Characterization of the radiation field of a 137Cs source in a calibration laboratory

International Nuclear Information System (INIS)

Barbosa, E.F.; Freitas, C.; Freire, D.; Almeida, C.E.

2001-01-01

Due to the broad range of radiation levels found in practice, the calibration of radiation detector requires that the laboratory have a large range of values of air kerma rates for a reference distance to the source, in order to allow the calibration of all scales. The dosimetry performed for open beam and with the different attenuators has shown deviations smaller than 5% in relation to the data supplied by the manufacturer that is acceptable. These results are in accordance with the recommendations of the ISO/DIS 4037-2

Review of radiation safety in the cardiac catheterization laboratory

International Nuclear Information System (INIS)

Johnson, L.W.; Moore, R.J.; Balter, S.

1992-01-01

With the increasing use of coronary arteriography and interventional procedures, radiation exposure to patients and personnel working in cardiac catheterization laboratories has increased. Proper technique to minimize both patient and operator exposure is necessary. A practical approach to radiation safety in the cardiac catheterization laboratory is presented. This discussion should be useful to facilities with well-established radiation safety programs as well as facilities that require restructuring to cope with the radiation environment in a modern cardiac catheterization laboratory

Neutron and photon spectrometry in mixed radiation fields

International Nuclear Information System (INIS)

Jancar, A.; Kopecky, Z.; Veskrna, M.

2014-01-01

Spectrometric measurements of the mixed fields of neutron and photon radiation in the workplaces with the L-R-0 research reactor located in the UJV Rez and with the Van de Graaff accelerator, located in the UTEF laboratories Prague, are presented in this paper. The experimental spectrometric measurements were performed using a newly developed digital measuring system, based on the technology of analog-digital converters with a very high sampling frequency (up to 2 GHz), in connection with organic scintillation detector, type BC-501A, and stilbene detector. The results of experimental measurements show high quality of spectrometry mixed fields of neutron and photon radiation across the wide dynamic range of measured energy. (authors)

Trends in instrumentation for environmental radiation measurements at Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Hiebert, R.D.; Wolf, M.A.

1980-01-01

Recent instruments developed to fulfill radiation monitoring needs at Los Alamos Scientific Laboratory are described. Laboratory instruments that measure tritium gas effluents alone, or in the presence of activated air from D-T fusion reactors are discussed. Fully portable systems for gamma, x-ray, and alpha analyses in the field are described. Also included are descriptions of survey instruments that measure low levels of transuranic contaminants and that measure pulsed-neutron dose rates

Radiation monitoring programme in a university hot laboratory

International Nuclear Information System (INIS)

Tillander, M.; Heinonen, O.J.

1979-01-01

The Department of Radiochemistry in the University of Helsinki is the only institute teaching radiochemistry at the university level in Finland. The research programme of the Deparment must therefore include the uses of radiation and radionuclides in many branches of science. The students must receive adequate instruction in radiation protection for safe work in laboratories. This also has the educational benefit that the radiochemists will subsequently be able to observe the necessary safety precautions when employing ionizing radiation professionally. The Department of Radiochemistry consists of the following laboratories: a radiotracer laboratory, a neutron/electron and a gamma irradiation laboratory, an environmental low activity level laboratory, a whole-body counting laboratory, a reactor chemistry laboratory and a waste-treatment facility. The radiation protection organization of the Department is presented. Various methods of monitoring, including advantages and disadvantages are discussed. Emphasis is placed on the reactor chemistry laboratory where transuranic elements are utilized. These elements are highly radiotoxic and their monitoring in most cases requires destructive analysis. Different methods of determining external and internal doses are evaluated with regard to sensitivity and accuracy. Detection limits for radionuclides utilized in the laboratory are presented for different measurement systems, including non-destructive monitoring, spectrometry after chemical analysis, liquid scintillation counting and low-energy gamma spectrometry using a CsI-NaI scintillation detector. The guidelines laid down in the IAEA Safety Series Manuals are discussed in the light of practical experience. (author)

National Laboratory of Synchrotron Radiation: technologic potential

International Nuclear Information System (INIS)

Silva, C.E.T.G. da; Rodrigues, A.R.D.

1987-01-01

The technological or industrial developments based on the accumulated experience by research group of condensed matter physics, in Brazil, are described. The potential of a National Laboratory of Synchrotron Radiation for personnel training, absorption and adaptation of economically important technologies for Brazil, is presented. Examples of cooperations between the Laboratory and some national interprises, and some industrial applications of the synchrotron radiation are done. (M.C.K.) [pt

Characteristics of the radiation prevention metrology laboratory 'Cajavec' - Banjaluka

International Nuclear Information System (INIS)

Tomljenovic, I.; Ninkovic, M.; Kolonic, Dz.

2004-01-01

Radiation metrology laboratory built in the factory 'Cajavec' in Banja Luka, planed for gauge the detectors of ionization radiation. Laboratory as part of the large factory building , thus projected and formed according to positive radiation principles. Walls are constructed of basic concrete, main entrance of lead, approaching the radiation bench from the back side. Sound and light signal system connected with dosemeter for showing mini dose of radiation creating conditions for safe work of the dosemeterists. (author) [sr

Characterization of an extrapolation chamber and radiochromic films for verifying the metrological coherence among beta radiation fields

International Nuclear Information System (INIS)

Castillo, Jhonny Antonio Benavente

2011-01-01

The metrological coherence among standard systems is a requirement for assuring the reliability of dosimetric quantities measurements in ionizing radiation field. Scientific and technologic improvements happened in beta radiation metrology with the installment of the new beta secondary standard BSS2 in Brazil and with the adoption of the internationally recommended beta reference radiations. The Dosimeter Calibration Laboratory of the Development Center for Nuclear Technology (LCD/CDTN), in Belo Horizonte, implemented the BSS2 and methodologies are investigated for characterizing the beta radiation fields by determining the field homogeneity, the accuracy and uncertainties in the absorbed dose in air measurements. In this work, a methodology to be used for verifying the metrological coherence among beta radiation fields in standard systems was investigated; an extrapolation chamber and radiochromic films were used and measurements were done in terms of absorbed dose in air. The reliability of both the extrapolation chamber and the radiochromic film was confirmed and their calibrations were done in the LCD/CDTN in 90 Sr/ 90 Y, 85 Kr and 147 Pm beta radiation fields. The angular coefficients of the extrapolation curves were determined with the chamber; the field mapping and homogeneity were obtained from dose profiles and isodose with the radiochromic films. A preliminary comparison between the LCD/CDTN and the Instrument Calibration Laboratory of the Nuclear and Energy Research Institute / Sao Paulo (LCI/IPEN) was carried out. Results with the extrapolation chamber measurements showed in terms of absorbed dose in air rates showed differences between both laboratories up to de -I % e 3%, for 90 Sr/ 90 Y, 85 Kr and 147 Pm beta radiation fields, respectively. Results with the EBT radiochromic films for 0.1, 0.3 and 0.15 Gy absorbed dose in air, for the same beta radiation fields, showed differences up to 3%, -9% and -53%. The beta radiation field mappings with

1. Introduction. 2. Laboratory experiments. 3. Field experiments. 4. Integrated field-laboratory experiments. 5. Panel recommendations

International Nuclear Information System (INIS)

Anon.

1975-01-01

Some recommendations for the design of laboratory and field studies in marine radioecology are formulated. The difficulties concerning the comparability of various experimental methods used to measure the fluxes of radionuclides through marine organisms and ecosystems, and also the use of laboratory results to make predictions for the natural environment are discussed. Three working groups were established during the panel meeting, to consider laboratory experiments, field studies, and the design and execution of integrated laboratory and field studies respectively. A number of supporting papers dealing with marine radioecological experiments were presented

Occupational radiation exposure history of Idaho Field Office Operations at the INEL

International Nuclear Information System (INIS)

Horan, J.R.; Braun, J.B.

1993-10-01

An extensive review has been made of the occupational radiation exposure records of workers at the Idaho National Engineering Laboratory (INEL) over the period of 1951 through 1990. The focus has been on workers employed by contractors and employees of the Idaho Field Operations Office (ID) of the United States Department of Energy (USDOE) and does not include the Naval Reactors Facility (NRF), the Argonne National Laboratory (ANL), or other operations field offices at the INEL. The radiation protection guides have decreased from 15 rem/year to 5 rem/year in 1990 for whole body penetrating radiation exposure. During these 40 years of nuclear operations (in excess of 200,000 man-years of work), a total of twelve individuals involved in four accidents exceeded the annual guidelines for exposure; nine of these exposures were received during life saving efforts on January 3, 1961 following the SL-1 reactor accident which killed three military personnel. These exposures ranged from 8 to 27 rem. Only one individual has exceeded the annual whole body penetrating radiation protection guidelines in the last 29 years

Occupational radiation exposure history of Idaho Field Office Operations at the INEL

Energy Technology Data Exchange (ETDEWEB)

Horan, J.R.; Braun, J.B.

1993-10-01

An extensive review has been made of the occupational radiation exposure records of workers at the Idaho National Engineering Laboratory (INEL) over the period of 1951 through 1990. The focus has been on workers employed by contractors and employees of the Idaho Field Operations Office (ID) of the United States Department of Energy (USDOE) and does not include the Naval Reactors Facility (NRF), the Argonne National Laboratory (ANL), or other operations field offices at the INEL. The radiation protection guides have decreased from 15 rem/year to 5 rem/year in 1990 for whole body penetrating radiation exposure. During these 40 years of nuclear operations (in excess of 200,000 man-years of work), a total of twelve individuals involved in four accidents exceeded the annual guidelines for exposure; nine of these exposures were received during life saving efforts on January 3, 1961 following the SL-1 reactor accident which killed three military personnel. These exposures ranged from 8 to 27 rem. Only one individual has exceeded the annual whole body penetrating radiation protection guidelines in the last 29 years.

Conception of CTMSP ionizing radiation calibration laboratory

International Nuclear Information System (INIS)

Silva, Raimundo Dias da; Kibrit, Eduardo

2009-01-01

The present paper describes the implantation process of an ionizing radiation calibration laboratory in a preexistent installation in CTMSP (bunker) approved by CNEN to operate with gamma-ray for non destructive testing. This laboratory will extend and improve the current metrological capacity for the attendance to the increasing demand for services of calibration of ionizing radiation measuring instruments. Statutory and regulatory requirements for the licensing of the installation are presented and deeply reviewed. (author)

Pyranometer offsets triggered by ambient meteorology: insights from laboratory and field experiments

Science.gov (United States)

Oswald, Sandro M.; Pietsch, Helga; Baumgartner, Dietmar J.; Weihs, Philipp; Rieder, Harald E.

2017-03-01

This study investigates the effects of ambient meteorology on the accuracy of radiation (R) measurements performed with pyranometers contained in various heating and ventilation systems (HV-systems). It focuses particularly on instrument offsets observed following precipitation events. To quantify pyranometer responses to precipitation, a series of controlled laboratory experiments as well as two targeted field campaigns were performed in 2016. The results indicate that precipitation (as simulated by spray tests or observed under ambient conditions) significantly affects the thermal environment of the instruments and thus their stability. Statistical analyses of laboratory experiments showed that precipitation triggers zero offsets of -4 W m-2 or more, independent of the HV-system. Similar offsets were observed in field experiments under ambient environmental conditions, indicating a clear exceedance of BSRN (Baseline Surface Radiation Network) targets following precipitation events. All pyranometers required substantial time to return to their initial signal states after the simulated precipitation events. Therefore, for BSRN-class measurements, the recommendation would be to flag the radiation measurements during a natural precipitation event and 90 min after it in nighttime conditions. Further daytime experiments show pyranometer offsets of 50 W m-2 or more in comparison to the reference system. As they show a substantially faster recovery, the recommendation would be to flag the radiation measurements within a natural precipitation event and 10 min after it in daytime conditions.

Strengthening of an advanced automated radiation laboratory. Hungary. Terminal report project findings and recommendations

International Nuclear Information System (INIS)

1992-01-01

An Advanced Automated Radiation Laboratory was completed; the hardware and software bases are now suitable for up-to-date kinetical measurements in radiation chemistry and technology both for Hungarian experts and for specialists from abroad. It would be possible and useful e.g. to organize further training courses in the field of radiation chemistry and technology by the IAEA and/or the UNDP, as well as to send fellows from developing countries for practical research work or other purposes (TCDC)

Influence of ambient meteorology on the accuracy of radiation measurements: insights from field and laboratory experiments

Science.gov (United States)

Oswald, Sandro M.; Pietsch, Helga; Baumgartner, Dietmar J.; Rieder, Harald E.

2016-04-01

A precise knowledge of the surface energy budget, which includes the solar and terrestrial radiation fluxes, is needed to accurately characterize the global energy balance which is largely determining Earth's climate. To this aim national and global monitoring networks for surface radiative fluxes have been established in recent decades. The most prominent among these networks is the so-called Baseline Surface Radiation Network (BSRN) operating under the auspices of the World Climate Research Programme (WCRP) (Ohmura et al., 1998). National monitoring networks such as the Austrian RADiation Monitoring Network (ARAD), which has been established in 2010 by a consortium of the Central Agency of Meteorology and Geodynamics (ZAMG), the University of Graz, the University of Innsbruck, and the University of Natural Resources and Applied Sciences, Vienna (BOKU), orient themselves on BSRN standards (McArthur, 2005). ARAD comprises to date five sites (Wien Hohe Warte, Graz/University, Innsbruck/University, Kanzelhöhe Observatory and Sonnblick (which is also a BSRN site)) and aims to provide long-term monitoring of radiation budget components at highest accuracy and to capture the spatial patterns of radiation climate in Austria (Olefs et al., 2015). Given the accuracy requirement for the local monitoring of radiative fluxes instrument offsets, triggered by meteorological factors and/or instrumentation, pose a major challenge in radiation monitoring. Within this study we investigate effects of ambient meteorology on the accuracy of radiation measurements performed with pyranometers contained in various heating/ventilation systems (HV-systems), all of which used in regular operation within the ARAD network. We focus particularly on instrument offsets observed following precipitation events. To quantify pyranometer responses to precipitation we performed a series of controlled laboratory experiments as well as targeted field campaigns in 2015 and 2016. Our results indicate

Collimation system for a laboratory of primary and secondary ionizing radiation calibration

International Nuclear Information System (INIS)

Oliveira, S.R.; David, M.G.

2003-01-01

This work is part of a cooperation plan between the LNMRI/IRD and the LCR/UERJ, for the a primary calibration at the IRD and a secondary laboratory at the LCR, both calibrated for mammographic beams which will be part a Calibration National Network. For the mounting of the primary laboratory, the first step was to install two additional collimators in order to guarantee that the beam area over the ionization chamber to satisfy the calibration international standards. So, the collimators were constructed obeying the geometric rules, the first being of conic format and the second of the cylindrical format, therefore avoiding the effects of the scattering radiation on the edges. By using this collimation system it was possible to verify the uniformity of the radiation field incident the ionization chamber to be over 98% of the total area, guaranteeing better precision of the measurement

Pyranometer offsets triggered by ambient meteorology: insights from laboratory and field experiments

OpenAIRE

S. M. Oswald; H. Pietsch; D. J. Baumgartner; P. Weihs; H. E. Rieder

2017-01-01

This study investigates effects of ambient meteorology on the accuracy of radiation measurements performed with pyranometers contained in various heating/ventilation systems (HV-systems). It focuses particularly on instrument offsets observed following precipitation events. To quantify pyranometer responses to precipitation, a series of controlled laboratory experiments as well as two targeted field campaigns were performed in 2016. The results indicate that precipitation (as simulated by spr...

Quality of radiation field imaging

International Nuclear Information System (INIS)

Petr, I.

1988-01-01

The questions were studied of the quality of imaging the gamma radiation field and of the limits of the quality in directional detector scanning. A resolution angle was introduced to quantify the imaging quality, and its relation was sought with the detection effective half-angle of the directional detector. The resolution angle was defined for the simplest configuration of the radiation field consisting of two monoenergetic gamma beams in one plane. It was shown that the resolution angle decreases, i.e., resolution in imaging the radiation field is better, with the effective half-angle of the directional detector. It was also found that resolution of both gamma beams deteriorated when the beams were surrounded with an isotropic background field. If the beams are surrounded with a background field showing general distribution, the angle size will be affected not only by the properties of the detector but also by the distribution of the ambient radiation field and the method of its scanning. The method described can be applied in designing a directional detector necessary for imaging the presumed radiation field in the required quality. (Z.M.). 4 figs., 3 refs

Laboratory training manual on the use of isotopes and radiation in soil-plant relations research

International Nuclear Information System (INIS)

1964-01-01

The International Atomic Energy Agency (IAEA) and the Food and Agriculture Organization of the United Nations (FAO) in co-operation with local authorities in various countries have jointly sponsored international laboratory training courses on the use of isotopes and radiation in specialized fields of agriculture. Outstanding scientists from various countries have given lectures and devised and conducted the laboratory exercises; research workers from all over the world have attended these courses. In addition, under the United Nations Expanded Programme of Technical Assistance the IAEA in co-operation with host governments has conducted similar regional courses. This laboratory manual is a natural outgrowth of these activities. The contents represents the efforts not only of the IAEA and FAO Secretariats but also of the various instructors who have participated in the courses, a Special Consultant, Victor Middelboe, and a panel of scientists who met in Vienna from 3 to 7 September 1962 and revised the initial version assembled by Hans Broeshart and Chai Moo Cho of the IAEA Secretariat. The present manual consists of two parts: a basic part which contains general information and laboratory exercises on the properties of radiation and the principles of use of radioactive tracers, and a second part which contains a series of detailed laboratory exercises in the field of soil-plant relationships. It is intended to publish at least four additional parts on the subjects of the use of isotopes and radiation in animal science, agricultural biochemistry, entomology and plant pathology. This manual, dealing with an important aspect of the peaceful application and use of atomic energy, should prove helpful not only to those working with the IAEA and FAO training programmes but to other research scientists dealing with the development and use of new information in agricultural science all over the world

Radiation tolerance in the fruit fly, Drosophila Melanogaster - effects of laboratory culturing and stages in life cycle

International Nuclear Information System (INIS)

Vas, Iril Prima; Naik, Pramila; Kumar, Vineeth; Naik, Prathima; Patil, Rajashekar K.

2013-01-01

Radiation induced damages are due to direct effect of radiation energy or through free radical generation. Recent studies suggest Drosophila to be a good animal model to study radiation tolerance. The present study on female Drosophila melanogaster was conducted to observe 1. Variations in larval and adult radiation tolerance 2. Variations in laboratory culture and field populations of Drosophila. Third instar larvae were exposed to gamma radiation of 6, 10, 20, 30, 40 and 50 Gy in gamma chamber GC 5000 (BRT, India). Larvae of flies collected from the field were reared for two generations in the lab before irradiation. The laboratory cultured files were from stocks that were maintained for more than 1000 generations. The larvae of field populations had higher survival rate at 51% as compared to 43% in case of cultured flies and thus more resistant. The III instar larval stage (lab culture) had a LD50 of 26 Gy as compared to LD 50 of 928 Gy in case of adult flies have ∼ 160 times higher tolerance compared to humans. Prolonged rearing comparable to 'domestication' might have induced reduction in tolerance. Larval stages have a lower tolerance than adults possibly due to higher metabolic rate. Adults are post-mitotic in nature with very low rate of cell division. This may contribute to higher tolerance. This however is in contradiction to studies of midge (Chironomous) where larvae also have higher tolerance. (author)

Test and evaluation of semiconductor components in mixed field radiation monitoring

International Nuclear Information System (INIS)

Cardenas, Jose Patricio N.; Madi Filho, Tufic; Rodrigues, Leticia L.C.

2009-01-01

Silicon components have found extensive use in nuclear spectroscopy and counting, as described in many articles in the last three decades. These devices have found utility in radiation dosimetry because a diode, for instance, produces a current approximately 18000 times higher than any ionization chamber of equal sensitive volume. This reduces stringent requirements from the electronics used to amplify or integrate the current and / or allows approaching the ideal detector point for the mapping of radiation fields. For better performance, in the case of diodes, they are normally used with high inverse polarity to obtain a deeper barrier, less noise and shorter transit time. The aim of this work was the evaluation of these semiconductor components for application in ionizing radiation fields monitoring, in nuclear research reactors and radiotherapy facilities, for radiation protection and health physics purposes. Experimental configurations to analyze the performance of commercial semiconductors, such as silicon PIN Photodiodes and Silicon Surface Barrier Detectors, were developed and the performance of three different configurations of charge preamplifier with silicon components was also studied. Components were evaluated for application as neutron detectors, using some types of radiators (converters). The radiation response of these silicon components to neutron fields from nuclear research reactors IEA-R1 and IPEN-MB1 (thermal, epithermal and fast neutrons), from beam holes, experimental halls and AmBe neutron sources in laboratory was investigated. (author)

Radiation detectors laboratory; Laboratorio de detectores de radiacion

Energy Technology Data Exchange (ETDEWEB)

Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

1997-07-01

The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

Electric field deformation in diamond sensors induced by radiation defects

Energy Technology Data Exchange (ETDEWEB)

Kassel, Florian; Boer, Wim de; Boegelspacher, Felix; Dierlamm, Alexander; Mueller, Thomas; Steck, Pia [Institut fuer Experimentelle Kernphysik (IEKP), Karlsruher Institut fuer Technologie (KIT) (Germany); Dabrowski, Anne; Guthoff, Moritz [CERN (Switzerland)

2016-07-01

The BCML system is a beam monitoring device in the CMS experiment at the LHC. As detectors 32 poly-crystalline CVD diamond sensors are positioned in a ring around the beam pipe at a distance of ±1.8 m and ±14.4 m from the interaction point. The radiation hardness of the diamond sensors in terms of measured signal during operation was significantly lower than expected from laboratory measurements. At high particle rates, such as those occurring during the operation of the LHC, a significant fraction of the defects act as traps for charge carriers. This space charge modifies the electrical field in the sensor bulk leading to a reduction of the charge collection efficiency (CCE). A diamond irradiation campaign was started to investigate the rate dependent electrical field deformation with respect to the radiation damage. Besides the electrical field measurements via the Transient Current Technique, the CCE was measured. The experimental results were used to create an effective trap model that takes the radiation damage into account. Using this trap model the rate dependent electrical field deformation and the CCE were simulated with the software ''SILVACO TCAD''. This talk compares the experimental measurement results with the simulations.

Scaling plant ultraviolet spectral responses from laboratory action spectra to field spectral weighting factors

International Nuclear Information System (INIS)

Flint, S.D.; Caldwell, M.M.

1996-01-01

Biological spectral weighting functions (BSWF) play a key role in calculating the increase of biologically effective solar ultraviolet-B radiation (UV-BBE) due to ozone reduction, assessing current latitudinal gradients of UV-B BE . and comparing solar UV-B BE with that from lamps and filters in plant experiments. Plant UV action spectra (usually determined with monochromatic radiation in the laboratory with exposure periods on the order of hours) are often used as BSWF. The realism of such spectra for plants growing day after day in polychromatic solar radiation in the field is questionable. We tested the widely used generalized plant action spectrum since preliminary data from an action spectrum being developed with monochromatic radiation for a cultivated oat variety indicate reasonable agreement with the generalized spectrum. These tests involved exposing plants to polychromatic radiation either from a high-pressure xenon arc lamp in growth chambers or in the field under solar radiation with supplemental UV-B lamps. Different broad-spectrum combinations were achieved by truncating the spectrum at successively longer UV wavelengths with various filters. In the growth chamber experiments, the generalized plant spectrum appeared to predict plant growth responses at short (<310nm) wavelengths but not at longer wavelengths. The field experiment reinforced these conclusions, showing (in addition to the expected direct UV-B effects) both direct UV-A effects and UV-A mitigation of UV-B effects. (author)

Radiation protection calibration facilities at the National Radiation Laboratory, New Zealand

International Nuclear Information System (INIS)

Foote, B.J.

1995-01-01

The National Radiation Laboratory (NRL), serving under the Ministry of Health, provides radiation protection services to the whole of New Zealand. Consequently it performs many functions that are otherwise spread amongst several organizations in larger countries. It is the national regulatory body for radiation protection. It writes and enforces codes of safe practice, and conducts safety inspections of all workplaces using radiation. It provides a personal monitoring service for radiation workers. It also maintains the national primary standards for x-ray exposure and 60 Co air kerma. These standards are transferred to hospitals through a calibration service. The purpose of this report is to outline the primary standards facilities at NRL, and to discuss the calibration of dosemeters using these facilities. (J.P.N.)

National Laboratory of Ionizing Radiation Metrology - Brazilian CNEN

International Nuclear Information System (INIS)

1992-01-01

The activities of the Brazilian National Laboratory of Ionizing Radiations Metrology are described. They include research and development of metrological techniques and procedures, the calibration of area radiation monitors, clinical dosemeters and other instruments and the preparation and standardization of reference radioactive sources. 4 figs., 13 tabs

National High Magnetic Field Laboratory (NHMFL)

Data.gov (United States)

Federal Laboratory Consortium — The Pulsed Field Program is located in Northern New Mexico at Los Alamos National Laboratory. The user program is designed to provide researchers with a balance of...

Radiation safety. Handbook for laboratory workers in the USA

International Nuclear Information System (INIS)

Hotte, E.D.; Krueger, D.J.; Connor, K.

2000-01-01

The aim of the Handbook is to provide a source of information on radiation safety for those who are involved in the use of ionizing radiation in the laboratory. The potential reader may be a laboratory worker in the university or biomedical setting or the safety professional who desires a basic understanding of radiation protection within the research environment. The Handbook may be used as a reference by the radiation protection specialist or Radiation Safety Officer. To this end, liberal use is made of Appendices to make the Handbook a source of reference for a wide spectrum of readership while avoiding complicating the main body of the text. Each chapter or appendix is designed to stand alone. A complete reading of the Handbook will show that topics may be covered more than once. For example, one may read about the hazards and protective measures on handling radioiodine in Chapter 5 on Practical Radiation Protection as well as in Appendix 19 on Safe Handling of 125 I. Extensive use of figures, rather than tables has been made to present data, in the belief that these produce a good visual representation to a level of precision which is sufficient for most purposes of radiation protection in laboratories. The reader must remember that this Handbook should be taken as a guide only to the applicable regulations. You must consult the appropriate state or federal regulation directly or receive advice of a qualified radiation safety professional. Also, some information in the Appendices, such as commercially available training institutions or radioactive waste brokers, may change with time. Telephone numbers are given for the reader to call directly and check the services provided

The New High Magnetic Field Laboratory at Dresden: a Pulsed-Field Laboratory at an IR Free-Electron-Laser

International Nuclear Information System (INIS)

Pobell, F.; Bianchi, A. D.; Herrmannsdoerfer, T.; Krug, H.; Zherlitsyn, S.; Zvyagin, S.; Wosnitza, J.

2006-01-01

We report on the construction of a new high magnetic field user laboratory which will offer pulsed-field coils in the range (60 T, 500 ms, 40 mm) to (100 T, 10 ms, 20 mm) for maximum field, pulse time, and bore diameter of the coils. These coils will be energized by a modular 50 MJ/24 kV capacitor bank. Besides many other experimental techniques, as unique possibilities NMR in pulsed fields as well as infrared spectroscopy at 5 to 150 μm will be available by connecting the pulsed field laboratory to a nearby free-electron-laser facility

Hydrogen Field Test Standard: Laboratory and Field Performance

Science.gov (United States)

Pope, Jodie G.; Wright, John D.

2015-01-01

The National Institute of Standards and Technology (NIST) developed a prototype field test standard (FTS) that incorporates three test methods that could be used by state weights and measures inspectors to periodically verify the accuracy of retail hydrogen dispensers, much as gasoline dispensers are tested today. The three field test methods are: 1) gravimetric, 2) Pressure, Volume, Temperature (PVT), and 3) master meter. The FTS was tested in NIST's Transient Flow Facility with helium gas and in the field at a hydrogen dispenser location. All three methods agree within 0.57 % and 1.53 % for all test drafts of helium gas in the laboratory setting and of hydrogen gas in the field, respectively. The time required to perform six test drafts is similar for all three methods, ranging from 6 h for the gravimetric and master meter methods to 8 h for the PVT method. The laboratory tests show that 1) it is critical to wait for thermal equilibrium to achieve density measurements in the FTS that meet the desired uncertainty requirements for the PVT and master meter methods; in general, we found a wait time of 20 minutes introduces errors methods, respectively and 2) buoyancy corrections are important for the lowest uncertainty gravimetric measurements. The field tests show that sensor drift can become a largest component of uncertainty that is not present in the laboratory setting. The scale was calibrated after it was set up at the field location. Checks of the calibration throughout testing showed drift of 0.031 %. Calibration of the master meter and the pressure sensors prior to travel to the field location and upon return showed significant drifts in their calibrations; 0.14 % and up to 1.7 %, respectively. This highlights the need for better sensor selection and/or more robust sensor testing prior to putting into field service. All three test methods are capable of being successfully performed in the field and give equivalent answers if proper sensors without drift are

Design and implementation of a virtual laboratory of radiation measurement

International Nuclear Information System (INIS)

Alvarez T, J. R.; Morales S, J. B.

2009-10-01

The work involves the implementation of a virtual laboratory, this project is conducted in the Faculty of Engineering of National Autonomous University of Mexico with the name of LANUVI. It is intended that the laboratory can be used by students who have interest in the nuclear radiation knowledge as well as in its detection and attenuation, in addition serve as and introduction to nuclear systems. In the first part of project will conduct a source that can simulate the particle radiation of Alfa, beta, neutrons and gamma rays. The project will take sources used in class laboratories and elements that are dangerous but are used in different practical applications. After taking the source analyzing the particles behaviour in different media like air, animal tissue, aluminium, lead, etc. The analysis is done in different ways in order to know with which material can stop or mitigate the different types of radiation. Finally shall be measure radioactivity with different types of detectors. At this point, has the behaviour of ionization chamber but in the future is expected to make the simulation of some other radiation detectors. The mathematical models we represent the behaviour of these cases were implemented in free software. The program will be used to implement the virtual laboratory with radiation sources, detectors and different types of shields will be Blender which is a free software that is used by many users for the embodiment of games but try to use as a tool to help visualize the different equipment that is widely used in a radioactive materials laboratory. (Author)

Standardization of reference radiation field of beta for 85Kr using extrapolation chamber

International Nuclear Information System (INIS)

Nazaroh; Fendinugroho

2013-01-01

Standardization of reference radiation field of beta for 85 Kr in PTKMR-BATAN Laboratory has been performed at the SDD's 30 cm by using extrapolation chamber detector, coupled with Uni dose electrometer. The result was : (8.98±3 %) mGy/h, at 95 % confidence level. The aim of standardization of reference radiation field is to support radiation protection and safety program, provided by the International Atomic Energy Agency to its Member States, included BATAN-Indonesia, especially, PTKMR. The aim of radiation protection program and safety program is to promote an internationally harmonized approach for radiation measurement in protection level, besides for calibration of radiation measuring instrument, which users spread across Indonesia, with the number of about 795 firms in the year of 2012. These benefits can be felt by workers, communities and the environment, because by calibration, measurement survey meter, pocket dosimeter and TLD to be more accurate so that the radiation dose received by radiation workers is accurate and can be ascertained in a specified period, not to exceed a predetermined NBD by BAPETEN. The aim of this calibration is appropriate with the primary objective of calibration on IAEA/TRS16:2000. (author)

Reference radiation fields - Simulated workplace neutron fields - Part 2: Calibration fundamentals related to the basic quantities

International Nuclear Information System (INIS)

2008-01-01

ISO 8529-1, ISO 8529-2 and ISO 8529-3, deal with the production, characterization and use of neutron fields for the calibration of personal dosimeters and area survey meters. These International Standards describe reference radiations with neutron energy spectra that are well defined and well suited for use in the calibration laboratory. However, the neutron spectra commonly encountered in routine radiation protection situations are, in many cases, quite different from those produced by the sources specified in the International Standards. Since personal neutron dosimeters, and to a lesser extent survey meters, are generally quite energy dependent in their dose equivalent response, it might not be possible to achieve an appropriate calibration for a device that is used in a workplace where the neutron energy spectrum and angular distribution differ significantly from those of the reference radiation used for calibration. ISO 8529-1 describes four radionuclide based neutron reference radiations in detail. This part of ISO 12789 includes the specification of neutron reference radiations that were developed to closely resemble radiation that is encountered in practice

International intercomparison of environmental dosimeters under field and laboratory conditions

International Nuclear Information System (INIS)

Gesell, T.F.; de Planque Burke, G.; Becker, K.

1975-04-01

Based on the results of a pilot study at ORNL in 1973, a more comprehensive international intercomparison of integrating dosimeters for the assessment of external penetrating environmental radiation fields was carried out. Forty-one laboratories from eleven countries participated in this study. A total of 56 sets of six detectors each were mailed to and from Houston, Texas, where they were exposed for three months (July to September 1974) as follows: two in an unprotected space out-of-doors 1 m above ground; two in an air-conditioned shielded area with a known, low exposure rate; and two with the second group, but with an additional exposure to 30 mR. Evaluation of the dosimeters provides information on the calibration precision, the accuracy of field measurement, and transit exposure. Results are discussed. (U.S.)

Secondary standards laboratories for ionizing radiation calibrations: the national laboratory interests

International Nuclear Information System (INIS)

Roberson, P.L.; Campbell, G.W.

1984-11-01

The national laboratories are probable candidates to serve as secondary standards laboratories for the federal sector. Representatives of the major Department of Energy laboratories were polled concerning attitudes toward a secondary laboratory structure. Generally, the need for secondary laboratories was recognized and the development of such a program was encouraged. The secondary laboratories should be reviewed and inspected by the National Bureau of Standards. They should offer all of the essential, and preferably additional, calibration services in the field of radiological health protection. The selection of secondary laboratories should be based on economic and geographic criteria and/or be voluntary. 1 ref., 2 tabs

Data survey about radiation protection and safety of radiation sources in research laboratories

International Nuclear Information System (INIS)

Paura, Clayton L.; Dantas, Ana Leticia A.; Dantas, Bernardo M.

2005-01-01

In Brazil, different types of research using unsealed sources are developed with a variety of radioisotopes. In such activities, professionals and students involved are potentially exposed to internal contamination by 14 C, 45 Ca, 51 Cr, 3 H, 125 I, 32 P, 33 P, 35 S, 90 Sr and 99m Tc. The general objective of this work is to evaluate radiological risks associated to these practices in order to supply information for planning actions aimed to improve radiation protection conditions in research laboratories. The criteria for risk evaluation and the safety aspects adopted in this work were based on CNEN Regulation 6.02 and in IAEA and NRPB publications. The survey of data was carried out during visits to laboratories in public Universities located in the city of Rio de Janeiro where unsealed radioactive sources are used in biochemistry, biophysics and genetic studies. According to the criteria adopted in this work, some practices developed in the laboratories require evaluation of risk of internal contamination depending on the conditions of source manipulation. It was verified the need for training of users of radioactive materials in this type of laboratory. This can be facilitated by the use of basic guides for the classification of areas, radiation protection, safety and source security in research laboratories. It was also observed the need for optimization of such practices in order to minimize the contact with sources. It is recommended to implement more effective source and access controls as a way to reduce risks of individual radiation exposure and loss of radioactive materials (author)

Practice for characterization and performance of a high-dose radiation dosimetry calibration laboratory

International Nuclear Information System (INIS)

2003-01-01

This practice addresses the specific requirements for laboratories engaged in dosimetry calibrations involving ionizing radiation, namely, gamma-radiation, electron beams or X-radiation (bremsstrahlung) beams. It specifically describes the requirements for the characterization and performance criteria to be met by a high-dose radiation dosimetry calibration laboratory. The absorbed-dose range is typically between 10 and 10 5 Gy. This practice addresses criteria for laboratories seeking accreditation for performing high-dose dosimetry calibrations, and is a supplement to the general requirements described in ISO/IEC 17025. By meeting these criteria and those in ISO/IEC 17025, the laboratory may be accredited by a recognized accreditation organization. Adherence to these criteria will help to ensure high standards of performance and instill confidence regarding the competency of the accredited laboratory with respect to the services it offers

LAWRENCE RADIATION LABORATORY COUNTING HANDBOOK

Energy Technology Data Exchange (ETDEWEB)

Group, Nuclear Instrumentation

1966-10-01

The Counting Handbook is a compilation of operational techniques and performance specifications on counting equipment in use at the Lawrence Radiation Laboratory, Berkeley. Counting notes have been written from the viewpoint of the user rather than that of the designer or maintenance man. The only maintenance instructions that have been included are those that can easily be performed by the experimenter to assure that the equipment is operating properly.

Astrophysical radiative shocks: From modeling to laboratory experiments

Czech Academy of Sciences Publication Activity Database

Gonzales, N.; Stehlé, C.; Audit, E.; Busquet, M.; Rus, Bedřich; Thais, F.; Acef, O.; Barroso, P.; Bar-Shalom, A.; Bauduin, D.; Kozlová, Michaela; Lery, T.; Madouri, A.; Mocek, Tomáš; Polan, Jiří

2006-01-01

Roč. 24, - (2006), s. 535-540 ISSN 0263-0346 EU Projects: European Commission(XE) 506350 - LASERLAB-EUROPE; European Commission(XE) 5592 - JETSET Grant - others:CNRS(FR) PNPS Institutional research plan: CEZ:AV0Z10100523 Keywords : laboratory astrophysics * laser plasmas * radiative shock waves * radiative transfer Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.958, year: 2006

Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

Energy Technology Data Exchange (ETDEWEB)

Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: psouza@cnen.gov.br, e-mail: jodinilson@cnen.gov.br; Calixto, Merilane S.; Santos, Neide [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Genetica

2009-07-01

Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources {sup 241}AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

International Nuclear Information System (INIS)

Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

2009-01-01

Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

Construction and operation of an improved radiation calibration facility at Brookhaven National Laboratory. Environmental assessment

International Nuclear Information System (INIS)

1994-10-01

Calibration of instruments used to detect and measure ionizing radiation has been conducted over the last 20 years at Brookhaven National Laboratory's (BNL) Radiation Calibration Facility, Building 348. Growth of research facilities, projects in progress, and more stringent Department of Energy (DOE) orders which involve exposure to nuclear radiation have placed substantial burdens on the existing radiation calibration facility. The facility currently does not meet the requirements of DOE Order 5480.4 or American National Standards Institute (ANSI) N323-1978, which establish calibration methods for portable radiation protection instruments used in the detection and measurement of levels of ionizing radiation fields or levels of radioactive surface contaminations. Failure to comply with this standard could mean instrumentation is not being calibrated to necessary levels of sensitivity. The Laboratory has also recently obtained a new neutron source and gamma beam irradiator which can not be made operational at existing facilities because of geometry and shielding inadequacies. These sources are needed to perform routine periodic calibrations of radiation detecting instruments used by scientific and technical personnel and to meet BNL's substantial increase in demand for radiation monitoring capabilities. To place these new sources into operation, it is proposed to construct an addition to the existing radiation calibration facility that would house all calibration sources and bring BNL calibration activities into compliance with DOE and ANSI standards. The purpose of this assessment is to identify potential significant environmental impacts associated with the construction and operation of an improved radiation calibration facility at BNL

A Radiation Laboratory Curriculum Development at Western Kentucky University

International Nuclear Information System (INIS)

Barzilov, Alexander P.; Novikov, Ivan S.; Womble, Phil C.

2009-01-01

We present the latest developments for the radiation laboratory curriculum at the Department of Physics and Astronomy of Western Kentucky University. During the last decade, the Applied Physics Institute (API) at WKU accumulated various equipment for radiation experimentation. This includes various neutron sources (computer controlled d-t and d-d neutron generators, and isotopic 252 Cf and PuBe sources), the set of gamma sources with various intensities, gamma detectors with various energy resolutions (NaI, BGO, GSO, LaBr and HPGe) and the 2.5-MeV Van de Graaff particle accelerator. XRF and XRD apparatuses are also available for students and members at the API. This equipment is currently used in numerous scientific and teaching activities. Members of the API also developed a set of laboratory activities for undergraduate students taking classes from the physics curriculum (Nuclear Physics, Atomic Physics, and Radiation Biophysics). Our goal is to develop a set of radiation laboratories, which will strengthen the curriculum of physics, chemistry, geology, biology, and environmental science at WKU. The teaching and research activities are integrated into real-world projects and hands-on activities to engage students. The proposed experiments and their relevance to the modern status of physical science are discussed.

Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

International Nuclear Information System (INIS)

Reynaldo, S. R.; Benavente C, J. A.; Da Silva, T. A.

2015-10-01

Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the 90 Sr/ 90 Y and 85 Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the 90 Sr/ 90 Y and -0.3% for the 85 Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

Light source for synchrotron radiation x-ray topography study at Beijing Synchrotron Radiation Laboratory (BSRL)

International Nuclear Information System (INIS)

Zhao Jiyong; Jiang Jianhua; Tian Yulian

1992-01-01

Characteristics of the synchrotron radiation source for X-ray topography study at Beijing Synchrotron Radiation Laboratory (BSRL) is described, local geometrical resolution of topographies is discussed, and the diffracting intensities of white beam topography is given

Solar Radiation Research Laboratory | Energy Systems Integration Facility |

Science.gov (United States)

Solar Radiation Research Laboratory (SRRL) has been collecting continuous measurements of basic solar continuous operation. More than 75 instruments contribute to the Baseline Measurement System by recording

Radiation field distribution within the room for three commonly-used interventional procedures

International Nuclear Information System (INIS)

Liu Changcai; Zhang Lin; Min Nan; Lu Feng; Li Quantai; Deng Daping; Chen Yue; Zhu Jianguo

2014-01-01

Objective: To detect the radiation field distribution within the room for three commonly-used interventional procedures, in order to provide basic data for the radiation protection and safe operation of staff involved in interventional radiology. Methods: The thermoluminescent dosemeters (TLDs) were placed in different points on the horizontal plane around the interventional table and the vertical plane where the staff often stayed. Based on the selected experimental conditions, the TLDs were grouped to be irradiated. After the experiment, the TLDs were measured in the laboratory to calculate the doses of radiation field. Results: Data obtained at the same position followed basically as cardiovascular intervention > cerebrovascular intervention > liver intervention. Intervention of same type at the same position followed as high-dose group > mid-dose group > low-dose group. These results were consistent with the useful beam doses, and proportional to the fluoroscopy time. A few data with exception were due to measurement error or experimental error. Conclusions: Cerebrovascular and liver interventional procedures resulted in the relatively low radiation doses. The radiation doses at the distance of more than 3 m can be negligible. For cardiovascular interventional procedure, with the decrease of the distance from the X-ray tube, the dose decreased. In the radiation field,the operator, the first assistant and second assistant would exposed to higher dose on the standing points while patients receive lower doses in the head and feet direction. (authors)

Workplace photon radiation fields

International Nuclear Information System (INIS)

Burgess, P.H.; Bartlett, D.T.; Ambrosi, P.

1999-01-01

The knowledge of workplace radiation fields is essential for measures in radiation protection. Information about the energy and directional distribution of the incident photon radiation was obtained by several devices developed by the National Radiation Protection Board, United Kingdom, by the Statens Stralskyddsinstitut, Sweden, together with EURADOS and by the Physikalisch-Technische Bundesanstalt, Germany. The devices are described and some results obtained at workplaces in nuclear industry, medicine and science in the photon energy range from 20 keV to 7 MeV are given. (author)

Thirty-sixth Lauriston S. Taylor Lecture on radiation protection and measurements--from the field to the laboratory and back: the what ifs, wows, and who cares of radiation biology.

Science.gov (United States)

Brooks, Antone L

2013-11-01

My scientific journey started at the University of Utah chasing fallout. It was on everything, in everything, and was distributed throughout the ecosystem. This resulted in radiation doses to humans and caused me great concern. From this concern I asked the question, "Are there health effects from these radiation doses and levels of radioactive contamination?" I have invested my scientific career trying to address this basic question. While conducting research, I got acquainted with many of the What ifs of radiation biology. The major What if in my research was, "What if we have underestimated the radiation risk for internally-deposited radioactive material?" While conducting research to address this important question, many other What ifs came up related to dose, dose rate, and dose distribution. I also encountered a large number of Wows. One of the first was when I went from conducting environmental fallout studies to research in a controlled laboratory. The activity in fallout was expressed as pCi L⁻¹, whereas it was necessary to inject laboratory animals with μCi g⁻¹ body weight to induce measurable biological changes, chromosome aberrations, and cancer. Wow! That is seven to nine orders of magnitude above the activity levels found in the environment. Other Wows have made it necessary for the field of radiation biology to make important paradigm shifts. For example, one shift involved changing from "hit theory" to total tissue responses as the result of bystander effects. Finally, Who cares? While working at U.S. Department of Energy headquarters and serving on many scientific committees, I found that science does not drive regulatory and funding decisions. Public perception and politics seem to be major driving forces. If scientific data suggested that risk had been underestimated, everyone cared. When science suggested that risk had been overestimated, no one cared. This result-dependent Who cares? was demonstrated as we tried to generate interactions

Gravitational radiation resistance, radiation damping and field fluctuations

International Nuclear Information System (INIS)

Schaefer, G.

1981-01-01

Application is made of two different generalised fluctuation-dissipation theorems and their derivations to the calculation of the gravitational quadrupole radiation resistance using the radiation-reaction force given by Misner, Thorne and Wheeler (Gravitation (San Francisco: Freeman) ch 36,37 (1973)) and the usual tidal force on one hand and the tidal force and the free gravitational radiation field on the other hand. The quantum-mechanical version (including thermal generalisations) of the well known classical quadrupole radiation damping formula is obtained as a function of the radiation resistance. (author)

Savannah River Plant/Savannah River Laboratory radiation exposure report

International Nuclear Information System (INIS)

Rogers, C.D.; Hyman, S.D.; Keisler, L.L.; Reeder, D.F.; Jolly, L.; Spoerner, M.T.; Schramm, G.R.

1989-01-01

The protection of worker health and safety is of paramount concern at the Savannah River Site. Since the site is one of the largest nuclear sites in the nation, radiation safety is a key element in the protection program. This report is a compendium of the results in 1988 of the programs at the Savannah River Plant and the Savannah River Laboratory to protect the radiological health of employees. By any measure, the radiation protection performance at this site in 1988 was the best since the beginning of operations. This accomplishment was made possible by the commitment and support at all levels of the organizations to reduce radiation exposures to ALARA (As Low As Reasonably Achievable). The report provides detailed information about the radiation doses received by departments and work groups within these organizations. It also includes exposure data for recent years to allow Plant and Laboratory units to track the effectiveness of their ALARA efforts. Many of the successful practices and methods that reduced radiation exposure are described. A new goal for personnel contamination cases has been established for 1989. Only through continual and innovative efforts to minimize exposures can the goals be met. The radiation protection goals for 1989 and previous years are included in the report. 27 figs., 58 tabs

Establishment of exposure dose assessment laboratory in National Radiation Emergency Medical Center (NREMC)

Energy Technology Data Exchange (ETDEWEB)

Yoo, Jae Ryong; Ha, Wi Ho; Yoon, Seok Won; Han, Eun Ae; Lee, Seung Sook [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2011-10-15

As unclear industry grown, 432 of the nuclear power plants are operating and 52 of NPPs are under construction currently. Increasing use of radiation or radioisotopes in the field of industry, medical purpose and research such as non-destructive examination, computed tomography and x-ray, etc. constantly. With use of nuclear or radiation has incidence possibility for example the Fukushima NPP incident, the Goiania accident and the Chernobyl Nuclear accident. Also the risk of terror by radioactive material such as Radiological Dispersal Device(RDD) etc. In Korea, since the 'Law on protection of nuclear facilities and countermeasure for radioactive preparedness was enacted in 2003, the Korean institute of Radiological and Medical Sciences(KIRAMS) was established for the radiation emergency medical response in radiological disaster due to nuclear accident, radioactive terror and so on. Especially National Radiation Emergency Medical Center(NREMC) has the duty that is protect citizens from nuclear, radiological accidents or radiological terrors through the emergency medical preparedness. The NREMC was established by the 39-article law on physical protection of nuclear material and facilities and measures for radiological emergencies. Dose assessment or contamination survey should be performed which provide the radiological information for medical response. For this reason, the NREMC establish and re-organized dose assessment system based on the existing dose assessment system of the NREMC recently. The exposure dose could be measured by physical and biological method. With these two methods, we can have conservative dose assessment result. Therefore the NREMC established the exposure dose assessment laboratory which was re-organized laboratory space and introduced specialized equipment for dose assessment. This paper will report the establishment and operation of exposure dose assessment laboratory for radiological emergency response and discuss how to enhance

Calibration of radioprotection equipment gamma radiation at the Laboratory of Ionizing Radiation Metrology - DEN/UFPE

International Nuclear Information System (INIS)

Nazario, Macilene; Khoury, Helen; Hazin, Clovis

2003-01-01

This work presents aspects of the radioprotection equipment calibration service of the Laboratory for Metrology of Ionizing Radiations (LMRI) of the DEN/UFPE related to the calibration procedures, characteristics of the radiation beam and the evaluation of equipment calibrated in the period of 2001-2002. The LMRI-DEN/UFPE is one of the four laboratories in Brazil licensed by the Brazilian Nuclear Energy Commission for the execution of calibration services on area, surface contamination and personal monitors used by industries, hospitals, universities and research institutes using radioactive sources

Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

Energy Technology Data Exchange (ETDEWEB)

Reynaldo, S. R. [Development Centre of Nuclear Technology, Posgraduate Course in Science and Technology of Radiations, Minerals and Materials / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Benavente C, J. A.; Da Silva, T. A., E-mail: sirr@cdtn.br [Development Centre of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

2015-10-15

Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the {sup 90}Sr/{sup 90}Y and {sup 85}Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the {sup 90}Sr/{sup 90}Y and -0.3% for the {sup 85}Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

Graphene Field Effect Transistor for Radiation Detection

Science.gov (United States)

Li, Mary J. (Inventor); Chen, Zhihong (Inventor)

2016-01-01

The present invention relates to a graphene field effect transistor-based radiation sensor for use in a variety of radiation detection applications, including manned spaceflight missions. The sensing mechanism of the radiation sensor is based on the high sensitivity of graphene in the local change of electric field that can result from the interaction of ionizing radiation with a gated undoped silicon absorber serving as the supporting substrate in the graphene field effect transistor. The radiation sensor has low power and high sensitivity, a flexible structure, and a wide temperature range, and can be used in a variety of applications, particularly in space missions for human exploration.

Standardization of irradiation values at the Radiation Calibration Laboratory

International Nuclear Information System (INIS)

Pham Van Dung; Hoang Van Nguyen; Phan Van Toan; Phan Dinh Sinh; Tran Thi Tuyet; Do Thi Phuong

2007-01-01

The objective of the theme is to determine dose rates around radiation facilities and sources in the NRI Radiation Calibration Laboratory. By improving equipment, calibrating a main dosemeter and carrying out experiments, the theme team received the following results: 1. The controller of a X-rays generator PY(-200 was improved. It permits to increase accuracy of radiation dose calibration up to 2-4 times; 2. The FAMER DOSEMETER 2570/1B with the ionization chamber NE 2575 C of the NRI Radiation Calibration Laboratory was calibrated at SSDL (Hanoi); 3. Dose rates at 4 positions around a high activity Co-60 source were determined; 4. Dose rates at 3 positions around a low activity Co-60 source were determined; 5. Dose rates at 3 positions around a low activity Cs-137 source were determined; 6. Dose rate at 1 position of a X-rays beam (Eaverage = 48 keV) was determined; 7. Dose rate at 1 position of a X-rays beam (Eaverage = 65 keV) was determined. (author)

Annual report of the Osaka Laboratory for Radiation Chemistry, Japan Atomic Energy Research Institute (No. 8)

International Nuclear Information System (INIS)

1975-10-01

This report describes research activities in Osaka Laboratory for Radiation Chemistry, JAERI during the one year period from April 1, 1974 through March 31, 1975. The major research field covers the following subjects: studies related to reactions of carbon monoxide and hydrogen; polymerization studies under the irradiation of high dose rate electron beams; modification of polymers; fundamental studies on polymerization, degradation, crosslinking, and grafting. (auth.)

Practical radiation protection for radiography

International Nuclear Information System (INIS)

Hubbard, S.K.; Proudfoot, E.A.

1978-01-01

Nondestructive Testing Applications and Radiological Engineering at the Hanford Engineering Development Laboratory have developed radiation protection procedures, radiation work procedures, and safe practice procedures to assure safe operation for all radiographic work. The following topics are discussed: training in radiation safety; radiation exposure due to operations at Hanford; safeguards employed in laboratory radiography; field radiographic operations; and problems

Galactic cosmic ray simulation at the NASA Space Radiation Laboratory

Science.gov (United States)

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

2017-01-01

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

Occupational radiation exposures in research laboratories

International Nuclear Information System (INIS)

Vaccari, S.; Papotti, E.; Pedrazzi, G.

2006-01-01

Radioactive sources are widely used in many research activities at University centers. In particular, the activities concerning use of sealed form ( 57 Co in Moessbauer application) and unsealed form ( 3 H, 14 C, 32 P in radioisotope laboratories) are analyzed. The radiological impact of these materials and potential effective doses to researchers and members of the public were evaluated to show compliance with regulatory limits. A review of the procedures performed by researchers and technicians in the research laboratories with the relative dose evaluations is presented in different situations, including normal operations and emergency situations, for example the fire. A study of the possible exposure to radiation by workers, restricted groups of people, and public in general, as well as environmental releases, is presented. (authors)

Secondary calibration laboratory for ionizing radiation laboratory accreitation program National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program

Energy Technology Data Exchange (ETDEWEB)

Martin, P.R.

1993-12-31

This paper presents an overview of the procedures and requirements for accreditation under the Secondary Calibration Laboratory for Ionizing Radiation Program (SCLIR LAP). The requirements for a quality system, proficiency testing and the onsite assessment are discussed. The purpose of the accreditation program is to establish a network of secondary calibration laboratories that can provide calibrations traceable to the primary national standards.

Secondary calibration laboratory for ionizing radiation laboratory accreitation program National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program

International Nuclear Information System (INIS)

Martin, P.R.

1993-01-01

This paper presents an overview of the procedures and requirements for accreditation under the Secondary Calibration Laboratory for Ionizing Radiation Program (SCLIR LAP). The requirements for a quality system, proficiency testing and the onsite assessment are discussed. The purpose of the accreditation program is to establish a network of secondary calibration laboratories that can provide calibrations traceable to the primary national standards

Radiation Entropy and Near-Field Thermophotovoltaics

Science.gov (United States)

Zhang, Zhuomin M.

2008-08-01

Radiation entropy was key to the original derivation of Planck's law of blackbody radiation, in 1900. This discovery opened the door to quantum mechanical theory and Planck was awarded the Nobel Prize in Physics in 1918. Thermal radiation plays an important role in incandescent lamps, solar energy utilization, temperature measurements, materials processing, remote sensing for astronomy and space exploration, combustion and furnace design, food processing, cryogenic engineering, as well as numerous agricultural, health, and military applications. While Planck's law has been fruitfully applied to a large number of engineering problems for over 100 years, questions have been raised about its limitation in micro/nano systems, especially at subwavelength distances or in the near field. When two objects are located closer than the characteristic wavelength, wave interference and photon tunneling occurs that can result in significant enhancement of the radiative transfer. Recent studies have shown that the near-field effects can realize emerging technologies, such as superlens, sub-wavelength light source, polariton-assisted nanolithography, thermophotovoltaic (TPV) systems, scanning tunneling thermal microscopy, etc. The concept of entropy has also been applied to explain laser cooling of solids as well as the second law efficiency of devices that utilize thermal radiation to produce electricity. However, little is known as regards the nature of entropy in near-field radiation. Some history and recent advances are reviewed in this presentation with a call for research of radiation entropy in the near field, due to the important applications in the optimization of thermophotovoltaic converters and in the design of practical systems that can harvest photon energies efficiently.

Quality assurance in field radiation measurements

International Nuclear Information System (INIS)

Howell, W.P.

1985-01-01

In most cases, an ion chamber radiation measuring instrument is calibrated in a uniform gamma radiation field. This results in a uniform ionization field throughout the ion chamber. Measurement conditions encountered in the field often produce non-uniform ionization fields within the ion chamber, making determination of true dose rates to personnel difficult and prone to error. Extensive studies performed at Hanford have provided appropriate correction factors for use with one type of ion chamber instrument, the CP. Suitable corrections are available for the following distinct measurement circumstances: (1) contact measurements on large beta and gamma sources, (2) contact measurements on small beta and gamma sources, (3) contact measurements on small-diameter cylinders, (4) measurements in small gamma beams, and (5) measurements at a distance from large beta sources. Recommendations are made for the implementation of these correction factors, in the interest of improved quality assurance in field radiation measurements. 12 references, 10 figures

Vacuum radiation induced by time dependent electric field

Directory of Open Access Journals (Sweden)

Bo Zhang

2017-04-01

Full Text Available Many predictions of new phenomena given by strong field quantum electrodynamics (SFQED will be tested on next generation multi-petawatt laser facilities in the near future. These new phenomena are basis to understand physics in extremely strong electromagnetic fields therefore have attracted wide research interest. Here we discuss a new SFQED phenomenon that is named as vacuum radiation. In vacuum radiation, a virtual electron loop obtain energy from time dependent external electric field and radiate an entangled photon pair. Features of vacuum radiation in a locally time dependent electric field including spectrum, characteristic temperature, production rate and power are given.

Vacuum radiation induced by time dependent electric field

Energy Technology Data Exchange (ETDEWEB)

Zhang, Bo, E-mail: zhangbolfrc@caep.cn [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Zhang, Zhi-meng; Hong, Wei; He, Shu-Kai; Teng, Jian [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Gu, Yu-qiu, E-mail: yqgu@caep.cn [Department of High Energy Density Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China); Laboratory of Science and Technology on Plasma Physics, Research Center of Laser Fusion, 621900, Mianyang, Sichuan (China)

2017-04-10

Many predictions of new phenomena given by strong field quantum electrodynamics (SFQED) will be tested on next generation multi-petawatt laser facilities in the near future. These new phenomena are basis to understand physics in extremely strong electromagnetic fields therefore have attracted wide research interest. Here we discuss a new SFQED phenomenon that is named as vacuum radiation. In vacuum radiation, a virtual electron loop obtain energy from time dependent external electric field and radiate an entangled photon pair. Features of vacuum radiation in a locally time dependent electric field including spectrum, characteristic temperature, production rate and power are given.

Sample tracking in an automated cytogenetic biodosimetry laboratory for radiation mass casualties

International Nuclear Information System (INIS)

Martin, P.R.; Berdychevski, R.E.; Subramanian, U.; Blakely, W.F.; Prasanna, P.G.S.

2007-01-01

Chromosome-aberration-based dicentric assay is expected to be used after mass-casualty life-threatening radiation exposures to assess radiation dose to individuals. This will require processing of a large number of samples for individual dose assessment and clinical triage to aid treatment decisions. We have established an automated, high-throughput, cytogenetic biodosimetry laboratory to process a large number of samples for conducting the dicentric assay using peripheral blood from exposed individuals according to internationally accepted laboratory protocols (i.e., within days following radiation exposures). The components of an automated cytogenetic biodosimetry laboratory include blood collection kits for sample shipment, a cell viability analyzer, a robotic liquid handler, an automated metaphase harvester, a metaphase spreader, high-throughput slide stainer and coverslipper, a high-throughput metaphase finder, multiple satellite chromosome-aberration analysis systems, and a computerized sample-tracking system. Laboratory automation using commercially available, off-the-shelf technologies, customized technology integration, and implementation of a laboratory information management system (LIMS) for cytogenetic analysis will significantly increase throughput. This paper focuses on our efforts to eliminate data-transcription errors, increase efficiency, and maintain samples' positive chain-of-custody by sample tracking during sample processing and data analysis. This sample-tracking system represents a 'beta' version, which can be modeled elsewhere in a cytogenetic biodosimetry laboratory, and includes a customized LIMS with a central server, personal computer workstations, barcode printers, fixed station and wireless hand-held devices to scan barcodes at various critical steps, and data transmission over a private intra-laboratory computer network. Our studies will improve diagnostic biodosimetry response, aid confirmation of clinical triage, and medical

Sample tracking in an automated cytogenetic biodosimetry laboratory for radiation mass casualties

Energy Technology Data Exchange (ETDEWEB)

Martin, P.R.; Berdychevski, R.E.; Subramanian, U.; Blakely, W.F. [Armed Forces Radiobiology Research Institute, Uniformed Services University of Health Sciences, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States); Prasanna, P.G.S. [Armed Forces Radiobiology Research Institute, Uniformed Services University of Health Sciences, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States)], E-mail: prasanna@afrri.usuhs.mil

2007-07-15

Chromosome-aberration-based dicentric assay is expected to be used after mass-casualty life-threatening radiation exposures to assess radiation dose to individuals. This will require processing of a large number of samples for individual dose assessment and clinical triage to aid treatment decisions. We have established an automated, high-throughput, cytogenetic biodosimetry laboratory to process a large number of samples for conducting the dicentric assay using peripheral blood from exposed individuals according to internationally accepted laboratory protocols (i.e., within days following radiation exposures). The components of an automated cytogenetic biodosimetry laboratory include blood collection kits for sample shipment, a cell viability analyzer, a robotic liquid handler, an automated metaphase harvester, a metaphase spreader, high-throughput slide stainer and coverslipper, a high-throughput metaphase finder, multiple satellite chromosome-aberration analysis systems, and a computerized sample-tracking system. Laboratory automation using commercially available, off-the-shelf technologies, customized technology integration, and implementation of a laboratory information management system (LIMS) for cytogenetic analysis will significantly increase throughput. This paper focuses on our efforts to eliminate data-transcription errors, increase efficiency, and maintain samples' positive chain-of-custody by sample tracking during sample processing and data analysis. This sample-tracking system represents a 'beta' version, which can be modeled elsewhere in a cytogenetic biodosimetry laboratory, and includes a customized LIMS with a central server, personal computer workstations, barcode printers, fixed station and wireless hand-held devices to scan barcodes at various critical steps, and data transmission over a private intra-laboratory computer network. Our studies will improve diagnostic biodosimetry response, aid confirmation of clinical triage, and

Determination of the scattered radiation at the Neutron Calibration Laboratory of IPEN, SP, Brazil

International Nuclear Information System (INIS)

Alvarenga, Tallyson; Valeriano, Caio C.S.; Caldas, Linda V.E.; Federico, Claudio A.

2016-01-01

With the increased use of techniques using neutron radiation, there has been a considerable growth in the number of detectors for this kind of radiation. A neutron calibration laboratory with neutron radiation ("2"4"1AmBe) was designed. In practical situations of this type of laboratory, one of the main problems is related to the knowledge of scattered radiation. In order to evaluate this scattered radiation, simulations were carried out without the presence of structural elements and with the complete room. Fourteen measuring points were evaluated in different directions at various distances. (author)

Super-Planckian far-field radiative heat transfer

Science.gov (United States)

Fernández-Hurtado, V.; Fernández-Domínguez, A. I.; Feist, J.; García-Vidal, F. J.; Cuevas, J. C.

2018-01-01

We present here a theoretical analysis that demonstrates that the far-field radiative heat transfer between objects with dimensions smaller than the thermal wavelength can overcome the Planckian limit by orders of magnitude. To guide the search for super-Planckian far-field radiative heat transfer, we make use of the theory of fluctuational electrodynamics and derive a relation between the far-field radiative heat transfer and the directional absorption efficiency of the objects involved. Guided by this relation, and making use of state-of-the-art numerical simulations, we show that the far-field radiative heat transfer between highly anisotropic objects can largely overcome the black-body limit when some of their dimensions are smaller than the thermal wavelength. In particular, we illustrate this phenomenon in the case of suspended pads made of polar dielectrics like SiN or SiO2. These structures are widely used to measure the thermal transport through nanowires and low-dimensional systems and can be employed to test our predictions. Our work illustrates the dramatic failure of the classical theory to predict the far-field radiative heat transfer between micro- and nanodevices.

Occupational radiation exposures in research laboratories

Energy Technology Data Exchange (ETDEWEB)

Vaccari, S.; Papotti, E. [Parma Univ., Health Physics (Italy); Pedrazzi, G. [Parma Univ., Dept. of Public Health (Italy)

2006-07-01

Radioactive sources are widely used in many research activities at University centers. In particular, the activities concerning use of sealed form ({sup 57}Co in Moessbauer application) and unsealed form ({sup 3}H, {sup 14}C, {sup 32}P in radioisotope laboratories) are analyzed. The radiological impact of these materials and potential effective doses to researchers and members of the public were evaluated to show compliance with regulatory limits. A review of the procedures performed by researchers and technicians in the research laboratories with the relative dose evaluations is presented in different situations, including normal operations and emergency situations, for example the fire. A study of the possible exposure to radiation by workers, restricted groups of people, and public in general, as well as environmental releases, is presented. (authors)

Ambient radiation levels in a microPET/CT research laboratory

Energy Technology Data Exchange (ETDEWEB)

Sarmento, D.M.; Rodrigues, D.L.; Sanches, M.P.; Carneiro, J.C.G.G., E-mail: janetegc@ipen.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

This study focuses on initial radiological evaluation and the exposure situation related to the worker task in a micro-positron emission tomography/computed tomography laboratory (microPET/CT). Selected and calibrated thermoluminescent dosimeters, TLD, of CaSO{sub 4}:Dy were used to measure room radiation levels. The detectors were placed in several selected points inside the microPET/CT laboratory and adjacent rooms. In addition, the occupationally exposed workers were monthly evaluated for external and internal exposures. In none of the selected points the dose values exceeded the radiation dose limit established for supervised area, as well as the values obtained in individual monitoring. (author)

Ambient radiation levels in a microPET/CT research laboratory

International Nuclear Information System (INIS)

Sarmento, D.M.; Rodrigues, D.L.; Sanches, M.P.; Carneiro, J.C.G.G.

2015-01-01

This study focuses on initial radiological evaluation and the exposure situation related to the worker task in a micro-positron emission tomography/computed tomography laboratory (microPET/CT). Selected and calibrated thermoluminescent dosimeters, TLD, of CaSO 4 :Dy were used to measure room radiation levels. The detectors were placed in several selected points inside the microPET/CT laboratory and adjacent rooms. In addition, the occupationally exposed workers were monthly evaluated for external and internal exposures. In none of the selected points the dose values exceeded the radiation dose limit established for supervised area, as well as the values obtained in individual monitoring. (author)

Experimental microdosimetry in high energy radiation fields

International Nuclear Information System (INIS)

Spurny, F.; Bednar, J.; Vlcek, B.; Bottollier-Depois, J.-F.; Molokanov, A.G.

2000-01-01

correspond to the interactions of secondary panicles created by primary radiation are close to the sensitive volume of the equipment. The comparison of both methods was performed in the field on board aircraft and in high energy reference fields. it was found that the microdosimetric distributions observed agreed at least qualitatively, a quantitative agreement of integral dosimetric values was found as well. The measurements in proton beams were performed in several points along the Bragg curve. Actually, we were able to observe the influence of primary beam contamination due to the filtration as well as due to the secondary particle created during the penetration of beams in the phantome. The relevance of such data for the radiotherapy application of high energy protons is evident. It was proved that both method can give relevant and useful information on the microdosimetric distributions in complex beams and fields of high energy panicles. The further development of this approach is in progress in our laboratories. (author)

Participation of the radiation hygiene laboratories to the WHO/UNEP global environmental radiation network

International Nuclear Information System (INIS)

Milu, C.; Gheorghe, R.

2003-01-01

In December 1987, a WHO-UNEP meeting held at SCPRI (Service Central de protection canter Les Rayonnements Ionisantes - Le Vesinet, France) set up the basis of the international network GERMON (Global Environmental Radiation Monitoring Network) as an extension of existing network 'Global Environment Monitoring Systems' (GEMS). The accident from Chernobyl certainly was the important nuclear event influencing this decision. The aim of the GERMON network is to initiate programmes for the routine monitoring of the environmental radioactivity and to ensure a quick interchange of credible data in case of major accidental radioactive releases, as well as the development of intervention devices in the member states running such programmes. The responsibility of the Co-ordinating Collaborating Centre (CCC) has been given to the French Service Central de Protection Centre les Rayonnements Ionisants (SCPRI). In 1994, this Service became the Office de Protection Centre les Rayonnements Ionisants (OPRI). The Ministry of Health has a national network consisting of 23 radiation hygiene laboratories; 19 of these are included in the framework of county divisions of public health , and the other 4 are compartments of the regional institutes of public health. WHO designated the Institute of Public Health from Bucharest as National Contact Centre, in charge with communicating the results obtained by the national laboratories on the indicators of environmental radioactivity, according to the established methodologies. The main indicators considered are: ambient gamma dose, radioactivity of the air, of the precipitation, and of the milk. Following the measurement and transmission protocols of the CCC, the Radiation Hygiene Laboratory from the Institute of Public Health has established a methodology to be followed by the laboratories of the national network. (authors)

Role of secondary standard dosimetry laboratory in radiation protection program

International Nuclear Information System (INIS)

Rahman, Sohaila; Ali, Noriah Mohd.

2008-01-01

Full text: The radiation dosimetry program is an important element of operational radiation protection. Dosimetry data enable workers and radiation protection professionals to evaluate and control work practices to eliminate unnecessary exposure to ionizing radiation. The usefulness of the data produced however depends on its quality and traceability. The emphasis of the global dosimetry program is focused through the IAEA/WHO network of secondary standard dosimetry laboratories (SSDLs), which aims for the determination of SI quantities through proper traceable calibration of radiation protection equipment. The responsibility of SSDL-NUCLEAR MALAYSIA to guarantee a reliable dosimetry service, which is traceable to international standards, is elucidated. It acts as the basis for harmonized occupational radiation monitoring in Malaysia.

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...

On quantization of the electromagnetic field in radiation gauge

International Nuclear Information System (INIS)

Burzynski, A.

1982-01-01

This paper contains a detailed description of quantization of the electromagnetic field (in radiation gauge) and quantization of some basic physical variables connected with radiation field as energy, momentum and spin. The dynamics of the free quantum radiation field and the field interacting with external classical sources is described. The canonical formalism is not used explicity. (author)

PREFACE: Acceleration and radiation generation in space and laboratory plasmas

Science.gov (United States)

Bingham, R.; Katsouleas, T.; Dawson, J. M.; Stenflo, L.

1994-01-01

and radiation generation in plasmas. The next section includes state-of-the-art papers on laboratory accelerators driven by lasers (Nakajima et al., Shukla, Johnson et al.), microwaves (Nishida et al., Bogomolov et al.) and by particle beams (Ogata et al.). Also in this section are theoretical papers presenting new work on synchrotron like oscillations in plasma waves (Fedele) and two types of laboratory radiation sources, FEL's (Marshall et al.) and ionization fronts (Lai et al.), and Frantzeskakis et al. described the Hamiltonian analysis of a slow-wave autonomous cyclotron buncher. Section 3 contains papers on astrophysical plasmas, with the general presentations of Colgate and Krishnan. Kazanas and Krishnan address active galactic nuclei (AGNs). Thielheim discusses general acceleration mech anisms in rotating magnetized systems. Asseo discussed Langmuir solitons in pulsars and Blackman et al. treat magnetic reconnection relativistically. Su et al. analyze the possibility of plasma wave excitation and particle acceleration by neu trinos from supernovae. Dogiel et al. on cosmic ray scattering by MHD fluctuations. The papers in Section 4 treat fusion plasmas (Dendy et al. and Lashmore-Davies et al.). Section 5, space plasmas, includes papers on acceleration processes in the magnetosphere (Anagnostopoulos and Marshall et al.) and the sun (Barletta et al.). It is evident from the Workshop and the papers collected here that this is indeed a rich field of investigations and that both the natural and laboratory plasma communities can benefit from the cross-fertilization of ideas between them. We wish to thank the authors and attendees for their contributions to the success of this workshop, Dr Philip Debenham and Dr David Sutter of the U.S. D.o.E. and Dr Charles Roberson of the U.S. O.N.R. for their financial support (Grants DE-FGO3-93ER40776 and N00014-93-1-0814), and the ECC Twinning Grant SC1*-CT92-0773. We appreciate the considerable local support from Mr Glegles and

Experimental determination of radiated internal wave power without pressure field data

Science.gov (United States)

Lee, Frank M.; Paoletti, M. S.; Swinney, Harry L.; Morrison, P. J.

2014-04-01

We present a method to determine, using only velocity field data, the time-averaged energy flux left and total radiated power P for two-dimensional internal gravity waves. Both left and P are determined from expressions involving only a scalar function, the stream function ψ. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data.

Experimental determination of radiated internal wave power without pressure field data

International Nuclear Information System (INIS)

Lee, Frank M.; Morrison, P. J.; Paoletti, M. S.; Swinney, Harry L.

2014-01-01

We present a method to determine, using only velocity field data, the time-averaged energy flux (J) and total radiated power P for two-dimensional internal gravity waves. Both (J) and P are determined from expressions involving only a scalar function, the stream function ψ. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data

Radiation field mapping using a mechanical-electronic detector

Energy Technology Data Exchange (ETDEWEB)

Czayka, M., E-mail: mczayka@kent.ed [College of Technology, Kent State University-Ashtabula 3300 Lake Road West, Ashtabula, OH 44004 (United States); Program on Electron Beam Technology, Kent State University, P.O. Box 1028, Middlefield, OH 44062 (United States); Fisch, M. [Program on Electron Beam Technology, Kent State University, P.O. Box 1028, Middlefield, OH 44062 (United States); College of Technology, Kent State University, P.O. Box 5190, Kent, OH 44242-0001 (United States)

2010-04-15

A method of radiation field mapping of a scanned electron beam using a Faraday-type detector and an electromechanical linear translator is presented. Utilizing this arrangement, fluence and fluence rate measurements can be made at different locations within the radiation field. The Faraday-type detector used in these experiments differs from most as it consists of a hollow stainless steel sphere. Results are presented in two- and three-dimensional views of the radiation field.

Environmental surveillance program of the Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Thomas, R.H.

1976-04-01

The major radiological environmental impact of the Lawrence Berkeley Laboratory is due to the operation of four particle accelerators. Potential sources of population exposure at the Laboratory are discussed. The major source of population exposure due to accelerator operation arises from the prompt radiation field which consists principally of neutrons and photons. Release of small quantities of radionuclides is also a potential source of population exposure but is usually an order of magnitude less significant. Accelerator produced radiation levels at the Laboratory boundary are comparable with the magnitudes of the fluctuations found in the natural background radiation. Environmental monitoring of accelerator-produced radiation and of radionuclides is carried on throughout the Laboratory, at the Laboratory perimeter, and in the regions surrounding the Laboratory. The techniques used are described. The models used to calculate population exposure are described and discussed

Fruit Flies Provide New Insights in Low-Radiation Background Biology at the INFN Underground Gran Sasso National Laboratory (LNGS).

Science.gov (United States)

Morciano, Patrizia; Cipressa, Francesca; Porrazzo, Antonella; Esposito, Giuseppe; Tabocchini, Maria Antonella; Cenci, Giovanni

2018-06-04

Deep underground laboratories (DULs) were originally created to host particle, astroparticle or nuclear physics experiments requiring a low-background environment with vastly reduced levels of cosmic-ray particle interference. More recently, the range of science projects requiring an underground experiment site has greatly expanded, thus leading to the recognition of DULs as truly multidisciplinary science sites that host important studies in several fields, including geology, geophysics, climate and environmental sciences, technology/instrumentation development and biology. So far, underground biology experiments are ongoing or planned in a few of the currently operating DULs. Among these DULs is the Gran Sasso National Laboratory (LNGS), where the majority of radiobiological data have been collected. Here we provide a summary of the current scenario of DULs around the world, as well as the specific features of the LNGS and a summary of the results we obtained so far, together with other findings collected in different underground laboratories. In particular, we focus on the recent results from our studies of Drosophila melanogaster, which provide the first evidence of the influence of the radiation environment on life span, fertility and response to genotoxic stress at the organism level. Given the increasing interest in this field and the establishment of new projects, it is possible that in the near future more DULs will serve as sites of radiobiology experiments, thus providing further relevant biological information at extremely low-dose-rate radiation. Underground experiments can be nicely complemented with above-ground studies at increasing dose rate. A systematic study performed in different exposure scenarios provides a potential opportunity to address important radiation protection questions, such as the dose/dose-rate relationship for cancer and non-cancer risk, the possible existence of dose/dose-rate threshold(s) for different biological systems and

A method for characterizing photon radiation fields

International Nuclear Information System (INIS)

Whicker, J.J.; Hsu, H.H.; Hsieh, F.H.; Borak, T.B.

1999-01-01

Uncertainty in dosimetric and exposure rate measurements can increase in areas where multi-directional and low-energy photons (< 100 keV) exist because of variations in energy and angular measurement response. Also, accurate measurement of external exposures in spatially non-uniform fields may require multiple dosimetry. Therefore, knowledge of the photon fields in the workplace is required for full understanding of the accuracy of dosimeters and instruments, and for determining the need for multiple dosimeters. This project was designed to develop methods to characterize photon radiation fields in the workplace, and to test the methods in a plutonium facility. The photon field at selected work locations was characterized using TLDs and a collimated NaI(Tl) detector from which spatial variations in photon energy distributions were calculated from measured spectra. Laboratory results showed the accuracy and utility of the method. Field measurement results combined with observed work patterns suggested the following: (1) workers are exposed from all directions, but not isotropically, (2) photon energy distributions were directionally dependent, (3) stuffing nearby gloves into the glovebox reduced exposure rates significantly, (4) dosimeter placement on the front of the chest provided for a reasonable estimate of the average dose equivalent to workers' torsos, (5) justifiable conclusions regarding the need for multiple dosimetry can be made using this quantitative method, and (6) measurements of the exposure rates with ionization chambers pointed with open beta windows toward the glovebox provided the highest measured rates, although absolute accuracy of the field measurements still needs to be assessed

Image noise reduction technology reduces radiation in a radial-first cardiac catheterization laboratory

Energy Technology Data Exchange (ETDEWEB)

Gunja, Ateka; Pandey, Yagya [Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL (United States); Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, IL (United States); Xie, Hui [Division of Epidemiology and Biostatistics, University of Illinois at Chicago, Chicago, IL (United States); Faculty of Health Sciences, Simon Fraser University, Burnaby, BC (Canada); Wolska, Beata M. [Department of Physiology and Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL (United States); Shroff, Adhir R.; Ardati, Amer K. [Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL (United States); Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, IL (United States); Vidovich, Mladen I., E-mail: miv@uic.edu [Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL (United States); Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, IL (United States)

2017-04-15

Background: Transradial coronary angiography (TRA) has been associated with increased radiation doses. We hypothesized that contemporary image noise reduction technology would reduce radiation doses in the cardiac catheterization laboratory in a typical clinical setting. Methods and results: We performed a single-center, retrospective analysis of 400 consecutive patients who underwent diagnostic and interventional cardiac catheterizations in a predominantly TRA laboratory with traditional fluoroscopy (N = 200) and a new image noise reduction fluoroscopy system (N = 200). The primary endpoint was radiation dose (mGy cm{sup 2}). Secondary endpoints were contrast dose, fluoroscopy times, number of cineangiograms, and radiation dose by operator between the two study periods. Radiation was reduced by 44.7% between the old and new cardiac catheterization laboratory (75.8 mGy cm{sup 2} ± 74.0 vs. 41.9 mGy cm{sup 2} ± 40.7, p < 0.0001). Radiation was reduced for both diagnostic procedures (45.9%, p < 0.0001) and interventional procedures (37.7%, p < 0.0001). There was no statistically significant difference in radiation dose between individual operators (p = 0.84). In multivariate analysis, radiation dose remained significantly decreased with the use of the new system (p < 0.0001) and was associated with weight (p < 0.0001), previous coronary artery bypass grafting (p < 0.0007) and greater than 3 stents used (p < 0.0004). TRA was used in 90% of all cases in both periods. Compared with a transfemoral approach (TFA), TRA was not associated with higher radiation doses (p = 0.20). Conclusions: Image noise reduction technology significantly reduces radiation dose in a contemporary radial-first cardiac catheterization clinical practice. - Highlights: • Radial arterial access has been associated with higher doses compared to femoral access. • In a radial-first cardiac catheterization laboratory (90% radial) we examined radiation doses reduction with a contemporary image

Image noise reduction technology reduces radiation in a radial-first cardiac catheterization laboratory

International Nuclear Information System (INIS)

Gunja, Ateka; Pandey, Yagya; Xie, Hui; Wolska, Beata M.; Shroff, Adhir R.; Ardati, Amer K.; Vidovich, Mladen I.

2017-01-01

Background: Transradial coronary angiography (TRA) has been associated with increased radiation doses. We hypothesized that contemporary image noise reduction technology would reduce radiation doses in the cardiac catheterization laboratory in a typical clinical setting. Methods and results: We performed a single-center, retrospective analysis of 400 consecutive patients who underwent diagnostic and interventional cardiac catheterizations in a predominantly TRA laboratory with traditional fluoroscopy (N = 200) and a new image noise reduction fluoroscopy system (N = 200). The primary endpoint was radiation dose (mGy cm"2). Secondary endpoints were contrast dose, fluoroscopy times, number of cineangiograms, and radiation dose by operator between the two study periods. Radiation was reduced by 44.7% between the old and new cardiac catheterization laboratory (75.8 mGy cm"2 ± 74.0 vs. 41.9 mGy cm"2 ± 40.7, p < 0.0001). Radiation was reduced for both diagnostic procedures (45.9%, p < 0.0001) and interventional procedures (37.7%, p < 0.0001). There was no statistically significant difference in radiation dose between individual operators (p = 0.84). In multivariate analysis, radiation dose remained significantly decreased with the use of the new system (p < 0.0001) and was associated with weight (p < 0.0001), previous coronary artery bypass grafting (p < 0.0007) and greater than 3 stents used (p < 0.0004). TRA was used in 90% of all cases in both periods. Compared with a transfemoral approach (TFA), TRA was not associated with higher radiation doses (p = 0.20). Conclusions: Image noise reduction technology significantly reduces radiation dose in a contemporary radial-first cardiac catheterization clinical practice. - Highlights: • Radial arterial access has been associated with higher doses compared to femoral access. • In a radial-first cardiac catheterization laboratory (90% radial) we examined radiation doses reduction with a contemporary image-noise compared to

Synchrotron radiation laboratories at the Bonn electron accelerators. a status report

Science.gov (United States)

Hormes, J.

1987-07-01

At the Physikalisches Institut of the University in Bonn experiments with synchrotron radiation were carried out ever since 1962. At the moment (June 1986) all work takes place in the SR-laboratory at the 2.5 GeV synchrotron. A 3.5 GeV stretcher ring (ELSA) is under construction and will come into operation at the end of 1986. This accelerator will also run as a storage ring for synchrotron radiation experiments and a laboratory to be used at this machine is also under consideration. The SR experiments which are carried out in Bonn try to take advantage of the fact that we are still using a high energy synchrotron for our work. Besides basic research also applied work is done using synchrotron radiation even as a production tool for X-ray lithography.

X radiation qualities characterization following the standard IEC 61267 recommendations at the calibration laboratory of IPEN

International Nuclear Information System (INIS)

Franciscatto, Priscila Cerutti

2009-01-01

This work presents a methodology for the X radiation qualities characterization following the new recommendations of the standard 61267 of the International Electrotechnical Commission (IEC) to establish a new procedure for calibration of dosimetric systems used in the field of diagnostic radiology. The reference qualities radiation of IEC 61267: RQR 2 to RQR 10, RQA 2 to RQA 10, RQB 2 to RQB 10 and RQN 2 to RQN 10 were implanted at the calibration laboratory of IPEN (LCI). Their characteristics were analyzed through measurements of beam parameters such as: Practical peak voltage (PPV), specific additional filtrations for each qualities (high purity aluminum of about 99.9%), 1st and 2nd Half Value Layers, homogeneity coefficient. The inherent filtration of the X ray tube was also determined. With the establishment of these radiation qualities, the LCI will be ready to calibrate the measuring instruments of radiation in the new qualities, allowing an improvement in radiological services offered by IPEN. (author)

Air kerma national standard of Russian Federation for x-ray and gamma radiation. Activity SSDL/VNIIM in medical radiation dosimetry field

International Nuclear Information System (INIS)

Kharitonov, I.A.; Villevalde, N.D.; Oborin, A.V.; Fominykh, V.I.

2002-01-01

for medium-energy X-ray range in 1998. The results of comparisons are presented in the table 1. Dimensions of unities of air kerma and air kerma rate are transmitted from primary standard to secondary standards with expanded uncertainty from 1,3 to 2,5 % (k=2), which are including and at laboratory SSDL/VNIIM and base dosimetry laboratory CNIRRI. The comparisons of secondary standards with the primary standard VNIIM are performed one time in 5 years. The laboratory SSDL/VNIIM is the component of state primary standards laboratory in the field of measurement ionizing radiations VNIIM. SSDL/VNIIM has the secondary standard - universal dosimeter UNIDOS with ionization chambers of volume from 0,6 cm 3 to 10 liters, radioactive sources from Fe-55, Cd-109, Am-241, Cs-137 and Co-60 with activity from 0,03 to 140 GBq. The primary standard equipment and facility on the basis industrial X-ray apparatus YRD-1 with a tungsten-anode X-ray tube and inherent filtration of around 3 mm Al (at generating potential from 50 to 250 kV) are used for calibration dosimetric devices in the field X-ray. There is termoluminescence dosimetric system such as KDT-02M with TL detectors from LiF for spending audit measurements by method 'dose-post'. Laboratory SSDL/VNIIM and base dosimetric laboratory CNIRRI are carried out calibrations and verifications of air kerma and air kerma rate reference standards and working measurement means for X-ray and gamma therapy and diagnostics, belonging to the oncology and diagnostic centers, clinics and hospitals. The laboratory CNIRRI fulfils the verification of measurement means and supervision of the application in the medical radiology, but the regional departments of radial diagnostics put into practice monitoring of doses, obtained by patients and staff at fulfilling of diagnostic and medical procedures. The diagnostic and clinical dosimeters are calibrated directly under the primary standard of air kerma and air kerma rate for achievement the highest

Performance of neutron and gamma personnel dosimetry in mixed radiation fields

International Nuclear Information System (INIS)

Swaja, R.E.; Sims, C.S.

1981-01-01

From 1974 to 1980, six personnel dosimetry intercomparison studies (PDIS) were conducted at the Oak Ridge National Laboratory (ORNL) to evaluate the performance of personnel dosimeters in a variety of neutron and gamma fields produced by operating the Health Physics Research Reactor (HPRR) in the steady state mode with and without spectral modifying shields. A total of 58 different organizations participated in these studies which produced approximately 2000 measurements of neutron and gamma dose equivalents on anthropomorphic phantoms for five different reactor spectra. Based on these data, the relative performance of three basic types of neutron dosimeters [nuclear emulsion film, thermoluminescent (TLD), and track-etch] and two basic types of gamma dosimeters (film and TLD) in mixed radiation fields was assessed

Separation of radiation from two sources from their known radiated sum field

DEFF Research Database (Denmark)

Laitinen, Tommi; Pivnenko, Sergey

2011-01-01

This paper presents a technique for complete and exact separation of the radiated fields of two sources (at the same frequency) from the knowledge of their radiated sum field. The two sources can be arbitrary but it must be possible to enclose the sources inside their own non-intersecting minimum...

Size-dependent reactivity of magnetite nanoparticles: a field-laboratory comparison

Science.gov (United States)

Swindle, Andrew L.; Elwood Madden, Andrew S.; Cozzarelli, Isabelle M.; Benamara, Mourad

2014-01-01

Logistic challenges make direct comparisons between laboratory- and field-based investigations into the size-dependent reactivity of nanomaterials difficult. This investigation sought to compare the size-dependent reactivity of nanoparticles in a field setting to a laboratory analog using the specific example of magnetite dissolution. Synthetic magnetite nanoparticles of three size intervals, ∼6 nm, ∼44 nm, and ∼90 nm were emplaced in the subsurface of the USGS research site at the Norman Landfill for up to 30 days using custom-made subsurface nanoparticle holders. Laboratory analog dissolution experiments were conducted using synthetic groundwater. Reaction products were analyzed via TEM and SEM and compared to initial particle characterizations. Field results indicated that an organic coating developed on the particle surfaces largely inhibiting reactivity. Limited dissolution occurred, with the amount of dissolution decreasing as particle size decreased. Conversely, the laboratory analogs without organics revealed greater dissolution of the smaller particles. These results showed that the presence of dissolved organics led to a nearly complete reversal in the size-dependent reactivity trends displayed between the field and laboratory experiments indicating that size-dependent trends observed in laboratory investigations may not be relevant in organic-rich natural systems.

Radiation of an electron in an electric field. 1

International Nuclear Information System (INIS)

Fedosov, N.I.; Flesher, G.I.

1976-01-01

The problem of electron radiation in a field of a travelling electric wave is solved by methods of classical electrodynamics. Such a field may serve as a model of a field on the linear accelerator axis. It is shown that the total radiation power, as well as the spectral-angular distribution of the radiation energy of an electron travelling in a longitudinal electric wave coincide with radiation in a stationary uniform electric field with the strength equal to that of the wave at the point where the particle velocity becomes close to the velocity of light [ru

Predicting bioremediation of hydrocarbons: Laboratory to field scale

International Nuclear Information System (INIS)

Diplock, E.E.; Mardlin, D.P.; Killham, K.S.; Paton, G.I.

2009-01-01

There are strong drivers to increasingly adopt bioremediation as an effective technique for risk reduction of hydrocarbon impacted soils. Researchers often rely solely on chemical data to assess bioremediation efficiently, without making use of the numerous biological techniques for assessing microbial performance. Where used, laboratory experiments must be effectively extrapolated to the field scale. The aim of this research was to test laboratory derived data and move to the field scale. In this research, the remediation of over thirty hydrocarbon sites was studied in the laboratory using a range of analytical techniques. At elevated concentrations, the rate of degradation was best described by respiration and the total hydrocarbon concentration in soil. The number of bacterial degraders and heterotrophs as well as quantification of the bioavailable fraction allowed an estimation of how bioremediation would progress. The response of microbial biosensors proved a useful predictor of bioremediation in the absence of other microbial data. Field-scale trials on average took three times as long to reach the same endpoint as the laboratory trial. It is essential that practitioners justify the nature and frequency of sampling when managing remediation projects and estimations can be made using laboratory derived data. The value of bioremediation will be realised when those that practice the technology can offer transparent lines of evidence to explain their decisions. - Detailed biological, chemical and physical characterisation reduces uncertainty in predicting bioremediation.

Toward a direct comparison of field and laboratory goniometer measurements

NARCIS (Netherlands)

Dangel, S.; Verstraete, M.; Schopfer, J.; Kneubuehler, M.; Schaepman, M.E.; Itten, K.I.

2005-01-01

Field and laboratory goniometers are widely used in the remote sensing community to assess spectrodirectional reflection properties of selected targets. Even when the same target and goniometer system are used, field and laboratory results cannot directly be compared due to inherent differences,

The calibration method for personal dosimetry system in photon and neutron radiation fields

Energy Technology Data Exchange (ETDEWEB)

Trousil, J; Plichta, J [CSOD, Prague (Czech Republic); Nikodemova, D [SOD, Bratislava (Slovakia)

1996-12-31

The type testing of dosimetry system was performed with standard photon radiation fields within the energy range 15 keV to 1.25 MeV and electron radiation fields within the range 0.2 MeV to 3 MeV. For type testing of neutron dosimeters {sup 252}Cf and {sup 241}Am-Be radionuclide neutron sources was used, as well as a 14 MeV neutron generator. The neutron sources moderated by various moderating and absorbing materials was also used. The routine calibration of individual photon dosemeters was carried out using a {sup 137}Cs calibration source in the air kerma quality in the dose range 0.2 mGy to 6 Gy. The type testing of neutron dosemeters was performed in collaboration with Nueherberg laboratory on neutron generator with neutron energies -.57; 1.0;; 5.3 and 15.1 MeV. The fading and angular dependence testing was also included in the tests of both dosemeter systems. (J.K.).

Secondary standard dosimetry laboratory (SSDL)

International Nuclear Information System (INIS)

Md Saion bin Salikin.

1983-01-01

A secondary Standard Dosimetry Laboratory has been established in the Tun Ismail Research Centre, Malaysia as a national laboratory for reference and standardization purposes in the field of radiation dosimetry. This article gives brief accounts on the general information, development of the facility, programmes to be carried out as well as other information on the relevant aspects of the secondary standard dosimetry laboratory. (author)

The Rwanda Field Epidemiology and Laboratory Training Program ...

African Journals Online (AJOL)

The Rwanda Field Epidemiology and Laboratory Training Program (RFELTP) is a 2-year public health leadership development training program that provides applied epidemiology and public health laboratory training while the trainees provide public health service to the Ministry of Health. RFELTP is hosted at the National ...

Radiative heat transfer in the extreme near field.

Science.gov (United States)

Kim, Kyeongtae; Song, Bai; Fernández-Hurtado, Víctor; Lee, Woochul; Jeong, Wonho; Cui, Longji; Thompson, Dakotah; Feist, Johannes; Reid, M T Homer; García-Vidal, Francisco J; Cuevas, Juan Carlos; Meyhofer, Edgar; Reddy, Pramod

2015-12-17

Radiative transfer of energy at the nanometre length scale is of great importance to a variety of technologies including heat-assisted magnetic recording, near-field thermophotovoltaics and lithography. Although experimental advances have enabled elucidation of near-field radiative heat transfer in gaps as small as 20-30 nanometres (refs 4-6), quantitative analysis in the extreme near field (less than 10 nanometres) has been greatly limited by experimental challenges. Moreover, the results of pioneering measurements differed from theoretical predictions by orders of magnitude. Here we use custom-fabricated scanning probes with embedded thermocouples, in conjunction with new microdevices capable of periodic temperature modulation, to measure radiative heat transfer down to gaps as small as two nanometres. For our experiments we deposited suitably chosen metal or dielectric layers on the scanning probes and microdevices, enabling direct study of extreme near-field radiation between silica-silica, silicon nitride-silicon nitride and gold-gold surfaces to reveal marked, gap-size-dependent enhancements of radiative heat transfer. Furthermore, our state-of-the-art calculations of radiative heat transfer, performed within the theoretical framework of fluctuational electrodynamics, are in excellent agreement with our experimental results, providing unambiguous evidence that confirms the validity of this theory for modelling radiative heat transfer in gaps as small as a few nanometres. This work lays the foundations required for the rational design of novel technologies that leverage nanoscale radiative heat transfer.

Pulsed currents carried by whistlers. IV. Electric fields and radiation excited by an electrode

International Nuclear Information System (INIS)

Stenzel, R.L.; Urrutia, J.M.; Rousculp, C.L.

1995-01-01

Electromagnetic properties of current pulses carried by whistler wave packets are obtained from a basic laboratory experiment. While the magnetic field and current density are described in the preceding companion paper (Part III), the present analysis starts with the electric field. The inductive and space charge electric field contributions are separately calculated in Fourier space from the measured magnetic field and Ohm's law along B 0 . Inverse Fourier transformation yields the total electric field in space and time, separated into rotational and divergent contributions. The space-charge density in whistler wave packets is obtained. The cross-field tensor conductivity is determined. The frozen-in condition is nearly satisfied, E+v e xB congruent 0. The dissipation is obtained from Poynting's theorem. The waves are collisionally damped; Landau damping is negligible. A radiation resistance for the electrode is determined. Analogous to Poynting's theorem, the transport of helicity is analyzed. Current helicity is generated by a flow of helicity between pulses traveling in opposite directions which carry opposite signs of helicity. Helicity is dissipated by collisions. These observations complete a detailed description of whistler/current pulses which can occur in various laboratory and space plasmas. copyright 1995 American Institute of Physics

1-2 GeV synchrotron radiation facility at Lawrence Berkeley Laboratory

International Nuclear Information System (INIS)

Berkner, K.H.

1985-10-01

The Advanced Light Source (ALS), a dedicated synchrotron radiation facility optimized to generate soft x-ray and vacuum ultraviole (XUV) light using magnetic insertion devices, was proposed by the Lawrence Berkeley Laboratory in 1982. It consists of a 1.3-GeV injection system, an electron storage ring optimized at 1.3 GeV (with the capability of 1.9-GeV operation), and a number of photon beamlines emanating from twelve 6-meter-long straight sections, as shown in Fig. 1. In addition, 24 bending-magnet ports will be avialable for development. The ALS was conceived as a research tool whose range and power would stimulate fundamentally new research in fields from biology to materials science (1-4). The conceptual design and associated cost estimate for the ALS have been completed and reviewed by the US Department of Energy (DOE), but preliminary design activities have not yet begun. The focus in this paper is on the history of the ALS as an example of how a technical construction project was conceived, designed, proposed, and validated within the framwork of a national laboratory funded largely by the DOE

Radiation and Health Technology Laboratory Capabilities

Energy Technology Data Exchange (ETDEWEB)

Goles, Ronald W.; Johnson, Michelle Lynn; Piper, Roman K.; Peters, Jerry D.; Murphy, Mark K.; Mercado, Mike S.; Bihl, Donald E.; Lynch, Timothy P.

2003-07-15

The Radiological Standards and Calibrations Laboratory, a part of Pacific Northwest National Laboratory (PNNL)(a) performs calibrations and upholds reference standards necessary to maintain traceability to national standards. The facility supports U.S. Department of Energy (DOE) programs at the Hanford Site, programs sponsored by DOE Headquarters and other federal agencies, radiological protection programs at other DOE and commercial nuclear sites and research and characterization programs sponsored through the commercial sector. The laboratory is located in the 318 Building of the Hanford Site's 300 Area. The facility contains five major exposure rooms and several laboratories used for exposure work preparation, low-activity instrument calibrations, instrument performance evaluations, instrument maintenance, instrument design and fabrication work, thermoluminescent and radiochromic Dosimetry, and calibration of measurement and test equipment (M&TE). The major exposure facilities are a low-scatter room used for neutron and photon exposures, a source well room used for high-volume instrument calibration work, an x-ray facility used for energy response studies, a high-exposure facility used for high-rate photon calibration work, a beta standards laboratory used for beta energy response studies and beta reference calibrations and M&TE laboratories. Calibrations are routinely performed for personnel dosimeters, health physics instrumentation, photon and neutron transfer standards alpha, beta, and gamma field sources used throughout the Hanford Site, and a wide variety of M&TE. This report describes the standards and calibrations laboratory.

Guidelines for Member States concerning radiation measurement standards and Secondary Standard Dosimetry Laboratories

International Nuclear Information System (INIS)

1986-01-01

In the early nineteen-sixties an acute need developed for higher dosimetric accuracy in radiation therapy, particularly in developing countries. This need led to the establishment of a number of dosimetry laboratories around the world, specializing in the calibration of radiation therapy dosimeters. In order to co-ordinate the provision of guidance and assistance to such laboratories, the International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) set up a Network of Secondary Standard Dosimetry Laboratories (SSDLs) under their joint aegis, as described in the IAEA booklet 'SSDLs: Development and Trends' (1985). This publication includes detailed criteria for the establishment of these laboratories. The present guidelines deal with the functions and status of SSDLs, in particular with the need for recognition and support by the competent national authorities. (author)

Report on a Workshop on mobile laboratories for monitoring environmental radiation

International Nuclear Information System (INIS)

Andrasi, A,; Nemeth, I.; Zombori, P.; Urban, J.

1992-01-01

The international Workshop organized by the Health Physics Department of the Central Research Institute for Physics and by the Radiation Protection Department of the Paks Nuclear Power Plant was presented in this paper. The aims of the Workshop were the introduction of the mobile laboratories and the demonstration of the applied methods for monitoring environmental radiation in accidental situation. The intercomparison measurements showed that the results given by different participating laboratories (9 institutions from the middle and east European region) agreed well within an acceptable error margin. The demonstration, measurements and discussions were very useful for the participants and this could be a good basis for further developments and cooperations among the participating institutions. (author) 7 figs.; 2 tabs

Health Physics Society program for accreditation of calibration laboratories

International Nuclear Information System (INIS)

West, L.; Masse, F.X.; Swinth, K.L.

1988-01-01

The Health Physics Society has instituted a new program for accreditation of organizations that calibrate radiation survey instruments. The purpose of the program is to provide radiation protection professionals with an expanded means of direct and indirect access to national standards, thus introducing a means for improving the uniformity, accuracy, and quality of ionizing radiation field measurements. Secondary accredited laboratories are expected to provide a regional support basis. Tertiary accredited laboratories are expected to operate on a more local basis and provide readily available expertise to end users. The accreditation process is an effort to provide better measurement assurance for surveys of radiation fields. The status of the accreditation program, general criteria, gamma-ray calibration criteria, and x-ray calibration criteria are reviewed

Adiabatic compression and radiative compression of magnetic fields

International Nuclear Information System (INIS)

Woods, C.H.

1980-01-01

Flux is conserved during mechanical compression of magnetic fields for both nonrelativistic and relativistic compressors. However, the relativistic compressor generates radiation, which can carry up to twice the energy content of the magnetic field compressed adiabatically. The radiation may be either confined or allowed to escape

Difference in Understanding of the Need for Using Radiation in Various Fields between Students Majoring in Radiation and Non-Radiation Related Studies

Energy Technology Data Exchange (ETDEWEB)

Han, Eun Ok [Dept. of Radiological Tecknology, Daegu Health College, Daegu (Korea, Republic of)

2011-12-15

As a way of improving social receptivity of using radiation, this study looked into the difference of understanding the need of using radiation in various fields between students majoring in radiation and non-radiation related studies, who will influence public opinion in the long term. This study also provides data needed for developing efficient strategies for projects promoting the public's awareness of using radiation. Of the students in the 79 schools sampled, 24%(177) were in 4 year colleges and 146 were junior colleges in educational statistics service (http://cesi.kedi.re.kr) In November 2010 1,945 students were selected as a sample, and they were given surveys on the need of using radiation in different fields. As a result, both between students majoring in radiation and non-radiation related studies showed a high level of understanding the need for radiation in the medical field and showed a low level of understanding of the need for radiation in the agricultural field. In all 6 fields of radiation use, students majoring in radiation related studies showed higher levels of understanding for the need to use radiation than students majoring in radiation and non-radiation related studies. In each field, male students and those who have experience medical radiation and relevant education had higher level of understanding. This shows we need to improve the understanding of the cases of female students and those who have not had experiences with medical radiation and to provide relevant education through various kinds of information. The characteristics of the groups that are shown in the results of this study are considered to be helpful for efficiently for project promoting the public's awareness of using radiation.

Difference in Understanding of the Need for Using Radiation in Various Fields between Students Majoring in Radiation and Non-Radiation Related Studies

International Nuclear Information System (INIS)

Han, Eun Ok

2011-01-01

As a way of improving social receptivity of using radiation, this study looked into the difference of understanding the need of using radiation in various fields between students majoring in radiation and non-radiation related studies, who will influence public opinion in the long term. This study also provides data needed for developing efficient strategies for projects promoting the public's awareness of using radiation. Of the students in the 79 schools sampled, 24%(177) were in 4 year colleges and 146 were junior colleges in educational statistics service (http://cesi.kedi.re.kr) In November 2010 1,945 students were selected as a sample, and they were given surveys on the need of using radiation in different fields. As a result, both between students majoring in radiation and non-radiation related studies showed a high level of understanding the need for radiation in the medical field and showed a low level of understanding of the need for radiation in the agricultural field. In all 6 fields of radiation use, students majoring in radiation related studies showed higher levels of understanding for the need to use radiation than students majoring in radiation and non-radiation related studies. In each field, male students and those who have experience medical radiation and relevant education had higher level of understanding. This shows we need to improve the understanding of the cases of female students and those who have not had experiences with medical radiation and to provide relevant education through various kinds of information. The characteristics of the groups that are shown in the results of this study are considered to be helpful for efficiently for project promoting the public's awareness of using radiation.

Building the basis for a comprehensive radiation protection program for a multi-program laboratory

International Nuclear Information System (INIS)

Copenhaver, E.D.

1987-01-01

An explicit, workplace-specific training has been developed, implemented, and documented for all radiation workers. In addition to the radiation worker personnel located at reactors, accelerators, radiochemical laboratories, and waste treatment areas, we have trained other personnel who work in areas where a lesser potential for radiological/chemical exposure exists. These workforces include construction crews, site restoration crews, contracted special services such as scoping and site characterization teams, and short-term visitors. We are developing a comprehensive, integrated approach to radiation protection training suited for a multi-purpose research laboratory. 9 refs., 1 fig., 1 tab

How to prepare a calibration laboratory for ionizing radiation using X rays

International Nuclear Information System (INIS)

Bossio, Francisco; Cardoso, Ricardo de Souza; Quaresma, Daniel da Silva; Batista Filha, Luzianete do Amaral; Peixoto, Jose Guilherme Pereira

2013-01-01

This work shows the main features of a system for calibration and testing of radiation detectors used in low and medium energy. It is based on pre-assembly System Laboratory of Metrology Division (DIMET) Institute of Radiation Protection and Dosimetry (IRD) of the National Commission of Nuclear Energy (CNEN). (author)

Exposures involving perturbations of the EM field have non-linear effects on radiation response and can alter the expression of radiation induced bystander effects

Science.gov (United States)

Mothersill, Carmel; Seymour, Colin

2012-07-01

Our recent data suggest there is a physical component to the bystander signal induced by radiation exposure and that alternative medicine techniques such as Reiki and acupuncture or exposures to weak EM fields alter the response of cells to direct irradiation and either altered bystander signal production or altered the response of cells receiving bystander signals. Our proposed mechanism to explain these findings is that perturbation of electromagnetic (EM) fields is central to the induction of low radiation dose responses especially non-targeted bystander effects. In this presentation we review the alternative medicine data and other data sets from our laboratory which test our hypothesis that perturbation of bio-fields will modulate radiation response in the low dose region. The other data sets include exposure to MRI, shielding using lead and or Faraday cages, the use of physical barriers to bystander signal transmission and the use of membrane channel blockers. The data taken together strongly suggest that EM field perturbation can modulate low dose response and that in fact the EM field rather than the targeted deposition of ionizing energy in the DNA may be the key determinant of dose response in a cell or organism The results also lead us to suspect that at least when chemical transmission is blocked, bystander signals can be transmitted by other means. Our recent experiments suggest light signals and volatiles are not likely. We conclude that alternative medicine and other techniques involving electromagnetic perturbations can modify the response of cells to low doses of ionizing radiation and can induce bystander effects similar to those seen in medium transfer experiments. In addition to the obvious implications for mechanistic studies of low dose effects, this could perhaps provide a novel target to exploit in space radiation protection and in optimizing therapeutic gain during radiotherapy.

Radiation, waves, fields. Causes and effects on environment and health

International Nuclear Information System (INIS)

Leitgeb, N.

1990-01-01

The book discusses static electricity, alternating electric fields, magnetostatic fields, alternating magnetic fields, electromagnetic radiation, optical and ionizing radiation and their hazards and health effects. Each chapter presents basic physical and biological concepts and describes the common radiation sources and their biological effects. Each chapter also contains hints for everyday behaviour as well as in-depth information an specific scientific approaches for assessing biological effects; the latter are addressed to all expert readers working in these fields. There is a special chapter on the problem of so-called 'terrestrial radiation'. (orig.) With 88 figs., 31 tabs [de

Dosimeter calibration facilities and methods at the Radiation Measurement Laboratory of the Centre d'etudes nucleaires, Grenoble

International Nuclear Information System (INIS)

Choudens, H. de; Herbaut, Y.; Haddad, A.; Giroux, J.; Rouillon, J.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

1975-01-01

At the Centre d'etudes nucleaires, Grenoble, the Radiation Measurement Laboratory, which forms part of the Environmental Protection and Research Department, serves the entire Centre for purposes of dosimetry and the calibration of dose meters. The needs of radiation protection are such that one must have facilities for checking periodically the calibration of radiation-monitoring instruments and developing special dosimetry techniques. It was thought a good idea to arrange for the dosimetry and radiation protection team to assist other groups working at the Centre - in particular, the staff of the biology and radiobiology laboratories - and also bodies outside the framework of the French Commissariat a l'energie atomique. Thus, technical collaboration has been established with, for example, Grenoble's Centre hospitalier universitaire (university clinic), which makes use of the facilities and skills available at the Radiation Measurement Laboratory for solving special dosimetry problems. With the Laboratory's facilities it is possible to calibrate dose meters for gamma, beta and neutron measurements

Overview of DOE Oil and Gas Field Laboratory Projects

Science.gov (United States)

Bromhal, G.; Ciferno, J.; Covatch, G.; Folio, E.; Melchert, E.; Ogunsola, O.; Renk, J., III; Vagnetti, R.

2017-12-01

America's abundant unconventional oil and natural gas (UOG) resources are critical components of our nation's energy portfolio. These resources need to be prudently developed to derive maximum benefits. In spite of the long history of hydraulic fracturing, the optimal number of fracturing stages during multi-stage fracture stimulation in horizontal wells is not known. In addition, there is the dire need of a comprehensive understanding of ways to improve the recovery of shale gas with little or no impacts on the environment. Research that seeks to expand our view of effective and environmentally sustainable ways to develop our nation's oil and natural gas resources can be done in the laboratory or at a computer; but, some experiments must be performed in a field setting. The Department of Energy (DOE) Field Lab Observatory projects are designed to address those research questions that must be studied in the field. The Department of Energy (DOE) is developing a suite of "field laboratory" test sites to carry out collaborative research that will help find ways of improving the recovery of energy resources as much as possible, with as little environmental impact as possible, from "unconventional" formations, such as shale and other low permeability rock formations. Currently there are three field laboratories in various stages of development and operation. Work is on-going at two of the sites: The Hydraulic Fracturing Test Site (HFTS) in the Permian Basin and the Marcellus Shale Energy and Environmental Lab (MSEEL) project in the Marcellus Shale Play. Agreement on the third site, the Utica Shale Energy and Environmental Lab (USEEL) project in the Utica Shale Play, was just recently finalized. Other field site opportunities may be forthcoming. This presentation will give an overview of the three field laboratory projects.

The spectra of the standard x-ray qualities used in STUK's Radiation Metrology Laboratory

International Nuclear Information System (INIS)

Tapiovaara, T.; Tapiovaara, M.; Siiskonen, T.; Hakanen, A.

2008-02-01

This report presents the fluence spectra of the standard x-radiation qualities used in the Radiation Dosimetry Laboratory of Radiation and Nuclear Safety Authority (STUK). The spectra were measured in August 2007. The radiation qualities characterised in the report are the ISO Narrow spectrum series (ISO N10-N200, ISO 4037-1:1996) and both of the RQR-spectrum series specified by the IEC (IEC 1267:1994 and IEC 61267:2005). The measurements were made using a high purity Ge-detector and the measured pulse height spectra were corrected to fluence spectra. Spectral characteristics were computed from the spectral data and compared to the requirements in the standards and to the values given in the quality manual of the laboratory. (orig.)

Laboratory Training Manual on the Use of Isotopes and Radiation in Entomology.

Science.gov (United States)

International Atomic Energy Agency, Vienna (Austria).

This publication should be useful for those who are interested in the theory and application of isotopes and radiation in agriculture and entomology. There are two main parts in the publication. Part I, entitled Basic Part, includes topics which an individual should know about radioisotopes and radiation. There are laboratory exercises included in…

Laboratory and Feasibility Study for Industrial Wastewater Effluents Treatment by Radiation

Energy Technology Data Exchange (ETDEWEB)

Zimek, Z.; Głuszewski, W. [Centre for Radiation Research and Technology, Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

2012-07-01

The study of wastewater treatment by radiation regarding chemical processes contribution and physical-chemical separation of highly concentrated non-organic pollutants deposited in specific industrial waste are proposed. Laboratory stand should be build and the study should be performed to confirm possible mechanism of the sedimentation process of nonorganic pollutants during separation initiated by ionizing radiation. Evaluation from technical and economical point of view of this specific radiation technology and feasibility study preparation for industrial facility will be the main output at the final stage of the project. (author)

Laboratory and Feasibility Study for Industrial Wastewater Effluents Treatment by Radiation

International Nuclear Information System (INIS)

Zimek, Z.; Głuszewski, W.

2012-01-01

The study of wastewater treatment by radiation regarding chemical processes contribution and physical-chemical separation of highly concentrated non-organic pollutants deposited in specific industrial waste are proposed. Laboratory stand should be build and the study should be performed to confirm possible mechanism of the sedimentation process of nonorganic pollutants during separation initiated by ionizing radiation. Evaluation from technical and economical point of view of this specific radiation technology and feasibility study preparation for industrial facility will be the main output at the final stage of the project. (author)

Radiation breeding researches in gamma field. Results of researches

International Nuclear Information System (INIS)

Morishita, Toshikazu

2006-01-01

Abstract of radiation breeding researches and outline of gamma field in IRB (Institute of Radiation Breeding) are described. The gamma field is a circular field of 100 m radius with 88.8TBqCo-60 source at the center. The field is surrounded by a shielding dike of 8 m in height. The effects of gamma irradiation on the growing plants, mutant by gamma radiation and plant molecular biological researches using mutant varieties obtained by the gamma field are explained. For examples, Japanese pear, chrysanthemum, Cytisus, Eustoma grandiflorum, Manila grass, tea and rose are reported. The mutant varieties in the gamma field, nine mutant varieties of flower colors in chrysanthemum, evergreen mutant lines in Manila grass, selection of self-compatible mutants in tea plant, and the plants of the gamma field recently are shown. (S.Y.)

78 FR 47007 - National Environmental Policy Act; Santa Susana Field Laboratory

Science.gov (United States)

2013-08-02

... project Web site address listed below. http://www.nasa.gov/agency/nepa/news/SSFL.html . ADDRESSES...; Santa Susana Field Laboratory AGENCY: National Aeronautics and Space Administration (NASA). ACTION... Environmental Cleanup Activities for the NASA-administered portion of the Santa Susana Field Laboratory (SSFL...

Radiation phase of a dipole field

International Nuclear Information System (INIS)

Shunovsky, A.S.

1998-01-01

In the case of a dipole electromagnetic radiation, the operator of the 'radiation phase' is defined. It is shown that this operator has a discrete spectrum with eigenvalues, lying in the segment [0,2π]. Some properties of the radiation phase and polarization are discussed. Seventy years of investigation of the problem of quantum phase led to the conclusion that there is no unique quantum variable, determining universally the measured phase properties of electromagnetic radiation. The operator constructions, describing cosine and sine of the phase, could be different schemes of measurement. This fact has accurately been confirmed by a number of recent experiments. Thus, it seems to be quite plausible that the quantum phase properties of an electromagnetic radiation are determined by interaction photons with a macroscopic detecting device. It is pertinent to ask the following question. Are the quantum phase properties of radiation completely determined by such an interaction or the photons have their own inherent phase properties which might be measured even if they are modified by interaction with a detecting device? The universally recognized fact is that the vacuum state of field is degenerated with respect to phase. If a quantum radiation has its inherent phase properties, it means that the degeneration is taken off in the process of generation which is an interaction of the vacuum field with excited states of atoms or molecules. By virtue of this picture proposed in, what all one can expect is that the inherent quantum phase properties of radiation are completely determined by a source via the conservation laws, describing the generation process. Even in this way, it seems to determine a unique quantum phase of radiation. As a matter of fact, there are two conservation laws, admitting a nontrivial angular dependence

Study of detectors in beta radiation fields

International Nuclear Information System (INIS)

Albuquerque, M. da P.P.; Xavier, M.; Caldas, L.V.E.

1987-01-01

Several commercial detectors used with gamma or X radiation are studied. Their sensibility and energetic dependence are analysed in exposures of beta radiation fields. A comparative evaluation with the reference detector (the extrapolation chamber) is presented. (M.A.C.) [pt

Water Quality & Pollutant Source Monitoring: Field and Laboratory Procedures. Training Manual.

Science.gov (United States)

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

This training manual presents material on techniques and instrumentation used to develop data in field monitoring programs and related laboratory operations concerned with water quality and pollution monitoring. Topics include: collection and handling of samples; bacteriological, biological, and chemical field and laboratory methods; field…

Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale

Energy Technology Data Exchange (ETDEWEB)

Kawamura, Yoshiyuki [Department of Intelligent Mechanical Engineering, Fukuoka Institute of Technology, 3-30-1 Wajirohigashi, Higashiku, Fukuoka 811-0295 (Japan)

2016-01-15

The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO{sub 2}) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO{sub 2} gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value.

Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale.

Science.gov (United States)

Kawamura, Yoshiyuki

2016-01-01

The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO2) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO2 gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value.

Urban and marine corrosion: Comparative behaviour between field and laboratory conditions

Energy Technology Data Exchange (ETDEWEB)

Iribarren Laco, J.I.; Liesa Mestres, F.; Bilurbina Alter, L. [Departament d' Enginyeria Quimica E.T.S.E.I.B. Universitat Politecnica de Catalunya, Barcelona (Spain); Cadena Villota, F. [Departamento de Materiales, Escuela Politecnica Nacional, Quito (Ecuador)

2004-09-01

A detailed study of the corrosion phenomena of carbon steel has been investigated in this work by means of the comparison of field and laboratory tests. Two areas of the metropolitan area of Barcelona (Spain) were selected to carry out the field tests, whereas two different solutions of sodium chloride and sodium hydrogen sulfite were used to simulate the field conditions by means of cyclic laboratory tests. The corrosion rate has been evaluated from the weight loss of the specimens and the morphology surface has been visualized by optical and scanning electron microscopy. Corrosion products and contaminants have been analyzed by X-ray diffraction and energy-dispersive X-ray spectroscopy, respectively. The penetration results can be adjusted to the Passano equation and the corrosivity degree can be assigned in accordance with ISO standards. A correlation between field and laboratory tests has been found, by comparing the specimens with the same degree of corrosion, showing the validity of the accelerated laboratory tests in order to simulate the field conditions. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Laboratory and Field Investigations of Small Crater Repair Technologies

National Research Council Canada - National Science Library

Priddy, Lucy P; Tingle, Jeb S; McCaffrey, Timothy J; Rollings, Ray S

2007-01-01

.... This airfield damage repair (ADR) investigation consisted of laboratory testing of selected crater fill and capping materials, as well as full-scale field testing of small crater repairs to evaluate field mixing methods, installation...

Personnel radiation dosimetry laboratory accreditation programme for thermoluminescent dosimeters : a proposal

International Nuclear Information System (INIS)

Bhatt, B.C.; Srivastava, J.K.; Iyer, P.S.; Venkatraman, G.

1993-01-01

Accreditation for thermoluminescent dosimeters is the process of evaluating a programme intending to use TL personnel dosimeters to measure, report and record dose equivalents received by radiation workers. In order to test the technical competence for conducting personnel dosimetry service as well as to decentralize personnel monitoring service, it has been proposed by Radiological Physics Division (RPhD) to accredit some of the laboratories, in the country. The objectives of this accreditation programme are: (i) to give recognition to competent dosimetry processors, and (ii) to provide periodic evaluation of dosimetry processors, including review of internal quality assurance programme to improve the quality of personnel dosimetry processing. The scientific support for the accreditation programme will be provided by the scientific staff from Radiological Physics Division (RPhD) and Radiation Protection Services Division (RPSD). This paper describes operational and technical requirements for the Personnel Radiation Dosimetry Laboratory Accreditation Programme for Thermoluminescent Dosimeters for Personnel Dosimetry Processors. Besides, many technical documents dealing with the TL Personnel Dosimeter System have been prepared. (author). 5 refs., 2 figs

DOE Task Force meeting on Electrical Breakdown of Insulating Ceramics in a High Radiation Field

International Nuclear Information System (INIS)

Green, P.H.

1991-08-01

This volume contains the abstracts and presentation material from the Research Assistance Task Force Meeting ''Electrical Breakdown of Insulating Ceramics in a High-Radiation Field.'' The meeting was jointly sponsored by the Office of Basic Energy Sciences and the Office of Fusion Energy of the US Department of Energy in Vail, Colorado, May 28--June 1, 1991. The 26 participants represented expertise in fusion, radiation damage, electrical breakdown, ceramics, and semiconductor and electronic structures. These participants came from universities, industries, national laboratories, and government. The attendees represented eight nations. The Task Force meeting was organized in response to the recent discovery that a combination of temperature, electric field, and radiation for an extended period of time has an unexplained adverse effect in ceramics, termed radiation-enhanced electrical degradation (REED). REED occurs after an incubation period and continues to accelerate with irradiation until the ceramics can no longer be regarded as insulators. It appears that REED is irreversible and the ceramic insulators cannot be readily annealed or otherwise repaired for future services. This effect poses a serious threat for fusion reactors, which require electrical insulators in diagnostic devices, in radio frequency and neutral beam systems, and in magnetic assemblies. The problem of selecting suitable electrical insulating materials in thus far more serious than previously anticipated

Radiation chemistry at the Metallurgical Laboratory, Manhattan Project, University of Chicago (1942-1947) and the Argonne National Laboratory, Argonne, IL (1947-1984)

International Nuclear Information System (INIS)

Gordon, S.

1989-01-01

The events in radiation chemistry which occurred in the Manhattan Project Laboratory and Argonne National Laboratory during World War II are reviewed. Research programmes from then until the present day are presented, with emphasis on pulse radiolysis studies. (UK)

Individual Dosimetry for High Energy Radiation Fields

International Nuclear Information System (INIS)

Spurny, F.

1999-01-01

The exposure of individuals on board aircraft increased interest in individual dosimetry in high energy radiation fields. These fields, both in the case of cosmic rays as primary radiation and at high energy particle accelerators are complex, with a large diversity of particle types, their energies, and linear energy transfer (LET). Several already existing individual dosemeters have been tested in such fields. For the component with high LET (mostly neutrons) etched track detectors were tested with and without fissile radiators, nuclear emulsions, bubble detectors for both types available and an albedo dosemeter. Individual dosimetry for the low LET component has been performed with thermoluminescent detectors (TLDs), photographic film dosemeters and two types of electronic individual dosemeters. It was found that individual dosimetry for the low LET component was satisfactory with the dosemeters tested. As far as the high LET component is concerned, there are problems with both the sensitivity and the energy response. (author)

Asymmetric active nano-particles for directive near-field radiation

DEFF Research Database (Denmark)

Arslanagic, Samel; Thorsen, Rasmus O.

2016-01-01

In this work, we demonstrate the potential of cylindrical active coated nano-particles with certain geometrical asymmetries for the creation of directive near-field radiation. The particles are excited by a near-by magnetic line source, and their performance characteristics are reported in terms...... of radiated power, near-field and power flow distributions as well as the far-field directivity....

Hawking radiation of a vector field and gravitational anomalies

International Nuclear Information System (INIS)

Murata, Keiju; Miyamoto, Umpei

2007-01-01

Recently, the relation between Hawking radiation and gravitational anomalies has been used to estimate the flux of Hawking radiation for a large class of black objects. In this paper, we extend the formalism, originally proposed by Robinson and Wilczek, to the Hawking radiation of vector particles (photons). It is explicitly shown, with the Hamiltonian formalism, that the theory of an electromagnetic field on d-dimensional spherical black holes reduces to one of an infinite number of massive complex scalar fields on 2-dimensional spacetime, for which the usual anomaly-cancellation method is available. It is found that the total energy emitted from the horizon for the electromagnetic field is just (d-2) times that for a scalar field. The results support the picture that Hawking radiation can be regarded as an anomaly eliminator on horizons. Possible extensions and applications of the analysis are discussed

Tour of the Standards and Calibrations Laboratory

International Nuclear Information System (INIS)

Elliott, J.H.

1978-01-01

This tour of Lawrence Livermore Laboratory's Standards and Calibrations Laboratory is intended as a guide to the capabilities of and services offered by this unique laboratory. Described are the Laboratory's ability to provide radiation fields and measurements for dosimeters, survey instruments, spectrometers, and sources and its available equipment and facilities. The tour also includes a survey of some Health Physics and interdepartmental programs supported by the Standards and Calibrations Laboratory and a listing of applicable publications

Comparison of leach results from field and laboratory prepared samples

International Nuclear Information System (INIS)

Oblath, S.B.; Langton, C.A.

1985-01-01

The leach behavior of saltstone prepared in the laboratory agrees well with that from samples mixed in the field using the Littleford mixer. Leach rates of nitrates and cesium from the current reference formulation saltstone were compared. The laboratory samples were prepared using simulated salt solution; those in the field used Tank 50 decontaminated supernate. For both nitrate and cesium, the field and laboratory samples showed nearly identical leach rates for the first 30 to 50 days. For the remaining period of the test, the field samples showed higher leach rates with the maximum difference being less than a factor of three. Ruthenium and antimony were present in the Tank 50 supernate in known amounts. Antimony-125 was observed in the leachate and a fractional leach rate was calculated to be at least a factor of ten less than that of 137 Cs. No 106 Ru was observed in the leachate, and the release rate was not calculated. However, based on the detection limits for the analysis, the ruthenium leach rate must also be at least a factor of ten less than cesium. These data are the first measurements of the leach rates of Ru and Sb from saltstone. The nitrate leach rates for these samples were 5 x 10 -5 grams of nitrate per square cm per day after 100 days for the laboratory samples and after 200 days for the field samples. These values are consistent with the previously measured leach rates for reference formulation saltstone. The relative standard deviation in the leach rate is about 15% for the field samples, which all were produced from one batch of saltstone, and about 35% for the laboratory samples, which came from different batches. These are the first recorded estimates of the error in leach rates for saltstone

Radiation anomaly detection algorithms for field-acquired gamma energy spectra

Science.gov (United States)

Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ron; Guss, Paul; Mitchell, Stephen

2015-08-01

The Remote Sensing Laboratory (RSL) is developing a tactical, networked radiation detection system that will be agile, reconfigurable, and capable of rapid threat assessment with high degree of fidelity and certainty. Our design is driven by the needs of users such as law enforcement personnel who must make decisions by evaluating threat signatures in urban settings. The most efficient tool available to identify the nature of the threat object is real-time gamma spectroscopic analysis, as it is fast and has a very low probability of producing false positive alarm conditions. Urban radiological searches are inherently challenged by the rapid and large spatial variation of background gamma radiation, the presence of benign radioactive materials in terms of the normally occurring radioactive materials (NORM), and shielded and/or masked threat sources. Multiple spectral anomaly detection algorithms have been developed by national laboratories and commercial vendors. For example, the Gamma Detector Response and Analysis Software (GADRAS) a one-dimensional deterministic radiation transport software capable of calculating gamma ray spectra using physics-based detector response functions was developed at Sandia National Laboratories. The nuisance-rejection spectral comparison ratio anomaly detection algorithm (or NSCRAD), developed at Pacific Northwest National Laboratory, uses spectral comparison ratios to detect deviation from benign medical and NORM radiation source and can work in spite of strong presence of NORM and or medical sources. RSL has developed its own wavelet-based gamma energy spectral anomaly detection algorithm called WAVRAD. Test results and relative merits of these different algorithms will be discussed and demonstrated.

Topological magnetoelectric effects in microwave far-field radiation

Energy Technology Data Exchange (ETDEWEB)

Berezin, M.; Kamenetskii, E. O.; Shavit, R. [Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel)

2016-07-21

Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.

Differential Detector for Measuring Radiation Fields

International Nuclear Information System (INIS)

Broide, A.; Marcus, E.; Brandys, I.; Schwartz, A.; Wengrowicz, U.; Levinson, S.; Seif, R.; Sattinger, D.; Kadmon, Y.; Tal, N.

2004-01-01

In case of a nuclear accident, it is essential to determine the source of radioactive contamination in order to analyze the risk to the environment and to the population. The radiation source may be a radioactive plume on the air or an area on the ground contaminated with radionuclides. Most commercial radiation detectors measure only the radiation field intensity but are unable to differentiate between the radiation sources. Consequently, this limitation causes a real problem in analyzing the potential risk to the near-by environment, since there is no data concerning the contamination ratios in the air and on the ground and this prevents us from taking the required steps to deal with the radiation event. This work presents a GM-tube-based Differential Detector, which enables to determine the source of contamination

Near-field radiative heat transfer between clusters of dielectric nanoparticles

International Nuclear Information System (INIS)

Dong, J.; Zhao, J.M.; Liu, L.H.

2017-01-01

In this work, we explore the near-field radiative heat transfer between two clusters of silicon carbide (SiC) nanoparticles using the many-body radiative heat transfer theory. The effects of fractal dimension of clusters, many-body interaction between nanoparticles and relative orientation of clusters on the thermal conductance are studied. Meanwhile, the applicability of the equivalent volume spheres (EVS) approximation for near-field radiative heat transfer between clusters is examined. It is observed that the thermal conductance is larger for clusters with larger fractal dimension, which is more significant in the near-field. The thermal conductance of EVS resembles that of the clusters, but EVS overestimates the conductance of clusters, especially in the near-field. Compared to the case of two nanoparticles, the conductance of nanoparticle clusters decays much slower with increasing distance in the near-field, but shares similar dependence on the distance in the far-field. The thermal conductance of SiC nanoparticle clusters is inhibited by the many-body interaction when surface phonon polariton is supported but enhanced at frequencies close to the resonance frequency. The total thermal conductance is decreased due to many-body interaction among particles in the cluster. The relative orientation between the clusters is also an important factor in the near-field, especially for clusters with lower fractal dimension. - Highlights: • Near-field radiative heat transfer between clusters of nanoparticles is studied. • The many-body radiative heat transfer theory is applied for rigorous analysis. • The accuracy of equivalent volume spheres approximation is examined. • Clusters with larger fractal dimension have larger radiative thermal conductance. • Many-body interaction inhibits the total radiative thermal conductance.

Electromagnetic field, excited by monodirected X-radiation pulse

International Nuclear Information System (INIS)

Zhemerov, A.V.; Metelkin, E.V.

1994-01-01

Parameters of electromagnetic field, generated in the atmosphere by monodirected pulse source of X radiation located at the altitude of approximately several kilometers have been estimated by the method of delayed potentials. The source radiation is directed towards the Earth surface. The conclusion was made that restricted areas of approximately 1 km with considerable pulse electromagnetic fields can be created on the Earth surface

A mobile radiological laboratory for rapid response to off-site radiation emergencies

Energy Technology Data Exchange (ETDEWEB)

Katoch, D. S.; Sharma, R. C.; Mehta, D. J.; Raj, V. Venkat [Bhabha Atomic Research Centre, Mumbai (India)

2002-07-01

A mobile radiological laboratory (MRL) has been designed and developed primarily for providing a rapid response to radiation emergencies arising as a consequence of nuclear and/or radiological accidents. It is equipped specifically to monitor the environment and provide quick assessment of radiological hazards to the population living within a radius of 30 km around a nuclear facility. In this paper, various design features of an Indian MRL together with the details of installed equipment are presented. The MRL has been designed for a continuous outdoor operation of about two weeks. It is built on a 10.70 m long air suspension Bus Chassis and has four sections : Driver's Cabin, Main Counting Laboratory, Whole Body Monitor and Rear section housing general utilities. The electric power is provided by two diesel generators during field operation and by 230 V AC mains supply at headquarters and wherever possible. The equipment installed in the MRL includes : Alpha, beta and gamma counting systems and low and high volume air samplers for the assessment of radioactive contents in the samples of air, water, soil and vegetation; environment dose rate meters and a variety of survey meters for evaluating any potential increase in radiation levels; personal dosimeters to control external radiation exposure; personal protective equipment for avoiding skin and clothing contamination; a chair type of whole body monitor for the assessment of internal radioactive contamination of the human body, in particular, thyroidal uptake of radioiodine; an automatic weather station for recording continuously the meteorological parameters and a satellite based global positioning system to continuously track and display the geographical location of the MRL. The calibrations of the installed equipment are presently in progress. Preliminary results obtained for the methods needed for rapid detection of gamma emitters in the environment and human body, namely, in situ gamma spectrometry and

A locally designed mobile laboratory for radiation analysis and monitoring in qatar. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

Abou-Leila, H; El-Samman, H; Mahmoud, H [Physics Department, University of qatar, Doha (Qatar)

1996-03-01

A description of a mobile laboratory for radiation analysis and monitoring, completely designed in qatar and equipped at qatar university, is given. It consists of a van equipped with three scintillation detectors mounted on the front bumper. The detectors can monitor gamma radiations along the path of the laboratory over an angle range 120 degree. One Eberline radiation monitoring station is mounted on the roof. The laboratory is also equipped with several, and neutron survey meters in addition to some sampling equipment. All equipment used are powered with solar panels. The characteristics and performance of solar power/stabilized A C conversion is given. Data acquisition from the three scintillation detectors is performed by adding the outputs of the three detectors and storing the total as a function of time in a computer based multi-channel analyzer (MCA) operated in the MSC mode. The acquisition can be switched easily to the PHA mode to analyze gamma spectra from any possible contamination source. The laboratory was used in several environmental and possible contamination missions. Some results obtained during some of these missions are given. 4 figs.

A locally designed mobile laboratory for radiation analysis and monitoring in qatar. Vol. 4

International Nuclear Information System (INIS)

Abou-Leila, H.; El-Samman, H.; Mahmoud, H.

1996-01-01

A description of a mobile laboratory for radiation analysis and monitoring, completely designed in qatar and equipped at qatar university, is given. It consists of a van equipped with three scintillation detectors mounted on the front bumper. The detectors can monitor gamma radiations along the path of the laboratory over an angle range 120 degree. One Eberline radiation monitoring station is mounted on the roof. The laboratory is also equipped with several, and neutron survey meters in addition to some sampling equipment. All equipment used are powered with solar panels. The characteristics and performance of solar power/stabilized A C conversion is given. Data acquisition from the three scintillation detectors is performed by adding the outputs of the three detectors and storing the total as a function of time in a computer based multi-channel analyzer (MCA) operated in the MSC mode. The acquisition can be switched easily to the PHA mode to analyze gamma spectra from any possible contamination source. The laboratory was used in several environmental and possible contamination missions. Some results obtained during some of these missions are given. 4 figs

Potential scattering in the presence of a static magnetic field and a radiation field of arbitrary polarization

Science.gov (United States)

Ferrante, G.; Zarcone, M.; Nuzzo, S.; McDowell, M. R. C.

1982-05-01

Expressions are obtained for the total cross sections for scattering of a charged particle by a potential in the presence of a static uniform magnetic field and a radiation field of arbitrary polarization. For a Coulomb field this is closely related to the time reverse of photoionization of a neutral atom in a magnetic field, including multiphoton effects off-resonance. The model is not applicable when the radiation energy approaches one of the quasi-Landau state separations. The effects of radiation field polarization are examined in detail.

Monte Carlo simulation of muon radiation environment in China Jinping Underground Laboratory

International Nuclear Information System (INIS)

Su Jian; Zeng Zhi; Liu Yue; Yue Qian; Ma Hao; Cheng Jianping

2012-01-01

Muon radiation background of China Jinping Underground Laboratory (CJPL) was simulated by Monte Carlo method. According to the Gaisser formula and the MUSIC soft, the model of cosmic ray muons was established. Then the yield and the average energy of muon-induced photons and muon-induced neutrons were simulated by FLUKA. With the single-energy approximation, the contribution to the radiation background of shielding structure by secondary photons and neutrons was evaluated. The estimation results show that the average energy of residual muons is 369 GeV and the flux is 3.17 × 10 -6 m -2 · s -1 . The fluence rate of secondary photons is about 1.57 × 10 -4 m -2 · s -1 , and the fluence rate of secondary neutrons is about 8.37 × 10 -7 m -2 · s -1 . The muon radiation background of CJPL is lower than those of most other underground laboratories in the world. (authors)

Stanford Synchrotron Radiation Laboratory activity report for 1987

Energy Technology Data Exchange (ETDEWEB)

Robinson, S.; Cantwell, K. [eds.

1988-12-31

During 1987, SSRL achieved many significant advances and reached several major milestones utilizing both SPEAR and PEP as synchrotron radiation sources as described in this report. Perhaps the following two are worthy of particular mention: (1) SPEAR reached an all time high of 4,190 delivered user-shifts during calendar year 1987, highlights of the many scientific results are given; (2) during a 12 day run in December of 1987, PEP was operated in a low emittance mode (calculated emittance 6.4 nanometer-radians) at 7.1 GeV with currents up to 33 mA. A second undulator beam line on PEP was commissioned during this run and used to record many spectra showing the extremely high brightness of the radiation. PEP is now by far the highest brightness synchrotron radiation source in the world. The report is divided into the following sections: (1) laboratory operations; (2) accelerator physics programs; (3) experimental facilities; (4) engineering division; (5) conferences and workshops; (6) SSRL organization; (7) experimental progress reports; (8) active proposals; (9) SSRL experiments and proposals by institution; and (10) SSRL publications.

HPS instrument calibration laboratory accreditation program

Energy Technology Data Exchange (ETDEWEB)

Masse, F.X; Eisenhower, E.H.; Swinth, K.L.

1993-12-31

The purpose of this paper is to provide an accurate overview of the development and structure of the program established by the Health Physics Society (HPS) for accrediting instrument calibration laboratories relative to their ability to accurately calibrate portable health physics instrumentation. The purpose of the program is to provide radiation protection professionals more meaningful direct and indirect access to the National Institute of Standards and Technology (NIST) national standards, thus introducing a means for improving the uniformity, accuracy, and quality of ionizing radiation field measurements. The process is designed to recognize and document the continuing capability of each accredited laboratory to accurately perform instrument calibration. There is no intent to monitor the laboratory to the extent that each calibration can be guaranteed by the program; this responsibility rests solely with the accredited laboratory.

Suppression of sound radiation to far field of near-field acoustic communication system using evanescent sound field

Science.gov (United States)

Fujii, Ayaka; Wakatsuki, Naoto; Mizutani, Koichi

2016-01-01

A method of suppressing sound radiation to the far field of a near-field acoustic communication system using an evanescent sound field is proposed. The amplitude of the evanescent sound field generated from an infinite vibrating plate attenuates exponentially with increasing a distance from the surface of the vibrating plate. However, a discontinuity of the sound field exists at the edge of the finite vibrating plate in practice, which broadens the wavenumber spectrum. A sound wave radiates over the evanescent sound field because of broadening of the wavenumber spectrum. Therefore, we calculated the optimum distribution of the particle velocity on the vibrating plate to reduce the broadening of the wavenumber spectrum. We focused on a window function that is utilized in the field of signal analysis for reducing the broadening of the frequency spectrum. The optimization calculation is necessary for the design of window function suitable for suppressing sound radiation and securing a spatial area for data communication. In addition, a wide frequency bandwidth is required to increase the data transmission speed. Therefore, we investigated a suitable method for calculating the sound pressure level at the far field to confirm the variation of the distribution of sound pressure level determined on the basis of the window shape and frequency. The distribution of the sound pressure level at a finite distance was in good agreement with that obtained at an infinite far field under the condition generating the evanescent sound field. Consequently, the window function was optimized by the method used to calculate the distribution of the sound pressure level at an infinite far field using the wavenumber spectrum on the vibrating plate. According to the result of comparing the distributions of the sound pressure level in the cases with and without the window function, it was confirmed that the area whose sound pressure level was reduced from the maximum level to -50 dB was

Characterization of beta radiation fields using radiochromic films

International Nuclear Information System (INIS)

Benavente, Jhonny A.; Silva, Teogenes A. da

2011-01-01

The objective of this work was to study the response of radiochromic films for beta radiation fields in terms of absorbed dose. The reliability of the EBT model Gafchromic radiochromic film was studied. A 9800 XL model Microtek, transmission scanner, a 369 model X-Rite optical densitometer and a Mini 1240 Shimadzu UV spectrophotometer were used for measurement comparisons. Calibration of the three systems was done with irradiated samples of radiochromic films with 0.1; 0.3; 0.5; 0.8; 1.0; 1.5; 2.0; 2.5; 3.0; 3.5; 4.5 e 5.0 Gy in beta radiation field from a Sr-90/Y-90 source. Calibration was performed by establishing a correlation between the absorbed dose values and the corresponding radiochromic responses. Results showed significant differences in the absorbed dose values obtained with the three methods. Absorbed dose values showed errors from 0.6 to 4.4%, 0.3 to 31.8% and 0.2 to 47.3% for the Microtek scanner, the X-Rite Densitometer and the Shimadzu spectrophotometer, respectively. Due to the easy acquisition and use for absorbed dose measurements, the densitometer and the spectrophotometer showed to be suitable techniques to evaluate radiation dose in relatively homogeneous fields. In the case of inhomogeneous fields or for a two dimension mapping of radiation fields to identify anisotropies, the scanner technique is the most recommended. (author)

Field electron emission spectrometer combined with field ion/electron microscope as a field emission laboratory

International Nuclear Information System (INIS)

Shkuratov, S.I.; Ivanov, S.N.; Shilimanov, S.N.

1996-01-01

The facility, combining the field ion microscope, field electron emission microscope and field electron emission spectrometer, is described. Combination of three methodologies makes it possible to carry out the complete cycle of emission studies. Atom-plane and clean surface of the studied samples is prepared by means of field evaporation of the material atom layers without any thermal and radiation impact. This enables the study of atom and electron structure of clean surface of the wide range materials, the study whereof through the field emission methods was previously rather difficult. The temperature of the samples under study changes from 75 up to 2500 K. The energy resolution of the electron analyzer equals 30 MeV. 19 refs., 10 figs

Radiation effects on materials in the near-field of nuclear waste repository. 1998 annual progress report

International Nuclear Information System (INIS)

Ewing, R.C.; Wang, L.M.

1998-01-01

'Site restoration activities at DOE facilities and the permanent disposal of nuclear waste generated at DOE facilities involve working with and within various types and levels of radiation fields. Once the nuclear waste is incorporated into a final form, radioactive decay will decrease the radiation field over geologic time scales, but the alpha-decay dose for these solids will still reach values as high as 10 18 alpha-decay events/gm in periods as short as 1,000 years. This dose is well within the range for which important chemical (e.g., increased leach rate) and physical (e.g., volume expansion) changes may occur in crystalline ceramics. Release and sorption of long-lived actinides (e.g., 237 Np) can provide a radiation exposure to backfill materials, and changes in important properties (e.g., cation exchange capacity) may occur. The objective of this research program is to evaluate the long term radiation effects in the materials in the near-field of a nuclear waste repository with accelerated experiments in the laboratory using energetic particles (electrons, ions and neutrons). Experiments on the microstructural evolution during irradiation of two important groups of materials, sheet silicates (e.g., clays) and zeolites (analcime), have been conducted; and studies of radiation-induced changes in chemical properties (e.g. cation exchange capacity) are underway. As of the mid-2nd year of the 3-year project, experiments on the microstructural evolution during irradiation of two important group of materials, sheet silicates (mica) and zeolites (analcime), have been conducted; and studies of radiation-induced changes in chemical properties (e.g., cation exchange capacity) are underway.'

Exposure to electromagnetic fields from smart utility meters in GB; part I) laboratory measurements.

Science.gov (United States)

Peyman, Azadeh; Addison, Darren; Mee, Terry; Goiceanu, Cristian; Maslanyj, Myron; Mann, Simon

2017-05-01

Laboratory measurements of electric fields have been carried out around examples of smart meter devices used in Great Britain. The aim was to quantify exposure of people to radiofrequency signals emitted from smart meter devices operating at 2.4 GHz, and then to compare this with international (ICNIRP) health-related guidelines and with exposures from other telecommunication sources such as mobile phones and Wi-Fi devices. The angular distribution of the electric fields from a sample of 39 smart meter devices was measured in a controlled laboratory environment. The angular direction where the power density was greatest was identified and the equivalent isotropically radiated power was determined in the same direction. Finally, measurements were carried out as a function of distance at the angles where maximum field strengths were recorded around each device. The maximum equivalent power density measured during transmission around smart meter devices at 0.5 m and beyond was 15 mWm -2 , with an estimation of maximum duty factor of only 1%. One outlier device had a maximum power density of 91 mWm -2 . All power density measurements reported in this study were well below the 10 W m -2 ICNIRP reference level for the general public. Bioelectromagnetics. 2017;38:280-294. © 2017 Crown copyright. BIOELECTROMAGNETICS © 2017 Wiley Periodicals, Inc. © 2017 Crown copyright. BIOELECTROMAGNETICS © 2017 Wiley Periodicals, Inc.

Near-field radiative heat transfer in mesoporous alumina

International Nuclear Information System (INIS)

Li Jing; Feng Yan-Hui; Zhang Xin-Xin; Huang Cong-Liang; Wang Ge

2015-01-01

The thermal conductivity of mesoporous material has aroused the great interest of scholars due to its wide applications such as insulation, catalyst, etc. Mesoporous alumina substrate consists of uniformly distributed, unconnected cylindrical pores. Near-field radiative heat transfer cannot be ignored, when the diameters of the pores are less than the characteristic wavelength of thermal radiation. In this paper, near-field radiation across a cylindrical pore is simulated by employing the fluctuation dissipation theorem and Green function. Such factors as the diameter of the pore, and the temperature of the material are further analyzed. The research results show that the radiative heat transfer on a mesoscale is 2∼4 orders higher than on a macroscale. The heat flux and equivalent thermal conductivity of radiation across a cylindrical pore decrease exponentially with pore diameter increasing, while increase with temperature increasing. The calculated equivalent thermal conductivity of radiation is further developed to modify the thermal conductivity of the mesoporous alumina. The combined thermal conductivity of the mesoporous alumina is obtained by using porosity weighted dilute medium and compared with the measurement. The combined thermal conductivity of mesoporous silica decreases gradually with pore diameter increasing, while increases smoothly with temperature increasing, which is in good agreement with the experimental data. The larger the porosity, the more significant the near-field effect is, which cannot be ignored. (paper)

Computational methods in several fields of radiation dosimetry

International Nuclear Information System (INIS)

Paretzke, Herwig G.

2010-01-01

Full text: Radiation dosimetry has to cope with a wide spectrum of applications and requirements in time and size. The ubiquitous presence of various radiation fields or radionuclides in the human home, working, urban or agricultural environment can lead to various dosimetric tasks starting from radioecology, retrospective and predictive dosimetry, personal dosimetry, up to measurements of radionuclide concentrations in environmental and food product and, finally in persons and their excreta. In all these fields measurements and computational models for the interpretation or understanding of observations are employed explicitly or implicitly. In this lecture some examples of own computational models will be given from the various dosimetric fields, including a) Radioecology (e.g. with the code systems based on ECOSYS, which was developed far before the Chernobyl reactor accident, and tested thoroughly afterwards), b) Internal dosimetry (improved metabolism models based on our own data), c) External dosimetry (with the new ICRU-ICRP-Voxelphantom developed by our lab), d) Radiation therapy (with GEANT IV as applied to mixed reactor radiation incident on individualized voxel phantoms), e) Some aspects of nanodosimetric track structure computations (not dealt with in the other presentation of this author). Finally, some general remarks will be made on the high explicit or implicit importance of computational models in radiation protection and other research field dealing with large systems, as well as on good scientific practices which should generally be followed when developing and applying such computational models

Effects of ionizing radiation and steady magnetic field on erythrocytes

International Nuclear Information System (INIS)

Ivanov, S. P.; Galutzov, B. P.; Kuzmanova, M. A.; Markov, M. S.

1996-01-01

A complex biophysical test for studying the effects of ionizing and non-ionizing radiation has been developed. The following cell and membrane parameters have been investigated: cell size, cell shape, cell distribution by size, electrophoretic mobility, extent of hemolysis, membrane transport and membrane impedance. Gamma ray doses of 2.2 Gy and 3.3 Gy were used as ionizing radiation and steady (DC) magnetic field of 5-90 mT representing the non-ionizing radiation. Erythrocytes from humans and rats were exposed in vitro to both ionizing and non-ionizing radiation. In some experiments ionizing radiation was applied in vivo as well. Each of the simultaneously studied parameters have been found to change as a function of applied radiation. The proposed test allows an estimation of the changes in the elastic, rheological and electrical parameters of cells and biological membranes. Results indicate that ionizing radiation is significantly more effective in an in vivo application, while magnetic fields are more effective when applied in vitro. Surprisingly, steady magnetic fields were found to act as protector against some harmful effects of ionizing radiation. (authors)

The LBL [Lawrence Berkeley Laboratory] 1-2 GeV synchrotron radiation source

International Nuclear Information System (INIS)

Cornacchia, M.

1987-03-01

A description is presented of the conceptual design of the 1 to 2 GeV Synchrotron Radiation Source proposed for construction at Lawrence Berkeley Laboratory. This facility is designed to produce ultraviolet and soft x-ray radiation. The accelerator complex consists of an injection system (linac plus booster synchrotron) and a low-emittance storage ring optimized for insertion devices. Eleven straight sections are available for undulators and wigglers, and up to 48 photon beam lines may ultimately emanate from bending magnets. Design features of the radiation source are the high brightness of the photon beams, the very short pulses (tens of picoseconds), and the tunability of the radiation

Black-body radiation of noncommutative gauge fields

International Nuclear Information System (INIS)

Fatollahi, Amir H.; Hajirahimi, Maryam

2006-01-01

The black-body radiation is considered in a theory with noncommutative electRomegnetic fields; that is noncommutativity is introduced in field space, rather than in real space. A direct implication of the result on cosmic microwave background map is argued

Radiation Testing at Sandia National Laboratories: Sandia – JPL Collaboration for Europa Lander

Energy Technology Data Exchange (ETDEWEB)

Hattar, Khalid Mikhiel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Ion Beam Lab.; Olszewska-Wasiolek, Maryla Aleksandra [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Gamma Irradiation Facility

2017-01-01

Sandia National Laboratories (SNL) is assisting Jet Propulsion Laboratory in undertaking feasibility studies and performance assessments for the Planetary Protection aspect of the Europa Lander mission. The specific areas of interest for this project are described by task number. This white paper presents the evaluation results for Task 2, Radiation Testing, which was stated as follows: Survey SNL facilities and capabilities for simulating the Europan radiation environment and assess suitability for: A. Testing batteries, electronics, and other component and subsystems B. Exposing biological organisms to assess their survivability metrics. The radiation environment the Europa Lander will encounter on route and in orbit upon arrival at its destination consists primarily of charged particles, energetic protons and electrons with the energies up to 1 GeV. The charged particle environments can be simulated using the accelerators at the Ion Beam Laboratory. The Gamma Irradiation Facility and its annex, the Low Dose Rate Irradiation Facility, offer irradiations using Co-60 gamma sources (1.17 and 1.33 MeV), as well as Cs-137 gamma (0.661 MeV) AmBe neutron (0-10 MeV) sources.

Characterization of an extrapolation chamber and radiochromic films for verifying the metrological coherence among beta radiation fields; Caracterizacao de uma camara de extrapolacao e filmes radiocromicos para verificacao da coerencia metrologica entre campos padroes de radiacao beta

Energy Technology Data Exchange (ETDEWEB)

Castillo, Jhonny Antonio Benavente

2011-07-01

The metrological coherence among standard systems is a requirement for assuring the reliability of dosimetric quantities measurements in ionizing radiation field. Scientific and technologic improvements happened in beta radiation metrology with the installment of the new beta secondary standard BSS2 in Brazil and with the adoption of the internationally recommended beta reference radiations. The Dosimeter Calibration Laboratory of the Development Center for Nuclear Technology (LCD/CDTN), in Belo Horizonte, implemented the BSS2 and methodologies are investigated for characterizing the beta radiation fields by determining the field homogeneity, the accuracy and uncertainties in the absorbed dose in air measurements. In this work, a methodology to be used for verifying the metrological coherence among beta radiation fields in standard systems was investigated; an extrapolation chamber and radiochromic films were used and measurements were done in terms of absorbed dose in air. The reliability of both the extrapolation chamber and the radiochromic film was confirmed and their calibrations were done in the LCD/CDTN in {sup 90}Sr/{sup 90}Y, {sup 85}Kr and {sup 147}Pm beta radiation fields. The angular coefficients of the extrapolation curves were determined with the chamber; the field mapping and homogeneity were obtained from dose profiles and isodose with the radiochromic films. A preliminary comparison between the LCD/CDTN and the Instrument Calibration Laboratory of the Nuclear and Energy Research Institute / Sao Paulo (LCI/IPEN) was carried out. Results with the extrapolation chamber measurements showed in terms of absorbed dose in air rates showed differences between both laboratories up to de -I % e 3%, for {sup 90}Sr/{sup 90}Y, {sup 85}Kr and {sup 147}Pm beta radiation fields, respectively. Results with the EBT radiochromic films for 0.1, 0.3 and 0.15 Gy absorbed dose in air, for the same beta radiation fields, showed differences up to 3%, -9% and -53%. The beta

Strain-induced modulation of near-field radiative transfer.

Science.gov (United States)

Ghanekar, Alok; Ricci, Matthew; Tian, Yanpei; Gregory, Otto; Zheng, Yi

2018-06-11

In this theoretical study, we present a near-field thermal modulator that exhibits change in radiative heat transfer when subjected to mechanical stress/strain. The device has two terminals at different temperatures separated by vacuum: one fixed and one stretchable. The stretchable side contains one-dimensional grating. When subjected to mechanical strain, the effective optical properties of the stretchable side are affected upon deformation of the grating. This results in modulation of surface waves across the interfaces influencing near-field radiative heat transfer. We show that for a separation of 100 nm, it is possible to achieve 25% change in radiative heat transfer for a strain of 10%.

Efficacy and safety of far infrared radiation in lymphedema treatment: clinical evaluation and laboratory analysis.

Science.gov (United States)

Li, Ke; Zhang, Zheng; Liu, Ning Fei; Feng, Shao Qing; Tong, Yun; Zhang, Ju Fang; Constantinides, Joannis; Lazzeri, Davide; Grassetti, Luca; Nicoli, Fabio; Zhang, Yi Xin

2017-04-01

Swelling is the most common symptom of extremities lymphedema. Clinical evaluation and laboratory analysis were conducted after far infrared radiation (FIR) treatment on the main four components of lymphedema: fluid, fat, protein, and hyaluronan. Far infrared radiation is a kind of hyperthermia therapy with several and additional benefits as well as promoting microcirculation flow and improving collateral lymph circumfluence. Although FIR therapy has been applied for several years on thousands of lymphedema patients, there are still few studies that have reported the biological effects of FIR on lymphatic tissue. In this research, we investigate the effects of far infrared rays on the major components of lymphatic tissue. Then, we explore the effectiveness and safety of FIR as a promising treatment modality of lymphedema. A total of 32 patients affected by lymphedema in stage II and III were treated between January 2015 and January 2016 at our department. After therapy, a significant decrease of limb circumference measurements was noted and improving of quality of life was registered. Laboratory examination showed the treatment can also decrease the deposition of fluid, fat, hyaluronan, and protein, improving the swelling condition. We believe FIR treatment could be considered as both an alternative monotherapy and a useful adjunctive to the conservative or surgical lymphedema procedures. Furthermore, the real and significant biological effects of FIR represent possible future applications in wide range of the medical field.

Leaching of wood ash - Laboratory and field studies; Lakning av vedaska - Laboratorie- och faeltstudier

Energy Technology Data Exchange (ETDEWEB)

Larsson, Per-Erik

2012-02-15

High forest production leads to diminishing amounts of base cations and micro nutrients in forest soils. This is due to uptake in, and harvest of, the trees. Losses can be compensated for by spreading stabilized wood ash on the forest ground, which means recycling of base cations and micro nutrients. Chemical composition of wood ash can easily be described by standard methods in the laboratory. However, this does not include the process of leaching in nature, such as which components and leaching rate for different compounds. During field conditions several factors are added, which are not available in the laboratory. After almost 10 years in the forest soils there still remains large quantities of the original product. Only 10-30 % of the wood ash products and 5 % of the lime product has been leached. In the laboratory study the leached amount was slightly larger, at the most 35 % for wood ash and 20 % for lime. Both studies indicate long time for weathering of the products in forest soils. Slower leaching rate from pellets of wood ash compared to leaching rate from crushed wood ash in the laboratory study is not verified by the field study. This indicates limited possibilities to control rates of leaching in the environment

Evaluation of Radiometers Deployed at the National Renewable Energy Laboratory's Solar Radiation Research Laboratory

Energy Technology Data Exchange (ETDEWEB)

Habte, Aron; Wilcox, Stephen; Stoffel, Thomas

2015-12-23

This study analyzes the performance of various commercially available radiometers used for measuring global horizontal irradiances and direct normal irradiances. These include pyranometers, pyrheliometers, rotating shadowband radiometers, and a pyranometer with fixed internal shading and are all deployed at the National Renewable Energy Laboratory's Solar Radiation Research Laboratory. Data from 32 global horizontal irradiance and 19 direct normal irradiance radiometers are presented. The radiometers in this study were deployed for one year (from April 1, 2011, through March 31, 2012) and compared to measurements from radiometers with the lowest values of estimated measurement uncertainties for producing reference global horizontal irradiances and direct normal irradiances.

Visualization research of 3D radiation field based on Delaunay triangulation

International Nuclear Information System (INIS)

Xie Changji; Chen Yuqing; Li Shiting; Zhu Bo

2011-01-01

Based on the characteristics of the three dimensional partition, the triangulation of discrete date sets is improved by the method of point-by-point insertion. The discrete data for the radiation field by theoretical calculation or actual measurement is restructured, and the continuous distribution of the radiation field data is obtained. Finally, the 3D virtual scene of the nuclear facilities is built with the VR simulation techniques, and the visualization of the 3D radiation field is also achieved by the visualization mapping techniques. It is shown that the method combined VR and Delaunay triangulation could greatly improve the quality and efficiency of 3D radiation field visualization. (authors)

Radiation dosimetry and standards at the austrian dosimetry laboratory

International Nuclear Information System (INIS)

Leitner, A.

1984-10-01

The Austrian Dosimetry Laboratory, established and operated in cooperation between the Austrian Research Center Seibersdorf and the Federal Office of Metrology and Surveying (Bundesamt and Eich- und Vermessungswesen) maintains the national primary standards for radiation dosimetry. Furthermore its tasks include routine calibration of dosemeters and dosimetric research. The irradiation facilities of the laboratory comprise three X-ray machines covering the voltage range from 5 kV to 420 kV constant potential, a 60 Co teletherapy unit, a circular exposure system for routine batch calibration of personnel dosemeters with four gamma ray sources ( 60 Co and 137 Cs) and a reference source system with six gamma ray sources ( 60 Co and 137 Cs). In addition a set of calibrated beta ray sources are provided ( 147 Pm, 204 Tl and 90 Sr). The dosimetric equipment consists of three free-air parallelplate ionization chambers serving as primary standards of exposure for the X-ray energy region, graphite cavity chambers with measured volume as primary standards for the gamma radiation of 137 Cs and 60 Co as well as different secondary standard ionization chambers covering the dose rate range from the natural background level up to the level of modern therapy accelerators. In addition for high energy photon and electron radiation a graphite calorimeter is provided as primary standard of absorbed dose. The principle experimental set-ups for the practical use of the standards are presented and the procedures for the calibration of the different types of dosemeters are described. (Author)

Effect of ultraviolet radiation on laboratory cultures of green algae and cyanobacteria

International Nuclear Information System (INIS)

Palffy, K.; Ordog, V.; Voros, L.

2004-01-01

Since the discovery of the ozone hole, an increasing amount of work has been devoted to measuring the impact of the UV-radiation on living organisms. In this point of view, algae as the primer producers of aquatic ecosystems, get to the central part of the interest. The aim of the study was to study the effect of ultraviolet radiation on laboratory cultures of green algae and cyanobacteria

Development of advanced radiation monitors for pulsed neutron fields

CERN Document Server

AUTHOR|(CDS)2081895

The need of radiation detectors capable of efficiently measuring in pulsed neutron fields is attracting widespread interest since the 60s. The efforts of the scientific community substantially increased in the last decade due to the increasing number of applications in which this radiation field is encountered. This is a major issue especially at particle accelerator facilities, where pulsed neutron fields are present because of beam losses at targets, collimators and beam dumps, and where the correct assessment of the intensity of the neutron fields is fundamental for radiation protection monitoring. LUPIN is a neutron detector that combines an innovative acquisition electronics based on logarithmic amplification of the collected current signal and a special technique used to derive the total number of detected neutron interactions, which has been specifically conceived to work in pulsed neutron fields. Due to its special working principle, it is capable of overcoming the typical saturation issues encountere...

Activity report of Synchrotron Radiation Laboratory 2005

International Nuclear Information System (INIS)

2006-11-01

Since 1980s, the Synchrotron Radiation Laboratory (SRL) has been promoting the 'Super-SOR' project, the new synchrotron radiation facility dedicated to sciences in vacuum ultraviolet and soft X-ray regions. The University of Tokyo considered the project as one of the most important future academic plans and strongly endorsed to construct the new facility with an electron storage ring of third generation type in the Kashiwa campus. During last year, the design of the accelerator system was slightly modified to obtain stronger support of the people in the field of bio-sciences, such as medicine, pharmacy, agriculture, etc. The energy of the storage ring was increased to 2.4 GeV, which is determined to obtain undulator radiation with sufficient brightness in X-ray region for the protein crystallography experiments. The value was also optimised to avoid considerable degradation of undulator radiation in the VUV and soft X-ray regions. However, in October last year, the president office of the University found out that the promotion of the project was very difficult for financial reasons. The budget for the new facility project is too big to be supported by a single university. The decision was intensively discussed by the International Review Committee on the Institute for Solid State Physics (ISSP), which was held at ISSP from November 14 to 16. The committee understood that the restructuring of the University system in Japan would overstrain the financial resources of the University of Tokyo and accepted the decision by the University. Presently, SRL has inclined to install beamlines using undulator radiation in other SR facilities instead of constructing a facility with a light source accelerator. At new beamlines, SRL will promote advanced materials sciences utilizing high brilliance and small emittance of synchrotron radiation which have been considered in the Super-SOR project. They are those such as microscopy and time-resolved experiments, which will only be

Radiative decay of coupled states in an external dc field

International Nuclear Information System (INIS)

Pal'chikov, V.; Sokolov, Y.; Yakovlev, V.

2001-01-01

This paper examines two theoretical aspects of the interference of atomic states in hydrogen which comes from the application of an external electric field F to the 2s metastable state. The radiative corrections to the Bethe-Lamb formula and anisotropy contribution to the angular distribution, which arises from interference between electric-field-induced E1-radiation and forbidden M1-radiation, are analysed

Radiative decay of coupled states in an external dc field

Energy Technology Data Exchange (ETDEWEB)

Pal' chikov, V. [National Research Inst. for Physical-Technical and Radiotechnical Measurements (VNIIFTRI), Mendeleevo, Moscow Region (Russian Federation); Sokolov, Y. [Kurchatov Inst., Russian Research Centre, Moscow (Russian Federation); Yakovlev, V. [Moscow Engineering Physics Inst., Moscow (Russian Federation)

2001-07-01

This paper examines two theoretical aspects of the interference of atomic states in hydrogen which comes from the application of an external electric field F to the 2s metastable state. The radiative corrections to the Bethe-Lamb formula and anisotropy contribution to the angular distribution, which arises from interference between electric-field-induced E1-radiation and forbidden M1-radiation, are analysed.

Evaluation of the Leon3 soft-core processor within a Xilinx radiation-hardened field-programmable gate array.

Energy Technology Data Exchange (ETDEWEB)

Learn, Mark Walter

2012-01-01

The purpose of this document is to summarize the work done to evaluate the performance of the Leon3 soft-core processor in a radiation environment while instantiated in a radiation-hardened static random-access memory based field-programmable gate array. This evaluation will look at the differences between two soft-core processors: the open-source Leon3 core and the fault-tolerant Leon3 core. Radiation testing of these two cores was conducted at the Texas A&M University Cyclotron facility and Lawrence Berkeley National Laboratory. The results of these tests are included within the report along with designs intended to improve the mitigation of the open-source Leon3. The test setup used for evaluating both versions of the Leon3 is also included within this document.

An example of remote maintenance in high radiation fields

International Nuclear Information System (INIS)

Pothier, N.E.; Brisbois, L.U.

Six auxiliary low pressure small (diameter <=5.0 cm) pipes located inside the reactor vault of the Douglas Point Nuclear Generating Station failed due to fretting wear at U-bolt supports: two had worn through the wall and developed leaks, and the others had worn <= 50% through the pipe wall. Human entry into the vault was not possible because of high radiation fields; hence, hands-on repair was not possible. The pipes were repaired and resupported to prevent further fretting wear failures during February-September, 1980. The repair work was performed using custom designed and developed remotely operated tooling and closed-circuit TV viewing. Three main groups were involved in the repair work: Atomic Energy of Canada Engineering Company (AECEC) - the reactor owner; Ontario Hydro - the reactor operator; and, Chalk River Nuclear Laboratories (CRNL). In this report, the contributions made by CRNL are summarized and discussed

Radiation protection in a multi-disciplinary research laboratory

International Nuclear Information System (INIS)

O'Donovan, E.J.B.; Jenks, G.J.; Brighton, D.R.

1993-01-01

This paper describes the measures for the protection of personnel against the hazards of ionising and non-ionising radiation at the Materials Research Laboratory (MRL) in Victoria. The paper describes MRL safety and protection policy and management, and gives brief details of procedures and problems at the working level. A comparison of MRL average annual photon doses with all Governmental Research Institutions and industry is given. The good safety record of MRL is evident and shows that the radioactive protection issues are well handled. 4 figs

Radiation and detection of gravitational waves in laboratory conditions

International Nuclear Information System (INIS)

Bogolyubov, P.N.; Pisarev, A.F.; Shavokhina, N.S.

1981-01-01

Two variants are proposed and analyzed for an experiment on radiation and detection of gravitational waves in laboratory conditions in the optical and superhigh frequency range (band). In the first variant the laser light is parametrically transformed to the gravitational wave in the optical-inhomogeneous medium. The gravitational flux produced is registered by the inverse parametric transformation of the gravitational to light wave. In the second variant the radiation of gravitational waves is realized through hypersonic oscillations in piezocrystals, and the reception of waves is made by the superconducting coaxial resonator in which the gravitational wave resonantly transforms into the electromag= . netic wave. The analysis performed testifies to the possibility of an experiment of this type at the present time [ru

Laboratory investigation of fire radiative energy and smoke aerosol emissions

Science.gov (United States)

Charles Ichoku; J. Vanderlei Martins; Yoram J. Kaufman; Martin J. Wooster; Patrick H. Freeborn; Wei Min Hao; Stephen Baker; Cecily A. Ryan; Bryce L. Nordgren

2008-01-01

Fuel biomass samples from southern Africa and the United States were burned in a laboratory combustion chamber while measuring the biomass consumption rate, the fire radiative energy (FRE) release rate (Rfre), and the smoke concentrations of carbon monoxide (CO), carbon dioxide (CO2), and particulate matter (PM). The PM mass emission rate (RPM) was quantified from...

Violin f-hole contribution to far-field radiation via patch near-field acoustical holography.

Science.gov (United States)

Bissinger, George; Williams, Earl G; Valdivia, Nicolas

2007-06-01

The violin radiates either from dual ports (f-holes) or via surface motion of the corpus (top+ribs+back), with no clear delineation between these sources. Combining "patch" near-field acoustical holography over just the f-hole region of a violin with far-field radiativity measurements over a sphere, it was possible to separate f-hole from surface motion contributions to the total radiation of the corpus below 2.6 kHz. A0, the Helmholtz-like lowest cavity resonance, radiated essentially entirely through the f-holes as expected while A1, the first longitudinal cavity mode with a node at the f-holes, had no significant f-hole radiation. The observed A1 radiation comes from an indirect radiation mechanism, induced corpus motion approximately mirroring the cavity pressure profile seen for violinlike bowed string instruments across a wide range of sizes. The first estimates of the fraction of radiation from the f-holes F(f) indicate that some low frequency corpus modes thought to radiate only via surface motion (notably the first corpus bending modes) had significant radiation through the f-holes, in agreement with net volume changes estimated from experimental modal analysis. F(f) generally trended lower with increasing frequency, following corpus mobility decreases. The f-hole directivity (top/back radiativity ratio) was generally higher than whole-violin directivity.

Field and laboratory tests on acute toxicity of cadmium to freshwater crayfish

Energy Technology Data Exchange (ETDEWEB)

1986-09-01

Environmental regulatory standards for cadmium (EPA 1980), like those for most pollutants, are based on acute, laboratory toxicity tests of single species. Such tests can be conducted rapidly and inexpensively in comparison to acute or chronic field studies, but their validity has often been questioned. Laboratory-based criteria are subject to two criticisms: (1) chemical and physical conditions differ greatly in degree and variability from laboratory to field, and (2) species are not isolated, but live in an ecosystem of interacting taxa and biofeedback. To investigate the validity of basing field toxicity standards on laboratory data, the authors subjected the freshwater crayfish Orconectes immunis for 96 h to various levels of cadmium in laboratory aquaria and experimental ponds. The study was designed to evaluate in part the first criticism of lab-based criteria. The studies were conducted concurrently with similar short-term experiments on the fathead minnow, Pimephales promelas, and coincided with studies of chronic cadmium stress on fathead minnows in experimental ponds.

HESYRL: a dedicated synchrotron radiation laboratory in China

International Nuclear Information System (INIS)

Qiu, L.J.

1985-01-01

The HESYRL national synchrotron radiation laboratory was first proposed in 1977 as a conclusion of a general planning meeting on nationwide development of natural science and technology at which a topic was the application of synchrotron radiation. A study group was formed in 1978 to carry out preliminary research and prototype development work. The final approval of the project was given in April 1983 and the lab was soon founded. Designs of the main facilities and building completed in Oct 1984. The ground breaking was in Nov 1984. Manufacturing and purchasing of all the equipment and components are now in progress. The overall layout of HESYRL project is shown. the main facilities are an 800 MeV electron storage ring, a 88 meter transport line and a 240 MeV linac as the injector. Some basic considerations in the selecting of major machine parameters are discussed

Standards for radiation protection and diagnostic radiology at the IAEA Dosimetry Laboratory

International Nuclear Information System (INIS)

Pernicka, F.; Andreo, P.; Meghzifene, A.; Czap, L.; Girzikowsky, R.

1999-01-01

International standardization in dosimetry is essential for the successful exploitation of radiation technology. The IAEA dosimetry programme is focused into services provided to Member States through the IAEA/WHO Network of Secondary Standard Dosimetry Laboratories (SSDLs), to radiotherapy centres and radiation processing facilities. Radiation protection quantities defined by ICRU and ICRP are used to relate the risk due to exposure to ionizing radiation to a single quantity, irrespective of the type of radiation, which takes into account the human body as a receptor. Two types of quantities, limiting and operational, can be related to basic physical quantities which are defined without need for considering specific aspects of radiation protection, e.g. air kerma for photons and fluence for neutrons. The use of a dosimeter for measurements in radiation protection requires a calibration in terms of a physical quantity together with a conversion from physical into protection quantities by means of a factor or a coefficient

Radiation distribution sensor with optical fibers for high radiation fields

International Nuclear Information System (INIS)

Takada, Eiji; Kimura, Atsushi; Hosono, Yoneichi; Takahashi, Hiroyuki; Nakazawa, Masaharu

1999-01-01

Radiation distribution sensors with their feasibilities have been described in earlier works. However, due to large radiation induced transmission losses in optical fibers, especially in the visible wavelength region, it has been difficult to apply these techniques to high radiation fields. In this study, we proposed a new concept of optical fiber based radiation distribution measurements with near infrared (IR) emission. Near IR scintillators were attached to the ends of optical fibers, where the fibers were bundled and connected to an N-MOS line sensor or a cooled CCD camera. From the measurements of each area density, the radiation levels at the positions of the scintillators can be known. The linearity between the gamma dose rate at each scintillator and the registered counts has been examined. For correcting the radiation induced loss effects, we applied the Optical Time Domain Reflectometry technique to measure the loss distribution and from the results, a possibility for correction of the loss effect has been demonstrated. The applicable dose rate range was evaluated to be from 0.1 to 10 3 Gy/h. This system can be a promising tool as a flexible dose rate distribution monitor in radiation facilities like nuclear plants and accelerator facilities. (author)

A Coastal Environment Field and Laboratory Activity for an Undergraduate Geomorphology Course

Science.gov (United States)

Ellis, Jean T.; Rindfleisch, Paul R.

2006-01-01

A field and laboratory exercise for an undergraduate geomorphology class is described that focuses on the beach. The project requires one day of fieldwork and two laboratory sessions. In the field, students measure water surface fluctuations (waves) with a pressure sensor, survey beach profiles, collect sediment samples, and observe the beach…

The role of the IAEA Dosimetry Laboratory in the dissemination of standards for radiation protection

International Nuclear Information System (INIS)

Czap, L.; Andreo, P.; Matscheko, G.

1998-01-01

Approximately 90% of the Secondary Standard Dosimetry Laboratories (SSDLs) provide users with calibrations of radiation protection instruments, and the IAEA is taking every necessary effort to insure that SSDLs measurements are traceable to Primary Standards. The Agency has proper radiation sources available to provide traceable calibrations to the SSDLs involved in measurements on diagnostic x-ray generators, including an x-ray unit specifically for mammography dedicated to standardization procedures. The different photon beam qualities and calibration procedures available in the Agency's Dosimetry Laboratory are described

Fiber optics in high dose radiation fields

International Nuclear Information System (INIS)

Partin, J.K.

1985-01-01

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

Formation of comets by radiation pressure in the outer protosun. III. Dependence on the anisotropy of the radiation field

International Nuclear Information System (INIS)

Hills, J.G.; Sandford, M.T. Jr.

1983-01-01

A two-dimensional, radiation-hydrodynamic code with dust was used to study the effect of an anisotropic radiation field on the formation of comets in the outer protosun by the radiation pressure from the Sun and surrounding protostars. If the radiation field is isotropic, the results are very similar to those found earlier by analytic models. When the dust cloud is flanked on two sides by luminous walls of equal strength but with no radiation entering the cloud from the azimuthal direction (a radiation vise), most of the dust eventually squeezes out the sides of the vise. The sides are open to outward streaming radiation which carries the dust with it. However, the entrance of even a small amount of radiation from the sides causes the dust to drift inward to form the comet. The work given in this paper indicates that a highly anisotropic radiation field is not likely to prevent the formation of a comet. It distorts the shape of the inward drifting dust cloud. Initially, faster inward drift occurs along radii having the strongest inward radiation flux. This in turn causes the optical depth to increase faster along the perpendicular radii where the radiation field is the weakest. The increase in the optical depth eventually compensates for the low radiation flux, so as the cloud shrinks the radiation pressure increases faster at the surface of the cloud along those radius vectors where the radiation flux has a minimum. Although the dust cloud in the anisotropic radiation field attains a very irregular shape, eventually all parts of the cloud contract in unison and arrive at the center of the cloud at about the same time

Maximal near-field radiative heat transfer between two plates

Science.gov (United States)

Nefzaoui, Elyes; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

2013-09-01

Near-field radiative transfer is a promising way to significantly and simultaneously enhance both thermo-photovoltaic (TPV) devices power densities and efficiencies. A parametric study of Drude and Lorentz models performances in maximizing near-field radiative heat transfer between two semi-infinite planes separated by nanometric distances at room temperature is presented in this paper. Optimal parameters of these models that provide optical properties maximizing the radiative heat flux are reported and compared to real materials usually considered in similar studies, silicon carbide and heavily doped silicon in this case. Results are obtained by exact and approximate (in the extreme near-field regime and the electrostatic limit hypothesis) calculations. The two methods are compared in terms of accuracy and CPU resources consumption. Their differences are explained according to a mesoscopic description of nearfield radiative heat transfer. Finally, the frequently assumed hypothesis which states a maximal radiative heat transfer when the two semi-infinite planes are of identical materials is numerically confirmed. Its subsequent practical constraints are then discussed. Presented results enlighten relevant paths to follow in order to choose or design materials maximizing nano-TPV devices performances.

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2014-01-24

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

Study on quantities of radiation protection in medical X-rays radiation field with polyhedron phantom

International Nuclear Information System (INIS)

Yuan Shuyu; Dai Guangfu; Zhang Liangan

1997-01-01

The author have studied tissue-equivalent material with the elemental composition recommended by report No.44 of ICRU. Three different calibration phantoms in shape have been prepared with the tissue-equivalent material in order to study the influence of the angular dependence factor R(d,α) in the radiation field of X-rays on the calibration of individual dose equivalent Hp(d). The requirement of mono-genous radiation field to calibrate several dosimeters on one phantom at the same time can be met by application of dodecahedron phantom, which is difficult on ICRU sphere. Angular dependence factor R(d,α) of 0 degree∼90 degree and conversion coefficients between individual dose equivalent Hp(0.07, α) and the exposure of radiation of different energies and different angles have been established by taking advantage of the dodecahedron. Besides, the authors have studied the variation relation between the individual dose equivalent Hp (10,α) and Hp(0.07,α) in the medical X-rays radiation field

Combination transition radiation in a medium excited by an electromagnetic field

International Nuclear Information System (INIS)

Kalashnikova, Yu.S.

1976-01-01

The radiation emitted by a uniformly moving charged particle in a medium excited by an electromagnetic field is considered by taking into account the interaction between the electromagnetic waves and optical phonon wave. The frequencies are found, in the vicinity of which the two-wave approximation should be applied in order to determine the radiation field. It is shown that in the vicinity of these frequencies the radiation considerably differs from the Cherenkov radiation

Annual report of the Osaka Laboratory for Radiation Chemistry Japan Atomic Energy Research Institute, 21

International Nuclear Information System (INIS)

1990-03-01

This report describes research activities of Osaka Laboratory for Radiation Chemistry, JAERI during one year period from April 1, 1987 through March 31, 1988. Detailed descriptions of the activities are presented in the following subjects: (i) studies on surface phenomena under electron and ion irradiations and (ii) studies on radiation chemistry of high polymers and radiation dosimetry. (J.P.N.)

Problems with ink skin markings for radiation field setups

International Nuclear Information System (INIS)

Endoh, Masaru; Saeki, Mituaki; Ishida, Yusei

1982-01-01

Ink skin markings are used in radiation therapy to aid in reproduction of treatment field setups or to indelibly outline field markings or tumors. We reported two cases of indelible ink skin for radiation field septa with minimal discomfort and dermatitis have been experienced for 6 months and above since end of radiotherapy. These indelible ink skin markings look like tattoo that will be big problems in the case of young female. We improved these problems by using of 10 percent silver nitrate instead of habitual skin ink. (author)

Laboratory contamination in the early period of radiation research

International Nuclear Information System (INIS)

Rona, E.

1979-01-01

Meagre records exist of the levels of contamination and human exposure encountered by those who took part in the early research on radioactive materials. In order to throw some light on the nature and extent of the problem the author presents some recollections of the conditions of the laboratories in which she worked from 1924-1940. These include the Kaiser Wilhelm Institute, the Radium Institute of Vienna and the Curie Institute. The health, radiation injuries and causes of death of some early workers are discussed. Although the effects of acute exposure were recognised early on, there was less awareness of the possible effects of chronic exposure, and lack of prompt clinical signs of injury encouraged complacency. Laboratory contamination was often seen more as a problem affecting experimental results than as a health hazard. (author)

Comparative Studies on the Bioretention of Radionuclides under Laboratory and Field Conditions

International Nuclear Information System (INIS)

Heyraud, M.; Fowler, S.W.

1976-01-01

The influence of different sea water treatments on radio-isotope flux rates was tested in three species. For any one species no significant differences in 65 Zn loss rate were noted between organisms held in sea water collected in situ and in those maintained in sea water from the laboratory system. Increased sea water zinc concentration accelerated 65 Zn flux rates; however, the more rapid 65 Zn loss compared to that measured in control sea water was only significant when the concentration was increased by 100μg zinc/liter. Simultaneous laboratory and field experiments indicated that loss rates in clams and mussels were similar whether animals were held in the field or in the laboratory. Experiments in which crabs were monitored for 65 Zn loss gave conflicting results. One experiment performed during the summer indicated that crabs lost 65 Zn significantly faster in the laboratory than in the field. Another experiment performed during the winter when water temperatures were lower indicated no differences in loss rates between the two systems. Differences in radioisotope flux rate may have been related to the intermolt cycle; nevertheless, it was concluded that for certain organisms care should be exercised when applying results of laboratory experiments to the field situation. (author)

1994 activity report: Stanford Synchrotron Radiation Laboratory

International Nuclear Information System (INIS)

Cantwell, K.; Dunn, L.

1994-01-01

The SSRL facility delivered 89% of the scheduled user beam to 25 experimental stations during 6.5 months of user running. Users from private industry were involved in 31% of these experiments. The SPEAR accelerator ran very well with no major component failures and an unscheduled down time of only 2.9%. In addition to this increased reliability, there was a significant improvement in the stability of the beam. The enhancements to the SPEAR orbit as part of a concerted three-year program were particularly noticeable to users. The standard deviation of beam movement (both planes) in the last part of the run was 80 microns, major progress toward the ultimate goal of 50-micron stability. This was a significant improvement from the previous year when the movement was 400 microns in the horizontal and 200 microns in the vertical. A new accelerator Personal Protection System (PPS), built with full redundancy and providing protection from both radiation exposure and electrical hazards, was installed in 1994. It is not possible to describe in this summary all of the scientific experimentation which was performed during the run. However, the flavor of current research projects and the many significant accomplishments can be realized by the following highlights: A multinational collaboration performed several experiments involving x-ray scattering from nuclear resonances; Studies related to nuclear waste remediation by groups from Los Alamos National Laboratory and Pacific Northwest Laboratories continued in 1994; Diffraction data sets for a number of important protein crystals were obtained; During the past two years a collaboration consisting of groups from Hewlett Packard, Intel, Fisons Instruments and SSRL has been exploring the utility of synchrotron radiation for total reflection x-ray fluorescence (TRXRF); and High-resolution angle-resolved photoemission experiments have continued to generate exciting new results from highly correlated and magnetic materials

1994 activity report: Stanford Synchrotron Radiation Laboratory

Energy Technology Data Exchange (ETDEWEB)

Cantwell, K.; Dunn, L. [eds.

1994-01-01

The SSRL facility delivered 89% of the scheduled user beam to 25 experimental stations during 6.5 months of user running. Users from private industry were involved in 31% of these experiments. The SPEAR accelerator ran very well with no major component failures and an unscheduled down time of only 2.9%. In addition to this increased reliability, there was a significant improvement in the stability of the beam. The enhancements to the SPEAR orbit as part of a concerted three-year program were particularly noticeable to users. The standard deviation of beam movement (both planes) in the last part of the run was 80 microns, major progress toward the ultimate goal of 50-micron stability. This was a significant improvement from the previous year when the movement was 400 microns in the horizontal and 200 microns in the vertical. A new accelerator Personal Protection System (PPS), built with full redundancy and providing protection from both radiation exposure and electrical hazards, was installed in 1994. It is not possible to describe in this summary all of the scientific experimentation which was performed during the run. However, the flavor of current research projects and the many significant accomplishments can be realized by the following highlights: A multinational collaboration performed several experiments involving x-ray scattering from nuclear resonances; Studies related to nuclear waste remediation by groups from Los Alamos National Laboratory and Pacific Northwest Laboratories continued in 1994; Diffraction data sets for a number of important protein crystals were obtained; During the past two years a collaboration consisting of groups from Hewlett Packard, Intel, Fisons Instruments and SSRL has been exploring the utility of synchrotron radiation for total reflection x-ray fluorescence (TRXRF); and High-resolution angle-resolved photoemission experiments have continued to generate exciting new results from highly correlated and magnetic materials.

Field and Laboratory Tests of Chromium-51-EDTA and Tritium Water as a Double Tracer for Groundwater Flow

International Nuclear Information System (INIS)

Knutsson, G.; Uunggren, K.; Forsberg, H. G.

1963-01-01

Since 1958 field experiments and laboratory tests have been made in a study of groundwater flow in different geological and mineralogical environments by the use of gamma-emitting tracers ana tritium water. The velocity of groundwater flow in soil is rather low, and tracers with medium or long half-life must be chosen to trace the movement. A stable EDTA-complex of Cr 51 (half-life 28 d) was developed for this purpose and used together with tritium water. With this double tracer it was possible to follow the groundwater flow by measurement of the gamma radiation from Cr 51 directly in the field and thereby to reduce the number of water samples for precise laboratory assessment. By comparison of the measured activities of Cr 51 and tritium it was possible to determine whether there was any retardation or loss of the chromium complex as a result of adsorption. Six field investigations, each of about two months' duration, have been made in glacifluvial sand and gravel. The results from these show that the chromium complex is transported as rapidly as the tritium water is, even at low concentrations (0. 01 ppm) of the complex. 17 field investigations of one to three months' duration with this double tracer have been carried out in various till (moraine) soils for a study of certain hydrological problems. Laboratory tests with soil and water from the various areas of field investigations have shown that the chromium complex does not hydrolyse at concentrations above 0.01 ppm. Further laboratory tests of the reliability of the chromium complex in different mineralogical environments are in progress. A number of investigations of groundwater flow through fissures and channels have abo been made. When the velocity of flow was assumed to be very high, Br 82 as bromide ion or Rhodamine-B, a fluorescent organic dye, were used. EDTA-Cr 51 and tritium water were, however, used when the velocity was considered low or when, as in karst, a great number of channels or large

A reappraisal of the reported dose equivalents at the boundary of the University of California Radiation Laboratory during the early days of Bevatron operation

International Nuclear Information System (INIS)

Thomas, Ralph H.; Smith, Alan R.; Zeman, Gary H.

2000-01-01

Accelerator-produced radiation levels at the perimeter of the Ernest Orlando Lawrence Berkeley National Laboratory (the Berkeley Laboratory) reached a maximum in 1959. Neutrons produced by the Bevatron were the dominant component of the radiation field. Radiation levels were estimated from measurements of total neutron fluence and reported in units of dose equivalent (rem). Accurate conversion from total fluence to dose equivalent demands knowledge of both the energy spectrum of accelerator-produced neutrons and the appropriate conversion coefficient functions for different irradiation geometries. At that time (circa 1960), such information was limited, and it was necessary to use judgment in the interpretation of measured data. The Health Physics Group of the Berkeley Laboratory used the best data then available and, as a matter of policy, reported the most conservative (largest) values of dose equivalent supported by their data. Since the early sixties, significant improvements in the information required to compute dose equivalent, particularly in the case of conversion coefficients, have been reported in the scientific literature. This paper reinterprets the older neutron measurements using the best conversion coefficient data available today. It is concluded that the dose equivalents reported in the early sixties would be reduced by at least a factor of two using current methods of analysis

Active Radiation Level Measurement on New Laboratory Instrument for Evaluating the Antibacterial Activity of Radioisotope

International Nuclear Information System (INIS)

Joh, Eunha; Park, Jang Guen

2014-01-01

A disc method has been widely used to measure the antibacterial effect of chemical agents. However, it is difficult to measure the antibacterial effect of radioisotopes using a disc method. A disc method is a method for diffusing a drug by placing the drug containing disc on the medium. In this method, radioisotopes are diffused on the medium and it is difficult to measure the exact effect by radiation. Thus, new laboratory equipment needs to evaluate the antibacterial activity by the radioisotopes. In this study, we measured the radiation level of radioisotopes on a new laboratory instrument using a MCNP. A disc method has been widely used to measure the antibacterial effect of chemical agents. This method uses a drug diffusion system for the measurement of anti-bacterial antibiotics. To measure the antimicrobial activity of a radioisotope, a new type of laboratory instrument is necessary to prevent the drug from spreading. The radioisotopes are used to diagnose and treat cancer. However, studies for anti-biotical use have not progressed. The radiation of radioisotopes has the effect of killing bacteria. Before this study proceeds further, it is necessary to be able to measure the antimicrobial activity of the radioisotope easily in the laboratory. However, in this study, it was possible to measure the antimicrobial activity of the radioisotope in the laboratory using a new laboratory instrument. We intend to start evaluation studies of the antibacterial activity of specific radioisotopes. In addition, it will be possible to develop research to overcome diseases caused by bacteria in the future

Active Radiation Level Measurement on New Laboratory Instrument for Evaluating the Antibacterial Activity of Radioisotope

Energy Technology Data Exchange (ETDEWEB)

Joh, Eunha; Park, Jang Guen [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

A disc method has been widely used to measure the antibacterial effect of chemical agents. However, it is difficult to measure the antibacterial effect of radioisotopes using a disc method. A disc method is a method for diffusing a drug by placing the drug containing disc on the medium. In this method, radioisotopes are diffused on the medium and it is difficult to measure the exact effect by radiation. Thus, new laboratory equipment needs to evaluate the antibacterial activity by the radioisotopes. In this study, we measured the radiation level of radioisotopes on a new laboratory instrument using a MCNP. A disc method has been widely used to measure the antibacterial effect of chemical agents. This method uses a drug diffusion system for the measurement of anti-bacterial antibiotics. To measure the antimicrobial activity of a radioisotope, a new type of laboratory instrument is necessary to prevent the drug from spreading. The radioisotopes are used to diagnose and treat cancer. However, studies for anti-biotical use have not progressed. The radiation of radioisotopes has the effect of killing bacteria. Before this study proceeds further, it is necessary to be able to measure the antimicrobial activity of the radioisotope easily in the laboratory. However, in this study, it was possible to measure the antimicrobial activity of the radioisotope in the laboratory using a new laboratory instrument. We intend to start evaluation studies of the antibacterial activity of specific radioisotopes. In addition, it will be possible to develop research to overcome diseases caused by bacteria in the future.

Maximal near-field radiative heat transfer between two plates

OpenAIRE

Nefzaoui, Elyes; Ezzahri, Younès; Drevillon, Jérémie; Joulain, Karl

2013-01-01

International audience; Near-field radiative transfer is a promising way to significantly and simultaneously enhance both thermo-photovoltaic (TPV) devices power densities and efficiencies. A parametric study of Drude and Lorentz models performances in maximizing near-field radiative heat transfer between two semi-infinite planes separated by nanometric distances at room temperature is presented in this paper. Optimal parameters of these models that provide optical properties maximizing the r...

Radiation safety and quality control in the cyclotron laboratory

International Nuclear Information System (INIS)

Sharma, S.; Krause, G.; Ebadi, M.

2006-01-01

Radiation safety was determined to maintain quality control in the cyclotron laboratory. Based on the results of 438 runs in the Faraday cup (20 μA for 10 min), 20 runs on 18 O-water target (40 μA for 2 h) and 10 runs on 18 O-gas targets (30 μA for 45 min), we have established that occupationally exposed workers remain 10 ± 5 times below federal regulatory limits (FRLs) in the cyclotron vault, 30 ± 8 times below FRL in the radiochemistry laboratory and 200 ± 10 times below the FRL outside the cyclotron laboratory during beam operation. (The FRL for unrestricted area are <20 μSv in 1 h.) The non-occupationally exposed workers serving in offices in the vicinity of the cyclotron vault within 100 m distance remained 200 times below the FRL irrespective of beam being on or off, suggesting that routine beam operation of 40 μA for 2 h once a day during office hours is safe provided quality control and system performance measures as discussed in this report are strictly maintained. (authors)

Hawking radiation of five-dimensional charged black holes with scalar fields

Directory of Open Access Journals (Sweden)

Yan-Gang Miao

2017-09-01

Full Text Available We investigate the Hawking radiation cascade from the five-dimensional charged black hole with a scalar field coupled to higher-order Euler densities in a conformally invariant manner. We give the semi-analytic calculation of greybody factors for the Hawking radiation. Our analysis shows that the Hawking radiation cascade from this five-dimensional black hole is extremely sparse. The charge enhances the sparsity of the Hawking radiation, while the conformally coupled scalar field reduces this sparsity.

Remote Laboratory and Animal Behaviour: An Interactive Open Field System

Science.gov (United States)

Fiore, Lorenzo; Ratti, Giovannino

2007-01-01

Remote laboratories can provide distant learners with practical acquisitions which would otherwise remain precluded. Our proposal here is a remote laboratory on a behavioural test (open field test), with the aim of introducing learners to the observation and analysis of stereotyped behaviour in animals. A real-time video of a mouse in an…

Spherical-wave expansions of piston-radiator fields.

Science.gov (United States)

Wittmann, R C; Yaghjian, A D

1991-09-01

Simple spherical-wave expansions of the continuous-wave fields of a circular piston radiator in a rigid baffle are derived. These expansions are valid throughout the illuminated half-space and are useful for efficient numerical computation in the near-field region. Multipole coefficients are given by closed-form expressions which can be evaluated recursively.

Classical calculation of radiative lifetimes of atomic hydrogen in a homogeneous magnetic field

International Nuclear Information System (INIS)

Horbatsch, M.W.; Hessels, E.A.; Horbatsch, M.

2005-01-01

Radiative lifetimes of hydrogenic atoms in a homogeneous magnetic field of moderate strength are calculated on the basis of classical radiation. The modifications of the Keplerian orbits due to the magnetic field are incorporated by classical perturbation theory. The model is complemented by a classical radiative decay calculation using the radiated Larmor power. A recently derived highly accurate formula for the transition rate of a field-free hydrogenic state is averaged over the angular momentum oscillations caused by the magnetic field. The resulting radiative lifetimes for diamagnetic eigenstates classified by n,m and the diamagnetic energy shift C compare well with quantum results

New developments in pulsed fields at the US National High Magnetic Field Laboratory

International Nuclear Information System (INIS)

Campbell, L.J.; Parkin, D.M.; Rickel, D.G.; Pernambuco-Wise, P.

1996-01-01

Los Alamos National Laboratory is a member of a consortium (with Florida State University and the University of Florida) to operate the National High Magnetic Field Laboratory (NHMFL), with funding from the National Science Foundation and the State of Florida. Los Alamos provides unique resources for its component of NHMFL in the form of a 1.4 GW inertial storage motor-generator for high field pulsed magnets and infrastructure for fields generated by flux compression. The NHMFL provides a user facility open to all qualified users, develops magnet technology in association with the private sector, and advances science and technology opportunities. The magnets in service at Los Alamos are of three types. Starting with the pre-existing explosive flux compression capability in 1991, NHMFL added capacitor-driven magnets in December, 1992, and a 20 tesla superconducting magnet in January, 1993. The capacitor-driven magnets continue to grow in diversity and accessibility, with four magnet stations now available for several different magnet types. Two magnets of unprecedented size and strength are nearing completion of assembly and design, respectively. Under final assembly is a quasi-continuous magnet that contains 90 MJ of magnetic energy at full field, and being designed is a non-destructive 100 T magnet containing 140 MJ

Upper bound of abutment scour in laboratory and field data

Science.gov (United States)

Benedict, Stephen

2016-01-01

The U.S. Geological Survey, in cooperation with the South Carolina Department of Transportation, conducted a field investigation of abutment scour in South Carolina and used those data to develop envelope curves that define the upper bound of abutment scour. To expand on this previous work, an additional cooperative investigation was initiated to combine the South Carolina data with abutment scour data from other sources and evaluate upper bound patterns with this larger data set. To facilitate this analysis, 446 laboratory and 331 field measurements of abutment scour were compiled into a digital database. This extensive database was used to evaluate the South Carolina abutment scour envelope curves and to develop additional envelope curves that reflected the upper bound of abutment scour depth for the laboratory and field data. The envelope curves provide simple but useful supplementary tools for assessing the potential maximum abutment scour depth in the field setting.

A proposal how to take into account inhomogeneous radiation fields in radiation protection

International Nuclear Information System (INIS)

Tschurlovits, M.

1996-01-01

External radiation fields exposing the human body inhomogenously are not considered neither in radiation protection standards nor in recent ICRU recommendations, but appear frequently in practical radiation protection. A proposal to solve this question is given taking into account both a conceptual and a metrological approach. The proposal suggests that a mean over an area of about 100 cm 2 can be taken as reference area for compliance with limits in terms of effective dose. (author)

Safety Study of the X-Ray Reference Laboratory for Radiation Protection Levels (IR-14D)

International Nuclear Information System (INIS)

Garcia, G.

1999-01-01

This report is a study about the safety of the X-ray reference laboratory that has been recently constructed in the building 2 of the CIEMAT. After a brief description of the apparatus, we present the method used to calculate the exposure and absorbed dose rates in the most characteristic points of the laboratory. This method takes into account the spectral distribution of the radiation beams as a function of the accelerating voltage. The built-up factors of the absorbent materials have been considered to calculate the transmission of the radiation beams through the filters and shielding. Scattered radiations has been introduced in the calculations by means of a semiempirical method. This model supposes that multiple scattering processes give an isotropic contribution to the reflected beams and the single scattered can be described in terms of the differential cross section of Klein-Nishina. The results of this study have been applied to determine the maximum dose equivalent that the personnel of the laboratory could receive in normal operation conditions. (Author) 5 refs

DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009-2016

Science.gov (United States)

Berger, Thomas; Burmeister, Sönke; Matthiä, Daniel; Przybyla, Bartos; Reitz, Günther; Bilski, Pawel; Hajek, Michael; Sihver, Lembit; Szabo, Julianna; Ambrozova, Iva; Vanhavere, Filip; Gaza, Ramona; Semones, Edward; Yukihara, Eduardo G.; Benton, Eric R.; Uchihori, Yukio; Kodaira, Satoshi; Kitamura, Hisashi; Boehme, Matthias

2017-03-01

The natural radiation environment in Low Earth Orbit (LEO) differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR), as well as of protons and electrons trapped in the Earth's radiation belts (Van Allen belts). Protons and some heavier particles ejected in occasional Solar Particle Events (SPEs) might in addition contribute to the radiation exposure in LEO. All sources of radiation are modulated by the solar cycle. During solar maximum conditions SPEs occur more frequently with higher particle intensities. Since the radiation exposure in LEO exceeds exposure limits for radiation workers on Earth, the radiation exposure in space has been recognized as a main health concern for humans in space missions from the beginning of the space age on. Monitoring of the radiation environment is therefore an inevitable task in human spaceflight. Since mission profiles are always different and each spacecraft provides different shielding distributions, modifying the radiation environment measurements needs to be done for each mission. The experiments "Dose Distribution within the ISS (DOSIS)" (2009-2011) and "Dose Distribution within the ISS 3D (DOSIS 3D)" (2012-onwards) onboard the Columbus Laboratory of the International Space Station (ISS) use a detector suite consisting of two silicon detector telescopes (DOSimetry TELescope = DOSTEL) and passive radiation detector packages (PDP) and are designed for the determination of the temporal and spatial variation of the radiation environment. With the DOSTEL instruments' changes of the radiation composition and the related exposure levels in dependence of the solar cycle, the altitude of the ISS and the influence of attitude changes of the ISS during Space Shuttle dockings inside the Columbus Laboratory have been monitored. The absorbed doses measured at the end of May 2016 reached up to 286 �

Pacific Northwest Laboratory plan to maintain radiation exposure as low as reasonably achievable (ALARA)

International Nuclear Information System (INIS)

Higby, D.P.; Denovan, J.T.

1982-12-01

This document describes the radiation safety program at the Pacific Northwest Laboratory (PNL). The practices and administrative policies of this program support the principles of ALARA (to maintain radiation exposure as low as reasonably achievable). This document also describes a program to establish safety goals at PNL to help ensure that operations are conducted according to ALARA principles

Experimental comparison among the laboratories accredited within the framework of the European Co-operation for Accreditation on the calibration of a radiation protection dosimeters in the terms of the quantity air Kerma

International Nuclear Information System (INIS)

Bovi, M.; Toni, M.P.; Tricomi, G.

2002-01-01

The European co-operation for Accreditation (EA) formalises the collaboration of the Accreditation Bodies of the Member States of the European Union and the European Free Trade Association covering all conformity assessment activities. This collaboration is based on a Memorandum of Understanding dated the 27 November 1997 and aims at developing and maintain Multilateral Agreements (MLAs) within EA and with non-members accreditation bodies. MLAs Signatories guarantee uniformity of accreditation by continuous and rigorous evaluation. Based on mutual confidence, the MLAs recognise the equivalence of the accreditation systems administered by EA Members and of certificates and reports issued by bodies accredited under these systems. A basic element of the program to establish and maintain mutual confidence among calibration services is the participation of the accredited laboratories in experimental interlaboratory comparisons (ILC) organised by EA members or other international organisations. The aim of these ILC is to verify the technical equivalence of calibration services within the EA. The ILC which it is dealt with in the present work was recently carried out over a period of two years, ending in May 2002. It interested the laboratories accredited in the ionising radiation field for calibration of dosimeters at radiation protection levels in terms of the quantity air kerma (K air ) due to 6 0C o and 1 37C s gamma radiation. The ILC was planned by the EA expert group on Ionising radiation and radioactivity and approved by the EA General Assembly in December 1999 with the title Calibration of a Radiation Protection Dosimeter under the code IR3. The need of this comparison also resulted from an inquiry carried out in 1998 by the expert group among the different Accreditation Bodies members of EA and associated to EA. The organization of the ILC was carried out according to the EA rules by the Italian Accreditation Body in the ionising radiation field, the SIT

National Laboratory of Ionizing Radiation Metrology - Brazilian CNEN; Laboratorio Nacional de Metrologia das Radiacoes Ionizantes

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-12-31

The activities of the Brazilian National Laboratory of Ionizing Radiations Metrology are described. They include research and development of metrological techniques and procedures, the calibration of area radiation monitors, clinical dosemeters and other instruments and the preparation and standardization of reference radioactive sources. 4 figs., 13 tabs.

National Laboratory of Ionizing Radiation Metrology - Brazilian CNEN; Laboratorio Nacional de Metrologia das Radiacoes Ionizantes

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-12-31

The activities of the Brazilian National Laboratory of Ionizing Radiations Metrology are described. They include research and development of metrological techniques and procedures, the calibration of area radiation monitors, clinical dosemeters and other instruments and the preparation and standardization of reference radioactive sources. 4 figs., 13 tabs.

The Role of Laboratory Experiments in the Validation of Field Data

DEFF Research Database (Denmark)

Mouneyrac, Catherine; Lagarde, Fabienne; Chatel, Amelie

2017-01-01

The ubiquitous presence and persistency of microplastics (MPs) in aquatic environments are of particular concern, since they constitute a potential threat to marine organisms and ecosystems. However, evaluating this threat and the impacts of MP on aquatic organisms is challenging. MPs form a very...... and to what degree these complexities are addressed in the current literature, to: (1) evaluate how well laboratory studies, investigated so far, represent environmentally relevant processes and scenarios and (2) suggest directions for future research The Role of Laboratory Experiments in the Validation...... of Field Data | Request PDF. Available from: https://www.researchgate.net/publication/310360438_The_Role_of_Laboratory_Experiments_in_the_Validation_of_Field_Data [accessed Jan 15 2018]....

The GSF secondary standard dosimetry laboratory for photon and beta radiation

International Nuclear Information System (INIS)

Eckerl, H.; Nahrstedt, U.

1986-03-01

A brief outline of the laboratory's tasks and a detailed description of its layout and equipment is given. The laboratory contains a Co-60 irradiation unit, a Cs-137 irradiation unit, a panoramic irradiation unit for different nuclide sources, a 160- and 420 kV X-ray unit, a beta-irradiation unit and a measuring and control room. The calibration laboratory is equipped with reference and field dosemeters. (DG)

Radiation chemistry in the Jovian stratosphere - Laboratory simulations

Science.gov (United States)

Mcdonald, Gene D.; Thompson, W. R.; Sagan, Carl

1992-01-01

The results of the present low-pressure/continuous-flow laboratory simulations of H2/He/CH4/NH3 atmospheres' plasma-induced chemistry indicate radiation yields of both hydrocarbon and N2-containing organic compounds which increase with decreasing pressure. On the basis of these findings, upper limits of 1 million-1 billion molecules/sq cm/sec are established for production rates of major auroral-chemistry species in the Jovian stratosphere. It is noted that auroral processes may account for 10-100 percent of the total abundances of most of the observed polar-region organic species.

Optimization of radiation safety conditions in radon laboratories

International Nuclear Information System (INIS)

Kibal'nik, S.P.; Koroleva, T.M.

1990-01-01

The study was aimed at studying working conditions of personnel, engaged in production and supply of radon solution in medical and prophylactic institutions of the Kaliningrad region for the period 1962-1988. Data on examinations carried out at radon laboratories during this period by radiological group of the Kaliningrad sanitary epidemiological station were used as a basis for the study. Positive dynamics of indicators of radiation safety of the persons working at these objects is indicated, concrete measures and ways for improving working conditions of the personnel and role of sanitary epidemiological service in solving these problems are shown. 2 refs.; 1 tab

Real-time dosimetry system in catheterisation laboratory: utility as a learning tool in radiation protection

International Nuclear Information System (INIS)

Pinto Monedero, M.; Rodriguez Cobo, C.; Pifarre Martinez, X.; Ruiz Martin, J.; Barros Candelero, J.M.; Goicolea Ruigomez, J.; Diaz Blaires, G.; Garcia Lunar, I.

2015-01-01

Document available in abstract form only. Full text of publication follows: Workers at the catheter laboratory are among the most exposed to ionising radiation in hospitals. However, it is difficult to be certain of the radiation doses received by the staff, as personal dosemeters are often misused, and thus, the dose history is not reliable. Moreover, the information provided by personal dosemeters corresponds to the monthly accumulated dose, so corrective actions tends to be delayed. The purpose of this work is, on the one hand, to use a real-time dosimetry system to establish the occupational doses per procedure of workers at the catheter laboratories and, on the other hand, to evaluate its utility as a learning tool for radiation protection purposes with the simultaneous video recording of the interventions. (authors)

Absorbing Aerosols: Field and Laboratory Studies of Black Carbon and Dust

Science.gov (United States)

Aiken, A. C.; Flowers, B. A.; Dubey, M. K.

2011-12-01

Currently, absorbing aerosols are thought to be the most uncertain factor in atmospheric climate models (~0.4-1.2 W/m2), and the 2nd most important factor after CO2 in global warming (1.6 W/m2; Ramanathan and Carmichael, Nature Geoscience, 2008; Myhre, Science, 2009). While most well-recognized atmospheric aerosols, e.g., sulfate from power-plants, have a cooling effect on the atmosphere by scattering solar radiation, black carbon (BC or soot) absorbs sunlight strongly which results in a warming of the atmosphere. Dust particles are also present globally and can absorb radiation, contributing to a warmer and drier atmosphere. Direct on-line measurements of BC and hematite, an absorbing dust aerosol, can be made with the Single Particle Soot Photometer (SP2), which measures the mass of the particles by incandescence on an individual particle basis. Measurements from the SP2 are combined with absorption measurements from the three-wavelength photoacoustic soot spectrometer (PASS-3) at 405, 532, and 781 nm and the ultraviolet photoacoustic soot spectrometer (PASS-UV) at 375 nm to determine wavelength-dependent mass absorption coefficients (MACs). Laboratory aerosol samples include flame-generated soot, fullerene soot, Aquadag, hematite, and hematite-containing dusts. Measured BC MAC's compare well with published values, and hematite MAC's are an order of magnitude less than BC. Absorbing aerosols measured in the laboratory are compared with those from ambient aerosols measured during the Las Conchas fire and BEACHON-RoMBAS. The Las Conchas fire was a wildfire in the Jemez Mountains of New Mexico that burned over 100,000 acres during the Summer of 2011, and BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen - Rocky Mountain Biogenic Aerosol Study) is a field campaign focusing on biogenic aerosols at the Manitou Forest Observatory near Colorado Springs, CO in Summer 2011. Optical properties and size

Limited-field radiation for bifocal germinoma

International Nuclear Information System (INIS)

Lafay-Cousin, Lucie; Millar, Barbara-Ann; Mabbott, Donald; Spiegler, Brenda; Drake, Jim; Bartels, Ute; Huang, Annie; Bouffet, Eric

2006-01-01

Purpose: To report the incidence, characteristics, treatment, and outcomes of bifocal germinomas treated with chemotherapy followed by focal radiation. Methods and Materials: This was a retrospective review. Inclusion criteria included radiologic diagnosis of bifocal germinoma involving the pineal and neurohypophyseal region, no evidence of dissemination on spinal MRI, negative results from cerebrospinal fluid cytologic evaluation, and negative tumor markers. Results: Between 1995 and 2004, 6 patients (5 male, 1 female; median age, 12.8 years) fulfilled the inclusion criteria. All had symptoms of diabetes insipidus at presentation. On MRI, 4 patients had a pineal and suprasellar mass, and 2 had a pineal mass associated with abnormal neurohypophyseal enhancement. All patients received chemotherapy followed by limited-field radiation and achieved complete remission after chemotherapy. The radiation field involved the whole ventricular system (range, 2,400-4,000 cGy) with or without a boost to the primary lesions. All patients remain in complete remission at a median follow-up of 48.1 months (range, 9-73.4 months). Conclusions: This experience suggests that bifocal germinoma can be considered a locoregional rather than a metastatic disease. Chemotherapy and focal radiotherapy might be sufficient to provide excellent outcomes. Staging refinement with new diagnostic tools will likely increase the incidence of the entity

The West Africa Field Epidemiology and Laboratory Training ...

African Journals Online (AJOL)

The West Africa Field Epidemiology and Laboratory Training Program, a strategy to improve disease surveillance and epidemic control in West Africa. ... The program includes four countries: Burkina Faso, Mali, Niger, and Togo with an overarching goal to progressively cover all French speaking countries in West Africa ...

Soil erodibility variability in laboratory and field rainfall simulations

Science.gov (United States)

Szabó, Boglárka; Szabó, Judit; Jakab, Gergely; Centeri, Csaba; Szalai, Zoltán

2017-04-01

Rainfall simulation experiments are the most common way to observe and to model the soil erosion processes in in situ and ex situ circumstances. During modelling soil erosion, one of the most important factors are the annual soil loss and the soil erodibility which represent the effect of soil properties on soil loss and the soil resistance against water erosion. The amount of runoff and soil loss can differ in case of the same soil type, while it's characteristics determine the soil erodibility factor. This leads to uncertainties regarding soil erodibility. Soil loss and soil erodibility were examined with the investigation of the same soil under laboratory and field conditions with rainfall simulators. The comparative measurement was carried out in a laboratory on 0,5 m2, and in the field (Shower Power-02) on 6 m2 plot size where the applied slope angles were 5% and 12% with 30 and 90 mm/h rainfall intensity. The main idea was to examine and compare the soil erodibility and its variability coming from the same soil, but different rainfall simulator type. The applied model was the USLE, nomograph and other equations which concern single rainfall events. The given results show differences between the field and laboratory experiments and between the different calculations. Concerning for the whole rainfall events runoff and soil loss, were significantly higher at the laboratory experiments, which affected the soil erodibility values too. The given differences can originate from the plot size. The main research questions are that: How should we handle the soil erodibility factors and its significant variability? What is the best solution for soil erodibility determination?

Determination of the scattered radiation at the Neutron Calibration Laboratory of IPEN using the shadow cone method

Energy Technology Data Exchange (ETDEWEB)

Alvarenga, Tallyson S.; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Freitas, Bruno M. [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Fonseca, Evaldo S.; Pereira, Walsan W., E-mail: talvarenga@ipen.br, E-mail: lcaldas@ipen.br, E-mail: bfreitas@con.ufrj.br, E-mail: walsan@ird.gov.br, E-mail: evaldo@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

Because of the increase in the demand for the calibration of neutron detectors, there is a need for new calibration services. In this context, the Calibration Laboratory of Instituto de Pesquisas Energéticas e Nucleares (IPEN), São Paulo, which already offers calibration services of radiation detectors with standard X, gamma, beta and alpha beams, has recently projected a new test laboratory for neutron detectors. This work evaluated the contribution of dispersed neutron radiation in this laboratory, using the cone shadow method and a Bonner sphere spectrometer to take the measurements at a distance of 100 cm from the neutron source. The dosimetric quantities H⁎(10) and H⁎(10) were obtained at the laboratory, allowing the calibration of detectors. (author)

Determination of the scattered radiation at the Neutron Calibration Laboratory of IPEN using the shadow cone method

International Nuclear Information System (INIS)

Alvarenga, Tallyson S.; Caldas, Linda V.E.; Freitas, Bruno M.

2017-01-01

Because of the increase in the demand for the calibration of neutron detectors, there is a need for new calibration services. In this context, the Calibration Laboratory of Instituto de Pesquisas Energéticas e Nucleares (IPEN), São Paulo, which already offers calibration services of radiation detectors with standard X, gamma, beta and alpha beams, has recently projected a new test laboratory for neutron detectors. This work evaluated the contribution of dispersed neutron radiation in this laboratory, using the cone shadow method and a Bonner sphere spectrometer to take the measurements at a distance of 100 cm from the neutron source. The dosimetric quantities H⁎(10) and H⁎(10) were obtained at the laboratory, allowing the calibration of detectors. (author)

Individual laboratory-measured discount rates predict field behavior.

Science.gov (United States)

Chabris, Christopher F; Laibson, David; Morris, Carrie L; Schuldt, Jonathon P; Taubinsky, Dmitry

2008-12-01

We estimate discount rates of 555 subjects using a laboratory task and find that these individual discount rates predict inter-individual variation in field behaviors (e.g., exercise, BMI, smoking). The correlation between the discount rate and each field behavior is small: none exceeds 0.28 and many are near 0. However, the discount rate has at least as much predictive power as any variable in our dataset (e.g., sex, age, education). The correlation between the discount rate and field behavior rises when field behaviors are aggregated: these correlations range from 0.09-0.38. We present a model that explains why specific intertemporal choice behaviors are only weakly correlated with discount rates, even though discount rates robustly predict aggregates of intertemporal decisions.

Upgrading the Medical Physics Calibration Laboratory Towards ISO/IEC 17025: Radiation Standards and Calibration in Diagnostic Radiology

International Nuclear Information System (INIS)

Asmaliza Hashim; Muhammad Jamal Md Isa; Abd Aziz Mhd Ramli; Wan Hazlinda Ismail; Norhayati Abdullah; Shahrul Azlan Azizan; Siti Sara Deraman; Nor Azlin Azraai; Md Khairusalih Md Zin

2010-01-01

Calibration of quality control (QC) test tools used in diagnostic radiology is legally required under the Ministry of Health (MOH) requirement. The Medical Physics Calibration Laboratory of the Malaysian Nuclear Agency is the national focal point for the calibration of quality control test tools used in diagnostic radiology. The Medical Physics Calibration Laboratory has measurement traceability to primary standard dosimetry laboratory (Physikalisch-Technische Bundesanstalt (PTB)), thus providing an interface between the primary standard dosimetry laboratory and Malaysian hospitals, clinics and license class H holder. The Medical Physics Calibration Laboratory facility is comprised of a constant potential x-ray system with a capability of 160 kV tube and a series of reference and working standard ion chambers. The stability of reference and working standard ion chambers was measured using strontium-90. Dosimetric instruments used in diagnostic radiology is calibrated in terms of air kerma to comply with an International Code of Practices of dosimetry for example IAEA's Technical Report Series number 457. The new series of standard radiation qualities was established based on ISO/IEC 61267. The measurement of beam homogeneity was measured using film and ion chamber to define the field size at certain distance and kV output was measured using the spectrometer and non-invasive kVp meter. The uncertainties measurement was determined with expended uncertainties to a level of confidence of approximately 95% (coverage factor k=2). This paper describes the available facility and the effort of the Medical Physics Calibration Laboratory to upgrade the laboratory towards ISO/IEC 17025. (author)

Characteristic of the radiation field in low earth orbit and in deep space

International Nuclear Information System (INIS)

Reitz, Guenther

2008-01-01

The radiation exposure in space by cosmic radiation can be reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot be completely avoided. The reason for that are the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt comes closer to the earth surface due to a displacement of the magnetic dipole axes from the Earth's center. In addition there is an albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60 latitude in Polar Regions. The radiation field has spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will be crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but subsequently the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. The report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth

Characteristic of the radiation field in low Earth orbit and in deep space.

Science.gov (United States)

Reitz, Guenther

2008-01-01

The radiation exposure in space by cosmic radiation can be reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot be completely avoided. The reason for that are the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt comes closer to the earth surface due to a displacement of the magnetic dipole axes from the Earth's center. In addition there is an albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60" latitude in Polar Regions. The radiation field has spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will be crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but subsequently the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. The report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth

Biological reduction of uranium-From the laboratory to the field

International Nuclear Information System (INIS)

Dullies, Frank; Lutze, Werner; Gong, Weiliang; Nuttall, H. Eric

2010-01-01

The chemical and biological processes underlying in situ bioremediation of uranium-contaminated groundwater have been studied in the laboratory and in the field. This article focuses on the long-term stability of uraninite (UO 2 ) in the underground. A large tailings pond, 'Daenkritz 1' in Germany, was selected for this investigation. A single-pass flow-through experiment was run in a 100-liter column: bioremediation for 1 year followed by infiltration of tap water (2.5 years) saturated with oxygen, sufficient to oxidize the precipitated uraninite in two months. Instead, only 1 wt.% uraninite was released over 2.4 years at concentrations typically less than 20 μg/L. Uraninite was protected against oxidation by the mineral mackinawite (FeS 0.9 ), a considerable amount of which had formed, together with uraninite. A confined field test was conducted adjacent to the tailings pond, which after bio-stimulation showed similarly encouraging results as in the laboratory. Taking Daenkritz 1 as an example we show that in situ bioremediation can be a viable option for long-term site remediation, if the process is designed based on sufficient laboratory and field data. The boundary conditions for the site in Germany are discussed.

Correlation between Auroral kilometric radiation and field-aligned currents

International Nuclear Information System (INIS)

Green, J.L.; Saflekos, N.A.; Gurnett, D.A.; Potemra, T.A.

1982-01-01

Simultaneous observations of field-aligned currents (FAC) and auroral kilometric radiation (AKR) are compared from the polar-orbiting satellites Triad and Hawkeye. The Triad observations were restricted to the evening-to-midnight local time sector (1900 to 0100 hours magnetic local time) in the northern hemisphere. This is the region in which the most intense storms of AKR are believed to originate. The Hawkeye observations were restricted to when the satellite was in the AKR emission cone in the northern hemisphere and at radial distances > or =7R/sub E/ (earth radii) to avoid local propagation cutoff effects. A(R/7R/sub E/) 2 normalization to the power flux measurements of the kilometric radiation from Hawkeye is used to take into account the radial dependence of this radiation and to scale all intensity measurements so that they are independent of Hawkeye's position in the emission cone. Integrated field-aligned current intensities from Triad are determined from the observed transverse magnetic field disturbances. There appears to be a weak correlation between AKR intensity and the integrated current sheet intensity of field-aligned currents. In general, as the intensity of auroral kilometric radiation increases so does the integrated auroral zone current sheet intensity increase. Statistically, the linear correlation coefficient between the log of the AKR power flux and the log of the current sheet intensity is 0.57. During weak AKR bursts ( - 18 W m - 2 Hz - 1 ), Triad always observed weak FAC'S ( - 1 ), and when Triad observed large FAC's (> or =0.6 A m - 1 ), the AKR intensity from Hawkeye was moderately intense (10 - 5 to 10 - 14 W m - 2 Hz - 1 ) to intense (>10 - 14 W m - 2 Hz - 1 ). It is not clear from these preliminary results what the exact role is that auroral zone field-aligned currents play in the generation or amplification of auroral kilometric radiation

Sound power radiated by sources in diffuse fields

DEFF Research Database (Denmark)

Polack, Jean-Dominique

2000-01-01

Sound power radiated by sources at low frequency notoriously depends on source position. We sampled the sound field of a rectangular room at 18 microphone and 4 source positions. Average power spectra were extrapolated from the reverberant field, taking into account the frequency dependent...

Electromagnetic radiation damping of charges in external gravitational fields (weak field, slow motion approximation). [Harmonic coordinates, weak field slow-motion approximation, Green function

Energy Technology Data Exchange (ETDEWEB)

Rudolph, E [Max-Planck-Institut fuer Physik und Astrophysik, Muenchen (F.R. Germany)

1975-01-01

As a model for gravitational radiation damping of a planet the electromagnetic radiation damping of an extended charged body moving in an external gravitational field is calculated in harmonic coordinates using a weak field, slowing-motion approximation. Special attention is paid to the case where this gravitational field is a weak Schwarzschild field. Using Green's function methods for this purpose it is shown that in a slow-motion approximation there is a strange connection between the tail part and the sharp part: radiation reaction terms of the tail part can cancel corresponding terms of the sharp part. Due to this cancelling mechanism the lowest order electromagnetic radiation damping force in an external gravitational field in harmonic coordinates remains the flat space Abraham Lorentz force. It is demonstrated in this simplified model that a naive slow-motion approximation may easily lead to divergent higher order terms. It is shown that this difficulty does not arise up to the considered order.

Report on radiation protection calibration activities in Australia

International Nuclear Information System (INIS)

Hargrave, N.J.

1995-01-01

Australia is a federation of eight autonomous States or Territories. Each of these is responsible for many matters including radiation safety within their borders. National matters are the responsibility of the Federal Government. The Australian Radiation Laboratory (ARL) is a part of the Federal Government Department of Human Services and Health and undertakes research and service activities related to radiation health. Work related to both ionising and non ionising radiation and regulatory matters is performed. Some of the research activities relate to radiation measurement standards, environmental radioactivity (e.g. radon in air, radioactivity in drinking water), effects of electro-magnetic fields on health (ELF), ultra violet radiation (UV) and laser safety, radiochemistry, medical applications of radiation (and doses to the population as a result), general health physics, thermoluminescent dosimetry (TLD) and electron spin resonance (ESR) dosimetry. The calibration of protection instruments are undertaken by the Ionising Radiation Standards Group within the Laboratory and by State Health Laboratories. (J.P.N.)

Radiation protection in clinical chemical laboratories

International Nuclear Information System (INIS)

Jacob, K.

1980-01-01

In the clinical-chemical laboratory, the problems of the personal radiation protection can be handled relatively simply. Important conditions are certain requirements as far as the building is concerned and the keeping to protection measures to invoid ingestion, inhalation, and resorption of open radioactive substances. Very intensive attention must be paid to a clean working technique in order to be able to exclude the danger of contamination which is very disturbing during the extremely sensitive measurements. The higgest problem in the handling of open radioactive substances, however, is in our opinion the waste management because it requires which space and personnel this causing high costs. Furthermore, since 1 January 1979, the permission for the final storage of radioactive waste in the shut down mine ASSE was taken back from the county collection places and it cannot be said yet if and when this permission will be given again. (orig./HP) [de

University Physics Students' Ideas of Thermal Radiation Expressed in Open Laboratory Activities Using Infrared Cameras

Science.gov (United States)

Haglund, Jesper; Melander, Emil; Weiszflog, Matthias; Andersson, Staffan

2017-01-01

Background: University physics students were engaged in open-ended thermodynamics laboratory activities with a focus on understanding a chosen phenomenon or the principle of laboratory apparatus, such as thermal radiation and a heat pump. Students had access to handheld infrared (IR) cameras for their investigations. Purpose: The purpose of the…

Vibration analysis and sound field characteristics of a tubular ultrasonic radiator.

Science.gov (United States)

Liang, Zhaofeng; Zhou, Guangping; Zhang, Yihui; Li, Zhengzhong; Lin, Shuyu

2006-12-01

A sort of tubular ultrasonic radiator used in ultrasonic liquid processing is studied. The frequency equation of the tubular radiator is derived, and its radiated sound field in cylindrical reactor is calculated using finite element method and recorded by means of aluminum foil erosion. The results indicate that sound field of tubular ultrasonic radiator in cylindrical reactor appears standing waves along both its radial direction and axial direction, and amplitudes of standing waves decrease gradually along its radial direction, and the numbers of standing waves along its axial direction are equal to the axial wave numbers of tubular radiator. The experimental results are in good agreement with calculated results.

Intensity of low-frequency radiations and the interplanetary magnetic field

International Nuclear Information System (INIS)

Larkina, V.I.; Likhter, Ya.I.

1983-01-01

The data of measurements of ELF/VLF radiations at ''Interkosmos-13'' artificial Earth satellite in auroral latitudes and in the polar cap in the vernal equinox of 1975 are compared with characteristics of interplanetary magnetic field (IMF). The absence of north-south asymmetry of variations of ELF/VLF-radiation Intensity in the outer ionosphere versus the IMF characteristics is noted. The intensity of natural ELF- and VLF-radiations depends in a complex way on parameters of the magnetospheric plasma: composition and concentration of ''cold'' particles, geomagnetic field intensity, properties of energetic particle fluxes. The considered variations in the radiation amplitude versus the IMF characteristics show the predominant role of the sector structure polarity and IMF Bsub(y) component sign

Thyorid function after mantle field radiation therapy

International Nuclear Information System (INIS)

Daehnert, W.; Kutzner, J.; Grimm, W.

1981-01-01

48 patients with malignant lymphoma received a 60 Co-radiation dose of 30 to 50 Gy using the mantle field technique. Thyroid function tests were performed 34 to 92 months after radiation therapy. One patient developed myxedema, ten (20.8%) had subclinical hypothyroidism and six (12.5%) latent hypothyroidism. The incidence of hypothyroidism after treatment of malignant lymphomas is summarized in a review of the literature. Discrepancies on the incidence of hypothyroidism were found, and their possible cause is discussed. Periodic examinations of all patients with thyroid radiation exposure are recommended. The examination can be limited to measurement of TSH concentration and palpation of the thyroid for nodules. (orig.) [de

[Strategy Development for International Cooperation in the Clinical Laboratory Field].

Science.gov (United States)

Kudo, Yoshiko; Osawa, Susumu

2015-10-01

The strategy of international cooperation in the clinical laboratory field was analyzed to improve the quality of intervention by reviewing documents from international organizations and the Japanese government. Based on the world development agenda, the target of action for health has shifted from communicable diseases to non-communicable diseases (NCD). This emphasizes the importance of comprehensive clinical laboratories instead of disease-specific examinations in developing countries. To achieve this goal, the World Health Organization (WHO) has disseminated to the African and Asian regions the Laboratory Quality Management System (LQMS), which is based on the same principles of the International Organization of Standardization (ISO) 15189. To execute this strategy, international experts must have competence in project management, analyze information regarding the target country, and develop a strategy for management of the LQMS with an understanding of the technical aspects of laboratory work. However, there is no appropriate pre- and post-educational system of international health for Japanese international workers. Universities and academic organizations should cooperate with the government to establish a system of education for international workers. Objectives of this education system must include: (1) training for the organization and understanding of global health issues, (2) education of the principles regarding comprehensive management of clinical laboratories, and (3) understanding the LQMS which was employed based on WHO's initiative. Achievement of these objectives will help improve the quality of international cooperation in the clinical laboratory field.

Facility - Radiation Source Features and User Applications

International Nuclear Information System (INIS)

Gover, A.; Abramovich, A.; Eichenbaum, A.L.; Kanter, M.; Sokolowski, J.; Yahalom, A.; Shiloh, J.; Schnitzer, I.; Pinhasi, Y.

1999-01-01

Recent measurements of the radiation characteristics of the tandem FEL prove .that the device operates as a high quality, tunable radiation source in the mm wave regime. Tuning range of 60% around a central frequency of 100 GHz was demonstrated by varying the tandem accelerator energy from 1 to 1.5 MeV with 1-1.5 Amp. Beam current. Fourier transform limited linewidth of Δ f/f -5 was measured in single-mode lasing operation. The FEL power in pulse operation (10μsec) was 10 kWatt. Operating the FEL at high repetition rate with 0.1 to 1 mSec pulses will make it possible to obtain high average power (1 kWatt) and narrow linewidth (10 -7 ). Based ,on these exceptional properties of the FEL as a high quality spectroscopic tool and as a source of high average power radiation, the FEL consortium, supported by a body of 10 radiation user groups from various universities and research institutes, embark on a new project for development of an Israeli FEL radiation user laboratory. The laboratory is presently in a design and building stage in the academic campus in Ariel. The FEL will be moved to this laboratory after completion of X-ray protection structure in the allocated building. In the first phase of development, the radiation user laboratory will consist of three user stations: a. Spectroscopic station (low average power). Material studies are planned in the fields of H.T.S.C., submicron semiconductor devices, gases. b. Material processing station (high average power). Experiments are planned in the fields of thin film ceramic sintering (including H.T.S.C.), functionally graded materials, surface treatment of metals, interaction with biological tissues. c. Atmospheric study station. Experiments are planned in the fields of aerosol, dust and clouds mapping, remote sensing of gases, wide-band mm wave communication The FEL experimental results and the user laboratory features will be described

Evaluate existing radiation fields

International Nuclear Information System (INIS)

Aldrich, J.M.; Haggard, D.L.; Endres, G.W.R.; Fix, J.J.

1981-01-01

Knowledge of the spectrum of energies for beta, gamma, and neutron radiation experienced in the field is crucial to the proper interpretation of personnel dose. Calibration sources and techniques are determined on the basis of their relationship to field exposure. Selected techniques were used to obtain neutron, photon, and beta energy spectra data at several Hanford locations. Four neutron energy spectra and dose measurement methods were used: (1) multisphere spectrometer system; (2) tissue equivalent proportional counter (TEPC); (3) RASCAL (9'' to 3'' sphere ratios); and (4) helium-3 neutron spectrometer. Gamma spectroscopy was done using standard techniques. A specially designed TLD dosimeter was used to obtain beta spectrum measurements. The design and use of each of these instruments is described in the body of this report. Data collected and analyzed for each of the Hanford locations are included

DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009–2016

Directory of Open Access Journals (Sweden)

Berger Thomas

2017-01-01

Full Text Available The natural radiation environment in Low Earth Orbit (LEO differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR, as well as of protons and electrons trapped in the Earth’s radiation belts (Van Allen belts. Protons and some heavier particles ejected in occasional Solar Particle Events (SPEs might in addition contribute to the radiation exposure in LEO. All sources of radiation are modulated by the solar cycle. During solar maximum conditions SPEs occur more frequently with higher particle intensities. Since the radiation exposure in LEO exceeds exposure limits for radiation workers on Earth, the radiation exposure in space has been recognized as a main health concern for humans in space missions from the beginning of the space age on. Monitoring of the radiation environment is therefore an inevitable task in human spaceflight. Since mission profiles are always different and each spacecraft provides different shielding distributions, modifying the radiation environment measurements needs to be done for each mission. The experiments “Dose Distribution within the ISS (DOSIS” (2009–2011 and “Dose Distribution within the ISS 3D (DOSIS 3D” (2012–onwards onboard the Columbus Laboratory of the International Space Station (ISS use a detector suite consisting of two silicon detector telescopes (DOSimetry TELescope = DOSTEL and passive radiation detector packages (PDP and are designed for the determination of the temporal and spatial variation of the radiation environment. With the DOSTEL instruments’ changes of the radiation composition and the related exposure levels in dependence of the solar cycle, the altitude of the ISS and the influence of attitude changes of the ISS during Space Shuttle dockings inside the Columbus Laboratory have been monitored. The absorbed doses measured at the end of May 2016

Radiation from channeled positrons in a hypersonic wave field

International Nuclear Information System (INIS)

Mkrtchyan, A.R.; Gasparyan, R.A.; Gabrielyan, R.G.

1987-01-01

The radiation emitted by channeled positrons in a longitudinal or transverse standing hypersonic wave field is considered. In the case of plane channeling the spectral distribution of the radiation intensity is shown to be of a resonance nature depending on the hypersound frequency

Radiation drag in the field of a non-spherical source

Science.gov (United States)

Bini, D.; Geralico, A.; Passamonti, A.

2015-01-01

The motion of a test particle in the gravitational field of a non-spherical source endowed with both mass and mass quadrupole moment is investigated when a test radiation field is also present. The background is described by the Erez-Rosen solution, which is a static space-time belonging to the Weyl class of solutions to the vacuum Einstein's field equations, and reduces to the familiar Schwarzschild solution when the quadrupole parameter vanishes. The radiation flux has a fixed but arbitrary (non-zero) angular momentum. The interaction with the radiation field is assumed to be Thomson-like, i.e. the particles absorb and re-emit radiation, thus suffering for a friction-like drag force. Such an additional force is responsible for the Poynting-Robertson effect, which is well established in the framework of Newtonian gravity and has been recently extended to the general theory of relativity. The balance between gravitational attraction, centrifugal force and radiation drag leads to the occurrence of equilibrium circular orbits which are attractors for the surrounding matter for every fixed value of the interaction strength. The presence of the quadrupolar structure of the source introduces a further degree of freedom: there exists a whole family of equilibrium orbits parametrized by the quadrupole parameter, generalizing previous works. This scenario is expected to play a role in the context of accretion matter around compact objects.

Electromagnetic radiation of protons in edge fields of synchrotron dipole magnets

International Nuclear Information System (INIS)

Smolyakov, N.V.

1986-01-01

Effect of the edge shape of magnetic field of a dipole on the short-wave part of electromagnetic radiation spectrum of a proton beam is investigated. In some cases short-wave photons are shown to be shaped in the ranges of largest edge curvature of the magnetic field. Universality of edge radiation spectrum is proved. Spectral characteristics of proton edge radiation in a superconducting magnetic dipole of the storage-accelerator complex are obtained

Development of Object Simulator for Radiation Field of Dental X-Rays

International Nuclear Information System (INIS)

Silva, L F; Ferreira, F C L; Sousa, F F; Cardoso, L X; Vasconcelos, E D S; Brasil, L M

2013-01-01

In dentistry radiography is of fundamental importance to the dentist can make an accurate diagnosis. For this it is necessary to pay attention to the radiological protection of both the professional and the patient and control image quality for an accurate diagnosis. In this work, quality control tests were performed on X-ray machines in private dental intraoral in the municipality of Marabá, where they measured the diameters of the radiation field to see if these machines are in accordance with the recommendations, thus preventing the patient is exposed to a radiation field higher than necessary. We will study the results of each X-ray machine evaluated. For this we created a phantom to assess the size of the radiation field of X-ray dental, where we measure the radiation field of each device to see if they are in accordance with the recommendations of the ordinance No. 453/98 – MS

Laboratory and field evaluation of broiler litter nitrogen mineralization.

Science.gov (United States)

Sistani, K R; Adeli, A; McGowen, S L; Tewolde, H; Brink, G E

2008-05-01

Two studies were conducted for this research. First, a laboratory incubation to quantify broiler litter N mineralization with the following treatments: two soil moisture regimes, constant at 60% water fill pore space (WFPS) and fluctuating (60-30% WFPS), three soil types, Brooksville silty clay loam, Ruston sandy loam from Mississippi, and Catlin silt loam from Illinois. Second, a field incubation study to quantify broiler litter N mineralization using similar soils and litter application rates as the laboratory incubation. Broiler litter was applied at an equivalent rate of 350 kg total N ha(-1) for both studies except for control treatments. Subsamples were taken at different timing for both experiments for NO3-N and NH4-N determinations. In the laboratory experiment, soil moisture regimes had no significant impact on litter-derived inorganic N. Total litter-derived inorganic N across all treatments increased from 23 mg kg(-1) at time 0, to 159 mg kg(-1) at 93 d after litter application. Significant differences were observed among the soil types. Net litter-derived inorganic N was greater for Brooksville followed by Ruston and Catlin soils. For both studies and all soils, NH4-N content decreased while NO3-N content increased indicating a rapid nitrification of the mineralized litter N. Litter mineralization in the field study followed the same trend as the laboratory study but resulted in much lower net inorganic N, presumably due to environmental conditions such as precipitation and temperature, which may have resulted in more denitrification and immobilization of mineralized litter N. Litter-derived inorganic N from the field study was greater for Ruston than Brooksville. Due to no impact by soil moisture regimes, additional studies are warranted in order to develop predictive relationships to quantify broiler litter N availability.

Field and laboratory evaluations of soybean lines against soybean aphid (Hemiptera: Aphididae).

Science.gov (United States)

Hesler, Louis S; Prischmann, Deirdre A; Dashiell, Kenton E

2012-04-01

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major pest of soybean, Glycine max (L.). Merr., that significantly reduces yield in northern production areas of North America. Insecticides are widely used to control soybean aphid outbreaks, but efforts are underway to develop host plant resistance as an effective alternative management strategy. Here, previously identified resistant lines were evaluated in laboratory tests against field-collected populations of soybean aphid and in field-plot tests over 2 yr in South Dakota. Six lines previously identified with resistance to soybean aphid--Jackson, Dowling, K1639, Cobb, Palmetto and Sennari--were resistant in this study, but relatively high aphid counts on Tie-feng 8 in field plots contrasted with its previously reported resistance. Bhart-PI 165989 showed resistance in one of two laboratory tests, but it had relatively large aphid infestations in both years of field tests. Intermediate levels of soybean aphid occurred in field plots on lines previously shown to have strong (Sugao Zairai, PI 230977, and D75-10169) or moderate resistance to soybean aphid (G93-9223, Bragg, Braxton, and Tracy-M). Sugao Zairai also failed to have a significant proportion of resistant plants in two laboratory tests against aphids field-collected in 2008, but it was resistant in laboratory tests with aphids collected in 2002, 2005, and 2006. Overall, results showed that lines with Rag (i.e., Jackson) or Rag1 gene (i.e., Dowling) had low aphid numbers, whereas lines with Rag2 (i.e., Sugao Zairai, Sennari) had mixed results. Collectively, responses of soybean aphid populations in laboratory and field tests in 2008 resembled a virulence pattern reported previously for biotype 3 soybean aphids, but virulence in soybean aphid populations was variable and dynamic over years of the study. These results, coupled with previous reports of biotypes virulent to Rag1, suggest that deployment of lines with a single aphid

Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory.

Science.gov (United States)

Zeitlin, C; Hassler, D M; Cucinotta, F A; Ehresmann, B; Wimmer-Schweingruber, R F; Brinza, D E; Kang, S; Weigle, G; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Köhler, J; Martin, C; Posner, A; Rafkin, S; Reitz, G

2013-05-31

The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert.

Technical qualification requirements and training programs for radiation protection personnel at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Copenhaver, E.D.; Houser, B.S.; Butler, H.M. Jr.; Bogard, J.S.; Fair, M.F.; Haynes, C.E.; Parzyck, D.C.

1986-04-01

This document deals with the policies and practices of the Environmental and Occupational Safety Division (EOSD) at the Oak Ridge National Laboratory (ORNL) in regard to the selection, training, qualification, and requalification of radiation protection staff assigned to reactor and nonreactor nuclear facilities. Included are personnel at facilities that: (1) operate reactors or particle accelerators; (2) produce, process, or store radioactive liquid or solid waste; (3) conduct separations operations; (4) engage in research with radioactive materials and radiation sources; and (5) conduct irradiated materials inspection, fuel fabrication, deconamination, or recovery operations. The EOSD personnel also have environmental surveillance and operational and industrial safety responsibilities related to the total Laboratory

Recent developments in radiation field control technology

International Nuclear Information System (INIS)

Wood, C.J.

1995-01-01

The U.S. nuclear power industry has been remarkably successful in reducing worker radiation exposures over the past ten years. There has been over a fourfold reduction in the person-rem incurred for each MW.year of electric power generated: from 1.8 in 1980, to only 0.39 person-rems in 1991 and 1992. Preliminary data for 1993 are even lower: approximately 0.37 person-rem.MW.year. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in ICRP 60 and there will be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts with be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the industry goals for 1995. Reducing out-of-core radiation fields offer the best chance of continuing the downward trend in exposures. To assist utilities select the most economic technology for their specific plants, EPRI has published a manual capturing worldwide operating experience with radiation-field control techniques (TR-100265). No one method will suffice, but implementing suitable combinations from this collection will enable utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: outages are shorter, manpower requirements are reduced and work quality is improved. Despite the up front costs, the benefits over the following 1-3 years typically outweigh the expenses

Recent developments in radiation field control technology

Energy Technology Data Exchange (ETDEWEB)

Wood, C.J. [Electric Power Research Institute, Palo Alto, CA (United States)

1995-03-01

The U.S. nuclear power industry has been remarkably successful in reducing worker radiation exposures over the past ten years. There has been over a fourfold reduction in the person-rem incurred for each MW.year of electric power generated: from 1.8 in 1980, to only 0.39 person-rems in 1991 and 1992. Preliminary data for 1993 are even lower: approximately 0.37 person-rem.MW.year. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in ICRP 60 and there will be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts with be increased requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the industry goals for 1995. Reducing out-of-core radiation fields offer the best chance of continuing the downward trend in exposures. To assist utilities select the most economic technology for their specific plants, EPRI has published a manual capturing worldwide operating experience with radiation-field control techniques (TR-100265). No one method will suffice, but implementing suitable combinations from this collection will enable utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: outages are shorter, manpower requirements are reduced and work quality is improved. Despite the up front costs, the benefits over the following 1-3 years typically outweigh the expenses.

Six categories of ionizing radiation quantities practical in various fields

International Nuclear Information System (INIS)

Zheng Junzheng; Zhuo Weihai

2011-01-01

This paper is the part of review on the evolvement of the systems for ionizing radiation quantities and units. In the paper, for better understanding and correct use of the relevant quantities of ionizing radiation, the major ionizing radiation quantities in various fields are divided into six categories. (authors)

Lightweight space radiator with leakage control by internal electrostatic fields

International Nuclear Information System (INIS)

Kim, H.; Bankoff, S.G.; Miksis, M.J.

1991-01-01

An electrostatic liquid film space radiator is proposed. This will employ an internal electrostatic field to prevent leakage of the liquid-metal coolant out of a puncture. This overcomes the major disadvantage of membrane radiators, which is their vulnerability to micrometeorite impacts. Calculations show that leaks of liquid lithium at 700 degree K can easily be stopped from punctures which are several mm in diameter, with very large safety factors. The basic idea lends itself to a variety of radiator concepts, both rotating and non-rotating. Some typical film thickness and pressure calculations in the presence of an electric field are shown

Graphene-assisted near-field radiative heat transfer between corrugated polar materials

International Nuclear Information System (INIS)

Liu, X. L.; Zhang, Z. M.

2014-01-01

Graphene has attracted great attention in nanoelectronics, optics, and energy harvesting. Here, the near-field radiative heat transfer between graphene-covered corrugated silica is investigated based on the exact scattering theory. It is found that graphene can improve the radiative heat flux between silica gratings by more than one order of magnitude and alleviate the performance sensitivity to lateral shift. The underlying mechanism is mainly attributed to the improved photon tunneling of modes away from phonon resonances. Besides, coating with graphene leads to nonlocal radiative transfer that breaks Derjaguin's proximity approximation and enables corrugated silica to outperform bulk silica in near-field radiation.

Attenuation of VHE Gamma Rays by the Milky Way Interstellar Radiation Field

Energy Technology Data Exchange (ETDEWEB)

Moskalenko, Igor V.; /Stanford U., HEPL; Porter, Troy A.; /Louisiana State U.; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

2006-04-19

The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with multi-wavelength observations by DIRBE and FIRAS indicates that the energy density of the Galactic interstellar radiation field is higher, particularly in the Galactic center, than previously thought. We have made a calculation of the attenuation of very high energy gamma rays in the Galaxy using this new interstellar radiation field which takes into account its nonuniform spatial and angular distributions. We find that the maximum attenuation occurs around 100 TeV at the level of about 25% for sources located at the Galactic center, and is important for both Galactic and extragalactic sources.

Effects of external radiation fields on line emission—application to star-forming regions

Energy Technology Data Exchange (ETDEWEB)

Chatzikos, Marios; Ferland, G. J. [University of Kentucky, Lexington, KY 40506 (United States); Williams, R. J. R. [AWE plc, Aldermaston, Reading RG7 4PR (United Kingdom); Porter, Ryan [Department of Physics and Astronomy and Center for Simulational Physics, University of Georgia, Athens, GA 30602-2451 (United States); Van Hoof, P. A. M., E-mail: mchatzikos@gmail.com [Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Uccle (Belgium)

2013-12-20

A variety of astronomical environments contain clouds irradiated by a combination of isotropic and beamed radiation fields. For example, molecular clouds may be irradiated by the isotropic cosmic microwave background, as well as by a nearby active galactic nucleus. These radiation fields excite atoms and molecules and produce emission in different ways. We revisit the escape probability theorem and derive a novel expression that accounts for the presence of external radiation fields. We show that when the field is isotropic the escape probability is reduced relative to that in the absence of external radiation. This is in agreement with previous results obtained under ad hoc assumptions or with the two-level system, but can be applied to complex many-level models of atoms or molecules. This treatment is in the development version of the spectral synthesis code CLOUDY. We examine the spectrum of a Spitzer cloud embedded in the local interstellar radiation field and show that about 60% of its emission lines are sensitive to background subtraction. We argue that this geometric approach could provide an additional tool toward understanding the complex radiation fields of starburst galaxies.

Microrelief-Controlled Overland Flow Generation: Laboratory and Field Experiments

Directory of Open Access Journals (Sweden)

Xuefeng Chu

2015-01-01

Full Text Available Surface microrelief affects overland flow generation and the related hydrologic processes. However, such influences vary depending on other factors such as rainfall characteristics, soil properties, and initial soil moisture conditions. Thus, in-depth research is needed to better understand and evaluate the combined effects of these factors on overland flow dynamics. The objective of this experimental study was to examine how surface microrelief, in conjunction with the factors of rainfall, soil, and initial moisture conditions, impacts overland flow generation and runoff processes in both laboratory and field settings. A series of overland flow experiments were conducted for rough and smooth surfaces that represented distinct microtopographic characteristics and the experimental data were analyzed and compared. Across different soil types and initial moisture conditions, both laboratory and field experiments demonstrated that a rough soil surface experienced a delayed initiation of runoff and featured a stepwise threshold flow pattern due to the microrelief-controlled puddle filling-spilling-merging dynamics. It was found from the field experiments that a smooth plot surface was more responsive to rainfall variations especially during an initial rainfall event. However, enhanced capability of overland flow generation and faster puddle connectivity of a rough field plot occurred during the subsequent rain events.

Science outside the laboratory measurement in field science and economics

CERN Document Server

Boumans, Marcel

2015-01-01

The conduct of most of social science occurs outside the laboratory. Such studies in field science explore phenomena that cannot for practical, technical, or ethical reasons be explored under controlled conditions. These phenomena cannot be fully isolated from their environment or investigated by manipulation or intervention. Yet measurement, including rigorous or clinical measurement, does provide analysts with a sound basis for discerning what occurs under field conditions, and why. In Science Outside the Laboratory, Marcel Boumans explores the state of measurement theory, its reliability, and the role expert judgment plays in field investigations from the perspective of the philosophy of science. Its discussion of the problems of passive observation, the calculus of observation, the two-model problem, and model-based consensus uses illustrations drawn primarily from economics. Rich in research and discussion, the volume clarifies the extent to which measurement provides valid information about objects an...

Mapping the radiation fields at a research reactor

International Nuclear Information System (INIS)

Soegaard-Hansen, Jens; Warming, Lisbeth

1999-01-01

The DR 3 reactor at Risoe National Laboratory is a multipurpose research reactor. It has the status of a Large European Beam facility therefor its neutron scattering spectrometers are used by many visiting scientists. As a supplement to the routine health physics monitoring programmes a special survey has been made to get more detailed information of the radiation levels in the hall and of the most important sources of the radiation. The special survey consisted of three sorts of measurements: an extra set of thermoluminescence dosimeters, a set of continuous measurements of the dose rate at selected places and spot measurements with handheld instruments around the spectrometers. Some of the results from the survey are presented. (au)

Determination of Soil Moisture Content using Laboratory Experimental and Field Electrical Resistivity Values

Science.gov (United States)

Hazreek, Z. A. M.; Rosli, S.; Fauziah, A.; Wijeyesekera, D. C.; Ashraf, M. I. M.; Faizal, T. B. M.; Kamarudin, A. F.; Rais, Y.; Dan, M. F. Md; Azhar, A. T. S.; Hafiz, Z. M.

2018-04-01

The efficiency of civil engineering structure require comprehensive geotechnical data obtained from site investigation. In the past, conventional site investigation was heavily related to drilling techniques thus suffer from several limitations such as time consuming, expensive and limited data collection. Consequently, this study presents determination of soil moisture content using laboratory experimental and field electrical resistivity values (ERV). Field and laboratory electrical resistivity (ER) test were performed using ABEM SAS4000 and Nilsson400 soil resistance meter. Soil sample used for resistivity test was tested for characterization test specifically on particle size distribution and moisture content test according to BS1377 (1990). Field ER data was processed using RES2DINV software while laboratory ER data was analyzed using SPSS and Excel software. Correlation of ERV and moisture content shows some medium relationship due to its r = 0.506. Moreover, coefficient of determination, R2 analyzed has demonstrate that the statistical correlation obtain was very good due to its R2 value of 0.9382. In order to determine soil moisture content based on statistical correlation (w = 110.68ρ-0.347), correction factor, C was established through laboratory and field ERV given as 19.27. Finally, this study has shown that soil basic geotechnical properties with particular reference to water content was applicably determined using integration of laboratory and field ERV data analysis thus able to compliment conventional approach due to its economic, fast and wider data coverage.

GLOBAL ELECTROMAGNETIC RADIATION POLLUTION: RISK ASSESSMENT FROM FIELD MEASUREMENTS AND ANIMAL EXPERIMENTS

Science.gov (United States)

Fragkopoulou, A. F.; Margaritis, L. H.

2009-12-01

The extended use of wireless technology throughout the globe in almost all developed and non-developed countries has forced a large number of scientists to get involved in the investigation of the effects. The major issue is that unlike other forms of radiation exposure, this “non-ionizing electromagnetic radiation” was not present throughout the evolution of life in earth and therefore there are no adaptive mechanisms evolved. All organisms are vulnerable to the possible effects of radiation depending on the actual exposure level. “Safety limits” on the power density have been proposed but ongoing research has shown that these limits are not really safe for humans, not mentioning the entire population of living creatures on earth. The so called “Electrosmog Pollution” originating from the numerous radio and TV stations, communication satellite emission, but most importantly from mobile phone mast antennas, are of major concern, because it is gradually increasing at exponential rate. Therefore the key question is, do living organisms react upon their exposure to fields of non ionizing electromagnetic radiation? To have this question answered extensive research is being performed in various laboratories. One approach of our research includes field measurements within houses and classrooms, since a considerable proportion of the population in each country is exposed to the radiation coming from the nearby mast stations, in order to make a risk assessment. The measurements showed that in many cases the actual radiation present was potentially harmful. In other words, although the measured values were below the national safety levels, nevertheless they were above the levels of other countries. Therefore it has been suggested that a new cellular network should be constructed in order to minimize radiation levels in living areas and schools. Our experimental work is focusing on the elucidation of the effects of non-ionizing EMFs on mice exposed to mobile

Magnetic fields driven by tidal mixing in radiative stars

Science.gov (United States)

Vidal, Jérémie; Cébron, David; Schaeffer, Nathanaël; Hollerbach, Rainer

2018-04-01

Stellar magnetism plays an important role in stellar evolution theory. Approximatively 10 per cent of observed main sequence (MS) and pre-main-sequence (PMS) radiative stars exhibit surface magnetic fields above the detection limit, raising the question of their origin. These stars host outer radiative envelopes, which are stably stratified. Therefore, they are assumed to be motionless in standard models of stellar structure and evolution. We focus on rapidly rotating, radiative stars which may be prone to the tidal instability, due to an orbital companion. Using direct numerical simulations in a sphere, we study the interplay between a stable stratification and the tidal instability, and assess its dynamo capability. We show that the tidal instability is triggered regardless of the strength of the stratification (Brunt-Väisälä frequency). Furthermore, the tidal instability can lead to both mixing and self-induced magnetic fields in stably stratified layers (provided that the Brunt-Väisälä frequency does not exceed the stellar spin rate in the simulations too much). The application to stars suggests that the resulting magnetic fields could be observable at the stellar surfaces. Indeed, we expect magnetic field strengths up to several Gauss. Consequently, tidally driven dynamos should be considered as a (complementary) dynamo mechanism, possibly operating in radiative MS and PMS stars hosting orbital companions. In particular, tidally driven dynamos may explain the observed magnetism of tidally deformed and rapidly rotating Vega-like stars.

Cost comparison of laboratory methods and four field screening technologies for uranium-contaminated soil

International Nuclear Information System (INIS)

Douthat, D.M.; Armstrong, A.Q.

1994-01-01

To address the problem of characterizing uranium-contaminated surface soil at federal facilities, the Department of Energy has the development of four uranium field screening technologies, under the direction of the Uranium-in-Soils Integrated Demonstration (USID) Program. These four technologies include: a long-range alpha detector a beta scintillation detector, an in situ gamma detector, and a mobile laser ablation-inductively coupled plasma/atomic emission spectrometry (LA-ICP/AES) laboratory. As part of the performance assessment for these field screening technologies, cost estimates for the development and operation of each technology were created. A cost study was conducted to compare three of the USID field screening technologies to the use of traditional field surveying equipment to adequately characterize surface soils of a one-acre site. The results indicate that the use of traditional equipment costs more than the in situ gamma detector, but less than the beta scintillation detector and LRAD. The use of traditional field surveying equipment results in cost savings of 4% and 34% over the use of the beta scintillation and LRAD technologies, respectively. A study of single-point surface soil sampling and laboratory analysis costs was also conducted. Operational costs of the mobile LA-ICP/AES laboratory were compared with operational costs of traditional sampling and analysis, which consists of collecting soil samples and conducting analysis in a radiochemical laboratory. The cost study indicates that the use of the mobile LA-ICP/AES laboratory results in cost savings of 23% and 40% over traditional field sampling and laboratory analysis conducted by characterization groups at two DOE facilities

Recent developments at the high-field laboratory of Tohoku University

International Nuclear Information System (INIS)

Motokawa, M.; Watanabe, K.; Miura, S.; Awaji, S.; Nojiri, H.; Mogi, I.; Mitsudo, S.; Sakon, T.

1998-01-01

Recent developments and experiments performed at the high-field laboratory of Tohoku University are described. We have (1) hybrid magnets which produce high fields up to 31.1 T, (2) liquid-helium-free superconducting magnets up to 11 T which are available continuously for more than a year, (3) a 20 T superconducting magnet, (4) pulsed field magnets up to 40 T by a 100 kJ bank and (5) repeating pulsed field systems up to 25 T, synchronized with a pulsed neutron source

Research laboratories annual report. 1973 and 1974

International Nuclear Information System (INIS)

1975-02-01

This report presents brief summaries of the research carried out at the Israel A.E.C. laboratories during the two years 1973 and 1974 in the following fields: theoretical physics and chemistry, neutron and reactor physics, solid state physics and metallurgy, laser-induced plasma research, nuclear physics and chemistry, radiation chemistry and applications of radiation and radioisotopes, physical and inorganic chemistry, analytical chemistry, health physics, environmental studies, instrumentation and techniques. (B.G.)

Aedes albopictus (Skuse) males in laboratory and semi-field cages: release ratios and mating competitiveness.

Science.gov (United States)

Madakacherry, Odessa; Lees, Rosemary Susan; Gilles, Jeremie Roger Lionel

2014-04-01

To control the container-breeding mosquito and major vector of dengue and chikungunya Aedes albopictus, the sterile insect technique (SIT) is proposed as a component of integrated vector management programs in endemic areas. For the technique to be successful, released males, sterilized with 35 Gy of ionizing radiation during the pupal stage, must be able to compete for mating opportunities with wild counterparts and successfully copulate with wild females to induce sterility in the population. Any reduction in competitiveness can be compensated for by increasing the ratio of released sterile to wild males, a ratio which must be optimized for effectiveness and efficiency. Fruit fly SIT programs use field enclosures to test the competitiveness of sterile males to monitor the quality of the colony and adjust release ratios. This is laborious and time consuming, and for mosquito programs it would be advantageous if similarly useful results could be obtained by smaller scale laboratory tests, conducted on a more regular basis. In the present study we compared the competitiveness, as measured by hatching rate of resulting egg batches, of irradiated males measured in small and large laboratory cages and semi-field enclosures in a greenhouse setting, when competing in a 1:1, 3:1, and 5:1 ratio with fertile males. The sterile males were found to be equally competitive when compared to unirradiated counterparts, and a 5:1 ratio was sufficient to reduce, but not eliminate, the fertility of the female populations, irrespective of cage size. Variability in hatch rate in eggs laid by individual females and so-called indeterminate matings, when we could not be certain whether a female had mated a fertile or a sterile male, could be investigated by closer investigation of mating status and the frequency of multiple matings in Ae. albopictus. The laboratory results are encouraging for the effectiveness of the SIT using irradiated males of this species, and we support further

PWR radiation fields at combustion engineering plants through mid-1985: Final report

International Nuclear Information System (INIS)

Barshay, S.S.; Beineke, T.A.; Bradshaw, R.W.

1987-01-01

This report presents the results of the initial phase of the EPRI-PWR Standard Radiation Monitoring Program (SRMP) for PWR nuclear power plants with Nuclear Steam Supply Systems supplied by Combustion Engineering, Inc. The purposes of the SRMP are to provide reliable, consistent and systematic measurements of the rate of radiation-field buildup at operating PWR's; and to use that information to identify opportunities for radiation control and the consequent reduction of occupational radiation exposure. The report includes radiation surveys from seven participating power plants. These surveys were conducted at well-defined locations on the reactor coolant loop piping and steam generators, and/or inside the steam generator channel heads. In most cases only one survey is available from each power plant, so that conclusions about the rate of radiation-field buildup are not possible. Some observations are made about the distribution pattern of radiation levels within the steam generator channel heads and around the reactor coolant loops. The report discusses the relationship between out-of-core radiation fields (as measured by the SRMP) and: the pH of the reactor coolant, the concentration of lithium hydroxide in the reactor coolant, and the frequency of changes in reactor power level. In order to provide data for possible future correlations of these parameters with the SRMP radiation-field data, the report summarizes information available from participating plants on primary coolant pH, and on the frequency of changes in reactor power level. 12 refs., 22 figs., 7 tabs

A laboratory and field condition comparison of life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae

Directory of Open Access Journals (Sweden)

Hosseini-Tabesh Behnaz

2015-01-01

Full Text Available Life table studies are essential tools for understanding population dynamics. The life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae feeding on the host plant, Hibiscus syriacus L. were studied under laboratory (25±1°C and relative humidity of 65±5% and a photoperiod of 16L : 8D h and field conditions (23-43°C, and relative humidity of 27-95%. The data were analysed using the age-stage, two-sex life table theory. The life table studies were started with 50 and 40 nymphs in laboratory and field conditions, respectively. Under laboratory conditions, A. gossypii reared on H. syriacus had a higher survival rate, fecundity, and longevity than those reared under field conditions. When reared under field conditions, A. gossypii had a longer nymphal developmental time, shorter adult longevity, and lower fecundity than those reared under laboratory conditions. The intrinsic rate of increase (r, net reproductive rate (R0, and the finite rate of increase (λ under laboratory conditions, were higher than those obtained under field conditions. Nevertheless, there were no significant differences in the mean generation time T (days between field and laboratory conditions. In the present study, the results clearly showed that life table parameters of A. gossypii were significantly different under field and laboratory conditions. These results could help us to understand the A. gossypii population dynamics under field conditions. The results could also help us make better management decisions for economically important crops

Further details on the applicability of Thellier paleointensity method: The effect of magnitude of laboratory field

Science.gov (United States)

Morales, Juan; Goguitchaichvili, Avto; Alva-Valdivia, Luis M.; Urrutia-Fucugauchi, Jaime

2006-06-01

Twenty years after Tanaka and Kono's pioneering contribution (Tanaka and Kono, 1984), we give some new details on the effect of applied field strength during Thellier paleointensity experiments. Special attention is paid to the relation of magnitude of laboratory field and Coe's quality factors (Coe et al., 1978). Full thermoremanent magnetizations were imparted on natural samples containing low-Ti titanomagnetites of pseudo-single domain structure in a 40-μT magnetic field from 600 °C to room temperature. The samples were subjected to the routine Thellier procedure using a wide range of applied laboratory fields. Results indicate that values of laboratory fields may be accurately reproduced within 2% of standard error. The quality factors, however, decrease when the magnitude of 'ancient' field does not match to applied laboratory fields. To cite this article: J. Morales et al., C. R. Geoscience 338 (2006).

Contribution of the radiation hygiene laboratories network in physical protection of radiation materials in Romania

International Nuclear Information System (INIS)

Milu, C.

2002-01-01

Full text: The Ministry of Health and Family from Romania has its own radiation protection network, including 23 radiation hygiene laboratories (RHLs), within the Institutes of Public Health-Bucharest, Iassy, Cluj-Napoca and Timisoara and the Directions of Public Health from Arges county, Bihor, Brasov, Mures, Maramures, Cluj, Sibiu, Harghita, Suceava, lassy, Bacau, Neamt, Galati, Constanta, Prahova, Dolj, Caras-Severin, Timis and Bucharest City. The RHLs network has 170 persons (physicians, physicists, engineers, chemists, biologists and technicians) and it is technically co-ordinated by the RHL in the Institute of Public Health-Bucharest. Within the local or national activities for physical protection of radioactive materials, the RHLs network closely co-operates with the Ministry of Internal Affairs (MAI) and with the nuclear regulatory authority, named the National Commission for Nuclear Activities Control (CNCAN). In the particular case of theft, sabotage or illicit traffic of radioactive materials, usually the MAI has the main role in the co-ordination of intervention actions of the three authorities. The RHLs network contributes by the expertise of its staff and by using its intervention facilities. The specific tasks for the RHLs network are: identification of the type and size of the radioactive material (by direct dosimetry and/or by gamma spectroscopy); dose reconstructions for the involved persons, the intervention personnel and the population; health management for overexposed persons and the medical response, including biological dosimetry and epidemiological studies. Recent special situations in this field, were: theft of some fuel (defect) tablets of natural uranium, from a production factory; the illicit traffic of radioactive materials, in transition to Western European Countries; an unauthorized decommissioning of a furnace, determining the uncontrolled dispersion of about 30 cobalt-60 sealed sources and the radiation exposure of nearly 20

Experiences and Management of Pregnant Radiation Workers at the Pacific Northwest National Laboratory

International Nuclear Information System (INIS)

Bliss, Mary; Bowyer, Sonya M.; Bryant, Janet L.; Lipton, Mary S.; Wahl, Karen L.

2001-01-01

Radiation workers at the Pacific Northwest National Laboratory are divided into two classes based on whether or not they can encounter radioactive contamination in the normal course of their work. Level I workers primarily handle sealed radioactive materials such as those used to calibrate detectors. Level II workers perform benchtop chemistry. The U.S. Department of Energy has strict guidelines on the management of pregnant radiation workers. Staff members may voluntarily notify their line managers of a pregnancy and be subjected to stringent radiation exposure limits for the developing fetus. The staff member and manager develop a plan to limit and monitor radiation dose for the remainder of the pregnancy. Several examples of dose management plans and case examples of the impact of pregnancy on staff member's technical work and projects will be presented

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

Energy Technology Data Exchange (ETDEWEB)

Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

2004-06-01

The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC{sub 50} values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC{sub 50} obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC{sub 50}). This LC{sub 50} value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC{sub 50}. For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC{sub 50} and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC{sub 50} of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC{sub 50} values. In contrast, LC{sub 50} determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature.

Do laboratory salinity tolerances of freshwater animals correspond with their field salinity?

International Nuclear Information System (INIS)

Kefford, Ben J.; Papas, Phil J.; Metzeling, Leon; Nugegoda, Dayanthi

2004-01-01

The degree to which laboratory derived measures of salinity tolerance reflect the field distributions of freshwater biota is uncertain. In this paper we compare laboratory-derived acute salinity tolerance (LC 50 values) of freshwater macroinvertebrates (range 5.5-76 mS/cm) and fish (range 2.7-82 mS/cm) from southeastern Australia with the salinity from which they have been collected in the field. Only 4% of the macroinvertebrates were collected at salinity levels substantially higher than their 72-h LC 50 obtained from directly transferring animals from low salinity water to the water they were tested (direct transfer LC 50 ). This LC 50 value was correlated with the maximum salinity at which a species had been collected. For common macroinvertebrates, the maximum field salinity was approximated by the direct transfer 72-h LC 50 . For adult freshwater fish, 21% of species were collected at salinities substantially greater than their acute direct transfer LC 50 and there was a weak relationship between these two variables. Although there was a weak correlation between the direct transfer LC 50 of early life stages of freshwater fish and the maximum field salinity, 58% of the field distribution were in higher than their LC 50 values. In contrast, LC 50 determined from experiments that acclimated adult fish to higher salinity (slow acclimation) provided a better indication of the field distribution: with only one fish species (7%) being in conflict with their maximum field salinity and a strong positive relationship between these variables. This study shows that laboratory measures of acute salinity tolerance can reflect the maximum salinity that macroinvertebrate and fish species inhabit and are consistent with some anecdotal observations from other studies. - Acute laboratory salinity tolerances relate to maximum salinity where organisms occur in nature

Ways of providing radiation resistance of magnetic field semiconductor sensors

CERN Document Server

Bolshakova, I A; Holyaka, R; Matkovskii, A; Moroz, A

2001-01-01

Hall magnetic field sensors resistant to hard ionizing irradiation are being developed for operation under the radiation conditions of space and in charged particle accelerators. Radiation resistance of the sensors is first determined by the properties of semiconductor materials of sensitive elements; we have used microcrystals and thin layers of III-V semiconductors. Applying complex doping by rare-earth elements and isovalent impurities in certain proportions, we have obtained magnetic field sensors resistant to irradiation by fast neutrons and gamma-quanta. Tests of their radiation resistance were carried out at IBR-2 at the Joint Institute for Nuclear Research (Dubna). When exposed to neutrons with E=0.1-13 MeV and intensity of 10 sup 1 sup 0 n cm sup - sup 2 s sup - sup 1 , the main parameter of the sensors - their sensitivity to magnetic fields - changes by no more than 0.1% up to fluences of 10 sup 1 sup 4 n cm sup - sup 2. Further improvement of radiation resistance of sensor materials is expected by ...

The right choice: extremity dosemeter for different radiation fields

International Nuclear Information System (INIS)

Brasik, N.; Stadtmann, H.; Kindl, P.

2005-01-01

Full text: Measurements of weakly penetrating radiation in personal dosimetry present problems in the design of suitable detectors and in the interpretation of their readings. For the measurement of the individual beta radiation dose, personal dosemeter for the fingers/tips are required. In general, the dosemeters currently used for personal monitoring of beta and low energy photon doses suffer from an energy threshold problem because the detector and/or the filter are too thick. TLDs of a standard thickness can seriously underestimate personal skin doses, especially in external fields of weakly penetrating radiation fields. LiF:Mg, Cu, P is a promising TL material which allows the production of thin detectors with sufficient sensitivity. Dosimetric properties of two different types of extremity dosemeters, designed to measure the personal dose equivalent Hp(0.07), have been compared: LiF:Mg, Ti (TLD100) and LiF:Mg, Cu, P (TLD700H). The first one consists of 100 mg.cm -2 LiF:Mg, Ti (TLD 100) chip and a 35mg. cm -2 cap, the other consists of a 7mg. cm -2 layer of LiF:Mg, Cu, P (TLD-700H) powder and a 5mg. cm -2 cap. The evaluation was done in two steps: performance tests (ISO-12794) and measurements in real workplaces. In the first step type test results for beta calibration were compared. In addition calibration for low energy photon radiation according to ISO 4037-3 was carried out. In the second step, simultaneous measurements with both types of dosemeters were performed at workplaces, where radiopharmaceuticals containing different radioisotopes are prepared and applied. Practices in these fields are characterized by handling of high activities at very small distances between source and skin. The results from the comparison of the two dosemeter types are presented and analyzed with respect to different radiation fields. Experiments showed a satisfactory sensitivity for the thinner dosemeter (TLD 700H) for detecting beta radiation at protection levels and a good

Use of synchrotron radiation in radiation biology research

International Nuclear Information System (INIS)

Yamada, Takeshi

1981-01-01

Synchrotron radiation (SR) holds great expectation as a new research tool in the new areas of material science, because it has the continuous spectral distribution from visible light to X-ray, and its intensity is 10 2 to 10 3 times as strong as that of conventional radiation sources. In the National Laboratory for High Energy Physics, a synchrotron radiation experimental facility has been constructed, which will start operation in fiscal 1982. With this SR, the photons having the wavelength in undeveloped region from vacuum ultraviolet to soft X-ray are obtained as intense mono-wavelength light. The SR thus should contribute to the elucidation of the fundamentals in the biological action of radiation. The following matters are described: synchrotron radiation, experimental facility using SR, electron storage ring, features of SR, photon factory plan and synchrotron radiation experimental facility, utilization of SR in radiation biology field. (J.P.N.)

DEVELOPMENT HISTORY OF NATURAL SOURCES DOSIMETRY LABORATORY AT THE RESEARCH INSTITUTE OF RADIATION HYGIENE AFTER PROFESSOR P.V. RAMZAEV: 1970–1986

Directory of Open Access Journals (Sweden)

E. P. Lisachenko

2016-01-01

Full Text Available At the initial development stage of the Leningrad Research Institute of Radiation Hygiene natural sources dosimetry laboratory the experts focused at establishment of equipment and methodology. The following period of the lab activity was rather related to theoretical and experimental research which finally led to creation of a new in radiation hygiene field of work on standard protection of population irradiation caused by natural sources of ionizing radiation. The article describes the main results of the laboratory research of construction materials natural radioactivity and the subsequent substantiation of specifications on natural radionuclides content in them. There was parallel research of natural radionuclides transfer in the system “fertilizers→soil→plants” and further along the nutrition chain into the human body. In these works there were first obtained the quantitative data on coefficients of natural radionuclides transfer from fertilizers into agricultural plants, data on the natural radionuclides content in phosphate fertilizers of the main manufacturers, and the reference data on the natural radioactivity of arable soils. This research provided substantiation of a standard of natural radionuclides content in phosphate fertilizers. Important results were also received in a large-scale research of natural environment radioactivity and of technological processes of production, processing and use of mineral raw materials. During this research for the first time there were obtained the tool data on irradiation levels and structure of doses of non-uranium industries enterprises’ employees and on natural radionuclides balance parameters in different technologies.For the last two years of the considered period the laboratory was practically not engaged in its primary activity – the efforts of all laboratory and the Institute experts were focused at analysis of Chernobyl NPP accident consequences, research of man

Constraining Carbonaceous Aerosol Climate Forcing by Bridging Laboratory, Field and Modeling Studies

Science.gov (United States)

Dubey, M. K.; Aiken, A. C.; Liu, S.; Saleh, R.; Cappa, C. D.; Williams, L. R.; Donahue, N. M.; Gorkowski, K.; Ng, N. L.; Mazzoleni, C.; China, S.; Sharma, N.; Yokelson, R. J.; Allan, J. D.; Liu, D.

2014-12-01

Biomass and fossil fuel combustion emits black (BC) and brown carbon (BrC) aerosols that absorb sunlight to warm climate and organic carbon (OC) aerosols that scatter sunlight to cool climate. The net forcing depends strongly on the composition, mixing state and transformations of these carbonaceous aerosols. Complexities from large variability of fuel types, combustion conditions and aging processes have confounded their treatment in models. We analyse recent laboratory and field measurements to uncover fundamental mechanism that control the chemical, optical and microphysical properties of carbonaceous aerosols that are elaborated below: Wavelength dependence of absorption and the single scattering albedo (ω) of fresh biomass burning aerosols produced from many fuels during FLAME-4 was analysed to determine the factors that control the variability in ω. Results show that ω varies strongly with fire-integrated modified combustion efficiency (MCEFI)—higher MCEFI results in lower ω values and greater spectral dependence of ω (Liu et al GRL 2014). A parameterization of ω as a function of MCEFI for fresh BB aerosols is derived from the laboratory data and is evaluated by field data, including BBOP. Our laboratory studies also demonstrate that BrC production correlates with BC indicating that that they are produced by a common mechanism that is driven by MCEFI (Saleh et al NGeo 2014). We show that BrC absorption is concentrated in the extremely low volatility component that favours long-range transport. We observe substantial absorption enhancement for internally mixed BC from diesel and wood combustion near London during ClearFlo. While the absorption enhancement is due to BC particles coated by co-emitted OC in urban regions, it increases with photochemical age in rural areas and is simulated by core-shell models. We measure BrC absorption that is concentrated in the extremely low volatility components and attribute it to wood burning. Our results support

78 FR 55763 - National Environmental Policy Act; Santa Susana Field Laboratory

Science.gov (United States)

2013-09-11

... document format at http://www.nasa.gov/agency/nepa/news/SSFL.html . The Federal Register Notice of Intent...; Santa Susana Field Laboratory AGENCY: National Aeronautics and Space Administration (NASA). ACTION... Demolition and Environmental Cleanup Activities for the NASA-administered portion of the Santa Susana Field...

Laboratory and field experience with rim ditch dewatering of MFT

Energy Technology Data Exchange (ETDEWEB)

Demoz, A.; Mikula, R. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre; Lahaie, R. [Syncrude Canada Ltd., Edmonton, AB (Canada)

2010-07-01

This PowerPoint presentation described a rim ditch method of dewatering mature fine tailings (MFT). Polymer additions were used to strengthen the MFT and to decrease the capillary suction time (CST). Laboratory and field-scale studies were conducted to demonstrate the dewatering method. The flocculants were added in a Komax inline mixer. Polymers were then injected into the tailings. The mixing processes were optimized in a series of laboratory studies and then demonstrated in the field tests. The tests showed that CST and high dewatering rates were consistently maintained using the method. MFT feeds were also consistent. Release water quality was improved using the method. The large-scale test site is now being monitored for compliance with Directive 74. tabs., figs.

CERN radiation protection (RP) calibration facilities

Energy Technology Data Exchange (ETDEWEB)

Pozzi, Fabio

2016-04-14

Radiation protection calibration facilities are essential to ensure the correct operation of radiation protection instrumentation. Calibrations are performed in specific radiation fields according to the type of instrument to be calibrated: neutrons, photons, X-rays, beta and alpha particles. Some of the instruments are also tested in mixed radiation fields as often encountered close to high-energy particle accelerators. Moreover, calibration facilities are of great importance to evaluate the performance of prototype detectors; testing and measuring the response of a prototype detector to well-known and -characterized radiation fields contributes to improving and optimizing its design and capabilities. The CERN Radiation Protection group is in charge of performing the regular calibrations of all CERN radiation protection devices; these include operational and passive dosimeters, neutron and photon survey-meters, and fixed radiation detectors to monitor the ambient dose equivalent, H*(10), inside CERN accelerators and at the CERN borders. A new state-of-the-art radiation protection calibration facility was designed, constructed and commissioned following the related ISO recommendations to replace the previous ageing (more than 30 years old) laboratory. In fact, the new laboratory aims also at the official accreditation according to the ISO standards in order to be able to release certified calibrations. Four radiation fields are provided: neutrons, photons and beta sources and an X-ray generator. Its construction did not only involve a pure civil engineering work; many radiation protection studies were performed to provide a facility that could answer the CERN calibration needs and fulfill all related safety requirements. Monte Carlo simulations have been confirmed to be a valuable tool for the optimization of the building design, the radiation protection aspects, e.g. shielding, and, as consequence, the overall cost. After the source and irradiator installation

Comparison of field-measured radon diffusion coefficients with laboratory-measured coefficients

International Nuclear Information System (INIS)

Lepel, E.A.; Silker, W.B.; Thomas, V.W.; Kalkwarf, D.R.

1983-04-01

Experiments were conducted to compare radon diffusion coefficients determined for 0.1-m depths of soils by a steady-state method in the laboratory and diffusion coefficients evaluated from radon fluxes through several-fold greater depths of the same soils covering uranium-mill tailings. The coefficients referred to diffusion in the total pore volume of the soils and are equivalent to values for the quantity, D/P, in the Generic Environmental Impact Statement on Uranium Milling prepared by the US Nuclear Regulatory Commission. Two soils were tested: a well-graded sand and an inorganic clay of low plasticity. For the flux evaluations, radon was collected by adsorption on charcoal following passive diffusion from the soil surface and also from air recirculating through an aluminum tent over the soil surface. An analysis of variance in the flux evaluations showed no significant difference between these two collection methods. Radon diffusion coefficients evaluated from field data were statistically indistinguishable, at the 95% confidence level, from those measured in the laboratory; however, the low precision of the field data prevented a sensitive validation of the laboratory measurements. From the field data, the coefficients were calculated to be 0.03 +- 0.03 cm 2 /s for the sand cover and 0.0036 +- 0.0004 cm 2 /s for the clay cover. The low precision in the coefficients evaluated from field data was attributed to high variation in radon flux with time and surface location at the field site

Research and development in the field of radiation curable coating systems

International Nuclear Information System (INIS)

Demmler, K.; Goethlich, L.; Osterloh, R.; Zosel, A.

1977-08-01

Suitable monomers for radiation curable coatings are mono- and polyfunctional acrylates and N vinylcompounds like vinylpyrrolidone and divinylpropyleneurea. Methacrylates, vinylesters and vinylethers are less suited. The residual monomer content of two completely cured coatings (UP and epoxyacrylate resins) amounts to 0.01 to 0.05%. Electron beam cured UP/acrylate films are particularly soil resistant. Peroxide and electron beam cured UP resin coatings differ in their curing pattern. Development of radiation sources now allows for testing radiation curable coatings on laboratory units. Modern EB and UV radiators deliver comparable results. The patent literature on electron beam curing comprises more than 700 known applications. In the course of the work described herein 4 patents were applied for. (orig.) [de

Use of an electric field in an electrostatic liquid film radiator.

Science.gov (United States)

Bankoff, S G; Griffing, E M; Schluter, R A

2002-10-01

Experimental and numerical work was performed to further the understanding of an electrostatic liquid film radiator (ELFR) that was originally proposed by Kim et al.(1) The ELFR design utilizes an electric field that exerts a normal force on the interface of a flowing film. The field lowers the pressure under the film in a space radiator and, thereby, prevents leakage through a puncture in the radiator wall. The flowing film is subject to the Taylor cone instability, whereby a cone of fluid forms underneath an electrode and sharpens until a jet of fluid is pulled toward the electrode and disintegrates into droplets. The critical potential for the instability is shown to be as much as an order of magnitude higher than that used in previous designs.(2) Furthermore, leak stoppage experiments indicate that the critical field is adequate to stop leaks in a working radiator.

Conception of the Instrument Calibration Laboratory of Ionizing Radiation Measurement (LACIMRI) of CTMSP - Sao Paulo, SP

International Nuclear Information System (INIS)

Silva, Raimundo Dias da; Kibrit, Eduardo

2009-01-01

The present work describes the phases of implantation of calibration laboratory of ionizing radiation measurement instruments at the CTMSP, Sao Paulo, in a priory approved by CNEN, Brazil. That laboratory will allow and enhance the present metrological capacity for the attendance to the growing demand for calibration services of the instruments

Review of radiation sources, calibration facilities and simulated workplace fields

Energy Technology Data Exchange (ETDEWEB)

Lacoste, V., E-mail: veronique.lacoste@irsn.f [Institut de Radioprotection et de Surete Nucleaire, BP3, Bat. 159, F-13115 Saint-Paul Lez Durance (France)

2010-12-15

A review on radiation sources, calibration facilities and realistic fields is presented and examples are given. The main characteristics of the fields are shortly described together with their domain of applications. New emerging fields are also mentioned and the question of needs for additional calibration fields is raised.

Synchrotron radiation

CERN Document Server

Kunz, C

1974-01-01

The production of synchrotron radiation as a by-product of circular high-energy electron (positron) accelerators or storage rings is briefly discussed. A listing of existing or planned synchrotron radiation laboratories is included. The following properties are discussed: spectrum, collimation, polarization, and intensity; a short comparison with other sources (lasers and X-ray tubes) is also given. The remainder of the paper describes the experimental installations at the Deutsches Elektronen-Synchrotron (DESY) and DORIS storage rings, presents a few typical examples out of the fields of atomic, molecular, and solid-state spectroscopy, and finishes with an outlook on the use of synchrotron radiation in molecular biology. (21 refs).

Spectral tuning of near-field radiative heat transfer by graphene-covered metasurfaces

Science.gov (United States)

Zheng, Zhiheng; Wang, Ao; Xuan, Yimin

2018-03-01

When two gratings are respectively covered by a layer of graphene sheet, the near-field radiative heat transfer between two parallel gratings made of silica (SiO2) could be greatly improved. As the material properties of doped silicon (n-type doping concentration is 1020 cm-3, marked as Si-20) and SiO2 differ greatly, we theoretically investigate the near-field radiative heat transfer between two parallel graphene-covered gratings made of Si-20 to explore some different phenomena, especially for modulating the spectral properties. The radiative heat flux between two parallel bulks made of Si-20 can be enhanced by using gratings instead of bulks. When the two gratings are respectively covered by a layer of graphene sheet, the radiative heat flux between two gratings made of Si-20 can be further enhanced. By tuning graphene chemical potential μ and grating filling factor f, due to the interaction between surface plasmon polaritons (SPPs) of graphene sheets and grating structures, the spectral properties of the radiative heat flux between two parallel graphene-covered gratings can be effectively regulated. This work will develop and supplement the effects of materials on the near-field radiative heat transfer for this kind of system configuration, paving a way to modulate the spectral properties of near-field radiative heat transfer.

Magnetic resonance in medicine occupational exposure to static magnetic field and radiofrequency radiation

International Nuclear Information System (INIS)

Zivkovic, D.; Hrnjak, M.; Ivanovic, C.

1997-01-01

Medical personnel working with magnetic resonance imaging (MRI) devices could be exposed to static magnetic (M) field, time-varying M fields and radiofrequency (RF) radiation. The aim of work was to investigate the density of magnetic flux of static magnetic field and the power density of RF radiation which appear in the working environment around the 0.5 T MRI unit in one hospital. The density of magnetic flux of static magnetic field was measured with Hall Effect Gauss meter - Magnetech (Great Britain), and the power density of RF radiation was measured with broadband isotropic meter - The Narda Microwave Corp. (USA). The results of measurement show that the density of magnetic flux of static M field on working places are below threshold limit of exposure and the intensities of RF radiation are far below maximum permissible level. (author)

Nuclear analysis methods. Rudiments of radiation protection

International Nuclear Information System (INIS)

Roth, E.

1998-01-01

The nuclear analysis methods are generally used to analyse radioactive elements but they can be used also for chemical analysis, with fields such analysis and characterization of traces. The principles of radiation protection are explained (ALARA), the biological effects of ionizing radiations are given, elements and units used in radiation protection are reminded in tables. A part of this article is devoted to how to use radiation protection in a nuclear analysis laboratory. (N.C.)

Effect of ionization radiation (γ-rays 60Co) on germination of cotton

International Nuclear Information System (INIS)

Lall, S.B.; Bhute, M.G.

1974-01-01

Effect of ionization radiation (γ-rays 60 Co) on germination of cotton varieties viz. AK 235 and 197/3, also B 147 and B 296-7 belonging to Gossypium arboreum and Gossypium hirsutum respectively under field and laboratory conditions were studied. Materials under study were tried in two radiation doses i.e. 10,000 r and 20,000 r in two (R1 and R2) generations. In laboratory and field condition, both doses (10,000r and 20,000r) depressed the germination percentage in R1 generation of radiation to greater degree in almost all the varieties of cotton. Maximum depression was noted under field condition in both the varieties belonging to Gossypium arboreum species in R1 generation under 20,000 r. In R2 generation, depressing effect on germination capacity of seed is reduced to much extent in field condition in almost of all the varieties. The germination percentage has increased over control in R2 generation in both doses in laboratory conditions in all the varieties used in this experiment. (author)

New theory of radiative energy transfer in free electromagnetic fields

International Nuclear Information System (INIS)

Wolf, E.

1976-01-01

A new theory of radiative energy transfer in free, statistically stationary electromagnetic fields is presented. It provides a model for energy transport that is rigorous both within the framework of the stochastic theory of the classical field as well as within the framework of the theory of the quantized field. Unlike the usual phenomenological model of radiative energy transfer that centers around a single scalar quantity (the specific intensity of radiation), our theory brings into evidence the need for characterizing the energy transport by means of two (related) quantities: a scalar and a vector that may be identified, in a well-defined sense, with ''angular components'' of the average electromagnetic energy density and of the average Poynting vector, respectively. Both of them are defined in terms of invariants of certain new electromagnetic correlation tensors. In the special case when the field is statistically homogeneous, our model reduces to the usual one and our angular component of the average electromagnetic energy density, when multiplied by the vacuum speed of light, then acquires all the properties of the specific intensity of radiation. When the field is not statistically homogeneous our model approximates to the usual phenomenological one, provided that the angular correlations between plane wave modes of the field extend over a sufficiently small solid angle of directions about the direction of propagation of each mode. It is tentatively suggested that, when suitably normalized, our angular component of the average electromagnetic energy density may be interpreted as a quasi-probability (general quantum-mechancial phase-space distribution function, such as Wigner's) for the position and the momentum of a photon

Application of gamma radiation for the treatment of laboratory animal diets

International Nuclear Information System (INIS)

Ley, F.J.

1979-01-01

The use of gamma radiation for the treatment of laboratory animal diets has proved particularly successful. The effective inactivation of microorganisms, insects and parasites etc. is well demonstrated and the absence of adverse effects on the dietary components is inferred from many years of practical use. Adequate packaging of the pelleted diets is essential to avoid recontamination after irradiation; this aspect needs particular attention. The economics of the process are such that it would not be warranted to invest in a 60 Co plant specifically for the treatment of laboratory diets. However, a throughput in the order of 1000 to 1500 tonnes per annum, as estimated to meet UK current demand, can be catered for adequately and economically in a large-scale general service facility. (author)

Low-frequency electromagnetic radiation field interaction with cerebral nervous MT

International Nuclear Information System (INIS)

Gao Feng; Zhou Yi; Xiao Detao; Zhang Dengyu

2009-01-01

We investigate the interaction characteristics and mechanism of electromagnetic radiation field and cerebral nervous system. When the electromagnetic radiation is non-ionization low-frequency electromagnetic field, the two-state physical system in the cytoskeletal microtubule (MT) can be quantized. The state of information bits in cerebral neurons system is described by density matrix, and the system dynamics equation is established and solved. It indicates that when the brain is exposed to non-ionization low-frequency electromagnetic field, the density matrix non-opposite angle element of cerebral nervous qubit will never be zero, its quantum coherence characteristic can keep well, and the brain function will also be not damaged. (authors)

The Electromagnetic Dipole Radiation Field through the Hamiltonian Approach

Science.gov (United States)

Likar, A.; Razpet, N.

2009-01-01

The dipole radiation from an oscillating charge is treated using the Hamiltonian approach to electrodynamics where the concept of cavity modes plays a central role. We show that the calculation of the radiation field can be obtained in a closed form within this approach by emphasizing the role of coherence between the cavity modes, which is…

The mismatch between bioaccumulation in field and laboratory environments: Interpreting the differences for metals in benthic bivalves

International Nuclear Information System (INIS)

Belzunce-Segarra, Maria J.; Simpson, Stuart L.; Amato, Elvio D.; Spadaro, David A.; Hamilton, Ian L.; Jarolimek, Chad V.; Jolley, Dianne F.

2015-01-01

Laboratory-based bioaccumulation and toxicity bioassays are frequently used to predict the ecological risk of contaminated sediments in the field. This study investigates the bioassay conditions most relevant to achieving environmentally relevant field exposures. An identical series of metal-contaminated marine sediments were deployed in the field and laboratory over 31 days. Changes in metal concentrations and partitioning in both sediments and waters were used to interpret differences in metal exposure and bioaccumulation to the benthic bivalve Tellina deltoidalis. Loss of resuspended sediments and deposition of suspended particulate matter from the overlying water resulted in the concentrations of Cu, Pb and Zn (major contaminants) becoming lower in the 1-cm surface layer of field-deployed sediments. Lower exchange rates of overlying waters in the laboratory resulted in higher dissolved metal exposures. The prediction of metal bioaccumulation by the bivalves in field and laboratory was improved by considering the metal partitioning within the surface sediments. - Highlights: • Particulate metals are the dominant metal exposure route in laboratory and field tests (87). • There is an over-representation of the dissolved metal exposure in the laboratory (81). • Laboratory bioassays result in higher bioaccumulation of major metals, Cu, Pb, Zn (82). • Differences in exposure must be considered for a proper sediment quality evaluation (83). • Traditional measurements are not sufficient to explain bioaccumulation results (79). - To improve the value of field- and laboratory-based sediment bioassays in ecological risk assessments, it is necessary to create exposure conditions that resemble those in the field

Analysis of radiation pneumonitis outside the radiation field in breast conserving therapy for early breast cancer

International Nuclear Information System (INIS)

Ogo, Etsuyo; Fujimoto, Kiminori; Hayabuchi, Naofumi

2002-01-01

In a retrospective study of radiation-induced pulmonary changes for patients with breast conserving therapy for early breast cancer, we sent questionnaires to the main hospitals in Japan. In this study, we analyzed pulmonary changes after tangential whole-breast irradiation. The purpose of this study was to determine the incidence and risk factors for radiation pneumonitis outside the radiation field. The questionnaires included patients data, therapy data, and lung injury information between August 1999 and May 2000. On the first questionnaires, answer letters were received from 107 institutions out of 158 (67.7%). On the second questionnaires, response rate (hospitals which had radiation pneumonitis outside the radiation field) was 21.7% (23/106). We could find no risk factors of this type of pneumonitis. We suggested that lung irradiation might trigger this type of pneumonitis which is clinically similar to BOOP (bronchiolitis obliterans organizing pneumonia). It developed in 1.5-2.1% among the patients with breast conserving surgery and tangential whole-breast irradiation. And it is likely appeared within 6 months after radiotherapy. (author)

Radiation Characterization Summary: ACRR Central Cavity Free-Field Environment with the 32-Inch Pedestal at the Core Centerline (ACRR-FF-CC-32-cl).

Energy Technology Data Exchange (ETDEWEB)

Vega, Richard Manuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Parma, Edward J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Naranjo, Gerald E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lippert, Lance L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vehar, David W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Griffin, Patrick J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-08-01

This document presents the facilit y - recommended characteri zation o f the neutron, prompt gamma - ray, and delayed gamma - ray radiation fields in the Annular Core Research Reactor ( ACRR ) for the cen tral cavity free - field environment with the 32 - inch pedestal at the core centerline. The designation for this environmen t is ACRR - FF - CC - 32 - cl. The neutron, prompt gamma - ray , and delayed gamma - ray energy spectra , uncertainties, and covariance matrices are presented as well as radial and axial neutron and gamma - ray fluence profiles within the experiment area of the cavity . Recommended constants are given to facilitate the conversion of various dosimetry readings into radiation metrics desired by experimenters. Representative pulse operations are presented with conversion examples . Acknowledgements The authors wish to th ank the Annular Core Research Reactor staff and the Radiation Metrology Laboratory staff for their support of this work . Also thanks to David Ames for his assistance in running MCNP on the Sandia parallel machines.

Effects of hypersonic field and anharmonic interactions on channelling radiation

International Nuclear Information System (INIS)

George, Juby; Pathak, Anand P; Goteti, L N S Prakash; Nagamani, G

2007-01-01

The effects of a hypersonic field on positron channelling radiation are considered. Anharmonic effects of the transverse potential induced by these longitudinal fields are incorporated and the wavefunction of the planar channelled positron is found by the solution of Dirac equation under the resonant influence of hypersound. An expression for the resonant frequency is estimated. The transition probabilities and the intensity of the channelling radiation are also calculated. It is found that the anharmonic effects change the spectral distributions considerably

The central gamma spectrometry laboratory of the GSF Institute of Radiation Protection

International Nuclear Information System (INIS)

Ruckerbauer, F.; Dietl, F.; Winkler, R.

1997-01-01

Since the middle of 1995 the WG Radioecology is operating the central gamma spectrometry laboratory of the GSF-Institute of Radiation Protection. The main scope of the laboratory is the gamma spectrometric analysis of samples within the research program of the institute and within joint programs with other institutes of the GSF research center. In the present report set-up and technical data of the measuring equipment, the central operating and data evaluation system and measures for quality assurance are described. At that time 18 semiconductor detectors are available for gamma spectrometric sample analysis which is standardized with respect to operation, evaluation algorithms, nuclide data, data safety and documentation. (orig.) [de

Regulatory inspections in nuclear plants in the field of radiation protection

International Nuclear Information System (INIS)

Hort, M.; Fuchsova, D.

2014-01-01

State Office for Nuclear Safety executes state administration and performs inspections at peaceful use of nuclear energy and ionizing radiation in the field of radiation protection and nuclear safety. Inspections on radiation protection at nuclear power plants are secured by inspectors of the Department of Radiation Protection in Fuel Cycle, who work at the Regional centre Brno and Ceske Budejovice. (authors)

Radiation resistance of elastomeric O-rings in mixed neutron and gamma fields: Testing methodology and experimental results

Science.gov (United States)

Zenoni, A.; Bignotti, F.; Donzella, A.; Donzella, G.; Ferrari, M.; Pandini, S.; Andrighetto, A.; Ballan, M.; Corradetti, S.; Manzolaro, M.; Monetti, A.; Rossignoli, M.; Scarpa, D.; Alloni, D.; Prata, M.; Salvini, A.; Zelaschi, F.

2017-11-01

Materials and components employed in the presence of intense neutron and gamma fields are expected to absorb high dose levels that may induce deep modifications of their physical and mechanical properties, possibly causing loss of their function. A protocol for irradiating elastomeric materials in reactor mixed neutron and gamma fields and for testing the evolution of their main mechanical and physical properties with absorbed dose has been developed. Four elastomeric compounds used for vacuum O-rings, one fluoroelastomer polymer (FPM) based and three ethylene propylene diene monomer rubber (EPDM) based, presently available on the market have been selected for the test. One EPDM is rated as radiation resistant in gamma fields, while the other elastomers are general purpose products. Particular care has been devoted to dosimetry calculations, since absorbed dose in neutron fields, unlike pure gamma fields, is strongly dependent on the material composition and, in particular, on the hydrogen content. The products have been tested up to about 2 MGy absorbed dose. The FPM based elastomer, in spite of its lower dose absorption in fast neutron fields, features the largest variations of properties, with a dramatic increase in stiffness and brittleness. Out of the three EPDM based compounds, one shows large and rapid changes in the main mechanical properties, whereas the other two feature more stable behaviors. The performance of the EPDM rated as radiation resistant in pure gamma fields does not appear significantly better than that of the standard product. The predictive capability of the accelerated irradiation tests performed as well as the applicable concepts of threshold of radiation damage is discussed in view of the use of the examined products in the selective production of exotic species facility, now under construction at the Legnaro National Laboratories of the Italian Istituto Nazionale di Fisica Nucleare. It results that a careful account of dose rate effects

Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Executive summary

International Nuclear Information System (INIS)

Jacob, P.; Paretzke, H.G.; Roth, P.

2000-01-01

The Association Contract covers a range of research domains that are important to the Radiation Protection Research Action, especially in the areas 'Evaluation of Radiation Risks' and 'Understanding Radiation Mechanisms and Epidemiology'. Three research projects concentrate on radiation dosimetry research and two projects on the modelling of radiation carcinogenesis. The following list gives an overview on the topics and responsible scientific project leaders of the Association Contract: Study of radiation fields and dosimetry at aviation altitudes. Biokinetics and dosimetry of incorporated radionuclides. Dose reconstruction. Biophysical models for the induction of cancer by radiation. Experimental data for the induction of cancer by radiation of different qualities. (orig.)

The Influence of the Non-Ionizing Electromagnetic Fields of a high Voltage overhead lines on the human being (Biological laboratory study)

International Nuclear Information System (INIS)

Mobadda, SH.; Rayes, M.; Sleman, A.

2009-01-01

Many laboratory studies had been carried out on the effect of electromagnetic fields with non-ionized radiations of the H V alternative lines on human beings late in the past century in many European countries and in the United States of America. However, such studies are still running in order to contribute beside the statistical studies in illustrating such effect.Those laboratory studies were made on animals like rats, mice and monkeys having similar tissues to man. They were subjected to electromagnetic fields with variable frequency electric power system and for different intervals or on volunteers, though very few of course, since international laws forbid it. In our surrounding, a specific and unique case is available, i.e. many people are living directly under H V lines. Consequently, they are susceptible to the fields of such lines for long periods of time up to over thirty years and to various voltages subject to the location of their lodges under the transmission lines. Thus, it has made available an appropriate surrounding to conduct a bio-laboratory hematic study on different specimens of inhabitants in terms of sex and age category. These specimens are compared with those of non-inhabitants but within the same environmental conditions. This study is conducted in collaboration with specialists from the Faculty of Medicine and Al-Mouassat Hospital -Damascus University. Clear and useful findings and indices have been obtained. (author)

The erosion of carbonate stone by acid rain: Laboratory and field investigations

International Nuclear Information System (INIS)

Baedecker, P.A.; Reddy, M.M.

1993-01-01

This paper describes a laboratory experiment on the effects of acidic deposition on carbonate stone erosion. It can serve as the basis for an undergraduate (or pre college) experiment in environmental chemistry. Recent field investigations are described that provide measurements of carbonate stone dissolution and mechanical erosion under weathering conditions that are prevalent in the eastern US. The purpose of the laboratory work is to answer questions concerning the effects of hydrogen ion deposition on stone erosion processes that were difficult to resolve on the basis of field experiments alone

Informatics for the solution of health physics problems in nuclear medicine laboratories

International Nuclear Information System (INIS)

De Rossi, G.; Montesanti, M.I.

1984-01-01

As the use of 'in vitro' and 'in vivo' radioisotope studies spreads more and more, many organizational and management problems arise. Hence an exact evaluation of current contamination levels and protection standards is very important for radiation-protection purposes. Environmental and personnel contamination levels in Nuclear Medicine Laboratories were recorded for four years and the results were evaluated by a computer-assisted method which furnished parameters such as the maximum permissible level of radioactivity at different timeintervals. They allow the health physicist to assess laboratory contamination levels as well as to classify radiation workers and places. A continuous 'monitoring' of radiation safety is possible in order to modify worker and/or laboratory classification as soon as possible, in close connection with possible changes in radiation hazards. This computer program applies equally well to other fields involving radioisotope use, such as industry, agriculture, etc. (Author)

Development of methods to control radiation field and corrosion in PHWRS

International Nuclear Information System (INIS)

Velmurugan, S.

2015-01-01

Pressurized Heavy Water Reactors (PHWRs) is the mainstay of Indian Nuclear Power Program. There are 18 PHWRs (220 MWe and 540 MWe) in operation and 4 X 700 MWe PHWRs are under construction. In these reactors, as far as radiation field is concerned, the philosophy of ALARA (As Low As Reasonably Achievable) is followed. The primary coolant system chemistry control is given due consideration during operation so that corrosion of structural material is minimized which in turn controls the radiation field. Development and application of full system Dilute Chemical Decontamination (DCD) process helped to reduce the radiation field in MAPS-1 and 2, RAPS-1 and 2, NAPS-1 and 2 and KAPS-1. PHWR being a tube type reactor, it enables application of full system decontamination to its heavy water primary coolant system. Significant reduction in radiation field and consequent savings in MANREM could be achieved. Attempts are being made to understand the problem created by the release of antimony activities ( 122 Sb and 124 Sb) during chemical decontamination and during planned shutdown. Passivation as a method to control the radiation field and corrosion is being studied. Magnesium ion as a passivator to the ferrite filmed structural materials of PHWRs is being investigated. In addition, as PHWRs uses carbon steel as structural material, the use of passivation as a method to control flow accelerated corrosion (FAC) is also being studied. Magnesium ion gets incorporated in the ferrite film formed over carbon steel structural material and is expected to reduce the solubility of magnetite film thereby the FAC of feeders in PHWRs. (author)

Radiation of Electron in the Field of Plane Light Wave

International Nuclear Information System (INIS)

Zelinsky, A.; Drebot, I.V.; Grigorev, Yu.N.; Zvonareva, O.D.; Tatchyn, R.

2006-01-01

Results of integration of a Lorentz equation for a relativistic electron moving in the field of running, plane, linear polarized electromagnetic wave are presented in the paper. It is shown that electron velocities in the field of the wave are almost periodic functions of time. For calculations of angular spectrum of electron radiation intensity expansion of the electromagnetic field in a wave zone into generalized Fourier series was used. Expressions for the radiation intensity spectrum are presented in the paper. Derived results are illustrated for electron and laser beam parameters of NSC KIPT X-ray generator NESTOR. It is shown that for low intensity of the interacting electromagnetic wave the results of energy and angular spectrum calculations in the frame of classical electrodynamics completely coincide with calculation results produced using quantum electrodynamics. Simultaneously, derived expressions give possibilities to investigate dependence of energy and angular Compton radiation spectrum on phase of interaction and the interacting wave intensity

Combined equations for estimating global solar radiation: Projection of radiation field over Japan under global warming conditions by statistical downscaling

International Nuclear Information System (INIS)

Iizumi, T.; Nishimori, M.; Yokozawa, M.

2008-01-01

For this study, we developed a new statistical model to estimate the daily accumulated global solar radiation on the earth's surface and used the model to generate a high-resolution climate change scenario of the radiation field in Japan. The statistical model mainly relies on precipitable water vapor calculated from air temperature and relative humidity on the surface to estimate seasonal changes in global solar radiation. On the other hand, to estimate daily radiation fluctuations, the model uses either a diurnal temperature range or relative humidity. The diurnal temperature range, calculated from the daily maximum and minimum temperatures, and relative humidity is a general output of most climate models, and pertinent observation data are comparatively easy to access. The statistical model performed well when estimating the monthly mean value, daily fluctuation statistics, and regional differences in the radiation field in Japan. To project the change in the radiation field for the years 2081 to 2100, we applied the statistical model to the climate change scenario of a high-resolution Regional Climate Model with a 20-km mesh size (RCM20) developed at the Meteorological Research Institute based on the Special Report for Emission Scenario (SRES)-A2. The projected change shows the following tendency: global solar radiation will increase in the warm season and decrease in the cool season in many areas of Japan, indicating that global warming may cause changes in the radiation field in Japan. The generated climate change scenario for the radiation field is linked to long-term and short-term changes in air temperature and relative humidity obtained from the RCM20 and, consequently, is expected to complement the RCM20 datasets for an impact assessment study in the agricultural sector

Intercomparison exercise on external gamma dose rate under field conditions at the laboratory of natural radiation (Saelices el Chico, Spain)

International Nuclear Information System (INIS)

Gutierrez-Villanueva, J. L.; Sainz-Fernandez, C.; Fuente-Merino, I.; Saez-Vergara, J. C.; Correa-Garce, E.; Quindos-Poncela, L. S.

2013-01-01

The last nuclear accident in Fukushima nuclear power plant has increased the necessity for measuring radiation in the environment. Therefore, radiation monitors providing results traceable throughout the country become essential and it is very important to test them under the same environmental conditions. The first intercomparison of natural radioactivity under field conditions was held in Saelices el Chico (Salamanca, Spain) in May 2011, including an exercise on environmental dose rate. This article presents the results achieved by 19 instruments belonging to 12 institutions from 7 different countries. The tested detectors are proportional counters, ionisation chambers, Geiger-Mueller and scintillators measuring dose rate in three stations with reference values from 110 to 1800 nGy h -1 All the results were given in terms of air kerma (nGy h -1 ) and the measurements show agreement within 25 % in all the sites. Evaluation criteria based on accuracy and statistical uncertainty were also carried out and 25 % of participants passed the test in all sites. (authors)

View of environmental radiation effects from the study of radiation biology in C. elegans

International Nuclear Information System (INIS)

Sakashita, Tetsuya

2011-01-01

Caenorhabditis (C.) elegans is a non-parasitic soil nematode and is well-known as a unique model organism, because of its complete cell-lineage, nervous network and genome sequences. Also, C. elegans can be easily manipulated in the laboratory. These advantages make C. elegans as a good in vivo model system in the field of radiation biology. Radiation effects in C. elegans have been studied for three decades. Here, I briefly review the current knowledge of the biological effects of ionizing irradiation in C. elegans with a scope of environmental radiation effects. Firstly, basic information of C. elegans as a model organism is described. Secondly, historical view is reported on the study of radiation biology in C. elegans. Thirdly, our research on learning behavior is presented. Finally, an opinion of the use of C. elegans for environmental radiation protection is referred. I believe that C. elegans may be a good promising in vivo model system in the field of environmental radiation biology. (author)

Haemopoietic cell renewal in radiation fields

Science.gov (United States)

Fliedner, T. M.; Nothdurft, W.; Tibken, B.; Hofer, E.; Weiss, M.; Kindler, H.

1994-10-01

Space flight activities are inevitably associated with a chronic exposure of astronauts to a complex mixture of ionising radiation. Although no acute radiation consequences are to be expected as a rule, the possibility of Solar Particle Events (SPE) associated with relatively high doses of radiation (1 or more Gray) cannot be excluded. It is the responsibility of physicians in charge of the health of astronauts to evaluate before, during and after space flight activities the functional status of haemopoietic cell renewal. Chronic low level exposure of dogs indicate that daily gamma-exposure doses below about 2 cGy are tolerated for several years as far as blood cell concentrations are concerned. However, the stem cell pool may be severely affected. The maintenance of sufficient blood cell counts is possible only through increased cell production to compensate for the radiation inflicted excess cell loss. This behaviour of haemopoietic cell renewal during chronic low level exposure can be simulated by bioengineering models of granulocytopoiesis. It is possible to define a ``turbulence region'' for cell loss rates, below which an prolonged adaptation to increased radiation fields can be expected to be tolerated. On the basis of these experimental results, it is recommended to develop new biological indicators to monitor haemopoietic cell renewal at the level of the stem cell pool using blood stem cells in addition to the determination of cytokine concentrations in the serum (and other novel approaches). To prepare for unexpected haemopoietic effects during prolonged space missions, research should be increased to modify the radiation sensitivity of haemopoietic stem cells (for instance by the application of certain regulatory molecules). In addition, a ``blood stem cell bank'' might be established for the autologous storage of stem cells and for use in space activities keeping them in a radiation protected container.

Near-field radiation between graphene-covered carbon nanotube arrays

Energy Technology Data Exchange (ETDEWEB)

Zhang, Richard Z.; Liu, Xianglei; Zhang, Zhuomin M., E-mail: zhuomin.zhang@me.gatech.edu [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2015-05-15

It has been shown that at small separation distances, thermal radiation between hyperbolic metamaterials is enhanced over blackbodies. This theoretical study considers near-field radiation when graphene is covered on the surfaces of two semi-infinite vertically aligned carbon nanotube (VACNT) arrays separated by a sub-micron vacuum gap. Doped graphene is found to improve photon tunneling in a broad hyperbolic frequency range, due to the interaction with graphene-graphene surface plasmon polaritons (SPP). In order to elucidate the SPP resonance between graphene on hyperbolic substrates, vacuum-suspended graphene sheets separated by similar gap distances are compared. Increasing the Fermi energy through doping shifts the spectral heat flux peak toward higher frequencies. Although the presence of graphene on VACNT does not offer huge near-field heat flux enhancement over uncovered VACNT, this study identifies conditions (i.e., gap distance and doping level) that best utilize graphene to augment near-field radiation. Through the investigation of spatial Poynting vectors, heavily doped graphene is found to increase penetration depths in hyperbolic modes and the result is sensitive to the frequency regime. This study may have an impact on designing carbon-based vacuum thermophotovoltaics and thermal switches.

The upper bound of abutment scour defined by selected laboratory and field data

Science.gov (United States)

Benedict, Stephen; Caldwell, Andral W.

2015-01-01

The U.S. Geological Survey, in cooperation with the South Carolina Department of Transportation, conducted a field investigation of abutment scour in South Carolina and used that data to develop envelope curves defining the upper bound of abutment scour. To expand upon this previous work, an additional cooperative investigation was initiated to combine the South Carolina data with abutment-scour data from other sources and evaluate the upper bound of abutment scour with the larger data set. To facilitate this analysis, a literature review was made to identify potential sources of published abutment-scour data, and selected data, consisting of 446 laboratory and 331 field measurements, were compiled for the analysis. These data encompassed a wide range of laboratory and field conditions and represent field data from 6 states within the United States. The data set was used to evaluate the South Carolina abutment-scour envelope curves. Additionally, the data were used to evaluate a dimensionless abutment-scour envelope curve developed by Melville (1992), highlighting the distinct difference in the upper bound for laboratory and field data. The envelope curves evaluated in this investigation provide simple but useful tools for assessing the potential maximum abutment-scour depth in the field setting.

Electromagnetic radiation from beam-plasma instabilities

Science.gov (United States)

Pritchett, P. L.; Dawson, J. M.

1983-01-01

A computer simulation is developed for the generation of electromagnetic radiation in an electron beam-plasma interaction. The plasma is treated as a two-dimensional finite system, and effects of a continuous nonrelativistic beam input are accounted for. Three momentum and three field components are included in the simulation, and an external magnetic field is excluded. EM radiation generation is possible through interaction among Langmuir oscillations, ion-acoustic waves, and the electromagnetic wave, producing radiation perpendicular to the beam. The radiation is located near the plasma frequency, and polarized with the E component parallel to the beam. The scattering of Langmuir waves caused by ion-acoustic fluctuations generates the radiation. Comparison with laboratory data for the three-wave interactions shows good agreement in terms of the radiation levels produced, which are small relative to the plasma thermal energy.

Field Deployable Gamma Radiation Detectors for DHS Use

Energy Technology Data Exchange (ETDEWEB)

Sanjoy Mukhopadhyay

2007-08-01

Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER{trademark}, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack{trademark} that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant

Field Deployable Gamma Radiation Detectors for DHS Use

International Nuclear Information System (INIS)

Sanjoy Mukhopadhyay

2007-01-01

Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER(trademark), which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack(trademark) that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant

OH megamasers: dense gas & the infrared radiation field

Science.gov (United States)

Huang, Yong; Zhang, JiangShui; Liu, Wei; Xu, Jie

2018-06-01

To investigate possible factors related to OH megamaser formation (OH MM, L_{H2O}>10L_{⊙}), we compiled a large HCN sample from all well-sampled HCN measurements so far in local galaxies and identified with the OH MM, OH kilomasers (L_{H2O}gas and the dense gas, respectively), we found that OH MM galaxies tend to have stronger HCN emission and no obvious difference on CO luminosity exists between OH MM and non-OH MM. This implies that OH MM formation should be related to the dense molecular gas, instead of the low-density molecular gas. It can be also supported by other facts: (1) OH MMs are confirmed to have higher mean molecular gas density and higher dense gas fraction (L_{HCN}/L_{CO}) than non-OH MMs. (2) After taking the distance effect into account, the apparent maser luminosity is still correlated with the HCN luminosity, while no significant correlation can be found at all between the maser luminosity and the CO luminosity. (3) The OH kMs tend to have lower values than those of OH MMs, including the dense gas luminosity and the dense gas fraction. (4) From analysis of known data of another dense gas tracer HCO^+, similar results can also be obtained. However, from our analysis, the infrared radiation field can not be ruled out for the OH MM trigger, which was proposed by previous works on one small sample (Darling in ApJ 669:L9, 2007). On the contrary, the infrared radiation field should play one more important role. The dense gas (good tracers of the star formation) and its surrounding dust are heated by the ultra-violet (UV) radiation generated by the star formation and the heating of the high-density gas raises the emission of the molecules. The infrared radiation field produced by the re-radiation of the heated dust in turn serves for the pumping of the OH MM.

IAEA programme in the field of radiation technology

International Nuclear Information System (INIS)

Chmielewski, Andrzej G.; Haji-Saeid, Mohammad

2005-01-01

Radiation technologies applying gamma sources and electron accelerators for material modification are well-established processes. There are over 160 gamma industrial irradiators and 1300 electron industrial accelerators in operation worldwide. A new advancement in the field of radiation sources engineering is the development of high power direct e - /X conversion sources based on electron accelerators. Technologies to be developed beside environmental applications could be nanomaterials, structure engineered materials (sorbents, composites, ordered polymers, etc.) and natural polymers' processing. New products based on radiation-processed polysaccharides have already been commercialised in many countries of the East Asia and Pacific Region, especially in those being rich in natural polymers. Very important and promising applications concern environmental protection-radiation technology, being a clean and environment friendly process, helps to curb pollutants' emission as well. Industrial plants for flue gas treatment have been constructed in Poland and China. The pilot plant in Bulgaria using this technology has just started its operation. The Polish plant is equipped with accelerators of over 1 MW power, a breakthrough in radiation technology application. The industrial plant for wastewater treatment is under development in Korea and a pilot plant for sewage sludge irradiation has been in operation in India for many years. Due to recent developments, the Agency has restructured its programme and organized a Technical Meeting (TM) on 'Emerging Applications of Radiation Technology for the 21st Century' at its Headquarters in Vienna, Austria, in April 2003, to review the present situation and possible developments of radiation technology to contribute to a sustainable development. This meeting provided the basic input to launch others in the most important fields of radiation technology applications: 'Advances in Radiation Chemistry of Polymers' (Notre Dame, USA

IAEA programme in the field of radiation technology

Science.gov (United States)

Chmielewski, Andrzej G.; Haji-Saeid, Mohammad

2005-07-01

Radiation technologies applying gamma sources and electron accelerators for material modification are well-established processes. There are over 160 gamma industrial irradiators and 1300 electron industrial accelerators in operation worldwide. A new advancement in the field of radiation sources engineering is the development of high power direct e-/X conversion sources based on electron accelerators. Technologies to be developed beside environmental applications could be nanomaterials, structure engineered materials (sorbents, composites, ordered polymers, etc.) and natural polymers' processing. New products based on radiation-processed polysaccharides have already been commercialised in many countries of the East Asia and Pacific Region, especially in those being rich in natural polymers. Very important and promising applications concern environmental protection-radiation technology, being a clean and environment friendly process, helps to curb pollutants' emission as well. Industrial plants for flue gas treatment have been constructed in Poland and China. The pilot plant in Bulgaria using this technology has just started its operation. The Polish plant is equipped with accelerators of over 1 MW power, a breakthrough in radiation technology application. The industrial plant for wastewater treatment is under development in Korea and a pilot plant for sewage sludge irradiation has been in operation in India for many years. Due to recent developments, the Agency has restructured its programme and organized a Technical Meeting (TM) on "Emerging Applications of Radiation Technology for the 21st Century" at its Headquarters in Vienna, Austria, in April 2003, to review the present situation and possible developments of radiation technology to contribute to a sustainable development. This meeting provided the basic input to launch others in the most important fields of radiation technology applications: "Advances in Radiation Chemistry of Polymers" (Notre Dame, USA

The Stanford Synchrotron Radiation Laboratory, 20 years of synchrotron light

International Nuclear Information System (INIS)

Cantwell, K.

1993-08-01

The Stanford Synchrotron Radiation Laboratory (SSRL) is now operating as a fully dedicated light source with low emittance electron optics, delivering high brightness photon beams to 25 experimental stations six to seven months per year. On October 1, 1993 SSRL became a Division of the Stanford Linear Accelerator Center, rather than an Independent Laboratory of Stanford University, so that high energy physics and synchrotron radiation now function under a single DOE contract. The SSRL division of SLAC has responsibility for operating, maintaining and improving the SPEAR accelerator complex, which includes the storage ring and a 3 GeV injector. SSRL has thirteen x-ray stations and twelve VUV/Soft x-ray stations serving its 600 users. Recently opened to users is a new spherical grating monochromator (SGM) and a multiundulator beam line. Circularly polarized capabilities are being exploited on a second SGM line. New YB 66 crystals installed in a vacuum double-crystal monochromator line have sparked new interest for Al and Mg edge studies. One of the most heavily subscribed stations is the rotation camera, which has been recently enhanced with a MAR imaging plate detector system for protein crystallography on a multipole wiggler. Under construction is a new wiggler-based structural molecular biology beam line with experimental stations for crystallography, small angle scattering and x-ray absorption spectroscopy. Plans for new developments include wiggler beam lines and associated facilities specialized for environmental research and materials processing

Micro Penning Trap for Continuous Magnetic Field Monitoring in High Radiation Environments

Science.gov (United States)

Latorre, Javiera; Bollen, Georg; Gulyuz, Kerim; Ringle, Ryan; Bado, Philippe; Dugan, Mark; Lebit Team; Translume Collaboration

2016-09-01

As new facilities for rare isotope beams, like FRIB at MSU, are constructed, there is a need for new instrumentation to monitor magnetic fields in beam magnets that can withstand the higher radiation level. Currently NMR probes, the instruments used extensively to monitor magnetic fields, do not have a long lifespans in radiation-high environments. Therefore, a radiation-hard replacement is needed. We propose to use Penning trap mass spectrometry techniques to make high precision magnetic field measurements. Our Penning microtrap will be radiation resistant as all of the vital electronics will be at a safe distance from the radiation. The trap itself is made from materials not subject to radiation damage. Penning trap mass spectrometers can determine the magnetic field by measuring the cyclotron frequency of an ion with a known mass and charge. This principle is used on the Low Energy Beam Ion Trap (LEBIT) minitrap at NSCL which is the foundation for the microtrap. We have partnered with Translume, who specialize in glass micro-fabrication, to develop a microtrap in fused-silica glass. A microtrap is finished and ready for testing at NSCL with all of the electronic and hardware components setup. DOE Phase II SBIR Award No. DE-SC0011313, NSF Award Number 1062410 REU in Physics, NSF under Grant No. PHY-1102511.

Turbulent amplification of magnetic fields in laboratory laser-produced shock waves

International Nuclear Information System (INIS)

Meinecke, J.; Doyle, H.W.; Bell, A.R.; Schekochihin, A.A.; Miniati, F.; Bingham, R.; Koenig, M.; Pelka, A.; Ravasio, A.; Yurchak, R.

2014-01-01

X-ray and radio observations of the supernova remnant Cassiopeia A reveal the presence of magnetic fields about 100 times stronger than those in the surrounding interstellar medium. Field coincident with the outer shock probably arises through a nonlinear feedback process involving cosmic rays. The origin of the large magnetic field in the interior of the remnant is less clear but it is presumably stretched and amplified by turbulent motions. Turbulence may be generated by hydrodynamic instability at the contact discontinuity between the supernova ejecta and the circumstellar gas. However, optical observations of Cassiopeia A indicate that the ejecta are interacting with a highly inhomogeneous, dense circumstellar cloud bank formed before the supernova explosion. Here we investigate the possibility that turbulent amplification is induced when the outer shock overtakes dense clumps in the ambient medium. We report laboratory experiments that indicate the magnetic field is amplified when the shock interacts with a plastic grid. We show that our experimental results can explain the observed synchrotron emission in the interior of the remnant. The experiment also provides a laboratory example of magnetic field amplification by turbulence in plasmas, a physical process thought to occur in many astrophysical phenomena. (authors)

Conditions's considerations of the CT radiation field

International Nuclear Information System (INIS)

Andrade, Lucio das Chagas de; Peixoto, Jose Guilherme Pereira

2013-01-01

In obtaining the standardization of radiation fields in diagnostic radiology were established standards and qualities to X radiation beams, which are specified in terms of the tension in the tube, first CSR, additional filters, homogeneity coefficient or second CSR. The qualities recommended in CT (RQT), are established in IEC 61267, which is the reference for the establishment of beams in diagnostic radiology. (author)

Quantum theory of laser radiation scattering by electrons in magnetic fields

International Nuclear Information System (INIS)

Rochlin, H.; Davidovich, L.

1982-01-01

A system consisting of an electron in a static magnetic field, interacting with the quantized electromagnetic field, within the non-relativistic and electric dipole approximations (with a cutoff in momentum space) is considered. The Heisenberg equations of motion are solved exactly and the time evolution of the electric field is determined. The power spectrum of the scattered radiation is calculated, when the electromagnetic field is initially in a coherent state. The results for the line shape of the scattered radiation are shown to be valid for magnetic fields up to 10 12 G. The quantization of the electromagnetic field allows one to consider effects of the natural linewidth and its dependence on the magnetic field. The renormalization of the electron mass is included in these treatment, and the results remain finite when the cutoff goes to infinity. (Author) [pt

Comparative investigation of three dose rate meters for their viability in pulsed radiation fields

International Nuclear Information System (INIS)

Gotz, M; Karsch, L; Pawelke, J

2015-01-01

Pulsed radiation fields, characterized by microsecond pulse duration and correspondingly high pulse dose rates, are increasingly used in therapeutic, diagnostic and research applications. Yet, dose rate meters which are used to monitor radiation protection areas or to inspect radiation shielding are mostly designed, characterized and tested for continuous fields and show severe deficiencies in highly pulsed fields. Despite general awareness of the problem, knowledge of the specific limitations of individual instruments is very limited, complicating reliable measurements. We present here the results of testing three commercial dose rate meters, the RamION ionization chamber, the LB 1236-H proportional counter and the 6150AD-b scintillation counter, for their response in pulsed radiation fields of varied pulse dose and duration. Of these three the RamION proved reliable, operating in a pulsed radiation field within its specifications, while the other two instruments were only able to measure very limited pulse doses and pulse dose rates reliably. (paper)

Test plan for preparing the Rapid Transuranic Monitoring Laboratory for field deployment

International Nuclear Information System (INIS)

McIsaac, C.V.; Sill, C.W.; Gehrke, R.J.; Killian, E.W.; Watts, K.D.

1994-04-01

This plan describes experimental work that will be performed during fiscal year 1994 to prepare the Rapid Transuranic Monitoring Laboratory (RTML) for routine field use by US Department of Energy (DOE) Environmental Restoration and Waste Management programs. The RTML is a mobile, field-deployable laboratory developed at the Idaho National Engineering Laboratory (INEL) that provides a rapid, cost-effective means of characterizing and monitoring radioactive waste remediation sites for low-level radioactive contaminants. Analytical instruments currently installed in the RTML include an extended-range, germanium photon analysis spectrometer with an automatic sample changer; two, large-area, ionization chamber alpha spectrometers; and four alpha continuous air monitors. The RTML was field tested at the INEL during June 1993 in conjunction with the Buried Waste Integrated Demonstration's remote retrieval demonstration. The major tasks described in this test plan are to (a) evaluate the beta detectors for use in screening soil samples for 90 Sr, (b) upgrade the alpha spectral analysis software programs, and (c) upgrade the photon spectral analysis software programs

Radiation and Homeostasis

International Nuclear Information System (INIS)

Sugahara, T.; Nikaido, O.; Niwa, O.

2002-01-01

These proceedings aim to promote the understanding of the health hazard of radiation at low dose range and to construct a more solid basis for radiation safety policy. Radiation hazard has been the central issue of investigation in the field of radiation research. The two major approaches are mechanistic analysis by laboratory investigation and phenomenological analysis of radiation-exposed population as represented by epidemiology. In an increasingly safety-conscious society, the extremely low level risk associated with low dose of radiation has become an important issue. In this area, the phenomenological approach has a limit. DNA damage is the primary and direct cause of the risk. Tremendous progress has been made recently in the basic understanding of radiation effects on cells and tissues and the importance of damage response rather than damage itself. This challenges the classical linear non-threshold hypothesis

Dynamics of Charged Particles and their Radiation Field

International Nuclear Information System (INIS)

Poisson, E

2006-01-01

an electron for very long times. Without radiation reaction, the motion of an electron in the trap is an epicycle that consists of a rapid (and small) cyclotron orbit superposed onto a slow (and large) magnetron orbit. Spohn shows that according to the Landau-Lifshitz equations, the radiation reaction produces a damping of the cyclotron motion. For reasonable laboratory situations this damping occurs over a time scale of the order of 0.1 second. This experiment might well be within technological reach. The presentation of the quantum theory is based on the nonrelativistic Abraham model, which upon quantization leads to the well-known Pauli-Fierz Hamiltonian of nonrelativistic quantum electrodynamics. This theory, an approximation to the fully relativistic version of QED, has a wide domain of validity that includes many aspects of quantum optics and laser-matter interactions. I first admit that I found Spohn's presentation to be tough going. Unlike the pair of delightful books by Cohen-Tannoudji, Dupont-Roc, and Grynberg, this is not a gentle introduction to the quantum theory of a charged particle coupled to its own electromagnetic field. Instead, Spohn proceeds rather quickly through the formulation of the theory (defining the Hamiltonian and the Hilbert space) and then presents some applications (for example, he constructs the ground states of the theory, he examines radiation processes, and he explores finite-temperature aspects). There is a lot of material in the eight chapters devoted to the quantum theory, but my insufficient preparation and the advanced nature of Spohn's presentation were significant obstacles. One of the most useful resources in Spohn's book are the historical notes and literature reviews that are inserted at the end of each chapter. I discovered a wealth of interesting articles by reading these, and I am grateful that the author made the effort to collect this information for the benefit of his readers. (book review)

Experimental study on the luminous radiation associated to the field emission of samples submitted to high RF fields

International Nuclear Information System (INIS)

Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Luong, M.; Tan, J.; Bonin, B.; Safa, H.

1996-01-01

The accelerating gradient of the RF cavities is limited by the strong field emission (FE) of electrons stemming from the metallic walls. Previous experiments evidenced luminous radiations associated with electron emission of cathodes subjected to intense DC electric field. These observations invoked the proposal of new theoretical models of the field emission phenomenon. This experimental study extends the previous DC works to the RF case. A special copper RF cavity has been developed equipped with an optical window and a removable sample. It has been designed for measuring both electron current and luminous radiation emitted by the sample, subjected to maximum RF electric field. The optical apparatus attached to the cavity permits to characterize the radiation in terms of intensity, glowing duration and spectral distribution. The results concerning different niobium or copper samples, whom top was either scratched or intentionally contaminated with metallic or dielectric particles are summarized. (author)

A radiation-electric-field combination principle for SO2-oxidation in Ar-mixtures

International Nuclear Information System (INIS)

Leonhardt, J.; Krueger, H.; Popp, P.; Boes, J.

1981-01-01

A simple model for a radiation-induced SO 2 -oxidation in Ar using SO 2 /O 2 /Ar-mixtures has been described by Leonhardt a.o. It is possible to improve the efficiency of the radiation-induced SO 2 -oxidation in such mixtures if the electrons produced by the ionizing radiation are accelerated by means of an electric field. The energy of the field-accelerated electrons must be high enough to form reactive SO 2 radicals but not high enough to ionize the gas mixture. Such an arrangement is described. The connection between the rate of SO 3 -formation and the electric field and the connection between SO 3 -formation and decreasing of the O 2 -concentration in the reaction chaimber were experimentally determined. Further the G-values attained by means of the radiation-electric-field combination are discussed. (author)

About Region 3's Laboratory and Field Services at EPA's Environmental Science Center

Science.gov (United States)

Mission & contact information for EPA Region 3's Laboratory and Field Services located at EPA's Environmental Science Center: the Office of Analytical Services and Quality Assurance & Field Inspection Program

The radiation protection of workers. I.R.S.N.activities in 2005 in the field of radiation protection management

International Nuclear Information System (INIS)

Rannou, A.; Ameon, R.; Boisson, P.; Clairand, I.; Couasnon, O.; Franck, D.; Scanff, P.; Rehel, J.L.; Thevenet, M.

2005-01-01

This report presents the main work carried out by the Institute of radiation protection and nuclear safety (I.R.S.N.) in the year 2005 for the management of occupational radiological protection. it draws up an assessment for this same year of the occupational external exposures to ionizing radiation in France on the basis of passive dosimetry data transmitted to the I.R.S.N. by the approved dosimetry laboratories. (authors)

An historical overview of the activities in the field of exposure and risk assessment of non-ionizing radiation in Bulgaria.

Science.gov (United States)

Israel, Michel

2015-09-01

The exposure and risk evaluation process in Bulgaria concerning non-ionizing radiation health and safety started in the early 1970s. Then, the first research laboratory "Electromagnetic fields in the working environment" was founded in the framework of the Centre of Hygiene, belonging to the Medical Academy, Sofia. The main activities were connected with developing legislation, new equipment for measurement of electromagnetic fields, new methods for measurement and exposure assessment, in vivo and human studies for developing methods, studying the effect of non-ionizing radiation on human body, developing exposure limits. Most of the occupations as metal industry, plastic welding, energetics, physiotherapy, broadcasting, telephone stations, computer industry, etc., have been covered by epidemiological investigations and risk evaluation. In 1986, the ANSI standard for safe use of lasers has been implemented as national legislation that gave the start for studies in the field of risk assessment concerning the use of lasers in industry and medicine. The environmental exposure studies started in 1991 following the very fast implementation of the telecommunication technologies. Now, funds for research are very insignificant, and studies in the field of risk assessment are very few. Nevertheless, Bulgaria has been an active member of the WHO International EMF Project, since 1997, and that gives good opportunity for collaboration with other Member states, and for implementation of new approach in the EMF policy for workers and people's protection against non-ionizing radiation exposure.

Annual report of Radiation Laboratory Department of Nuclear Engineering Kyoto University for fiscal 1993

International Nuclear Information System (INIS)

1994-07-01

This publication is the collection of the papers presented research activities of Radiation Laboratory, Department of Nuclear Engineering, Kyoto University during the 1993 academic/fiscal year (April, 1993 - March, 1994). The 47 of the presented papers are indexed individually. (J.P.N.)

Annual report of Radiation Laboratory Department of Nuclear Engineering Faculty of Engineering, Kyoto University

International Nuclear Information System (INIS)

1993-07-01

This publication is the collection of the papers presented research activities of Radiation laboratory, Department of Nuclear Engineering, Kyoto University during the 1992 academic/fiscal year (April, 1992 - March, 1993). The 48 of the presented papers are indexed individually. (J.P.N.)

The exact electromagnetic field description of photon emission, absorption, and radiation pattern. II.

Science.gov (United States)

Grimes, Dale M; Grimes, Craig A

2002-10-01

This is the second of two articles, the first of which contains a proposed explanation of quantum theory based upon electron nonlocality and classical electrodynamics. In this second article classical field theory is used to describe a unique field set for exchange of radiation between an atomic eigenstate and the far field. The radiation satisfies the thermodynamic condition of reversibility as described by Boltzmann, Planck, and Einstein. The exchanged radiation supports the kinematic properties of photons, and it can be emitted or absorbed by a vanishingly small volume.

Comparing sensitivity of ecotoxicological effect endpoints between laboratory and field

DEFF Research Database (Denmark)

Selck, H.; Riemann, B.; Christoffersen, K.

2002-01-01

multispecies field tests using tributyltin (TBT) and linear alkylbenzene sulfonates (LAS) were compared with published laboratory single-species test results and measured in situ concentrations. Extrapolation methods were evaluated by comparing predicted no-effect concentrations (PNECs), calculated by AF...

International cooperation in the field of radiation application

International Nuclear Information System (INIS)

Sato, Shoichi

1993-01-01

Bilateral and multilateral research cooperations have been implemented at TRCRE, JAERI, producing favourable results in the field of radiation application. Frameworks and some achievements are described and the significance of the international cooperation is discussed. (Author)

Note on the preliminar proposal of the feasibility study for the implantation of a national laboratory of synchrotron radiation

International Nuclear Information System (INIS)

Lobo, R.; Muniz, R.P.A.

1983-01-01

Some socio-economic and political aspects on the implantation of a National Laboratory of Synchrotron Radiation in Brazil are discussed. Some applications of such a radiation, including technological ones, are presented. (L.C.) [pt

On-site laboratory support of Oak Ridge National Laboratory environmental restoration field activities

International Nuclear Information System (INIS)

Burn, J.L.E.

1995-07-01

A remedial investigation/feasibility study has been undertaken at Oak Ridge National Laboratory (ORNL). Bechtel National, Inc. and partners CH2M Hill, Ogden Environmental and Energy Services, and PEER Consultants are contracted to Lockheed Martin Energy Systems, performing this work for ORNL's Environmental Restoration (ER) Program. An on-site Close Support Laboratory (CSL) established at the ER Field Operations Facility has evolved into a laboratory where quality analytical screening results can be provided rapidly (e.g., within 24 hours of sampling). CSL capabilities include three basic areas: radiochemistry, chromatography, and wet chemistry. Radiochemical analyses include gamma spectroscopy, tritium and carbon-14 screens using liquid scintillation analysis, and gross alpha and beta counting. Cerenkov counting and crown-ether-based separation are the two rapid methods used for radiostrontium determination in water samples. By extending count times where appropriate, method detection limits can match those achieved by off-site contract laboratories. Volatile organic compounds are detected by means of gas chromatography using either headspace or purge and trap sample introduction (based on EPA 601/602). Ionic content of water samples is determined using ion chromatography and alkalinity measurement. Ion chromatography is used to quantify both anions (based on EPA 300) and cations. Wet chemistry procedures performed at the CSL include alkalinity, pH (water and soil), soil resistivity, and dissolved/suspended solids. Besides environmental samples, the CSL routinely screens health and safety and waste management samples. The cost savings of the CSL are both direct and indirect

Radiation reaction force and unification of electromagnetic and gravitational fields

International Nuclear Information System (INIS)

Lo, C.Y.; Goldstein, G.R.; Napier, A.

1981-04-01

A unified theory of electromagnetic and gravitational fields should modify classical electrodynamics such that the radiation reaction force is accounted for. The analysis leads to a five-dimensional unified theory of five variables. The theory is supported by showing that, for the case of a charged particle moving in a constant magnetic field, the radiation reaction force is indeed included. Moreover, this example shows explicitly that physical changes are associated with the fifth variable. Thus, the notion of a physical five-dimensional space should be seriously taken into consideration

Potential for improved radiation thermometry measurement uncertainty through implementing a primary scale in an industrial laboratory

Science.gov (United States)

Willmott, Jon R.; Lowe, David; Broughton, Mick; White, Ben S.; Machin, Graham

2016-09-01

A primary temperature scale requires realising a unit in terms of its definition. For high temperature radiation thermometry in terms of the International Temperature Scale of 1990 this means extrapolating from the signal measured at the freezing temperature of gold, silver or copper using Planck’s radiation law. The difficulty in doing this means that primary scales above 1000 °C require specialist equipment and careful characterisation in order to achieve the extrapolation with sufficient accuracy. As such, maintenance of the scale at high temperatures is usually only practicable for National Metrology Institutes, and calibration laboratories have to rely on a scale calibrated against transfer standards. At lower temperatures it is practicable for an industrial calibration laboratory to have its own primary temperature scale, which reduces the number of steps between the primary scale and end user. Proposed changes to the SI that will introduce internationally accepted high temperature reference standards might make it practicable to have a primary high temperature scale in a calibration laboratory. In this study such a scale was established by calibrating radiation thermometers directly to high temperature reference standards. The possible reduction in uncertainty to an end user as a result of the reduced calibration chain was evaluated.

Fate of Listeria spp. on parsley leaves grown in laboratory and field cultures.

Science.gov (United States)

Dreux, N; Albagnac, C; Carlin, F; Morris, C E; Nguyen-The, C

2007-11-01

To investigate the population dynamics of Listeria monocytogenes and Listeria innocua on the aerial surfaces of parsley. Under 100% relative humidity (RH) in laboratory and regardless of the inoculum tested (10(3)-10(8) CFU per leaf), counts of L. monocytogenes EGDe, LO28, LmP60 and L. innocua CIP 80-12 tended towards approx. 10(5) CFU per leaf. Under low RH, Listeria spp. populations declined regardless to the inoculum size (10(4)-10(8) CFU per leaf). L. innocua CIP 80-12 survived slightly better than L. monocytogenes in the laboratory and was used in field cultures. Under field cultures, counts of L. innocua decreased more rapidly than in the laboratory, representing a decrease of 9 log(10) in 2 days in field conditions compared to a decrease of 4.5 log(10) in 8 days in the laboratory. Counts of L. innocua on tunnel parsley cultures were always higher (at least by 100 times) than those on unprotected parsley culture. Even with a high inoculum and under protected conditions (i.e. plastic tunnels), population of L. monocytogenes on the surface of parsley on the field would decrease by several log(10) scales within 2 days. Direct contamination of aerial surfaces of parsley with L. monocytogenes (i.e. through contaminated irrigation water) will not lead to contaminated produce unless it occurs very shortly before harvest.

A multigroup treatment of radiation transport

International Nuclear Information System (INIS)

Tahir, N.A.; Laing, E.W.; Nicholas, D.J.

1980-12-01

A multi-group radiation package is outlined which will accurately handle radiation transfer problems in laser-produced plasmas. Bremsstrahlung, recombination and line radiation are included as well as fast electron Bremsstrahlung radiation. The entire radiation field is divided into a large number of groups (typically 20), which diffuse radiation energy in real space as well as in energy space, the latter occurring via electron-radiation interaction. Using this model a radiation transport code will be developed to be incorporated into MEDUSA. This modified version of MEDUSA will be used to study radiative preheat effects in laser-compression experiments at the Central Laser Facility, Rutherford Laboratory. The model is also relevant to heavy ion fusion studies. (author)

Zinc injection helps reduce radiation field buildup in BWRs

International Nuclear Information System (INIS)

Wood, C.

1991-01-01

The injection of zinc into the reactor water of BWRs (Boiling Water Reactors) was a technique developed by General Electric (GE) and the Electric Power Research Institute (EPRI) to control the buildup of radiation fields from cobalt-60 on out-of-core piping. The presence of 5-10ppb zinc in the reactor water reduces the growth of oxide films on stainless steel surfaces, thereby reducing the number of sites available for the incorporation of cobalt; zinc also competes with cobalt for the sites. In September 1990, EPRI organized a workshop at the request of several US utilities to provide a forum to discuss experiences with zinc injection. The meeting focused on six main issues: the effect of zinc on radiation fields in normal water chemistry; the radiation buildup in hydrogen water chemistry, with and without zinc; the effects of zinc-65; the corrosion of fuel cladding and structural materials; the performance of zinc injection and monitoring equipment; and planning for zinc injection. (author)

Study of extremely low frequency electromagnetic field (ELF EMF) radiation produced by consumer products

International Nuclear Information System (INIS)

Roha Tukimin; Ahmad Fazli Ahmad Sanusi; Rozaimah Abd Rahim; Mohd Yusof Mohd Ali; Mohamad Amirul Nizam Mohamad Thari

2006-01-01

Extremely low frequency electromagnetic field ( ELF EMF) radiation falls under category of non-ionising radiation (NIR).ELF EMF consists of electric and magnetic fields. Excessive exposure to ELF EMF radiation may cause biological and health effects to human beings such as behavioral changes, stochastic and as initiator of cancer. In daily life, the main source of extremely low frequency electromagnetic radiation are consumer products in our home and office. Due to its ability to cause hazard, a study of ELF EMF radiation produced by consumer product was conducted. For this preliminary study, sample of 20 types electrical appliances were selected. The measurement was covered electric and magnetic field strength produced by the sample. PMM model EHP50A were used for measurement and data analysis. The results were compared with the permissible limits recommended by International Commission of Non-Ionising Radiation Protection (ICNIRP) for members of public (1000 mGauss and 5000 V/m). The results showed that all tested sample produced magnetic and electric field but still under the permissible limit recommended by ICNIRP. Besides that we found that field strengths can be very high at closer distance to the sample. (Author)

ITRAP: state-of-the-art of radiation detectors techniques for field application

International Nuclear Information System (INIS)

Beck, P.

2002-01-01

Full text: The paper describes the results of the pilot study ITRAP (Illicit Trafficking Radiation Assessment Program) of commercially available monitoring systems for the detection of nuclear and other radioactive materials and developments which where triggered during this study. ITRAP was carried out from ARC Seibersdorf Research (ARCS) on a contract by the Austrian Government, coordinated by the Ministry of Economic Affairs and Labor. In co-operation with the International Atomic Energy Agency (IAEA) the program was also supported by the Word Customs Organization (WCO), the International Criminal Police Organization (INTERPOL) and the Hungarian Government. The ITRAP study consists of a laboratory test phase and field tests at the Austrian/Hungarian border Nickelsdorf and the Vienna airport, each for a duration of one year. ITRAP describes fix-installed instruments as well as mobile hand held instruments for the detection of nuclear and radioactive material in the field. ITRAP defined and tested minimum requirements which leads to the basics for IEC- and ISO- standards. The results of ITRAP will be used to derive realistic performance requirements for detection of nuclear and radioactive control systems in view of optimized technical and economic conditions. (author)

Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats☆

Science.gov (United States)

Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

2012-01-01

In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR) than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested. PMID:25685416

Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats

Directory of Open Access Journals (Sweden)

Haitham S. Mohammed

2013-03-01

Full Text Available In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day. EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS and rapid eye movement sleep (REM sleep revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested.

Laboratory- and Field-Based Assessment of Maximal Aerobic Power of Elite Stand-Up Paddle-Board Athletes.

Science.gov (United States)

Schram, Ben; Hing, Wayne; Climstein, Mike

2016-01-01

Stand-up paddle boarding (SUP) is a rapidly growing sport and recreational activity for which only anecdotal evidence exists on its proposed health, fitness, and injury-rehabilitation benefits. 10 internationally and nationally ranked elite SUP athletes. Participants were assessed for their maximal aerobic power on an ergometer in a laboratory and compared with other water-based athletes. Field-based assessments were subsequently performed using a portable gas-analysis system, and a correlation between the 2 measures was performed. Maximal aerobic power (relative) was significantly higher (P = .037) when measured in the field with a portable gas-analysis system (45.48 ± 6.96 mL · kg(-1) · min(-1)) than with laboratory-based metabolic-cart measurements (43.20 ± 6.67 mL · kg(-1) · min(-1)). There was a strong, positive correlation (r = .907) between laboratory and field maximal aerobic power results. Significantly higher (P = .000) measures of SUP paddling speed were found in the field than with the laboratory ergometer (+42.39%). There were no significant differences in maximal heart rate between the laboratory and field settings (P = .576). The results demonstrate the maximal aerobic power representative of internationally and nationally ranked SUP athletes and show that SUP athletes can be assessed for maximal aerobic power in the laboratory with high correlation to field-based measures. The field-based portable gas-analysis unit has a tendency to consistently measure higher oxygen consumption. Elite SUP athletes display aerobic power outputs similar to those of other upper-limb-dominant elite water-based athletes (surfing, dragon-boat racing, and canoeing).

Dose profile modeling of Idaho National Laboratory's active neutron interrogation laboratory

Energy Technology Data Exchange (ETDEWEB)

Chichester, D.L. [Idaho National Laboratory, 2525 N. Fremont Avenue, Idaho Falls, ID 83415 (United States)], E-mail: david.chichester@inl.gov; Seabury, E.H.; Zabriskie, J.M.; Wharton, J.; Caffrey, A.J. [Idaho National Laboratory, 2525 N. Fremont Avenue, Idaho Falls, ID 83415 (United States)

2009-06-15

A new laboratory has been commissioned at Idaho National Laboratory for performing active neutron interrogation research and development. The facility is designed to provide radiation shielding for deuterium-tritium (DT) fusion (14.1 MeV) neutron generators (2x10{sup 8} n/s), deuterium-deuterium (DD) fusion (2.5 MeV) neutron generators (1x10{sup 7} n/s), and {sup 252}Cf spontaneous fission neutron sources (6.96x10{sup 7} n/s, 30 {mu}g). Shielding at the laboratory is comprised of modular concrete shield blocks 0.76 m thick with tongue-in-groove features to prevent radiation streaming, arranged into one small and one large test vault. The larger vault is designed to allow operation of the DT generator and has walls 3.8 m tall, an entrance maze, and a fully integrated electrical interlock system; the smaller test vault is designed for {sup 252}Cf and DD neutron sources and has walls 1.9 m tall and a simple entrance maze. Both analytical calculations and numerical simulations were used in the design process for the building to assess the performance of the shielding walls and to ensure external dose rates are within required facility limits. Dose rate contour plots have been generated for the facility to visualize the effectiveness of the shield walls and entrance mazes and to illustrate the spatial profile of the radiation dose field above the facility and the effects of skyshine around the vaults.

Tomography of binomial states of the radiation field

NARCIS (Netherlands)

Bazrafkan, MR; Man'ko, [No Value

2004-01-01

The symplectic, optical, and photon-number tomographic symbols of binomial states of the radiation field are studied. Explicit relations for all tomograms of the binomial states are obtained. Two measures for nonclassical properties of these states are discussed.

Labor security in radiation flaw detection

International Nuclear Information System (INIS)

Margulis, U.Ya.; Chistov, E.D.; Partolin, O.F.; Pertsov, V.A.; Momzhiev, B.N.; Sprygaev, I.F.

1986-01-01

Problems of ensuring safe labour conditions in radiation flaw detection are considered. Methods for ionizing radiation protection are given calculating techniques for shielding flaw detectors and stationary structures are presented as well. Safe methods of nondestructive testing of items under field conditions, in a shop and special laboratories using gamma- and X-ray flaw detectors, betatrons, electron accelerators are described. Attention is paid to the principles of radiation factor stantardization as well as radiation monitoring. Analysis of accidents and recommendations on their prevention and liquidation of accidental consequences are given

Experimental study on the luminous radiation associated to the field emission of samples submitted to high RF fields

International Nuclear Information System (INIS)

Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Luong, M.; Tan, J.; Bonin, B.; Safa, H.

1996-01-01

Nowadays the accelerating gradient of the RF cavities is limited by the strong field emission (FE) of electrons stemming from the metallic walls. Previous experiments evidenced luminous radiations associated with electron emission on cathodes subjected to intense DC electric field. These observations led these authors to propose new theoretical models of the field emission phenomenon. The presented experimental study extends these previous DC works to the RF case. A special copper RF cavity has been developed equipped with an optical window and a removable sample. It has been designed for measuring both electron current and luminous radiation emitted by the sample, subjected to maximum RF electric field. The optical apparatus attached to the cavity permits to characterize the radiation in terms of intensity, glowing duration and spectral distribution. The results concerning different niobium or copper samples, whom top was either scratched or intentionally contaminated with metallic or dielectric particles are summarized. (author)

Field distribution on an HVDC wall bushing during laboratory rain tests

International Nuclear Information System (INIS)

Lampe, W.; Wikstrom, D.; Jacobson, B.

1991-01-01

This paper reports that an efficient counter-measure to suppress flashovers across HVDC wall bushings is to make their surfaces hydrophobic. This laboratory investigation reports the measured electric field along such a bushing under different environmental conditions. A significantly reduced radial field strength has been found for the hydrophobic bushing. Moreover, the total field strength distribution becomes almost independent of the prevailing dry zone. The flashover voltage for bushings with a hydrophobic surface is therefore significantly increased

Development of Remote Control Laboratory for Radiation Detection via Internet

International Nuclear Information System (INIS)

Park, Sang Tae; Lee, Hee Bok; Yuk, Keun Chul

2002-01-01

The role of experiments in science education is essential for understanding the natural phenomena and principle related to a subject. Therefore, the remote control experiment via Internet is one of key solution for distance learners in science education. The remote experiments are also necessary for the time-consuming experiment which takes several days, collaborative experiment between distance learners, expensive laboratory equipment which is not usually available to students, experimental procedure which is dangerous, etc. In this study, we have developed a general method for a remote control laboratory system using internet and interface techniques. It is possible for students to learn the nuclear physics to control the real instruments and conduct physics experimentation with internet techniques. We proposed the remote control radiation measurement system as a sample application. This system could be useful for the monitoring near a nuclear power plants in order to improve the environment data credibility to the public

Investigation of Radiation Fields at Aircraft Altitudes (invited paper)

International Nuclear Information System (INIS)

O'Sullivan, D.; Bartlett, D.; Grillmaier, R.; Heinrich, W.; Lindborg, L.; Schraube, H.; Silari, M.; Tommasino, L.; Zhou, D.

2000-01-01

Cosmic rays are believed to originate from several possible sources and recent research suggests that the bulk originate from the gas and dust of the interstellar medium and are accelerated by strong shock waves driven by supernova explosions. Cosmic ray particles are made up of γ98.5% hydrogen and helium and only 1.5% have charges greater than 2. Their average energy is about 1 GeV/nucleon and they lose energy through ionisation interactions and nuclear interactions with atoms of air as they penetrate deeply into the Earth's atmosphere. A very complicated radiation field develops as particles are generated by successive interaction of primary and secondary nuclei and a cascade of hadrons is produced in the atmosphere. The intensity of particles reaches a maximum at about 20 km above sea level (γ60 g.cm -2 ). The relative abundances of different particles change with depth within the atmosphere and mainly muons which are the decay products of charged mesons, reach sea level because of their weak interaction. The radiation field produced and consequently its effect on aircrew and frequent travellers is a matter of some concern. This paper outlines the results of investigations carried out to determine the characteristics of this radiation field and assess its impact on aircrew. (author)

Analysis of radiation fields in tomography on diffusion gaseous sound

International Nuclear Information System (INIS)

Bekman, I.N.

1999-01-01

Perspectives of application of equilibrium and stationary variants of diffusion tomography with radioactive gaseous sounds for spatial reconstruction of heterogeneous media in materials technology were considered. The basic attention were allocated to creation of simple algorithms of detection of sound accumulation on the background of monotonically varying concentration field. Algorithms of transformation of two-dimensional radiation field in three-dimensional distribution of radiation sources were suggested. The methods of analytical elongation of concentration field permitting separation of regional anomalies on the background of local ones and vice verse were discussed. It was shown that both equilibrium and stationary variants of diffusion tomography detect the heterogeneity of testing material, provide reduction of spatial distribution of elements of its structure and give an estimation of relative degree of defectiveness

A concept for NASA's Mars 2016 astrobiology field laboratory.

Science.gov (United States)

Beegle, Luther W; Wilson, Michael G; Abilleira, Fernando; Jordan, James F; Wilson, Gregory R

2007-08-01

The Mars Program Plan includes an integrated and coordinated set of future candidate missions and investigations that meet fundamental science objectives of NASA and the Mars Exploration Program (MEP). At the time this paper was written, these possible future missions are planned in a manner consistent with a projected budget profile for the Mars Program in the next decade (2007-2016). As with all future missions, the funding profile depends on a number of factors that include the exact cost of each mission as well as potential changes to the overall NASA budget. In the current version of the Mars Program Plan, the Astrobiology Field Laboratory (AFL) exists as a candidate project to determine whether there were (or are) habitable zones and life, and how the development of these zones may be related to the overall evolution of the planet. The AFL concept is a surface exploration mission equipped with a major in situ laboratory capable of making significant advancements toward the Mars Program's life-related scientific goals and the overarching Vision for Space Exploration. We have developed several concepts for the AFL that fit within known budget and engineering constraints projected for the 2016 and 2018 Mars mission launch opportunities. The AFL mission architecture proposed here assumes maximum heritage from the 2009 Mars Science Laboratory (MSL). Candidate payload elements for this concept were identified from a set of recommendations put forth by the Astrobiology Field Laboratory Science Steering Group (AFL SSG) in 2004, for the express purpose of identifying overall rover mass and power requirements for such a mission. The conceptual payload includes a Precision Sample Handling and Processing System that would replace and augment the functionality and capabilities provided by the Sample Acquisition Sample Processing and Handling system that is currently part of the 2009 MSL platform.

Annual report of the Osaka Laboratory for Radiation Chemistry, Japan Atomic Energy Research Institute, No. 29. April 1, 1995 - March 31, 1996

International Nuclear Information System (INIS)

1997-03-01

The annual research activities of the Osaka Laboratory for Radiation Chemistry, JAERI, during the fiscal year 1995, are reported. The research activities were conducted under two research programs: the study on laser-induced organic chemical reactions and the study on basic radiation technology for functional materials. Detailed description of the activities are presented as reviews on the following subjects: laser-induced chemical transformation, laser-induced reaction of polymer surface, photochemical separation of stable isotopes, microprocessing by radiation-induced polymerization, preparation of fine metal particles by gamma-ray irradiation, and electron beam dosimetry. The operation report of the irradiation facility is also included. In October 1995, the Osaka Laboratory was dissolved into the Kansai Research Establishment which was newly inaugurated to promote advanced photon research. Therefore, this is the final issue of the annual report of the Osaka Laboratory for Radiation Chemistry. (author)

Effects of chlorpyrifos on individuals and populations of Daphnia pulex in the laboratory and field

NARCIS (Netherlands)

Hoeven, N. van der; Gerritsen, A.A.M.

1997-01-01

Effects of the insecticide chlorpyrifos (cpf) on young (laboratory. Populations of D. pulex exposed to cpf were studied in the laboratory and field. In the field, cpf was applied in

Reduction in life span on normal human fibroblasts exposed to low-dose radiation in heavy-ion radiation field

International Nuclear Information System (INIS)

Suzuki, Masao; Yamaguchi, Chizuru; Yasuda, Hiroshi; Uchihori, Yukio; Fujitaka, Kazunobu

2003-01-01

We studied the effect of in vitro life span in normal human fibroblasts exposed to chronically low-dose radiation in heavy-ion radiation field. Cells were cultured in a CO 2 incubator, which was set in the irradiation room for biological study of heavy ions in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences (NIRS), and exposed to scattered radiations produced with heavy-ion beams throughout the life span of the cell population. Absorbed dose, which was measured using a thermoluminescence dosimeter(TLD) and a Si-semiconductor detector, was to be 1.4 mGy per day when operating the HIMAC machine for biological experiments. The total population doubling number of the exposed cells reduced to 79-93% of non-exposed control cells in the three independent experiments. There is evidence that the exposure of chronically low-dose radiation in heavy-ion radiation field promotes the life-span reduction in cellular level. (author)

Determination of dose rates in beta radiation fields using extrapolation chamber and GM counter

International Nuclear Information System (INIS)

Borg, J.; Christensen, P.

1995-01-01

The extrapolation chamber measurement method is the basic method for the determination of dose rates in beta radiation fields and the method has been used for the establishment of beta calibration fields. The paper describes important details of the method and presents results from the measurements of depth-dose profiles from different beta radiation fields with E max values down to 156 keV. Results are also presented from studies of GM counters for use as survey instruments for monitoring beta dose rates at the workplace. Advantages of GM counters are a simple measurement technique and high sensitivity. GM responses were measured from exposures in different beta radiation fields using different filters in front of the GM detector and the paper discusses the possibility of using the results from GM measurements with two different filters in an unknown beta radiation field to obtain a value of the dose rate. (Author)

Exercise for laboratory comparison of calibration coefficient in 137Cs beam, radiation protection - 2013/2014

International Nuclear Information System (INIS)

Cabral, T.S.; Potiens, M.P.A.; Soares, C.M.A.; Silveira, R.R.; Khoury, H.; Borges, J.C.

2015-01-01

This work deals with the preliminary results of the second exercise of comparing the radiation monitors calibration laboratories in Brazil. The exercise involved eight laboratories and the measured quantity is the air kerma in a beam of 137 Cs for radioprotection. The exercise was conducted by the LNMRI/IRD, in a star shaped arrangement from October 2013 to July 2015. The largest deviation was 2% of the calibration coefficient that is acceptable for applications in radioprotection. (author)

The influence of electromagnetic interference and ionizing radiation on cardiac pacemakers

International Nuclear Information System (INIS)

Salmi, J.; Malmivuo, J.A.V.

1990-01-01

Adverse effects of the ionizing and non-ionizing electromagnetic fields on five pacemaker models have been tested. The study consisted of three parts: 1. measurement of magnetic fields in a radiotherapy room (microtron MM14), 2. the application of non-ionizing electromagnetic fields on pacemakers in a test laboratory (1 ... 1000 μT, 10 ... 10 000 Hz), and 3. the application of ionizing radiation of different types of radiotherapy devices on the pacemakers. The magnetic field strength in the microtron treatment room was found to be under 7.5 μT, which is one order of magnitude lower than the tolerance level obtained for the pacemakers in the test laboratory. All the tested pacemakers tolerated the ionizing radiation dose levels (less than 60 Gy) which are used in the radiotherapy. (orig.) [de

Design and implementation of a virtual laboratory of radiation measurement; Diseno e implementacion de un laboratorio virtual de medicion de radiaciones

Energy Technology Data Exchange (ETDEWEB)

Alvarez T, J. R.; Morales S, J. B. [Facultad de Ingenieria, UNAM, Ciudad Universitaria, 04510 Mexico, D. F. (Mexico)], e-mail: jms0620@yahoo.com.mx

2009-10-15

The work involves the implementation of a virtual laboratory, this project is conducted in the Faculty of Engineering of National Autonomous University of Mexico with the name of LANUVI. It is intended that the laboratory can be used by students who have interest in the nuclear radiation knowledge as well as in its detection and attenuation, in addition serve as and introduction to nuclear systems. In the first part of project will conduct a source that can simulate the particle radiation of Alfa, beta, neutrons and gamma rays. The project will take sources used in class laboratories and elements that are dangerous but are used in different practical applications. After taking the source analyzing the particles behaviour in different media like air, animal tissue, aluminium, lead, etc. The analysis is done in different ways in order to know with which material can stop or mitigate the different types of radiation. Finally shall be measure radioactivity with different types of detectors. At this point, has the behaviour of ionization chamber but in the future is expected to make the simulation of some other radiation detectors. The mathematical models we represent the behaviour of these cases were implemented in free software. The program will be used to implement the virtual laboratory with radiation sources, detectors and different types of shields will be Blender which is a free software that is used by many users for the embodiment of games but try to use as a tool to help visualize the different equipment that is widely used in a radioactive materials laboratory. (Author)

Preliminary analysis of radiologic consequence in accident cases with radiation sources in laboratories of the Physics Department of the IEN, cyclotrons and laboratories annexed

International Nuclear Information System (INIS)

Fajardo, P.W.; Silva, J.J.G. da.

1987-03-01

The requirements necessaries to the elaboration of the situation of Emergency PLans of the Nuclear Engineering Institute (IEN), Brazil, in particular, cases of radiation emergency are presented. An estimate of radiation in the laboratories of the Physic Department of the IEN, in case of accident, are given. The results presented are based in some hypothesis, values of radionuclide activity furnished by Radioisotopes Division and values of activities estimated by Radiation Protection Section of the IEN in function of datas achieved with cyclotron Division. The dose calculations are done to the cases of radionuclides inhalation and immersion of person in a semi-infinite cloud of contaminants. (V.R.B.)

New three-dimensional moving field radiation therapy for brain tumors

Energy Technology Data Exchange (ETDEWEB)

Mitsuyama, Fuyuki; Kanno, Tetsuo; Nagata, Yutaka; Koga, Sukehiko [Fujita-Gakuen Health Univ., Toyoake, Aichi (Japan); Jain, V K

1992-06-01

A new modified rotation radiation method called 'three-dimensional moving field radiation therapy' is described. The new method uses rotation in many planes while maintaining the same isocenter to achieve a good spatial dose distribution. This delivers a high dose to tumors and spares the surrounding normal structures. This easy method can be carried out using the equipment for conventional rotation radiation therapy. The new method was superior to the one plane rotation radiation therapy using a physical phantom with film, a chemical phantom using the iodine-starch reaction, and a new biological model using tumor cells. Treatment of six brain tumors irradiated with total air doses of 50-60 Gy caused no hair loss or radiation necrosis. (author).

Between and within laboratory reliability of mouse behaviour recorded in home-cage and open-field.

Science.gov (United States)

Robinson, Lianne; Spruijt, Berry; Riedel, Gernot

2018-04-15

Reproducibility of behavioural findings between laboratories is difficult due to behaviour being sensitive to environmental factors and interactions with genetics. The objective of this study was to investigate reproducibility of behavioural data between laboratories using the PhenoTyper home cage observation system and within laboratory reproducibility using different lighting regimes. The ambulatory activity of C57BL/6 and DBA/2 mice was tested in PhenoTypers in two laboratories under near identical housing and testing conditions (Exp. 1). Additionally activity and anxiety were also assessed in the open-field test. Furthermore, testing in either a normal or inverted light/dark cycle was used to determine effects of lighting regime in a within-laboratory comparison in Aberdeen (Exp. 2). Using the PhenoTyper similar circadian rhythms were observed across laboratories. Higher levels of baseline and novelty-induced activity were evident in Aberdeen compared to Utrecht although strain differences were consistent between laboratories. Open field activity was also similar across laboratories whereas strain differences in anxiety were different. Within laboratory analysis of different lighting regimes revealed that behaviour of the mice was sensitive to changes in lighting. Utilisation of a home cage observation system facilitates the reproducibility of activity but not anxiety-related behaviours across laboratories by eliminating environmental factors known to influence reproducibility in standard behavioural tests. Standardisation of housing/test conditions resulted in reproducibility of home cage and open field activity but not anxiety-related phenotypes across laboratories with some behaviours more sensitive to environmental factors. Environmental factors include lighting and time of day. Copyright © 2017 Elsevier B.V. All rights reserved.

Addressing ecological effects of radiation on populations and ecosystems to improve protection of the environment against radiation: Agreed statements from a Consensus Symposium

International Nuclear Information System (INIS)

Bréchignac, François; Oughton, Deborah; Mays, Claire; Barnthouse, Lawrence; Beasley, James C.; Bonisoli-Alquati, Andrea; Bradshaw, Clare; Brown, Justin; Dray, Stéphane; Geras'kin, Stanislav

2016-01-01

This paper reports the output of a consensus symposium organized by the International Union of Radioecology in November 2015. The symposium gathered an academically diverse group of 30 scientists to consider the still debated ecological impact of radiation on populations and ecosystems. Stimulated by the Chernobyl and Fukushima disasters' accidental contamination of the environment, there is increasing interest in developing environmental radiation protection frameworks. Scientific research conducted in a variety of laboratory and field settings has improved our knowledge of the effects of ionizing radiation on the environment. However, the results from such studies sometimes appear contradictory and there is disagreement about the implications for risk assessment. The Symposium discussions therefore focused on issues that might lead to different interpretations of the results, such as laboratory versus field approaches, organism versus population and ecosystemic inference strategies, dose estimation approaches and their significance under chronic exposure conditions. The participating scientists, from across the spectrum of disciplines and research areas, extending also beyond the traditional radioecology community, successfully developed a constructive spirit directed at understanding discrepancies. From the discussions, the group has derived seven consensus statements related to environmental protection against radiation, which are supplemented with some recommendations. Each of these statements is contextualized and discussed in view of contributing to the orientation and integration of future research, the results of which should yield better consensus on the ecological impact of radiation and consolidate suitable approaches for efficient radiological protection of the environment. - Highlights: • IUR built better scientific consensus on the ecological effects of radiation. • Laboratory versus field approaches have been addressed. • Organism versus

The radiation protection of workers I.R.S.N. activity in 2005 in the field of the radiation protection management

International Nuclear Information System (INIS)

Rannou, A.; Ameon, R.; Boisson, P.; Clairand, I.; Couasnon, O.; Franck, D.; Scanff, P.; Rehel, J.L.; Thevenet, M.

2008-01-01

This report presents the main work carried out by the Institute of Radiation Protection and Nuclear Safety (I.R.S.N.) in the year 2005 for the management of occupational radiological protection. It draws up an assessment for this same year of the occupational external exposures to ionizing radiation in France on the basis of passive dosimetry data transmitted to the I.R.S.N. by the approved dosimetric laboratories. (author)

Field observations and lessons learned

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Joh B [Los Alamos National Laboratory

2010-01-01

This presentation outlines observations and lessons learned from the Megaports program. It provides: (1) details of field and technical observations collected during LANL field activities at ports around the world and details of observations collected during radiation detections system testing at Los Alamos National Laboratory; (2) provides suggestions for improvement and efficiency; and (3) discusses possible program execution changes for more effective operations.

Partial body irradiation of small laboratory animals with an industrial X-ray tube

International Nuclear Information System (INIS)

Frenzel, Thorsten; Kruell, Andreas; Grohmann, Carsten; Schumacher, Udo

2014-01-01

Dedicated precise small laboratory animal irradiation sources are needed for basic cancer research and to meet this need expensive high precision radiation devices have been developed. To avoid such expenses a cost efficient way is presented to construct a device for partial body irradiation of small laboratory animals by adding specific components to an industrial X-ray tube. A custom made radiation field tube was added to an industrial 200 kV X-ray tube. A light field display as well as a monitor ionization chamber were implemented. The field size can rapidly be changed by individual inserts of MCP96 that are used for secondary collimation of the beam. Depth dose curves and cross sectional profiles were determined with the use of a custom made water phantom. More components like positioning lasers, a custom made treatment couch, and a commercial isoflurane anesthesia unit were added to complete the system. With the accessories described secondary small field sizes down to 10 by 10 mm 2 (secondary collimator size) could be achieved. The dosimetry of the beam was constructed like those for conventional stereotactical clinical linear accelerators. The water phantom created showed an accuracy of 1 mm and was well suited for all measurements. With the anesthesia unit attached to the custom made treatment couch the system is ideal for the radiation treatment of small laboratory animals like mice. It was feasible to shrink the field size of an industrial X-ray tube from whole animal irradiation to precise partial body irradiation of small laboratory animals. Even smaller secondary collimator sizes than 10 by 10 mm 2 are feasible with adequate secondary collimator inserts. Our custom made water phantom was well suited for the basic dosimetry of the X-ray tube.

Health Physics Laboratory - Overview

International Nuclear Information System (INIS)

Olko, P.

2000-01-01

Full text: The activities of the Health Physics Laboratory at the Institute of Nuclear Physics in Cracow are principally research in the general area of radiation physics, and radiation protection of the employees of the Institute of Nuclear Physics. Theoretical research concerns modelling of radiation effects in radiation detectors and studies of concepts in radiation protection. Experimental research, in the general area of solid state dosimetry, is primarily concerned with thermoluminescence (TL) dosimetry, and more specifically: development of LiF:Mg, Ti and CVD diamond detectors for medical applications in conventional and hadron radiotherapy and of LiF:Mg, Cu, P for low-level natural external ionising radiation. Environmental radiation measurements (cosmic-rays on aircraft and radon in dwellings and soil) are also performed using track CR-39 and TLD detectors. The Laboratory provides expert advice on radiation protection regulations at national and international levels. Routine work of the Health Physics Laboratory involves design and maintenance of an in-house developed TL-based personnel dosimetry system for over 200 radiation workers at the INP, supervision of radiation safety on INP premises, and advising other INP laboratories on all matters pertaining to radiation safety. We provide personal and environmental TLD dosimetry service for several customers outside the INP, mainly in hospitals and nuclear research institutes in Poland. We also calibrate radiation protection instruments for customers in southern Poland. The year 2000 was another eventful year for the Health Physics Laboratory. We started three new research projects granted by the Polish State Committee of Scientific Research. Mr P. Bilski co-ordinates the project on the measurements of radiation doses on board of commercial aircraft of Polish LOT Airlines. Dr B. Marczewska and I worked on the application of artificial diamonds for dosimetry of ionising radiation. We also participate in a

Use of mobile robots for mapping radiation field around particle accelerators

International Nuclear Information System (INIS)

Sharma, S.; Agashe, V.; Pal, P.K.