galactic origin and, if so, at what energy the transition occurs. A theme common to all energy ranges is use of nuclear abundances as a tool for understanding the origin of the cosmic radiation.

Individual monitoring in high-energy stray radiation fields

International Nuclear Information System (INIS)

Hoefert, M.; Stevenson, G.R.

1995-01-01

Due to the lack of passive or active devices that could be considered as personal dosemeters in high-energy stray fields one can at present only perform individual monitoring around high energy accelerators. Of all detectors currently available it is shown that the NTA film is the most suitable method for individually monitoring the neutron exposure of more than 3000 persons regularly, reliably, and cost effectively like at CERN. (author)

Characterization of radiation-cross-linked, high-density polyethylene for thermal energy storage

International Nuclear Information System (INIS)

Whitaker, R.B.; Craven, S.M.; Etter, D.E.; Jendrek, E.F.; Nease, A.B.

1983-01-01

Electron beam cross-linked high-density polyethylene (HDPE) pellets (DuPont Alathon, 0.93 MI) have been characterized for potential utility in thermal energy storage applications, before and after up to 500 melt-freeze cycles in ethylene glycol. Up to 95% of the HDPE's initial DSC differential scanning calorimetry Δ H/sub f/ value (44.7 cal/g) (at 1.25 0 C/min cooling rates) was retained up to 9.0 Mrad radiation dosage. Form-stability after 500 melt-freeze cycles was very good at this dosage level. X-ray diffraction measurements showed little difference between irradiated HDPE's and the unirradiated control, indicating that cross-linking occurred primarily in the amorphous regions. FTIR spectroscopy showed the pellets to be uniformly reacted. The ratios of the 965-cm -1 absorption band (trans RCH=CRH') to the 909-cm -1 band (RCH=CH 2 ) increased with increasing radiation dosage, up to 18 Mrad. Gel contents reached a maximum of 75% at the 13.5 Mrad dosage, indicating that other reactions, in addition to cross-linking, occurred at the highest (18 Mrad) dosage level. 15 references, 5 figures, 4 tables

Radiosensitization of high-Z compounds by medium-energy 160 kV vs. high-energy 6 MV X-rays for radiation therapy: Theoretical, in vitro and in vivo studies of platinum compounds activating glioma F98 cancer cells

Science.gov (United States)

Lim, S.; Pradhan, A.; Nahar, S.; Montenegro, M.; Barth, R.; Nakkula, R.; Turro, C.

2013-03-01

Energy dependence of X-ray irradiation of high-Z compounds for enhanced radiosensitization is explored thoeretically and via in vitro and in vivo experiments. The cell killing ability of medium-energy X-rays from 160 kV source are found to be more effective than 6 MV X-rays in activating high-Z contrast agents. Results are presented for a newly synthesized Pt compound, Pyridine Terpyridine Pt(II) Nitrate ([Pt(typ)(py)]) and carboplatin in treating F98 rat glioma. In-vitro results show considerable reduction in cell viability for radiosensitized cells irradiated with a 160 kV irradiator. Cells treated with 6 MV LINAC radiation find little variation with radiation dose. Maximum dose enhancement factors (DEFs) and minimum cancer cell survival fractions correspond to 50-200 keV range, and fall rapidly at higher energies. Theoretical calculations of photoelectric absorption vis-a-vis total scattering demonstrates this energy dependence. However, in vivo studies of rats treated with [Pt(tpy)(py)] had a severe negative neurotoxic response, confirmed by histopathological analysis. But subsequent in vivo studies using carboplatin showed very positive results in the treatment of F98 glioma bearing rats and potential clinical radiation therapy.

Bridging the Radiative Transfer Models for Meteorology and Solar Energy Applications

Science.gov (United States)

Xie, Y.; Sengupta, M.

2017-12-01

Radiative transfer models are used to compute solar radiation reaching the earth surface and play an important role in both meteorology and solar energy studies. Therefore, they are designed to meet the needs of specialized applications. For instance, radiative transfer models for meteorology seek to provide more accurate cloudy-sky radiation compared to models used in solar energy that are geared towards accuracy in clear-sky conditions associated with the maximum solar resource. However, models for solar energy applications are often computationally faster, as the complex solution of the radiative transfer equation is parameterized by atmospheric properties that can be acquired from surface- or satellite-based observations. This study introduces the National Renewable Energy Laboratory's (NREL's) recent efforts to combine the advantages of radiative transfer models designed for meteorology and solar energy applictions. A fast all-sky radiation model, FARMS-NIT, was developed to efficiently compute narrowband all-sky irradiances over inclined photovoltaic (PV) panels. This new model utilizes the optical preperties from a solar energy model, SMARTS, to computes surface radiation by considering all possible paths of photon transmission and the relevent scattering and absorption attenuation. For cloudy-sky conditions, cloud bidirectional transmittance functions (BTDFs) are provided by a precomputed lookup table (LUT) by LibRadtran. Our initial results indicate that FARMS-NIT has an accuracy that is similar to LibRadtran, a highly accurate multi-stream model, but is significantly more efficient. The development and validation of this model will be presented.

High-energy Emission from Nonrelativistic Radiative Shocks: Application to Gamma-Ray Novae

Science.gov (United States)

Vurm, Indrek; Metzger, Brian D.

2018-01-01

The observation of GeV gamma-rays from novae by Fermi/LAT demonstrates that the nonrelativistic radiative shocks in these systems can accelerate particles to energies of at least ∼10 GeV. The low-energy extension of the same nonthermal particle distribution inevitably gives rise to emission in the hard X-ray band. Above ≳ 10 {keV}, this radiation can escape the system without significant absorption/attenuation, and can potentially be detected by NuSTAR. We present theoretical models for hard X-ray and gamma-ray emission from radiative shocks in both leptonic and hadronic scenarios, accounting for the rapid evolution of the downstream properties due to the fast cooling of thermal plasma. We find that due to strong Coulomb losses, only a fraction of {10}-4{--}{10}-3 of the gamma-ray luminosity is radiated in the NuSTAR band; nevertheless, this emission could be detectable simultaneously with the LAT emission in bright gamma-ray novae with a ∼50 ks exposure. The spectral slope in hard X-rays is α ≈ 0 for typical nova parameters, thus serving as a testable prediction of the model. Our work demonstrates how combined hard X-ray and gamma-ray observations can be used to constrain properties of the nova outflow (velocity, density, and mass outflow rate) and particle acceleration at the shock. A very low X-ray to gamma-ray luminosity ratio ({L}{{X}}/{L}γ ≲ 5× {10}-4) would disfavor leptonic models for the gamma-ray emission. Our model can also be applied to other astrophysical environments with radiative shocks, including SNe IIn and colliding winds in massive star binaries.

Fundamental radiation effect on polymers energy transfer from radiation to polymer

International Nuclear Information System (INIS)

Seguchi, T.

2007-01-01

Polymer modification as cross-link, chain scission, and graft-polymerization by radiation is initiated by the quantum energy transferred from radiation to polymers. The active species for chemical reactions are produced through ionization or activation of polymer molecules for any radiation source. The energy transfer occurs mainly by ionic interaction between radiation and polymer molecule, and the contribution from the collision interaction is miner. The radiation of electromagnetic wave as X-ray or γ-ray generates the energetic electron which induces ionic interaction with polymer molecule. The energy loss profile along the penetration to polymer material is much different among the radiation sources of EB, γ-ray, and ion beams in the macroscopic mechanism. In this article, the behavior of single event, that is, the event induced by one electron, γ-ray, ion, and neutron is described by the macroscopic mechanism and by the microscopic mechanism. (authors)

Higher energy: is it necessary, is it worth the cost for radiation oncology?

Science.gov (United States)

Das, I J; Kase, K R

1992-01-01

The physical characteristics of the interactions of megavoltage photons and electrons with matter provide distinct advantages, relative to low-energy (orthovoltage) x rays, that lead to better radiation dose distributions in patients. Use of these high-energy radiations has resulted in better patient care, which has been reflected in improved radiation treatment outcome in recent years. But, as the desire for higher energy radiation beams increases, it becomes important to determine whether the physical characteristics that make megavoltage beams beneficial continue to provide a net advantage. It is demonstrated that, in fact, there is an energy range from 4 to 15 MV for photons and 4 to 20 MeV for electrons that is optimally suited for the treatment of cancer in humans. Radiation beams that exceed these maximum energies were found to add no advantage. This is because the costs (price of unit, installation, maintenance, shielding for neutron and photons) are not justified by either improved physical characteristics of the radiation (penetration, skin sparing, dose distribution) or treatment outcome. In fact, for photon beams some physical characteristics result in less desirable dose distributions, less accurate dosimetry, and increased safety problems as the energy increases for example, increasingly diffuse beam edges, loss of electron equilibrium, uncertainty in dose perturbations at interfaces, increased neutron contamination, and potential for higher personnel dose. The special features that make electron beams useful at lower energies, for example, skin sparing and small penetration, are lost at high energies. These physical factors are analyzed together with the economic factors related to radiation therapy patient care using megavoltage beams.

A method to detect ultra high energy electrons using earth's magnetic field as a radiator

Science.gov (United States)

Stephens, S. A.; Balasubrahmanyan, V. K.

1983-01-01

It is pointed out that the detection of electrons with energies exceeding a few TeV, which lose energy rapidly through synchrotron and inverse Compton processes, would provide valuable information on the distribution of sources and on the propagation of cosmic rays in the solar neighborhood. However, it would not be possible to measure the energy spectrum beyond a few TeV with any of the existing experimental techniques. The present investigation is, therefore concerned with the possibility of detecting electrons with energies exceeding a few TeV on the basis of the photons emitted through synchrotron radiation in the earth's magnetic field. Attention is given to the synchrotron radiation of electrons in the earth's magnetic field, detector response and energy estimation, and the characteristics of an ideal detector, capable of detecting photons with energies equal to or greater than 20 keV.

HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

Science.gov (United States)

Sohn, Jongdae; Lee, Jaejin; Min, Kyoungwook; Lee, Junchan; Lee, Seunguk; Lee, Daeyoung; Jo, Gyeongbok; Yi, Yu; Na, Gowoon; Kang, Kyung-In; Shin, Goo-Hwan

2018-05-01

Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0°. 45°, and 90°, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from 350 keV to 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.

Intercomparison of radiation protection devices in a high-energy stray neutron field. Part III: Instrument response

International Nuclear Information System (INIS)

Silari, M.; Agosteo, S.; Beck, P.; Bedogni, R.; Cale, E.; Caresana, M.; Domingo, C.; Donadille, L.; Dubourg, N.; Esposito, A.; Fehrenbacher, G.; Fernandez, F.; Ferrarini, M.; Fiechtner, A.; Fuchs, A.; Garcia, M.J.; Golnik, N.; Gutermuth, F.; Khurana, S.; Klages, Th.

2009-01-01

The European Commission has funded within its 6th Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organizational framework for this project was provided by the European radiation Dosimetry Group EURADOS. Work Package 6 of CONRAD dealt with 'complex mixed radiation fields at workplaces' and in this context it organised a benchmark exercise, which included both measurements and calculations, in a stray radiation field at a high-energy particle accelerator at GSI, Germany. The aim was to intercompare the response of several types of active detectors and passive dosemeters in a well-characterised workplace field. The Monte Carlo simulations of the radiation field and the experimental determination of the neutron spectra with various Bonner Sphere Spectrometers are discussed in Rollet et al. (2008) and in Wiegel et al. (2008). This paper focuses on the intercomparison of the response of the dosemeters in terms of ambient dose equivalent. The paper describes in detail the detectors employed in the experiment, followed by a discussion of the results. A comparison is also made with the H*(10) values predicted by the Monte Carlo simulations and those measured by the BSS systems.

Radiation protection around high energy proton accelerators

International Nuclear Information System (INIS)

Bourgois, L.

1996-01-01

Proton accelerators are intense radiation sources because of the particle beam itself, secondary radiation and structure activation. So radiation protection is required around these equipment during running time but even during downtime. This article presents some estimated values about structure and air activation and applies the Moyer model to get dose rate behind shielding. (A.C.)

High energy KrCl electric discharge laser

Science.gov (United States)

Sze, Robert C.; Scott, Peter B.

1981-01-01

A high energy KrCl laser for producing coherent radiation at 222 nm. Output energies on the order of 100 mJ per pulse are produced utilizing a discharge excitation source to minimize formation of molecular ions, thereby minimizing absorption of laser radiation by the active medium. Additionally, HCl is used as a halogen donor which undergoes a harpooning reaction with metastable Kr.sub.M * to form KrCl.

Respiration and phosphorylation in liver and kidney mitochondria of rats exposed to high-energy gamma and beta radiation

Energy Technology Data Exchange (ETDEWEB)

Mokhoreva, S I; Vetlugina, N S

1973-01-01

The effect of whole-body irradiation with ..gamma.. rays (radiation source /sup 60/Co) at 40 rad and ..beta.. rays (source, a linear accelerator, electron energy 25 MeV) at 43 rad on oxidative phosphorylation in liver and kidney mitochondria was studied in rats. Gamma radiation gradually slowed the esterification of phosphate and respiratory rate during the oxidation of succinate in the liver and kidney mitochondria. The decrease was largest on day 15 after irradiation. However, the P/O ratio did not decrease by more than 10 to 12 percent. Despite the oxidation of glutamate in the mitochondria, respiration, phosphate consumption, and P/O ratio scarcely changed. Irradiation with electrons slowed the rate of oxidation of succinate and glutamate in liver mitochondria within 3 to 7 days. Phosphate consumption decreased at the same time so that the P/O ratio remained unchanged. Beta irradiation had virtually no effect on liver mitochondria. There is a discussion of the mechanism of action of high-energy radiation on the phosphorylation system of the mitochondria.

Atomic Energy Society of Japan's support activities on radiation education

International Nuclear Information System (INIS)

Kudo, K.

2016-01-01

Educational Committee of AESJ supports the education about nuclear energy and radiation for elementary, secondary and senior high school students. It also supports professional nuclear engineer education and international radiation education. (author)

High energy irradiation of bacterial membrane vesicles

International Nuclear Information System (INIS)

De La Rosa, M.A.M.

1977-01-01

The interactions of membrane components and two well-defined transport systems in the E. coli ML 308-225 membrane vesicles with 60 Co gamma radiation were investigated. The results presented show that gamma radiation can monitor membrane components and functions of varying radiosensitivities. The possible application of high-energy radiation as a physical probe of membrane structure and functions is indeed promising

Apoptosis induced by high- and low-LET radiations

International Nuclear Information System (INIS)

Hendry, J.H.; Potten, C.S.; Merritt, A.

1995-01-01

Cell death after irradiation occurs by apoptosis in certain cell populations in tissues. The phenomenon also occurs after high linear energy transfer (LET) irradiation, and the relative biological effectiveness (RBE) is 3 to 4 (with respect to low-LET radiation and apoptosis in intestinal crypts) for neutrons with energies of 14 MeV and up to 600 MeV. It is thought that p53 plays a role in the phenomenon, as radiation-induced apoptosis is not observed in p53-null animals. (orig.)

Nuclear energy and radiation

International Nuclear Information System (INIS)

Myers, D.K.; Johnson, J.R.

1980-01-01

Both the light water reactor and the Canadian heavy water reactor systems produce electricity cheaply and efficiently. They produce some fissionable byproducts, which can be recycled to extend energy sources many-fold. Besides the production of electrical power, the nuclear industry produces various radioistopes used for treatment of cancer, in diagnostic procedures in nuclear medicine, in ionization smoke detectors, and as radioactive tracers with various technological applications including the study of the mechanisms of life. The increment in environmental radiation levels resulting from operation of nuclear power reactors represents a very small fraction of the radiation levels to which we are all exposed from natural sources, and of the average radiation exposures resulting from diagnostic procedures in the healing arts. The total health hazard of the complete nuclear power cycle is generally agreed to be smaller than the hazards associated with the generation of an equal amount of electricity from most other currently available sources of energy. The hazards from energy production in terms of shortened life expectancy are much smaller in all cases than the resulting increase in health and life expectancy. (auth)

Dose to radiation therapists from activation at high-energy accelerators used for conventional and intensity-modulated radiation therapy

International Nuclear Information System (INIS)

Rawlinson, J. Alan; Islam, Mohammad K.; Galbraith, Duncan M.

2002-01-01

The increased beam-on times which characterize intensity-modulated radiation therapy (IMRT) could lead to an increase in the dose received by radiation therapists due to induced activity. To examine this, gamma ray spectrometry was used to identify the major isotopes responsible for activation at a representative location in the treatment room of an 18 MV accelerator (Varian Clinac 21EX). These were found to be 28 Al, 56 Mn, and 24 Na. The decay of the dose rate measured at this location following irradiation was analyzed in terms of the known half-lives to yield saturation dose rates of 9.6, 12.4, and 6.2 μSv/h, respectively. A formalism was developed to estimate activation dose (μSv/week) due to successive patient irradiation cycles, characterized by the number of 18 MV fractions per week, F, the number of MU per fraction, M, the in-room time between fractions, t d (min), and the treatment delivery time t r ' (min). The results are represented by the sum of two formulas, one for the dose from 28 Al≅1.8x10 -3 F M (1-e -0.3t r ' )/t r ' and one for the dose from the other isotopes ≅1.1x10 -6 F 1.7 Mt d . For conventional therapy doses are about 60 μ Sv/week for an 18 MV workload of 60 000 MU/week. Irradiation for QA purposes can significantly increase the dose. For IMRT as currently practiced, lengthy treatment delivery times limit the number of fractions that can be delivered per week and hence limit the dose to values similar to those in conventional therapy. However for an IMRT regime designed to maximize patient throughput, doses up to 330 μSv/week could be expected. To reduce dose it is recommended that IMRT treatments should be delivered at energies lower than 18 MV, that in multienergy IMRT, high-energy treatments should be scheduled in the latter part of the day, and that equipment manufacturers should strive to minimize activation in the design of high-energy accelerators

The effect of magnetic field strength on the time evolution of high energy bremsstrahlung radiation created by an electron cyclotron resonance ion source

Energy Technology Data Exchange (ETDEWEB)

Ropponen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)], E-mail: tommi.ropponen@phys.jyu.fi; Tarvainen, O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Jones, P.; Peura, P.; Kalvas, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland); Suominen, P. [Prizztech Ltd/Magnet Technology Centre, Tiedepuisto 4, FI-28600 Pori (Finland); Koivisto, H.; Arje, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)

2009-03-11

An electron cyclotron resonance (ECR) ion source is one of the most used ion source types for high charge state heavy ion production. In ECR plasma the electrons are heated by radio frequency microwaves in order to provide ionization of neutral gases. As a consequence, ECR heating also generates very high electron energies (up to MeV region) which can produce a vast amount of bremsstrahlung radiation causing problems with radiation shielding and heating superconducting cryostat of an ECR ion source. To gain information about the time evolution of the electron energies in ECR plasma radial bremsstrahlung measurements were performed. JYFL 14 GHz ECR ion source was operated in pulsed mode and time evolution measurements were done with different axial magnetic field strengths with oxygen and argon plasmas. Bremsstrahlung data were analyzed with a time interval of 2 ms yielding information at unprecedented detail about the time evolution of high energy bremsstrahlung radiation from an ECR ion source. It was observed, for example, that reaching the steady state phase of the plasma bremsstrahlung requires several hundred milliseconds and the steady state time can be different with different gases.

Radiation metabolomics : a window to high throughput radiation biodosimetry

International Nuclear Information System (INIS)

Rana, Poonam

2016-01-01

In the event of an intentional or accidental release of ionizing radiation in a densely populated area, timely assessment and triage of the general population for radiation exposure is critical. In particular, a significant number of victims may sustain radiation injury, which increases mortality and worsens the overall prognosis of victims from radiation trauma. Availability of a high-throughput noninvasive in vivo biodosimetry tool for assessing the radiation exposure is of particular importance for timely diagnosis of radiation injury. In this study, we describe the potential NMR techniques in evaluating the radiation injury. NMR is the most versatile technique that has been extensively used in the diverse fields of science since its discovery. NMR and biomedical sciences have been going hand in hand since its application in clinical imaging as MRI and metabolic profiling of biofluids was identified. We have established an NMR based metabonomic and in vivo spectroscopy approach to analyse and identify metabolic profile to measure metabolic fingerprint for radiation exposure. NMR spectroscopy experiments were conducted on urine and serum samples collected from mice irradiated with different doses of radiation. Additionally, in vivo NMR spectroscopy was also performed in different region of brains post irradiation in animal model. A number of metabolites associated with energy metabolism, gut flora metabolites, osmolytes, amino acids and membrane metabolism were identified in serum and urine metabolome. Our results illustrated a metabolic fingerprint for radiation exposure that elucidates perturbed physiological functions. Quantitative as well as multivariate analysis/assessment of these metabolites demonstrated dose and time dependent toxicological effect. In vivo spectroscopy from brain showed radiation induced changes in hippocampus region indicating whole body radiation had striking effect on brain metabolism as well. The results of the present work lay a

High-resolution imaging of coronary calcifications by intense low-energy fluoroscopic X-ray obtained from synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Ohtsuka, S.; Sugishita, Y.; Takeda, T.; Itai, Y.; Tada, J.; Hyodo, K.; Ando, M. [Inst. of Clinical Medicine, Univ. of Tsukuba, Ibaraki (Japan). Dept. of Cardiology

2000-07-01

In order to obtain an intense monochromatic low-energy X-ray from synchrotron radiation (SR) and apply it to detect coronary calcifications, the SR beam was reflected with a silicon crystal to be expanded (150 mm in height and 80 mm in width) and to be monochromatized at an energy level of 37 keV. The X-ray was intermittently irradiated to obtain dynamic imaging of 30 images/s. Images were recorded by a digital fluorography system. The low-energy X-ray from SR sharply visualized calcification of coronary arteries, while conventional X-ray could not visualize coronary calcification. The intense monochromatic low-energy X-ray from SR is sensitive, has high-resolution for imaging coronary calcification and may serve as a screening method for coronary artery disease.

Calibration of solid state nuclear track detectors at high energy ion beams for cosmic radiation measurements: HAMLET results

International Nuclear Information System (INIS)

Szabó, J.; Pálfalvi, J.K.

2012-01-01

The MATROSHKA experiments and the related HAMLET project funded by the European Commission aimed to study the dose burden of the crew working on the International Space Station (ISS). During these experiments a human phantom equipped with several thousands of radiation detectors was exposed to cosmic rays inside and outside the ISS. Besides the measurements realized in Earth orbit, the HAMLET project included also a ground-based program of calibration and intercomparison of the different detectors applied by the participating groups using high-energy ion beams. The Space Dosimetry Group of the Centre for Energy Research (formerly Atomic Energy Research Institute) participated in these experiments with passive solid state nuclear track detectors (SSNTDs). The paper presents the results of the calibration experiments performed in the years 2008–2011 at the Heavy Ion Medical Accelerator (HIMAC) of the National Institute of Radiological Sciences (NIRS), Chiba, Japan. The data obtained serve as update and improvement for the previous calibration curves which are necessary for the evaluation of the SSNTDs exposed in unknown space radiation fields.

Calibration of solid state nuclear track detectors at high energy ion beams for cosmic radiation measurements: HAMLET results

Energy Technology Data Exchange (ETDEWEB)

Szabo, J., E-mail: julianna.szabo@energia.mta.hu [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary); Palfalvi, J.K. [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary)

2012-12-01

The MATROSHKA experiments and the related HAMLET project funded by the European Commission aimed to study the dose burden of the crew working on the International Space Station (ISS). During these experiments a human phantom equipped with several thousands of radiation detectors was exposed to cosmic rays inside and outside the ISS. Besides the measurements realized in Earth orbit, the HAMLET project included also a ground-based program of calibration and intercomparison of the different detectors applied by the participating groups using high-energy ion beams. The Space Dosimetry Group of the Centre for Energy Research (formerly Atomic Energy Research Institute) participated in these experiments with passive solid state nuclear track detectors (SSNTDs). The paper presents the results of the calibration experiments performed in the years 2008-2011 at the Heavy Ion Medical Accelerator (HIMAC) of the National Institute of Radiological Sciences (NIRS), Chiba, Japan. The data obtained serve as update and improvement for the previous calibration curves which are necessary for the evaluation of the SSNTDs exposed in unknown space radiation fields.

High-power beam-based coherently enhanced THz radiation source

Directory of Open Access Journals (Sweden)

Yuelin Li (李跃林

2008-08-01

Full Text Available We propose a compact Smith-Purcell radiation device that can potentially generate high average power THz radiation with high conversion efficiency. The source is based on a train of short electron bunches from an rf photoemission gun at an energy of a few MeV. Particle tracking simulation and analysis show that, with a beam current of 1 mA, it is feasible to generate hundreds of watts of narrow-band THz radiation at a repetition rate of 1 MHz.

Dose conversion coefficients for high-energy photons, electrons, neutrons and protons

International Nuclear Information System (INIS)

Sakamoto, Yukio

2005-01-01

Dose conversion coefficients for photons, electrons and neutrons based on new ICRP recommendations were cited in the ICRP Publication 74, but the energy ranges of these data were limited and there are no data for high energy radiations produced in accelerator facilities. For the purpose of designing the high intensity proton accelerator facilities at JAERI, the dose evaluation code system of high energy radiations based on the HERMES code was developed and the dose conversion coefficients of effective dose were evaluated for photons, neutrons and protons up to 10 GeV, and electrons up to 100 GeV. The dose conversion coefficients of effective dose equivalent were also evaluated using quality factors to consider the consistency between radiation weighting factors and Q-L relationship. The effective dose conversion coefficients obtained in this work were in good agreement with those recently evaluated by using FLUKA code for photons and electrons with all energies, and neutrons and protons below 500 MeV. There were some discrepancy between two data owing to the difference of cross sections in the nuclear reaction models. The dose conversion coefficients of effective dose equivalents for high energy radiations based on Q-L relation in ICRP Publication 60 were evaluated only in this work. The previous comparison between effective dose and effective dose equivalent made it clear that the radiation weighting factors for high energy neutrons and protons were overestimated and the modification was required. (author)

Radiation losses and global energy balance for Ohmically heated discharges in ASDEX

International Nuclear Information System (INIS)

Mueller, E.R.; Behringer, K.; Niedermeyer, H.

1982-01-01

Global energy balance, radiation profiles and dominant impurity radiation sources are compared for Ohmically heated limiter and divertor discharges in the ASDEX tokamak. In discharges with a poloidal stainless-steel limiter, total radiation from the plasma is the dominant energy loss channel. The axisymmetric divertor reduces this volume-integrated radiation to 30-35% of the heating power and additional Ti-gettering halves it again to 10-15%. Local radiation losses in the plasma centre, which are mainly due to the presence of iron impurity ions, are reduced by about one order of magnitude. In high-current (Isub(p) = 400 kA) and high-density (nsub(e)-bar = 6 x 10 13 cm -3 ) ungettered divertor discharges, up to 55% of the heating power is dumped into a cold-gas target inside the divertor chambers. The bolometrically detected volume power losses in the chambers can mainly be attributed to neutral hydrogen atoms with kinetic energies of a few eV. In this parameter range, the divertor plasma is dominated by inelastic molecular and atomic processes, the main process being Franck-Condon dissociation of H 2 molecules. (author)

Chambers nuclear energy and radiation dictionary

International Nuclear Information System (INIS)

Walker, P.M.B.

1992-01-01

This Dictionary is designed to make it easier for those who are concerned about nuclear power and radiation to learn more about nuclear energy and to come to an informed opinion. The first two of the 11 chapters which precede the dictionary proper describe the properties of the atomic nucleus which make nuclear energy possible and then the problems which have to be overcome in harnessing this energy. The next two chapters discuss the many different kinds of power stations which rely on fission and then the methods of fusion which may produce power in the next century. There are then two chapters on nuclear safety and on the production and enrichment of uranium fuel, together with methods for its eventual disposal. These are followed by a chapter on nuclear bombs of various kinds and one on how nuclear and other forms of radiation can be detected. There is then a chapter which relates the radiation resulting from nuclear fission to other kinds of radiation. The next chapter discusses some basic biology particularly cancer. Finally, the biological effects of radiation are described before comparing the amounts of man-made radiation to that which comes naturally from outer space and from the rocks beneath us. This then leads to the radiation limits which are determined by the various regulartory authorities and the kinds of evidence upon which their decisions are based. (Author)

High energy HF pulsed lasers

International Nuclear Information System (INIS)

Patterson, E.L.; Gerber, R.A.

1976-01-01

Recent experiments show that pulsed HF lasers are capable of producing high energy with good efficiency. Preliminary experiments show that the laser radiation from the high-gain medium can be controlled with a low-power probe laser beam or with low-level feedback. These results indicate that the HF laser may have potential for second-generation laser fusion experiments

New approach to high energy SU/sub 2L/ /times/ U1 radiative corrections

International Nuclear Information System (INIS)

Ward, B.F.L.

1988-07-01

We present a new approach to SU/sub 2L/ /times/ U 1 radiative corrections at high energies. Our approach is based on the infrared summation methods of Yennie, Frautschi and Suura, taken together with the Weinberg-'t Hooft renormalization group equation. Specific processes which have been realized via explicit Monte Carlo algorithms are e + e/sup /minus// → f/bar f/' + n(γ), f = μ, /tau/, d, s, u, c, b or t and e + e/sup /minus// → e + e/sup /minus// + n(γ), where n(γ), denotes multiple photo emission on an event-by-event basis. Exemplary Monte Carlo data are presented. 16 refs., 4 figs

Enhancing radiative energy transfer through thermal extraction

Directory of Open Access Journals (Sweden)

Tan Yixuan

2016-06-01

Full Text Available Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a. In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics.

Radiative inflation and dark energy

International Nuclear Information System (INIS)

Di Bari, Pasquale; King, Stephen F.; Luhn, Christoph; Merle, Alexander; Schmidt-May, Angnis

2011-01-01

We propose a model based on radiative symmetry breaking that combines inflation with dark energy and is consistent with the Wilkinson Microwave Anisotropy Probe 7-year regions. The radiative inflationary potential leads to the prediction of a spectral index 0.955 S < or approx. 0.967 and a tensor to scalar ratio 0.142 < or approx. r < or approx. 0.186, both consistent with current data but testable by the Planck experiment. The radiative symmetry breaking close to the Planck scale gives rise to a pseudo Nambu-Goldstone boson with a gravitationally suppressed mass which can naturally play the role of a quintessence field responsible for dark energy. Finally, we present a possible extra dimensional scenario in which our model could be realized.

High energy radiation fluences in the ISS-USLab: Ion discrimination and particle abundances

International Nuclear Information System (INIS)

Zaconte, Veronica; Casolino, Marco; Di Fino, Luca; La Tessa, Chiara; Larosa, Marianna; Narici, Livio; Picozza, Piergiorgio

2010-01-01

The ALTEA (Anomalous Long Term Effects on Astronauts) detector was used to characterize the radiation environment inside the USLab of the International Space Station (ISS), where it measured the abundances of ions from Be to Fe. We compare the ALTEA results with Alteino results obtained in the PIRS module of the Russian segment of the ISS, and normalize to the high energy Si abundances given by Simpson. These are the first particle spectral measurements, which include ions up to Fe, performed in the USLab. The small differences observed between those made inside the USLab and the Simpson abundances can be attributed to the transport through the spacecraft hull. However, the low abundance of Fe cannot be attributed to only this process.

Generating high-power short terahertz electromagnetic pulses with a multifoil radiator.

Science.gov (United States)

Vinokurov, Nikolay A; Jeong, Young Uk

2013-02-08

We describe a multifoil cone radiator capable of generating high-field short terahertz pulses using short electron bunches. Round flat conducting foil plates with successively decreasing radii are stacked, forming a truncated cone with the z axis. The gaps between the foil plates are equal and filled with some dielectric (or vacuum). A short relativistic electron bunch propagates along the z axis. At sufficiently high particle energy, the energy losses and multiple scattering do not change the bunch shape significantly. When passing by each gap between the foil plates, the electron bunch emits some energy into the gap. Then, the radiation pulses propagate radially outward. For transverse electromagnetic waves with a longitudinal (along the z axis) electric field and an azimuthal magnetic field, there is no dispersion in these radial lines; therefore, the radiation pulses conserve their shapes (time dependence). At the outer surface of the cone, we have synchronous circular radiators. Their radiation field forms a conical wave. Ultrashort terahertz pulses with gigawatt-level peak power can be generated with this device.

Radiation damage in molybdenum and tungsten in high neutron fluxes

International Nuclear Information System (INIS)

Veljkovic, S.; Milasin, N.

1964-01-01

The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

Radiation damage in molybdenum and tungsten in high neutron fluxes

Energy Technology Data Exchange (ETDEWEB)

Veljkovic, S; Milasin, N [Institute of Nuclear Sciences Boris Kidric, Department of Reactor Materials, Vinca, Beograd (Serbia and Montenegro)

1964-04-15

The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

A study on radiation safety measures for the use of high-energy beta-ray sources in medical fields

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Woo; Yang, Jeong Seon; Kim, Hyeon Jo [Cheju National Univ., Cheju (Korea, Republic of)

2000-12-15

The scope of this study consists of : an investigation of the current application status of medical radioisotopes, Sr-90, Ho-166, Re-188, which emit beta-rays of energy greater than 1.5 Mev, analyses of the environments under which the above isotopes are used, estimation of personal radiation doses by using the MCNP-4C computer code for the situations in which high radiation doses might be probable, review of the USA's regulations related to safe use of the radioisotopes, investigation of past over-expose cases reported in the internet, analysis of the current domestic regulations, suggestion of safety measures necessary for the use of the radioisotopes.

High thermal efficiency x-ray energy conversion scheme for advanced fusion reactors

International Nuclear Information System (INIS)

Quimby, D.C.; Taussig, R.T.; Hertzberg, A.

1977-01-01

This paper reports on a new radiation energy conversion scheme which appears to be capable of producing electricity from the high quality x-ray energy with efficiencies of 60 to 70 percent. This new reactor concept incorporates a novel x-ray radiation boiler and a new thermal conversion device known as an energy exchanger. The low-Z first walls of the radiation boiler are semi-transparent to x-rays, and are kept cool by incoming working fluid, which is subsequently heated to temperatures of 2000 to 3000 0 K in the interior of the boiler by volumetric x-ray absorption. The radiation boiler may be a compact part of the reactor shell since x-rays are readily absorbed in high-Z materials. The energy exchanger transfers the high-temperature working fluid energy to a lower temperature gas which drives a conventional turbine. The overall efficiency of the cycle is characterized by the high temperature of the working fluid. The high thermal efficiencies which appear achievable with this cycle would make an otherwise marginal advanced fusion reactor into an attractive net power producer. The operating principles, initial conceptual design, and engineering problems of the radiation boiler and thermal cycle are presented

Response of high Tc superconducting Josephson junction to nuclear radiation

International Nuclear Information System (INIS)

Ding Honglin; Zhang Wanchang; Zhang Xiufeng

1992-10-01

The development of nuclear radiation detectors and research on high T c superconducting nuclear radiation detectors are introduced. The emphases are the principle of using thin-film and thick-film Josephson junctions (bridge junction) based on high T c YBCO superconductors to detect nuclear radiation, the fabrication of thin film and thick-film Josephson junction, and response of junction to low energy gamma-rays of 59.5 keV emitted from 241 Am and beta-rays of 546 keV. The results show that a detector for measuring nuclear radiation spectrum made of high T c superconducting thin-film or thick-film, especially, thick-film Josephson junction, certainly can be developed

Present status of Radiation and Nuclear Education at High School in Japan

International Nuclear Information System (INIS)

Kudo, Kazuhiko

1999-01-01

A special committee for 'Radiation and Nuclear Education' made an investigation into textbooks for social and science courses at high school in 1996. The committee concluded that descriptions of subjects related to energy, radiation and nuclear power in textbooks should be more substantial . In textbooks for social course, nuclear power was described from the point of view of resource, energy and environment. Some of the textbooks described that Chernobyl power plant's accident and nuclear weapons testing contaminated and destructed the earth environment. Descriptions about nuclear power were perceptional and one-sided . In textbooks for science course, subjects related to radiation, nucleus, nuclear reactor and nuclear power plant were described in detail to a certain extent . Descriptions about radiation hazard and radiation utilization were objective and balanced. In order that high school students can understand objectively nuclear power as a energy resource and conservation of the earth environment, the committee recommended the government course guidelines to be revised. (M. Suetake)

Dosimetry of low-energy beta radiation

International Nuclear Information System (INIS)

Borg, J.

1996-08-01

Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy β radiation field were studied and evaluated in this project. The four different techniques included were β spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy β radiation field a moderated spectrum from a 14 C source (E β , max =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 μm in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for 147 Pm depth-dose profiles is also suitable for β radiation from 14 C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to β radiation for radiation fields with maximum β energies ranging from 67 keV to 2.27 MeV is reported. For maximum β energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a β dose higher than about 10 μGy can be measured with these dosemeters to within 0 to -20% independently of the βenergy for E β , max values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs

Radio observations of a galactic high energy gamma-ray source

Energy Technology Data Exchange (ETDEWEB)

Giacani, E.; Rovero, A.C. [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina)

2001-10-01

PSR B1706-44 is one of the very few galactic pulsars that has been discovered at TeV energies. PSR B1706-44 has been also detected in the X-ray domain. It has been suggested that the high energy radiation could be due to inverse Compton radiation from a pulsar wind nebula (PWN). It was reported on VLA high-resolution observations of a region around the pulsar PSR B1706-44 at 1.4, 4.8 and 8.4 GHz. The pulsar appears embedded in a synchrotron nebula. It was proposed that this synchrotron nebula is the radio counterpart of the high energy emission powered by the spin-down energy of the pulsar.

Ultra high energy cosmic rays

International Nuclear Information System (INIS)

Watson, A.A.

1986-01-01

Cosmic radiation was discovered 70 years ago but its origin remains an open question. The background to this problem is outlined and attempts to discover the origin of the most energetic and rarest group above 10 15 eV are described. Measurements of the energy spectrum and arrival direction pattern of the very highest energy particles, mean energy about 6 x 10 19 eV, are used to argue that these particles originate outside our galaxy. Recent evidence from the new field of ultra high energy γ-ray astronomy are discussed in the context of a galactic origin hypothesis for lower energy cosmic rays. (author)

High-speed Light Peak optical link for high energy applications

Energy Technology Data Exchange (ETDEWEB)

Chang, F.X. [Academia Sinica, Taipei, Taiwan (China); Chiang, F. [FOCI Fiber Optic Comm., Inc., Hsinchu, Taiwan (China); Deng, B. [Hubei Polytechnic University, Huangshi, Hubei (China); Southern Methodist University, Dallas, TX (United States); Hou, J. [FOCI Fiber Optic Comm., Inc., Hsinchu, Taiwan (China); Hou, S., E-mail: suen@gate.sinica.edu.tw [Academia Sinica, Taipei, Taiwan (China); Liu, C.; Liu, T. [Southern Methodist University, Dallas, TX (United States); Teng, P.K. [Academia Sinica, Taipei, Taiwan (China); Wang, C.H. [National United University, Miaoli, Taiwan (China); Xu, T. [Shandong University, Ji' nan (China); Southern Methodist University, Dallas, TX (United States); Ye, J. [Southern Methodist University, Dallas, TX (United States)

2014-11-21

Optical links provide high speed data transmission with low mass fibers favorable for applications in high energy experiments. We report investigation of a compact Light Peak optical engine designed for data transmission at 4.8 Gbps. The module is assembled with bare die VCSEL, PIN diodes and a control IC aligned within a prism receptacle for light coupling to fiber ferrule. Radiation damage in the receptacle was examined with {sup 60}Co gamma ray. Radiation induced single event effects in the optical engine were studied with protons, neutrons and X-ray tests.

High energy chemistry. Modern state and trends in development

International Nuclear Information System (INIS)

Pikaev, A.K.

1990-01-01

In the review modern state of studies in the field of high energy chemistry is considered. The most important achievements and problems of further development of radiation chemistry, plasmochemistry, photochemistry, laser chemistry and some other branches of high energy chemistry are discussed

Metformin radiosensitization effect of low and high linear energy transfer radiation in HCC

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Ho; Jung, Won Gyun [Division of Heavy Ion Clinical Research, Korea University, Seoul (Korea, Republic of); Kim, Mi Sook; Cho, Chul Koo; Jeong, Youn Kyoung [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2014-04-15

Metformin (1,1-dimethylbiguanide hydrochloride), the most widely used treatment for type 2 diabetes, provides a good tolerability profile and low cost and has recently sparked keen interest as a potential anticancer agent. Recent evidence has suggested Metformin provides a synergistic benefit with chemotherapy or radiotherapy against certain cancers in several clinical cohort studies.Treatment response rates are higher in patients treated with metformin in cohort studies of breast cancer treated with neoadjuvant chemotherapy in head and neck cancer treated with radiation and in esophageal cancer treated with chemoradiotherapy. As the sensitizing effect of Metformin in HCC has been characterized in vitro and in vivo, we investigated the radio-sensitizing effect of Metformin in HCC cells in combination with γ-ray (low LET) and neutron (high LET) radiation. The radiosensitizing effect of Metformin was much higher in neutron-irradiated than in γ -irradiated cell lines. Fortunately, Metformin had little effect on normal tissues. Our studies revealed no interaction between Metformin and radiation in normal hepatocytes. High LET radiation,including neutron and carbon ion, would produce more complicated and different cellular effects; indeed, the molecular biological mechanism of high LET radiation remains a topic of investigation.

Metformin radiosensitization effect of low and high linear energy transfer radiation in HCC

International Nuclear Information System (INIS)

Kim, Eun Ho; Jung, Won Gyun; Kim, Mi Sook; Cho, Chul Koo; Jeong, Youn Kyoung

2014-01-01

Metformin (1,1-dimethylbiguanide hydrochloride), the most widely used treatment for type 2 diabetes, provides a good tolerability profile and low cost and has recently sparked keen interest as a potential anticancer agent. Recent evidence has suggested Metformin provides a synergistic benefit with chemotherapy or radiotherapy against certain cancers in several clinical cohort studies.Treatment response rates are higher in patients treated with metformin in cohort studies of breast cancer treated with neoadjuvant chemotherapy in head and neck cancer treated with radiation and in esophageal cancer treated with chemoradiotherapy. As the sensitizing effect of Metformin in HCC has been characterized in vitro and in vivo, we investigated the radio-sensitizing effect of Metformin in HCC cells in combination with γ-ray (low LET) and neutron (high LET) radiation. The radiosensitizing effect of Metformin was much higher in neutron-irradiated than in γ -irradiated cell lines. Fortunately, Metformin had little effect on normal tissues. Our studies revealed no interaction between Metformin and radiation in normal hepatocytes. High LET radiation,including neutron and carbon ion, would produce more complicated and different cellular effects; indeed, the molecular biological mechanism of high LET radiation remains a topic of investigation

Energy window selection for a radiation signal processing system

International Nuclear Information System (INIS)

Knoll, G.F.; Schrader, M.E.

1986-01-01

This invention provides an apparatus and method for selecting only meaningful information from signals produced by Anger-type radioisotope cameras producing positional information. It is an improvement in the means for determining energy threshold values as a function of radiation event positional information. The establishment of an energy threshold table begins by flooding the camera face with a uniform source of radiation and utilizing the pre-established spatial translation table to reposition detected radiation events according to their true spatial element coordinates. A histogram is compiled for each spatial element, the histogram comprising the number of radiation events occurring at several discrete energy levels. A peak centroid value is then determined for each element, and an initial energy window is set. Next, a specified region of the camera field of view is inspected to determine a target sum of radiation events to be accepted by each element, setting a standard for adjusting the energy windows of each element. Using this standard, the energy window for each element is progressively adapted so that each will accept nearly the same number of radiation events or counts in response to a flood or calibration image. Finally the energy window for each true spatial element is translated back to its apparent spatial element and incorporated into an energy threshold table accessible by the apparent spatial coordinates of each radiation event

Development of radiation-resisting high molecular-weight materials

International Nuclear Information System (INIS)

Nakagawa, Tsutomu

1976-01-01

The excellent radiation-resisting polyvinyl chloride developed at the opportunity of the research on the relationships between the protection of living body and the polymer-technological protection from radiation is reviewed. The report is divided into four main parts, namely 1) the change in the molecular arrangement of market-available, high molecular-weight materials by gamma-ray irradiation, 2) the protection of high molecular-weight materials from radiation, 3) the relationships between the biological radiation-protective substances and the change to radiation-resisting property of synthesized high molecular-weight substances, and 4) the development of the radiation-resisting high molecular-weight materials as metal-collecting agents. Attention is paid to the polyvinyl chloride having N-methyl-dithio-carbamate radical (PMD), synthesized by the author et. al., that has excellent radiation-resisting property. PMD has some possibility to form thiol- and amino-radicals necessary to protect living things from radiation. It is believed that the protection effects of N-methyl-dithio-carbamate radical are caused by the relatively stable S radical produced by the energy transfer. PMD film is suitable for the irradiation of foods, because it hardly changes the permeability of oxygen and carbon dioxide. PMD produces mercaptide or chelate. A new metal-collecting agent (PSDC) having reactivity with the metallic ions with radiation-resisting property was developed, which is derived from polyvinyl chloride and sodium N-methyl-N-carboxy-methyl-dithio-carbamate. (Iwakiri, K.)

High LET radiation and mechanism of DNA damage repair

International Nuclear Information System (INIS)

Furusawa, Yoshiya

2004-01-01

Clarifying the mechanism of repair from radiation damage gives most important information on radiation effects on cells. Approximately 10% of biological experiments groups in Heavy Ion Medical Accelerator in Chiba (HIMAC) cooperative research group has performed the subject. They gave a lot of new findings on the mechanism, and solved some open questions. The reason to show the peak of relative biological effectiveness RBE at around 100-200 keV/μm causes miss-repair of DNA damage. Sub-lethal damage generated by high linear energy transfer (LET) radiation can be repaired fully. Potentially lethal damages by high-LET radiation also repaired, but the efficiency decreased with the LET, and so on. (author)

Simulation and measurements of the response of an air ionisation chamber exposed to a mixed high-energy radiation field

International Nuclear Information System (INIS)

Vincke, H.; Forkel-Wirth, D.; Perrin, D.; Theis, C.

2005-01-01

CERN's radiation protection group operates a network of simple and robust ionisation chambers that are installed inside CERN's accelerator tunnels. These ionisation chambers are used for the remote reading of ambient dose rate equivalents inside the machines during beam-off periods. This Radiation Protection Monitor for dose rates due to Induced Radioactivity ('PMI', trade name: PTW, Type 34031) is a non-confined air ionisation plastic chamber which is operated under atmospheric pressure. Besides its current field of operation it is planned to extend the use of this detector in the Large Hadron Collider to measure radiation under beam operation conditions to obtain an indication of the machine performance. Until now, studies of the PMI detector have been limited to the response to photons. In order to evaluate its response to other radiation components, this chamber type was tested at CERF, the high-energy reference field facility at CERN. Six PMI detectors were installed around a copper target being irradiated by a mixed hadron beam with a momentum of 120 GeV c -1 . Each of the chosen detector positions was defined by a different radiation field, varying in type and energy of the incident particles. For all positions, detailed measurements and FLUKA simulations of the detector response were performed. This paper presents the promising comparison between the measurements and simulations and analyses the influence of the different particle types on the resulting detector response. (authors)

Synergy between low and high energy radical femtochemistry

International Nuclear Information System (INIS)

Gauduel, Y A

2011-01-01

The deleterious effects of ionizing radiation on integrated biological targets being dependent on the spatio-temporal distribution of short-lived radical processes, a thorough knowledge of these early events requires a real-time probing in the range 10 -15 - 10 -10 s. This manuscript review is focused on the synergy that exists between low (1-10 eV) and high (MeV) energy radiation femtochemistry (LERF, HERF respectively). The synergy remains crucial for the investigation of primary radical processes that take place within the prethermal regime of low energy secondary electrons. The quantum character of very-short lived electron in a prehydrated configuration provides a unique sub-nanometric probe to spatially explore some early radiation-induced biomolecular damage. This approach would foreshadow the development of innovative applications for spatio-temporal radiation biology such as, i) a highly-selective pro-drug activation using well-defined quantum states of short-lived radicals, ii) the real-time nanodosimetry in biologically relevant environments, and iii) the ultrashort irradiation of living cells.

Surface dose measurements under stretched, perforated thermoplast sheets and under protective wound dressings for high energy photon radiation

International Nuclear Information System (INIS)

Staudenraus, J.; Christ, G.

2000-01-01

Patient fixation masks made of perforated thermoplast sheets are widely used in radiotherapy. These masks in particular serve to immobilize the head and neck region during radiation treatment. We placed samples made of differently stretched, perforated mask material on the surface of a white polystyrene (RW3) phantom and measured for high energy photon beams from Co-60 radiation up to 25 MV bremsstrahlung the dose increase resulting from the build-up under the hole and bridge areas. Depending on the energy of the incident beam and the thickness of the stretched mask material we observed a dose increase under the bridges at the phantom surface of 55% up to 140% compared to the dose without a layer of mask material. Under a hole the dose increase is almost half the value found under a bridge. However, deeper than 1 mm under the phantom surface this difference in dose increase under holes and bridges decreases to less than 10%. The mean dose increase under a perforated thermoplast sheet is lower than the dose increase under a homogeneous sheet made of the same material with the same mean thickness. Radiation induced skin lesions or an ulcerating tumour, respectively, may require a protective wound dressing under a patient fixation mask during radiation therapy. Choosing a thin hydrocolloid wound dressing the additional dose increase of the skin, compared to the dose increase due to the fixation mask, can be kept low. (orig.) [de

Observation of high-power coherent synchrotron radiation in the THz region from the JAEA energy recovery linac

International Nuclear Information System (INIS)

Takahashi, Toshiharu; Okuda, Shuichi; Minehara, Eisuke J.; Hajima, Ryoichi; Sawamura, Masaru; Nagai, Ryoji; Kikuzawa, Nobihiro; Iijima, Hokuto; Nishitani, Tomohiro; Nishimori, Nobuyuki

2007-01-01

The energy recovery linac (ERL) is able to generate high-power coherent synchrotron radiation (CSR) in the terahertz and the millimeter-wave regions, because it produces shorter bunches than usual storage rings and a higher current than conventional linacs. The spectrum of CSR has been measured at the JAEA-ERL in the wavenumber range from 0.5 to 15 cm -1 . The detected power was 2x10 -4 W/cm -1 at 2.5 cm -1 for the average beam current of 17.7 μA. When the infrared FEL was operated with the undulator in the ERL, the CSR spectrum was shifted to the longer wavelengths because of the energy broadening of the electron beam. (author)

Mouse fecal microbiome after exposure to high LET radiation

Data.gov (United States)

National Aeronautics and Space Administration — Space travel is associated with continuous low-dose-rate exposure to high Linear Energy Transfer (LET) radiation. Pathophysiological manifestations after low-dose...

High energy XeBr electric discharge laser

Science.gov (United States)

Sze, Robert C.; Scott, Peter B.

1981-01-01

A high energy XeBr laser for producing coherent radiation at 282 nm. The XeBr laser utilizes an electric discharge as the excitation source to minimize formation of molecular ions thereby minimizing absorption of laser radiation by the active medium. Additionally, HBr is used as the halogen donor which undergoes harpooning reactions with Xe.sub.M * to form XeBr*.

High-energy diffraction microscopy at the advanced photon source

DEFF Research Database (Denmark)

Lienert, U.; Li, S. F.; Hefferan, C. M.

2011-01-01

The status of the High Energy Diffraction Microscopy (HEDM) program at the 1-ID beam line of the Advanced Photon Source is reported. HEDM applies high energy synchrotron radiation for the grain and sub-grain scale structural and mechanical characterization of polycrystalline bulk materials in situ...

Generation of intense X-radiation and high-energy-density matter by laser-accelerated electrons; Erzeugung von intensiver Roentgenstrahlung und Materie hoher Energiedichte durch Laserbeschleunigte Elektronen

Energy Technology Data Exchange (ETDEWEB)

Schoenlein, Andreas

2015-07-01

Aim of this thesis was to study the processes of the interaction between highly intense short-pulse laser and matter. The focus lied thereby on the generation of intense X-radiation and warm dense matter. The studies performed for this thesis comprehend thereby the influence of laser parameters like energy, pulse length, focus size, and intensity as well as the influence of the target geometry on the interaction and generation of high-energy-density matter. In this thesis for this two selected experiments are presented. First a silver foil was used as target, in order to study the generation of radiation at 21 keV. Both bremsstrahlung and characteristic X-radiation were used in order to characterize the interaction. For the second experiment freely standing titanium wires were used as target. Hereby the focus lied on the characterization of the heated matter.

Generation of 1.3 μm and 1.5 μm high-energy Raman radiations in α-BaTeMo2O9 crystals

Science.gov (United States)

Liu, Shande; Zhang, Junjie; Gao, Zeliang; Wei, Lei; Zhang, Shaojun; He, Jingliang; Tao, Xutang

2014-02-01

The generations of high energy 2nd- and 3rd-order stimulated Raman scattering lasers based on the α-BaTeMo2O9 crystal were demonstrated for the first time. The Raman gain coefficient has been compared with that of the YVO4 crystal. A maximum total Stokes radiation energy of 27.3 mJ was obtained, containing 20.1 mJ 2nd-order Stokes energy at 1318 nm, together with 7.2 mJ 3rd-order Stokes energy at 1497 nm, giving an overall conversion efficiency of 35.9% and a slope efficiency of 54.5%. With an optical coating design, a total 3rd- and 4th-order Stokes energy of 16.5 mJ was generated. The maximum energy for 4th-order Stokes radiation at 1731 nm was 2 mJ. The pulse durations for the 2nd-, 3rd-, and 4th-order Stokes shift were 10 ns, 8.6 ns, and 5.2 ns, respectively. Our experimental results show that the α-BTM crystal is a promising Raman crystal for the generations of eye-safe radiations.

Evaluation of high-energy electron detectors for probing the inner magnetosphere under high-counting condition

International Nuclear Information System (INIS)

Tamada, Yukihiro; Takashima, Takeshi; Mitani, Takefumi; Miyake, Wataru

2013-01-01

An ERG (Energization and Radiation in Geospace) satellite will be launched to study the acceleration processes of energetic particles in the radiation belt surrounding the earth. It is very important to reveal the acceleration process of high-energy particles for both science and the application to space weather forecast. Drastic increases of high-energy electrons in the radiation belt is sometimes observed during a geomagnetic storm. When a large magnetic storm occurs, energetic electron count rates may exceed flux limits expected in the nominal design and large number of incident electrons leading to detection loss. The purpose of this study is to demonstrate that the count rate range of a single detection on board ERG satellite can be expanded by means of reading circuit operations to decrease an area of detection. In our ground experiment, we also found an unexpected result that count peaks shift to the higher energy side under high counting conditions. (author)

Influence of semiclassical plasma on the energy levels and radiative transitions in highly charged ions★

Science.gov (United States)

Hu, Hong-Wei; Chen, Zhan-Bin; Chen, Wen-Cong; Liu, Xiao-Bin; Fu, Nian; Wang, Kai

2017-11-01

Considering the quantum effects of diffraction and the collective screening effects, the potential of test charge in semiclassical plasmas is derived. It is generalized exponential screened Coulomb potential. Using the Ritz variational method incorporating this potential, the effects of semiclassical plasma on the energy levels and radiative transitions are investigated systematically, taking highly charged H-like ion as an example. The Debye plasma model is also employed for comparison purposes. Comparisons and analysis are made between these two sets of results and the differences are discussed. Contribution to the Topical Issue "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, Grzegorz Karwasz.

Present state and problems of radiological protection monitoring for high energy electron accelerator facilities in SPring-8

International Nuclear Information System (INIS)

Miyamoto, Yukihiro; Harada, Yasunori; Ueda, Hisao

1998-09-01

The present state and problems of the radiological protection monitoring for the high-energy electron accelerator are summarized. In the radiological protection monitoring for SPring-8, a third generation synchrotron radiation facility, there are many problems specific to the high-energy electron accelerator. This report describes the monitoring technique of pulsed radiation, high-energy radiation and low-energy radiation, and their problems. The management of induced radioactivity and the effects of electro-magnetic noise to monitoring instruments are also discussed. (author)

Radiation energy calibrating system and method

International Nuclear Information System (INIS)

Jacobson, A.F.

1980-01-01

A radiation energy calibrating system and method which uses a pair of calibrated detectors for measurements of radiation intensity from x-ray tubes for a non-invasive determination of the electrical characteristics; I.E., the tube potential and/or current

High power beam profile monitor with optical transition radiation

International Nuclear Information System (INIS)

Denard, J.C.; Piot, P.; Capek, K.; Feldl, E.

1997-01-01

A simple monitor has been built to measure the profile of the high power beam (800 kW) delivered by the CEBAF accelerator at Jefferson Lab. The monitor uses the optical part of the forward transition radiation emitted from a thin carbon foil. The small beam size to be measured, about 100 μm, is challenging not only for the power density involved but also for the resolution the instrument must achieve. An important part of the beam instrumentation community believes the radiation being emitted into a cone of characteristic angle 1/γ is originated from a region of transverse dimension roughly λγ; thus the apparent size of the source of transition radiation would become very large for highly relativistic particles. This monitor measures 100 μm beam sizes that are much smaller than the 3.2 mm λγ limit; it confirms the statement of Rule and Fiorito that optical transition radiation can be used to image small beams at high energy. The present paper describes the instrument and its performance. The authors tested the foil in, up to 180 μA of CW beam without causing noticeable beam loss, even at 800 MeV, the lowest CEBAF energy

High-energy chemical processes: Laser irradiation of aromatic hydrocarbons

International Nuclear Information System (INIS)

Trifunac, A.D.; Liu, A.D.; Loffredo, D.M.

1994-01-01

Recent studies of the high-energy photochemical degradation of polycyclic aromatic hydrocarbons (PAHs) in solution have furthered our fundamental understanding of the way in which radiation interacts with matter. A new comprehensive mechanism that unifies many of the seemingly contradictory observations in radiation and photochemistry has been proposed on basis of evidence gathered using specialized techniques such as transient optical spectroscopy and transient dc conductivity. The PAH molecules were activated by two-photon ionization, and behavior of the transient ions were monitored as a function of photon energy. It was found that a greater percentage of ions retain sufficient energy to decompose when higher energy light was used. When these cations decompose they leave a trail of products that establish a ''high-energy'' decomposition pathway that involves proton transfer from the ion, a mechanism hitherto not considered in photoionization processes

Polymers under ionizing radiation: the study of energy transfers to radiation induced defects

International Nuclear Information System (INIS)

Ventura, A.

2013-01-01

Radiation-induced defects created in polymers submitted to ionizing radiations, under inert atmosphere, present the same trend as a function of the dose. When the absorbed dose increases, their concentrations increase then level off. This behavior can be assigned to energy transfers from the polymer to the previously created macromolecular defects; the latter acting as energy sinks. During this thesis, we aimed to specify the influence of a given defect, namely the trans-vinylene, in the behavior of polyethylene under ionizing radiations. For this purpose, we proposed a new methodology based on the specific insertion, at various concentrations, of trans-vinylene groups in the polyethylene backbone through chemical synthesis. This enables to get rid of the variety of created defects on one hand and on the simultaneity of their creation on the other hand. Modified polyethylenes, containing solely trans-vinylene as odd groups, were irradiated under inert atmosphere, using either low LET beams (gamma, beta) or high LET beams (swift heavy ions). During irradiations, both macromolecular defects and H 2 emission were quantified. According to experimental results, among all defects, the influence of the trans-vinylene on the behavior of polyethylene is predominant. (author) [fr

Microsystem for remote sensing of high energy radiation with associated extremely low photon flux densities

Science.gov (United States)

Otten, A.; Jain, V. K.

2015-08-01

This paper presents a microsystem for remote sensing of high energy radiation in extremely low flux density conditions. With wide deployment in mind, potential applications range from nuclear non-proliferation, to hospital radiation-safety. The daunting challenge is the low level of photon flux densities - emerging from a Scintillation Crystal (SC) on to a ~1 mm-square detector, which are a factor of 10000 or so lower than those acceptable to recently reported photonic chips (including `single-photon detection' chips), due to a combination of low Lux, small detector size, and short duration SC output pulses - on the order of 1 μs. These challenges are attempted to be overcome by the design of an innovative `System on a Chip' type microchip, with high detector sensitivity, and effective coupling from the SC to the photodetector. The microchip houses a tiny n+ diff p-epi photodiode (PD) as well as the associated analog amplification and other related circuitry, all fabricated in 0.5micron, 3-metal 2-poly CMOS technology. The amplification, together with pulse-shaping of the photocurrent-induced voltage signal, is achieved through a tandem of two capacitively coupled, double-cascode amplifiers. Included in the paper are theoretical estimates and experimental results.

Nuclear energy and health: and the benefits of low-dose radiation hormesis.

Science.gov (United States)

Cuttler, Jerry M; Pollycove, Myron

2009-01-01

Energy needs worldwide are expected to increase for the foreseeable future, but fuel supplies are limited. Nuclear reactors could supply much of the energy demand in a safe, sustainable manner were it not for fear of potential releases of radioactivity. Such releases would likely deliver a low dose or dose rate of radiation, within the range of naturally occurring radiation, to which life is already accustomed. The key areas of concern are discussed. Studies of actual health effects, especially thyroid cancers, following exposures are assessed. Radiation hormesis is explained, pointing out that beneficial effects are expected following a low dose or dose rate because protective responses against stresses are stimulated. The notions that no amount of radiation is small enough to be harmless and that a nuclear accident could kill hundreds of thousands are challenged in light of experience: more than a century with radiation and six decades with reactors. If nuclear energy is to play a significant role in meeting future needs, regulatory authorities must examine the scientific evidence and communicate the real health effects of nuclear radiation. Negative images and implications of health risks derived by unscientific extrapolations of harmful effects of high doses must be dispelled.

Mitigated FPGA design of multi-gigabit transceivers for application in high radiation environments of High Energy Physics experiments

International Nuclear Information System (INIS)

Brusati, M.; Camplani, A.; Cannon, M.; Chen, H.; Citterio, M.

2017-01-01

SRAM-ba8ed Field Programmable Gate Array (FPGA) logic devices arc very attractive in applications where high data throughput is needed, such as the latest generation of High Energy Physics (HEP) experiments. FPGAs have been rarely used in such experiments because of their sensitivity to radiation. The present paper proposes a mitigation approach applied to commercial FPGA devices to meet the reliability requirements for the front-end electronics of the Liquid Argon (LAr) electromagnetic calorimeter of the ATLAS experiment, located at CERN. Particular attention will be devoted to define a proper mitigation scheme of the multi-gigabit transceivers embedded in the FPGA, which is a critical part of the LAr data acquisition chain. A demonstrator board is being developed to validate the proposed methodology. :!\\litigation techniques such as Triple Modular Redundancy (T:t\\IR) and scrubbing will be used to increase the robustness of the design and to maximize the fault tolerance from Single-Event Upsets (SEUs).

Energy spectra variations of high energy electrons in magnetic storms observed by ARASE and HIMAWARI

Science.gov (United States)

Takashima, T.; Higashio, N.; Mitani, T.; Nagatsuma, T.; Yoshizumi, M.

2017-12-01

The ARASE spacecraft was launched in December 20, 2016 to investigate mechanisms for acceleration and loss of relativistic electrons in the radiation belts during space storms. The six particle instruments with wide energy range (a few eV to 10MeV) are onboard the ARASE spacecraft. Especially, two particle instruments, HEP and XEP observe high energy electron with energy range from 70keV to over 10Mev. Those instruments observed several geomagnetic storms caused by coronal hole high speed streams or coronal mass ejections from March in 2017. The relativistic electrons in the outer radiation belt were disappeared/increased and their energy spectra were changed dynamically in some storms observed by XEP/HEP onboard the ARASE spacecraft. In the same time, SEDA-e with energy range 200keV-4.5MeV for electron on board the HIMAWARI-8, Japanese weather satellite on GEO, observed increase of relativistic electron in different local time. We will report on energy spectra variations of high energy electrons including calibrations of differential flux between XEP and HEP and discuss comparisons with energy spectra between ARAE and HIMAWARI that observed each storm in different local time.

Radiation protection challenges in the management of radioactive waste from high-energy accelerators.

Science.gov (United States)

Ulrici, Luisa; Algoet, Yvon; Bruno, Luca; Magistris, Matteo

2015-04-01

The European Laboratory for Particle Physics (CERN) has operated high-energy accelerators for fundamental physics research for nearly 60 y. The side-product of this activity is the radioactive waste, which is mainly generated as a result of preventive and corrective maintenance, upgrading activities and the dismantling of experiments or accelerator facilities. Prior to treatment and disposal, it is common practice to temporarily store radioactive waste on CERN's premises and it is a legal requirement that these storage facilities are safe and secure. Waste treatment typically includes sorting, segregation, volume and size reduction and packaging, which will depend on the type of component, its chemical composition, residual activity and possible surface contamination. At CERN, these activities are performed in a dedicated waste treatment centre under the supervision of the Radiation Protection Group. This paper gives an overview of the radiation protection challenges in the conception of a temporary storage and treatment centre for radioactive waste in an accelerator facility, based on the experience gained at CERN. The CERN approach consists of the classification of waste items into 'families' with similar radiological and physical-chemical properties. This classification allows the use of specific, family-dependent techniques for radiological characterisation and treatment, which are simultaneously efficient and compliant with best practices in radiation protection. The storage was planned on the basis of radiological and other possible hazards such as toxicity, pollution and fire load. Examples are given of technical choices for the treatment and radiological characterisation of selected waste families, which could be of interest to other accelerator facilities. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

High thermal efficiency, radiation-based advanced fusion reactors. Final report

International Nuclear Information System (INIS)

Taussig, R.T.

1977-04-01

A new energy conversion scheme is explored in this study which has the potential of achieving thermal cycle efficiencies high enough (e.g., 60 to 70 percent) to make advanced fuel fusion reactors attractive net power producers. In this scheme, a radiation boiler admits a large fraction of the x-ray energy from the fusion plasma through a low-Z first wall into a high-Z working fluid where the energy is absorbed at temperatures of 2000 0 K to 3000 0 K. The hot working fluid expands in an energy exchanger against a cooler, light gas, transferring most of the work of expansion from one gas to the other. By operating the radiation/boiler/energy exchanger as a combined cycle, full advantage of the high temperatures can be taken to achieve high thermal efficiency. The existence of a mature combined cycle technology from the development of space power plants gives the advanced fuel fusion reactor application a firm engineering base from which it can grow rapidly, if need be. What is more important, the energy exchanger essentially removes the peak temperature limitations previously set by heat engine inlet conditions, so that much higher combined cycle efficiencies can be reached. This scheme is applied to the case of an advanced fuel proton-boron 11 fusion reactor using a single reheat topping and bottoming cycle. A wide variety of possible working fluid combinations are considered and particular cycle calculations for the thermal efficiency are presented. The operation of the radiation boiler and energy exchanger are both described. Material compatibility, x-ray absorption, thermal hydraulics, structural integrity, and other technical features of these components are analyzed to make a preliminary assessment of the feasibility of this concept

Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos

NARCIS (Netherlands)

Ando, S.; Baret, B.; Bartos, I.; Bouhou, B.; Chassande-Mottin, E.; Corsi, A.; Di Palma, I.; Dietz, A.; Donzaud, C.; Eichler, D.; Finley, C.; Guetta, D.; Halzen, F.; Jones, G.; Kandhasamy, S.; Kotake, K.; Kouchner, A.; Mandic, V.; Márka, S.; Márka, Z.; Moscoso, L.; Papa, M.A.; Piran, T.; Pradier, T.; Romero, G.E.; Sutton, P.; Thrane, E.; van Elewyck, V.; Waxman, E.

2013-01-01

Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic

Solar Energy Education. Renewable energy activities for junior high/middle school science

Energy Technology Data Exchange (ETDEWEB)

1985-01-01

Some basic topics on the subject of solar energy are outlined in the form of a teaching manual. The manual is geared toward junior high or middle school science students. Topics include solar collectors, solar water heating, solar radiation, insulation, heat storage, and desalination. Instructions for the construction of apparatus to demonstrate the solar energy topics are provided. (BCS)

High-energy synchrotron radiation x-ray microscopy: Present status and future prospects

International Nuclear Information System (INIS)

Jones, K.W.; Gordon, B.M.; Spanne, P.; Rivers, M.L.; Sutton, S.R.

1991-01-01

High-energy radiation synchrotron x-ray microscopy is used to characterize materials of importance to the chemical and materials sciences and chemical engineering. The x-ray microscope (XRM) forms images of elemental distributions fluorescent x rays or images of mass distributions by measurement of the linear attenuation coefficient of the material. Distributions of sections through materials are obtained non-destructively using the technique of computed microtomography. The energy range of the x rays used for the XRM ranges from a few keV at the minimum value to more than 100 keV, which is sufficient to excite the K-edge of all naturally occurring elements. The work in progress at the Brookhaven NSLS X26 and X17 XRM is described in order to show the current status of the XRM. While there are many possible approaches to the XRM instrumentation, this instrument gives state-of-the-art performance in most respects and serves as a reasonable example of the present status of the instrumentation in terms of the spatial resolution and minimum detection limits obtainable. The examples of applications cited give an idea of the types of research fields that are currently under investigation. They can be used to illustrate how the field of x-ray microscopy will benefit from the use of bending magnets and insertion devices at the Advanced Photon Source. 8 refs., 5 figs

High-energy synchrotron radiation x-ray microscopy: Present status and future prospects

International Nuclear Information System (INIS)

Jones, K.W.; Gordon, B.M.; Spanne, P.; Rivers, M.L.; Sutton, S.R.

1991-01-01

High-energy radiation synchrotron x-ray microscopy is used to characterize materials of importance to the chemical and materials sciences and chemical engineering. The x-ray microscope (XRM) forms images of elemental distributions fluorescent x rays or images of mass distributions by measurement of the linear attenuation coefficient of the material. Distributions of sections through materials are obtained non-destructively using the technique of computed microtomography (CMT). The energy range of the x rays used for the XRM ranges from a few keV at the minimum value to more than 100 keV, which is sufficient to excite the K-edge of all naturally occurring elements. The work in progress at the Brookhaven NSLS X26 and X17 XRM is described in order to show the current status of the XRM. While there are many possible approaches to the XRM instrumentation, this instrument gives state-of-the-art performance in most respects and serves as a reasonable example of the present status of the instrumentation in terms of the spatial resolution and minimum detection limits (MDLs) obtainable. The examples of applications cited give an idea of the types of research fields that are currently under investigation. They can be used to illustrate how the field of x-ray microscopy will benefit from the use of bending magnets and insertion devices at the Advanced Photon Source (APS)

A comparison of the microbicidal effectiveness of gamma rays and high and low energy electron radiations

International Nuclear Information System (INIS)

Tallentire, Alan; Miller, Arne; Helt-Hansen, Jakob

2010-01-01

The radiation response of spores of Bacillus pumilus were examined for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV. The responses were found to be the same for all types of radiation within the measurement uncertainties and were also in agreement with a previously published value.

A comparison of the microbicidal effectiveness of gamma rays and high and low energy electron radiations

DEFF Research Database (Denmark)

Tallentire, A.; Miller, Arne; Helt-Hansen, Jakob

2010-01-01

The radiation response of spores of Bacillus pumilus were examined for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV. The responses were found to be the same for all types of radiation within the measurement uncertainties and were also in agreement...... with a previously published value....

Preparation of plastic-cellulose compounds by high energy gamma radiation

International Nuclear Information System (INIS)

Rosa, M.C.F.

1978-01-01

The use of high intensity sources of ionizing radiation for inducing polymer cross-linking was studied and the feasibility of its application in making plastic and cellulose combined compounds, particularly plates formed by paper sheets aglutinated with polyester resin, was analyzed. Several types of paper capable of being used in the plate composition were tested. It was verified that with the preparation technique used in this work the ordinary filter paper gave the best results. By different material testing techniques it was found that the chemical and mechanical properties of plates cured with radiation doses of about 1.5 Mrad are favorably compared with those exhibited by plates of equal composition, cured by the classic method (adding chemical initiator and accelerator) [pt

Intercomparison of radiation protection devices in a high-energy stray neutron field, Part II: Bonner sphere spectrometry

International Nuclear Information System (INIS)

Wiegel, B.; Agosteo, S.; Bedogni, R.; Caresana, M.; Esposito, A.; Fehrenbacher, G.; Ferrarini, M.; Hohmann, E.; Hranitzky, C.; Kasper, A.; Khurana, S.; Mares, V.; Reginatto, M.; Rollet, S.; Ruehm, W.; Schardt, D.; Silari, M.; Simmer, G.; Weitzenegger, E.

2009-01-01

The European Commission has funded within its 6th Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. A major task of the CONRAD Work Package 'complex mixed radiation fields at workplaces' was to organise a benchmark exercise in a workplace field at a high-energy particle accelerator where neutrons are the dominant radiation component. The CONRAD benchmark exercise took place at the Gesellschaft fuer Schwerionenforschung mbH (GSI) in Darmstadt, Germany in July 2006. In this paper, the results of the spectrometry using four extended -range Bonner sphere spectrometers of four different institutes are reported. Outside Cave A the neutron spectra were measured with three spectrometers at six selected positions and ambient dose equivalent values were derived for use in the intercomparison with other area monitors and dosemeters. At a common position all three spectrometers were used to allow a direct comparison of their results which acts as an internal quality assurance. The comparison of the neutron spectra measured by the different groups shows very good agreement. A detailed analysis presents some differences between the shapes of the spectra and possible sources of these differences are discussed. However, the ability of Bonner sphere spectrometers to provide reliable integral quantities like fluence and ambient dose equivalent is well demonstrated in this exercise. The fluence and dose results derived by the three groups agree very well within the given uncertainties, not only with respect to the total energy region present in this environment but also for selected energy regions which contribute in certain strength to the total values. In addition to the positions outside Cave A one spectrometer was used to measure the neutron spectrum at one position in the entry maze of Cave A. In this case a comparison was possible to earlier measurements.

Energy and particle transport in the radiative divertor plasmas of DIII-D

International Nuclear Information System (INIS)

Leonard, A.W.; Allen, S.L.; Brooks, N.H.

1997-06-01

It has been argued that divertor energy transport dominated by parallel electron thermal conduction, or q parallel = -kT 5/2 2 dT e /ds parallel, leads to severe localization of the intense radiating region and ultimately limits the fraction of energy flux that can be radiated before striking the divertor target. This is due to the strong T 5/2 e dependence of electron heat conduction which results in very short spatial scales of the T e gradient at high power densities and low temperatures where deuterium and impurities radiate most effectively. However, we have greatly exceeded this constraint on DIII-D with deuterium gas puffing which reduces the peak heat flux to the divertor plate a factor of 5 while distributing the divertor radiation over a long length

High energy photon emission from wakefields

Energy Technology Data Exchange (ETDEWEB)

Farinella, D. M., E-mail: dfarinel@uci.edu; Lau, C. K.; Taimourzadeh, S.; Hwang, Y.; Abazajian, K.; Canac, N.; Taborek, P.; Tajima, T. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Zhang, X. M., E-mail: zhxm@siom.ac.cn [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Koga, J. K., E-mail: koga.james@qst.go.jp [Kansai Photon Science Institute, Japan Atomic Energy Agency (JAEA), Kizugawa, Kyoto 619-0215 (Japan); Ebisuzaki, T., E-mail: ebisu@riken.jp [RIKEN, Wako, Saitama 351-0198 (Japan)

2016-07-15

Experimental evidence has accumulated to indicate that wakefield acceleration (WFA) accompanies intense and sometimes coherent emission of radiation such as from betatron radiation. The investigation of this issue has additional impetus nowadays because we are learning (1) there is an additional acceleration process of the ponderomotive acceleration; (2) WFA may become relevant in much higher density regimes; (3) WFA has been proposed as the mechanism for extreme high energy cosmic ray acceleration and gamma ray bursts for active galactic nuclei. These require us to closely examine the radiative mechanisms in WFA anew. We report studies of radiation from wakefield (self-injected betatron) and ponderomotive (laser field) mechanisms in scalings of the frequency and intensity of the driver, as well as the plasma density.

Review of relative biological effectiveness dependence on linear energy transfer for low-LET radiations

International Nuclear Information System (INIS)

Hunter, Nezahat; Muirhead, Colin R

2009-01-01

Information on Japanese A-bomb survivors exposed to gamma radiation has been used to estimate cancer risks for the whole range of photon (x-rays) and electron energies which are commonly encountered by radiation workers in the work place or by patients and workers in diagnostic radiology. However, there is some uncertainty regarding the radiation effectiveness of various low-linear energy transfer (low-LET) radiations (x-rays, gamma radiation and electrons). In this paper we review information on the effectiveness of low-LET radiations on the basis of epidemiological and in vitro radiobiological studies. Data from various experimental studies for chromosome aberrations and cell transformation in human lymphocytes and from epidemiological studies of the Japanese A-bomb survivors, patients medically exposed to radiation for diagnostic and therapeutic procedures, and occupational exposures of nuclear workers are considered. On the basis of in vitro cellular radiobiology, there is considerable evidence that the relative biological effectiveness (RBE) of high-energy low-LET radiation (gamma radiation, electrons) is less than that of low-energy low-LET radiation (x-rays, betas). This is a factor of about 3 to 4 for 29 kVp x-rays (e.g. as in diagnostic radiation exposures of the female breast) and for tritium beta-rays (encountered in parts of the nuclear industry) relative to Co-60 gamma radiation and 2-5 MeV gamma-rays (as received by the Japanese A-bomb survivors). In epidemiological studies, although for thyroid and breast cancer there appears to be a small tendency for the excess relative risks to decrease as the radiation energy increases for low-LET radiations, it is not statistically feasible to draw any conclusion regarding an underlying dependence of cancer risk on LET for the nominally low-LET radiations. (review)

Experimental study of the efficiency of transformation of the dense plasma hypersonic flow kinetic energy into a radiation

International Nuclear Information System (INIS)

Kamrukov, A.S.; Kozlov, N.P.; Myshelov, E.P.; Protasov, Yu.S.

1981-01-01

Analysis of physical specific features of radiator where plasma heating is performed with tbermalization of directed kinetic energy of dense plasma flows accelerated electrodynamically up to hypersonic velocities during its shock deceleration, is given. It is shown that the plasma heating method considered has a number of principle advantages as compared with methods most disseminated now for generation of dense intensively radiating plasma (current heating exploding method) and suggests new possibilities for construction of selective high brightness radiat.ion sources of ultraviolet and far vacuum ultraviolet ranges of spectrum. Radiation gas dynamic processes of hypersonic plasma flow deceleration formed with magnetoplasma compressors have been experimentally investigated on their interaction with condenced matters in vacuum and basic thermodynamic parameters of shock compressed plasma have been determined. It is shown that the conversion process of kinetic energy of high-velocity plasma flows to radiation is accomplished at very high efficiency-integral luminescence of shock compressed plasma can reach approximately 90% of initial kinetic energy of flow [ru

Analysis of Proton Radiation Effects on Gallium Nitride High Electron Mobility Transistors

Science.gov (United States)

2017-03-01

non - ionizing proton radiation damage effects at different energy levels on a GaN-on-silicon high electron mobility transistor...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) In this work, a physics-based simulation of non - ionizing proton radiation damage effects at different...Polarization . . . . . . . . . . . . . . 6 2.3 Non - Ionizing Radiation Damage Effects . . . . . . . . . . . . . . . 10 2.4 Non - Ionizing Radiation Damage in

Gamma radiation effects on the rheological properties of high and low density polyethylenes

International Nuclear Information System (INIS)

Rangel-Nafaile, C.; Garcia-Rejon, A.; Garcia Leon, A.

1986-01-01

High energy radiation of polymeric materials is a topic of considerable interest from commercial and scientific points of view. Within an inert atmosphere, irradiation of polyethylene yields a crosslinking effect with a consequent improvement in its mechanical properties in comparison to the virgin materials. Additionally, if irradiated specimens are melted and recrystallized, the radiation-induced crosslinking hinders their crystalline growth altering dramatically their flow properties such as the elasticity. This work portrays the effects of the gamma radiation on the rheological properties of high and low density polyethylenes manufactured by PEMEX and analyzes the implications of theoretical results derived from the Acierno's model when it is implemented with the rheological properties of high energy irradiated polyethylenes. (author)

Computational methods for high-energy source shielding

International Nuclear Information System (INIS)

Armstrong, T.W.; Cloth, P.; Filges, D.

1983-01-01

The computational methods for high-energy radiation transport related to shielding of the SNQ-spallation source are outlined. The basic approach is to couple radiation-transport computer codes which use Monte Carlo methods and discrete ordinates methods. A code system is suggested that incorporates state-of-the-art radiation-transport techniques. The stepwise verification of that system is briefly summarized. The complexity of the resulting code system suggests a more straightforward code specially tailored for thick shield calculations. A short guide line to future development of such a Monte Carlo code is given

Development of Nuclear Energy and Radiation Textbooks for Elementary School Students

International Nuclear Information System (INIS)

Han, E.; Choi, Y.; Yang, J.; Lee, S.

2015-01-01

The textbooks for elementary school students were developed to help future generations make value judgments based on appropriate information about nuclear energy and radiation. The themes and educational contents of the 13 lessons, to be delivered in one semester at elementary school level, were selected by the educational requirements of students, science teachers, and experts. The “Radiation and Life” textbook for elementary school students consists of the following chapters: – Chapter 1. What is nuclear energy and radiation?, – Chapter 2. Who discovered the nuclear energy and radiation?, – Chapter 3. Why is nuclear energy and radiation important?, – Chapter 4. Is nuclear energy and radiation dangerous?, – Chapter 5. Let’s learn about what to do when an accident occurs, – Chapter 6. How are nuclear energy and radiation used?, – Chapter 7. What is nuclear power generation?, – Chapter 8. Why is radiation used for food?, – Chapter 9. What is medical radiation?, – Chapter 10. What kind of irradiated products are in our daily lives?, – Chapter 11. What jobs are related to nuclear energy and radiation?, – Chapter 12. What are energies of future?, – Chapter 13. Concept of Talk-talk (a study review game). The general trend in recent educational curriculum development suppresses national education course organizations and authorities and expands the autonomy and authority of regions and schools. The derived textbook contents are expected to be helpful as first textbooks for the autonomous selection of education about nuclear energy and radiation for use in creative experiences developed at the school level. (author)

High-brightness electron beams for production of high intensity, coherent radiation for scientific and industrial applications

International Nuclear Information System (INIS)

Kim, K.-J.

1999-01-01

Relativistic electron beams with high six-dimensional phase space densities, i.e., high-brightness beams, are the basis for efficient generation of intense and coherent radiation beams for advanced scientific and industrial applications. The remarkable progress in synchrotrons radiation facilities from the first generation to the current, third-generation capability illustrates this point. With the recent development of the high-brightness electron gun based on laser-driven rf photocathodes, linacs have become another important option for high-brightness electron beams. With linacs of about 100 MeV, megawatt-class infrared free-electron lasers can be designed for industrial applications such as power beaming. With linacs of about 10 GeV, 1- angstrom x-ray beams with brightness and time resolution exceeding by several orders of magnitude the current synchrotrons radiation sources can be generated based on self-amplified spontaneous emission. Scattering of a high-brightness electron beam by high power laser beams is emerging as a compact method of generating short-pulse, bright x-rays. In the high-energy frontier, photons of TeV quantum energy could be generated by scattering laser beams with TeV electron beams in future linear colliders

High-energy radiation and polymers: A review of commercial processes and emerging applications

International Nuclear Information System (INIS)

Clough, R.L.

2001-01-01

Ionizing radiation has been found to be widely applicable in modifying the structure and properties of polymers, and can be used to tailor the performance of either bulk materials or surfaces. Fifty years of research in polymer radiation chemistry has led to numerous applications of commercial and economic importance, and work remains active in the application of radiation to practical uses involving polymeric materials. This paper provides a survey of radiation-processing methods of industrial interest, ranging from technologies already commercially well established, through innovations in the active R and D stage which show exceptional promise for future commercial use. Radiation-processing technologies are discussed under the following categories: cross-linking of plastics and rubbers, curing of coatings and inks, heat-shrink products, fiber-matrix composites, chain-scission for processing control, surface modification, grafting, hydrogels, sterilization, natural product enhancement, plastics recycling, ceramic precursors, electronic property materials, ion-track membranes and lithography for microdevice production. In addition to new technological innovations utilizing conventional gamma and e-beam sources, a number of promising new applications make use of novel radiation types which include ion beams (heavy ions, light ions, highly focused microscopic beams and high-intensity pulses), soft X-rays which are focused, coherent X-rays (from a synchrotron) and e-beams which undergo scattering to generate patterns

Radiation Detection and Dual-Energy X-Ray Imaging for Port Security

Energy Technology Data Exchange (ETDEWEB)

Pashby, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glenn, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Divin, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martz, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-08-09

Millions of cargo containers are transported across the United States border annually and are inspected for illicit radioactive material and contraband using a combination of passive radiation portal monitors (RPM) and high energy X-ray non-intrusive inspection (NII) systems. As detection performance is expected to vary with the material composition of cargo, characterizing the types of material present in cargo is important to national security. This work analyzes the passive radiation and dual energy radiography signatures from on RPM and two NII system, respectively. First, the cargos were analyzed to determine their ability to attenuate emissions from an embedded radioactive source. Secondly, dual-energy X-ray discrimination was used to determine the material composition and density of the cargos.

Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation

OpenAIRE

Schroeder, Jeremy; Thomson, W.; Howard, B.; Schell, N.; Näslund, Lars-Åke; Rogström, Lina; Johansson-Jöesaar, Mats P.; Ghafoor, Naureen; Odén, Magnus; Nothnagel, E.; Shepard, A.; Greer, J.; Birch, Jens

2015-01-01

We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (greater than50 keV), high photon flux (greater than10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (less than1 s) two-dimensional (2D) detector, permits time-resolved in situ structural analysis of thin film formation...

Cosmic very high-energy {gamma}-rays

Energy Technology Data Exchange (ETDEWEB)

Plaga, R. [Max-Planck-Institut fur Physik, Muenchen (Germany)

1998-12-31

The article gives a brief overview, aimed at nonspecialists, about the goals and selected recent results of the detection of very-high energy {gamma}-rays (energies above 100 GeV) with ground based detectors. The stress is on the physics questions, specially the origin of Galactic Cosmic Rays and the emission of TeV {gamma}-radiation from active galaxies. Moreover some particle-physics questions which are addressed in this area are discussed.

Dose characteristics of high-energy electrons, muons and photons

International Nuclear Information System (INIS)

Britvich, G.I.; Krupnyj, G.I.; Peleshko, V.N.; Rastsvetalov, Ya.N.

1980-01-01

Differential distribution of energy release at different depth of tissue-equivalent phantoms (plexiglas, polystyrene, polyethylene) at the energy of incident electrons, muons of 0.2-40 GeV and photons with the mean energy of 3.6 GeV are measured. The error of experimental results does not exceed 7%. On the basis of the data obtained dose characteristics of electrons, muons and photons for standard geometry are estimated. For all types of irradiation the maximum value of specific equivalent dose, nremxcm 2 /part. is presented. It is shown that published values of specific equivalent dose of electron radiation are higher in all the investigated energy range from 0.2 to 40 GeV, and for muon radiation a good agreement with the present experiment is observed. The highly precise results obtained which cover the wide dynamic range according to the energy of incident particles can serve as the basis for reconsidering the existing recommendations for dose characteristics of electron radiation [ru

Gene-expression profiling of Saccharomyces cerevisiae irradiated by high-LET radiations

Data.gov (United States)

National Aeronautics and Space Administration — Ionizing radiations are categorized by linear energy transfer (LET) into low-LET and high-LET. High-LET is considered to have a higher relative biological...

Secondary radiation dose during high-energy total body irradiation

Energy Technology Data Exchange (ETDEWEB)

Janiszewska, M.; Raczkowski, M. [Lower Silesian Oncology Center, Medical Physics Department, Wroclaw (Poland); Polaczek-Grelik, K. [University of Silesia, Medical Physics Department, Katowice (Poland); Szafron, B.; Konefal, A.; Zipper, W. [University of Silesia, Department of Nuclear Physics and Its Applications, Katowice (Poland)

2014-05-15

The goal of this work was to assess the additional dose from secondary neutrons and γ-rays generated during total body irradiation (TBI) using a medical linac X-ray beam. Nuclear reactions that occur in the accelerator construction during emission of high-energy beams in teleradiotherapy are the source of secondary radiation. Induced activity is dependent on the half-lives of the generated radionuclides, whereas neutron flux accompanies the treatment process only. The TBI procedure using a 18 MV beam (Clinac 2100) was considered. Lateral and anterior-posterior/posterior-anterior fractions were investigated during delivery of 2 Gy of therapeutic dose. Neutron and photon flux densities were measured using neutron activation analysis (NAA) and semiconductor spectrometry. The secondary dose was estimated applying the fluence-to-dose conversion coefficients. The main contribution to the secondary dose is associated with fast neutrons. The main sources of γ-radiation are the following: {sup 56}Mn in the stainless steel and {sup 187}W of the collimation system as well as positron emitters, activated via (n,γ) and (γ,n) processes, respectively. In addition to 12 Gy of therapeutic dose, the patient could receive 57.43 mSv in the studied conditions, including 4.63 μSv from activated radionuclides. Neutron dose is mainly influenced by the time of beam emission. However, it is moderated by long source-surface distances (SSD) and application of plexiglass plates covering the patient body during treatment. Secondary radiation gives the whole body a dose, which should be taken into consideration especially when one fraction of irradiation does not cover the whole body at once. (orig.) [German] Die zusaetzliche Dosis durch sekundaere Neutronen- und γ-Strahlung waehrend der Ganzkoerperbestrahlung mit Roentgenstrahlung aus medizinischen Linearbeschleunigern wurde abgeschaetzt. Bei der Emission hochenergetischer Strahlen zur Teletherapie finden hauptsaechlich im Beschleuniger

Single-field isodose charts for high-energy radiation

International Nuclear Information System (INIS)

1962-01-01

The main part of this guide comprises isodose chart specifications divided into four sections: cesium-137 gamma rays, cobalt-60 gamma rays, high-energy x-rays and electron beams. In each section the information is further classified according to the equipment model and the institution of origin. 1 fig

Manual on high energy teletherapy. Incorporating: Applications guide, procedures guide, basics guide

International Nuclear Information System (INIS)

1992-01-01

Apart from a basic guide to the principles of the production of ionizing radiation and to methods of radiation protection and dose measurements, this booklet contains information about radiation protection measures for high-energy teletherapy

Characterization and performance optimization of radiation monitoring sensors for high energy physics experiments at the CERN LHC and Super-LHC

CERN Document Server

Mekki, Julien

2009-01-01

In order to study the matter originating from the universe, a new particle accelerator named the Large Hadron Collider (LHC) has been built at CERN. The radiation environment generated by the hadrons collisions in the high energy physics experiments of the LHC will be complex and locally very intense. For monitoring this complex radiation field, dosimeters have been installed in the LHC experiments. In previous study, RadFET dosimeters and PIN diodes have been characterized for their use in the particle accelerator. However, even if the RadFETs sensors have been already extensively characterized, their radiation response can be affected by their package. Depending on the material and the geometry, the package can induce errors in the dose measurement. In this thesis, a complete study has been carried out in order to evaluate its influence. Concerning the PIN diodes, the readout protocol used for the LHC is no longer valuable for the Super-LHC. Therefore, a complete study on their radiation response has been p...

Low energy current accumulator for high-energy proton rings

International Nuclear Information System (INIS)

Month, M.

1977-01-01

Building current in high-energy p-p colliding beam machines is most appropriately done in a low-energy (small circumference) current accumulator. Three significant factors favor such a procedure: First, large rings tend to be susceptible to unstable longitudinal density oscillations. These can be avoided by pumping up the beam in the accumulator. When the current stack is injected into the storage ring, potentially harmful instability is essentially neutralized. Second, high-field magnets characteristic of future high energy proton rings are designed with superconducting coils within the iron magnetic shield. This means coil construction and placement errors propagate rapidly within the beam aperture. An intermediate ''stacking ring'' allows the minimum use of the superconducting ring aperture. Finally, the coils are vulnerable to radiation heating and possible magnet quenching. By minimizing beam manipulaion in the superconducting environment and using only the central portion of the beam aperture, coil vulnerability can be put at a minimum

Nuclear energy and radiation protection law: no. 14 1987

International Nuclear Information System (INIS)

1987-01-01

The full text of Jordan's Nuclear Energy and Radiation Protection Law, no. 14 1987. The law's 39 articles govern all aspects organizing the utilization of nuclear energy and radiation protection activities in the country; including terms and conditions for licensing activities and personnel, and the import, export, and disposal of radioactive sources. The law establishes for the purpose of implementing its regulations, a consultative technical committee and a radiation protection board, both in the Ministry of Energy and Mineral Resources

Tolerance of the High Energy X-ray Imaging Technology ASIC to potentially destructive radiation processes in Earth-orbit-equivalent environments

Science.gov (United States)

Ryan, D. F.; Baumgartner, W. H.; Wilson, M.; Benmoussa, A.; Campola, M.; Christe, S. D.; Gissot, S.; Jones, L.; Newport, J.; Prydderch, M.; Richards, S.; Seller, P.; Shih, A. Y.; Thomas, S.

2018-02-01

The High Energy X-ray Imaging Technology (HEXITEC) ASIC is designed on a 0.35 μm CMOS process to read out CdTe or CZT detectors and hence provide fine-pixellated spectroscopic imaging in the range 2-200 keV. In this paper, we examine the tolerance of HEXITEC to both potentially destructive cumulative and single event radiation effects. Bare ASICs are irradiated with X-rays up to a total ionising dose (TID) of 1 Mrad (SiO2) and bombarded with heavy ions with linear energy transfer (LET) up to 88.3 MeV mg-1 cm-2. HEXITEC is shown to operate reliably below a TID of 150 krad, have immunity to fatal single event latchup (SEL) and have high tolerance to non-fatal SEL up to LETs of at least 88.3 MeV mg-1 cm-2. The results are compared to predictions of TID and SELs for various Earth-orbits and aluminium shielding thicknesses. It is found that HEXITEC's radiation tolerance to both potentially destructive cumulative and single event effects is sufficient to reliably operate in these environments with moderate shielding.

High-temperature partition functions, specific heats and spectral radiative properties of diatomic molecules with an improved calculation of energy levels

Science.gov (United States)

Qin, Z.; Zhao, J. M.; Liu, L. H.

2018-05-01

The level energies of diatomic molecules calculated by the frequently used Dunham expansion will become less accurate for high-lying vibrational and rotational levels. In this paper, the potential curves for the lower-lying electronic states with accurate spectroscopic constants are reconstructed using the Rydberg-Klein-Rees (RKR) method, which are extrapolated to the dissociation limits by fitting of the theoretical potentials, and the rest of the potential curves are obtained from the ab-initio results in the literature. Solving the rotational dependence of the radial Schrödinger equation over the obtained potential curves, we determine the rovibrational level energies, which are then used to calculate the equilibrium and non-equilibrium thermodynamic properties of N2, N2+, NO, O2, CN, C2, CO and CO+. The partition functions and the specific heats are systematically validated by available data in the literature. Finally, we calculate the radiative source strengths of diatomic molecules in thermodynamic equilibrium, which agree well with the available values in the literature. The spectral radiative intensities for some diatomic molecules in thermodynamic non-equilibrium are calculated and validated by available experimental data.

Research on high energy density plasmas and applications

International Nuclear Information System (INIS)

1999-01-01

Recently, technologies on lasers, accelerators, and pulse power machines have been significantly advanced and input power density covers the intensity range from 10 10 W/cm 2 to higher than 10 20 W/cm 2 . As the results, high pressure gas and solid targets can be heated up to very high temperature to create hot dense plasmas which have never appeared on the earth. The high energy density plasmas opened up new research fields such as inertial confinement fusion, high brightness X-ray radiation sources, interiors of galactic nucleus,supernova, stars and planets, ultra high pressure condensed matter physics, plasma particle accelerator, X-ray laser, and so on. Furthermore, since these fields are intimately connected with various industrial sciences and technologies, the high energy density plasma is now studied in industries, government institutions, and so on. This special issue of the Journal of Plasma Physics and Nuclear Fusion Research reviews the high energy density plasma science for the comprehensive understanding of such new fields. In May, 1998, the review committee for investigating the present status and the future prospects of high energy density plasma science was established in the Japan Society of Plasma Science and Nuclear Fusion Research. We held three committee meetings to discuss present status and critical issues of research items related to high energy density plasmas. This special issue summarizes the understandings of the committee. This special issue consists of four chapters: They are Chapter 1: Physics important in the high energy density plasmas, Chapter 2: Technologies related to the plasma generation; drivers such as lasers, pulse power machines, particle beams and fabrication of various targets, Chapter 3: Plasma diagnostics important in high energy density plasma experiments, Chapter 4: A variety of applications of high energy density plasmas; X-ray radiation, particle acceleration, inertial confinement fusion, laboratory astrophysics

Calculation and Measurement of Low-Energy Radiative Moller Scattering

Science.gov (United States)

Epstein, Charles; DarkLight Collaboration

2017-09-01

A number of current nuclear physics experiments have come to rely on precise knowledge of electron-electron (Moller) and positron-electron (Bhabha) scattering. Some of these experiments, having lepton beams on targets containing atomic electrons, use these purely-QED processes as normalization. In other scenarios, with electron beams at low energy and very high intensity, Moller scattering and radiative Moller scattering have such enormous cross-sections that the backgrounds they produce must be understood. In this low-energy regime, the electron mass is also not negligible in the calculation of the cross section. This is important, for example, in the DarkLight experiment (100 MeV). As a result, we have developed a new event generator for the radiative Moller and Bhabha processes, with new calculations that keep all terms of the electron mass. The MIT High Voltage Research Laboratory provides us a unique opportunity to study this process experimentally and compare it with our work, at a low beam energy of 2.5 MeV where the effects of the electron mass are significant. We are preparing a dedicated apparatus consisting of a magnetic spectrometer in order to directly measure this process. An overview of the calculation and the status of the experiment will be presented.

Device for imaging an object by means of masks of spatially modulable electromagnetic radiation or corpuscular radiation of high energy

International Nuclear Information System (INIS)

Barrett, H.H.

1979-01-01

The radiogram of the thyroid is produced by means of a detector device operating similar to a scintillation camera. Between thyroid and detector device there is placed a mask having modulating areas, permeable and impermeable to radiation succeeding each other with decreasing extension. The scanning signal has got the shape of a radar signal with chirp modulation. The filtering unit used for it is a pulse compression filter. The image of the radiation energy distribution on the recording surface of the detector device is thus decoded and compressed to a number of image points giving the picture of the thyroid. (RW) [de

The problems associated with the monitoring of complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

Czech Academy of Sciences Publication Activity Database

Bilski, P.; Blomgren, J.; d´Errico, F.; Esposito, A.; Fehrenbacher, G.; Fernández, F.; Fuchs, A.; Golnik, N.; Lacoste, V.; Leuschner, A.; Sandri, S.; Silari, M.; Spurný, František; Wiegel, B.; Wright, P.

2007-01-01

Roč. 126, 1-4 (2007), s. 491-496 ISSN 0144-8420 R&D Projects: GA MŠk 1P05OC032 Grant - others:ES(XE) Contract no FI6R-012684 Institutional research plan: CEZ:AV0Z10480505 Keywords : radiation fields * european high-energy accelerators * thermonuclear fusion facilities Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.528, year: 2007

Studies in theorectical high energy particles physics

International Nuclear Information System (INIS)

Aratyn, H.; Keung, Wai-Yee; Panigrahi, P.; Sukhatme, U.

1990-02-01

This paper discusses the research being done at the University of Illinois in theoretical high energy physics. Some areas discussed are string models, collider physics, symmetries in gauge theories, sigma model, radiative decay of mesons, supersymmetry, superconducting, and hydroproduction of charm

Perspectives on High-Energy-Density Physics

Science.gov (United States)

Drake, R. Paul

2008-11-01

Much of 21st century plasma physics will involve work to produce, understand, control, and exploit very non-traditional plasmas. High-energy density (HED) plasmas are often examples, variously involving strong Coulomb interactions and few particles per Debeye sphere, dominant radiation effects, strongly relativistic effects, or strongly quantum-mechanical behavior. Indeed, these and other modern plasma systems often fall outside the early standard theoretical definitions of ``plasma''. This presentation will focus on two types of HED plasmas that exhibit non-traditional behavior. Our first example will be the plasmas produced by extremely strong shock waves. Shock waves are present across the entire realm of plasma densities, often in space or astrophysical contexts. HED shock waves (at pressures > 1 Mbar) enable studies in many areas, from equations of state to hydrodynamics to radiation hydrodynamics. We will specifically consider strongly radiative shocks, in which the radiative energy fluxes are comparable to the mechanical energy fluxes that drive the shocks. Modern HED facilities can produce such shocks, which are also present in dense, energetic, astrophysical systems such as supernovae. These shocks are also excellent targets for advanced simulations due to their range of spatial scales and complex radiation transport. Our second example will be relativistic plasmas. In general, these vary from plasmas containing relativistic particle beams, produced for some decades in the laboratory, to the relativistic thermal plasmas present for example in pulsar winds. Laboratory HED relativistic plasmas to date have been those produced by laser beams of irradiance ˜ 10^18 to 10^22 W/cm^2 or by accelerator-produced HED electron beams. These have applications ranging from generation of intense x-rays to production of proton beams for radiation therapy to acceleration of electrons. Here we will focus on electron acceleration, a spectacular recent success and a rare

Why heavy and light quarks radiate energy with similar rates

International Nuclear Information System (INIS)

Kopeliovich, B. Z.; Potashnikova, I. K.; Schmidt, Ivan

2010-01-01

The dead-cone effect has been predicted to reduce the magnitude of energy loss and jet quenching for heavy flavors produced with large p T in heavy-ion collisions. On the contrary, data from the Relativistic Heavy Ion Collider demonstrate a strong suppression of high-p T electrons from charm and bottom decays. We show that vacuum radiation of a highly virtual quark produced at high p T with a stripped-off color field develops a much wider dead cone, which screens the one related to the quark mass. Lacking the field, gluons cannot be radiated within this cone until the color field is regenerated and the quark virtuality cools down to the scale of the order of the quark mass. However, this takes longer than is essential for the observed jet quenching, leading to similar nuclear effects for the light and charm quark jets. Open beauty is expected to radiate much less within the p T range studied so far in heavy-ion collisions.

High energy physics and cosmology

International Nuclear Information System (INIS)

Silk, J.I.

1991-01-01

This research will focus on the implications of recent theories and experiments in high energy physics of the evolution of the early universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including studies of the nature of dark matter and the signature of annihilations in the galactic halo, where the resulting γ-ray fluxes are potentially observable, and in stars, where stellar evolution may be affects. We will develop constraints on the inflationary predictions of scale-free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon, examining the observable imprint of primordial density fluctuations on the cosmic microwave background radiation in both flat and curved cosmological models, and implications for observations of large-scale galaxy clustering and structure formation theories. We will also study spectral distortions in the microwave background radiation that are produced by exotic particle decays in the very early universe. We expect such astrophysical considerations to provide fruitful insights both into high-energy particle physics and into possible cosmological for the early universe

PASOTRON high-energy microwave source

Science.gov (United States)

Goebel, Dan M.; Schumacher, Robert W.; Butler, Jennifer M.; Hyman, Jay, Jr.; Santoru, Joseph; Watkins, Ron M.; Harvey, Robin J.; Dolezal, Franklin A.; Eisenhart, Robert L.; Schneider, Authur J.

1992-04-01

A unique, high-energy microwave source, called PASOTRON (Plasma-Assisted Slow-wave Oscillator), has been developed. The PASOTRON utilizes a long-pulse E-gun and plasma- filled slow-wave structure (SWS) to produce high-energy pulses from a simple, lightweight device that utilizes no externally produced magnetic fields. Long pulses are obtained from a novel E-gun that employs a low-pressure glow discharge to provide a stable, high current- density electron source. The electron accelerator consists of a high-perveance, multi-aperture array. The E-beam is operated in the ion-focused regime where the plasma filling the SWS space-charge neutralizes the beam, and the self-pinch force compresses the beamlets and increases the beam current density. A scale-model PASOTRON, operating as a backward- wave oscillator in C-band with a 100-kV E-beam, has produced output powers in the 3 to 5 MW range and pulse lengths of over 100 microsecond(s) ec, corresponding to an integrated energy per pulse of up to 500 J. The E-beam to microwave-radiation power conversion efficiency is about 20%.

Overview. Department of High Energy Physics. Section 5

International Nuclear Information System (INIS)

Coghen, T.

1995-01-01

The activities of Department of High Energy Physics in 1994 have been presented. They cover a variety of problems of experimental and theoretical high energy elementary particle physics: hadronic and leptonic interactions with nucleons and nuclei (mainly characteristics of particle production , including heavy quark physics), e + e - interactions and tests of the Standard Model (also evaluations of radiative corrections), ultrarelativistic heavy ion interactions and search for the quark-gluon plasma, as well as spectra, composition and interactions of high energy cosmic ray particles.Research on detectors and development of apparatus for high energy physics experiments at future accelerators such as LHC or RHIC were also carried out. The short information about personnel employed in the Department, seminars, publication, conferences and reports is also given

Overview. Department of High Energy Physics. Section 5

Energy Technology Data Exchange (ETDEWEB)

Coghen, T. [Institute of Nuclear Physics, Cracow (Poland)

1995-12-31

The activities of Department of High Energy Physics in 1994 have been presented. They cover a variety of problems of experimental and theoretical high energy elementary particle physics: hadronic and leptonic interactions with nucleons and nuclei (mainly characteristics of particle production , including heavy quark physics), e{sup +} e{sup -} interactions and tests of the Standard Model (also evaluations of radiative corrections), ultrarelativistic heavy ion interactions and search for the quark-gluon plasma, as well as spectra, composition and interactions of high energy cosmic ray particles.Research on detectors and development of apparatus for high energy physics experiments at future accelerators such as LHC or RHIC were also carried out. The short information about personnel employed in the Department, seminars, publication, conferences and reports is also given.

Overview. Department of High Energy Physics. Section 5

Energy Technology Data Exchange (ETDEWEB)

Coghen, T [Institute of Nuclear Physics, Cracow (Poland)

1996-12-31

The activities of Department of High Energy Physics in 1994 have been presented. They cover a variety of problems of experimental and theoretical high energy elementary particle physics: hadronic and leptonic interactions with nucleons and nuclei (mainly characteristics of particle production , including heavy quark physics), e{sup +} e{sup -} interactions and tests of the Standard Model (also evaluations of radiative corrections), ultrarelativistic heavy ion interactions and search for the quark-gluon plasma, as well as spectra, composition and interactions of high energy cosmic ray particles.Research on detectors and development of apparatus for high energy physics experiments at future accelerators such as LHC or RHIC were also carried out. The short information about personnel employed in the Department, seminars, publication, conferences and reports is also given.

Dose conversion coefficients for high-energy photons, electrons, neutrons and protons

CERN Document Server

Sakamoto, Y; Sato, O; Tanaka, S I; Tsuda, S; Yamaguchi, Y; Yoshizawa, N

2003-01-01

In the International Commission on Radiological Protection (ICRP) 1990 Recommendations, radiation weighting factors were introduced in the place of quality factors, the tissue weighting factors were revised, and effective doses and equivalent doses of each tissues and organs were defined as the protection quantities. Dose conversion coefficients for photons, electrons and neutrons based on new ICRP recommendations were cited in the ICRP Publication 74, but the energy ranges of theses data were limited and there are no data for high energy radiations produced in accelerator facilities. For the purpose of designing the high intensity proton accelerator facilities at JAERI, the dose evaluation code system of high energy radiations based on the HERMES code was developed and the dose conversion coefficients of effective dose were evaluated for photons, neutrons and protons up to 10 GeV, and electrons up to 100 GeV. The dose conversion coefficients of effective dose equivalent were also evaluated using quality fact...

Status report of the Cornell High Energy Synchrotron Radiation Source (CHESS)

International Nuclear Information System (INIS)

Batterman, B.W.

1980-01-01

The Wilson Laboratory at Cornell University has done pioneering work on the development of high energy synchrotrons. In the last decade the 12 GeV Wilson Synchrotron was the most energetic electron synchrotron in the world. In 1975 plans were formulated at the Wilson Laboratory to build a new electron-positron storage ring to cover the range from 4-8 GeV. The storage ring was to be constructed in the same tunnel as the present synchrotron and to use the latter as an injector for the ring. A novel injection feature was to be incorporated, namely, vernier phase compression. In this scheme, positron coalesence is to be performed by compressing a 30-60 bunch positron beam by tranferring individual bunches from the storage ring to the synchrotron and stacking back into the storage ring. This procedure takes advantage of the slight circumferential difference between the storage ring and the synchrotron. Positron beams of 10 mA have been achieved in CESR at the present time. The first colliding beam studies were performed in an October 1979 two-week running period at which time CHESS, the synchrotron radiation source associated with CESR, also had its first extended experience with synchrotron light. (orig.)

Neutron dose measurements with the GSI ball at high energy accelerators

International Nuclear Information System (INIS)

Fehrenbacher, G.; Gutermuth, F.; Radon, T.; Kozlova, E.

2005-01-01

Full text: At high energy particle accelerators the production of neutron radiation dominates radiation protection. For the radiation survey at accelerators there is a need for reliable detection systems (passive radiation monitors), which can measure the dose for a wide range of neutron energies independently on the beam pulse structure of the produced radiation. In this work a passive neutron dosemeter for the measurement of the ambient dose equivalent is presented. The dosemeter is suitable for measurements of the emerging neutron radiation at accelerators for the whole energy range up to about 10 GeV. The dosemeter consists of a polyethylene sphere, TL elements (pairs of TLD600/700) and an additional lead layer (PE/Pb) in neutron fields at high energy accelerators is investigated in this work. Results of dose measurements which were performed in realistic neutron fields at the high energy accelerator SPS at CERN (CERF facility) and in Cave A at the heavy ion synchrotron SIS at GSI are presented. The results of these measurements are compared with the expected dose values from the neutron spectra determined for the measurement positions at CERF and in Cave A (FLUKA) and with the dosemeter response derived by the calculated response functions (FLUKA) folded with the neutron spectra. The comparisons show that the additional lead layer in the PE/Pb-sphere improves significantly the response of the dosemeter. The response of the PE/Pb-sphere is 40 to 50 % higher at CERF and Cave A in comparison to the bare PE-sphere. At CERF the dose values of the PE/Pb-sphere is about 25 % lower than the expected dose value, whilst for Cave A, a rather good agreement was found (2 % deviation). (author)

Energy dependence of an ionization chamber with parallel plates in standard gamma and x-radiation fields

International Nuclear Information System (INIS)

Batistella, M.A.; Caldas, L.V.E.

1988-09-01

The characteristics of low energy X-radiation standard fields were determined and the energy dependence of a ionization chamber of the superficial type, with parallel plates and fixed volume, normally utilized in the dosimetry at the Radiotherapy level was studied. The possibility of adaptation of this chamber type for use in gamma radiation dosimetry was verified. Different thickness Lucite build-up caps, from 2.0 up to 5.5 mm, were produced and tested in 60 Co and 137 Cs gamma radiation fields. This type of detector, with the adequate build-up cap, presented a performance comparable to that of the thimble type ionization chamber. It was concluded that it is not necessary to use different kinds of chambers for each high and mean energy interval. The superficial chamber, specially produced to detect low energy X-radiation, may be adapted to detect gamma radiation. (author) [pt

Measurement of leakage and design for the protective barrier of the high energy radiation therapy room

International Nuclear Information System (INIS)

Chu, S.S.; Park, C.Y.

1981-01-01

The logical development of an optimum structural shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV are presented. We obtained following results by comparison in between the precalculating values and actual survey after complete installation of radiogenerating units. 1) The calculating formula for the protective barrier written in NCRP report no. 34(1970) was the most ideal and economic calculating methods for the construction of barrier and to determine thickness for the meeting requirements of the number of patients of 80-100 in daily treatment. 2) The precalculating values of protective barrier are 5 times more protective than that of actual measurement. It is depending on radiation workload and utilization the data most securely. 3) The dose rate during exposure are 2-10 mR/hr at out of the door and the control room. 4) The foul smelling and ozone gas production from long exposure of cancer patients cannot be estimated when the room is ill ventilated. (author)

High-energy astrophysics and the search for sources of gravitational waves

Science.gov (United States)

O'Brien, P. T.; Evans, P.

2018-05-01

The dawn of the gravitational-wave (GW) era has sparked a greatly renewed interest into possible links between sources of high-energy radiation and GWs. The most luminous high-energy sources-gamma-ray bursts (GRBs)-have long been considered as very likely sources of GWs, particularly from short-duration GRBs, which are thought to originate from the merger of two compact objects such as binary neutron stars and a neutron star-black hole binary. In this paper, we discuss: (i) the high-energy emission from short-duration GRBs; (ii) what other sources of high-energy radiation may be observed from binary mergers; and (iii) how searches for high-energy electromagnetic counterparts to GW events are performed with current space facilities. While current high-energy facilities, such as Swift and Fermi, play a crucial role in the search for electromagnetic counterparts, new space missions will greatly enhance our capabilities for joint observations. We discuss why such facilities, which incorporate new technology that enables very wide-field X-ray imaging, are required if we are to truly exploit the multi-messenger era. This article is part of a discussion meeting issue `The promises of gravitational-wave astronomy'.

High-frequency energy in singing and speech

Science.gov (United States)

Monson, Brian Bruce

While human speech and the human voice generate acoustical energy up to (and beyond) 20 kHz, the energy above approximately 5 kHz has been largely neglected. Evidence is accruing that this high-frequency energy contains perceptual information relevant to speech and voice, including percepts of quality, localization, and intelligibility. The present research was an initial step in the long-range goal of characterizing high-frequency energy in singing voice and speech, with particular regard for its perceptual role and its potential for modification during voice and speech production. In this study, a database of high-fidelity recordings of talkers was created and used for a broad acoustical analysis and general characterization of high-frequency energy, as well as specific characterization of phoneme category, voice and speech intensity level, and mode of production (speech versus singing) by high-frequency energy content. Directionality of radiation of high-frequency energy from the mouth was also examined. The recordings were used for perceptual experiments wherein listeners were asked to discriminate between speech and voice samples that differed only in high-frequency energy content. Listeners were also subjected to gender discrimination tasks, mode-of-production discrimination tasks, and transcription tasks with samples of speech and singing that contained only high-frequency content. The combination of these experiments has revealed that (1) human listeners are able to detect very subtle level changes in high-frequency energy, and (2) human listeners are able to extract significant perceptual information from high-frequency energy.

Coherent radiation from high-current electron beams of linear accelerators and its applications

International Nuclear Information System (INIS)

Okuda, Shuichi; Takanaka, Makoto; Nakamura, Mitsumi; Kato, Ryukou; Takahashi, Toshiharu; Nam, Soon-Kwon; Taniguchi, Ryouichi; Kojima, Takao

2006-01-01

The characteristics of the far-infrared light source using the coherent radiation emitted from a high-energy short electron bunch have been investigated. The coherent radiation has a continuous spectrum in a submillimeter to millimeter wavelength range and the brightness is relatively high. The spectrum of the radiation is determined by the longitudinal form factor of the electron bunch. The operational conditions of a high-current linear accelerator have been optimized using an electron bunch shape monitor. The coherent transition radiation light source has been applied to absorption spectroscopy for liquid water and to an imaging experiment for a leaf of rose

Problems in the development of high-energy radiation processing of woven and knitted fabrics

International Nuclear Information System (INIS)

Ihme, B.; Maeder, E.; Mally, S.

1983-01-01

The modification of hygienic properties of garments made of polyamide and polyester planar structures has been investigated. The results underline the fact that radiation-induced modification aimed at increasing the serviceability of textile planar structures is a relatively complicated process of textile finishing resulting in the need of additional chemicals, facilities, manpower, and energy. (author)

Influence of high energy electrons on ECRH in LHD

Directory of Open Access Journals (Sweden)

Ogasawara S.

2012-09-01

Full Text Available The central bulk electron temperature of more than 20 keV is achieved in LHD as a result of increasing the injection power and the lowering the electron density near 2 × 1018 m−3. Such collision-less regime is important from the aspect of the neoclassical transport and also the potential structure formation. The presences of appreciable amount of high energy electrons are indicated from hard X-ray PHA, and the discrepancy between the stored energy and kinetic energy estimated from Thomson scattering. ECE spectrum are also sensitive to the presence of high energy electrons and discussed by solving the radiation transfer equation. The ECRH power absorption to the bulk and the high energy electrons are dramatically affected by the acceleration and the confinement of high energy electrons. The heating mechanisms and the acceleration process of high energy electrons are discussed by comparing the experimental results and the ray tracing calculation under assumed various density and mean energy of high energy electrons.

Design concept of radiation control system for the high intensity proton accelerator facility

Energy Technology Data Exchange (ETDEWEB)

Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori; Harada, Yasunori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2002-11-01

Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics. (author)

A mixed analog-digital radiation hard technology for high energy physics electronics DMILL (Durci Mixte sur Isolant Logico-Linéaire)

CERN Document Server

Beuville, E; Borgeaud, P; Fourches, N T; Rouger, M; Blanc, J P; Bruel, M; Delevoye-Orsier, E; Gautier, J; Du Port de Pontcharra, J; Truche, R; Dupont-Nivet, E; Flament, O; Leray, J L; Martin, J L; Montaron, J; Borel, G; Brice, J M; Chatagnon, P; Terrier, C; Aubert, Jean-Jacques; Delpierre, P A; Habrard, M C; Potheau, R; CERN. Geneva. Detector Research and Development Committee

1992-01-01

The high radiation level expected in the inner regions of the high luminosity LHC detectors (gamma and neutron) will require radiation hardened electronics. A consortium between the CEA (Commissariat a l'Energie Atomique) and Thomson TMS (Thomson Composants Militaires et Spatiaux) has been created to push for the development and the industrialization of a nascent technology which looks particularly adapted to the needs of HEP electronics. This technology, currently under development at the LETI(CEA), uses a SIMOX substrate with an epitaxial silicon film. It includes CMOS, JFETs and vertical bipolar transistors with a potential multi-megarad hardness. The CMOS and bipolar transistors constitute a rad-hard BiCMOS which will be useful to design analog and digital high-speed architectures. JFETs, which have intrinsically high hardness behaviour and low noise performances even at low temperature will enable very rad-hard, low noise front end electronics to be designed. Present results, together with the improvemen...

Soft errors in 10-nm-scale magnetic tunnel junctions exposed to high-energy heavy-ion radiation

Science.gov (United States)

Kobayashi, Daisuke; Hirose, Kazuyuki; Makino, Takahiro; Onoda, Shinobu; Ohshima, Takeshi; Ikeda, Shoji; Sato, Hideo; Inocencio Enobio, Eli Christopher; Endoh, Tetsuo; Ohno, Hideo

2017-08-01

The influences of various types of high-energy heavy-ion radiation on 10-nm-scale CoFeB-MgO magnetic tunnel junctions with a perpendicular easy axis have been investigated. In addition to possible latent damage, which has already been pointed out in previous studies, high-energy heavy-ion bombardments demonstrated that the magnetic tunnel junctions may exhibit clear flips between their high- and low-resistance states designed for a digital bit 1 or 0. It was also demonstrated that flipped magnetic tunnel junctions still may provide proper memory functions such as read, write, and hold capabilities. These two findings proved that high-energy heavy ions can produce recoverable bit flips in magnetic tunnel junctions, i.e., soft errors. Data analyses suggested that the resistance flips stem from magnetization reversals of the ferromagnetic layers and that each of them is caused by a single strike of heavy ions. It was concurrently found that an ion strike does not always result in a flip, suggesting a stochastic process behind the flip. Experimental data also showed that the flip phenomenon is dependent on the device and heavy-ion characteristics. Among them, the diameter of the device and the linear energy transfer of the heavy ions were revealed as the key parameters. From their dependences, the physical mechanism behind the flip was discussed. It is likely that a 10-nm-scale ferromagnetic disk loses its magnetization due to a local temperature increase induced by a single strike of heavy ions; this demagnetization is followed by a cooling period associated with a possible stochastic recovery process. On the basis of this hypothesis, a simple analytical model was developed, and it was found that the model accounts for the results reasonably well. This model also predicted that magnetic tunnel junctions provide sufficiently high soft-error reliability for use in space, highlighting their advantage over their counterpart conventional semiconductor memories.

Mechanism of cluster DNA damage repair in response to high-atomic number and energy particles radiation

Energy Technology Data Exchange (ETDEWEB)

Asaithamby, Aroumougame, E-mail: Aroumougame.Asaithamy@UTsouthwestern.edu [Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390 (United States); Chen, David J., E-mail: David.Chen@UTsouthwestern.edu [Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390 (United States)

2011-06-03

Low-linear energy transfer (LET) radiation (i.e., {gamma}- and X-rays) induces DNA double-strand breaks (DSBs) that are rapidly repaired (rejoined). In contrast, DNA damage induced by the dense ionizing track of high-atomic number and energy (HZE) particles is slowly repaired or is irreparable. These unrepaired and/or misrepaired DNA lesions may contribute to the observed higher relative biological effectiveness for cell killing, chromosomal aberrations, mutagenesis, and carcinogenesis in HZE particle irradiated cells compared to those treated with low-LET radiation. The types of DNA lesions induced by HZE particles have been characterized in vitro and usually consist of two or more closely spaced strand breaks, abasic sites, or oxidized bases on opposing strands. It is unclear why these lesions are difficult to repair. In this review, we highlight the potential of a new technology allowing direct visualization of different types of DNA lesions in human cells and document the emerging significance of live-cell imaging for elucidation of the spatio-temporal characterization of complex DNA damage. We focus on the recent insights into the molecular pathways that participate in the repair of HZE particle-induced DSBs. We also discuss recent advances in our understanding of how different end-processing nucleases aid in repair of DSBs with complicated ends generated by HZE particles. Understanding the mechanism underlying the repair of DNA damage induced by HZE particles will have important implications for estimating the risks to human health associated with HZE particle exposure.

Mechanism of cluster DNA damage repair in response to high-atomic number and energy particles radiation

International Nuclear Information System (INIS)

Asaithamby, Aroumougame; Chen, David J.

2011-01-01

Low-linear energy transfer (LET) radiation (i.e., γ- and X-rays) induces DNA double-strand breaks (DSBs) that are rapidly repaired (rejoined). In contrast, DNA damage induced by the dense ionizing track of high-atomic number and energy (HZE) particles is slowly repaired or is irreparable. These unrepaired and/or misrepaired DNA lesions may contribute to the observed higher relative biological effectiveness for cell killing, chromosomal aberrations, mutagenesis, and carcinogenesis in HZE particle irradiated cells compared to those treated with low-LET radiation. The types of DNA lesions induced by HZE particles have been characterized in vitro and usually consist of two or more closely spaced strand breaks, abasic sites, or oxidized bases on opposing strands. It is unclear why these lesions are difficult to repair. In this review, we highlight the potential of a new technology allowing direct visualization of different types of DNA lesions in human cells and document the emerging significance of live-cell imaging for elucidation of the spatio-temporal characterization of complex DNA damage. We focus on the recent insights into the molecular pathways that participate in the repair of HZE particle-induced DSBs. We also discuss recent advances in our understanding of how different end-processing nucleases aid in repair of DSBs with complicated ends generated by HZE particles. Understanding the mechanism underlying the repair of DNA damage induced by HZE particles will have important implications for estimating the risks to human health associated with HZE particle exposure.

Radiation-damage studies, irradiations and high-dose dosimetry for LHC detectors

CERN Document Server

Coninckx, F; León-Florián, E; Leutz, H; Schönbacher, Helmut; Sonderegger, P; Tavlet, Marc; Sopko, B; Henschel, H; Schmidt, H U; Boden, A; Bräunig, D; Wulf, F; Cramariuc, R; Ilie, D; Fattibene, P; Onori, S; Miljanic, S; Paic, G; Razen, B; Razem, D; Rendic, D; CERN. Geneva. Detector Research and Development Committee

1991-01-01

The proposal is divided into a main project and special projects. The main project consists of a service similar to the one given in the past to accelerator construction projects at CERN (ISR,SPS,LEP) on high-dose dosimetry, material irradiations, irradiations tests, standardization of test procedures and data compilations. Large experience in this field and numerous radiation damage test data of insulating and structural materials are available. The special projects cover three topics which are of specific interest for LHC detector physicists and engineers at CERN and in other high energy physics institutes, namely: Radiation effects in scintillators; Selection of radiation hard optical fibres for data transmission; and Selection and testing of radiation hard electronic components.

CHESS-the Cornell High Energy Synchrotron Source

International Nuclear Information System (INIS)

Batterman, B.W.; Cornell Univ., Ithaca, NY

1980-01-01

The Wilson Laboratory at Cornell University has done pioneering work on development of high energy synchrotrons. In the last decade, the 12 GeV synchrotron has been the most energetic electron synchrotron in the world. In 1975 plans were formulated to build a 4-8 GeV storage ring in the same tunnel as the synchrotron and to use the latter as the injector for the storage ring. This small radius (the normal bend magnets have R = 87 m), coupled with the relatively high electron energy of the storage ring, makes these magnets potent sources of synchrotron radiation. In June of 1978 the National Science Foundation funded a project to create CHESS, the Cornell High Energy Synchrotron Source. (orig./FKS)

Silicon detectors for x and gamma-ray with high radiation resistance

International Nuclear Information System (INIS)

Cimpoca, Valerica; Popescu, Ion V.; Ruscu, Radu

2001-01-01

Silicon detectors are widely used in X and gamma-ray spectroscopy for direct detection or coupled with scintillators in high energy nuclear physics (modern collider experiments are representative), medicine and industrial applications. In X and gamma dosimetry, a low detection limit (under 6 KeV) with silicon detectors becomes available. Work at the room temperature is now possible due to the silicon processing evolution, which assures low reverse current and high life time of carriers. For several years, modern semiconductor detectors have been the primary choice for the measurement of nuclear radiation in various scientific fields. Nowadays the recently developed high resolution silicon detectors found their way in medical applications. As a consequence many efforts have been devoted to the development of high sensitivity and radiation hardened X and gamma-ray detectors for the energy range of 5 - 150 keV. The paper presents some results concerning the technology and behaviour of X and Gamma ray silicon detectors used in physics research, industrial and medical radiography. The electrical characteristics of these detectors, their modification after exposure to radiation and the results of spectroscopic X and Gamma-ray measurements are discussed. The results indicated that the proposed detectors enables the development of reliable silicon detectors to be used in controlling the low and high radiation levels encountered in a lot of application

Novel X-ray imaging diagnostics of high energy nanosecond pulse accelerators

International Nuclear Information System (INIS)

Smith, Graham W.; Gallegos, Roque Rosauro; Hohlfelder, Robert James; Beutler, David Eric; Dudley, John; Seymour, Calvin L.G.; Bell, John D.

2004-01-01

Pioneering x-ray imaging has been undertaken on a number of AWE's and Sandia National Laboratories radiation effects x-ray simulators. These simulators typically yield a single very short (<50ns) pulse of high-energy (MeV endpoint energy bremsstrahlung) x-ray radiation with doses in the kilorad (krad(Si)) region. X-ray source targets vary in size from 2 to 25cm diameter, dependent upon the particular simulator. Electronic imaging of the source x-ray emission under dynamic conditions yields valuable information upon how the simulator is performing. The resultant images are of interest to the simulator designer who may configure new x-ray source converter targets and diode designs. The images can provide quantitative information about machine performance during radiation effects testing of components under active conditions. The effects testing program is a valuable interface for validation of high performance computer codes and models for the radiation effects community. A novel high-energy x-ray imaging spectrometer is described whereby the spectral energy (0.1 to 2.5MeV) profile may be discerned from the digitally recorded and viewable images via a pinhole/scintillator/CCD imaging system and knowledge of the filtration parameters. Unique images, analysis and a preliminary evaluation of the capability of the spectrometer are presented. Further, a novel time resolved imaging system is described that captures a sequence of high spatial resolution temporal images, with zero interframe time, in the nanosecond timeframe, of our source x-rays.

Transport analysis of high radiation and high density plasmas in the ASDEX Upgrade tokamak

Directory of Open Access Journals (Sweden)

Casali L.

2014-01-01

Full Text Available Future fusion reactors, foreseen in the “European road map” such as DEMO, will operate under more demanding conditions compared to present devices. They will require high divertor and core radiation by impurity seeding to reduce heat loads on divertor target plates. In addition, DEMO will have to work at high core densities to reach adequate fusion performance. The performance of fusion reactors depends on three essential parameters: temperature, density and energy confinement time. The latter characterizes the loss rate due to both radiation and transport processes. The DEMO foreseen scenarios described above were not investigated so far, but are now addressed at the ASDEX Upgrade tokamak. In this work we present the transport analysis of such scenarios. Plasma with high radiation by impurity seeding: transport analysis taking into account the radiation distribution shows no change in transport during impurity seeding. The observed confinement improvement is an effect of higher pedestal temperatures which extend to the core via stiffness. A non coronal radiation model was developed and compared to the bolometric measurements in order to provide a reliable radiation profile for transport calculations. High density plasmas with pellets: the analysis of kinetic profiles reveals a transient phase at the start of the pellet fuelling due to a slower density build up compared to the temperature decrease. The low particle diffusion can explain the confinement behaviour.

Degradation Mechanism of Poly(Ether-Urethane) Estane Induced by High Energy Radiation (III) : Radiolytic Gases and Water Soluble Products

International Nuclear Information System (INIS)

Dannoux, A.

2006-01-01

Within the framework of nuclear waste management, there is interest in the prediction of long-term behaviour of organic materials subjected to high energy radiation. Once organic waste has been stored, gases and low molecular products might be generated from materials irradiated by radionuclides. Long-term behaviour of organic material in nuclear waste has several common concerns with radiation ageing of polymers. But a more detailed description of the chemical evolution is needed for nuclear waste management. In a first approach, an extensive work on radiation ageing is used to identify the different processes encountered during the degradation of a polyurethane, including oxidation dose rate-effects and influence of dose on the oxidation mechanism. In a second approach, a study is performed to identify and quantify gases and possible production of water soluble chemical complexing agents which might enhance radionuclides migration away from the repository. In this work, we present results concerning the production of radiolytic gases and the formation of water soluble oligomers reached with leaching tests Films were made from a poly(ether-urethane) synthesized from methylene bis(p-phenyl isocyanate) (MDI) and poly(tetramethylene glycol) (PTMG) with 1,4 butanediol (BD) and were irradiated by high-energy electron beam to cover a wide doses range and by γ rays to determine the formation/consumption yields of gases. They were measured by mass spectrometry and gas-chromatography/mass spectrometry (GC/MS). The migration of water soluble oligomers in water was reached by measuring the weight loss versus leaching time. The identification of oligomers was performed by using a mass spectrometry with an electrospray ionisation interface (ESI-MS-MS). The analysis of radiolytic gases indicates the formation of H 2 , CO 2 and CO with respective radiolytic yields of 1, 0.5 and 0.3 molecule/100 eV. The consumption of O 2 is evaluated to 6 molecules/100 eV. For absorbed doses

Dark information of black hole radiation raised by dark energy

Science.gov (United States)

Ma, Yu-Han; Chen, Jin-Fu; Sun, Chang-Pu

2018-06-01

The "lost" information of black hole through the Hawking radiation was discovered being stored in the correlation among the non-thermally radiated particles (Parikh and Wilczek, 2000 [31], Zhang et al., 2009 [16]). This correlation information, which has not yet been proved locally observable in principle, is named by dark information. In this paper, we systematically study the influences of dark energy on black hole radiation, especially on the dark information. Calculating the radiation spectrum in the existence of dark energy by the approach of canonical typicality, which is reconfirmed by the quantum tunneling method, we find that the dark energy will effectively lower the Hawking temperature, and thus makes the black hole has longer life time. It is also discovered that the non-thermal effect of the black hole radiation is enhanced by dark energy so that the dark information of the radiation is increased. Our observation shows that, besides the mechanical effect (e.g., gravitational lensing effect), the dark energy rises the stored dark information, which could be probed by a non-local coincidence measurement similar to the coincidence counting of the Hanbury-Brown-Twiss experiment in quantum optics.

High purity liquid phase epitaxial gallium arsenide nuclear radiation detector

International Nuclear Information System (INIS)

Alexiev, D.; Butcher, K.S.A.

1991-11-01

Surface barrier radiation detector made from high purity liquid phase epitaxial gallium arsenide wafers have been operated as X- and γ-ray detectors at various operating temperatures. Low energy isotopes are resolved including 241 Am at 40 deg C. and the higher gamma energies of 235 U at -80 deg C. 15 refs., 1 tab., 6 figs

Radiation energy detector and analyzer

International Nuclear Information System (INIS)

Roberts, T.G.

1981-01-01

A radiation detector array and a method for measuring the spectral content of radiation. The radiation sensor or detector is an array or stack of thin solid-electrolyte batteries. The batteries, arranged in a stack, may be composed of independent battery cells or may be arranged so that adjacent cells share a common terminal surface. This common surface is possible since the polarity of the batteries with respect to an adjacent battery is unrestricted, allowing a reduction in component parts of the assembly and reducing the overall stack length. Additionally, a test jig or chamber for allowing rapid measurement of the voltage across each battery is disclosed. A multichannel recorder and display may be used to indicate the voltage gradient change across the cells, or a small computer may be used for rapidly converting these voltage readings to a graph of radiation intensity versus wavelength or energy. The behavior of the batteries when used as a radiation detector and analyzer are such that the voltage measurements can be made at leisure after the detector array has been exposed to the radiation, and it is not necessary to make rapid measurements as is now done

Radiation defects in InN irradiated with high-energy electrons

International Nuclear Information System (INIS)

Zhivul'ko, V.D.; Mudryj, A.V.; Yakushev, M.V.; Martin, R.; Shaff, V.; Lu, Kh.; Gurskij, A.L.

2013-01-01

The influence of high energy (6 MeV, fluencies 10 15 – 10 18 cm -2 ) electron irradiation on the fundamental absorption and luminescence properties of InN thin films which were grown on sapphire substrates by molecular bean epitaxial has been studied. It is found that electron irradiation increases the electron concentration and band gap energy E g of InN. The shift of the band gap energy E g is a manifestation of the Burshtein-Mossa effect. (authors)

Theoretical and experimental study of an energy-reinforced braking radiation photon beam

International Nuclear Information System (INIS)

Bertin, Pierre-Yves

1966-01-01

This research thesis reports the theoretical study of a photon beam raised towards high energies, its experimental implementation, the definition of a gamma spectrometry method which aimed at checking various hypotheses used in the beam theoretical study. After a presentation of the theory of phenomena of electron braking radiation, of materialisation of photons into positon-negaton pair, and of issues related to multiple Coulomb diffusion, the author reports the study of the different solutions which allow a photon beam to be obtained. A braking radiation of mono-kinetic electron has been used. This braking radiation is reinforced by absorption of low energy protons in a column of lithium hydride. The author describes how the beam is built up, and the experimental approach. He describes how raw data are processed to get rid of the influence of the multiple Coulomb diffusion and of the braking radiation. Experimental results are compared with those obtained by convolution of photon spectra and differential cross section

GEM applications outside high energy physics

CERN Document Server

Duarte Pinto, Serge

2013-01-01

From its invention in 1997, the Gas Electron Multiplier has been applied in nuclear and high energy physics experiments. Over time however, other applications have also exploited the favorable properties of GEMs. The use of GEMs in these applications will be explained in principle and practice. This paper reviews applications in research, beam instrumentation and homeland security. The detectors described measure neutral radiations such as photons, x-rays, gamma rays and neutrons, as well as all kinds of charged radiation. This paper provides an overview of the still expanding range of possibilities of this versatile detector concept.

Low energy background radiation in India

International Nuclear Information System (INIS)

Gopinath, D.V.

1980-01-01

Spectral distribution of background radiation at 9 locations spread all over India has been measured. Specifications of the counting set-up standardised for measurement are given. At one of the places, the background spectrum was measured with four different types of detectors. A broad peak in 60-100 keV with differing intensity and standard deviation is observed in all the spectra. In the Kalpakkam area, the peak near the seashore is observed to be more intense than away from the shore. This could be due to the presence of monazite sands on the seashore. The natural background radiation is observed to have a steep rise below 20 keV. Peak intensity is found to be independent of both the location (i.e. the source of energy) and the type of detector used for measurement. The calculated spectra due to multiple scattered radiation (with a nominal source energy of 1 MeV) through paraffin wax and the measured background spectrum with the detector shielded with 20 cm wax show good agreement above 40 keV. This shows that 80 keV hump in the natural background radiation is a property of air. The peak, therefore, in the spectra of natural background radiation is essentially a property of medium and it is independent of location or detector. (M.G.B.)

Examining the High-energy Radiation Mechanisms of Knots and Hotspots in Active Galactic Nucleus Jets

Science.gov (United States)

Zhang, Jin; Du, Shen-shi; Guo, Sheng-Chu; Zhang, Hai-Ming; Chen, Liang; Liang, En-Wei; Zhang, Shuang-Nan

2018-05-01

We compile the radio–optical–X-ray spectral energy distributions (SEDs) of 65 knots and 29 hotspots in 41 active galactic nucleus jets to examine their high-energy radiation mechanisms. Their SEDs can be fitted with the single-zone leptonic models, except for the hotspot of Pictor A and six knots of 3C 273. The X-ray emission of 1 hotspot and 22 knots is well explained as synchrotron radiation under the equipartition condition; they usually have lower X-ray and radio luminosities than the others, which may be due to a lower beaming factor. An inverse Compton (IC) process is involved for explaining the X-ray emission of the other SEDs. Without considering the equipartition condition, their X-ray emission can be attributed to the synchrotron-self-Compton process, but the derived jet powers (P jet) are not correlated with L k and most of them are larger than L k, with more than three orders of magnitude, where L k is the jet kinetic power estimated with their radio emission. Under the equipartition condition, the X-ray emission is well interpreted with the IC process for the cosmic microwave background photons (IC/CMB). In this scenario, the derived P jet of knots and hotspots are correlated with and comparable to L k. These results suggest that the IC/CMB model may be a promising interpretation of the X-ray emission. In addition, a tentative knot–hotspot sequence in the synchrotron peak-energy–peak-luminosity plane is observed, similar to the blazar sequence, which may be attributed to the different cooling mechanisms of electrons.

Infrared radiation in the energy balance of the upper atmosphere

International Nuclear Information System (INIS)

Gordiets, B.F.; Markov, M.N.

1977-01-01

The contribution of the infrared radiation to the energy balance of the Earth's upper atmosphere is discussed. The theoretical analysis has been carried out of the mechanisms of the transformation of the energy of outgoing particles and the ultraviolet-radiation of the Sun absorbed at the heights of Z >= 90 km into the infrared radiation. It is found out the the infrared radiation within the wave length range of 1.2-20 μ is more intensive that the 63 μ radiation of atomic oxygen and plays an important role in the general energy balance and the thermal regime of the thermosphere. It has been found out too that in the area of Z >= 120 km heights the radiation in the 5.3 μ NO band is the most intensive. This radiation is to be considered for the more accurate description of parameters of the atmosphere (temperature, density) conditioning the nature of the translocation of ionospheric sounds (ISS)

Radiation effects at a high power accelerator and applications to advanced energy sources

International Nuclear Information System (INIS)

Sommer, W.F.; Garner, F.A.; Brown, R.D.; Wechsler, M.S.

1989-01-01

Many materials are exposed to atom-displacing radiation at high-power accelerators such as the Los Alamos Meson Physics Facility (LAMPF). Beam current densities in the 800-MeV proton beam vary from 12.5 mA cm -2 (8 x 10 16 p/cm 2 s) on graphite targets to 20-μA cm -2 (1.3 x 10 14 p/cm 2 s) on metal-alloy windows. High-level radiation damage results from these particle fluxes. As a consequence of secondary-particle generation in targets and windows and low-level beam losses that lead to particle interactions with structural material, various components are exposed to low-level proton fluxes, gamma radiation, and neutron fluxes of 10 6 --10 10 n/cm 2 s. These include vacuum seals and vacuum chambers of stainless steel and aluminum alloys, solid-state devices for control, diagnostic, and data acquisition electronics, closed-loop cooling-water systems, and insulators. Properties of these materials are degraded by the radiation exposure. Studies of LAMPF and other accelerators, however, have produced solutions to materials problems, allowing the machines to operate for acceptable times without failure. Nevertheless, additional improvements are being investigated in order to further improve operational reliability and safety. 25 refs., 3 figs., 3 tabs

Evaluation of the effects of high energy X-ray radiation in materials used in dental restorations

International Nuclear Information System (INIS)

Maio, Mireia Florencio; Santos, Adimir dos; Fernandes, Marco Antonio Rodrigues

2011-01-01

This work studied the behavior of the physical features and chemical composition of materials used in dental restorations (titanium, amalgam, composite resin and glass ionomer cement) which were submitted to x-ray radiation of 6.0 Mega-Volt (MV) of energy produced in a linear accelerator that is used in radiotherapy of head and neck tumors 1 2. The samples were analyzed using a x-ray fluorescence technique by comparing the chemical composition before and after irradiation. In order to check the residual radiation in the samples, measurements of the sample dosimetry were performed with Geiger-Mueller radiation detectors and an ionization chamber. The samples were also analyzed by gamma-ray spectrometry using a hyper-pure Germanium (HPGe) detector. From these tests, we aimed to verify small changes in the composition of the test bodies due to the radiation. (author)

Evaluation of the effects of high energy X-ray radiation in materials used in dental restorations

Energy Technology Data Exchange (ETDEWEB)

Maio, Mireia Florencio; Santos, Adimir dos, E-mail: mfmaio@ipen.br, E-mail: asantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Fernandes, Marco Antonio Rodrigues, E-mail: marfernandes@fmb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Departamento de Radioterapia

2011-07-01

This work studied the behavior of the physical features and chemical composition of materials used in dental restorations (titanium, amalgam, composite resin and glass ionomer cement) which were submitted to x-ray radiation of 6.0 Mega-Volt (MV) of energy produced in a linear accelerator that is used in radiotherapy of head and neck tumors 1 2. The samples were analyzed using a x-ray fluorescence technique by comparing the chemical composition before and after irradiation. In order to check the residual radiation in the samples, measurements of the sample dosimetry were performed with Geiger-Mueller radiation detectors and an ionization chamber. The samples were also analyzed by gamma-ray spectrometry using a hyper-pure Germanium (HPGe) detector. From these tests, we aimed to verify small changes in the composition of the test bodies due to the radiation. (author)

Laser fusion and high energy density science

International Nuclear Information System (INIS)

Kodama, Ryosuke

2005-01-01

High-power laser technology is now opening a variety of new fields of science and technology using laser-produced plasmas. The laser plasma is now recognized as one of the important tools for the investigation and application of matter under extreme conditions, which is called high energy density science. This chapter shows a variety of applications of laser-produced plasmas as high energy density science. One of the more attractive industrial and science applications is the generation of intense pulse-radiation sources, such as the generation of electro-magnetic waves in the ranges of EUV (Extreme Ultra Violet) to gamma rays and laser acceleration of charged particles. The laser plasma is used as an energy converter in this regime. The fundamental science applications of high energy density physics are shown by introducing laboratory astrophysics, the equation of state of high pressure matter, including warm dense matter and nuclear science. Other applications are also presented, such as femto-second laser propulsion and light guiding. Finally, a new systematization is proposed to explore the possibility of the high energy density plasma application, which is called high energy plasma photonics''. This is also exploration of the boundary regions between laser technology and beam optics based on plasma physics. (author)

High-energy irradiation in the management of chondrosarcoma

International Nuclear Information System (INIS)

Kim, R.Y.; Salter, M.M.; Brascho, D.J.

1983-01-01

We present a retrospective analysis of seven patients with chondrosarcoma of the bone treated by high-energy irradiation between 1961 and 1976. Its major role in this series was prevention of local recurrence in cases with inadequate resection. In three of the five cases in which radiation therapy was adjuvant rather than primary treatment, long-term local control was obtained in a dose of 5,000 to 6,500 rads in five to six weeks. Although primary treatment of chondrosarcoma is surgical, high-dose radiation therapy is indicated when surgical resection is not possible. Chondrosarcoma can respond to high doses of irradiation even though the response is slow

Risk Factors: Radiation

Science.gov (United States)

Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer. Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation.

Coherent spontaneous radiation from highly bunched electron beams

International Nuclear Information System (INIS)

Berryman, K.W.; Crosson, E.R.; Ricci, K.N.

1995-01-01

Coherent spontaneous radiation has now been observed in several FELs, and is a subject of great importance to the design of self-amplified spontaneous emission (SASE) devices. We report observations of coherent spontaneous radiation in both FIREFLY and the mid-infrared FEL at the Stanford Picosecond FEL Center. Coherent emission has been observed at wavelengths as short as 5 microns, and enhancement over incoherent levels by as much as a factor of 4x10 4 has been observed at longer wavelengths. The latter behavior was observed at 45 microns in FIREFLY with short bunches produced by off-peak acceleration and dispersive compression. We present temporal measurements of the highly bunched electron distributions responsible for the large enhancements, using both transition radiation and energy-phase techniques

Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation

Science.gov (United States)

Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.

2012-10-09

Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

Radiation budget studies using collocated observations from advanced Very High Resolution Radiometer, High-Resolution Infrared Sounder/2, and Earth Radiation Budget Experiment instruments

Science.gov (United States)

Ackerman, Steven A.; Frey, Richard A.; Smith, William L.

1992-01-01

Collocated observations from the Advanced Very High Resolution Radiometer (AVHRR), High-Resolution Infrared Sounder/2 (HIRS/2), and Earth Radiation Budget Experiment (ERBE) instruments onboard the NOAA 9 satellite are combined to describe the broadband and spectral radiative properties of the earth-atmosphere system. Broadband radiative properties are determined from the ERBE observations, while spectral properties are determined from the HIRS/2 and AVHRR observations. The presence of clouds, their areal coverage, and cloud top pressure are determined from a combination of the HIRS/2 and the AVHRR observations. The CO2 slicing method is applied to the HIRS/2 to determine the presence of upper level clouds and their effective emissivity. The AVHRR data collocated within the HIRS/2 field of view are utilized to determine the uniformity of the scene and retrieve sea surface temperature. Changes in the top of the atmosphere longwave and shortwave radiative energy budgets, and the spectral distribution of longwave radiation are presented as a function of cloud amount and cloud top pressure. The radiative characteristics of clear sky conditions over oceans are presented as a function of sea surface temperature and atmospheric water vapor structure.

Low energy and high energy dumps for ELI-NP accelerator facility: rational and Monte-Carlo calculations - results

Science.gov (United States)

Esposito, A.; Frasciello, O.; Pelliccioni, M.

2017-09-01

ELI-NP will be a new international research infrastructure facility for laser-based Nuclear Physics to be built in Magurele, south west of Bucharest, Romania. For the machine to operate as an intense γ rays' source based on Compton back-scattering, electron beams are employed, undergoing a two stage acceleration to 320 MeV and 740 MeV (and, with an eventual energy upgrade, also to 840 MeV) beam energies. In order to assess the radiation safety issues, concerning the effectiveness of the dumps in absorbing the primary electron beams, the generated prompt radiation field and the residual dose rates coming from the activation of constituent materials, as well as the shielding of the adjacent environments against both prompt and residual radiation fields, an extensive design study by means of Monte Carlo simulations with FLUKA code was performed, for both low energy 320 MeV and high energy 720 MeV (840 MeV) beam dumps. For the low energy dump we discuss also the rational of the choice to place it in the building basement, instead of installing it in one of the shielding wall at the machine level, as it was originally conceived. Ambient dose equivalent rate constraints, according to the Rumenian law in force in radiation protection matter were 0.1 /iSv/h everywhere outside the shielding walls and 1.4 μiSv/h outside the high energy dump area. The dumps' placements and layouts are shown to be fully compliant with the dose constraints and environmental impact.

High-energy astrophysics and the search for sources of gravitational waves.

Science.gov (United States)

O'Brien, P T; Evans, P

2018-05-28

The dawn of the gravitational-wave (GW) era has sparked a greatly renewed interest into possible links between sources of high-energy radiation and GWs. The most luminous high-energy sources-gamma-ray bursts (GRBs)-have long been considered as very likely sources of GWs, particularly from short-duration GRBs, which are thought to originate from the merger of two compact objects such as binary neutron stars and a neutron star-black hole binary. In this paper, we discuss: (i) the high-energy emission from short-duration GRBs; (ii) what other sources of high-energy radiation may be observed from binary mergers; and (iii) how searches for high-energy electromagnetic counterparts to GW events are performed with current space facilities. While current high-energy facilities, such as Swift and Fermi, play a crucial role in the search for electromagnetic counterparts, new space missions will greatly enhance our capabilities for joint observations. We discuss why such facilities, which incorporate new technology that enables very wide-field X-ray imaging, are required if we are to truly exploit the multi-messenger era.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'. © 2018 The Author(s).

Results of Gamma-Ray Imaging with High-Energy Radiation Visualizer HERV at Nuclear Reactor in Russia and Germany

International Nuclear Information System (INIS)

Ivanov, O.P.; Stepanov, V.E.; Sudarkin, A.N.; Urutskoev, L.I.

1999-01-01

HER V-high energy radiation visualizer is a system for imaging in X-and gamma-ray regions developed by RECOM during recent years. Its later version provides the real industrial prototype that has been already tested under the complex gamma-field conditions of highly contaminated nuclear facilities in Russia and Germany. New special options for initial CCD camera frames processing (CCD camera operates in slow repetition mode) allow one to perform imaging without heavy shielding during a long exposure time. Image processing options allowing one to take into account background radiation, noise and drift of electronics are described. The contaminated pipelines and vessels HER V imagery results are presented. Background does rate in rooms with contaminated equipment appeared to be up to 1 R/hour and from 1m R/hour up to 50 m R/hour at detector's head location. The major contaminating nuclides proved to be Co-60 and Cs-137. Imaging time was chosen to be 0.2-1 hour. Data acquisition and processing procedures enabled to avoid the high background dose rate influence at the device measuring head location. Superposition of gamma images over optical images indicates that the major contaminated parts of the pipelines were their bends, places of their connection, and their valves

Radiation pressure acceleration: The factors limiting maximum attainable ion energy

Energy Technology Data Exchange (ETDEWEB)

Bulanov, S. S.; Esarey, E.; Schroeder, C. B. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Bulanov, S. V. [KPSI, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto 619-0215 (Japan); A. M. Prokhorov Institute of General Physics RAS, Moscow 119991 (Russian Federation); Esirkepov, T. Zh.; Kando, M. [KPSI, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto 619-0215 (Japan); Pegoraro, F. [Physics Department, University of Pisa and Istituto Nazionale di Ottica, CNR, Pisa 56127 (Italy); Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, University of California, Berkeley, California 94720 (United States)

2016-05-15

Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum ion energy.

Vacuum amplification of the high-frequency electromagnetic radiation

OpenAIRE

Vilkovisky, G. A.

1998-01-01

When an electrically charged source is capable of both emitting the electromagnetic waves and creating charged particles from the vacuum, its radiation gets so much amplified that only the backreaction of the vacuum makes it finite. The released energy and charge are calculated in the high-frequency approximation. The technique of expectation values is advanced and employed.

Models of high energy nuclear collisions

International Nuclear Information System (INIS)

Glendenning, N.K.

1978-06-01

The discussion covers nuclear collisions at relativistic energies including classes of high energy nucleus--nucleus collisions, and the kinetics of a central collision; and the asymptotic hadron spectrum including known and unknown hadrons, the relevance of the spectrum and the means of its study, thermodynamics of hadronic matter, examples of hadronic spectra, the temperature, composition of the initial fireball and its expansion, isoergic expansion with no pre-freezeout radiation, isentropic expansion of the fireball, the quasi-dynamical expansion, and finally antinuclei, hypernuclei, and the quark phase. 28 references

5th International Congress on Energy Fluxes and Radiation Effects 2016

International Nuclear Information System (INIS)

2017-01-01

Special Issue of the Materials of the V International Congress on Energy Fluxes and Radiation Effects (Tomsk, Russia, 2016)Maksim Trigub, Georgiy Osokin, Alexander KonovodNational Research Tomsk Polytechnic University, 30, Lenin Avenue, Tomsk, Russiaemail: geosokin@tpu.ruThe present issue of the journal is based on the materials of the V International Congress on Energy Fluxes and Radiation Effects 2016 (EFRE 2016) that was held on October 2 to 7, 2016 in Tomsk (Russia). This large scientific forum gathers together scientists, developers and representatives of knowledge-intensive enterprises that have relevance to physics and technology. This year, the Congress was dedicated to the 120 th anniversary of the National Research Tomsk Polytechnic University.The history of the Congress as a joint scientific event dates back to 2000; it traditionally includes three conferences: International Symposium on High-Current Electronics (SHCE), International Conference on Radiation Physics and Chemistry of Condensed Matter (RPC) and International Conference on Modification of Materials with Particle Beams and Plasma Flows (CMM). However, each of these large conferences has its own lasting history.In 2016, the International Symposium on High-Current Electronics was arranged for the 19 th time. The participants have presented the results of fundamental studies and applied outcomes in the fields of high-power pulsed energy engineering and electronics (Pulsed Power), physics and application of high-power electron and ion beams, high- and low-temperature gas discharge plasma, physics of high-energy treatment and extreme states of matter, electric pulsed technologies. Noteworthy, the symposium took place in the year of the 40 th anniversary of USSR scientific discovery of explosive electron emission. This physical phenomenon—being one of the basics of high-current electronics—determines the processes in pulsed vacuum discharge, enables the operation of high-current electron

Radiation Build-Up In Shielding Of Low Activity High Energia Gamma Source

International Nuclear Information System (INIS)

Helfi-Yuliati; Mukhlis-Akhadi

2003-01-01

Research to observe radiation build-up factor (b) in aluminium (Al), iron (Fe) and lead (Pb) for shielding of gamma radiation of high energy from 137 cs (E γ : 662 keV) source and 60 Co (E γ : 1332 keV) of low activity sources has been carried out. Al with Z =13 represent metal of low atomic number, Fe with Z =26 represent metal of medium atomic number, and Pb with Z = 82 represent metal of high atomic number. Low activity source in this research is source which if its dose rate decrease to 3 % of its initial dose rate became safe for the workers. Research was conducted by counting of radiation intensity behind shielding with its thickness vary from 1 to 5 times of half value thickness (HVT). NaI(TI) detector which connected to multi channel analyzer (MCA) was used for the counting. Calculation result show that all of b value are close to 1 (b ∼ 1) for all kinds of metals. No radiation build-up factor is required in estimating the shielding thickness from several kinds of metals for low activity of high energy gamma source. (author)

Proceedings of the third specialists` meeting on high energy nuclear data

Energy Technology Data Exchange (ETDEWEB)

Fukahori, Tokio [ed.

1998-11-01

This report is the Proceedings of the Third Specialists` Meeting on High Energy Nuclear Data. The meeting was held on March 30-31, 1998, at the Tokai Research Establishment of Japan Atomic Energy Research Institute with the participation of forty-odd specialists, who were the evaluators, theorists, experimentalists and users of high energy nuclear data including the members of the Japanese Nuclear Data Committee. The need of the high energy nuclear data up to a few Gev has been stressed in the meeting for many applications, such as spallation neutron sources for radioactive waste treatment, accelerator shielding design, medical isotope production, radiation therapy, the effects of space radiation on astronauts and their equipments, and the cosmic history of meteorites and other galactic substances. Since the Second Specialists` Meeting in 1995, such an evaluation activity in Japan has been grown and the results are accumulated. Foreign activities of high energy nuclear data evaluation are also being increased. According to the above situation, with the view point of reviewing and validating an evaluated high energy nuclear data file, project of high energy nuclear data file production, differential and integral experiments, status of evaluation and reviewing methods, processing and transport calculation methods, benchmark tests, international trends, etc. were discussed. The 16 of the presented papers are indexed individually. (J.P.N.)

Physics and applications of high energy density plasmas. Extreme state driven by pulsed electromagnetic energy

International Nuclear Information System (INIS)

Horioka, Kazuhiko

2002-06-01

The papers presented at the symposium on ''Physics and application of high energy density plasmas, held December 20-21, 2001 at NIFS'' are collected in this proceedings. The topics covered in the meeting include dense z-pinches, plasma focus, intense charged particle beams, intense radiation sources, discharge pumped X-ray lasers, their diagnostics, and applications of them. The papers reflect the present status and trends in the research field of high energy density plasmas. (author)

High energy radiation precursors to the collapse of black holes binaries based on resonating plasma modes

Science.gov (United States)

Coppi, B.

2018-05-01

The presence of well organized plasma structures around binary systems of collapsed objects [1,2] (black holes and neutron stars) is proposed in which processes can develop [3] leading to high energy electromagnetic radiation emission immediately before the binary collapse. The formulated theoretical model supporting this argument shows that resonating plasma collective modes can be excited in the relevant magnetized plasma structure. Accordingly, the collapse of the binary approaches, with the loss of angular momentum by emission of gravitational waves [2], the resonance conditions with vertically standing plasma density and magnetic field oscillations are met. Then, secondary plasma modes propagating along the magnetic field are envisioned to be sustained with mode-particle interactions producing the particle populations responsible for the observable electromagnetic radiation emission. Weak evidence for a precursor to the binary collapse reported in Ref. [2], has been offered by the Agile X-γ-ray observatory [4] while the August 17 (2017) event, identified first by the LIGO-Virgo detection of gravitational waves and featuring the inferred collapse of a neutron star binary, improves the evidence of such a precursor. A new set of experimental observations is needed to reassess the presented theory.

Evaluation of solar radiation abundance and electricity production capacity for application and development of solar energy

Energy Technology Data Exchange (ETDEWEB)

Rahim, Mustamin [Department of Architecture, Khairun University, Ternate (Indonesia); Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University (Japan); Yoshino, Jun; Yasuda, Takashi [Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University (Japan)

2012-07-01

This study was undertaken to analyze solar radiation abundance to ascertain the potential of solar energy as an electrical energy resource. Local weather forecasting for predicting solar radiation is performed using a meteorological model MM5. The prediction results are compared with observed results obtained from the Japan Meteorological Agency for verification of the data accuracy. Results show that local weather forecasting has high accuracy. Prediction of solar radiation is similar with observation results. Monthly average values of solar radiation are sufficiently good during March–September. Electrical energy generated by photovoltaic cells is almost proportional to the solar radiation amount. Effects of clouds on solar radiation can be removed by monthly averaging. The balance between supply and demand of electricity can be estimated using a standard curve obtained from the temporal average. When the amount of solar radiation every hour with average of more than 100 km radius area does not yield the standard curve, we can estimate the system of storage and auxiliary power necessary based on the evaluated results of imbalance between supply and demand.

Science on high-energy lasers: From today to the NIF

International Nuclear Information System (INIS)

Lee, R.W.; Petrasso, R.; Falcone, R.W.

1995-01-01

This document presents both a concise definition of the current capabilities of high energy lasers and a description of capabilities of the NIF (National Ignition Facility). Five scientific areas are discussed (Astrophysics, Hydrodynamics, Material Properties, Plasma Physics, Radiation Sources, and Radiative Properties). In these five areas we project a picture of the future based on investigations that are being carried on today. Even with this very conservative approach we find that the development of new higher energy lasers will make many extremely exciting areas accessible to us

High-energy neutrinos from gamma ray bursts

International Nuclear Information System (INIS)

Dermer, Charles D.; Atoyan, Armen

2003-01-01

We treat high-energy neutrino production in gamma ray bursts (GRBs). Detailed calculations of photomeson neutrino production are presented for the collapsar model, where internal nonthermal synchrotron radiation is the primary target photon field, and the supranova model, where external pulsar-wind synchrotron radiation provides important additional target photons. Detection of > or approx. 10 TeV neutrinos from GRBs with Doppler factors > or approx. 200, inferred from γ-ray observations, would support the supranova model. Detection of or approx. 3x10 -4 erg cm -2 offer a realistic prospect for detection of ν μ

Effects of sterilisation by high-energy radiation on biomedical poly-(epsilon-caprolactone)/hydroxyapatite composites.

Science.gov (United States)

Di Foggia, Michele; Corda, Ugo; Plescia, Elena; Taddei, Paola; Torreggiani, Armida

2010-06-01

The effects of a high energy sterilization treatment on poly-epsilon-caprolactone/carbonated hydroxyapatite composites have been investigated. Poly-epsilon-caprolactone is a biodegradable polymer used as long-term bioresorbable scaffold for bone tissue engineering and carbonated hydroxyapatite is a bioactive material able to promote bone growth. The composites were gamma-irradiated in air or under nitrogen atmosphere with doses ranging from 10 to 50 kGy (i.e. to a value higher than that recommended for sterilization). The effects of the irradiation treatment were evaluated by vibrational spectroscopy (IR and Raman spectroscopies) coupled to thermal analysis (Differential Scanning Calorimetry and Thermogravimetry) and Electron Paramagnetic Resonance spectroscopy. Irradiation with the doses required for sterilization induced acceptable structural changes and damaging effects: only a very slight fragmentation of the polymeric chains and some defects in the inorganic component were observed. Moreover, the radiation sensitivity of the composites proved almost the same under the two different atmospheres.

Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

International Nuclear Information System (INIS)

Hill, K.W.; Bell, M.G.; Budny, R.

1999-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≥ 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

International Nuclear Information System (INIS)

Hill, K.W.; Bell, M.G.; Budny, R.

2001-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≤30MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

Moderate Image Spectrometer (MODIS) Fire Radiative Energy: Physics and Applications

Science.gov (United States)

Kaufman, Y.

2004-01-01

MODIS fire channel does not saturate in the presence of fires. The fire channel therefore is used to estimate the fire radiative energy, a measure of the rate of biomass consumption in the fire. We found correlation between the fire radiative energy, the rate of formation of burn scars and the rate of emission of aerosol from the fires. Others found correlations between the fire radiative energy and the rate of biomass consumption. This relationships can be used to estimates the emissions from the fires and to estimate the fire hazards.

High technology for radiation application

International Nuclear Information System (INIS)

Iida, Toshiyuki

2005-03-01

Fundamentals of radiations, radioactivity, and their applications in recent industrial, medical, agricultural and various research fields are reviewed. The book begins with historical description regarding to discovery of radiation at the end of 19th century and the exploration into the inside of an atom utilizing the radiation discovered, discovery of the neutron which finally leaded to nuclear energy liberation. Developments of radiation sources, including nuclear reactors, and charged-particle accelerators follow with simultaneous description on radiation measurement or detection technology. In medical fields, X-ray diagnosis, interventional radiology (IVR), nuclear medicine (PET and others), and radiation therapy are introduced. In pharmaceutical field, synthesis of labeled compounds and tracer techniques are explained. In industrial application, radiation-reinforced wires and heat-resistant cables whose economic effect can be estimated to amount to more than 10 12 yen, radiation mutation, food irradiation, and applied accelerators such as polymer modifications, decomposition of environmentally harmful substances, and ion-implantations important in semiconductor device fabrication. Finally, problems relating to general public such as radiation education and safety concept are also discussed. (S. Ohno)

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.

Examination of spent fuel radiation energy conversion for electricity generation

Energy Technology Data Exchange (ETDEWEB)

Lee, Haneol; Yim, Man-Sung, E-mail: msyim@kaist.ac.kr

2016-04-15

Highlights: • Utilizing conversion of radiation energy of spent fuel to electric energy. • MCNPX modeling and experiment were used to estimate energy conversion. • The converted energy may be useful for nuclear security applications. • The converted energy may be utilized for safety applications through energy storage. - Abstract: Supply of electricity inside nuclear power plant is one of the most important considerations for nuclear safety and security. In this study, generation of electric energy by converting radiation energy of spent nuclear fuel was investigated. Computational modeling work by using MCNPX 2.7.0 code along with experiment was performed to estimate the amount of electric energy generation. The calculation using the developed modeling work was validated through comparison with an integrated experiment. The amount of electric energy generation based on a conceptual design of an energy conversion module was estimated to be low. But the amount may be useful for nuclear security applications. An alternative way of utilizing the produced electric energy could be considered for nuclear safety application through energy storage. Further studies are needed to improve the efficiency of the proposed energy conversion concept and to examine the issue of radiation damage and economic feasibility.

Effect of Varieties and Plant Population Densities on Dry Matter Production, Radiation Interception and Radiation Energy Conversion in Peanut

Directory of Open Access Journals (Sweden)

agus suprapto

2012-05-01

Full Text Available The solar radiation is one of the major criteria to obtaining advantages on peanuts (Arachishypogaea L.. Although various combinations of crops have been reported, but variety association and plant population densities (PPD during the periodically stage of growth on peanuts have yet to be analyzed. Dry matter production (DM, radiation energy interception, and radiation energy conversions were monitored over the growth period of two varieties of peanut. An experiment was conducted in Jambegede Research Farm, Indonesian Legume and Tuber Crops Research Institute, Malang, East Java, Indonesia, from July until October 2011. The experiment was arranged in a Split Plot Design with three replications. Peanut varieties, as the main plot consisted of two treatments: Kelinci andKancil variety. In addition, five PPD variations as sub plot consisted of 8.1, 11.1, 16.0, 25.0 and 44.4 plant m-2 were arranged in a square spacing. The results showed that DM production from high PPD increased gradually to lower PPD in all varieties. Interception efficiency (IE increased in all varieties from early sowing. A plant population density of 25.0 m-2 and 44.4 plants m-2 intercepted more radiation over 11.1 or 16.0 plants m-2. Conversion efficiency of radiation energy (CE to total dry matter production on Kelinci variety (1.52% indicated a slight higher percentage than on Kancil variety (1.41%. Moreover, the CE and IE values indicated a decrease as the PPD increased on maximum DM.

Radiation energy collector

Energy Technology Data Exchange (ETDEWEB)

Chao, Bei Tse; Rabl, A

1977-02-10

The invention deals with a concentrating solar collector. Collectors of this kind often have considerable natural convection losses which are due, among other facts, to the location of the energy absorber at the outlet with the heated surface of the absorber facing the inlet opening of the collector. According to the invention, the collector is designed in such manner that the absorber is located inside a space in such a way that the radiation emitted by the absorber is reflected back to the absorber with the aid of mirror surfaces. Various designs are described.

Radiation protection in nuclear energy. V.1

International Nuclear Information System (INIS)

1988-01-01

The conference was convened to provide a forum for the exchange of international views on the principles of radiation protection for regulators and practitioners, to highlight issues of current importance, to examine the problems encountered in applying the principles of radiation protection, and, where possible, to identify generic solutions. A special session entitled ''The dose-response relationship: implications for nuclear energy'', and a panel on ''Radiation protection education and training'' were included in the conference programme. Refs, figs and tabs

Radiation effects, nuclear energy and comparative risks

International Nuclear Information System (INIS)

Gopinath, D.V.

2007-01-01

Nuclear energy had a promising start as an unlimited, inexpensive and environmentally benign source of energy for electricity generation. However, over the decades its growth was severely retarded due to concerns about its possible detrimental effects on the well-being of mankind and the environment. Since such concerns are essentially due to the gigantic magnitude of radioactivity and ionizing radiations associated with nuclear energy, this article starts with a comprehensive account of effects of the ionizing radiation on living systems. Quantitative description of types of radiation exposure and their varied effects is given. The origin, type and magnitude of mutagenic effects of radiation are described. The concept of radiation risk factors, basis for their evaluation and their currently accepted values are presented. With this background, origin and magnitude of radioactivity and associated ionizing radiations in nuclear reactors are presented and the elaborate measures to contain them are described. It is recognized that notwithstanding all the measures taken in the nuclear industry, certain amount of radiation exposure, however small, is inevitable and the values, based on the experience world over, are presented. Estimated health risk due to such exposures is evaluated. For a comparative analysis, risks in other options of electricity generation such as hydel and fossil-fuelled plants are described. It is seen that on an overall basis, the nuclear option is no more risky than the other commonly employed options, and is in fact, significantly less. Lastly, since every option of electricity generation entails some risk, the case of 'no addition of electricity, and its impact on the society are considered. Based on the analysis of extensive data provided by UNDP on the human development parameters for different countries in the world, it is shown that at least for developing countries, any option of addition of electricity would be far more desirable than the

Lightweight Damage Tolerant, High-Temperature Radiators for Nuclear Power and Propulsion

Science.gov (United States)

Craven, Paul D.; SanSoucie, Michael P.

2015-01-01

NASA is increasingly emphasizing exploration to bodies beyond near-Earth orbit. New propulsion systems and new spacecraft are being built for these missions. As the target bodies get further out from Earth, high energy density systems, e.g., nuclear fusion, for propulsion and power will be advantageous. The mass and size of these systems, including supporting systems such as the heat exchange system, including thermal radiators, will need to be as small as possible. Conventional heat exchange systems are a significant portion of the total thermal management mass and size. Nuclear electric propulsion (NEP) is a promising option for high-speed, in-space travel due to the high energy density of nuclear fission power sources and efficient electric thrusters. Heat from the reactor is converted to power for use in propulsion or for system power. The heat not used in the power conversion is then radiated to space as shown in figure 1. Advanced power conversion technologies will require high operating temperatures and would benefit from lightweight radiator materials. Radiator performance dictates power output for nuclear electric propulsion systems. Pitch-based carbon fiber materials have the potential to offer significant improvements in operating temperature, thermal conductivity, and mass. These properties combine to allow significant decreases in the total mass of the radiators and significant increases in the operating temperature of the fins. A Center-funded project at NASA Marshall Space Flight Center has shown that high thermal conductivity, woven carbon fiber fins with no matrix material, can be used to dissipate waste heat from NEP systems and because of high specific power (kW/kg), will require less mass and possibly less total area than standard metal and composite radiator fins for radiating the same amount of heat. This project uses an innovative approach to reduce the mass and size required for the thermal radiators to the point that in-space NEP and power

Non-combustible nuclear radiation shields with high hydrogen content

International Nuclear Information System (INIS)

Hall, W.C.; Peterson, J.M.

1978-01-01

The invention relates to compositions, methods of production, and uses of non-combustible nuclear radiation shields, with particular emphasis on those containing a high concentration of hydrogen atoms, especially effective for moderating neutron energy by elastic scatter, dispersed as a discontinuous phase in a continuous phase of a fire resistant matrix

Physics and applications of high energy density plasmas. Extreme state driven by pulsed electromagnetic energy

Energy Technology Data Exchange (ETDEWEB)

Horioka, Kazuhiko (ed.)

2002-06-01

The papers presented at the symposium on ''Physics and application of high energy density plasmas, held December 20-21, 2001 at NIFS'' are collected in this proceedings. The topics covered in the meeting include dense z-pinches, plasma focus, intense charged particle beams, intense radiation sources, discharge pumped X-ray lasers, their diagnostics, and applications of them. The papers reflect the present status and trends in the research field of high energy density plasmas. (author)

Direct energy conversion of radiation energy in fusion reactor

International Nuclear Information System (INIS)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author)

Direct energy conversion of radiation energy in fusion reactor

Science.gov (United States)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned.

Direct energy conversion of radiation energy in fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author).

Direct energy conversion of radiation energy in fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S. [National Inst. for Fusion Science, Nagoya (Japan); Ohnishi, M.; Onozuka, M.; Uenosono, C.

1994-12-31

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author).

Direct energy conversion of radiation energy in fusion reactor

International Nuclear Information System (INIS)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1994-01-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author)

Low energy and high energy dumps for ELI-NP accelerator facility: rational and Monte-Carlo calculationsș results

Directory of Open Access Journals (Sweden)

Esposito A.

2017-01-01

Full Text Available ELI-NP will be a new international research infrastructure facility for laser-based Nuclear Physics to be built in Magurele, south west of Bucharest, Romania. For the machine to operate as an intense γ rays’ source based on Compton back-scattering, electron beams are employed, undergoing a two stage acceleration to 320 MeV and 740 MeV (and, with an eventual energy upgrade, also to 840 MeV beam energies. In order to assess the radiation safety issues, concerning the effectiveness of the dumps in absorbing the primary electron beams, the generated prompt radiation field and the residual dose rates coming from the activation of constituent materials, as well as the shielding of the adjacent environments against both prompt and residual radiation fields, an extensive design study by means of Monte Carlo simulations with FLUKA code was performed, for both low energy 320 MeV and high energy 720 MeV (840 MeV beam dumps. For the low energy dump we discuss also the rational of the choice to place it in the building basement, instead of installing it in one of the shielding wall at the machine level, as it was originally conceived. Ambient dose equivalent rate constraints, according to the Rumenian law in force in radiation protection matter were 0.1 /iSv/h everywhere outside the shielding walls and 1.4 μiSv/h outside the high energy dump area. The dumps’ placements and layouts are shown to be fully compliant with the dose constraints and environmental impact.

Radiation exposure and high-altitude flight. NCRP Commentary No. 12

International Nuclear Information System (INIS)

1995-01-01

Enhanced air crew and public radiation exposure while flying at current altitudes and speeds has not been adequately addressed. However, the commercial aircraft industry continues to expand with greater numbers of passengers and more air crews year by year. With the expected expansions in high-altitude flight in the next two decades there will be many more people exposed to higher levels of ionizing radiation than currently. The equivalent dose rates at the higher altitudes are of the order of two to three times those received at current aircraft altitudes, but are not known very well, partly because of limitations in the knowledge of the component radiations, especially the high-energy neutron component. The risks are also more uncertain than for low-LET exposures on the ground because of uncertainty in an average W R to use for high-LET radiations. Exposures of current air crew are presently comparable with the average exposures of other radiation workers on the ground (EPA, 1995). Substantially higher exposures must be expected at high altitudes to air crew (perhaps approaching or possibly exceeding the current limit for workers on the ground). Higher exposures to sensitive groups of the population such as the fetuses carried by pregnant women are of special concern. Therefore, steps must be taken to improve our knowledge base with respect to dose levels and risks at these high altitudes. Following acquisition of this knowledge, modifications in radiation protection practices with respect to air crew and passengers will need to be considered and recommended to assure that adequate radiation protection is provided with respect to high-altitude flight

Safety consequences of the release of radiation induced stored energy

International Nuclear Information System (INIS)

Prij, J.

1994-08-01

Due to the disposal of HLW in a salt formation gamma energy will be deposited in the rock salt. Most of this energy will be converted into heat, whilst a small part will create defects in the salt crystals. Energy is stored in the damaged crystals. Due to uncertainties in the models and differences in the disposal concepts the estimated values for the stored energy range from 10 to 1000 J/g in the most heavily damaged crystals close to the waste containers. The amount of radiation damage decays exponentially with increasing distance from the containers and at distances larger than 0.2 m the stored energy can be neglected. Given the uncertainties in the model predictions and in the possible release mechanism an instantaneous release of stored energy cannot be excluded completely. Therefore the thermo-mechanical consequences of a postulated instantaneous release of an extremely high amount of radiation induced stored energy have been estimated. These estimations are based on the quasi-static solutions for line and point sources. To account for the dynamic effects and the occurrence of fractures an amplification factor has been derived from mining experience with explosives. A validation of this amplification factor has been given using post experimental observations of two nuclear explosions in a salt formation. For some typical disposal concepts in rock salt the extent of the fractured zone has been estimated. It appeared that the radial extent of the fractured zone is limited to 5 m. Given the much larger distance between the individual boreholes and the distance between the boreholes and the boundary of the salt formation (more than 100 m), the probability of a release of radiation induced stored energy creating a pathway for the nuclides from the containers to the groundwater, is extremely low. The radiological consequences of a groundwater intrusion scenario induced by this very unprobable pathway are bounded by the 'standard' groundwater intrusion

Radiation effects for high-energy protons and X-ray in integrated circuits

Energy Technology Data Exchange (ETDEWEB)

Silveira, M.A.G.; Santos, R.B.B. [Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil); Medina, N.H.; Added, N.; Tabacniks, M.H. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Lima, J.A. de [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Cirne, K.H. [Empresa Brasileira de Aeronautica S.A. (EMBRAER), Sao Jose dos Campos, SP (Brazil)

2012-07-01

Full text: Electronic circuits are strongly influenced by ionizing radiation. The necessity to develop integrated circuits (IC's) featuring radiation hardness is largely growing to meet the stringent environment in space electronics [1]. This work aims to development a test platform to qualify electronic devices under the influence of high radiation dose, for aerospace applications. To understand the physical phenomena responsible for changes in devices exposed to ionizing radiation several kinds of radiation should then be considered, among them heavy ions, alpha particles, protons, gamma and X-rays. Radiation effects on the ICs are usually divided into three categories: Total Ionizing Dose (TID), a cumulative dose that shifts the threshold voltage and increases transistor's off-state current; Single Events Effects (SEE), a transient effect which can deposit charge directly into the device and disturb the properties of electronic circuits and Displacement Damage (DD) which can change the arrangement of the atoms in the lattice [2]. In this study we are investigating the radiation effects in rectangular-gate and circular-gate MOSFETs, manufactured with standard CMOS fabrication process, using particle beams produced in electrostatic tandem accelerators and X-rays. Initial tests for TID effects were performed using the 1.7 MV 5SDH tandem Pelletron accelerator of the Instituto de Fisica da USP with a proton beam of 2.6 MeV. The devices were exposed to different doses, varying the beam current, and irradiation time with the accumulated dose reaching up to Grad. To study the effect of X-rays on the electronic devices, an XRD-7000 (Shimadzu) X-ray setup was used as a primary X-ray source. The devices were irradiated with a total dose from krad to Grad using different dose rates. The results indicate that changes of the I-V characteristic curve are strongly dependents on the geometry of the devices. [1] Duzellier, S., Aerospace Science and Technology 9, p. 93

High-let radiation carcinogenesis

International Nuclear Information System (INIS)

Fry, R.J.M.; Powers-Risius, P.; Alpen, E.L.; Ainsworth, E.J.; Ullrich, R.L.

1982-01-01

Recent results for neutron radiation-induced tumors are presented to illustrate the complexities of the dose-response curves for high-LET radiation. It is suggested that in order to derive an appropriate model for dose-response curves for the induction of tumors by high-LET radiation it is necessary to take into account dose distribution, cell killing and the susceptibility of the tissue under study. Preliminary results for the induction of Harderian gland tumors in mice exposed to various heavy ion beams are presented. The results suggest that the effectiveness of the heavy ion beams increases with increasing LET. The slopes of the dose-response curves for the different high-LET radiations decrease between 20 and 40 rads and therefore comparisons of the relative effectiveness should be made from data obtained at doses below about 20 to 30 rads

Development of dose monitoring system applicable to various radiations with wide energy ranges

International Nuclear Information System (INIS)

Sato, Tatsuhiko; Satoh, Daiki; Endo, Akira; Yamaguchi, Yasuhiro

2005-01-01

A new inventive radiation dose monitor, designated as DARWIN (Dose monitoring system Applicable to various Radiations with WIde energy raNges), has been developed for monitoring doses in workspaces and surrounding environments of high energy accelerator facilities. DARWIN is composed of a phoswitch-type scintillation detector, which consists of liquid organic scintillator BC501A coupled with ZnS(Ag) scintillation sheets doped with 6 Li, and a data acquisition system based on a Digital-Storage-Oscilloscope. Scintillations from the detector induced by thermal and fast neutrons, photons and muons were discriminated by analyzing their waveforms, and their light outputs were directly converted into the corresponding doses by applying the G-function method. Characteristics of DARWIN were studied by both calculation and experiment. The calculated results indicate that DARWIN gives reasonable estimations of doses in most radiation fields. It was found from the experiment that DARWIN has an excellent property of measuring doses from all particles that significantly contribute to the doses in surrounding environments of accelerator facilities - neutron, photon and muon with wide energy ranges. The experimental results also suggested that DARWIN enables us to monitor small fluctuation of neutron dose rates near the background-level owing to its high sensitivity. (author)

Dispersive effects in radiation transport and radiation hydrodynamics in matter at high density

International Nuclear Information System (INIS)

Crowley, B.J.B.

1983-01-01

In a recent research program (reported in AWRE 0 20/82) I have investigated the generalisation of the equations of radiation hydrodynamics when electromagnetic radiation is assumed to obey a linear-response dispersion relation of the form nω=kc where the refractive index n depends on the frequency ω and/or wave number k. From the application of the Boltzmann-Liouville transport theory to photons in the short-wavelength (geometrical optics) limit, I derive the energy and momentum equations which, when combined with a classical (Euler-Lagrange-Navier-Stokes) treatment of a fluid material medium in LTE, yield a complete dynamical theory of linear interactions (+ stimulated processes) between incoherent (thermal) radiation and dense, locally isotropic matter. The theory includes an account of pondero-motive forces and electro (magneto) striction. Moreover, it is apparently capable of being generalised to non-linear interactions in which the refractive index depends on the local specific intensity of the radiation field, and, to some extent, to the treatment of high-frequency coherent radiation. The generalisation of various approximated forms of radiation-transport theory (esp. diffusion) has been considered in detail. Some problems remain however. One such is the treatment of anomalous dispersion. Current research work is concentrating on the interesting atomic physics aspects of electromagnetic (esp. radiative) properties of a dispersive material medium

Induction and Persistence of Large γH2AX Foci by High Linear Energy Transfer Radiation in DNA-Dependent protein kinase–Deficient Cells

Energy Technology Data Exchange (ETDEWEB)

Bracalente, Candelaria; Ibañez, Irene L. [Departamento de Micro y Nanotecnología, Comisión Nacional de Energía Atómica, San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires (Argentina); Molinari, Beatriz [Departamento de Radiobiología, Comisión Nacional de Energía Atómica, San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires (Argentina); Palmieri, Mónica [Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina); Kreiner, Andrés [Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires (Argentina); Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, San Martín, Buenos Aires (Argentina); Valda, Alejandro [Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, San Martín, Buenos Aires (Argentina); and others

2013-11-15

Purpose: To evaluate the cell response to DNA double-strand breaks induced by low and high linear energy transfer (LET) radiations when the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an essential protein of the nonhomologous end-joining repair pathway, lacks kinase activity. Methods and Materials: CHO10B2, a Chinese hamster ovary cell line, and its derived radiosensitive mutant cell line, irs-20, lacking DNA-PKcs activity, were evaluated after 0 to 3 Gy of γ-rays, plateau and Bragg peak protons, and lithium beams by clonogenic assay, and as a measurement of double-strand breaks, phosphorylated H2AX (γH2AX) foci number and size were quantified by immunocytofluorescence. Results: Irs-20 exhibited greater radiosensitivity and a higher amount of γH2AX foci than CHO10B2 at 6 hours after irradiation for all types of radiations. Remarkably, CHO10B2 and irs-20 maintained their difference in radiosensitivity after high-LET radiation. Six hours after low-LET radiations, irs-20 did not reach basal levels of γH2AX at high doses, whereas CHO10B2 recovered basal levels for all doses. After high-LET radiation, only CHO10B2 exhibited a reduction in γH2AX foci, but it never reached basal levels. Persistent foci in irs-20 confirmed a repair deficiency. Interestingly, after 30 minutes of high-LET radiation both cell lines exhibited large foci (size >0.9 μm{sup 2}) related to the damage nature, whereas at 6 hours irs-20 showed a higher amount of large foci than CHO10B2, with a 7-fold increase at 3 Gy, that could also be associated to radiosensitivity. Conclusions: We demonstrated, for the first time, an association between deficient DNA-PKcs activity and not only high levels of H2AX phosphorylation but also persistence and size increase of γH2AX foci after high-LET irradiation.

Induction and Persistence of Large γH2AX Foci by High Linear Energy Transfer Radiation in DNA-Dependent protein kinase–Deficient Cells

International Nuclear Information System (INIS)

Bracalente, Candelaria; Ibañez, Irene L.; Molinari, Beatriz; Palmieri, Mónica; Kreiner, Andrés; Valda, Alejandro

2013-01-01

Purpose: To evaluate the cell response to DNA double-strand breaks induced by low and high linear energy transfer (LET) radiations when the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an essential protein of the nonhomologous end-joining repair pathway, lacks kinase activity. Methods and Materials: CHO10B2, a Chinese hamster ovary cell line, and its derived radiosensitive mutant cell line, irs-20, lacking DNA-PKcs activity, were evaluated after 0 to 3 Gy of γ-rays, plateau and Bragg peak protons, and lithium beams by clonogenic assay, and as a measurement of double-strand breaks, phosphorylated H2AX (γH2AX) foci number and size were quantified by immunocytofluorescence. Results: Irs-20 exhibited greater radiosensitivity and a higher amount of γH2AX foci than CHO10B2 at 6 hours after irradiation for all types of radiations. Remarkably, CHO10B2 and irs-20 maintained their difference in radiosensitivity after high-LET radiation. Six hours after low-LET radiations, irs-20 did not reach basal levels of γH2AX at high doses, whereas CHO10B2 recovered basal levels for all doses. After high-LET radiation, only CHO10B2 exhibited a reduction in γH2AX foci, but it never reached basal levels. Persistent foci in irs-20 confirmed a repair deficiency. Interestingly, after 30 minutes of high-LET radiation both cell lines exhibited large foci (size >0.9 μm 2 ) related to the damage nature, whereas at 6 hours irs-20 showed a higher amount of large foci than CHO10B2, with a 7-fold increase at 3 Gy, that could also be associated to radiosensitivity. Conclusions: We demonstrated, for the first time, an association between deficient DNA-PKcs activity and not only high levels of H2AX phosphorylation but also persistence and size increase of γH2AX foci after high-LET irradiation

The measurement of attenuation coefficients at low photon energies using fluorescent x-radiation

International Nuclear Information System (INIS)

Peaple, L.H.J.; White, D.R.

1978-03-01

A rapid and accurate method has been developed to measure low energy attenuation coefficients for materials of importance in radiation dosimetry. It employs a collimated beam of fluorescent x-rays from which the required radiation is selected by means of a high resolution germanium detector and multi-channel analyser. The method is described in detail and its accuracy and application outlined with reference to the results from nine different materials. (author)

Frontiers for Discovery in High Energy Density Physics

Energy Technology Data Exchange (ETDEWEB)

Davidson, R. C.; Katsouleas, T.; Arons, J.; Baring, M.; Deeney, C.; Di Mauro, L.; Ditmire, T.; Falcone, R.; Hammer, D.; Hill, W.; Jacak, B.; Joshi, C.; Lamb, F.; Lee, R.; Logan, B. G.; Melissinos, A.; Meyerhofer, D.; Mori, W.; Murnane, M.; Remington, B.; Rosner, R.; Schneider, D.; Silvera, I.; Stone, J.; Wilde, B.; Zajc. W.

2004-07-20

The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics

Internal high linear energy transfer (LET) targeted radiotherapy for cancer

International Nuclear Information System (INIS)

Allen, Barry J

2006-01-01

High linear energy transfer (LET) radiation for internal targeted therapy has been a long time coming on to the medical therapy scene. While fundamental principles were established many decades ago, the clinical implementation has been slow. Localized neutron capture therapy, and more recently systemic targeted alpha therapy, are at the clinical trial stage. What are the attributes of these therapies that have led a band of scientists and clinicians to dedicate so much of their careers? High LET means high energy density, causing double strand breaks in DNA, and short-range radiation, sparing adjacent normal tissues. This targeted approach complements conventional radiotherapy and chemotherapy. Such therapies fail on several fronts. Foremost is the complete lack of progress for the control of primary GBM, the holy grail for cancer therapies. Next is the inability to regress metastatic cancer on a systemic basis. This has been the task of chemotherapy, but palliation is the major application. Finally, there is the inability to inhibit the development of lethal metastatic cancer after successful treatment of the primary cancer. This review charts, from an Australian perspective, the developing role of local and systemic high LET, internal radiation therapy. (review)

Effect of quantum fluctuations of synchrotron radiation on the dynamics of particles in high-energy microtrons

International Nuclear Information System (INIS)

Bessonov, E.G.

1987-01-01

Crosbie has demonstrated numerically that the effect of quantum fluctuation of synchrotron radiation on the beam emittance becomes significant in microtrons for an energy of more than 1 GeV. In this paper the authors give analytic expressions that describe this phenomenon and analyze these expressions