WorldWideScience

Sample records for point source radiation

  1. Distributed Sensing for Quickest Change Detection of Point Radiation Sources

    Science.gov (United States)

    2017-02-01

    paper, we consider an architecture in which each sensor node makes a local binary decision based on current observations only, binary decisions are...quickest change-point detection using a sensor network. They consider non- parametric CUSUM tests at each sensor node without an explicit statistical model of...post-change distribution is unknown and modeled as member of parametric family, one can follow a generalized likelihood ratio based approach [8] or a

  2. Application of random-point processes to the detection of radiation sources

    International Nuclear Information System (INIS)

    Woods, J.W.

    1978-01-01

    In this report the mathematical theory of random-point processes is reviewed and it is shown how use of the theory can obtain optimal solutions to the problem of detecting radiation sources. As noted, the theory also applies to image processing in low-light-level or low-count-rate situations. Paralleling Snyder's work, the theory is extended to the multichannel case of a continuous, two-dimensional (2-D), energy-time space. This extension essentially involves showing that the data are doubly stochastic Poisson (DSP) point processes in energy as well as time. Further, a new 2-D recursive formulation is presented for the radiation-detection problem with large computational savings over nonrecursive techniques when the number of channels is large (greater than or equal to 30). Finally, some adaptive strategies for on-line ''learning'' of unknown, time-varying signal and background-intensity parameters and statistics are present and discussed. These adaptive procedures apply when a complete statistical description is not available a priori

  3. Coupling aerosol-cloud-radiative processes in the WRF-Chem model: Investigating the radiative impact of elevated point sources

    Directory of Open Access Journals (Sweden)

    E. G. Chapman

    2009-02-01

    Full Text Available The local and regional influence of elevated point sources on summertime aerosol forcing and cloud-aerosol interactions in northeastern North America was investigated using the WRF-Chem community model. The direct effects of aerosols on incoming solar radiation were simulated using existing modules to relate aerosol sizes and chemical composition to aerosol optical properties. Indirect effects were simulated by adding a prognostic treatment of cloud droplet number and adding modules that activate aerosol particles to form cloud droplets, simulate aqueous-phase chemistry, and tie a two-moment treatment of cloud water (cloud water mass and cloud droplet number to precipitation and an existing radiation scheme. Fully interactive feedbacks thus were created within the modified model, with aerosols affecting cloud droplet number and cloud radiative properties, and clouds altering aerosol size and composition via aqueous processes, wet scavenging, and gas-phase-related photolytic processes. Comparisons of a baseline simulation with observations show that the model captured the general temporal cycle of aerosol optical depths (AODs and produced clouds of comparable thickness to observations at approximately the proper times and places. The model overpredicted SO2 mixing ratios and PM2.5 mass, but reproduced the range of observed SO2 to sulfate aerosol ratios, suggesting that atmospheric oxidation processes leading to aerosol sulfate formation are captured in the model. The baseline simulation was compared to a sensitivity simulation in which all emissions at model levels above the surface layer were set to zero, thus removing stack emissions. Instantaneous, site-specific differences for aerosol and cloud related properties between the two simulations could be quite large, as removing above-surface emission sources influenced when and where clouds formed within the modeling domain. When summed spatially over the finest

  4. Point Pollution Sources Dimensioning

    Directory of Open Access Journals (Sweden)

    Georgeta CUCULEANU

    2011-06-01

    Full Text Available In this paper a method for determining the main physical characteristics of the point pollution sources is presented. It can be used to find the main physical characteristics of them. The main physical characteristics of these sources are top inside source diameter and physical height. The top inside source diameter is calculated from gas flow-rate. For reckoning the physical height of the source one takes into account the relation given by the proportionality factor, defined as ratio between the plume rise and physical height of the source. The plume rise depends on the gas exit velocity and gas temperature. That relation is necessary for diminishing the environmental pollution when the production capacity of the plant varies, in comparison with the nominal one.

  5. The ciliary corona: physical model and simulation of the fine needles radiating from point light sources.

    Science.gov (United States)

    van den Berg, Thomas J T P; Hagenouw, Michiel P J; Coppens, Joris E

    2005-07-01

    Most people see, around bright lights against dark backgrounds, a radiating pattern of numerous fine, slightly colored needles of light-the so called ciliary corona. The purpose of this study was to try to explain this phenomenon. Recently, it has been shown that light-scattering in the eye, measured psychophysically and on human donor lenses, can be explained assuming the presence of specific distributions of small particles in the eye. Light entering the eye is diffracted by these particles. Each such particle causes a circular diffraction pattern on the retina of tens of degrees, much like the well-known Airy pattern. The optics of combining many such diffraction patterns was modeled and the resultant pattern simulated graphically. The simulations were compared with observations on the ciliary corona, as seen by the natural eye. The diffraction discs originating from all the particles coherently superimposed on the retina. Because of phase differences this resulted in breaking the Airy-like discs into a fine spotted pattern when monochromatic light was used. For white (polychromatic) light, the spots line up to form the very fine-line pattern seen in the ciliary corona. Details such as the width and color of the needles follow from the theoretical treatment and were demonstrated by simulations. The details of the ciliary corona can be understood on the basis of polychromatic light-scattering by the particles predicted to be present in human eye lenses on the basis of light-scattering studies of donor lenses.

  6. Sources of pulsed radiation

    International Nuclear Information System (INIS)

    Sauer, M.C. Jr.

    1981-01-01

    Characteristics of various sources of pulsed radiation are examined from the viewpoint of their importance to the radiation chemist, and some examples of uses of such sources are mentioned. A summary is given of the application of methods of physical dosimetry to pulsed sources, and the calibration of convenient chemical dosimeters by physical dosimetry is outlined. 7 figures, 1 table

  7. Effective doses in the radial gamma radiation field near a point source: gender difference and deviation from the personal dose equivalent

    International Nuclear Information System (INIS)

    Chang, Jai Kwon; Lee, Jai Ki

    1997-01-01

    The individual dose equivalent, H p , effective dose, E, and gender specific effective dose, E m , and E f , were evaluated using the male and female phantoms of MIRD type located in the radial gamma radiation field near a point source. The point sources were placed at the distances of 15, 40 and 100 cm in front of the body at different heights. Two radionuclides, 137 Cs and 131 I, were selected for the illustrative examples. In terms of the gender specific effective doses, E f is higher than E m with a few exceptions, e.g. the case where the point source is at the height of reproductive organs, but the differences from the sex- averaged values are not significant enough to justify use of gender specific dose conversion factors for the radial gamma field. The ratios H p /E were in the range of 1 to 3 depending on the source and dosimeter positions when the dosimeter is worn on the front surface of the torso covering from chest to lower abdomen, but varied from 0.34 to 6.5 in extreme cases. When it is assumed that the typical handling procedure of radioactive source material and the typical dosimeter position (on the chest) be respected, the dosimeters calibrated against the broad parallel field appear to provide estimates with acceptable errors for the effective dose of workers exposed to radial broad gamma field around a point source

  8. New sources of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schimmerling, W.

    1979-09-01

    An attempt is made to select examples of radiation sources whose application may make new or unconventional demands on radiation protection and dosimetry. A substantial body of knowledge about high energy facilities exists and, partly for this reason, the great high energy accelerators are mentioned only briefly.

  9. New sources of radiation

    International Nuclear Information System (INIS)

    Schimmerling, W.

    1979-09-01

    An attempt is made to select examples of radiation sources whose application may make new or unconventional demands on radiation protection and dosimetry. A substantial body of knowledge about high energy facilities exists and, partly for this reason, the great high energy accelerators are mentioned only briefly

  10. Comparisons between a new point kernel-based scheme and the infinite plane source assumption method for radiation calculation of deposited airborne radionuclides from nuclear power plants.

    Science.gov (United States)

    Zhang, Xiaole; Efthimiou, George; Wang, Yan; Huang, Meng

    2018-04-01

    Radiation from the deposited radionuclides is indispensable information for environmental impact assessment of nuclear power plants and emergency management during nuclear accidents. Ground shine estimation is related to multiple physical processes, including atmospheric dispersion, deposition, soil and air radiation shielding. It still remains unclear that whether the normally adopted "infinite plane" source assumption for the ground shine calculation is accurate enough, especially for the area with highly heterogeneous deposition distribution near the release point. In this study, a new ground shine calculation scheme, which accounts for both the spatial deposition distribution and the properties of air and soil layers, is developed based on point kernel method. Two sets of "detector-centered" grids are proposed and optimized for both the deposition and radiation calculations to better simulate the results measured by the detectors, which will be beneficial for the applications such as source term estimation. The evaluation against the available data of Monte Carlo methods in the literature indicates that the errors of the new scheme are within 5% for the key radionuclides in nuclear accidents. The comparisons between the new scheme and "infinite plane" assumption indicate that the assumption is tenable (relative errors within 20%) for the area located 1 km away from the release source. Within 1 km range, the assumption mainly causes errors for wet deposition and the errors are independent of rain intensities. The results suggest that the new scheme should be adopted if the detectors are within 1 km from the source under the stable atmosphere (classes E and F), or the detectors are within 500 m under slightly unstable (class C) or neutral (class D) atmosphere. Otherwise, the infinite plane assumption is reasonable since the relative errors induced by this assumption are within 20%. The results here are only based on theoretical investigations. They should

  11. Synchrotron radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    van Steenbergen, A.

    1979-01-01

    As a result of the exponential growth of the utilization of synchrotron radiation for research in the domain of the material sciences, atomic and molecular physics, biology and technology, a major construction activity has been generated towards new dedicated electron storage rings, designed optimally for synchrotron radiation applications, also, expansion programs are underway at the existing facilities, such as DORIS, SPEAR, and VEPP. In this report the basic properties of synchrotron radiation will be discussed, a short overview will be given of the existing and new facilities, some aspects of the optimization of a structure for a synchrotron radiation source will be discussed and the addition of wigglers and undulators for spectrum enhancement will be described. Finally, some parameters of an optimized synchrotron radiation source will be given.

  12. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  13. Categorization of radiation sources

    International Nuclear Information System (INIS)

    Antonova, M.

    2000-01-01

    Through one-parameter (factor) analysis it is proved a hypothesis that the value of a radiation source (RS) activity of an application correlates with the category (the rank) given to it by the IAEA categorization although it is based on other parameters of the RS applications (practices like devices with radiation sources in industry, science, medicine and agriculture). The principles of the new IAEA categorization, taking into account the potential harm the sources may cause and the necessary regulatory control, are described. (author)

  14. Tunable terahertz radiation source

    Science.gov (United States)

    Boulaevskii, Lev; Feldmann, David M; Jia, Quanxi; Koshelev, Alexei; Moody, Nathan A

    2014-01-21

    Terahertz radiation source and method of producing terahertz radiation, said source comprising a junction stack, said junction stack comprising a crystalline material comprising a plurality of self-synchronized intrinsic Josephson junctions; an electrically conductive material in contact with two opposing sides of said crystalline material; and a substrate layer disposed upon at least a portion of both the crystalline material and the electrically-conductive material, wherein the crystalline material has a c-axis which is parallel to the substrate layer, and wherein the source emits at least 1 mW of power.

  15. SYNCHROTRON RADIATION SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    HULBERT,S.L.; WILLIAMS,G.P.

    1998-07-01

    Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light.

  16. Safe handling of radiation sources

    International Nuclear Information System (INIS)

    Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

    2004-01-01

    This chapter discussed the subjects related to the safe handling of radiation sources: type of radiation sources, method of use: transport within premises, transport outside premises; Disposal of Gamma Sources

  17. Categorization of radiation sources

    International Nuclear Information System (INIS)

    2000-12-01

    The objective of this report is to develop a categorization scheme for radiation sources that could be relevant to decisions both in a retrospective application to bring sources under control and in a prospective sense to guide the application of the regulatory infrastructure. The Action Plan envisages that the preparation of guidance on national strategies and programmes for the detection and location of orphan sources and their subsequent management should commence after the categorization of sources has been carried out. In the prospective application of the system of notification, registration, and licensing, the categorization is relevant to prioritize a regulatory authority's resources and training activities; to guide the degree of detail necessary for a safety assessment; and to serve as a measure of the intensity of effort which a regulatory authority should apply to the safety and security of a particular type of source

  18. Future Synchrotron Radiation Sources

    CERN Document Server

    Winick, Herman

    2003-01-01

    Sources of synchrotron radiation (also called synchrotron light) and their associated research facilities have experienced a spectacular growth in number, performance, and breadth of application in the past two to three decades. In 1978 there were eleven electron storage rings used as light sources. Three of these were small rings, all below 500 mega-electron volts (MeV), dedicated to this purpose; the others, with energy up to 5 giga-electron volts (GeV), were used parasitically during the operation of the ring for high energy physics research. In addition, at that time synchrotron radiation from nine cyclic electron synchrotrons, with energy up to 5 GeV, was also used parasitically. At present no cyclic synchrotrons are used, while about 50 electron storage rings are in operation around the world as fully dedicated light sources for basic and applied research in a wide variety of fields. Among these fields are structural molecular biology, molecular environmental science, materials, analytic chemistry, micr...

  19. On non-radiating sources

    Science.gov (United States)

    Musafir, Ricardo E.

    2013-08-01

    Following the analysis by P.E. Doak on the radiating (active) and non-radiating (reactive) parts of a source distribution and their effect on the identification of sources, this paper discusses the possible structure of non-radiating sources, i.e., of sources which produce a null field outside the source region. It is shown that these sources can be of three types, two of them only with arbitrary time dependence. In this case, the non-radiating sources are forcibly formed by the difference of two source distributions which generate, outside the region limited by the sources in question, the same field. In the type discussed by Doak, one source distribution encircles the other and cancelation is attained as a global effect. In the other, emphasized by Ffowcs Williams, the two source distributions are superimposed and cancelation is produced locally. The latter type of non-radiating source is discussed in detail, it being shown that, while they do not represent physical sources, they provide valuable information on non-radiating effects. The third type refers to single frequency sources and involves a particular match of wavelength, geometry and source strength distribution so that the acoustic energy gets trapped inside the source region. Of these three types of non-radiating sources, only the first one—that focused by Doak—can influence the identification of the active part of a source distribution from measurements made outside the source region. Evanescent waves, associated with a purely reactive field, are also discussed. It is pointed out that evanescent waves obtained in the decomposition of the field of a vibrating body of finite extent, although useful for representing certain aspects of the field, do not exist physically. Aspects affecting the identification of sources are also briefly tackled. Can the sources be taken as essentially omnidirectional or directional features of the individual sources are important? (should the sources be represented by e

  20. Compact synchrotron radiation source

    International Nuclear Information System (INIS)

    Liu, N.; Wang, T.; Tian, J.; Lin, Y.; Chen, S.; He, W.; Hu, Y.; Li, Q.

    1985-01-01

    A compact 800 MeV synchrotron radiation source is discussed. The storage ring has a circumference of 30.3 m, two 90 degree and four 45 degree bending magnet sections, two long straight sections and four short straight sections. The radius of the bending magnet is 2.224m. The critical wave length is 24A. The injector is a 15 Mev Microtron Electrons are accelerated from 15 Mev to 800 Mev by ramping the field of the ring. The expected stored current will be around 100 ma

  1. Historical overview of the synchrotron radiation research in Japan. From the view point of creative works in the development of light sources and related technology

    International Nuclear Information System (INIS)

    Kamitsubo, Hiromichi

    2007-01-01

    Synchrotron radiation research in Japan started in early 1960's when the first electron synchrotron was commissioned at the Institute of Nuclear Study (INS), University of Tokyo (UT). This review covers the parasite use of the INS electron synchrotron and research works done at the light sources in Japan such as SOR-RING, Photon Factory (KEK-PF) Accumulator Ring (KEK-AR), and SPring-8. History of synchrotron radiation research in Japan was overviewed by paying attention to the creative works in the development of light sources and related technology, as well as the pioneering works on the development of experimental techniques and methods. At present there are more than ten synchrotron radiation sources are in operation and the number of their users, especially users from industries in Japan is increasing very rapidly and the research fields of users are also developing. Accordingly the synchrotron radiation facility becomes more and more indispensable facility in the society in Japan. (author)

  2. Natural sources of ionizing radiations

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    Natural sources of ionizing radiations are described in detail. The sources are subdivided into sources of extraterrestrial origin (cosmic radiation) and sources of terrestrial origin. Data on the concentration of different nuclides in rocks, various soils, ground waters, atmospheric air, tissues of plants and animals, various food stuffs are presented. The content of natural radionuclides in environmental objects, related to human activities, is discussed

  3. Experience with synchrotron radiation sources

    International Nuclear Information System (INIS)

    Krinsky, S.

    1987-01-01

    The development of synchrotron radiation sources is discussed, emphasizing characteristics important for x-ray microscopy. Bending magnets, wigglers and undulators are considered as sources of radiation. Operating experience at the national Synchrotron Light Source on the VUV and XRAY storage rings is reviewed, with particular consideration given to achieved current and lifetime, transverse bunch dimensions, and orbit stability. 6 refs., 3 figs

  4. Calcareous Fens - Source Feature Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Pursuant to the provisions of Minnesota Statutes, section 103G.223, this database contains points that represent calcareous fens as defined in Minnesota Rules, part...

  5. The sources of radiation exposure

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1992-01-01

    Radiation protection of workers and of members of the public requires an assessment of the various sources of exposure, their variations in time or under specific conditions or circumstances, and the possibilities for control or limitation. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has evaluated the various components of natural and man-made sources in some detail. Natural exposures form the largest component of radiation exposure of man. Variability in exposures depends on elevation, the concentrations of radionuclides in soil, food and water, the composition of building materials and the susceptibility of indoor spaces to radon build-up. Man-made sources have included exposures to fallout from atmospheric nuclear testing and discharged from nuclear fuel cycle installations in routine operations or in accidents. The other main source of radiation exposures of individuals is in medical diagnostic examinations and therapeutic treatments. (author)

  6. Compton Sources of Electromagnetic Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey Krafft,Gerd Priebe

    2011-01-01

    When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

  7. Searching for Orphan radiation sources

    International Nuclear Information System (INIS)

    Bystrov, Evgenij; Antonau, Uladzimir; Gurinovich, Uladzimir; Kazhamiakin, Valery; Petrov, Vitaly; Shulhovich, Heorhi; Tischenko, Siarhei

    2008-01-01

    Full text: The problem of orphan sources cannot be left unaddressed due high probability of accidental exposure and use of sources for terrorism. Search of objects of this kind is complex particularly when search territory is large. This requires devices capable of detecting sources, identifying their radionuclide composition, and correlating scan results to geographical coordinates and displaying results on a map. Spectral radiation scanner AT6101C can fulfill the objective of search for gamma and neutron radiation sources, radionuclide composition identification, correlation results to geographical coordinates and displaying results on a map. The scanner consists of gamma radiation scintillation detection unit based on NaI(Tl) crystal, neutron detection unit based on two He 3 counters, GPS receiver and portable ruggedized computer. Built-in and application software automates entire scan process, saving all results to memory for further analysis with visual representation of results as spectral information diagrams, count rate profile and gamma radiation dose rates on a geographical map. The scanner informs operator with voice messages on detection of radiation sources, identification result and other events. Scanner detection units and accessories are packed in a backpack. Weighing 7 kg, the scanner is human portable and can be used for scan inside cars. The scanner can also be used for radiation mapping and inspections. (author)

  8. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...

  9. Induced Temporal Signatures for Point-Source Detection

    International Nuclear Information System (INIS)

    Stephens, Daniel L.; Runkle, Robert C.; Carlson, Deborah K.; Peurrung, Anthony J.; Seifert, Allen; Wyatt, Cory R.

    2005-01-01

    Detection of radioactive point-sized sources is inherently divided into two regimes encompassing stationary and moving detectors. The two cases differ in their treatment of background radiation and its influence on detection sensitivity. In the stationary detector case the statistical fluctuation of the background determines the minimum detectable quantity. In the moving detector case the detector may be subjected to widely and irregularly varying background radiation, as a result of geographical and environmental variation. This significant systematic variation, in conjunction with the statistical variation of the background, requires a conservative threshold to be selected to yield the same false-positive rate as the stationary detection case. This results in lost detection sensitivity for real sources. This work focuses on a simple and practical modification of the detector geometry that increase point-source recognition via a distinctive temporal signature. A key part of this effort is the integrated development of both detector geometries that induce a highly distinctive signature for point sources and the development of statistical algorithms able to optimize detection of this signature amidst varying background. The identification of temporal signatures for point sources has been demonstrated and compared with the canonical method showing good results. This work demonstrates that temporal signatures are efficient at increasing point-source discrimination in a moving detector system

  10. Radiation sources working group summary

    International Nuclear Information System (INIS)

    Fazio, M.V.

    1998-01-01

    The Radiation Sources Working Group addressed advanced concepts for the generation of RF energy to power advanced accelerators. The focus of the working group included advanced sources and technologies above 17 GHz. The topics discussed included RF sources above 17 GHz, pulse compression techniques to achieve extreme peak power levels, components technology, technology limitations and physical limits, and other advanced concepts. RF sources included gyroklystrons, magnicons, free-electron masers, two beam accelerators, and gyroharmonic and traveling wave devices. Technology components discussed included advanced cathodes and electron guns, high temperature superconductors for producing magnetic fields, RF breakdown physics and mitigation, and phenomena that impact source design such as fatigue in resonant structures due to RF heating. New approaches for RF source diagnostics located internal to the source were discussed for detecting plasma and beam phenomena existing in high energy density electrodynamic systems in order to help elucidate the reasons for performance limitations

  11. Optical alignment using the Point Source Microscope

    Science.gov (United States)

    Parks, Robert E.; Kuhn, William P.

    2005-08-01

    We give an example of a Point Source Microscope (PSM) and describe its uses as an aid in the alignment of optical systems including the referencing of optical to mechanical datums. The PSM is a small package (about 100x150x30 mm), including a point source of light, beam splitter, microscope objective and digital CCD camera to detect the reflected light spot. A software package in conjunction with a computer video display locates the return image in three degrees of freedom relative to an electronic spatial reference point. The PSM also includes a Koehler illumination source so it may be used as a portable microscope for ordinary imaging and the microscope can be zoomed under computer control. For added convenience, the laser diode point source can be made quite bright to facilitate initial alignment under typical laboratory lighting conditions. The PSM is particularly useful in aligning optical systems that do not have circular symmetry or are distributed in space such as off-axis systems. The PSM is also useful for referencing the centers of curvatures of optical surfaces to mechanical datums of the structure in which the optics are mounted. By removing the microscope objective the PSM can be used as an electronic autocollimator because of the infinite conjugate optical design.

  12. Isotropic irradiation of detectors from point sources

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    1997-01-01

    NaI(Tl) scintillator detectors have been exposed to gamma rays from 8 different point sources from different directions. Background and backscatter of gamma-rays from the surroundings have been subtracted in order to produce clean spectra. By adding spectra obtained from exposures from different ...

  13. Pseudo-dynamic source modelling with 1-point and 2-point statistics of earthquake source parameters

    KAUST Repository

    Song, S. G.

    2013-12-24

    Ground motion prediction is an essential element in seismic hazard and risk analysis. Empirical ground motion prediction approaches have been widely used in the community, but efficient simulation-based ground motion prediction methods are needed to complement empirical approaches, especially in the regions with limited data constraints. Recently, dynamic rupture modelling has been successfully adopted in physics-based source and ground motion modelling, but it is still computationally demanding and many input parameters are not well constrained by observational data. Pseudo-dynamic source modelling keeps the form of kinematic modelling with its computational efficiency, but also tries to emulate the physics of source process. In this paper, we develop a statistical framework that governs the finite-fault rupture process with 1-point and 2-point statistics of source parameters in order to quantify the variability of finite source models for future scenario events. We test this method by extracting 1-point and 2-point statistics from dynamically derived source models and simulating a number of rupture scenarios, given target 1-point and 2-point statistics. We propose a new rupture model generator for stochastic source modelling with the covariance matrix constructed from target 2-point statistics, that is, auto- and cross-correlations. Our sensitivity analysis of near-source ground motions to 1-point and 2-point statistics of source parameters provides insights into relations between statistical rupture properties and ground motions. We observe that larger standard deviation and stronger correlation produce stronger peak ground motions in general. The proposed new source modelling approach will contribute to understanding the effect of earthquake source on near-source ground motion characteristics in a more quantitative and systematic way.

  14. Neutron sources for radiation oncology

    International Nuclear Information System (INIS)

    D'omyina, E.A.; Yivankova, V.S.

    2011-01-01

    The authors discuss the peculiarities of biologic effect of fast neutrons from the perspective of overcoming radioresistance of the tumor cells. Retrospective radiobiological and clinical data obtained during treatment of cancer with fast neutrons at Oncology Institute of Academy of Medical Sciences of Ukraine (now National Cancer Institute of Ministry of Health of Ukraine) are reported. It was proven that neutron therapy allows to achieve a positive effect in patients with primary tumors and relapses. 252 Cf neutrons indicated to treatment of the tumors poorly sensitive to gamma-radiation were used. 252 Cf sources were used in combination radiotherapy for cancer of endometrium and uterine cervix. The sources were introduced to the cavity and fornix of the vagina. The treatment was performed by means of alternation of distance and intracavitary radiation therapy. Complete tumor regression was achieved in almost all patients. Radiation reactions were easily controlled during the treatment. Investigation of longterm results of treatment with 252 Cf sources demonstrated that their application allowed to achieve a high and prolonged relapse-free effect.

  15. Development of a Point Pyroshock Source Simulator

    Directory of Open Access Journals (Sweden)

    Ju-won Jeong

    2017-01-01

    Full Text Available We developed a point pyroshock source simulator (PPSS for the study on the source isolation approach (SIA in this study. In spite of the potentiality of the SIA for avionics protection against pyroshock, it has rarely been investigated due to lack of pyroshock source simulators. To overcome such a situation, we proposed the PPSS using a mechanically excited tuned resonator simulating a release device itself. The PPSS was designed using explicit finite element analysis and Seigel’s gas gun model. To verify the proposed PPSS, the prototype was fabricated and tested. From the results, we have shown that the prototype of the PPSS simulates a near-field pyroshock and is able to evaluate the SIA.

  16. Radiation studies in the antiproton source

    International Nuclear Information System (INIS)

    Church, M.

    1990-01-01

    Experiment E760 has a lead glass (Pb-G) calorimeter situated in the antiproton source tunnel in the accumulator ring at location A50. This location is exposed to radiation from several sources during antiproton stacking operations. A series of radiation studies has been performed over the last two years to determine the sources of this radiation and as a result, some shielding has been installed in the antiproton source in order to protect the lead glass from radiation damage

  17. On the point-source approximation of earthquake dynamics

    Directory of Open Access Journals (Sweden)

    Andrea Bizzarri

    2014-06-01

    Full Text Available The focus on the present study is on the point-source approximation of a seismic source. First, we compare the synthetic motions on the free surface resulting from different analytical evolutions of the seismic source (the Gabor signal (G, the Bouchon ramp (B, the Cotton and Campillo ramp (CC, the Yoffe function (Y and the Liu and Archuleta function (LA. Our numerical experiments indicate that the CC and the Y functions produce synthetics with larger oscillations and correspondingly they have a higher frequency content. Moreover, the CC and the Y functions tend to produce higher peaks in the ground velocity (roughly of a factor of two. We have also found that the falloff at high frequencies is quite different: it roughly follows ω−2 in the case of G and LA functions, it decays more faster than ω−2 for the B function, while it is slow than ω−1 for both the CC and the Y solutions. Then we perform a comparison of seismic waves resulting from 3-D extended ruptures (both supershear and subshear obeying to different governing laws against those from a single point-source having the same features. It is shown that the point-source models tend to overestimate the ground motions and that they completely miss the Mach fronts emerging from the supershear transition process. When we compare the extended fault solutions against a multiple point-sources model the agreement becomes more significant, although relevant discrepancies still persist. Our results confirm that, and more importantly quantify how, the point-source approximation is unable to adequately describe the radiation emitted during a real world earthquake, even in the most idealized case of planar fault with homogeneous properties and embedded in a homogeneous, perfectly elastic medium.

  18. WADOSE, Radiation Source in Vitrification Waste Storage Apparatus

    International Nuclear Information System (INIS)

    Morita, Jun-ichi; Tashiro, Shingo; Kikkawa, Shizuo; Tsuboi, Takashi

    2007-01-01

    1 - Description of program or function: This is a radiation shielding program which analyzes unknown dose rates using known radiation sources. It can also evaluate radiation sources from measured dose rates. For instance, dose rates measured at several points in the hot cell of WASTEF are introduced into WADOS, and as a result, Ci of radiation sources and their positions are estimated with structural arrangement data of the WASTEF cells. The later functional addition is very useful for actual operation of a hot cell and others. NEA-1142/02: The code was originally written in non standard Fortran dialect and has been fully translated into Fortran 90, Fortran 77 compatible. 2 - Method of solution: Point kernel ray tracing method (the same method as QAD code). 3 - Restrictions on the complexity of the problem: Modeling of source form for input is available for cylinder, plate, point and others which are simplified geometrically

  19. Device for measuring semiconductor radiation sources

    International Nuclear Information System (INIS)

    Schubert, W.; Wendt, H.; Doss, R.

    1975-01-01

    In a measuring device, the determination of the local dependence of the intensity and/or the delay time of the recombination radiation on the radiation band of a semiconductor radiation source is reduced to phase measuring so as to enable short delays at 10 -11 seconds to be determined. The measuring device comprises an excitation source for a semiconductor radiation source, a magnifying optical system which images the semiconductor radiation source on a diaphragm having a radiation receiver in its rear. A phasemeter connected to the excitation receiver on the one hand and to the radiation receiver on the other, compares the phase of the excitation signal to the phase of the received signal. The image of the semiconductor radiation source is displaceable relatively to the diaphragm and can be viewed through an observation system. (auth)

  20. Regulatory control of radiation sources in Slovakia

    International Nuclear Information System (INIS)

    Auxtova, L.

    2001-01-01

    In Slovakia, there are two regulatory authorities. Regulatory control of the utilization of nuclear energy, based on the Slovak National Council's law No. 130/1998 on the peaceful uses of nuclear energy, is exercised by the Nuclear Regulatory Authority of the Slovak Republic. The second regulatory authority - the Ministry of Health - is empowered by law No. 72/1994 on the protection of human health to license radiation sources and is responsible for radiation protection supervision (there are nearly 3000 establishments with sealed sources, radiation generators and unsealed sources in Slovakia). Pursuant to a new radiation protection regulation based on international standards, radiation sources are to be categorized in six classes according to the associated exposure and contamination hazards. A national strategy for improving the safety of radiation sources over their life-cycle and for the management of disused and orphan sources is being prepared for governmental approval. (author)

  1. Synchrotron Radiation Therapy from a Medical Physics point of view

    Science.gov (United States)

    Prezado, Y.; Adam, J. F.; Berkvens, P.; Martinez-Rovira, I.; Fois, G.; Thengumpallil, S.; Edouard, M.; Vautrin, M.; Deman, P.; Bräuer-Krisch, E.; Renier, M.; Elleaume, H.; Estève, F.; Bravin, A.

    2010-07-01

    Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT). The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

  2. Regulation for radiation protection in applications of radiation sources

    International Nuclear Information System (INIS)

    Sonawane, Avinash U.

    2016-01-01

    Applications of ionising radiation in multifarious field are increasing in the country for the societal benefits. The national regulatory body ensures safety and security of radiation sources by enforcing provisions in the national law and other relevant rules issued under the principle law. In addition, the enforcement of detailed requirements contained in practice specific safety codes and standard and issuance of safety directives brings effectiveness in ensuring safe handling and secure management of radiation sources. The regulatory requirements for control over radiation sources throughout their life-cycle have evolved over the years from experience gained. Nevertheless, some of the regulatory activities which require special attention have been identified such as the development of regulation to deal with advance emerging radiation technology in applications of radiation in medicine and industry; sustaining continuity in ensuring human resource development programme; inspections of category 3 and 4 disused sources and their safe disposal; measures for controlling transboundary movement of radiation sources. The regulatory measures have been contemplated and are being enforced to deal with the above issues in an effective manner. The complete involvement of the management of radiation facilities, radiation workers and their commitment in establishing and maintaining safety and security culture is essential to handle the radiation sources safely and efficiently at all times

  3. Control of radiation sources in Japan

    International Nuclear Information System (INIS)

    Maki, S.

    2001-01-01

    The report refers to the regulations for radioactive material in force in Japan, and to the organizations with responsibilities for regulating radiation sources. An outline of the law regulating the use of radiation sources and radioactive materials is provided, including its scope, types of radiation sources under control, exemptions and the system of notification, authorization and inspection. The experience of Japan with orphan sources is presented in three different cases, and the measures carried out to store the orphan sources in safe conditions. (author)

  4. Nomogram for Determining Shield Thickness for Point and Line Sources of Gamma Rays

    Energy Technology Data Exchange (ETDEWEB)

    Joenemalm, C.; Malen, K

    1966-10-15

    A set of nomograms is given for the determination of the required shield thickness against gamma radiation. The sources handled are point and infinite line sources with shields of Pb, Fe, magnetite concrete (p = 3.6), ordinary concrete (p = 2.3) or water. The gamma energy range covered is 0.5 - 10 MeV. The nomograms are directly applicable for source and dose points on the surfaces of the shield. They can easily be extended to source and dose points in other positions by applying a geometrical correction. Also included are data for calculation of the source strength for the most common materials and for fission product sources.

  5. Nomogram for Determining Shield Thickness for Point and Line Sources of Gamma Rays

    International Nuclear Information System (INIS)

    Joenemalm, C.; Malen, K

    1966-10-01

    A set of nomograms is given for the determination of the required shield thickness against gamma radiation. The sources handled are point and infinite line sources with shields of Pb, Fe, magnetite concrete (p = 3.6), ordinary concrete (p = 2.3) or water. The gamma energy range covered is 0.5 - 10 MeV. The nomograms are directly applicable for source and dose points on the surfaces of the shield. They can easily be extended to source and dose points in other positions by applying a geometrical correction. Also included are data for calculation of the source strength for the most common materials and for fission product sources

  6. Regulated control of practices and radiation sources

    International Nuclear Information System (INIS)

    1992-01-01

    Excepting the radiation caused by the natural background radiation, the Executive Secretariat for Nuclear Affairs (SEAN) does not authorize any source no practice within the national territory that may imply exposure of a person to ionizing radiation unless this use is ruled. This document establishes the basic criteria to set up such system as well as to exclude or exempt practices and sources from this regulated control

  7. Warning signs for radiation sources

    International Nuclear Information System (INIS)

    2006-05-01

    This Guide provides general instructions for marking radiation equipment and radioactive materials, and the places in which they are used. In this Guide a marking means a signboard or corresponding marking made, for example, using a sticker or by painting. The Guide governs both ionizing and non-ionizing radiation. Further instructions on markings in various applications are provided in other ST Guides

  8. Training of human resources on radiation protection and safe use of radiation sources. Argentine experience

    International Nuclear Information System (INIS)

    Biaggio, Alfredo L.; Nasazzi, Nora B.; Arias, Cesar

    2004-01-01

    Argentina has a long experience in Radiation Protection training since 25 years ago. In the present work we analyse those variable and non variable training aspects according to scientific development, increasing radiation source diversity (including new concepts like orphan sources and security), mayor concern about patient in Radiation Protection, previous exposures, etc. We comment what we consider the main steps in the training of Radiation Protection specialists, like university degree, post graduate education distinguishing between formative and informative contents and on the job training. Moreover, we point out the trainees aptitudes and attitudes to be developed in order to work properly in this interdisciplinary field. (author)

  9. Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

    Energy Technology Data Exchange (ETDEWEB)

    Scott Wilde, Raymond Keegan

    2008-07-01

    The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

  10. Optoacoustic effect from a point source moving in a circular orbit

    Science.gov (United States)

    Bai, Wenyu; Diebold, Gerald J.

    2017-03-01

    The optoacoustic effect is almost invariably produced by intensity modulated radiation, typically from a pulsed or an amplitude modulated continuous source. Given the form of the wave equation that describes the production of sound from absorption of light, it is clear that steady sources of radiation that move in space in an absorbing medium can also generate acoustic waves. Here the properties of a point source of radiation that rotates in a plane at a constant angular frequency are discussed. The source is shown to generate a spiral wave pattern that contains both compressions and rarefactions.

  11. Radiation safety and inventory of sealed radiation sources in Pakistan

    International Nuclear Information System (INIS)

    Ali, M.; Mannan, A.

    2001-01-01

    Sealed radiation sources (SRS) of various types and activities are widely used in industry, medicine, agriculture, research and teaching in Pakistan. The proper maintenance of records of SRS is mandatory for users/licensees. Since 1956, more than 2000 radiation sources of different isotopes having activities of Bq to TBq have been imported. Of these, several hundred sources have been disposed of and some have been exported/returned to the suppliers. To ensure the safety and security of the sources and to control and regulate the safe use of radiation sources in various disciplines, the Directorate of Nuclear Safety and Radiation Protection (DNSRP), the implementing arm of the regulatory authority in the country, has introduced a system for notifying, registering and licensing the use of all types of SRS. In order to update the inventory of SRS used throughout the country, the DNSRP has developed a database. (author)

  12. Radiation protection and the safety of radiation sources

    International Nuclear Information System (INIS)

    1996-01-01

    These Safety Fundamentals cover the protection of human beings against ionizing radiation (gamma and X rays and alpha, beta and other particles that can induce ionization as they interact with biological materials), referred to herein subsequently as radiation, and the safety of sources that produce ionizing radiation. The Fundamentals do not apply to non-ionizing radiation such as microwave, ultraviolet, visible and infrared radiation. They do not apply either to the control of non-radiological aspects of health and safety. They are, however, part of the overall framework of health and safety

  13. Simulation of the radiation fields from ionizing radiation sources inside the containment in an accident

    Science.gov (United States)

    Kalugin, M. A.

    2010-12-01

    In the present work, a set of codes used for simulations of the radiation fields from ionizing radiation sources inside the containment in an accident is described. A method of evaluating the gamma dose rate from a space and energy distributed source is given. The dose rate is calculated by means of the design point kernel method and using buildup factors. The code MCU-REA with the ORIMCU module is used for the burnup calculations.

  14. Radiation sources and methods for producing them

    International Nuclear Information System (INIS)

    Malson, H.A.; Moyer, S.E.; Honious, H.B.; Janzow, E.F.

    1979-01-01

    The radiation sources contain a substrate with an electrically conducting, non-radioactive metal surface, a layer of a metal isotope of the scandium group as well as a percentage of non-radioactive binding metal being coated on the surface by means of an electroplating method. Besides examples for β sources ( 147 Pm), γ sources ( 241 Am), and neutron sources ( 252 Cf) there is described an α-radiation source ( 241 Am, 244 Cu, 238 Pu) for smoke detectors. There are given extensive tables and a bibliography. (DG) [de

  15. Sources of radiation exposure - an overview

    International Nuclear Information System (INIS)

    Mason, G.C.

    1990-01-01

    Sources of radiation exposure are reviewed from the perspective of mining and milling of radioactive ores in Australia. The major sources of occupational and public exposure are identified and described, and exposures from mining and milling operations are discussed in the context of natural radiation sources and other sources arising from human activities. Most radiation exposure of humans comes from natural sources. About 80% of the world average of the effective dose equivalents received by individual people arises from natural radiation, with a further 15-20% coming from medical exposures*. Exposures results from human activities, such as mining and milling of radioactive ores, nuclear power generation, fallout from nuclear weapons testing and non-medical use of radioisotopes and X-rays, add less than 1% to the total. 9 refs., 4 tabs., 10 figs

  16. All-fiber femtosecond Cherenkov radiation source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe

    2012-01-01

    An all-fiber femtosecond source of spectrally isolated Cherenkov radiation is reported, to the best of our knowledge, for the first time. Using a monolithic, self-starting femtosecond Yb-doped fiber laser as the pump source and the combination of photonic crystal fibers as the wave......-conversion medium, we demonstrate milliwatt-level, stable, and tunable Cherenkov radiation at visible wavelengths 580–630 nm, with pulse duration of sub-160-fs, and the 3 dB spectral bandwidth not exceeding 36 nm. Such an all-fiber Cherenkov radiation source is promising for practical applications in biophotonics...

  17. There are radiation sources out there!

    International Nuclear Information System (INIS)

    Bahran, M.Y.

    2001-01-01

    During the past few years we have been working in the area of the safety of radiation sources and radioactive materials. In this paper we summarize our findings and describe the recovery of an abandoned source. We call for further international co-operation in this area. In particular, we suggest an international system for the tagging and tracking of radioactive sources. (author)

  18. Ionizing radiation sources. Ionizing radiation interaction with matter

    International Nuclear Information System (INIS)

    Popits, R.

    1976-01-01

    Fundamentals of nuclear physics are reviewed under the headings: obtaining of X-rays and their properties; modes of radioactive decay of natural or man-made radionuclides; radioactive neutron sources; nuclear fission as basis for devising nuclear reactors and weapons; thermonuclear reactions; cosmic radiation. Basic aspects of ionizing radiation interactions with matter are considered with regard to charged particles, photon radiation, and neutrons. (A.B.)

  19. Radiation sources and technical services

    International Nuclear Information System (INIS)

    Stonek, K.; Satorie, Z.; Vyskocil, I.

    1981-01-01

    Work is briefly described of the department for sealed sources production of the Institute, including leak testing and surface contamination of sealed sources. The department also provides technical services including the inspections of sealed sources used in medicine and geology and repair of damaged sources. It carries out research of the mechanical and thermal strength of sealed sources and of the possibility of reprocessing used 226 Ra sources. The despatch department is responsible for supplying the entire country with home and imported radionuclides. The department of technical services is responsible for testing imported radionuclides, assembling materials testing, industrial and medical irradiation devices, and for the collection and storage of low-level wastes on a national scale. (M.D.)

  20. BEAMLINE-CONTROLLED STEERING OF SOURCE-POINT ANGLE AT THE ADVANCED PHOTON SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Emery, L.; Fystro, G.; Shang, H.; Smith, M.

    2017-06-25

    An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering given by the value of the "angle request" EPICS record. The new system makes the steering process much faster than before, although the older steering protocols can still be used. The robustness features of the original steering remain. Feedback messages are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinement of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way.

  1. Radiation Safety and Orphan Sources

    International Nuclear Information System (INIS)

    Janzekovic, H.; Krizman, M.

    2006-01-01

    The wide spread use of radioactive and particularly of nuclear materials which started in the last century very quickly also demonstrated negative sides. The external exposure and radiotoxicity of these materials could be easily used in a malevolent act. Due to the fact that these materials could not be detected without special equipment designed for that purpose, severe control over their use in all phases of a life cycle is required. An orphan source is a radioactive source which is not under regulatory control, either because it has never been under regulatory or because it has been abandoned, lost, misplaced, stolen or transferred without proper authorization. In the last ten years a few international conferences were dedicated to the improvement of the safety and security of radioactive sources. Three main tasks are focused, the maintenance of data bases related to events with orphan sources and the publications of such events, the preparation of recommendations and guidelines to national regulatory bodies in order to prevent and detect the events related to orphan sources as well as to develop the response strategies to radiological or nuclear emergency, appraisals of the national strategies of radioactive sources control. Concerning Slovenia, strengthening control over orphan sources in Slovenia started after the adoption of new legislation in 2002. It was carried out through several tasks with the aim to prevent orphan sources, as well as to identify the sources which could be potentially orphan sources. The comprehensive methodology was developed by the Slovenian nuclear safety administration (S.N.S.A.) based on international guidelines as well as on the study of national lesson learned cases. The methodology was developed and used in close cooperation with all parties involved, namely other regulatory authorities, police, customs, agency for radioactive waste management (A.R.A.O.), technical support organisations (T.S.O.), users of source, authorised

  2. The utilization of radiation sources in Angola

    International Nuclear Information System (INIS)

    Lemos, P.C.D.

    2001-01-01

    The report describes the situation that Angola, which joined the IAEA in September 1999, is facing with the lack of an appropriate infrastructure for the control of radiation sources. It emphasizes the country's needs in technical assistance from the IAEA and other Member States for improving its regulatory infrastructure for radiation safety. (author)

  3. Characteristics of a multi-keV monochromatic point x-ray source ...

    Indian Academy of Sciences (India)

    Temporal, spatial and spectral characteristics of a multi-keV monochromatic point x-ray source based on vacuum diode with laser-produced plasma as cathode are presented. Electrons from a laser-produced aluminium plasma were accelerated towards a conical point tip titanium anode to generate K-shell x-ray radiation.

  4. Characteristics of a multi-keV monochromatic point x-ray source

    Indian Academy of Sciences (India)

    Temporal, spatial and spectral characteristics of a multi-keV monochromatic point x-ray source based on vacuum diode with laser-produced plasma as cathode are presented. Electrons from a laser-produced aluminium plasma were accelerated towards a conical point tip titanium anode to generate K-shell x-ray radiation.

  5. Radiation therapy sources, equipment and installations

    International Nuclear Information System (INIS)

    2011-03-01

    The safety code for Telegamma Therapy Equipment and Installations, (AERB/SC/MED-1) and safety code for Brachytherapy Sources, Equipment and Installations, (AERB/SC/MED-3) were issued by AERB in 1986 and 1988 respectively. These codes specified mandatory requirements for radiation therapy facilities, covering the entire spectrum of operations ranging from the setting up of a facility to its ultimate decommissioning, including procedures to be followed during emergency situations. The codes also stipulated requirements of personnel and their responsibilities. With the advent of new techniques and equipment such as 3D-conformal radiation therapy, intensity modulated radiation therapy, image guided radiation therapy, treatment planning system, stereotactic radiosurgery, stereotactic radiotherapy, portal imaging, integrated brachytherapy and endovascular brachytherapy during the last two decades, AERB desires that these codes be revised and merged into a single code titled Radiation Therapy Sources, Equipment, and Installations

  6. Regulatory control of radiation sources. Safety guide

    International Nuclear Information System (INIS)

    2004-01-01

    The basic requirements for the protection of persons against exposure to ionizing radiation and for the safety of radiation sources were established in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Basic Safety Standards), jointly sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Atomic Energy Agency (IAEA), the International Labour Organization (ILO), the OECD Nuclear Energy Agency (OECD/ NEA), the Pan American Health Organization (PAHO) and the World Health Organization (WHO) (the Sponsoring Organizations). The application of the Basic Safety Standards is based on the presumption that national infrastructures are in place to enable governments to discharge their responsibilities for radiation protection and safety. Requirements relating to the legal and governmental infrastructure for the safety of nuclear facilities and sources of ionizing radiation, radiation protection, the safe management of radioactive waste and the safe transport of radioactive material are established in the Safety Requirements on Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, Safety Standards Series No. GS-R-1. This Safety Guide, which is jointly sponsored by the FAO, the IAEA, the International Labour Office, the PAHO and the WHO, gives detailed guidance on the key elements for the organization and operation of a national regulatory infrastructure for radiation safety, with particular reference to the functions of the national regulatory body that are necessary to ensure the implementation of the Basic Safety Standards. The Safety Guide is based technically on material first published in IAEA-TECDOC-10671, which was jointly sponsored by the FAO, the IAEA, the OECD/NEA, the PAHO and the WHO. The requirements established in GS-R-1 have been taken into account. The Safety Guide is oriented towards national

  7. Ionization detector with improved radiation source

    International Nuclear Information System (INIS)

    Solomon, E.F.

    1977-01-01

    The detector comprises a chamber having at least one radiation source disposed therein. The chamber includes spaced collector plates which form a part of a detection circuit for sensing changes in the ionization current in the chamber. The radiation source in one embodiment is in the form of a wound wire or ribbon suitably supported in the chamber and preferably a source of beta particles. The chamber may also include an adjustable electrode and the source may function as an adjustable current source by forming the wire or ribbon in an eliptical shape and rotating the structure. In another embodiment the source has a random shape and is homogeneously disposed in the chamber. 13 claims, 5 drawing figures

  8. Safe management of spent radiation source

    International Nuclear Information System (INIS)

    Kosako, Toshiso; Sugiura, Nobuyuki; Valdezco, E.M.; Choi, Kwang-Sub

    2003-01-01

    Presented are 8 investigation reports concerning the safe management of spent radiation source (SRS) during the current 2 years. Four reports from Japan are: Scheme for SRS management (approach and present status of the SRS management and consideration toward solving problems); Current International Atomic Energy Agency (IAEA) activities related to safety of radiation sources (Chronology of action plan development, Outline of revised action plan, and Asian regional activities); Current status of SRS management in Japan (Regulation system, Obligations of licensed users, Regulatory system on sealed sources, Status in the incidents on sources occurred, Incident of source loss, and Incidents of orphan sources); and SRS management system in Japan (Current status of using of sealed sources, collection system of SRS-Japan Radioisotope Association (JRIA) services, and Disposal of SRS). Four reports from the Asian countries also concern the current statuses of SRS management in the Philippine (Radioactive waste sources, Waste management strategies, Conditioning of Ra sources, Ra project action plan, as low as reasonably achievable (ALARA) program, Dose assessment, Regulations on radioactive waste, Action plan on the safety and security of sources, IAEA Regional Demonstration Centers, and sitting studies for a near surface disposal facility); Thailand (Current status of using sealed sources, Inventory of SRS, and Current topics of SRS management); Indonesia (Principles of management of radiation sources, Legislative framework of SRS management practices, Regulatory on SRS, management of sealed SRS, management hurdles, and reported incidents); and Korea (Regulatory frame work, Collection systems of SRS, Radioisotope waste generation, Radiation exposure incident, and Scrap monitoring system). (N.I.)

  9. The safe use of radiation sources

    International Nuclear Information System (INIS)

    1995-01-01

    As a means of promoting safety in the use of radiation sources, as well as encouraging consistency in regulatory control, the IAEA has from time to time organized training courses with the co-operation of Member State governments and organizations, to inform individuals from developing countries with appropriate responsibilities on the provisions for the safe use and regulation of radiation sources. Three such courses on the safe use of radiation sources have been held in both the USA, with the co-operation of the United States Government, and in Dublin, Ireland, with the co-operation of the Irish Government. The Training Course on the Safe Use and Regulation of Radiation Sources has been successfully given to over 77 participants from over 30 countries during the last years. The course is aimed at providing a basis of radiation protection knowledge in all aspects of the uses of radiation and of radiation sources that are used today. It is the intention of this course to provide a systematic enhancement of radioisotope safety in countries with developing radiological programmes through a core group of national authorities. The IAEA's training programmes provide an excellent opportunity for direct contact with lecturers that have extensive experience in resolving issues faced by developing countries and in providing guidance documents useful in addressing their problems. This document uses this collective experience and provides valuable technical information regarding the safety aspects of the uses not only of sealed and unsealed sources of radiation, but also for those machines that produce ionizing radiation. The first of these training courses, 'Safety and Regulation of Unsealed Sources' was held in Dublin, Ireland, June through July 1989 with the co-operation of the Nuclear Energy Board and Trinity College. This was an interregional training course, the participants came from all over the world. The second and third interregional courses, 'Safety and Regulation

  10. New high power coherent radiation sources

    Science.gov (United States)

    Sprangle, P.; Coffey, T.

    1984-01-01

    In recent years, there has been considerable renewed interest in the development of novel devices for the production of high power coherent electromagnetic radiation. This interest has been motivated largely by the realization that, with existing technology, certain processes utilizing relativistic electron beams can produce coherent electromagnetic radiation at power levels far in excess of those achieved by conventional electron devices. This paper will review the current status of this rapidly developing field, with emphasis on two generic devices. The major thrust in the recent development of electron beam driven radiation sources has been directed towards achieving shorter wavelengths, greater power and higher efficiencies. Shortly after the development of such successful sources as the magnetron, kylstron and various traveling wave devices, it became clear that, in their original form, they were limited in their ability to produce high levels of radiation efficiently at short wavelengths. To circumvent the inherent limitations of these conventional coherent radiation sources, many new concepts and mechanisms, as well as variations on conventional concepts, were proposed. This paper is concerned primarily with two devices which are, relatively speaking, newcomers to the list of coherent classical radiation sources. They are the free electron laser and the cyclotron resonance maser (CRM); one well known type of CRM is the gyrotron.

  11. Observation of annihilation radiation from the Galactic center - The point and ridge components

    Science.gov (United States)

    Gruber, D. E.; Briggs, M. S.

    1991-01-01

    The point-source and Galactic-ridge components of the 511-keV annihilation radiation from the Galactic center are evaluated with an all-sky map based on detection at 80 keV through 2 MeV. The point-source flux is shown to be significant at 95-percent confidence and to agree with those of other data, while the ridge component is consistent with measurements taken at 25-deg longitude.

  12. [UV-radiation--sources, wavelength, environment].

    Science.gov (United States)

    Hölzle, Erhard; Hönigsmann, Herbert

    2005-09-01

    The UV-radiation in our environment is part of the electromagnetic radiation, which emanates from the sun. It is designated as optical radiation and reaches from 290-4,000 nm on the earth's surface. According to international definitions UV irradiation is divided into short-wave UVC (200-280 nm), medium-wave UVB (280-320 nm), and long-wave UVA (320-400 nm). Solar radiation which reaches the surface of the globe at a defined geographical site and a defined time point is called global radiation. It is modified quantitatively and qualitatively while penetrating the atmosphere. Besides atmospheric conditions, like ozone layer and air pollution, geographic latitude, elevation, time of the season, time of the day, cloudiness and the influence of indirect radiation resulting from stray effects in the atmosphere and reflection from the underground play a role in modifying global radiation, which finally represents the biologically effective radiation. The radiation's distribution on the body surface varies according to sun angle and body posture. The cumulative UV exposure is mainly influenced by outdoor profession and recreational activities. The use of sun beds and phototherapeutic measures additionally may contribute to the cumulative UV dose.

  13. Concept for Risk-based Prioritisation of Point Sources

    DEFF Research Database (Denmark)

    Overheu, N.D.; Troldborg, Mads; Tuxen, N.

    2010-01-01

    estimates on a local scale from all the sources, and 3D catchment-scale fate and transport modelling. It handles point sources at various knowledge levels and accounts for uncertainties. The tool estimates the impacts on the water supply in the catchment and provides an overall prioritisation of the sites......A large number of point sources pose a threat to ground water resources. A new tool is presented which enables a uniform and transparent risk assessment and prioritisation of these point sources at the catchment scale. The tool integrates aquifer vulnerability mapping, site-specific mass flux...

  14. Assessment of risk from radiation sources

    International Nuclear Information System (INIS)

    Subbaratnam, T.; Madhvanath, U.; Somasundaram, S.

    1976-01-01

    Assessment of risk from exposure to ionizing radiations from man-made radiation sources and nuclear installations has to be viewed from three aspects, namely, dose-effect relationship (genetic and somatic) for humans, calculation of doses or dose-commitments to population groups, assessment of risk to radiation workers and the population at large from the current levels of exposure from nuclear industry and comparison of risk estimates with other industries in a modern society. These aspects are discussed in brief. On the basis of available data, it is shown that estimated incidence of genetic diseases and cancers due to exposure of population to radiation from nuclear industry is negligible in comparison with their natural incidence, and radiation risks to the workers in nuclear industry are much lower than the risks in other occupations. (M.G.B.)

  15. Heat radiation and transfer for point particles in arbitrary geometries

    Science.gov (United States)

    Asheichyk, Kiryl; Müller, Boris; Krüger, Matthias

    2017-10-01

    We study heat radiation and heat transfer for pointlike particles in a system of other objects. Starting from exact many-body expressions found from scattering theory and fluctuational electrodynamics, we find that transfer and radiation for point particles are given in terms of the Green's function of the system in the absence of the point particles. These general expressions contain no approximation for the surrounding objects. As an application, we compute the heat transfer between two point particles in the presence of a sphere of arbitrary size and show that the transfer is enhanced by several orders of magnitude through the presence of the sphere, depending on the materials. Furthermore, we compute the heat emission of a point particle in front of a planar mirror. Finally, we show that a particle placed inside a spherical mirror cavity does not radiate energy.

  16. Occupational exposure to natural sources of radiation

    International Nuclear Information System (INIS)

    Ortiz, T.; Sciocchetti, G.; Rannou, A.

    1993-01-01

    The most important natural sources of radiation are analyzed. The situation in France, Italy, and Spain concerning protection against natural radiation is described, including the identification of sources, and defined practices, organizations charged of national surveys and the responsibility of regulatory bodies and the role of operating management. The activities of the international organizations (ICRP, CEC and IAEA) are presented and discussed, and existing actions toward harmonization in the CEC, IAEA and other international programs is also discussed. (R.P.) 23 refs., 2 tabs

  17. Sustainably Sourced, Thermally Resistant, Radiation Hard Biopolymer

    Science.gov (United States)

    Pugel, Diane

    2011-01-01

    This material represents a breakthrough in the production, manufacturing, and application of thermal protection system (TPS) materials and radiation shielding, as this represents the first effort to develop a non-metallic, non-ceramic, biomaterial-based, sustainable TPS with the capability to also act as radiation shielding. Until now, the standing philosophy for radiation shielding involved carrying the shielding at liftoff or utilizing onboard water sources. This shielding material could be grown onboard and applied as needed prior to different radiation landscapes (commonly seen during missions involving gravitational assists). The material is a bioplastic material. Bioplastics are any combination of a biopolymer and a plasticizer. In this case, the biopolymer is a starch-based material and a commonly accessible plasticizer. Starch molecules are composed of two major polymers: amylase and amylopectin. The biopolymer phenolic compounds are common to the ablative thermal protection system family of materials. With similar constituents come similar chemical ablation processes, with the potential to have comparable, if not better, ablation characteristics. It can also be used as a flame-resistant barrier for commercial applications in buildings, homes, cars, and heater firewall material. The biopolymer is observed to undergo chemical transformations (oxidative and structural degradation) at radiation doses that are 1,000 times the maximum dose of an unmanned mission (10-25 Mrad), indicating that it would be a viable candidate for robust radiation shielding. As a comparison, the total integrated radiation dose for a three-year manned mission to Mars is 0.1 krad, far below the radiation limit at which starch molecules degrade. For electron radiation, the biopolymer starches show minimal deterioration when exposed to energies greater than 180 keV. This flame-resistant, thermal-insulating material is non-hazardous and may be sustainably sourced. It poses no hazardous

  18. Synchrotron radiation sources in the Soviet Union

    International Nuclear Information System (INIS)

    Kapitza, S.P.

    1987-01-01

    Synchrotron radiation (SR) is now recognized to be an important instrument for experimental work in many fields of science. Recently the application of SR in medicine and industry, especially as a light source for microelectronics production have been demonstrated. Thus the development of SR sources has now grown to become a significant and independent dimension for accelerator research and technology. This article describes SR work in the Soviet Union

  19. Radiation as a source of risk

    International Nuclear Information System (INIS)

    Katoh, Kazuaki

    1999-01-01

    Essence and nature of ionizing radiation as a source of risk are reviewed. Following to the appeal of necessity and importance of campaign for enlightening risk management, of individual and of society, background knowledge and information helpful to the promotion and discussion are summarized, also. (author)

  20. Trade and transport of radiation sources

    International Nuclear Information System (INIS)

    1996-01-01

    The guide specifies the obligations pertaining to the trade in and transport of radiation sources and other matters to be taken into account in safety supervision. It also specifies obligations and procedures relating to transfrontier movements of radioactive waste contained in the EU Council Directive 92/3/Euratom. (7 refs.)

  1. Laser ranging using safety radiation sources

    Science.gov (United States)

    Stavrov, A. A.; Pozdniakov, M. G.

    2004-02-01

    Impulse laser rangefinders (ILR) on the basis of coherent radiation sources with various spectral structure characteristics complex analysis results are stated. Hardware and tehnological ILR realization opportunities with both located objects and information light streams extending environment (atmosphere) typical characteristics so as levels of probing optical signals biological influence are taken into account.

  2. Optimization of industrial processes using radiation sources

    International Nuclear Information System (INIS)

    Salles, Claudio G.; Silva Filho, Edmundo D. da; Toribio, Norberto M.; Gandara, Leonardo A.

    1996-01-01

    Aiming the enhancement of the staff protection against radiation in operational areas, the SAMARCO Mineracao S.A. proceeded a reevaluation and analysis of the real necessity of the densimeters/radioactive sources in the operational area, and also the development of an alternative control process for measurement the ore pulp, and introduced of the advanced equipment for sample chemical analysis

  3. Aircrew radiation exposure: sources-risks-measurement

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1994-05-01

    A short review is given on the actual aircrew exposure and its sources. The resulting risks for harmful effects to the health and discuss methods for in-flight measurements of exposure is evaluated. An idea for a fairly simple and economic approach to a practical, airborne active dosimeter for the assessment of individual crew exposure is presented. The exposure of civil aircrew to cosmic radiation, should not be considered a tremendous risk to the health, there is no reason for panic. However, being significantly higher than the average exposure to radiation workers, it can certainly not be neglected. As recommended by ICRP, aircrew exposure has to be considered occupational radiation exposure and aircrews are certainly entitled to the same degree of protection, as other ground-based radiation workers have obtained by law, since long time. (author)

  4. Radiation problems expected for the German spallation neutron source

    International Nuclear Information System (INIS)

    Goebel, K.

    1981-01-01

    The German project for the construction of a Spallation Neutron Source with high proton beam power (5.5 MW) will have to cope with a number of radiation problems. The present report describes these problems and proposes solutions for keeping exposures for the staff and release of activity and radiation into the environment as low as reasonably achievable. It is shown that the strict requirements of the German radiation protection regulations can be met. The main problem will be the exposure of maintenance personnel to remanent gamma radiation, as is the case at existing proton accelerators. Closed ventilation and cooling systems will reduce the release of (mainly short-lived) activity to acceptable levels. Shielding requirements for different sections are discussed, and it is demonstrated by calculations and extrapolations from experiments that fence-post doses well below 150 mrem/y can be obtained at distances of the order of 100 metres from the principal source points. The radiation protection system proposed for the Spallation Neutron Source is discussed, in particular the needs for monitor systems and a central radiation protection data base and alarm system. (orig.)

  5. Low energy electron point source microscopy: beyond imaging.

    Science.gov (United States)

    Beyer, André; Gölzhäuser, Armin

    2010-09-01

    Low energy electron point source (LEEPS) microscopy has the capability to record in-line holograms at very high magnifications with a fairly simple set-up. After the holograms are numerically reconstructed, structural features with the size of about 2 nm can be resolved. The achievement of an even higher resolution has been predicted. However, a number of obstacles are known to impede the realization of this goal, for example the presence of electric fields around the imaged object, electrostatic charging or radiation induced processes. This topical review gives an overview of the achievements as well as the difficulties in the efforts to shift the resolution limit of LEEPS microscopy towards the atomic level. A special emphasis is laid on the high sensitivity of low energy electrons to electrical fields, which limits the structural determination of the imaged objects. On the other hand, the investigation of the electrical field around objects of known structure is very useful for other tasks and LEEPS microscopy can be extended beyond the task of imaging. The determination of the electrical resistance of individual nanowires can be achieved by a proper analysis of the corresponding LEEPS micrographs. This conductivity imaging may be a very useful application for LEEPS microscopes.

  6. Compact high-power terahertz radiation source

    Directory of Open Access Journals (Sweden)

    G. A. Krafft

    2004-06-01

    Full Text Available In this paper a new type of THz radiation source, based on recirculating an electron beam through a high gradient superconducting radio frequency cavity, and using this beam to drive a standard electromagnetic undulator on the return leg, is discussed. Because the beam is recirculated and not stored, short bunches may be produced that radiate coherently in the undulator, yielding exceptionally high average THz power for relatively low average beam power. Deceleration from the coherent emission, and the detuning it causes, limits the charge-per-bunch possible in such a device.

  7. Radiation source shielding and collimating device

    International Nuclear Information System (INIS)

    Garrett, R.E.

    1978-01-01

    A radiation source, such as 241 Am, sealed in a capsule at atmospheric pressure especially for use in agricultural machines such as lettuce harvesters having a maturity tester is described. The capsule is disposed in a plunger movable in an evacuated chamber between a first position in alignment with a passage having a window permeable by radiation to the outside and a second position in which the capsule is out of alignment with the passage. A pressure responsive switch monitors the pressure in the chamber and affords an alarm if the chamber pressure rises

  8. 2011 Radioactive Materials Usage Survey for Unmonitored Point Sources

    Energy Technology Data Exchange (ETDEWEB)

    Sturgeon, Richard W. [Los Alamos National Laboratory

    2012-06-27

    This report provides the results of the 2011 Radioactive Materials Usage Survey for Unmonitored Point Sources (RMUS), which was updated by the Environmental Protection (ENV) Division's Environmental Stewardship (ES) at Los Alamos National Laboratory (LANL). ES classifies LANL emission sources into one of four Tiers, based on the potential effective dose equivalent (PEDE) calculated for each point source. Detailed descriptions of these tiers are provided in Section 3. The usage survey is conducted annually; in odd-numbered years the survey addresses all monitored and unmonitored point sources and in even-numbered years it addresses all Tier III and various selected other sources. This graded approach was designed to ensure that the appropriate emphasis is placed on point sources that have higher potential emissions to the environment. For calendar year (CY) 2011, ES has divided the usage survey into two distinct reports, one covering the monitored point sources (to be completed later this year) and this report covering all unmonitored point sources. This usage survey includes the following release points: (1) all unmonitored sources identified in the 2010 usage survey, (2) any new release points identified through the new project review (NPR) process, and (3) other release points as designated by the Rad-NESHAP Team Leader. Data for all unmonitored point sources at LANL is stored in the survey files at ES. LANL uses this survey data to help demonstrate compliance with Clean Air Act radioactive air emissions regulations (40 CFR 61, Subpart H). The remainder of this introduction provides a brief description of the information contained in each section. Section 2 of this report describes the methods that were employed for gathering usage survey data and for calculating usage, emissions, and dose for these point sources. It also references the appropriate ES procedures for further information. Section 3 describes the RMUS and explains how the survey results are

  9. Pulsewidth-modulated 2-source neutral-point-clamped inverter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, Poh Chang; Gao, Feng

    2007-01-01

    This paper presents the careful integration of a newly proposed Z-source topological concept to the basic neutral-point-clamped (NPC) inverter topology for designing a three-level inverter with both voltage-buck and voltage-boost capabilities. The designed Z-source NPC inverter uses two unique X-...

  10. Trans-Z-source Neutral Point Clamped inverter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P. C.; Li, D.

    2012-01-01

    for buck-boost energy conversion with all the favourable advantages of multi-level switching retained. This paper presents three-level trans-Z-source Neutral Point Clamped (NPC) inverter topology, which achieves both the advantages of trans-Z-source and three-level NPC inverter configuration. With proper...

  11. Radiative symmetry breaking from interacting UV fixed points

    DEFF Research Database (Denmark)

    Abel, Steven; Sannino, Francesco

    2017-01-01

    It is shown that the addition of positive mass-squared terms to asymptotically safe gauge-Yukawa theories with perturbative UV fixed points leads to calculable radiative symmetry breaking in the IR. This phenomenon, and the multiplicative running of the operators that lies behind it, is akin...

  12. The resolution of point sources of light as analyzed by quantum detection theory

    Science.gov (United States)

    Helstrom, C. W.

    1972-01-01

    The resolvability of point sources of incoherent light is analyzed by quantum detection theory in terms of two hypothesis-testing problems. In the first, the observer must decide whether there are two sources of equal radiant power at given locations, or whether there is only one source of twice the power located midway between them. In the second problem, either one, but not both, of two point sources is radiating, and the observer must decide which it is. The decisions are based on optimum processing of the electromagnetic field at the aperture of an optical instrument. In both problems the density operators of the field under the two hypotheses do not commute. The error probabilities, determined as functions of the separation of the points and the mean number of received photons, characterize the ultimate resolvability of the sources.

  13. Resolution of point sources of light as analyzed by quantum detection theory.

    Science.gov (United States)

    Helstrom, C. W.

    1973-01-01

    The resolvability of point sources of incoherent thermal light is analyzed by quantum detection theory in terms of two hypothesis-testing problems. In the first, the observer must decide whether there are two sources of equal radiant power at given locations, or whether there is only one source of twice the power located midway between them. In the second problem, either one, but not both, of two point sources is radiating, and the observer must decide which it is. The decisions are based on optimum processing of the electromagnetic field at the aperture of an optical instrument. In both problems the density operators of the field under the two hypotheses do not commute. The error probabilities, determined as functions of the separation of the points and the mean number of received photons, characterize the ultimate resolvability of the sources.

  14. Applications and opportunities for radiation sources

    International Nuclear Information System (INIS)

    Round, K.J.

    1984-01-01

    An important spin-off benefit from the nuclear industry has been the ability to produce a wide variety of ionizing radiation sources for industrial, medical and scientific applications. These sources include radionuclides produced by irradiation of target material in reactors and cyclotrons or recovered from spent fuels, and accelerators. The uses of radiation in both medicine and industry can be expected to evolve. Traditional uses such as cancer therapy will mature and in some cases be displaced by new technology. Major new applications, including food processing and waste treatment, are expected to maintain the demand for isotopes such as cobalt 60 and to stimulate the development of economical and reliable accelerator systems. (L.L.) (Tab., 2 figs.)

  15. Regulation of radiation sources in Canada

    International Nuclear Information System (INIS)

    Brown, W.R.

    1989-04-01

    This paper describes in general the Canadian program for the regulation of radiation sources, with particular emphasis on radioisotope licences. The Atomic Energy Control Board is described, as are the most significant parts of the Regulations. Licensing, which is the method chosen for control, is explained by describing the assessment of an application through the enforcement of the requirements, and the overall effectiveness of the program is measured by analyzing the incidents and overexposures that have occurred in recent years

  16. Safety of radiation sources in Slovenia

    International Nuclear Information System (INIS)

    Belicic-Kolsek, A.; Sutej, T.

    2001-01-01

    The Republic of Slovenia, a central European country which has been independent since 1991, has about 2 million inhabitants and an area of 20,256 km 2 . The Constitutional Law on Enforcement of the Basic Constitutional Charter on the Autonomy and Independence of the Republic of Slovenia, adopted on 23 June 1991 (Off. Gaz. of the R of Slovenia No. 1/91), provided that all the laws adopted by the Socialist Federal Republic (SFR) of Yugoslavia should remain in force in the Republic of Slovenia pending the adoption of appropriate legislation by the Slovene Parliament. Under the Slovene Constitution, all international treaties ratified by Slovenia constitute an integral part of Slovenia's legislation and can be applied directly. In Slovenia, all regular types of ionizing radiation source are being used for peaceful purposes and are covered by a system for their safe use and control. All radiation sources and radioactive materials are registered and under regulatory control. Inspections are carried out periodically by the Health Inspectorate of the Republic of Slovenia (HIRS) and, in the case of nuclear installations, the Slovene Nuclear Safety Administration (SNSA). Technical checks on radiation sources are carried out periodically by technical support organizations: the Jozef Stefan Institute and the Institute for Occupational Safety (IOS). (author)

  17. The distribution of infrared point sources in nearby elliptical galaxies

    Science.gov (United States)

    Gogoi, Rupjyoti; Shalima, P.; Misra, Ranjeev

    2018-02-01

    Infrared (IR) point sources as observed by Spitzer, in nearby early-type galaxies should either be bright sources in the galaxy such as globular clusters, or they may be background sources such as AGNs. These objects are often counterparts of sources in other wavebands such as optical and X-rays and the IR information provides crucial information regarding their nature. However, many of the IR sources may be background objects and it is important to identify them or at least quantify the level of background contamination. Moreover, the distribution of these IR point sources in flux, distance from the centre and colour would be useful in understanding their origin. Archival Spitzer IRAC images provide a unique opportunity for such a study and here we present the results of such an analysis for four nearby galaxies, NGC 1399, NGC 2768, NGC 4365 and NGC 4649. We estimate the background contamination using several blank fields. Our results suggest that IR colours can be effectively used to differentiate between sources in the galaxy and background ones. In particular we find that sources having AGN like colours are indeed consistent with being background AGNs. For sources with non AGN like colours we compute the distribution of flux and normalised distance from the centre which is found to be of a power-law form. Although our sample size is small, the power-law index for the galaxies are different indicating perhaps that the galaxy environment may be playing a part in their origin and nature.

  18. Black silicon-based infrared radiation source

    Science.gov (United States)

    Anwar, Momen; Sabry, Yasser; Basset, Philippe; Marty, Frédéric; Bourouina, Tarik; Khalil, Diaa

    2016-03-01

    Micromachined infrared sources are enabling component for interferometric and spectroscopic sensors. Their compact size and low cost transform bulky instruments to the sensor scale, which is needed for a wide range of applications in the conventional and unconventional environments. The silicon micromachined sources should be engineered to have good emissivity across a large wavelength range because the intrinsic emissivity of silicon is low. This optimization was reported in literature by either the deposition of black metal at the surface of an emitter or the use of deep phonic crystal cavities, which complicates the fabrication technology and results in sharp dip lines in the spectral emissivity, respectively. In this work we report a micromachined infrared radiation source based on a heater on the top of black silicon structure for the first time in the literature, up to the authors' knowledge. The temperature of the device is characterized versus the applied voltage and the radiated spectrum is captured in the 1300 nm to 2500 nm spectral range; limited by the spectrum analysis instrument. The reported source opens the doors for completely integrated MEMS spectral sensors onchip.

  19. The natural sources of ionizing radiation exposure

    International Nuclear Information System (INIS)

    Maximilien, R.

    1982-01-01

    Natural sources of ionizing radiation include external sources (cosmic rays, natural radionuclides present in the crust of the earth and in building materials) and internal sources (naturally occuring radionuclides in the human body, especially the potassium 40 and radon short lived decay products). The principal ways of human exposure to theses different components in ''normal'' areas are reviewed; some examples of the variability of exposure with respect to different regions of the world or the habits of life are given. Actual estimations of the doses delivered to the organs are presented; for the main contributors to population exposure, the conversion into effective dose equivalent has been made for allowing a better evaluation of their respective importance [fr

  20. Localization of Point Sources for Poisson Equation using State Observers

    KAUST Repository

    Majeed, Muhammad Usman

    2016-08-09

    A method based On iterative observer design is presented to solve point source localization problem for Poisson equation with riven boundary data. The procedure involves solution of multiple boundary estimation sub problems using the available Dirichlet and Neumann data from different parts of the boundary. A weighted sum of these solution profiles of sub-problems localizes point sources inside the domain. Method to compute these weights is also provided. Numerical results are presented using finite differences in a rectangular domain. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

  1. Undulators as sources of synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Krinsky, S.

    1983-01-01

    At the present time the first generation of facilities having electron storage rings designed for and dedicated to synchrotron radiation research are beginning operations in the US, Europe and Japan. The use of wigglers and undulators as enhanced sources of synchrotron radiation plays an important role at all these facilities. Moreover, recently there has been much activity in the design of the next generation machines, which will place even greater, and perhaps exclusive, emphasis on the use of wigglers and undulators. The operation of these insertion devices has been made even more attractive by advances in the design and construction of permanent magnet wigglers and undulators. This reliable and economical technology eliminates the need for more complex superconducting magnets, except to achieve very high magnetic fields for the production of hard photons from relatively low energy rings. We review the spectral properties of the radiation, emphasizing the complementary aspects of time- and frequency-domain analyses. We next study the brightness of the undulator source. Finally, we consider some limitations associated with operating an undulator in a storage ring.

  2. Search for high energy cosmic neutrino point sources with ANTARES

    International Nuclear Information System (INIS)

    Halladjian, G.

    2010-01-01

    The aim of this thesis is the search for high energy cosmic neutrinos emitted by point sources with the ANTARES neutrino telescope. The detection of high energy cosmic neutrinos can bring answers to important questions such as the origin of cosmic rays and the γ-rays emission processes. In the first part of the thesis, the neutrino flux emitted by galactic and extragalactic sources and the number of events which can be detected by ANTARES are estimated. This study uses the measured γ-ray spectra of known sources taking into account the γ-ray absorption by the extragalactic background light. In the second part of the thesis, the absolute pointing of the ANTARES telescope is evaluated. Being located at a depth of 2475 m in sea water, the orientation of the detector is determined by an acoustic positioning system which relies on low and high frequency acoustic waves measurements between the sea surface and the bottom. The third part of the thesis is a search for neutrino point sources in the ANTARES data. The search algorithm is based on a likelihood ratio maximization method. It is used in two search strategies; 'the candidate sources list strategy' and 'the all sky search strategy'. Analysing 2007+2008 data, no discovery is made and the world's best upper limits on neutrino fluxes from various sources in the Southern sky are established. (author)

  3. Study of spear as a dedicated source of synchrotron radiation

    International Nuclear Information System (INIS)

    Cerino, J.; Golde, A.; Hastings, J.; Lindau, I.; Salsburg, B.; Winick, H.; Lee, M.; Morton, P.; Garren, A.

    1977-11-01

    A study was made of the potential of SPEAR as a dedicated source of synchrotron radiation, based on the expectation that SPEAR will become increasingly available for this purpose as PEP, the 18-GeV colliding-beam storage ring now under construction by LBL and SLAC, becomes operational. A synchrotron radiation research program has been underway since May, 1974. Two beam ports capable of serving 9 simultaneous users are now operational. In single-beam multi-bunch operation high currents are possible (225 mA has been achieved and > approximately 300 mA is expected) and the electron beam emittance can be made smaller, resulting in higher source point brightness. Descriptions are given of SPEAR capabilities and of plans to expand the research capability by adding beam runs and by inserting wiggler magnets in SPEAR straight sections

  4. Development of Reactor RIs and Radiation Sources

    International Nuclear Information System (INIS)

    Park, Ul Jae; Han, H. S.; Lee, J. S.

    2010-04-01

    This project aimed to develop radioisotopes and radiation sources, which are employed radiotherapy in medical fields and process diagnoses and measurements in industry. Major accomplishments are as followed. · Development of Non-Carrier-Added Therapeutic RI's - Developed the core separation processes by using novel adsorbents - Succeeded commercial scale production of non-carrier-added 177 Lu and developed production processes for 147 Pm and 47 Sc · Demonstration of 188 W/ 188 Re generator technology and prototype product - Demonstrated 1 Ci generator (30 times better performance than commercial products) - Developed pilot-scale production system, and supplied generators for the development of radiopharmaceuticals · Development of 90 Sr/ 90 Y Generator System - Developed core adsorbents for the RI separation - Constructed Proto type generator and demonstrated for 500mCi production - Demonstrated the production of radiopharmaceutical grade 90 Y : 100 ∼ 10,000 purer than commercially available products - Constructed pilot scale generator system for regular production of 90 Y ·Development of β-ray sources for thickness measurements and brachytherapy - Developed 90 Sr thickness gauge source and received KOLAS certification - Developed and tested for the possibility of the application of a β-ray source to brachytherapy of eye diseases. - Completed safety accessment of the P-32brachytherapy source ·Development of Small Focal γ-ray Source for Radiography - Developed the source and tested in real conditions: 28.5% improvement in radiography quality compared to a regular source - Technology-transferred for earlier commercialization ·Extraction of RI Mixture from Irradiated Natural Uranium without Dissolution - Multi-step separation of fission products for useful RI's - Developed six adsorbents and tested for the separation of Lanthanides and Actinide

  5. Reconstruction analysis of the IRAS Point Source Catalog Redshift Survey

    NARCIS (Netherlands)

    Narayanan, VK; Weinberg, DH; Branchini, E; Frenk, CS; Maddox, S; Oliver, S; Rowan-Robinson, M; Saunders, W

    We present the results of reconstruction analysis of the galaxy distribution in a spherical region of radius 50 h(-1) Mpc centered on the Local Group, as mapped by the IRAS Point Source Catalog Redshift Survey (PSCz). We reconstruct this galaxy distribution using 15 different models for structure

  6. Effect of point source and heterogeneity on the propagation of ...

    African Journals Online (AJOL)

    user

    This paper stands to investigate the possibility of propagation of SH waves due to a point source in a magnetoelastic monoclinic layer lying over a heterogeneous monoclinic half-space. The heterogeneity is caused by consideration of quadratic variation in rigidity. The methodology employed combines an efficient ...

  7. A Search for Point Sources of EeV Photons

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, A. J.; Matthews, J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pe¸kala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Peters, C.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Thao, N. T.; Theodoro, V. M.; Tiffenberg, J.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Whelan, B. J.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Auger Collaboration102, The Pierre

    2014-01-01

    Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic

  8. Assessment of the impact of point source pollution from the ...

    African Journals Online (AJOL)

    KSTP), was assessed in terms of pH, conductivity, and COD and nutrients removal from the influent. The contributions from this and other smaller point sources in the town to these parameters in the receiving Keiskamma River were determined by ...

  9. Determining and modeling the dispersion of non point source ...

    African Journals Online (AJOL)

    EJIRO

    Lake Victoria is an important source of livelihood that is threatened by rising pollution. In this study, pollutants in runoff are characterized and their dispersion after they enter the lake is measured and modeled at different points in the study areas. The objective is to develop a one dimensional mathematical model which can ...

  10. Ionizing radiation source detection by personal TLD

    International Nuclear Information System (INIS)

    Marinkovic, O.; Mirkov, Z.

    2002-01-01

    The Laboratory for personal dosimetry has about 3000 workers under control. The most of them work in medicine. Some institutions, as big health centers, have different ionizing radiation sources. It is usefull to analyze what has been the source of irradiation, special when appears a dosimeter with high dose. Personal dosimetry equipment is Harshaw TLD Reader Model 6600 and dosimeters consist of two chips LiF TLD-100 assembled in bar-coded cards which are wearing in holders with one tissue-equivalent filter (to determine H(10)) and skin-equivalent the other (to determine H(0.07)). The calibration dosimeters have been irradiated in holders by different sources: x-ray (for 80keV and 100keV), 6 0C o, 9 0S r (for different distances from beta source) and foton beem (at radiotherapy accelerator by 6MeV, 10MeV and 18MeV). The dose ratio for two LiF cristals was calculated and represented with graphs. So, it is possible to calculate the ratio H(10)/H(0.07) for a personal TLD and analyze what has been the source of irradiation. Also, there is the calibration for determination the time of irradiation, according to glow curve deconvolution

  11. Applications of Indus-1 synchrotron radiation source

    International Nuclear Information System (INIS)

    Nandedkar, R.V.

    2003-01-01

    Indus-1 is a 450 MeV electron storage ring. This is a soft X-ray and Vacuum Ultra Violet radiation source with the critical wavelength being 61 A. In this source, the first beam was stored in mid-1999 and was then made available, after initial storage and beam cleaning of the vacuum components, for beamline installation in the early 2000. Two beamlines are commissioned and are working. Other beamlines are in the advanced stage of commissioning. For Indus-1, the injection system consists of a 20 MeV classical microtron as a preinjector and a booster synchrotron that can go up to 700 MeV. For Indus-1, the injection into the storage ring is at full 450 MeV from this booster synchrotron

  12. Radiation sources safety and radioactive materials security regulation in Ukraine

    International Nuclear Information System (INIS)

    Smyshliaiev, A.; Holubiev, V.; Makarovska, O.

    2001-01-01

    Radiation sources are widely used in Ukraine. There are about 2500 users in industry, science, education and about 2800 in medicine. About 80,000 sealed radiation sources with total kerma-equivalent of 450 Gy*M 2 /sec are used in Ukraine. The exact information about the radiation sources and their users will be provided in 2001 after the expected completion of the State inventory of radiation sources in Ukraine. In order to ensure radiation source safety in Ukraine, a State System for regulation of activities dealing with radiation sources has been established. The system includes the following elements: establishment of norms, rules and standards of radiation safety; authorization activity, i.e. issuance of permits (including those in the form of licences) for activities dealing with radiation sources; supervisory activity, i.e. control over observance of norms, rules and standards of radiation safety and fulfilment of conditions of licences for activities dealing with radiation sources, and also enforcement. Comprehensive nuclear legislation was developed and implemented from 1991 to 2000. Radiation source safety is regulated by three main nuclear laws in Ukraine: On the use of nuclear energy and radiation safety (passed on 8 February 1995); On Human Protection from Impact of Ionizing Radiation (passed on 14 January 1998); On permissive activity in the area of nuclear energy utilization (passed on 11 January 2000). The regulatory authorities in Ukraine are the Ministry for Ecology and Natural Resources (Nuclear Regulatory Department) and the Ministry of Health (State sanitary-epidemiology supervision). According to the legislation, activities dealing with radiation sources are forbidden without an officially issued permit in Ukraine. Permitted activities with radiation sources are envisaged: licensing of production, storage and maintenance of radiation sources; licensing of the use of radiation sources; obligatory certification of radiation sources and transport

  13. Regulatory Control of Radiation Sources. Safety Guide

    International Nuclear Information System (INIS)

    2009-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  14. Effect of trigger point injection on lumbosacral radiculopathy source.

    Science.gov (United States)

    Saeidian, Seyed Reza; Pipelzadeh, Mohammad Reza; Rasras, Saleh; Zeinali, Masud

    2014-10-01

    Active muscular trigger points (aMTPs) presenting with radiating pain can interfere in diagnosis and treatment of patients suffering from lumbosacral radiculopathy. We aimed to diagnose and evaluate the trigger point therapy on the outcome of pain in patients with lumbosacral radiculopathy. A total of 98 patients were enrolled suffered with chronic pain andlumbosacral radiculopathy at L4-L5 and L5-S1 who were candidates of non-surgical management. All patients received conservative modalities, including bed rest, non-steroidal anti-inflammatory agents (NSAID), and physiotherapy. These treatments continued for a week. Patients were examined for the presence of trigger points in their lower extremities. Those who had trigger points were divided into 2 groups (TP and N). Patients in TP group underwent trigger point injection therapy. No further therapy was done for the N group. Pain scores and straight leg raise (SLR) test in both groups were collected and analyzed on the seventh and 10th days of the therapy. Results were analyzed by paired t test and chi-square test. Out of 98 patients, 64 had trigger points. Thirty-two patients were assigned to each group. Pain scores (Mean ± SD) in TP group was 7.12 ± 1.13 and in N group was 6.7 ± 1.16, P = 0.196. Following the treatment, pain scores were 2.4 ± 1.5 in TP group and 4.06 ± 1.76 in N group P = 0.008. SLR test became negative in all patients in TP group but only in 6 (19%) patients in N group, P = 0.001. Results show that trigger point injection therapy in patients suffering from chronic lumbosacral radiculopathy with trigger points can significantly improve their recovery, and conservative therapy may not be adequate.

  15. Radiation doses from radiation sources of neutrons and photons by different computer calculation

    International Nuclear Information System (INIS)

    Siciliano, F.; Lippolis, G.; Bruno, S.G.

    1995-12-01

    In the present paper the calculation technique aspects of dose rate from neutron and photon radiation sources are covered with reference both to the basic theoretical modeling of the MERCURE-4, XSDRNPM-S and MCNP-3A codes and from practical point of view performing safety analyses of irradiation risk of two transportation casks. The input data set of these calculations -regarding the CEN 10/200 HLW container and dry PWR spent fuel assemblies shipping cask- is frequently commented as for as connecting points of input data and understanding theoric background are concerned

  16. Transient point source analyses in the ANTARES neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Losa, Agustín, E-mail: Agustin.Sanchez@ific.uv.es

    2014-04-01

    The ANTARES telescope, with a duty cycle close to unity and a full hemisphere of the sky at all the times visible, is well suited to detect neutrinos produced in astrophysical transient sources. Assuming a known neutrino production period, the background and the sensitivity can be drastically improved by selecting a narrow time window around it. GRBs, μ-quasars and AGNs are particularly attractive potential neutrino point sources since neutrinos and gamma-rays may be produced in hadronic interactions with the surrounding medium as they are the most likely sources of the observed ultra high energy cosmic rays. A strong correlation between the gamma-ray and the neutrino fluxes is expected in this scenario. ANTARES data has been analyzed in various transient source analyses with the goal of detecting cosmic neutrinos from GRBs, μ-quasars and AGNs. The sensitivity of a standard time-integrated point source search can be improved by a factor 2–3 by looking for neutrinos only during the most probable emission time. This information can be provided by the different satellite telescope types on the X-rays and γ-rays wavelengths. The results of these different analyses will be presented.

  17. Point sources and multipoles in inverse scattering theory

    CERN Document Server

    Potthast, Roland

    2001-01-01

    Over the last twenty years, the growing availability of computing power has had an enormous impact on the classical fields of direct and inverse scattering. The study of inverse scattering, in particular, has developed rapidly with the ability to perform computational simulations of scattering processes and led to remarkable advances in a range of applications, from medical imaging and radar to remote sensing and seismic exploration. Point Sources and Multipoles in Inverse Scattering Theory provides a survey of recent developments in inverse acoustic and electromagnetic scattering theory. Focusing on methods developed over the last six years by Colton, Kirsch, and the author, this treatment uses point sources combined with several far-reaching techniques to obtain qualitative reconstruction methods. The author addresses questions of uniqueness, stability, and reconstructions for both two-and three-dimensional problems.With interest in extracting information about an object through scattered waves at an all-ti...

  18. Is a wind turbine a point source? (L).

    Science.gov (United States)

    Makarewicz, Rufin

    2011-02-01

    Measurements show that practically all noise of wind turbine noise is produced by turbine blades, sometimes a few tens of meters long, despite that the model of a point source located at the hub height is commonly used. The plane of rotating blades is the critical location of the receiver because the distances to the blades are the shortest. It is shown that such location requires certain condition to be met. The model is valid far away from the wind turbine as well.

  19. Reduction Assessment of Agricultural Non-Point Source Pollutant Loading

    OpenAIRE

    Fu, YiCheng; Zang, Wenbin; Zhang, Jian; Wang, Hongtao; Zhang, Chunling; Shi, Wanli

    2018-01-01

    NPS (Non-point source) pollution has become a key impact element to watershed environment at present. With the development of technology, application of models to control NPS pollution has become a very common practice for resource management and Pollutant reduction control in the watershed scale of China. The SWAT (Soil and Water Assessment Tool) model is a semi-conceptual model, which was put forward to estimate pollutant production & the influences on water quantity-quality under different...

  20. Diffusion from a point source in an urban atmosphere

    International Nuclear Information System (INIS)

    Essa, K.S.M.; El-Otaify, M.S.

    2005-01-01

    In the present paper, a model for the diffusion of material from a point source in an urban atmosphere is incorporated. The plume is assumed to have a well-defined edge at which the concentration falls to zero. The vertical wind shear is estimated using logarithmic law, by employing most of the available techniques of stability categories. The concentrations estimated from the model were compared favorably with the field observations of other investigators

  1. Low frequency interference between short synchrotron radiation sources

    Directory of Open Access Journals (Sweden)

    F. Méot

    2001-06-01

    Full Text Available A recently developed analytical formalism describing low frequency far-field synchrotron radiation (SR is applied to the calculation of spectral angular radiation densities from interfering short sources (edge, short magnet. This is illustrated by analytical calculation of synchrotron radiation from various assemblies of short dipoles, including an “isolated” highest density infrared SR source.

  2. A new radiation source: the 'CASSITRON'

    International Nuclear Information System (INIS)

    Sadat, T.; Aucouturier, J.

    1984-01-01

    The CASSITRON, a radiation source conceived and made by CGR MeV, is intended for food processing, the sterilization of disposable medical supplies, sludge sterilization, and the treatment of polymers and chemical products. Its physical characteristics are described. Also the industrial characteristics, i.e. security, simplicity, reliability, easy insertion in a production line system and multipurpose use are explained. Meeting the physical, industrial and economic needs, the CASSITRON is a secure, reliable and simple electric machine. It is a multipurpose accelerator, and can be easily inserted in a production line system. The machine is composed mainly of an electron generator, a modulator, a conversion-device to produce hard x-ray with the electron beam, and a control console. (Mori, K.)

  3. Cesium-137 as a radiation source

    International Nuclear Information System (INIS)

    McMullen, W.H.; Sloan, D.P.

    1985-01-01

    The U.S. Department of Energy (DOE) Byproducts Utilization Program (BUP) seeks to develop and encourage widespread commercial use of defense byproducts that are produced by DOE. Cesium-l37 is one such byproduct that is radioactive and decays with emission of gamma rays. The beneficial use of this radiation to disinfect sewage sludge or disinfest food commodities is actively being pursued by the program. The radiation produced by cesium-l37(Cs-l37) is identical in form to that produced by cobalt-60(Co-60), an isotope that is widely used in commercial applications such as medical product sterilization. The choice of isotope to use depends on several factors ranging from inherent properties of the isotopes to availability and cost. The BUP, although centrally concerned with the beneficial use of Cs-l37, by investigating and assessing the feasibility of various uses hopes to define appropriate circumstances where cesium or cobalt might best be used to accomplish specific objectives. This paper discusses some of the factors that should be considered when evaluating potential uses for isotopic sources

  4. An industrial radiation source for food processing

    International Nuclear Information System (INIS)

    Sadat, R.

    1986-01-01

    The scientific linacs realized by CGR MeV in France have been installed in several research centers, the medical accelerators of CGR MeV have been installed in radiotherapy centers all over the world, and the industrial linacs have been used for radiography in heavy industries. Based on the experience for 30 years, CGR MeV has realized a new industrial radiation source for food processing. CARIC is going to install a new machine of CGR MeV, CASSITRON, as the demand for radiation increased. This machine has been devised specially for industrial irradiation purpose. Its main features are security, simplicity and reliability, and it is easy to incorporate it into a production line. The use of CASSITRON for food industry, the ionizing effect on mechanically separated poultry meat, the capital and processing cost and others are explained. Only 10 % of medical disposable supplies is treated by ionizing energy in France. The irradiation for food decontamination, and that for industrial treatment are demanded. Therefore, CARIC is going to increase the capacity by installing a CASSITRON for sterilization. The capital and processing cost are shown. The start of operation is expected in March, 1986. At present, a CASSITRON is being installed in the SPI food processing factory, and starts operation in a few weeks. (Kako, I.)

  5. Study on the piezoresistivity of radiation-induced point defects

    International Nuclear Information System (INIS)

    Cochard, Andre.

    1976-06-01

    This study is made of two distinct part. In a first part experimental results on the elastoresistivity of radiation-induced point defects in gold are presented. A comparison with the results on copper and molybdenum confirms the exceptional annealing behavior of gold. However, as for copper, only interstitials contribute to elastoresistivity. The results can be understood if the elastoresistivity on gold is associated to Frenkel defects. In a second part an experimental set up is described allowing the dynamic measurement of the piezoresistivity associated to radiation-induced point defects. Experiments were carried out on pure copper and Al-Cu alloys. It is shown that both, the modulus and the phase angle of the complex piezoresistivity have to be measured simultaneously. The thermoelastic effect, a phenomenon due to temperature changes in the sample under rapidly varying strain was studied as a function of strain amplitude and frequency. A simple theory of this effect yields a correct description of the experimental results [fr

  6. Storing strong spent ionizing-radiation sources in metal matrices

    International Nuclear Information System (INIS)

    Sobolev, I.A.; Arustamov, A.E.; Ozhovan, M.I.; Poluektov, P.P.; Polyakov, A.S.; Semenov, K.N.; Timofeev, E.M.; Tret'yak, S.A.; Shiryaev, V.V.

    1989-01-01

    The Moscow Radon Cooperative has collaborated with the Bochvar Research Institute since 1986 in a new method of handling spent sources for placing in undergound stores. The spent sources are mounted in metal matrices. Each batch of sources after discharge from the containers is enclosed in a layer of metal. This produces firstly uniform activity distribution, which reduces the radiation and thermal loads, and secondly isolates the sources reliably from the environment. Metals are used for the matrices because of the high activity, as metals have good radiation stability and adequate corrosion resistance, while providing good cooling and preventing local overheating. The best matrices are based on lead alloys, which have low melting points, low corrosion rates, low cost, and general availability. Calculations and experience show that the lead consumption is very low and constitutes only 1.35 x 10 -14 cm 3 · Bq -1 (5 x 10 -4 dm 3 ·Ci -1 for 60 Co). The equipment and storage method is described

  7. Interference between source-free radiation and radiation from sources: Particle-like behavior for classical radiation

    Science.gov (United States)

    Boyer, Timothy H.

    2017-09-01

    A simple junior-level electrodynamics problem is used to illustrate the interference between a source-free standing plane wave and a wave generated by a pulse in a current sheet. Depending upon the relative phases between the standing wave and the current pulse and also upon the relative magnitudes, we can find quite different patterns of emitted energy and momentum. If the source gives a large radiation pulse so that the source-free plane wave can be neglected, then the radiation spreads out symmetrically on either side of the current sheet. However, if the radiation sheet gives a pulse with fields comparable to those of the standing wave, then we can find a single radiation pulse moving to the right while the current sheet recoils to the left or the situation with the directions reversed. The example is a crude illustration of particle-like behavior arising from conventional classical electromagnetic behavior in the presence of source-free radiation. The discussion makes contact with the ideas of photons in modern physics.

  8. Scattering and absorption of particles emitted by a point source in a cluster of point scatterers

    International Nuclear Information System (INIS)

    Liljequist, D.

    2012-01-01

    A theory for the scattering and absorption of particles isotropically emitted by a point source in a cluster of point scatterers is described and related to the theory for the scattering of an incident particle beam. The quantum mechanical probability of escape from the cluster in different directions is calculated, as well as the spatial distribution of absorption events within the cluster. A source strength renormalization procedure is required. The average quantum scattering in clusters with randomly shifting scatterer positions is compared to trajectory simulation with the aim of studying the validity of the trajectory method. Differences between the results of the quantum and trajectory methods are found primarily for wavelengths larger than the average distance between nearest neighbour scatterers. The average quantum results include, for example, a local minimum in the number of absorption events at the location of the point source and interference patterns in the angle-dependent escape probability as well as in the distribution of absorption events. The relative error of the trajectory method is in general, though not generally, of similar magnitude as that obtained for beam scattering.

  9. Methods to identify and locate spent radiation sources

    International Nuclear Information System (INIS)

    1995-07-01

    The objective of this manual is to provide essential guidance to Member States with nuclear applications involving the use of a wide range of sealed radiation sources on the practical task of physically locating spent radiation sources not properly accounted for. Advice is also provided to render the located source safe on location. Refs, figs and tabs

  10. Methods to identify and locate spent radiation sources

    International Nuclear Information System (INIS)

    1997-06-01

    The objective of this manual is to provide essential guidance to Member States with nuclear applications involving the use of a wide range of sealed radiation sources on the practical task of physically locating spent radiation sources not properly accounted for. Advice is also provided to render the located source safe on location. Refs, figs, tabs

  11. The regulatory control of radiation sources in Turkey

    International Nuclear Information System (INIS)

    Uslu, I.; Birol, E.

    2001-01-01

    In Turkey, the national competent authority for regulating activities involving radioactive sources is the Turkish Atomic Energy Authority, which implements the responsibility for the safety and security of radiation sources through its Radiation Health and Safety Department. The report describes the organization of the regulatory infrastructure for radiation safety in Turkey and, after a brief explanation of the current legal framework for such purpose, it refers to how the management of radiation sources is carried out and to the new provisions regarding radiation sources, including inspections of licensees and training on source safety. Finally, the report provides information on the Ikitelli radiological accident in Turkey and the current public concern about radiation sources after it happened. (author)

  12. A search for point sources of EeV photons

    Energy Technology Data Exchange (ETDEWEB)

    Aab, A. [Universität Siegen, Siegen (Germany); Abreu, P.; Andringa, S. [Laboratório de Instrumentação e Física Experimental de Partículas (LIP) and Instituto Superior Técnico (IST), Universidade de Lisboa (Portugal); Aglietta, M. [Osservatorio Astrofisico di Torino (INAF), Università di Torino and Sezione INFN, Torino (Italy); Ahlers, M. [University of Wisconsin, Madison, WI (United States); Ahn, E. J. [Fermilab, Batavia, IL (United States); Al Samarai, I. [Institut de Physique Nucléaire d' Orsay (IPNO), Université Paris 11, CNRS-IN2P3, Orsay (France); Albuquerque, I. F. M. [Universidade de São Paulo, Instituto de Física, São Paulo, SP (Brazil); Allekotte, I. [Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Allen, J. [New York University, New York, NY (United States); Allison, P. [Ohio State University, Columbus, OH (United States); Almela, A. [Universidad Tecnológica Nacional—Facultad Regional Buenos Aires, Buenos Aires (Argentina); Castillo, J. Alvarez [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico); Alvarez-Muñiz, J. [Universidad de Santiago de Compostela (Spain); Batista, R. Alves [Universität Hamburg, Hamburg (Germany); Ambrosio, M.; Aramo, C. [Università di Napoli " Federico II" and Sezione INFN, Napoli (Italy); Aminaei, A. [IMAPP, Radboud University Nijmegen (Netherlands); Anchordoqui, L. [University of Wisconsin, Milwaukee, WI (United States); Arqueros, F. [Universidad Complutense de Madrid, Madrid (Spain); Collaboration: Pierre Auger Collaboration102; and others

    2014-07-10

    Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from –85° to +20°, in an energy range from 10{sup 17.3} eV to 10{sup 18.5} eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of –2, is 0.06 eV cm{sup –2} s{sup –1}, and no celestial direction exceeds 0.25 eV cm{sup –2} s{sup –1}. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.

  13. Open-Source Automated Mapping Four-Point Probe.

    Science.gov (United States)

    Chandra, Handy; Allen, Spencer W; Oberloier, Shane W; Bihari, Nupur; Gwamuri, Jephias; Pearce, Joshua M

    2017-01-26

    Scientists have begun using self-replicating rapid prototyper (RepRap) 3-D printers to manufacture open source digital designs of scientific equipment. This approach is refined here to develop a novel instrument capable of performing automated large-area four-point probe measurements. The designs for conversion of a RepRap 3-D printer to a 2-D open source four-point probe (OS4PP) measurement device are detailed for the mechanical and electrical systems. Free and open source software and firmware are developed to operate the tool. The OS4PP was validated against a wide range of discrete resistors and indium tin oxide (ITO) samples of different thicknesses both pre- and post-annealing. The OS4PP was then compared to two commercial proprietary systems. Results of resistors from 10 to 1 MΩ show errors of less than 1% for the OS4PP. The 3-D mapping of sheet resistance of ITO samples successfully demonstrated the automated capability to measure non-uniformities in large-area samples. The results indicate that all measured values are within the same order of magnitude when compared to two proprietary measurement systems. In conclusion, the OS4PP system, which costs less than 70% of manual proprietary systems, is comparable electrically while offering automated 100 micron positional accuracy for measuring sheet resistance over larger areas.

  14. Open-Source Automated Mapping Four-Point Probe

    Directory of Open Access Journals (Sweden)

    Handy Chandra

    2017-01-01

    Full Text Available Scientists have begun using self-replicating rapid prototyper (RepRap 3-D printers to manufacture open source digital designs of scientific equipment. This approach is refined here to develop a novel instrument capable of performing automated large-area four-point probe measurements. The designs for conversion of a RepRap 3-D printer to a 2-D open source four-point probe (OS4PP measurement device are detailed for the mechanical and electrical systems. Free and open source software and firmware are developed to operate the tool. The OS4PP was validated against a wide range of discrete resistors and indium tin oxide (ITO samples of different thicknesses both pre- and post-annealing. The OS4PP was then compared to two commercial proprietary systems. Results of resistors from 10 to 1 MΩ show errors of less than 1% for the OS4PP. The 3-D mapping of sheet resistance of ITO samples successfully demonstrated the automated capability to measure non-uniformities in large-area samples. The results indicate that all measured values are within the same order of magnitude when compared to two proprietary measurement systems. In conclusion, the OS4PP system, which costs less than 70% of manual proprietary systems, is comparable electrically while offering automated 100 micron positional accuracy for measuring sheet resistance over larger areas.

  15. The Vacuum Spark VSX-200 as a Soft X-Ray Point Source for Laboratory Microlithography

    Science.gov (United States)

    Panarella, Emilio

    2001-10-01

    The technology of X-ray point plasma sources is taking over the role that previously was retained by the multiple beam synchrotrons as radiation source for submicron lithography. A Plasma Point Source System (VSX 200) has been designed by our company ALFT as an entrance tool for Universities and other Research Laboratories working in the field of semiconductors. Because the radiation is emitted in small dose in each spark, it is necessary to repeat the phenomenon at high frequency in order to have a quasi-continuous wave. The soft X-ray power distribution is uniform, thus meeting the requirement for microlithography. The output of the VSX 200 is 200 mW of 0.93 keV radiation ( ~14 angstroms) in the copper line emitted continuously and reliably. Our plan is to increase the power level to 2 W for a low volume market that requires performance of 1 Wafer Layer per Hour (WLPH) or less, and then scale the device to eventually reach the silicon market that requires 20 WLPH. We expect to be able to support R&D and low volume applications such as Military Communication GaAs Chips by year-end. A demonstration system will be available in California at that time.

  16. Low-energy point source searches with IceCube

    Directory of Open Access Journals (Sweden)

    Euler Sebastian

    2016-01-01

    Full Text Available Due to the overwhelming background of atmospheric muons, the traditional IceCube point source search in the Southern Hemisphere is mainly sensitive to neutrinos with energies above 100TeV. A new approach focuses on events starting inside the instrumented volume. By utilizing different veto techniques we are able to significantly reduce the energy threshold and can now for the first time explore the entire Southern Hemisphere at neutrino energies as low as 100GeV. We present the results of two analyses targeting slightly different energy ranges. Both use one year of data taken with the completed IceCube detector in 2011/12.

  17. [Use of ionizing radiation sources in metallurgy: risk assessment].

    Science.gov (United States)

    Giugni, U

    2012-01-01

    Use of ionizing radiation sources in the metallurgical industry: risk assessment. Radioactive sources and fixed or mobile X-ray equipment are used for both process and quality control. The use of ionizing radiation sources requires careful risk assessment. The text lists the characteristics of the sources and the legal requirements, and contains a description of the documentation required and the methods used for risk assessment. It describes how to estimate the doses to operators and the relevant classification criteria used for the purpose of radiation protection. Training programs must be organized in close collaboration between the radiation protection expert and the occupational physician.

  18. Exposition index calculation from different points in a gamma sterilization plant radiation room

    International Nuclear Information System (INIS)

    Carrasco, A.H.

    1983-01-01

    Radiation fields produced by a JS-6500 rectangular irradiator source were evaluated. Knowledge of the values of these fields is necessary in irradiation and health physics processes. Techniques for evaluating the dose rates from puntual, linear and plane sources were applied and computer programs for the three sources designed. Fricke, cupric-ferrous and red acrilic dosimetric systems were used, to verify the eight points located along the interior walls of the irradiation room, around the source with 936, 987 Ci of Co-60 (1st-March 1980). When considering the distance between the source and each point of interest the calculated exposition indexes obtained were practically the same for the three source types and were up to 35% greater than the experimental values; in contrast when absorption and buildup of the source were taken in to account, the experimental values were higher than the calculated ones by up to 16%, this in estimating the produced exposition index for a rectangular source at least there two parameters should be included. (author)

  19. Preparation of very small point sources for high resolution radiography

    International Nuclear Information System (INIS)

    Case, F.N.

    1976-01-01

    The need for very small point sources of high specific activity 192 Ir, 169 Yb, 170 Tm, and 60 Co in non-destructive testing has motivated the development of techniques for the fabrication of these sources. To prepare 192 Ir point sources for use in examination of tube sheet welds in LMFBR heat exchangers, 191 Ir enriched to greater than 90 percent was melted in a helium blanketed arc to form spheres as small as 0.38 mm in diameter. Methods were developed to form the roughly spherical shaped arc product into nearly symmetrical spheres that could be used for high resolution radiography. Similar methods were used for spherical shaped sources of 169 Yb and 170 Tm. The oxides were arc melted to form rough spheres followed by grinding to precise dimensions, neutron irradiation of the spheres at a flux of 2 to 3 x 10 15 nv, and use of enriched 168 Yb to provide the maximum specific activity. Cobalt-60 with a specific activity of greater than 1100 Ci/g was prepared by processing 59 Co that had been neutron irradiated to nearly complete burnup of the 59 Co target to produce 60 Co, 61 Ni, and 62 Ni. Ion exchange methods were used to separate the cobalt from the nickel. The cobalt was reduced to metal by plating either onto aluminum foil which was dissolved away from the cobalt plate, or by plating onto mercury to prepare amalgam that could be easily formed into a pellet of cobalt with exclusion of the mercury. Both methods are discussed

  20. Noncontact localized internal infrared radiation measurement using an infrared point detector

    Science.gov (United States)

    Hisaka, Masaki

    2017-12-01

    The techniques for temperature measurement within the human body are important for clinical applications. A method for noncontact local infrared (IR) radiation measurements was investigated deep within an object to simulate how the core human body temperature can be obtained. To isolate the IR light emitted from a specific area within the object from the external noise, the radiating IR light was detected using an IR point detector, which comprises a pinhole and a thermopile positioned at an imaging relation with the region of interest within the object. The structure of the helical filament radiating IR light inside a light bulb was thermally imaged by scanning the bulb in two dimensions. Moreover, this approach was used to effectively measure IR light in the range of human body temperature using a glass plate placed in front of the heat source, mimicking the ocular fundus.

  1. Radiological control in fires involving radiation sources

    International Nuclear Information System (INIS)

    Franco, J.O.A.; Coelho, C.P.

    1984-01-01

    The copies used during the chatter by techniques from CDTN in the I Mineiro Symposium of Fire Engineering, are presented. The chatter was based on emergency radiation control course, given by CDTN. Basic concepts, such as nuclear physics fundaments, radiation nature and detection, radiation protection and practical aspects of radiological fire emergency, were enphasized. (M.C.K.) [pt

  2. Scattering of point particles by black holes: Gravitational radiation

    Science.gov (United States)

    Hopper, Seth; Cardoso, Vitor

    2018-02-01

    Gravitational waves can teach us not only about sources and the environment where they were generated, but also about the gravitational interaction itself. Here we study the features of gravitational radiation produced during the scattering of a pointlike mass by a black hole. Our results are exact (to numerical error) at any order in a velocity expansion, and are compared against various approximations. At large impact parameter and relatively small velocities our results agree to within percent level with various post-Newtonian and weak-field results. Further, we find good agreement with scaling predictions in the weak-field/high-energy regime. Lastly, we achieve striking agreement with zero-frequency estimates.

  3. Nature and magnitude of the problem of spent radiation sources

    International Nuclear Information System (INIS)

    1991-09-01

    Various types of sealed radiation sources are widely used in industry, medicine and research. Virtually all countries have some sealed sources. The activity in the sources varies from kilobecquerels in consumer products to hundreds of pentabecquerels in facilities for food irradiation. Loss or misuse of sealed sources can give rise to accidents resulting in radiation exposure of workers and members of the general public, and can also give rise to extensive contamination of land, equipment and buildings. In extreme cases the exposure can be lethal. Problems of safety relating to spent radiation sources have been under consideration within the Agency for some years. The first objective of the project has been to prepare a comprehensive report reviewing the nature and background of the problem, also giving an overview of existing practices for the management of spent radiation sources. This report is the fulfilment of this first objective. The safe management of spent radiation sources cannot be studied in isolation from their normal use, so it has been necessary to include some details which are relevant to the use of radiation sources in general, although that area is outside the scope of this report. The report is limited to radiation sources made up of radioactive material. The Agency is implementing a comprehensive action plan for assistance to Member States, especially the developing countries, in all aspects of the safe management of spent radiation sources. The Agency is further seeking to establish regional or global solutions to the problems of long-term storage of spent radiation sources, as well as finding routes for the disposal of sources when it is not feasible to set up safe national solutions. The cost of remedial actions after an accident with radiation sources can be very high indeed: millions of dollars. If the Agency can help to prevent even one such single accident, the cost of its whole programme in this field would be more than covered. Refs

  4. Effect of tissue inhomogeneity on dose distribution of point sources of low-energy electrons

    International Nuclear Information System (INIS)

    Kwok, C.S.; Bialobzyski, P.J.; Yu, S.K.; Prestwich, W.V.

    1990-01-01

    Perturbation in dose distributions of point sources of low-energy electrons at planar interfaces of cortical bone (CB) and red marrow (RM) was investigated experimentally and by Monte Carlo codes EGS and the TIGER series. Ultrathin LiF thermoluminescent dosimeters were used to measure the dose distributions of point sources of 204 Tl and 147 Pm in RM. When the point sources were at 12 mg/cm 2 from a planar interface of CB and RM equivalent plastics, dose enhancement ratios in RM averaged over the region 0--12 mg/cm 2 from the interface were measured to be 1.08±0.03 (SE) and 1.03±0.03 (SE) for 204 Tl and 147 Pm, respectively. The Monte Carlo codes predicted 1.05±0.02 and 1.01±0.02 for the two nuclides, respectively. However, EGS gave consistently 3% higher dose in the dose scoring region than the TIGER series when point sources of monoenergetic electrons up to 0.75 MeV energy were considered in the homogeneous RM situation or in the CB and RM heterogeneous situation. By means of the TIGER series, it was demonstrated that aluminum, which is normally assumed to be equivalent to CB in radiation dosimetry, leads to an overestimation of backscattering of low-energy electrons in soft tissue at a CB--soft-tissue interface by as much as a factor of 2

  5. Radioactive point source localization in a bulky volume

    International Nuclear Information System (INIS)

    Presler, O.; German, U.; Alfassi, Z.B.

    2005-01-01

    When using two detectors to measure the emission of gamma rays from a bulky sample, the count rates ratio of the detectors can be used to locate a radioactive source in a bulky volume. This process may be needed for locating a source in a scrap or waste container. Simple functions for location determination can be developed for the non-absorbing and pure-absorbing media, but for the general case, a more sophisticated method must be used. A simple and practical algorithm was developed, which can predict the location of a point source in a bulk volume quite accurately, with an average possible deviation of up to about 1cm, except for extreme combinations of dimension and absorption coefficient, but also in this case the maximal expected deviations are not more than several centimeters. The algorithm was checked experimentally for several bulk volumes with length of up to about 50cm and with different length/absorption coefficient combinations. The experimental validation was performed for a great range of absorption coefficients (from μ=0.0001 to 0.2cm -1 ), covering the practical range of waste containers compositions

  6. Beta radiation field of a 85Kr source

    International Nuclear Information System (INIS)

    Caldas, L.V.E.; David, J.

    1987-12-01

    The beta radiation field of a 85 Kr(3,7GBq) source utilized in industrial applications was determined, with the use of gamagraphy films, a scintillation detector, an extrapolation chamber and thermoluminescent (TL) dosemeters of CaSO 4 : Tm. Among other characteristics, the isodose curves of beta radiation and Bremsstrahlung radiation were obtained experimentally. (author) [pt

  7. Natural radiation source fabricated from commercially available instant coffee

    International Nuclear Information System (INIS)

    Kawano, Takao; Ando, Yoshiaki; Izumi, Yuuichi

    2015-01-01

    Commercially available instant coffee, Nescafe Excella, contained the radionuclide 40 K. From the instant coffee, sixteen coffee-block radiation sources were successfully fabricated with sufficiently low production dependences. The coffee-block radiation sources were examined their suitability for a radiation protection course. Although a part of radiation counts(cpm) obtained with 1 minute measurement were largely deviated, those determined by 5 minute measurements and five times of 1 minute measurement were less deviated, enabling better comprehension of the three cardinal principles of radiation protection. (author)

  8. Protection in handling ionizing radiation sources in national economy

    International Nuclear Information System (INIS)

    1986-01-01

    The collection of study texts is divided into 13 chapters giving an explanation of the structure of the atom, the properties of ionizing radiation and its interactions, quantities and units used, basic dosimetric methods, biological radiation effects, the sources of population exposure, the principles of radiation protection, technological applications of ionizing radiation, the monitoring of personnel and environment, the method of recording and filing, the method of protection from external radiation and internal contamination, health care, and requirements for protection in handling nonsealed sources. (M.D.)

  9. Indirect detection of radiation sources through direct detection of radiolysis products

    Science.gov (United States)

    Farmer, Joseph C [Tracy, CA; Fischer, Larry E [Los Gatos, CA; Felter, Thomas E [Livermore, CA

    2010-04-20

    A system for indirectly detecting a radiation source by directly detecting radiolytic products. The radiation source emits radiation and the radiation produces the radiolytic products. A fluid is positioned to receive the radiation from the radiation source. When the fluid is irradiated, radiolytic products are produced. By directly detecting the radiolytic products, the radiation source is detected.

  10. The peak efficiency calibration of volume source using 152Eu point source in computer

    International Nuclear Information System (INIS)

    Shen Tingyun; Qian Jianfu; Nan Qinliang; Zhou Yanguo

    1997-01-01

    The author describes the method of the peak efficiency calibration of volume source by means of 152 Eu point source for HPGe γ spectrometer. The peak efficiency can be computed by Monte Carlo simulation, after inputting parameter of detector. The computation results are in agreement with the experimental results with an error of +-3.8%, with an exception one is about +-7.4%

  11. Safety of radiation sources and other radioactive materials in Jordan

    International Nuclear Information System (INIS)

    Majali, M.M.

    2001-01-01

    Since joining the IAEA Model Project for upgrading radiation protection infrastructure in countries of West Asia, Jordan has amended its radiation safety legislation. The Regulatory Authority is improving its inventory system for radiation sources and other radioactive materials and also its notification, registration, licensing, inspection and enforcement systems. It has established national provisions for the management of orphan sources after they have been found. The system for the control of the radiation sources and other radioactive materials entering the country has been improved by the Regulatory Authority. (author)

  12. Detailed observations of the source of terrestrial narrowband electromagnetic radiation

    Science.gov (United States)

    Kurth, W. S.

    1982-01-01

    Detailed observations are presented of a region near the terrestrial plasmapause where narrowband electromagnetic radiation (previously called escaping nonthermal continuum radiation) is being generated. These observations show a direct correspondence between the narrowband radio emissions and electron cyclotron harmonic waves near the upper hybrid resonance frequency. In addition, electromagnetic radiation propagating in the Z-mode is observed in the source region which provides an extremely accurate determination of the electron plasma frequency and, hence, density profile of the source region. The data strongly suggest that electrostatic waves and not Cerenkov radiation are the source of the banded radio emissions and define the coupling which must be described by any viable theory.

  13. 76 FR 6692 - Radiation Sources on Army Land

    Science.gov (United States)

    2011-02-08

    ... DEPARTMENT OF DEFENSE Department of the Army 32 CFR Part 655 [Docket No. USA-2008-0001] RIN 0702-AA58 Radiation Sources on Army Land AGENCY: Department of the Army, DoD. ACTION: Final rule. SUMMARY: The Department of the Army is finalizing revisions to its regulation concerning radiation sources on...

  14. Radiative forcing of iron oxides from combustion sources

    Science.gov (United States)

    Ito, A.; Lin, G.; Penner, J.

    2017-12-01

    Combustion aerosols affect the climate by absorbing and scattering radiation. Iron (Fe) oxides emitted from combustion sources largely reside in supermicron aerosols. Fe oxides on aerosols are known to absorb sun light and heat the atmosphere. However, supermicron aerosols from combustion sources are ignored for radiative forcing in climate models. Here, we use a global chemical transport model and a radiative transfer model to estimate the radiative forcing of Fe oxides from combustion sources. The model results suggest that Fe oxides from combustion sources significantly contribute to a warming effect at the top of the atmosphere over the air polluted regions such as China and India as well as biomass burning source regions. However, the estimates strongly depend on chemical speciation of Fe oxides, which is also important for bioavailability. These results suggest comprehensive observations are needed to fully understand the effects of Fe oxides on the net radiative forcing and ecosystems.

  15. A compiled catalog of rotation measures of radio point sources

    International Nuclear Information System (INIS)

    Xu Jun; Han Jin-Lin

    2014-01-01

    We compiled a catalog of Faraday rotation measures (RMs) for 4553 extragalactic radio point sources published in literature. These RMs were derived from multi-frequency polarization observations. The RM data are compared to those in the NRAO VLA Sky Survey (NVSS) RM catalog. We reveal a systematic uncertainty of about 10.0 ± 1.5 rad m −2 in the NVSS RM catalog. The Galactic foreground RM is calculated through a weighted averaging method by using the compiled RM catalog together with the NVSS RM catalog, with careful consideration of uncertainties in the RM data. The data from the catalog and the interface for the Galactic foreground RM calculations are publicly available on the webpage: http://zmtt.bao.ac.cn/RM/. (research papers)

  16. 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

  17. The safety of radiation sources and radioactive materials in China

    International Nuclear Information System (INIS)

    Liu, H.

    2001-01-01

    The report describes the present infrastructure for the safety of radiation sources in China, where applications of radiation sources have become more and more widespread in the past years. In particular, it refers to the main functions of the National Nuclear Safety Administration of the State Environmental Protection Administration (SEPA), which is acting as the regulatory body for nuclear and radiation safety at nuclear installations, the Ministry of Public Health which issues licences for the use of radiation sources, and the Ministry of Public Security, which deals with the security of radiation sources. The report also refers to the main requirements of the existing regulatory system for radiation safety, i.e. the basic dose limits for radiation workers and the public, the licensing system for nuclear installations and for radioisotope-based and other irradiation devices, and the environmental impact assessment system. Information on the nationwide survey of radiation sources carried out by SEPA in 1991 is provided, and on some accidents that occurred in China due to loss of control of radiation sources and errors in the operation of irradiation facilities. (author)

  18. Trans-Z-source and Γ-Z-source neutral-point-clamped inverters

    DEFF Research Database (Denmark)

    Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    Z-source neutral-point-clamped (NPC) inverters are earlier proposed for obtaining voltage buck-boost and three-level switching simultaneously. Their performances are, however, constrained by a trade-off between their input-to-output gain and modulation ratio. This trade-off can lead to high...

  19. 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...

  20. Power-Law Template for IR Point Source Clustering

    Science.gov (United States)

    Addison, Graeme E.; Dunkley, Joanna; Hajian, Amir; Viero, Marco; Bond, J. Richard; Das, Sudeep; Devlin, Mark; Halpern, Mark; Hincks, Adam; Hlozek, Renee; hide

    2011-01-01

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217,353,545 and 857 GHz, over angular scales 100 law of the form C_l\\propto I(sup -n) with n = 1.25 +/- 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, nu(sup beta) B(nu,T_eff), with a single emissivity index beta = 2.20 +/- 0.07 and effective temperature T_eff= 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be alpha_150-220 = 3.68 +/- 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in Cosmic Microwave Background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  1. Power-Law Template for Infrared Point-Source Clustering

    Science.gov (United States)

    Addison, Graeme E; Dunkley, Joanna; Hajian, Amir; Viero, Marco; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Halpern, Mark; Hincks, Adam D; Hlozek, Renee; hide

    2012-01-01

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217, 353, 545, and 857 GHz, over angular scales 100 approx law of the form C(sup clust)(sub l) varies as l (sub -n) with n = 1.25 +/- 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, ?(sup Beta)B(?, T(sub eff) ), with a single emissivity index Beta = 2.20 +/- 0.07 and effective temperature T(sub eff) = 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be alpha(sub 150-220) = 3.68 +/- 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in cosmic microwave background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  2. Random electrodynamics: the theory of classical electrodynamics with classical electromagnetic zero-point radiation

    International Nuclear Information System (INIS)

    Boyer, T.H.

    1975-01-01

    The theory of classical electrodynamics with classical electromagnetic zero-point radiation is outlined here under the title random electrodynamics. The work represents a reanalysis of the bounds of validity of classical electron theory which should sharpen the understanding of the connections and distinctions between classical and quantum theories. The new theory of random electrodynamics is a classical electron theory involving Newton's equations for particle motion due to the Lorentz force, and Maxwell's equations for the electromagnetic fields with point particles as sources. However, the theory departs from the classical electron theory of Lorentz in that it adopts a new boundary condition on Maxwell's equations. It is assumed that the homogeneous boundary condition involves random classical electromagnetic radiation with a Lorentz-invariant spectrum, classical electromagnetic zero-point radiation. The implications of random electrodynamics for atomic structure, atomic spectra, and particle-interference effects are discussed on an order-of-magnitude or heuristic level. Some detailed mathematical connections and some merely heuristic connections are noted between random electrodynamics and quantum theory. (U.S.)

  3. Large area radiation source for water and wastewater treatment

    Science.gov (United States)

    Mueller, Michael T.; Lee, Seungwoo; Kloba, Anthony; Hellmer, Ronald; Kumar, Nalin; Eaton, Mark; Rambo, Charlotte; Pillai, Suresh

    2011-06-01

    There is a strong desire for processes that improve the safety of water supplies and that minimize disinfection byproducts. Stellarray is developing mercury-free next-generation x-ray and UV-C radiation sources in flat-panel and pipe form factors for water and wastewater treatment applications. These new radiation sources are designed to sterilize sludge and effluent, and to enable new treatment approaches to emerging environmental concerns such as the accumulation of estrogenic compounds in water. Our UV-C source, based on cathodoluminescent technology, differs significantly from traditional disinfection approaches using mercury arc lamps or UV LEDs. Our sources accelerate electrons across a vacuum gap, converting their energy into UV-C when striking a phosphor, or x-rays when striking a metallic anode target. Stellarray's large area radiation sources for wastewater treatment allow matching of the radiation source area to the sterilization target area for maximum coverage and improved efficiency.

  4. UHE γ-rays from point sources based on GRAPES-I observations

    International Nuclear Information System (INIS)

    Gupta, S.K.; Sreekantan, B.V.; Srivatsan, R.; Tonwar, S.C.

    1993-01-01

    An experiment called GRAPES I (Gamma Ray Astronomy at PeV EnergieS) was set up in 1984 at Ooty in India, using 24 scintillation counters, to detect Extensive Air Showers (EAS) produced in the atmosphere by the primary cosmic radiation. The goal of the experiment has been to search for Ultra High Energy (UHE) γ-rays (E≥10 14 eV) from point sources in the sky. Here we discuss the results on X-ray binaries CYG X-3, HER X-1 and SCO X-1 obtained with GRAPES I experiment which covers the period 1984--87

  5. State Register of Sources of Ionizing Radiation and Occupational exposure

    CERN Document Server

    2002-01-01

    One of main tasks of Radiation Protection Centre is to collect, process, systematize, store and provide the data on sources of ionizing radiation and occupational exposures. The number of sources in 2002 is provided and compared with previous year. Distribution of workers according to the type of practice is compared with previous year. Distribution of sealed sources and x-ray machines according their use is presented.

  6. Dosimetric analysis of radiation sources to use in dermatological lesions

    International Nuclear Information System (INIS)

    Tada, Ariane

    2010-01-01

    Skin lesions undergoing therapy with radiation sources may have different patterns of malignancy. Malignant lesions or cancer most commonly found in radiotherapy services are carcinomas. Radiation therapy in skin lesions is performed with low penetration beams and orthovoltage X-rays, electron beams and radioactive sources ( 192 Ir, 198 Au, e 90 Sr) arranged on a surface mold or in metal applicator. This study aims to analyze the therapeutic radiation dose profile produced by radiation sources used in skin lesions radiotherapy procedures. Experimental measurements for the analysis of dosimetric radiation sources were compared with calculations obtained from a computer system based on the Monte Carlo Method. Computational results had a good agreement with the experimental measurements. Experimental measurements and computational results by the MCNP4C code have been used to validate the calculations obtained by MCNP code and to provide a reliable medical application for each clinical case. (author)

  7. Synchrotron radiation sources: general features and vacuum system

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1985-01-01

    In the last years the electron or positron storage rings, which were until 1970 only used for high energy physics experiments, begun to be built in several countries exclusively as electromagnetic radiation source (synchrotron radiation). The sources are generally made up by injector (linear accelerator or microtron), 'booster' (synchrotron), storage ring, insertions ('Wigglers' and ondulators) and light lines. The interest by these sources are due to the high intensity, large spectrum (from infrared to the X-rays), polarization and pulsed structure of the produced radiation. For the ultra-vacuum obtainement, necessary for the functioning storage rings (p=10 -9 Torr), several special procedures are used. In Brazil the Synchrotron Radiation National Laboratory of the CNPq worked out a conceptual project of synchrotron radiation source, whose execution should begin by the construction of the several components prototypes. (L.C.) [pt

  8. Recommendations for the safe use and regulation of radiation sources in industry, medicine, research and teaching

    International Nuclear Information System (INIS)

    1990-01-01

    The use of radiation sources of various types and activities is widespread in industry, medicine, research and teaching, and is increasing yearly. The safety record has been admirable, although incidents have occurred where loss of control of radiation sources has given rise to unplanned exposures to workers, medical patients and members of the public, sometimes with fatal results, while in other situations exposure may not have been as low as reasonably achievable. This publication is intended as a practical aid for all concerned with operational radiation protection connected with the use of radiation sources in industry, medicine, research and teaching, from the point of view of both the user of such sources and the regulatory bodies. Refs, figs

  9. Morphology, chemistry and distribution of neoformed spherulites in agricultural land affected by metallurgical point-source pollution

    NARCIS (Netherlands)

    Leguedois, S.; Oort, van F.; Jongmans, A.G.; Chevalier, P.

    2004-01-01

    Metal distribution patterns in superficial soil horizons of agricultural land affected by metallurgical point-source pollution were studied using optical and electron microscopy, synchrotron radiation and spectroscopy analyses. The site is located in northern France, at the center of a former entry

  10. Radiation sources EB and UV curing machines

    International Nuclear Information System (INIS)

    Takashi Sasaki

    1993-01-01

    This paper describes electron beam processors and related technologies for curing applications to facilitate those industrial personals who are trying to understand and evaluate the applicability and benefits of radiation curing to their products. 4 tabs., 10 figs

  11. THE ROLE OF RADIATION ACCIDENTS AND INDUSTRIAL APPLICATIONS OF IONIZING RADIATION SOURCES IN THE PROBLEM OF RADIATION DAMAGE

    OpenAIRE

    Кіхтенко, Ігор Миколайович

    2016-01-01

    Subject of research – the relevance of radiation damage at modern development of industry and medicine. In the world of radiation sources used in different fields of practice and their application in the future will increase, which greatly increases the likelihood of injury in a significant contingent of people.Research topic – the definition of the role of nuclear energy and the industrial use of ionizing radiation sources in the problem of radiation damage. The purpose of research – identif...

  12. Natural sources of ionizing radiation in Europe

    International Nuclear Information System (INIS)

    Green, B.M.R.; Hughes, J.S.; Lomas, P.R.

    1993-01-01

    This publication maps levels of radiation of natural origin throughout the European Community (except in the Lander of the former German Democratic Republic), in Scandinavia and in Austria. The booklet explains in simple terms the basic properties and origin of different types of radiation (cosmic rays, gamma rays and radon) and their contribution to the overall exposure of the population. A glossary, a list of administrative regions used in the maps and detailed references to the data for each country are included

  13. Challenges in Regulating Radiation Sources and Radioactive Waste in Nigeria

    International Nuclear Information System (INIS)

    Ngwakwe, C.

    2016-01-01

    Identifying challenges that hamper the efficiency and efficacy of Regulatory Infrastructure (People and Processes) as regards ensuring safety & security of radiation sources and radioactive waste is a major step towards planning for improvement. In a world constantly motivated by technological advancements, there has been considerable increase in the use of new technologies incorporating radioactive sources in both medical and industrial applications due to its perceived benefits, hence changing the dynamics of regulation. This paper brings to the fore, contemporary challenges experienced by regulators in the course of regulating radiation sources and radioactive waste in Nigeria. These challenges encountered in the business of regulating radiation sources and radioactive waste in Nigeria amongst others include; knowledge gap in the use of novel technologies for industrial applications (e.g. radiotracers in oil & gas and wastewater management), inadequate collaboration with operators to ensure transparency in their operations, inadequate cooperation from other government agencies using ionizing radiation sources, lack of synergy between relevant government agencies, difficulty in establishing standard radioactive waste management facility for orphan & disused sources, and inadequate control of NORMS encountered in industrial activities (e.g. well logging, mining). Nigerian Nuclear Regulatory Authority (NNRA), the body saddled with the responsibility of regulating the use of ionizing radiation sources in Nigeria is empowered by the Nuclear Safety and Radiation Protection Act to ensure the protection of life, property, and the environment from the harmful effects of ionizing radiation, hence are not immune to the aforementioned challenges. (author)

  14. Development of Yb-169 radiation source for new nondestructive inspection

    International Nuclear Information System (INIS)

    Yamabayashi, Hisamichi

    1994-01-01

    As the nondestructive inspection method for large structures, there has been radiography, and X-ray and γ-ray have been used as the radiation. The transmissivity of radiation through materials changes by the energy of the radiation and the density and thickness of the materials. At present about 880 γ-ray radiography apparatuses are used in Japanese private enterprises, and about 70% of them use 192 Ir γ-ray sources, and about 30% use 60 Co or 137 Cs sources. Recently the defect inspection for the worlded parts of thin wall small tubes and so on have become to be regarded as important, and the 169 Yb source that emits lower energy γ-ray is suitable to the purpose. There are many reports that 169 Yb radiography was applied successfully. As the 169 Yb radiation source, pellets and balls are on the market. 169 Yb is made by the neutron irradiation of 168 Yb in nuclear reactors. The characteristics of 169 Yb, the manufacture of 169 Yb radiation sources and the applicability of 169 Yb radiation sources to nondestructive inspection are reported. Also in Japan, many basic experiments on 169 Yb radiation sources have been carried out, and the irradiation apparatuses are small and light, and the control area can be set small. (K.I.)

  15. Modern state of the application of ionizing radiation for protection of environment. 1. Ionizing radiation sources. Purification of natural and drinking water (review)

    International Nuclear Information System (INIS)

    Pikaev, AK.

    2000-01-01

    Review of modern state of the application of ionizing radiations for protection of environment and natural and drinking water purification is presented. Building of installations with electron accelerators with summarized power of beam ∼0.6 MW signifies that application of ionizing radiation for ecological needs increase. It is pointed out that extensible application of electron accelerators is explained by their safety and efficiency as compared with gamma-sources. New information about ionizing radiation sources, radiation-chemical purification of polluted natural and drinking water, mechanisms of processes taking place during treatment by ionizing radiations are generalized [ru

  16. Chorus Emission Source Spatial Scales in the Terrestrial Radiation Belts

    Science.gov (United States)

    Agapitov, O. V.; Mozer, F.; Blum, L. W.; Wygant, J. R.; Bonnell, J. W.; Shastun, V.

    2016-12-01

    The key parameters for either non-linear wave particle interactions or for the quasi-linear approach are the temporal and spatial scales of the wave source region and coherence of the oscillations in a wave package. Both of these scales (the source scale and the coherence scale) are not well-established experimentally. We investigated both of these scales using coordinated multi-point measurements from the THEMIS and Van Allen Probes missions. To accomplish these objectives, we collected long intervals of six components VLF wave measurements (16384 s-1) aboard the Van Allen Probes in the outer radiation belt during close lapping events. The spatial scales of the chorus wave source region have been found to be around 400-600 km in transverse to the background magnetic field direction for L-shells from 4 to 6. The coherence spatial and temporal scales for chorus has been found to be less/about 100 km. The results obtained from the high resolution waveform analysis have been confirmed by the THEMIS continuous measurements (FBK and FFT)

  17. Introduction to radiation protection practical knowledge for handling radioactive sources

    CERN Document Server

    Grupen, Claus

    2010-01-01

    The book presents an accessible account of the sources of ionising radiation and the methods of radiation protection. The basics of nuclear physics which are directly related to radiation protection are briefly discussed. The book describes the units of radiation protection, the measurement techniques, biological effects of radiation, environmental radiation, and many applications of radiation. For each chapter there is a problem section with full solutions. A detailed glossary and many useful information in appendixes complete the book. The author has addressed the issue of internationality to make sure that the text and, in particular, the complicated regulations can be easily interpreted not only in Europe and the United States but also in other countries. The subject of radiation protection requires a certain amount of mathematics. For those who have forgotten the basic rules of calculus a short refresher course in the form of a mathematical appendix is added.

  18. Infrared point sources aligned with the SgrA(asterisk) non-thermal radio source

    Science.gov (United States)

    Stein, W. A.; Forrest, W. J.

    1986-01-01

    Assembled 0.7-5.0 micron observational data for two point sources approximately aligned with the compact nonthermal radio source SgrA(asterisk) in the Galactic center, thus far interpreted as being from the same object on the basis of their position and spectral continuity, are presently given alternative interpretations. While the object must be a hot star surrounded by a circumstellar dust cloud if it is a foreground star, a Galactic center position calls for an unorthodox extinction curve which suggests that the IR emission may be the Rayleigh-Jeans tail of a hot star or star cluster, or perhaps a thermal accretion disk.

  19. Multiwavelength counterparts of the point sources in the Chandra Source Catalog

    Science.gov (United States)

    Reynolds, Michael; Civano, Francesca Maria; Fabbiano, Giuseppina; D'Abrusco, Raffaele

    2018-01-01

    The most recent release of the Chandra Source Catalog (CSC) version 2.0 comprises more than $\\sim$350,000 point sources, down to fluxes of $\\sim$10$^{-16}$ erg/cm$^2$/s, covering $\\sim$500 deg$^2$ of the sky, making it one of the best available X-ray catalogs to date. There are many reasons to have multiwavelength counterparts for sources, one such reason is that X-ray information alone is not enough to identify the sources and divide them between galactic and extragalactic origin, therefore multiwavelength data associated to each X-ray source is crucial for classification and scientific analysis of the sample. To perform this multiwavelength association, we are going to employ the recently released versatile tool NWAY (Salvato et al. 2017), based on a Bayesian algorithm for cross-matching multiple catalogs. NWAY allows the combination of multiple catalogs at the same time, provides a probability for the matches, even in case of non-detection due to different depth of the matching catalogs, and it can be used by including priors on the nature of the sources (e.g. colors, magnitudes, etc). In this poster, we are presenting the preliminary analysis using the CSC sources above the galactic plane matched to the WISE All-Sky catalog, SDSS, Pan-STARRS and GALEX.

  20. Regulatory control of radiation sources in Germany

    International Nuclear Information System (INIS)

    Coy, K.

    1998-01-01

    The regulatory programme governing the safe use of radioisotopes in Germany is based on the federal legislation enacted as Atomic Energy Control Act (Atomgesetz) and Radiation Protection Ordinance (Strahlen-schutzverordnung) and its implementation by the competent authorities of the individual states. Despite this highly decentralized infrastructure of enforcement the basic principles of regulations described in this paper such as authorization criteria, conditions imposed as well as depth and intensity of inspection balanced according to the individual radiation hazard involved are harmonized to the greatest possible extent by regular coordination among the competent authorities as well as a series of technical regulations such as standards and guidelines. (author)

  1. Optical Imaging of Ionizing Radiation from Clinical Sources.

    Science.gov (United States)

    Shaffer, Travis M; Drain, Charles Michael; Grimm, Jan

    2016-11-01

    Nuclear medicine uses ionizing radiation for both in vivo diagnosis and therapy. Ionizing radiation comes from a variety of sources, including x-rays, beam therapy, brachytherapy, and various injected radionuclides. Although PET and SPECT remain clinical mainstays, optical readouts of ionizing radiation offer numerous benefits and complement these standard techniques. Furthermore, for ionizing radiation sources that cannot be imaged using these standard techniques, optical imaging offers a unique imaging alternative. This article reviews optical imaging of both radionuclide- and beam-based ionizing radiation from high-energy photons and charged particles through mechanisms including radioluminescence, Cerenkov luminescence, and scintillation. Therapeutically, these visible photons have been combined with photodynamic therapeutic agents preclinically for increasing therapeutic response at depths difficult to reach with external light sources. Last, new microscopy methods that allow single-cell optical imaging of radionuclides are reviewed. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  2. Stochastic electromagnetic radiation of complex sources

    NARCIS (Netherlands)

    Naus, H.W.L.

    2007-01-01

    The emission of electromagnetic radiation by localized complex electric charge and current distributions is studied. A statistical formalism in terms of general dynamical multipole fields is developed. The appearing coefficients are treated as stochastic variables. Hereby as much as possible a

  3. Transport of cobalt-60 industrial radiation sources

    Science.gov (United States)

    Kunstadt, Peter; Gibson, Wayne

    This paper will deal with safety aspects of the handling of Cobalt-60, the most widely used industrial radio-isotope. Cobalt-60 is a man-made radioisotope of Cobalt-59, a naturally occurring non radioactive element, that is made to order for radiation therapy and a wide range of industrial processing applications including sterilization of medical disposables, food irradiation, etc.

  4. Rules and regulations on ionizing radiations sources installations

    International Nuclear Information System (INIS)

    1980-01-01

    The finality of this legislative text is to establish the standards and procedures for site, design, building, operation and decommissioning of nuclear installations, radioactive installations and ionizing radiations sources. This text include the commercialization of radioactive substances and equipment fabrication

  5. Regulatory aspects of radiation sources safety in Albania

    International Nuclear Information System (INIS)

    Dollani, K.; Kushe, R.

    1998-01-01

    In this paper are presented the regulatory aspects of the radiation sources safety in Albania, based in the new Radiological Protection Act and Regulations. The radiation protection infrastructures and procedures are described as well as their functioning for the implementation of relevant activities such as licensing and regular inspection, personal dose monitoring, emergency preparedness which are developed in the frame of the IAEA Technical Co-operation Programme. The issue of the security of radiation sources is dealt in close relation with the preparation and use of the inventory of all radiation sources in the country. A special attention is paid to the identification and location of lost sources for their finding and secure storage. (author)

  6. Source book of educational materials for radiation therapy. Final report

    International Nuclear Information System (INIS)

    Pijar, M.L.

    1979-08-01

    The Source Book is a listing of educational materials in radiation therapy technology. The first 17 sections correspond to the subjects identified in the ASRT Curriculum Guide for schools of radiation therapy. Each section is divided into publications and in some sections audiovisuals and training aids. Entries are listed without endorsement

  7. Terahertz radiation source using a high-power industrial electron ...

    Indian Academy of Sciences (India)

    2017-03-27

    Mar 27, 2017 ... 2Accelerator and Beam Physics Laboratory, Raja Ramanna Centre for Advanced Technology, ... electron beam-based sources, e.g., backward wave ..... THz wave [3,22]. The phase-sensitive imaging appli- cations require highly spatial or transverse coherent radiation [5,28,42]. THz undulator radiation in ...

  8. Ionizing radiation sources in Tunisia in 1993; Les sources de rayonnements ionisants en Tunisie en 1993

    Energy Technology Data Exchange (ETDEWEB)

    Chahed, N.

    1996-10-01

    This document presents the different sources of ionizing radiations in Tunisia. Those radiations are characterized by alpha and gamma particles which are emitted by electric generators, research reactors and power reactors in nuclear plants. Four fields usually use ionizing radiations: medical, industrial, agricultural and research fields. Then different evolutions are studied: evolution in time, classification in fields, distribution in the country. Finally, the different problems caused by these sources are presented and solutions are put forward. (TEC). 4 figs.

  9. Challenges in Regulating Radiation Sources and Associated Waste Management

    International Nuclear Information System (INIS)

    Shehzad, A.

    2016-01-01

    Radiation sources are widely used in the fields of medical, industry, agriculture, research, etc. Owing to the inherent risk of exposure to ionizing radiations while using the radiation sources and management of associated waste, safety measures are of utmost importance including robust regulatory control. Pakistan Nuclear Regulatory Authority (PNRA) is responsible for supervising all matters pertaining to nuclear safety and radiation protection in the country. Since its inception, PNRA has made rigorous efforts to regulate the radiation facilities for which regulatory framework was further strengthened by taking into account international norms/practices and implemented afterwards. However, due to vibrant use of these facilities, there are numerous challenges being faced while implementing the regulatory framework. These challenges pertains to shielding design of some facilities, control over service provider for QC/repair maintenance of radiation equipment, assessment of patient doses, and establishment of national diagnostic reference levels for radiological procedures. Further, the regulatory framework also delineate requirements to minimize the generation of associated radioactive waste as low as practicable. The requirements also necessitates that certain sealed radioactive sources (SRS) are returned to the supplier upon completion of their useful life, while other radioactive sources are required to be transported for storage at designated radioactive waste storage facilities in the country, which requires commitment from the licensee. This paper will briefly describe the challenges in regulating the radiation sources and issues related to the waste management associated with these facilities. (author)

  10. Experience with qualification examinations of workers handling ionizing radiation sources

    International Nuclear Information System (INIS)

    Skokanova, K.

    1976-01-01

    The organization is described of examinations which have to be passed by supervising staff and workers using radioactive ionizing radiation sources. The requirements are listed of the examination in which these workers have to prove their professional knowledge and skills. The said examinations significantly contribute to the establishment of a system of safeguards at workplaces using ionizing radiation sources and may help economize operations at these workplaces

  11. Radiation Source Mapping with Bayesian Inverse Methods

    Science.gov (United States)

    Hykes, Joshua Michael

    We present a method to map the spectral and spatial distributions of radioactive sources using a small number of detectors. Locating and identifying radioactive materials is important for border monitoring, accounting for special nuclear material in processing facilities, and in clean-up operations. Most methods to analyze these problems make restrictive assumptions about the distribution of the source. In contrast, the source-mapping method presented here allows an arbitrary three-dimensional distribution in space and a flexible group and gamma peak distribution in energy. To apply the method, the system's geometry and materials must be known. A probabilistic Bayesian approach is used to solve the resulting inverse problem (IP) since the system of equations is ill-posed. The probabilistic approach also provides estimates of the confidence in the final source map prediction. A set of adjoint flux, discrete ordinates solutions, obtained in this work by the Denovo code, are required to efficiently compute detector responses from a candidate source distribution. These adjoint fluxes are then used to form the linear model to map the state space to the response space. The test for the method is simultaneously locating a set of 137Cs and 60Co gamma sources in an empty room. This test problem is solved using synthetic measurements generated by a Monte Carlo (MCNP) model and using experimental measurements that we collected for this purpose. With the synthetic data, the predicted source distributions identified the locations of the sources to within tens of centimeters, in a room with an approximately four-by-four meter floor plan. Most of the predicted source intensities were within a factor of ten of their true value. The chi-square value of the predicted source was within a factor of five from the expected value based on the number of measurements employed. With a favorable uniform initial guess, the predicted source map was nearly identical to the true distribution

  12. Nutrient Losses from Non-Point Sources or from Unidentified Point Sources? Application Examples of the Smartphone Based Nitrate App.

    Science.gov (United States)

    Rozemeijer, J.; Ekkelenkamp, R.; van der Zaan, B.

    2017-12-01

    In 2016 Deltares launched the free to use Nitrate App which accurately reads and interprets nitrate test strips. The app directly displays the measured concentration and gives the option to share the result. Shared results are visualised in map functionality within the app and online. Since its introduction we've been seeing an increasing number of nitrate app applications. In this presentation we show some unanticipated types of application. The Nitrate App was originally intended to enable farmers to measure nitrate concentrations on their own farms. This may encourage farmers to talk to specialists about the right nutrient best management practices (BMP's) for their farm. Several groups of farmers have recently started to apply the Nitrate App and to discuss their results with each other and with the authorities. Nitrate concentration routings in catchments have proven to be another useful application. Within a day a person can generate a catchment scale nitrate concentration map identifying nitrate loss hotspots. In several routings in agricultural catchments clear point sources were found, for example at small scale manure processing plants. These routings proved that the Nitrate App can help water managers to target conservation practices more accurately to areas with the highest nitrate concentrations and loads. Other current applications are the screening of domestic water wells in California, the collection of extra measurements (also pH and NH4) in the National Monitoring Network for the Evaluation of the Manure Policy in the Netherlands, and several educational initiatives in cooperation with schools and universities.

  13. Derivation of the blackbody radiation spectrum from the equivalence principle in classical physics with classical electromagnetic zero-point radiation

    International Nuclear Information System (INIS)

    Boyer, T.H.

    1984-01-01

    A derivation of Planck's spectrum including zero-point radiation is given within classical physics from recent results involving the thermal effects of acceleration through classical electromagnetic zero-point radiation. A harmonic electric-dipole oscillator undergoing a uniform acceleration a through classical electromagnetic zero-point radiation responds as would the same oscillator in an inertial frame when not in zero-point radiation but in a different spectrum of random classical radiation. Since the equivalence principle tells us that the oscillator supported in a gravitational field g = -a will respond in the same way, we see that in a gravitational field we can construct a perpetual-motion machine based on this different spectrum unless the different spectrum corresponds to that of thermal equilibrium at a finite temperature. Therefore, assuming the absence of perpetual-motion machines of the first kind in a gravitational field, we conclude that the response of an oscillator accelerating through classical zero-point radiation must be that of a thermal system. This then determines the blackbody radiation spectrum in an inertial frame which turns out to be exactly Planck's spectrum including zero-point radiation

  14. Feed network and electromagnetic radiation source

    Science.gov (United States)

    Ardavan, Arzhang; Singleton, John; Linehan, Kevin E.; Ardavan, Houshang; Schmidt-Zwiefel, Andrea Caroline

    2017-01-17

    An antenna may include a volume polarization current radiator and a feed network. The volume polarization current radiator, includes a dielectric solid (such as a dielectric strip), and a plurality of closely-spaced excitation elements (24), each excitation element (24) being configured to induce a volume polarization current distribution in the dielectric solid proximate to the excitation element when a voltage is applied to the excitation element. The feed network is coupled to the volume polarization current radiator. The feed network also includes a plurality of passive power divider elements (32) and a plurality of passive delay elements (d1-d6) coupling the first port (30) and the plurality of second ports (108, 109, 164), the plurality of power divider elements (32) and the plurality of phase delay elements (d1-d6) being configured such that a radio-frequency signal that is applied to the first port (30) experiences a progressive change of phase as it is coupled to the plurality of second ports (108, 109, 164) so as to cause the volume polarization current distribution to propagate along the dielectric solid.

  15. Evaluation of methods to leak test sealed radiation sources

    International Nuclear Information System (INIS)

    Arbeau, N.D.; Scott, C.K.

    1987-04-01

    The methods for the leak testing of sealed radiation sources were reviewed. One hundred and thirty-one equipment vendors were surveyed to identify commercially available leak test instruments. The equipment is summarized in tabular form by radiation type and detector type for easy reference. The radiation characteristics of the licensed sources were reviewed and summarized in a format that can be used to select the most suitable detection method. A test kit is proposed for use by inspectors when verifying a licensee's test procedures. The general elements of leak test procedures are discussed

  16. The Advanced Light Source (ALS) Radiation Safety System

    International Nuclear Information System (INIS)

    Ritchie, A.L.; Oldfather, D.E.; Lindner, A.F.

    1993-08-01

    The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 Gev synchrotron light source facility consisting of a 120 kev electron gun, 50 Mev linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage ring, and many photon beamline transport systems for research. Figure 1. ALS floor plan. Pairs of neutron and gamma radiation monitors are shown as dots numbered from 1 to 12. The Radiation Safety System for the ALS has been designed and built with a primary goal of providing protection against inadvertent personnel exposure to gamma and neutron radiation and, secondarily, to enhance the electrical safety of select magnet power supplies

  17. Background radiation and man-made and sources of radiation

    International Nuclear Information System (INIS)

    Babalola, I.A.

    1997-01-01

    This paper describes the development of the use of the atom and its present applications in food and agriculture, industry medicine and health care, energy-environment and research. These applications have inevitably led to concerns about nuclear safety and radioactive waste management and the need for the adoption of procedures for control, safe use and disposal of radioactive sources

  18. Technological yields of sources for radiation processing

    International Nuclear Information System (INIS)

    Zagorski, Z.P.

    1993-01-01

    The present report is prepared for planners of radiation processing of any material. Calculations are focused on accelerators of electrons, divided into two groups: versatile linacs of energy up to 13 MeV, and accelerators of lower energy, below 2 MeV, of better energy yield but of limited applications. The calculations are connected with the confrontation of the author's technological expectations during the preparation of the linac project in the late '60s, with the results of 25 years of exploitation of the machine. One has to realize that from the 200 kW input power from the mains, only 5 kW of bent and scanned beam is recovered on the conveyor. That power is only partially used for radiation induced phenomena, because of the demanded homogeneity of the dose, of the mode of packing of the object and its shape, of edges of the scanned area and in the spaces between boxes, and of loses during the idle time due to the tuning of the machine and dosimetric operations. The use of lower energy accelerators may be more economical than that of linacs in case of objects of specific type. At the first stage already, that is of the conversion of electrical power into that of low energy electron beam, the yield is 2-3 times better than in the case of linacs. Attention has been paid to the technological aspects of electron beam conversion into the more penetrating Bremsstrahlung similar to gamma radiation. The advantages of technologies, which make possible a control of the shape of the processed object are stressed. Special attention is focused to the relation between the yield of processing and the ratio between the maximum to the minimum dose in the object under the irradiation. (author). 14 refs, 14 figs

  19. Impact of point source pollution on groundwater quality

    International Nuclear Information System (INIS)

    Gill, M.A.; Solehria, B.A.; Rai, N.I.

    2005-01-01

    The management of point source pollution (municipal and industrial waste water) is an important item on Brown Agenda confronting urban planners and policy makers. The industrial concerns and households produce enormous amount of waste water, which has to be disposed of through the municipal sewage system. Generally, municipal wastewater management is done on non-scientific lines, resulting in considerable social and economic loss and gradual degradation of the natural resources. The present study highlights that how the poor management practices, lack of infrastructure, and poor disposal system-comprising of mostly open, un-walled or partially lined drains, affect the groundwater quality and render it unfit for human consumption. Satiana Road sludge carrier at Faisalabad city, receiving effluents of about 67 textile units, 4 oil mills, 2 ice factories, 3 laundris and domestic waste water of Peoples Colony No.1, Maqbool Road and Ghulam Rasool Nagar was selected to derive quantitative and qualitative estimates of TDS, Na, Cl and heavy metals namely Fe, Cu and Pb of the waste water and their leaching around the sludge carrier. The measurement of leaching of TDS, Na/sup +/, and Cl/sup -1/ per 1000 m basis in lined section was 818, 550 and 228 tons, respectively. Where as in the unlined section, annual increase of TDS, Na/sup /+, and Cl/sup -/ was 2404,1615 and 669 tons per 1000 m respectively. In case of leaching of metals through the sludge carrier, Cu was at the top with 8.4 tons per annum per 1000 m followed by Fe and Pb with 6.66 and 1.2 tons per annum per 1000 m respectively. The concentration of all the salts/metals studied were higher in groundwater near the sludge carrier which decreased with increase in distance. The groundwater contamination in unlined portions is greater than lined portions, which might be due to higher seepage losses in unlined portions of the sludge carrier (4.9 % per 1000 m) as compared to relatively low seepage losses in lined portion of

  20. Radiation safety aspects of fluorescent lamp starters incorporating radiation source

    International Nuclear Information System (INIS)

    Sadagopan, Geetha; Shukla, V.K.

    2000-01-01

    A fluorescent lamp starter is a switch applies the voltage to the fluorescent tube after sufficient preheating to allow the tube to conduct an electric current. Radioactive substances used in the starters are 85 Kr, 147 Pm, 3 H and 232 Th. In India, fluorescent lamp starters are classified as consumer products and users are outside regulatory control. However, regulatory control is exercised over the manufacturers at the production stage. Tritium activity measured in the lamp starters ranged from 400-4500 Bq with a mean activity of 1.78 kBq. Thorium activity measured varied from 0.44-3.3 mg. The results of radiation safety assessment of the workplace and radioactivity estimation in the starters are discussed in this paper. (author)

  1. Open Source Radiation Hardened by Design Technology

    Science.gov (United States)

    Shuler, Robert

    2016-01-01

    The proposed technology allows use of the latest microcircuit technology with lowest power and fastest speed, with minimal delay and engineering costs, through new Radiation Hardened by Design (RHBD) techniques that do not require extensive process characterization, technique evaluation and re-design at each Moore's Law generation. The separation of critical node groups is explicitly parameterized so it can be increased as microcircuit technologies shrink. The technology will be open access to radiation tolerant circuit vendors. INNOVATION: This technology would enhance computation intensive applications such as autonomy, robotics, advanced sensor and tracking processes, as well as low power applications such as wireless sensor networks. OUTCOME / RESULTS: 1) Simulation analysis indicates feasibility. 2)Compact voting latch 65 nanometer test chip designed and submitted for fabrication -7/2016. INFUSION FOR SPACE / EARTH: This technology may be used in any digital integrated circuit in which a high level of resistance to Single Event Upsets is desired, and has the greatest benefit outside low earth orbit where cosmic rays are numerous.

  2. Ionizing radiation sources used in medical applications in Brazil

    International Nuclear Information System (INIS)

    Araujo, A.M.C.; Carlos, M.T.; Cruz, L.R.F.; Domingues, C.; Farias, J.T.; Ferreira, R.; Figueiredo, L.; Peixoto, J.E.; Oliveira, S.M.V.; Drexler, G.

    1991-02-01

    Preliminary data about ionizing radiation sources used in medical applications and obtained through a national programme by IRD/CNEN together with Brazilian health authorities are presented. The data presentation follows, as close as possible, recommendations given by the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR). This programme has two main aims: First: to contribute for research in the field of ionizing radiation effects and risks including information about equipment quality control and procedures adopted by professionals working in Radiation Medicine. Second: to investigate the radiation protection status in Brazil, in order to give assistance to Brazilian health authorities for planning regional radiation programmes and training programmes for medical staffs. (F.E.). 13 refs, 19 figs, 34 tabs

  3. Solar radiation data sources, applications, and network design

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    A prerequisite to considering solar energy projects is to determine the requirements for information about solar radiation to apply to possible projects. This report offers techniques to help the reader specify requirements in terms of solar radiation data and information currently available, describes the past and present programs to record and present information to be used for most requirements, presents courses of action to help the user meet his needs for information, lists sources of solar radiation data and presents the problems, costs, benefits and responsibilities of programs to acquire additional solar radiation data. Extensive background information is provided about solar radiation data and its use. Specialized information about recording, collecting, processing, storing and disseminating solar radiation data is given. Several Appendices are included which provide reference material for special situations.

  4. Radiometric analyzer with plural radiation sources and detectors

    International Nuclear Information System (INIS)

    Arima, S.; Oda, M.; Miyashita, K.; Takada, M.

    1977-01-01

    A radiometric analyzer for measuring characteristics of a material by radiation comprises a plurality of systems in which each consists of a radiation source and a radiation detector which are the same in number as the number of elements of the molecule of the material and a linear calibration circuit having inverse response characteristics (calibration curve) of the respective systems of detectors, whereby the measurement is carried out by four fundamental rules by operation of the mutual outputs of said detector system obtained through said linear calibration circuit. One typical embodiment is a radiometric analyzer for hydrocarbons which measures the density of heavy oil, the sulfur content and the calorific value by three detector systems which include a γ-ray source (E/sub γ/ greater than 50 keV), a soft x-ray source (Ex approximately 20 keV), and a neutron ray source. 2 claims, 6 figures

  5. Regulatory control for safe usage of radiation sources in India

    International Nuclear Information System (INIS)

    Ghosh, P.K.; Sonawane, A.U.

    1998-01-01

    The widespread applications of radioactive materials and radiation generating equipment in the field of industry, medicine agriculture and research in India necessitated the establishment of an efficient regulatory framework and consequently the Atomic Energy Regulatory Board (AERB) was constituted to exercise regulatory control over the safe usage of the radioactive materials and the radiation generating equipment. The Atomic Energy Act, 1962 and the Radiation Protection Rules, 1971 promulgated under the Act forms the basis of radiation safety in India and Chairman, AERB is the Competent Authority to enforce the regulatory provisions of the Radiation Protection Rules, 1971, for safe use of radiation source in the country. AERB has published a number of documents such as Radiation Surveillance Procedures, Standards, Codes, Guides and Manuals for safe use and handling of radioactive materials and radiation generating equipment. Apart from nuclear fuel cycle documents, these publications pertain to industrial radiography, medical application of radiation, transport of radioactive material, industrial gamma irradiators, X-ray units etc. AERB safety related publications are based on international standards e.g. BSS, IAEA, ICRP, ISO etc. This paper outlines the methodology of regulatory control exercised by AERB for safe use of the radioactive materials and the radiation generating equipment in the country. (author)

  6. Radiation protection and regulatory aspects in the use of radiation sources

    International Nuclear Information System (INIS)

    Sen, Amit; Dash Sharma, P.K.; Sonawane, A.U.

    2012-01-01

    The uses of ionising radiation sources (i.e. radioisotopes and radiation generating equipment such as accelerators and X-ray machines) for multifarious applications in industry, medicine, agriculture, research and teaching have been significantly increasing all over the world. In India, the application of radiation sources in various fields has registered phenomenal growth during the last decade. The use of radiation sources mainly include radiation processing for food preservation and sterilization of healthcare products, radiotherapy for treatment of cancer, nuclear medicine for diagnosis and therapy, gamma chambers for several R and D studies, blood irradiators, industrial radiography for non destructive examinations of steel structures, industrial ionising radiation gauging devices for monitoring/measurement of on-line quality control parameters (e.g. thickness, level, density, moisture, elemental analysis), consumer products such as gaseous tritium light sources (GTLS), gaseous tritium light devices (GTLD), ionisation chamber smoke detectors (ICSD), fluorescent light starters, antistatic devices and incandescent gas mantles containing thorium etc. All these beneficial applications involve use of both sealed and unsealed radioactive sources and amount of radioactivity varies from few kBq (μCi) to hundreds of TBq (thousands of curies). Radiation sources emit ionising radiations and if not handled properly and safely, may give rise to potential exposures leading to an unacceptable hazard. Therefore, it is necessary to ensure a high standard of safety and reliability in handling of radiation equipment and sources through their careful design by ensuring adequate built-in-safety as per applicable national/international standard, safe operation and periodic maintenance procedures, safe transport from one place to another, secured storage when not in use, physical security to radiation sources, effective emergency response plans and preparedness, including safe

  7. Data library of gamma-ray buildup factors for point isotropic source

    International Nuclear Information System (INIS)

    Sakamoto, Yukio; Tanaka, Shun-ichi; Harima, Yoshiko.

    1988-01-01

    Gamma-ray buildup factors for a point isotropic source have been calculated as a function of atomic number of heavy elements and source energies over an energy range from 0.015 MeV to 15 MeV, for penetration depths up to 40 mfp, bu the PALLAS-PL,SP-Br code. These data include the contribution of bremsstrahlung, annihilation radiation and fluorescence X-ray. The calculated absorbed-dose, exposure and dose-equivalent buildup factors are tabulated for molybdenum, tin, tungsten, lead and uranium, which are practical interest shield materials, lanthanum and gadolinium which are important materials for obtaining buildup factors by interpolation with the atomic number. In the case of high atomic number materials, inclusion of brems-strahlung source has great influence on the buildup factors for high source energies and that of fluorescence X-ray gives spectracular effects on those for low energies close to the K edge of attenuation cross section. Furthermore, the geometrical-progression (G-P) parameters have been determined for these buildup factors in order to obtain the values of buildup factors at arbitrary distances and energies. (author)

  8. LAT 2-year Point Source Catalog Aperture Photometry Lightcurves

    Data.gov (United States)

    National Aeronautics and Space Administration — Due to a glitch in the analysis pipeline there are apparent increases in flux around MJD 56810 for many sources. These increases are not real and should be...

  9. LAT 2-year Point Source Catalog Aperture Photometry Lightcurves Flares

    Data.gov (United States)

    National Aeronautics and Space Administration — Due to a glitch in the analysis pipeline there are apparent increases in flux around MJD 56810 for many sources. These increases are not real and should be...

  10. Control of radioisotopes and radiation sources in Indonesia

    International Nuclear Information System (INIS)

    Ridwan, M.

    2001-01-01

    Radioisotopes and radiation sources are extensively used in Indonesia in medicine, industry, mining, agriculture and research. These materials are controlled by the regulatory authority, according to established legal procedures. The Nuclear Energy Control Board of Indonesia (BAPETEN), which was established in 1998 through the Nuclear Energy Act No. 10/1997, is entrusted with the control of any application of nuclear energy, including the application of radioisotopes and radiation sources, through regulation, licensing and inspection. The control is aimed to assure welfare, security and peace, the safety and health of workers and the public, and environmental protection. The number of licences issued to date is around 2400, consisting of 1600 licences for radioisotopes and radiation sources used in hospitals, 347 in radiography, 256 in industry, 53 in mining, and the rest in many other areas such as research and agriculture. A licence can cover one or more radioisotopes or radiation sources, depending on the location of the user institution. These radioisotopes and radiation sources are Co-60, Cs-137, Ir-192, Ra-226, Am-241, Sr-90, Kr-85, Pm-147, linear accelerator and X-ray, and short half-life radioisotopes such as I-125, I-131 and Tc-99m. There are 10 LINACs, 27 X-ray medicines, 61 radioisotope devices for Co-60 and Cs-137, and 10 mHDR Ir-192 for therapeutic purposes currently used in Indonesia and some Ra-226 in storage. Any activity related to the application of nuclear energy is required to be conducted in a manner which observes safety and security. According to the legal requirements, each user has to employ at least one radiation safety officer. To improve the control of the application of radiation sources and radioactive material in the country, BAPETEN introduced some new approaches to the users, including regular dialogues with radiation safety officers and the management of the users, requalification for radiation protection officers twice in five

  11. Possible sources of radiation in indoor environment

    International Nuclear Information System (INIS)

    Djukanovic, M.

    1997-01-01

    More locations and building material will be needed to solve the housing needs, actually the future quantities will equal the total of all the previous building. And presently one quarter of the world population is already homeless. The development of human civilization in the new technological era goes on extremely quickly. In the search for new spaces, in the last decade of the 20th century, in town renovation planning the application of subterranean civil engineering is very popular. Below ground level, the new towns are built with many stories, with exclusively artificial light and artificial climate. There is not the slightest possibility of natural ventilation. These spaces have not been investigated as regards the contents of radon. Man is not adapted to spend most of the time in under artificial conditions. It is still to be discovered how it will affect humans and what is the degree of exposure to ionizing radiation in such conditions. It might be better to abandon underground construction before the adverse effects are proved. Previous mistakes in building must be overcome and new technologies applied as well as sustainable development in the future. (author)

  12. Evaluation of integrity of radiation sources of nuclear gauges

    International Nuclear Information System (INIS)

    Torohate, Wiclif Francisco

    2016-01-01

    Nuclear equipment meters are mainly used in the industry in quality control and process control. The principle of operation consists in a shielded radioactive source together with a radiation detector such that the radiation interacts with the material to be analyzed before reaching the detector, providing real time data. Can be as their fixed and mobile mobility, the unique properties of ionizing radiation are used in three basic modes, transmission, backscatter or dispersion or induced (reactive). With the advancement and technological modernization in the world, the demand for nuclear gauges becomes increasingly larger. Currently in Brazil there are about 465 process control plants and 21 portable systems and Mozambique about 45 facilities using nuclear gauges. This font registration is done through a process called source inventory that allows also to know the category of the source, the danger or risk to human health that the source offers. The handling of this equipment requires personnel, certified, skilled and well trained in radiation protection area in accordance with the requirements of the various CNEN Rules. Due to the presence of radioactive source and because these devices are used by workers risk because there external radiation. In this context, we made the smear test in two fixed meters from the IRD industry laboratory, which determines the integrity of the source package, mandatory item in periodic integrity testing of the radiation source of this type of device. A set of procedures is made for its implementation as an evaluation of the radiological risk by radiological survey. It was intended to contribute to the learning handling and safe use of these meters. (author)

  13. Analysis of point source size on measurement accuracy of lateral point-spread function of confocal Raman microscopy

    Science.gov (United States)

    Fu, Shihang; Zhang, Li; Hu, Yao; Ding, Xiang

    2018-01-01

    Confocal Raman Microscopy (CRM) has matured to become one of the most powerful instruments in analytical science because of its molecular sensitivity and high spatial resolution. Compared with conventional Raman Microscopy, CRM can perform three dimensions mapping of tiny samples and has the advantage of high spatial resolution thanking to the unique pinhole. With the wide application of the instrument, there is a growing requirement for the evaluation of the imaging performance of the system. Point-spread function (PSF) is an important approach to the evaluation of imaging capability of an optical instrument. Among a variety of measurement methods of PSF, the point source method has been widely used because it is easy to operate and the measurement results are approximate to the true PSF. In the point source method, the point source size has a significant impact on the final measurement accuracy. In this paper, the influence of the point source sizes on the measurement accuracy of PSF is analyzed and verified experimentally. A theoretical model of the lateral PSF for CRM is established and the effect of point source size on full-width at half maximum of lateral PSF is simulated. For long-term preservation and measurement convenience, PSF measurement phantom using polydimethylsiloxane resin, doped with different sizes of polystyrene microspheres is designed. The PSF of CRM with different sizes of microspheres are measured and the results are compared with the simulation results. The results provide a guide for measuring the PSF of the CRM.

  14. Synchrotron radiation phase-contrast X-ray CT imaging of acupuncture points

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dongming; Yan, Xiaohui; Zhang, Xinyi [Fudan University, Synchrotron Radiation Research Center, State Key Laboratory of Surface Physics and Department of Physics, Shanghai (China); Liu, Chenglin [Physics Department of Yancheng Teachers' College, Yancheng (China); Dang, Ruishan [The Second Military Medical University, Shanghai (China); Xiao, Tiqiao [Chinese Academy of Sciences, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Shanghai (China); Zhu, Peiping [Chinese Academy of Sciences, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Beijing (China)

    2011-08-15

    Three-dimensional (3D) topographic structures of acupuncture points were investigated by using synchrotron radiation in-line X-ray phase contrast computerized tomography. Two acupuncture points, named Zhongji (RN3) and Zusanli (ST36), were studied. We found an accumulation of microvessels at each acupuncture point region. Images of the tissues surrounding the acupuncture points do not show such kinds of structure. This is the first time that 3D images have revealed the specific structures of acupuncture points. (orig.)

  15. Synchrotron radiation phase-contrast X-ray CT imaging of acupuncture points

    International Nuclear Information System (INIS)

    Zhang, Dongming; Yan, Xiaohui; Zhang, Xinyi; Liu, Chenglin; Dang, Ruishan; Xiao, Tiqiao; Zhu, Peiping

    2011-01-01

    Three-dimensional (3D) topographic structures of acupuncture points were investigated by using synchrotron radiation in-line X-ray phase contrast computerized tomography. Two acupuncture points, named Zhongji (RN3) and Zusanli (ST36), were studied. We found an accumulation of microvessels at each acupuncture point region. Images of the tissues surrounding the acupuncture points do not show such kinds of structure. This is the first time that 3D images have revealed the specific structures of acupuncture points. (orig.)

  16. Strengthening the security of radiation sources in Ghana

    International Nuclear Information System (INIS)

    Emi-Reynolds, G.; Banini, G.K.; Flecther, J.J.; Ennison, I.; Schandorf, C.

    1998-01-01

    Legislative instrument LI 1559 of 1993 established the Radiation Protection Board (RPB) as the National Competent Authority (NCA) on radiation matters in Ghana. The Board advises Government through the Ghana Atomic Energy Commission on matters relating to radiation safety, security of sources, sales, import and export, contamination in food and environment, among others. It has wide ranging regulatory power and works in association with country authorities. The regulations in place for controlling the movement and use of radioactive materials in Ghana are discussed. Accountability for radioactive materials especially for those which were brought in before the establishment of the RPB have been the focus of our discussion. The need to for intensify educational programs for the public on matters relating to effect of radiation on man and environment is recommended. Strengthening of regulatory control of sources and intensifying efforts against smuggling, unauthorised use and systems for notification on radioactive transport accidents are noted. (author)

  17. Dosimetry services for internal and external radiation sources

    International Nuclear Information System (INIS)

    1988-01-01

    The Canadian Atomic Energy Control Board (AECB) sets radiation dose limits for the operation of nuclear facilities and the possession of prescribed substances within Canada. To administer these regulations the AECB must be satisfied that the dosimetry services used by a licensee meet adequate standards. Licensees are required to use the Occupational Dosimetry Service operated by the Bureau of Radiation and Medical Devices, Department of National Health and Welfare (BRMD) to determine doses from external sources of radiation, except where a detailed rationale is given for using another service. No national dosimetry service exists for internal sources of radiation. Licensees who operate or use a dosimetry service other than the BRMD must provide the AECB with evidence of the competence of the staff and adequacy of the equipment, techniques and procedures; provide the AECB with evidence that a quality assurance program has been implemented; and send individual dose or exposure data to the National Dose Registry. (L.L.)

  18. A point kernel algorithm for microbeam radiation therapy

    Science.gov (United States)

    Debus, Charlotte; Oelfke, Uwe; Bartzsch, Stefan

    2017-11-01

    Microbeam radiation therapy (MRT) is a treatment approach in radiation therapy where the treatment field is spatially fractionated into arrays of a few tens of micrometre wide planar beams of unusually high peak doses separated by low dose regions of several hundred micrometre width. In preclinical studies, this treatment approach has proven to spare normal tissue more effectively than conventional radiation therapy, while being equally efficient in tumour control. So far dose calculations in MRT, a prerequisite for future clinical applications are based on Monte Carlo simulations. However, they are computationally expensive, since scoring volumes have to be small. In this article a kernel based dose calculation algorithm is presented that splits the calculation into photon and electron mediated energy transport, and performs the calculation of peak and valley doses in typical MRT treatment fields within a few minutes. Kernels are analytically calculated depending on the energy spectrum and material composition. In various homogeneous materials peak, valley doses and microbeam profiles are calculated and compared to Monte Carlo simulations. For a microbeam exposure of an anthropomorphic head phantom calculated dose values are compared to measurements and Monte Carlo calculations. Except for regions close to material interfaces calculated peak dose values match Monte Carlo results within 4% and valley dose values within 8% deviation. No significant differences are observed between profiles calculated by the kernel algorithm and Monte Carlo simulations. Measurements in the head phantom agree within 4% in the peak and within 10% in the valley region. The presented algorithm is attached to the treatment planning platform VIRTUOS. It was and is used for dose calculations in preclinical and pet-clinical trials at the biomedical beamline ID17 of the European synchrotron radiation facility in Grenoble, France.

  19. Radiation safety of sealed sources and equipment containing them

    International Nuclear Information System (INIS)

    1993-01-01

    The guide gives information and requirements concerning the technical construction, installation, use and licensing of devices containing sealed radioactive sources in order to ensure the operational safety. The requirements are in accordance with the international standards ISO 1677, ISO 2919, ISO 7205 and Nordic Recommendations on radiation protection for radionuclide gauges in permanent installation. The guide explains also the practical measures that must be taken into account when a radiation device is repaired, maintained or removed from the use. (8 refs.)

  20. Radiological Protection Experience with natural sources of radiation

    International Nuclear Information System (INIS)

    Quindos, L. S.; Fernandez, P. L.; Vinuela, J.; Arteche, J.; Sainz, G.; Gomez, J.; Matarranz

    2003-01-01

    During the last twenty five years the research Radon Group of the Medical Physics Unit of the University of Cantabria has been involved in projects concerning the measurement of natural radiation, in special that coming from radon gas. At this moment we have available for this field a lot of information in different formats, as paper, video and CD, interesting not only for public in general but also for professionals interested in the evaluation of doses coming from natural sources of radiation. (Author)

  1. Exposure buildup factors for a cobalt-60 point isotropic source for single and two layer slabs

    International Nuclear Information System (INIS)

    Chakarova, R.

    1992-01-01

    Exposure buildup factors for point isotropic cobalt-60 sources are calculated by the Monte Carlo method with statistical errors ranging from 1.5 to 7% for 1-5 mean free paths (mfp) thick water and iron single slabs and for 1 and 2 mfp iron layers followed by water layers 1-5 mfp thick. The computations take into account Compton scattering. The Monte Carlo data for single slab geometries are approximated by Geometric Progression formula. Kalos's formula using the calculated single slab buildup factors may be applied to reproduce the data for two-layered slabs. The presented results and discussion may help when choosing the manner in which the radiation field gamma irradiation units will be described. (author)

  2. Determining and modeling the dispersion of non point source ...

    African Journals Online (AJOL)

    In this study, pollutants in runoff are characterized and their dispersion after they enter the lake is measured and modeled at different points in the study areas. The objective is to develop a one dimensional mathematical model which can be used to predict the nutrient (ammonia, nitrite, nitrate, and phosphate) dispersion ...

  3. POINT CLOUD VISUALIZATION IN AN OPEN SOURCE 3D GLOBE

    Directory of Open Access Journals (Sweden)

    M. De La Calle

    2012-09-01

    Full Text Available During the last years the usage of 3D applications in GIS is becoming more popular. Since the appearance of Google Earth, users are familiarized with 3D environments. On the other hand, nowadays computers with 3D acceleration are common, broadband access is widespread and the public information that can be used in GIS clients that are able to use data from the Internet is constantly increasing. There are currently several libraries suitable for this kind of applications. Based on these facts, and using libraries that are already developed and connected to our own developments, we are working on the implementation of a real 3D GIS with analysis capabilities. Since a 3D GIS such as this can be very interesting for tasks like LiDAR or Laser Scanner point clouds rendering and analysis, special attention is given to get an optimal handling of very large data sets. Glob3 will be a multidimensional GIS in which 3D point clouds could be explored and analysed, even if they are consist of several million points.The latest addition to our visualization libraries is the development of a points cloud server that works regardless of the cloud's size. The server receives and processes petitions from a 3d client (for example glob3, but could be any other, such as one based on WebGL and delivers the data in the form of pre-processed tiles, depending on the required level of detail.

  4. Exposure of the Spanish population to radiation from natural sources

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  5. Computation of radiative image formation in isolated source and collimated irradiation problems

    Energy Technology Data Exchange (ETDEWEB)

    Li Hongshun [School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)]. E-mail: lihs_hust@yahoo.com.cn; Werther, Joachim [Chemical Engineering I, Technical University Hamburg-Harburg, Denickestrasse 15, 21071 Hamburg (Germany)

    2006-01-15

    Due to the ray effect, it is not suitable to employ the discrete ordinates method to calculate the radiation field and the image-formation process in radiative problems with isolated radiative sources (such as point and line sources, isolated medium or boundary source). In this paper, a hybrid method, named Monte Carlo-discrete ordinates method (Macadam) is developed. Firstly, the Monte Carlo method is used to calculate the emission process. Secondly, the discrete ordinates method is employed to calculate the scattering process, correspondingly, an alternative energy partitioning method is proposed to combine the above two conventional methods. Thirdly, the DOS+ISW algorithm (JQSRT, 2003, 78: 437-453) is used to calculate the image-formation process. Finally, the MCDOM is applied to computing the image formation of an endoscope, which was used to study the hydrodynamics of circulating fluidized beds (Powder Technology, 2001;114:71-83)

  6. Family of Quantum Sources for Improving Near Field Accuracy in Transducer Modeling by the Distributed Point Source Method

    Directory of Open Access Journals (Sweden)

    Dominique Placko

    2016-10-01

    Full Text Available The distributed point source method, or DPSM, developed in the last decade has been used for solving various engineering problems—such as elastic and electromagnetic wave propagation, electrostatic, and fluid flow problems. Based on a semi-analytical formulation, the DPSM solution is generally built by superimposing the point source solutions or Green’s functions. However, the DPSM solution can be also obtained by superimposing elemental solutions of volume sources having some source density called the equivalent source density (ESD. In earlier works mostly point sources were used. In this paper the DPSM formulation is modified to introduce a new kind of ESD, replacing the classical single point source by a family of point sources that are referred to as quantum sources. The proposed formulation with these quantum sources do not change the dimension of the global matrix to be inverted to solve the problem when compared with the classical point source-based DPSM formulation. To assess the performance of this new formulation, the ultrasonic field generated by a circular planer transducer was compared with the classical DPSM formulation and analytical solution. The results show a significant improvement in the near field computation.

  7. Dosimetric analysis of radiation sources for use dermatological lesions

    International Nuclear Information System (INIS)

    Tada, Ariane

    2010-01-01

    Skin lesions undergoing therapy with radiation sources may have different patterns of malignancy. Malignant lesions or cancer most commonly found in radiotherapy services are carcinomas. Radiation therapy in skin lesions is performed with low penetration beams and orthovoltage X-rays, electron beams and radioactive sources ( 192 Ir, 198 Au, e 90 Sr) arranged on a surface mold or in metal applicator. This study aims to analyze the therapeutic radiation dose profile produced by radiation sources used in skin lesions radiotherapy procedures . Experimental measurements for the analysis of dosimetric radiation sources were compared with calculations obtained from a computer system based on the Monte Carlo Method. Computational results had a good agreement with the experimental measurements. Experimental measurements and computational results by the MCNP4C code were both physically consistent as expected. These experimental measurements compared with calculations using the MCNP-4C code have been used to validate the calculations obtained by MCNP code and to provide a reliable medical application for each clinical case. (author)

  8. Source location of Jupiter's decametric radiation and UV aurora

    Science.gov (United States)

    Maeda, Koitiro; Carr, Thomas D.

    1989-01-01

    The source region of a component of Jovian Io-unrelated decametric radiation is inferred geometrically based on simultaneous observations from Voyager spacecraft and a ground-based observatory with the aid of a hollow cone beam model and model of the Jovian magnetic field. The results indicate that the sources of this component lie above the northern hemisphere, and on field lines that connect the Io plasma torus and the Jovian ionosphere in the so-called active sector. It is concluded that an interaction between the Io-torus plasma and the ionospheric plasma through a thin flux tube initiates the decametric radiation.

  9. ELBE Center for High-Power Radiation Sources

    Directory of Open Access Journals (Sweden)

    Peter Dr. Michel

    2016-01-01

    Full Text Available In the ELBE Center for High-Power Radiation Sources, the superconducting linear electron accelerator ELBE, serving  two free electron lasers, sources for intense coherent THz radiation, mono-energetic positrons, electrons, γ-rays, a neutron time-of-flight system as well as two synchronized ultra-short pulsed Petawatt laser systems are collocated. The characteristics of these beams make the ELBE center a unique research instrument for a variety of external users in fields ranging from material science over nuclear physics to cancer research, as well as scientists of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR.

  10. MCNP model for the many KE-Basin radiation sources

    International Nuclear Information System (INIS)

    Rittmann, P.D.

    1997-01-01

    This document presents a model for the location and strength of radiation sources in the accessible areas of KE-Basin which agrees well with data taken on a regular grid in September of 1996. This modelling work was requested to support dose rate reduction efforts in KE-Basin. Anticipated fuel removal activities require lower dose rates to minimize annual dose to workers. With this model, the effects of component cleanup or removal can be estimated in advance to evaluate their effectiveness. In addition, the sources contributing most to the radiation fields in a given location can be identified and dealt with

  11. The Advanced Light Source (ALS) Radiation Safety System

    International Nuclear Information System (INIS)

    Ritchie, A.; Oldfather, D.; Lindner, A.

    1993-05-01

    The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) is a 1.5 GeV synchrotron light source facility consisting of a 120 keV electron gun, 50 MeV linear accelerator, 1.5 Gev booster synchrotron, 200 meter circumference electron storage ring, and many photon beamline transport systems for research. The Radiation Safety System for the ALS has been designed and built with a primary goal of providing protection against inadvertent personnel exposure to gamma and neutron radiation and, secondarily, to enhance the electrical safety of select magnet power supplies

  12. Radiation induced segregation and point defects in binary copper alloys

    International Nuclear Information System (INIS)

    Monteiro, W.A.

    1984-01-01

    Considerable progress, both theoretical and experimental, has been made in establishing and understanding the influence of factors such as temperature, time, displacement rate dependence and the effect of initial solute misfit on radiation induced solute diffusion and segregation. During irradiation, the composition of the alloy changes locally, due to defect flux driven non-equilibrium segregation near sinks such as voids, external surfaces and grain boundaries. This change in composition could influence properties and phenomena such as ductility, corrosion resistance, stress corrosion cracking, sputtering and blistering of materials used in thermo-nuclear reactors. In this work, the effect of 1 MeV electron irradiation on the initiation and development of segregation and defect diffusion in binary copper alloys has been studied in situ, with the aid of a high voltage electron microscope. The binary copper alloys had Be, Pt and Sn as alloying elements which had atomic radii less than, similar and greater than that of copper, respectively. It has been observed that in a wide irradiation temperature range, stabilization and growth of dislocation loops took place in Cu-Sn and Cu-Pt alloys. Whereas in the Cu-Be alloy, radiation induced precipitates formed and transformed to the stable γ phase. (Author) [pt

  13. On the choice of working conditions for isotope radiation sources in irradiation plants

    International Nuclear Information System (INIS)

    Syrkus, N.P.; Breger, A.Kh.; Putilov, A.V.

    1975-01-01

    The problems of selecting an optimal regime for isotopic sources of radiation in powerful radiational installations depending on the costs, parameters of the radiational process (epsilon) and the radioactive isotope halflife are considered. When the radiation sources are simultaneusly replaced, then the optimal time of replacement of sources increases in the radiational installation with the radiation process parameter epsilon<0. Although the cost of a radiational product is lower during continuous replacement of radiation sources, the cost of products in the regime of simultaneous replacement of sources can be decreased, particularly, in the case of a secondary use of the radiactive sources

  14. The German radiation protection infrastructure with emphasis on the safety of radiation sources and radioactive material

    International Nuclear Information System (INIS)

    Czarwinski, R.; Weimer, G.

    2001-01-01

    Through federalism, Germany has a complicated but well functioning regulatory infrastructure for the safety and security of radiation sources based on a clear legal system. The main features of this infrastructure include the legal framework, the authorization and control systems and the responsibilities of different regulatory authorities, which this paper will describe. In connection with the legal framework, the provisions to control the import/export of radiation sources are briefly discussed and some information is given about the registries of sources. Protection and response measures related to unusual events concerning radiation sources, including orphan sources, will be cited. Also, the education and training of different target groups and punitive actions are touched upon in the paper. Conclusions will be drawn for future national and international actions. (author)

  15. Tokamak startup using point-source dc helicity injection.

    Science.gov (United States)

    Battaglia, D J; Bongard, M W; Fonck, R J; Redd, A J; Sontag, A C

    2009-06-05

    Startup of a 0.1 MA tokamak plasma is demonstrated on the ultralow aspect ratio Pegasus Toroidal Experiment using three localized, high-current density sources mounted near the outboard midplane. The injected open field current relaxes via helicity-conserving magnetic turbulence into a tokamaklike magnetic topology where the maximum sustained plasma current is determined by helicity balance and the requirements for magnetic relaxation.

  16. Romanian experience on safety and security of radiation sources

    International Nuclear Information System (INIS)

    Botgros, Madalina; Coroianu, Anton; Negreanu, Mircea

    2008-01-01

    Romania has established the first administrative structure for controlling the deployment of the nuclear activities in 1961 and the first Romanian nuclear law was published in 1974. In the present, it is in force the Law no. 111, published in 1996 and republished in 2003. Moreover, there are available facilities and services to the persons authorized to manage radioactive sources. The regulation for safety and security of radioactive sources was amended two times in order to implement the international recommendations for setting up the national system for accounting and control of radiation sources and to coordinate the recovery activities. As part of national control programme, the national inventory of sources and devices is updated permanently, when issuing a new authorization, when modifying an existing one, or when renewing an authorization system and records in the database. The government responsibility for the orphan sources is stated in the law on radioactive waste management and decommissioning fund. There is a protocol between CNCAN, Ministry of Internal and Ministry of Health and Family regarding the co-operation in the case of finding orphan sources. When a radiation source is spent, it becomes radioactive waste that has to be disposed off properly. Depending on the case, the holder of a spent source has the possibility either to return the radioactive source to its manufacturer for regeneration or to transfer it to the Radioactive Waste Treatment Facility. (author)

  17. Shielding design for a Cs-137 rod-type standard point source for well chamber constancy checks.

    Science.gov (United States)

    Sabet, Mahsheed; Cryer, David; Waterhouse, David

    2016-12-01

    Well type chambers are used for radioactive source calibrations in brachytherapy, but do not provide radiation shielding. Routine constancy checks on a well chamber are required between periodic secondary standard laboratory calibrations to ensure consistent device performance, and ultimately to ensure accurate patient dose delivery. In this work, a method is described to provide suitable shielding for a Cs-137 rod-type point source to enable use for constancy checks. A novel plunger-type shielded housing was designed and constructed for the Cs-137 source that when combined with a suitably shielded well-chamber container minimised user exposure during constancy checks. The designed shielding proved effective, and a constancy test routine was established and used for the past 16 months. The well chamber showed consistent performance (0.12 ± 0.18 % from the baseline) and no increased exposure was reported on users' radiation badges.

  18. Calculated neutron dose rates and flux densities from implantable californium-252 point and line sources.

    Science.gov (United States)

    Shapiro, A; Schwartz, B; Windham, J P; Kereiakes, J G

    1976-01-01

    The results of neutron-transport flux-density and dose rate calculations for implantable Californium-252 point and line sources in essentially infinite tissue-equivalent material are presented. The point-source flux densities were obtained from a discrete ordinates calculation, and the point dose rates were established by multiplying the flux densities by their appropriate kerma factors. Line-source dose rates were evaluated by integrating the point dose rates over the length of the line source. Dose-rate data are given within a 20 X 20-cm region from the source center for source lengths of 1.5, 2, and 3 cm. The dose rates established by these calculations showed good agreement with an independent Monte Carlo calculation. Detailed point-source flux-density data as a function of energy and position are also given.

  19. International basic safety standards for protecting against ionizing radiation and for the safety of radiation sources

    International Nuclear Information System (INIS)

    1996-01-01

    The purpose of the Standards is to establish basic requirements for protection against the risks associated with exposure to ionizing radiation (hereinafter termed radiation) and for the safety of radiation sources that may deliver such exposure. The Standards have been developed from widely accepted radiation protection and safety principles, such as those published in the Annals of the ICRP and the IAEA Safety Series. They are intended to ensure the safety of all types of radiation sources and, in doing so, to complement standards already developed for large and complex radiation sources, such as nuclear reactors and radioactive waste management facilities. For the sources, more specific standards, such as those issued by the IAEA, are typically needed to achieve acceptable levels of safety. As these more specific standards are generally consistent with the Standards, in complying with them, such more complex installations will also generally comply with the Standards. The Standards are limited to specifying basic requirements of radiation protection and safety, with some guidance on how to apply them. General guidance on applying some of the requirements is available in the publications of the Sponsoring Organizations and additional guidance will be developed as needed in the light of experience gained in the application of the Standards. Tabs

  20. Standard Syllabus for Postgraduate Educational Courses in Radiation Protection and the Safe use of Radiation Sources

    Energy Technology Data Exchange (ETDEWEB)

    Arias, C.; Biaggio, A.; Nasazzi, N.

    2004-07-01

    The International Atomic Energy Agency (IAEA) published the Standard Syllabus for Post Graduate Educational Courses in Radiation Protection and the Safety of Radiation Sources in 2002. Along more than two decades, Argentina has obtained valuable experience on building professional knowledge at postgraduate level in Radiation Protection and Nuclear Safety. Such experience made advisable to review the IAEA Standard Syllabus and to modify it accordingly. The whole content of the Standard Syllabus is included in the syllabus developed for the Argentinean Regional Post Graduate Course in Radiation Protection and Safety of Radiation Sources. But a few additional topics were incorporated and changes were introduced in the sequence of subjects. The paper describes those modifications and explains the pedagogic motivations that induce them. (Author) 3 refs.

  1. Analysis of polymer foil heaters as infrared radiation sources

    International Nuclear Information System (INIS)

    Witek, Krzysztof; Piotrowski, Tadeusz; Skwarek, Agata

    2012-01-01

    Infrared radiation as a heat source is used in many fields. In particular, the positive effect of far-infrared radiation on living organisms has been observed. This paper presents two technological solutions for infrared heater production using polymer-silver and polymer-carbon pastes screenprinted on foil substrates. The purpose of this work was the identification of polymer layers as a specific frequency range IR radiation sources. The characterization of the heaters was determined mainly by measurement of the surface temperature distribution using a thermovision camera and the spectral characteristics were determined using a special measuring system. Basic parameters obtained for both, polymer silver and polymer carbon heaters were similar and were as follows: power rating of 10–12 W/dm 2 , continuous working surface temperature of 80–90 °C, temperature coefficient of resistance (TCR) about +900 ppm/K for polymer-carbon heater and about +2000 ppm/K for polymer-silver, maximum radiation intensity in the wavelength range of 6–14 μm with top intensity at 8.5 μm and heating time about 20 min. For comparison purposes, commercial panel heater was tested. The results show that the characteristics of infrared polymer heaters are similar to the characteristics of the commercial heater, so they can be taken into consideration as the alternative infrared radiation sources.

  2. Ultrabroadband terahertz source and beamline based on coherent transition radiation

    Directory of Open Access Journals (Sweden)

    S. Casalbuoni

    2009-03-01

    Full Text Available Coherent transition radiation (CTR in the THz regime is an important diagnostic tool for analyzing the temporal structure of the ultrashort electron bunches needed in ultraviolet and x-ray free-electron lasers. It is also a powerful source of such radiation, covering an exceptionally broad frequency range from about 200 GHz to 100 THz. At the soft x-ray free-electron laser FLASH we have installed a beam transport channel for transition radiation (TR with the intention to guide a large fraction of the radiation to a laboratory outside the accelerator tunnel. The radiation is produced on a screen inside the ultrahigh vacuum beam pipe of the linac, coupled out through a diamond window and transported to the laboratory through an evacuated tube equipped with five focusing and four plane mirrors. The design of the beamline has been based on a thorough analysis of the generation of TR on metallic screens of limited size. The optical propagation of the radiation has been computed taking into account the effects of near-field (Fresnel diffraction. The theoretical description of the TR source is presented in the first part of the paper, while the design principles and the technical layout of the beamline are described in the second part. First experimental results demonstrate that the CTR beamline covers the specified frequency range and preserves the narrow time structure of CTR pulses emitted by short electron bunches.

  3. Management of Spent and Disused Radiation Sources - The Zambian Experience

    International Nuclear Information System (INIS)

    Chabala, F.

    2002-01-01

    Zambia like all other countries in the world is faced with environmental problems brought about by a variety of human activities. In Zambia the major environmental issues as identified by Nation Environmental Action Plan (NEAP) of 1994 are water pollution, poor sanitation, land degradation, air pollution, poor waste management, misuse of chemicals, wildlife depletion and deforestation. Zambian has been using a lot of radioactive materials in its various industries. The country has taken several projects with help of external partners. These partners however left these projects in the hands of the Zambians without developing their capacities to manage these radioactive sources. The Government recognized the need to manage these sources and passed legislation governing the management of radioactive materials. The first act of Parliament on Radiation Protection work was passed in 1975 to legislate the use of ionizing radiation. However, because of financial constraints the Country is facing, these regulations have remained unimplemented. Fortunately the international Community has been working in partnership with the Zambian Government in the Management of Radioactive Material. Therefore this paper will present the following aspects of radioactive waste management in Zambia: review Existing Legislation in Zambia regarding management of spent/radioactive sources; capacity building in the field of management of radioactive waste; management of spent and disused radiation sources; existing disposal systems in Zambia regarding spent/orphaned sources; existing stocks of radioactive sources in the Zambian industries

  4. Control of radiation sources and general regulations for accidental situations

    International Nuclear Information System (INIS)

    Slimani, A.

    1998-01-01

    In order to prevent accidents caused by application of radiation sources the Tunisian O.N.P.C. established straightforward strategy made up of 3 phases: prevention, planning and intervention. Civil Protection conducts prevention studies of all radiation sources by examining normal application conditions as well as possible accidental situations. It keeps up with scientific, technical and statistical aspects of radiation risks, elaborates specific plans and programs for intervention operations and cooperates with administrative and security services as well as international organisations. The O.N.P.C. established a model intervention plan based on observation (according to preliminary information), evaluation of the situation (according to the head of operation) intervention (specialized units) and post intervention (testing of personnel)

  5. 75 FR 19302 - Radiation Sources on Army Land

    Science.gov (United States)

    2010-04-14

    ... DEPARTMENT OF DEFENSE Department of the Army 32 CFR Part 655 RIN 0702-AA58 [Docket No. USA-2008-0001] Radiation Sources on Army Land AGENCY: Department of the Army, DoD. ACTION: Proposed rule; request for comments. SUMMARY: The Department of the Army proposes to revise its regulations concerning...

  6. arXiv Radiative symmetry breaking from interacting UV fixed points

    CERN Document Server

    Abel, Steven

    2017-09-28

    It is shown that the addition of positive mass-squared terms to asymptotically safe gauge-Yukawa theories with perturbative UV fixed points leads to calculable radiative symmetry breaking in the IR. This phenomenon, and the multiplicative running of the operators that lies behind it, is akin to the radiative symmetry breaking that occurs in the supersymmetric standard model.

  7. Plasma lasers (a strong source of coherent radiation in astrophysics)

    Science.gov (United States)

    Papadopoulos, K.

    1981-01-01

    The generation of electromagnetic radiation from the free energy available in electron streams is discussed. The fundamental principles involved in a particular class of coherent plasma radiation sources, i.e., plasma lasers, are reviewed, focusing on three wave coupling, nonlinear parametric instabilities, and negative energy waves. The simplest case of plasma lasers, that of an unmagnetized plasma containing a finite level of density fluctuations and electrons streaming with respect to the ions, is dealt with. A much more complicated application of plasma lasers to the case of auroral kilometric radiation is then examined. The concept of free electron lasers, including the role of relativistic scattering, is elucidated. Important problems involving the escape of the excited radiation from its generation region, effects due to plasma shielding and nonlinear limits, are brought out.

  8. Overview in Argentina on spent/disused radiation sources

    International Nuclear Information System (INIS)

    Lavalle, M.B.

    2001-01-01

    Argentine nuclear activities have begun since about 1950. Since those days the peaceful applications of nuclear energy have been developed and together with then radioactive wastes have taken more and more relevance day by day. To deal with this special subject the Radioactive Waste Management Programme (RWMP) has been established. Spent/disused radiation sources are a very important task to consider in the management of radioactive waste. A great number of sources have been received along these years by the RWMP. Different sources categories handled together with their figures and radionuclide activities will be presented. Also described will be the steps that have to be followed by the users/owners of spent/disused radiation sources to transfer them to the RWMP. Once the sources are in the RWMP custody, they can be stored or they can be conditioned in order to be stored in an interim storage or disposed of. It is shown how the different sources are managed, taking into account the radionuclide's half life, its activity and the available facilities. Besides a record-keeping system for tracking all spent/disused radiation sources has been developed. It consists on a computerized database that contains essential information about the sources as well as the whole radioactive wastes managed by the RWMP. The main objective of the waste management registry-database system is to collect, identify, process and follow the related information about the radioactive wastes among al the management steps. It is also able to calculate the actualized activity inventory for the storage and final disposal facilities. In order to implement this system, it was necessary to write the related technical documentation. These documents established the radioactive waste acceptance requirements, that together with others integrates the Quality Assurance System applied to the radioactive waste management. Regarding the disused sources little could be done. They are stored in an appropriate

  9. Small compact pulsed electron source for radiation technologies

    International Nuclear Information System (INIS)

    Korenev, Sergey

    2002-01-01

    The small compact pulsed electron source for radiation technologies is considered in the report. The electron source consists of pulsed high voltage Marx generator and vacuum diode with explosive emission cathode. The main parameters of electron source are next: kinetic energy is 100-150 keV, beam current is 5-200 A and pulse duration is 100-400 nsec. The distribution of absorbed doses in irradiated materials is considered. The physical feasibility of pulsed low energy electron beam for applications is considered

  10. Training in radiation protection and the safe use of radiation sources

    International Nuclear Information System (INIS)

    2001-01-01

    The need for education and training in the various disciplines of radiation protection has long been recognized by the IAEA, the International Labour Organization (ILO), the United Nations Educational, Scientific and Cultural Organization, the World Health Organization and the Pan American Health Organization (PAHO). This need has been partially met through the many training courses undertaken by these organizations, either individually or in collaboration. The IAEA has assisted developing Member States in the training of specialists in radiation protection and safety through its organized educational and specialized training courses, workshops, seminars, fellowships and scientific visits. Training is an important means of promoting safety culture and enhancing the level of competence of personnel involved in radiation protection activities, and has acquired a place in the IAEA's programme accordingly. For example, the IAEA Post-graduate Educational Course in Radiation Protection and the Safe Use of Radiation Sources is regularly offered in countries around the world, and has been provided in Arabic, English, French, Spanish and Russian. The training provided by the IAEA is primarily aimed at regulators, professionals working in radiation protection and those responsible for the development of training programmes in their own countries. The importance of adequate and appropriate training for all those working with ionizing radiation has been highlighted by the results of the IAEA's investigations of radiological accidents. A significant contributory factor in a number of the accidents has been a lack of adequate training, which gave rise to errors with serious consequences. This report provides assistance in organizing training and complying with the requirements on training of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS). The previous version of this report. Technical Reports

  11. [A landscape ecological approach for urban non-point source pollution control].

    Science.gov (United States)

    Guo, Qinghai; Ma, Keming; Zhao, Jingzhu; Yang, Liu; Yin, Chengqing

    2005-05-01

    Urban non-point source pollution is a new problem appeared with the speeding development of urbanization. The particularity of urban land use and the increase of impervious surface area make urban non-point source pollution differ from agricultural non-point source pollution, and more difficult to control. Best Management Practices (BMPs) are the effective practices commonly applied in controlling urban non-point source pollution, mainly adopting local repairing practices to control the pollutants in surface runoff. Because of the close relationship between urban land use patterns and non-point source pollution, it would be rational to combine the landscape ecological planning with local BMPs to control the urban non-point source pollution, which needs, firstly, analyzing and evaluating the influence of landscape structure on water-bodies, pollution sources and pollutant removal processes to define the relationships between landscape spatial pattern and non-point source pollution and to decide the key polluted fields, and secondly, adjusting inherent landscape structures or/and joining new landscape factors to form new landscape pattern, and combining landscape planning and management through applying BMPs into planning to improve urban landscape heterogeneity and to control urban non-point source pollution.

  12. Nuisance Source Population Modeling for Radiation Detection System Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sokkappa, P; Lange, D; Nelson, K; Wheeler, R

    2009-10-05

    A major challenge facing the prospective deployment of radiation detection systems for homeland security applications is the discrimination of radiological or nuclear 'threat sources' from radioactive, but benign, 'nuisance sources'. Common examples of such nuisance sources include naturally occurring radioactive material (NORM), medical patients who have received radioactive drugs for either diagnostics or treatment, and industrial sources. A sensitive detector that cannot distinguish between 'threat' and 'benign' classes will generate false positives which, if sufficiently frequent, will preclude it from being operationally deployed. In this report, we describe a first-principles physics-based modeling approach that is used to approximate the physical properties and corresponding gamma ray spectral signatures of real nuisance sources. Specific models are proposed for the three nuisance source classes - NORM, medical and industrial. The models can be validated against measured data - that is, energy spectra generated with the model can be compared to actual nuisance source data. We show by example how this is done for NORM and medical sources, using data sets obtained from spectroscopic detector deployments for cargo container screening and urban area traffic screening, respectively. In addition to capturing the range of radioactive signatures of individual nuisance sources, a nuisance source population model must generate sources with a frequency of occurrence consistent with that found in actual movement of goods and people. Measured radiation detection data can indicate these frequencies, but, at present, such data are available only for a very limited set of locations and time periods. In this report, we make more general estimates of frequencies for NORM and medical sources using a range of data sources such as shipping manifests and medical treatment statistics. We also identify potential data sources for industrial

  13. Characterization of the radiation from a low-energy X-pinch source

    Science.gov (United States)

    Christou, Christos; Choi, Peter

    1991-12-01

    The explosion of a single wire with a high current pulse has long been established as an excellent source of x-ray radiation. However, experimental analysis of single wire explosions shows that the radiation is emitted from an inhomogeneous plasma consisting of high-density high-energy emitting points located randomly in a low density background column. The X- pinch, in which two or more crossed wires are exploded by a large current pulse driven by a low inductance source, is a good source of soft x-ray radiation in the energy range of 100 eV to 10 keV. The geometry of the crossed wire load ensures that the plasma emitting the bulk of the harder radiation is reproducibly located at the crossing point of the wires. This renders the source ideal for applications such as x-ray microscopy and lithography. Previous work on X- pinches has been carried out using elaborate high-voltage pulsed power generators delivering a brief high current pulse. Results are presented here of a first comprehensive study of X-pinch discharges driven by a low energy (4 kJ), low voltage (30 kV) 9 (mu) F capacitor bank. X- ray emission from X-pinches made from a variety of wires of different sizes and materials is characterized and compared with x-ray emission from single wire discharges. Radiation output is measured for different spectral regimes and information is presented concerning both the spatial and temporal emission of the radiation. Conditions for optimal soft x-ray yield on such low power machines are established.

  14. Research sources of ionizing radiation based on transplutonium elements

    Science.gov (United States)

    Radchenko, V. M.; Ryabinin, M. A.

    2010-03-01

    Scientific and technical demand stimulates an extension of the practical implementation field of TPE, requirements to their ecological safety calling for the development of such materials which could be most resistant to the environment and most suitable for the production of a wide range of sources different in their application and design. Such materials can involve pure metals of transplutonium elements and their alloys with metals of platinum group as well as their chemically stable compounds (such as silicides, carbides etc.) At SSC RIAR production processes of sources of different type and application have been implemented. Examples of the most recent developments of the sources are presented below. Presented is the analysis of the current state of issues related to designing, production and application of radionuclide research sources based on transplutonium elements. Examples of the development of the most up-to-date sources of alpha-, gamma- and neutron radiation and also fission ones are considered.

  15. Present situation of regulatory control of radiation sources in Cuba

    International Nuclear Information System (INIS)

    Fernandez Gomez, U.

    2001-01-01

    The report explains the basis for an effective regulatory control and in particular refers to the system established in Cuba for such purposes. Reference is made to the new Decree-Law No. 207 'On the Use of Nuclear Energy' and the main topics it covers and to the 'Rules for Authorization of Practices Involving the use of Radiation Sources' which have been in force since 1998. Following it, the report illustrates the existing Cuban system of notification, registration and licensing, and of inspection and enforcement, including information of the established classification of radiation practices in the country. (author)

  16. Definition of loss-of-coolant accident radiation source

    International Nuclear Information System (INIS)

    1978-02-01

    Meaningful qualification testing of nuclear reactor components requires a knowledge of the radiation fields expected in a loss-of-coolant accident (LOCA). The overall objective of this program is to define the LOCA source terms and compare these with the output of various simulators employed for radiation qualification testing. The basis for comparison will be the energy deposition in a model reactor component. The results of the calculations are presented and some interpretation of the results given. The energy release rates and spectra were validated by comparison with other calculations using different codes since experimental data appropriate to these calculations do not exist

  17. The Central Point Source in G76. 9+ 1.0

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We describe the serendipitous discovery of a very steep-spectrum radio point source in low-frequency Giant Metrewave Radio Telescope (GMRT) images of the supernova remnant (SNR) G76.9+1.0. The steep spectrum, as well as the location of the point source near the centre of this SNR confirm that this ...

  18. A point source solution for unidirectional flow of a viscoelastic fluid

    International Nuclear Information System (INIS)

    Momoniat, E.

    2008-01-01

    A Fourier point source solution modelling the effect of an impulse on a viscoelastic fluid of second-grade is investigated. By examining the second-moment of a Fourier point source solution we show that for Dt >1 the fluid undergoes classical diffusion indicating that the viscous properties of the fluid are dominating

  19. Programmes and Systems for Source and Environmental Radiation Monitoring

    International Nuclear Information System (INIS)

    2010-01-01

    The discharge of radionuclides to the atmosphere and aquatic environments is a legitimate practice in the nuclear and other industries, hospitals and research. Where appropriate, monitoring of the discharges and of relevant environmental media is an essential regulatory requirement in order to ensure appropriate radiation protection of the public. Such monitoring provides information on the actual amounts of radioactive material discharged and the radionuclide concentrations in the environment, and is needed to demonstrate compliance with authorized limits, to assess the radiation exposure of members of the public and to provide data to aid in the optimization of radiation protection. Uncontrolled releases of radionuclides to the atmosphere and aquatic environments may occur as a result of a nuclear or radiological accident. Again, monitoring at the source of the release and of the environment is necessary. In this case, monitoring is used both to assess the radiation exposure of members of the public and to determine the actions necessary for public protection, including longer term countermeasures. Source and environmental monitoring associated with the release of radionuclides to the environment is the subject of a number of IAEA Safety Standards, particularly IAEA Safety Standard RS-G-1.8 (Environmental and Source Monitoring for Purposes of Radiation Protection). This publication is intended to complement this Safety Guide and, by so doing, replaces Safety Series No. 41 (Objectives and Design of Environmental Monitoring Programmes for Radioactive Contaminants) and Safety Series No. 46 (Monitoring of Airborne and Liquid Radioactive Releases from Nuclear Facilities to the Environment). Like Safety Standard RS-G-1.8, this Safety Report deals with monitoring at the source and in the environment associated with authorized releases of radionuclides to the environment. It also deals with the general issues of emergency monitoring during and in the aftermath of an

  20. XID II: STATISTICAL CROSS-ASSOCIATION OF ROSAT BRIGHT SOURCE CATALOG X-RAY SOURCES WITH 2MASS POINT SOURCE CATALOG NEAR-INFRARED SOURCES

    International Nuclear Information System (INIS)

    Haakonsen, Christian Bernt; Rutledge, Robert E.

    2009-01-01

    The 18,806 ROSAT All Sky Survey Bright Source Catalog (RASS/BSC) X-ray sources are quantitatively cross-associated with near-infrared (NIR) sources from the Two Micron All Sky Survey Point Source Catalog (2MASS/PSC). An association catalog is presented, listing the most likely counterpart for each RASS/BSC source, the probability P id that the NIR source and X-ray source are uniquely associated, and the probability P no-id that none of the 2MASS/PSC sources are associated with the X-ray source. The catalog includes 3853 high quality (P id >0.98) X-ray-NIR matches, 2280 medium quality (0.98 ≥ P id >0.9) matches, and 4153 low quality (0.9 ≥ P id >0.5) matches. Of the high quality matches, 1418 are associations that are not listed in the SIMBAD database, and for which no high quality match with a USNO-A2 optical source was presented for the RASS/BSC source in previous work. The present work offers a significant number of new associations with RASS/BSC objects that will require optical/NIR spectroscopy for classification. For example, of the 6133 P id >0.9 2MASS/PSC counterparts presented in the association catalog, 2411 have no classification listed in the SIMBAD database. These 2MASS/PSC sources will likely include scientifically useful examples of known source classes of X-ray emitters (white dwarfs, coronally active stars, active galactic nuclei), but may also contain previously unknown source classes. It is determined that all coronally active stars in the RASS/BSC should have a counterpart in the 2MASS/PSC, and that the unique association of these RASS/BSC sources with their NIR counterparts thus is confusion limited.

  1. Simultaneous Determination of Source Wavelet and Velocity Profile Using Impulsive Point-Source Reflections from a Layered Fluid

    National Research Council Canada - National Science Library

    Bube, K; Lailly, P; Sacks, P; Santosa, F; Symes, W. W

    1987-01-01

    .... We show that a quasi-impulsive, isotropic point source may be recovered simultaneously with the velocity profile from reflection data over a layered fluid, in linear (perturbation) approximation...

  2. Investigation of Light-Emitting Diode (LED) Point Light Source Color Visibility against Complex Multicolored Backgrounds

    Science.gov (United States)

    2017-11-01

    ARL-TR-8214 ● NOV 2017 US Army Research Laboratory Investigation of Light-Emitting Diode (LED) Point Light Source Color...ARL-TR-8214 ● NOV 2017 US Army Research Laboratory Investigation of Light-Emitting Diode (LED) Point Light Source Color Visibility against...instructions, searching existing data sources , gathering and maintaining the data needed, and completing and reviewing the collection information. Send

  3. Postgraduate educational course in radiation protection and the safety of radiation sources. Standard syllabus

    International Nuclear Information System (INIS)

    2004-01-01

    The aim of the Postgraduate Educational Course in Radiation Protection and the Safety of Radiation Sources is to meet the needs of professionals at graduate level, or the equivalent, for initial training to acquire a sound basis in radiation protection and the safety of radiation sources. The course also aims to provide the necessary basic tools for those who will become trainers in radiation protection and in the safe use of radiation sources in their countries. It is designed to provide both theoretical and practical training in the multidisciplinary scientific and/or technical bases of international recommendations and standards on radiation protection and their implementation. The participants should have had a formal education to a level equivalent to a university degree in the physical, chemical or life sciences or engineering and should have been selected to work in the field of radiation protection and the safe use of radiation sources in their countries. The present revision of the Standard Syllabus takes into account the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), IAEA Safety Series No. 115 (1996) and recommendations of related Safety Guides, as well as experience gained from the Postgraduate Educational Course on Radiation Protection and Safety of Radiation Sources held in several regions in recent years. The general aim of the course, as mentioned, is the same. Some of the improvements in the present version are as follows: The learning objective of each part is specified. The prerequisites for each part are specified. The structure of the syllabus has been changed: the parts on Principles of Radiation Protection and on Regulatory Control were moved ahead of Dose Assessment and after Biological Effects of Radiation. The part on the interface with nuclear safety was dropped and a module on radiation protection in nuclear power plants has been included. A

  4. Postgraduate educational course in radiation protection and the safety of radiation sources. Standard syllabus

    International Nuclear Information System (INIS)

    2003-01-01

    The aim of the Postgraduate Educational Course in Radiation Protection and the Safety of Radiation Sources is to meet the needs of professionals at graduate level, or the equivalent, for initial training to acquire a sound basis in radiation protection and the safety of radiation sources. The course also aims to provide the necessary basic tools for those who will become trainers in radiation protection and in the safe use of radiation sources in their countries. It is designed to provide both theoretical and practical training in the multidisciplinary scientific and/or technical bases of international recommendations and standards on radiation protection and their implementation. The participants should have had a formal education to a level equivalent to a university degree in the physical, chemical or life sciences or engineering and should have been selected to work in the field of radiation protection and the safe use of radiation sources in their countries. The present revision of the Standard Syllabus takes into account the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), IAEA Safety Series No. 115 (1996) and recommendations of related Safety Guides, as well as experience gained from the Postgraduate Educational Course on Radiation Protection and Safety of Radiation Sources held in several regions in recent years. The general aim of the course, as mentioned, is the same. Some of the improvements in the present version are as follows: The learning objective of each part is specified. The prerequisites for each part are specified. The structure of the syllabus has been changed: the parts on Principles of Radiation Protection and on Regulatory Control were moved ahead of Dose Assessment and after Biological Effects of Radiation. The part on the interface with nuclear safety was dropped and a module on radiation protection in nuclear power plants has been included. A

  5. Postgraduate educational course in radiation protection and the safety of radiation sources. Standard syllabus

    International Nuclear Information System (INIS)

    2002-01-01

    The aim of the Postgraduate Educational Course in Radiation Protection and the Safety of Radiation Sources is to meet the needs of professionals at graduate level, or the equivalent, for initial training to acquire a sound basis in radiation protection and the safety of radiation sources. The course also aims to provide the necessary basic tools for those who will become trainers in radiation protection and in the safe use of radiation sources in their countries. It is designed to provide both theoretical and practical training in the multidisciplinary scientific and/or technical bases of international recommendations and standards on radiation protection and their implementation. The participants should have had a formal education to a level equivalent to a university degree in the physical, chemical or life sciences or engineering and should have been selected to work in the field of radiation protection and the safe use of radiation sources in their countries. The present revision of the Standard Syllabus takes into account the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), IAEA Safety Series No. 115 (1996) and recommendations of related Safety Guides, as well as experience gained from the Postgraduate Educational Course on Radiation Protection and Safety of Radiation Sources held in several regions in recent years. The general aim of the course, as mentioned, is the same. Some of the improvements in the present version are as follows: The learning objective of each part is specified. The prerequisites for each part are specified. The structure of the syllabus has been changed: the parts on Principles of Radiation Protection and on Regulatory Control were moved ahead of Dose Assessment and after Biological Effects of Radiation. The part on the interface with nuclear safety was dropped and a module on radiation protection in nuclear power plants has been included. A

  6. Radiological protection issues in endovascular use of radiation sources

    International Nuclear Information System (INIS)

    2006-02-01

    The use of radiation from radioactive materials for cancer treatment is well established. However, examples of uses of radiation therapy for benign conditions have been limited. Placing a radioactive source in the blood vessel so as to irradiate the surrounding inner periphery of the vessel has been attempted in recent years to prevent restenosis after percutaneous coronary and peripheral interventions. This kind of endovascular application provides treatment options that are less invasive for various vascular conditions compared with open surgery. As a part of the International Atomic Energy Agency's (IAEA) function for providing for application of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) that were jointly sponsored by the IAEA, FAO, ILO, OECD/NEA, PAHO and WHO, the IAEA planned a coordinated research project (CRP) that was to start in 2002 on radiological protection problems in endovascular use of radiation sources. However, as experts soon realized that the interest in this modality was waning, the CRP was not initiated. Nevertheless, it was felt that it would be appropriate to compile the information available on radiological protection problems observed so far and their possible solutions. This work was seen as part of a broader IAEA programme that covered accident prevention in radiotherapy. Publications on this topic have included, inter alia, Lessons Learned from Accidental Exposures in Radiotherapy (Safety Reports Series No. 17); Accidental Overexposure of Radiotherapy Patients in Bialystok; Investigation of an Accidental Exposure of Radiotherapy Patients in Panama; Accidental Overexposure of Radiotherapy Patients in San Jose, Costa Rica; and Investigation of an Accidental Exposure of Radiotherapy Patients in Poland. Keeping in mind that endovascular applications involve specialists such as cardiologists, angiologists and surgeons, all of whom might not have a

  7. Science experiments via telepresence at a synchrotron radiation source facility

    International Nuclear Information System (INIS)

    Warren, J. E.; Diakun, G.; Bushnell-Wye, G.; Fisher, S.; Thalal, A.; Helliwell, M.; Helliwell, J. R.

    2008-01-01

    The application of a turnkey communication system for telepresence at station 9.8 of the Synchrotron Radiation Source, Daresbury, is described and demonstrated, including its use for inter-continental classroom instruction and user training. Station 9.8 is one of the most oversubscribed and high-throughput stations at the Synchrotron Radiation Source, Daresbury, whereby awarded experimental time is limited, data collections last normally no longer than an hour, user changeover is normally every 24 h, and familiarity with the station systems can be low. Therefore time lost owing to technical failures on the station has a dramatic impact on productivity. To provide 24 h support, the application of a turnkey communication system has been implemented, and is described along with additional applications including its use for inter-continental classroom instruction, user training and remote participation

  8. Regulatory control of radiation sources in the Philippines

    International Nuclear Information System (INIS)

    Daroy, Rosita R.

    1995-01-01

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI's regulatory functions are presented. (author)

  9. Sources and effects of ionizing radiation. UNSCEAR 2000 report to the General Assembly, with scientific annexes. Volume I: Sources

    International Nuclear Information System (INIS)

    2000-01-01

    Over the past few years the United Nations Scientific Committee on the effects of Atomic Radiation has undertaken a broad review of the sources and effects of ionizing radiation. In the present report, the Committee, drawing on the main conclusions of its scientific assessment summarizes the developments in radiation science in the years leading up to the next millennium. It covers the following: the effects of radiation exposure; levels of radiation exposure; radiological consequences of the Chernobyl accident; sources of radiation exposure including natural exposures, man-made environmental exposures, medical and occupational exposures; radiation associated cancer. This volume includes five Annexes covering: dose assessment methodologies; exposure from natural sources; exposures to the public from man-made sources of radiation and occupational radiation exposures

  10. Medical and industrial radiation sources as radiological weapons

    International Nuclear Information System (INIS)

    Bielefeld, T.; Fischer, H.W.

    2006-01-01

    The execution of attacks with radiological weapons are well within the capabilities of both local terrorist groups and transnational terrorist networks. In a research project, plausible attack scenarios have been developed, based on medical and industrial radioactive sources widely used in Germany. Special emphasis was put on how such sources could be obtained applying criminal tactics. To this end, working procedures in hospitals and companies have been analyzed. Furthermore, by means of simulations, the consequences of a terrorist attack using such sources were estimated. None of the scenarios we investigated led to doses at the site of the explosion which might cause acute radiation effects. However, in some scenarios, an attack would result in the necessity of a potentially very costly clean-up of large urban areas. Therefore, improvements in sources security are recommended. (orig.)

  11. Experiments planned to be made with the synchrotron radiation source

    International Nuclear Information System (INIS)

    Matz, W.

    1993-01-01

    For this working meeting, various research groups from the Land Sachsen and from the neighbouring countries Poland and the Czech Republic have been invited in order to present their materials research programmes or task-specific experiments intended to be carried out with the synchrotron radiation source to be installed in the near future. The proceedings volume in hand presents the discussion papers, which have been directly reproduced from the original foils. (orig.) [de

  12. Limitation of population's irradiation by natural sources of ionizing radiation

    International Nuclear Information System (INIS)

    Krisyuk, Eh.M.

    1989-01-01

    Review of works devoted to evaluating the human irradiation doses at the expense of the main sources of ionizing radiation, is given. It is shown that the human irradiation doses at the expense of DDP can be reduced 10 times and more. However to realize such measures it is necessary to study the efficiency and determine the cost of various protective activities as well as to develop the criteria of their realization necessity

  13. The feasibility of 10 keV X-ray as radiation source in total dose response radiation test

    International Nuclear Information System (INIS)

    Li Ruoyu; Li Bin; Luo Hongwei; Shi Qian

    2005-01-01

    The standard radiation source utilized in traditional total dose response radiation test is 60 Co, which is environment-threatening. X-rays, as a new radiation source, has the advantages such as safety, precise control of dose rate, strong intensity, possibility of wafer-level test or even on-line test, which greatly reduce cost for package, test and transportation. This paper discussed the feasibility of X-rays replacing 60 Co as the radiation source, based on the radiation mechanism and the effects of radiation on gate oxide. (authors)

  14. Study on radiation dose in single-source and triple-source helical cone-beam scanning

    International Nuclear Information System (INIS)

    Lv Yang; Zhao Jun; Zhuang Tiange; Chen Kemin

    2008-01-01

    In this work we discuss the radiation area of helical cone-beam scanning and present the formulae to calculate the radiation dosage of single-source and triple-source helical cone-beam scanning. The results reveal that the radiation dose of triple-source helical cone-beam scanning is equal to that of single-source helical cone-beam scanning. (authors)

  15. Sulfate Aerosol in the Arctic: Source Attribution and Radiative Forcing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Wang, Hailong [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Smith, Steven J. [Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park MD USA; Easter, Richard C. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Rasch, Philip J. [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA

    2018-02-08

    Source attributions of Arctic sulfate and its direct radiative effect for 2010–2014 are quantified in this study using the Community Earth System Model (CESM) equipped with an explicit sulfur source-tagging technique. Regions that have high emissions and/or are near/within the Arctic present relatively large contributions to Arctic sulfate burden, with the largest contribution from sources in East Asia (27%). East Asia and South Asia together have the largest contributions to Arctic sulfate concentrations at 9–12 km, whereas sources within or near the Arctic account largely below 2 km. For remote sources with strong emissions, their contributions to Arctic sulfate burden are primarily driven by meteorology, while contributions of sources within or near the Arctic are dominated by their emission strength. The sulfate direct radiative effect (DRE) is –0.080 W m-2 at the Arctic surface, offsetting the net warming effect from the combination of in-snow heating and DRE cooling from black carbon. East Asia, Arctic local and Russia/Belarus/Ukraine sources contribute –0.017, –0.016 and –0.014 W m-2, respectively, to Arctic sulfate DRE. A 20% reduction in anthropogenic SO2 emissions leads to a net increase of +0.013 W m-2 forcing at the Arctic surface. These results indicate that a joint reduction in BC emissions could prevent possible Arctic warming from future reductions in SO2 emissions. Sulfate DRE efficiency calculations suggest that short transport pathways together with meteorology favoring long sulfate lifetimes make certain sources more efficient in influencing the Arctic sulfate DRE.

  16. Fast radio burst source properties and curvature radiation model

    Science.gov (United States)

    Kumar, Pawan; Lu, Wenbin; Bhattacharya, Mukul

    2017-07-01

    We use the observed properties of fast radio bursts (FRBs) and a number of general physical considerations to provide a broad-brush model for the physical properties of FRB sources and the radiation mechanism. We show that the magnetic field in the source region should be at least 1014 G. This strong field is required to ensure that the electrons have sufficiently high ground state Landau energy so that particle collisions, instabilities and strong electromagnetic fields associated with the FRB radiation do not perturb electrons' motion in the direction transverse to the magnetic field and destroy their coherent motion; coherence is required by the high observed brightness temperature of FRB radiation. The electric field in the source region required to sustain particle motion for a wave period is estimated to be of the order of 1011 esu. These requirements suggest that FRBs are produced near the surface of magnetars perhaps via forced reconnection of magnetic fields to produce episodic, repeated, outbursts. The beaming-corrected energy release in these bursts is estimated to be about 1036 erg, whereas the total energy in the magnetic field is at least ˜1045 erg. We provide a number of predictions for this model which can be tested by future observations. One of which is that short duration FRB-like bursts should exist at much higher frequencies, possibly up to optical.

  17. Risks and hazards from conventional and radiation sources

    International Nuclear Information System (INIS)

    Iyer, P.S.; Ganguly, A.K.

    1978-01-01

    Beneficial uses of radioisotopes in medicine, industry, agriculture and research are discussed. In absence of adequate safety precautions, uses of radiation may also result in harmful biological effects or genetic effects. Radiation risks and hazards are evaluated by comparing with other risks and hazards which are routinely encountered. The risk of fatality per year by various causes in U.S.A. is given. It is stated with examples and observations that some of the routine habits and necessities and minor luxuries are more risky than radiation risks. Countrywide radiation safety program in India by the Department of Atomic Energy is described in brief. Data are given to show that the risks from radiation are much lower in comparison with many conventional sources. More efficient equipment such as image intensifier is recommended to help to reduce the patient dose. It is stated that caution has to be exercised while handling the X-ray machines which may be harmful not only to patients but to doctors also. As regards, nuclear medicine, it is mentioned that though it is a fast expanding speciality in India, the number of procedures carried out in various centres is small as compared to U.S.A. and France. Some instances are given to show the consequences of the ignorance of the radiation hazards in operating machines in X-ray and gamma ray beam therapy facilities. A survey made by DRP, BARC revealed that some research laboratories lacked basic radiation protection requirements in using X-ray crystallography or analytical equipment. (B.G.W.)

  18. Distinguishing dark matter from unresolved point sources in the Inner Galaxy with photon statistics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Samuel K. [Princeton Center for Theoretical Science, Princeton University, 400 Jadwin Hall, Princeton, NJ, 08544 (United States); Lisanti, Mariangela [Department of Physics, Princeton University, Jadwin Hall, Princeton, NJ, 08544 (United States); Safdi, Benjamin R., E-mail: samuelkl@princeton.edu, E-mail: mlisanti@princeton.edu, E-mail: bsafdi@princeton.edu [Center for Theoretical Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., 6-304, Cambridge, MA, 02139 (United States)

    2015-05-01

    Data from the Fermi Large Area Telescope suggests that there is an extended excess of GeV gamma-ray photons in the Inner Galaxy. Identifying potential astrophysical sources that contribute to this excess is an important step in verifying whether the signal originates from annihilating dark matter. In this paper, we focus on the potential contribution of unresolved point sources, such as millisecond pulsars (MSPs). We propose that the statistics of the photons—in particular, the flux probability density function (PDF) of the photon counts below the point-source detection threshold—can potentially distinguish between the dark-matter and point-source interpretations. We calculate the flux PDF via the method of generating functions for these two models of the excess. Working in the framework of Bayesian model comparison, we then demonstrate that the flux PDF can potentially provide evidence for an unresolved MSP-like point-source population.

  19. Inference of Unresolved Point Sources at High Galactic Latitudes Using Probabilistic Catalogs

    Science.gov (United States)

    Daylan, Tansu; Portillo, Stephen K. N.; Finkbeiner, Douglas P.

    2017-04-01

    The detection of point sources in images is a fundamental operation in astrophysics, and is crucial for constraining population models of the underlying point sources or characterizing the background emission. Standard techniques fall short in the crowded-field limit, losing sensitivity to faint sources and failing to track their covariance with close neighbors. We construct a Bayesian framework to perform inference of faint or overlapping point sources. The method involves probabilistic cataloging, where samples are taken from the posterior probability distribution of catalogs consistent with an observed photon count map. In order to validate our method, we sample random catalogs of the gamma-ray sky in the direction of the North Galactic Pole (NGP) by binning the data in energy and point-spread function classes. Using three energy bins spanning 0.3-1, 1-3, and 3-10 GeV, we identify {270}-10+30 point sources inside a 40^\\circ × 40^\\circ region around the NGP above our point-source inclusion limit of 3× {10}-11 cm-2 s-1 sr-1 GeV-1 at the 1-3 GeV energy bin. Modeling the flux distribution as a power law, we infer the slope to be -{1.92}-0.05+0.07 and estimate the contribution of point sources to the total emission as {18}-2+2%. These uncertainties in the flux distribution are fully marginalized over the number as well as the spatial and spectral properties of the unresolved point sources. This marginalization allows a robust test of whether the apparently isotropic emission in an image is due to unresolved point sources or of truly diffuse origin.

  20. Fabrication of radiation sources for educational purposes from chemical fertilizers using compressing and forming method

    International Nuclear Information System (INIS)

    Kawano, Takao

    2008-01-01

    Chemical fertilizers contain potassium, which is composed of a small amount of naturally occurring potassium-40. The potassium-40 radionuclide emits beta and gamma radiation. Three brands of chemical fertilizer were used to fabricate disk-shaped radiation sources and the fabricated radiation sources were examined for applicability to an educational radiation course. In the examination, tests to determine dependence of count rate on distance, shielding thickness, and shielding materials were conducted using the radiation sources. Results showed that radiation sources fabricated from the three brands of chemical fertilizer were equivalent for explaining radiation characteristics, particularly those related to the dependence of radiation strength on distance and shielding thickness. The relation between shielding effect and mass density can be explained qualitatively. Thus, chemical fertilizer radiation sources can be a useful teaching aid for educational courses to better promote understanding of radiation characteristics and the principles of radiation protection. (author)

  1. Regulatory control of radiation sources and radioactive materials in Ireland

    International Nuclear Information System (INIS)

    McGarry, A.T.; Fenton, D.; O'Flaherty, T.

    2001-01-01

    The primary legislation governing safety in uses of ionizing radiation in Ireland is the Radiological Protection Act, 1991. This Act provided for the establishment in 1992 of the Radiological Protection Institute of Ireland, and gives the Institute the functions and powers which enable it to be the regulatory body for all matters relating to ionizing radiation. A Ministerial Order made under the Act in 2000 consolidates previous regulations and, in particular, provides for the implementation in Irish law of the 1996 European Union Directive which lays down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionizing radiation. Under the legislation, the custody, use and a number of other activities involving radioactive substances and irradiating apparatus require a licence issued by the Institute. Currently some 1260 licences are in force. Of these, some 850 are in respect of irradiating apparatus only and are issued principally to dentists and veterinary surgeons. The remaining licences involve sealed radiation sources and/or unsealed radioactive substances used in medicine, industry or education. A schedule attached to each licence fully lists the sealed sources to which the licence applies, and also the quantities of radioactive substances which may be acquired or held under the licence. It is an offence to dispose of, or otherwise relinquish possession of, any licensable material other than in accordance with terms and conditions of the licence. Disused sources are returned to the original supplier or, where this is not possible, stored under licence by the licensee who used them. Enforcement of the licensing provisions relies primarily on the programme of inspection of licensees, carried out by the Institute's inspectors. The Institute's Regulatory Service has a complement of four inspectors, one of whom is the Manager of the Service. The Manager reports to one of the Institute's Principal

  2. Assessment of Economic Loss Caused by Agricultural Non-point Source Nutrient Loss

    OpenAIRE

    Fan, Liang-qian; Chen, Feng-hui

    2012-01-01

    Taking Zhejiang Province as an example, we use the JOHNES export coefficient model to estimate the total nitrogen (TN) and total phosphorus (TP) load of agricultural planting, livestock and poultry breeding and rural living non-point source in 2009. Based on the protection cost method in environmental economics, we quantitatively assess the economic loss caused by these three types of non-point source nutrient loss. The results show that in TN non-point source load, the load of land for plant...

  3. A general description of the Swedish radiation protection regulations of radioactive sources

    International Nuclear Information System (INIS)

    Staalnacke, C.-G.

    2001-01-01

    The regulation of ionizing radiation in Sweden is based on both the Radiation Protection Act and Ordinance from 1998. The Swedish Radiation Protection Institute (SSI) acts as the regulatory authority for radiation safety and issues detailed regulations in specific areas. The report summarizes how the SSI controls radiation sources, including orphan sources for which a process for analyzing their occurrence has started in Sweden. A number of proposed procedures for the control and follow-up of sealed radioactive sources is provided. (author)

  4. Apparatus and method for locating and quantifying or directing a source of ionizing radiation

    International Nuclear Information System (INIS)

    Rogers, W.L.; Wainstock, M.A.

    1976-01-01

    An apparatus and method for locating or directing a source of ionizing radiation such as X-rays, gamma rays, alpha particles, beta particles, etc. are described. The preferred embodiment detects and locates abnormalities of the body such as ocular melanomas by detecting the emission of radiation from a melanoma which has absorbed a radioactive medium. The apparatus includes an ultrasound probe which emits ultrasonic waves along a first axis and detects a returned portion of the waves. The ultrasound probe is associated with a display which displays the returned portion of the waves in the time domain so that suspected abnormalities can be located. The ultrasound probe is used to guide a directional probe for detecting and quantifying ionizing radiation which is equipped with a focusing collimator having a focal point along a second axis. The two probes are supported so that the first and second axes converge at the focal point of the collimator. A range marker is associated with the ultrasonic detector which indicates the point of convergence of the axes on the ultrasonic display permitting guidance of the radiation detecting probe to the suspected abnormality

  5. Inference of Dim Gamma-Ray Point Sources Using Probabilistic Catalogues

    Science.gov (United States)

    Daylan, Tansu; Portillo, Stephen K. N.; Finkbeiner, Douglas P.

    2016-07-01

    Poisson regression of the Fermi-LAT data in the inner Milky Way reveals an extended gamma-ray excess. The anomalous emission falls steeply away from the galactic center and has an energy spectrum that peaks at 1-2 GeV. An important question is whether the signal is coming from a collection of unresolved point sources, possibly recycled pulsars, or constitutes a truly diffuse emission component. Previous analyses have relied on non-Poissonian template fits or wavelet decomposition of the Fermi-LAT data, which find evidence for a population of dim point sources just below the 3FGL flux limit. In order to draw conclusions about a potentially dim population, we propose to sample from the catalog space of point sources, where the model dimensionality, i.e., the number of sources, is unknown. Although being a computationally expensive sampling problem, this approach allows us to infer the number, flux and radial distribution of the point sources consistent with the observed count data. Probabilistic cataloging is specifically useful in the crowded field limit, such as in the galactic disk, where the typical separation between point sources is comparable to the PSF. Using this approach, we recover the results of the deterministic Fermi-LAT 3FGL catalog, as well as sub-detection threshold information and fold the point source parameter degeneracies into the model-choice problem of whether an emission is coming from unresolved MSPs or dark matter annihilation.

  6. Risk-based prioritisation of point sources through assessment of the impact on a water supply

    DEFF Research Database (Denmark)

    Overheu, Niels D.; Tuxen, Nina; Troldborg, Mads

    2011-01-01

    vulnerability mapping, site-specific mass flux estimates on a local scale from all the sources, and 3-D catchment-scale fate and transport modelling. It handles sources at various knowledge levels and accounts for uncertainties. The tool estimates the impacts on the water supply in the catchment and provides......A large number of point sources threaten groundwater resources. A tool is presented which enables a uniform and transparent risk assessment and prioritisation of these point sources at the catchment scale with respect to the needs of further investigation or remediation. The tool integrates aquifer...

  7. Potential GTCC LLW sealed radiation source recycle initiatives

    International Nuclear Information System (INIS)

    Fischer, D.

    1992-04-01

    This report suggests 11 actions that have the potential to facilitate the recycling (reuse or radionuclide) of surplus commercial sealed radiation sources that would otherwise be disposed of as greater-than-Class C low-level radioactive waste. The suggestions serve as a basis for further investigation and discussion between the Department of Energy, Nuclear Regulatory Commission, Agreement States, and the commercial sector. Information is also given that describes sealed sources, how they are used, and problems associated with recycling, including legal concerns. To illustrate the nationwide recycling potential, Appendix A gives the estimated quantity and application information for sealed sources that would qualify for disposal in commercial facilities if not recycle. The report recommends that the Department of Energy initiate the organization of a forum to explore the suggested actions and other recycling possibilities

  8. Base substitutions, frameshifts, and small deletions constitute ionizing radiation-induced point mutations in mammalian cells

    International Nuclear Information System (INIS)

    Grosovsky, A.J.; de Boer, J.G.; de Jong, P.J.; Drobetsky, E.A.; Glickman, B.W.

    1988-01-01

    The relative role of point mutations and large genomic rearrangements in ionizing radiation-induced mutagenesis has been an issue of long-standing interest. Recent studies using Southern blotting analysis permit the partitioning of ionizing radiation-induced mutagenesis in mammalian cells into detectable deletions and major genomic rearrangements and into point mutations. The molecular nature of these point mutations has been left unresolved; they may include base substitutions as well as small deletions, insertions, and frame-shifts below the level of resolution of Southern blotting analysis. In this investigation, we have characterized a collection of ionizing radiation-induced point mutations at the endogenous adenine phosphoribosyltransferase (aprt) locus of Chinese hamster ovary cells at the DNA sequence level. Base substitutions represented approximately equal to 2/3 of the point mutations analyzed. Although the collection of mutants is relatively small, every possible type of base substitution event has been recovered. These mutations are well distributed throughout the coding sequence with only one multiple occurrence. Small deletions represented the remainder of characterized mutants; no insertions have been observed. Sequence-directed mechanisms mediated by direct repeats could account for some of the observed deletions, while others appear to be directly attributable to radiation-induced strand breakage

  9. On the evaluation of rectangular plane-extended sources and their associated radiation fields

    International Nuclear Information System (INIS)

    Oner, Feda

    2007-01-01

    The objective of this paper is to provide an efficient and reliable analytical procedure for the evaluation of rectangular plane-extended sources and their associated radiation fields. Integrals with integer and non-integer values appear in the evaluation of the radiation field distribution. The latter results from a homogeneous rectangular plane target bombarded by hollow-cylindrical ion beams, the elementary areas anisotropically emitting in non-dispersive media, and fast neutrons produced in non-dispersive media by sealed-off neutron generating tubes (NGT) in an axi-symmetric situation [Hubbell, J.H., Bach, R.L., Lamkin, J.C., 1960. Radiation from a rectangular source. J. Res. NBS 64C (2), 121-137; Hubbell, J.H., 1963a. A power series buildup factor formulation. Application to rectangular and offaxis disk source problems. J. Res. NBS 67C, 291-306, Hubbell, J.H., 1963b. Dose fields from plane sources using point-source data. Nucleonics 21 (8), 144-148; Timus et al., 2005a. Plane rectengular tritium target response to excitation by uniform distributed normal accelerated deuteron beam. Appl. Radiat. Isot. 63, 823-839; Timus et al., 2005b. Analytical characterization of radiation fields generated by certain witch-type distributed axi-symmetrical ion beams. Arab J. Nucl. Sci. Appl. 38(I) 253-264]. In these references, the resulting expressions are represented as infinite linear combinations of basic J q (a, b, z) integrals. With the help of relation for J q (a, b, z), we can evaluate the high terms of energy expressions, which have been proposed in the above-mentioned references. The extensive test calculations show that the proposed algorithm in this work is the most efficient one in practical computations

  10. Measures to reduce occupational radiation exposure in PET facilities from nurses' point of view

    International Nuclear Information System (INIS)

    Miyazawa, Keiko; Takahashi, Juri; Mochiduki, Yoshikazu

    2006-01-01

    In parallel with the increase in the number of institutions having PET facilities, the number of nurse working in these facilities has also increased, and the issue of occupational radiation exposure has assumed ever greater importance. In our clinic, since nurses have started to administer FDG intravenous injections, their annual radiation exposure has amounted to 4.8 - 7.1 mSv. To reduce their annual radiation exposure to less than 5 mSv, we identified sources of increased exposure and considered countermeasures based on this information. By implementing countermeasures such as improvements in daily working conditions and ways to avoid various troubles, it was possible to reduce the annual radiation exposure of all nurses to less than 5 mSv. Our experience demonstrates that to provide a working environment with a minimum of occupational radiation exposure, educational training and enhancement of knowledge and technical skills are vital. (author)

  11. An inverse source location algorithm for radiation portal monitor applications

    International Nuclear Information System (INIS)

    Miller, Karen A.; Charlton, William S.

    2010-01-01

    Radiation portal monitors are being deployed at border crossings throughout the world to prevent the smuggling of nuclear and radiological materials; however, a tension exists between security and the free-flow of commerce. Delays at ports-of-entry have major economic implications, so it is imperative to minimize portal monitor screening time. We have developed an algorithm to locate a radioactive source using a distributed array of detectors, specifically for use at border crossings. To locate the source, we formulated an optimization problem where the objective function describes the least-squares difference between the actual and predicted detector measurements. The predicted measurements are calculated by solving the 3-D deterministic neutron transport equation given an estimated source position. The source position is updated using the steepest descent method, where the gradient of the objective function with respect to the source position is calculated using adjoint transport calculations. If the objective function is smaller than the convergence criterion, then the source position has been identified. This paper presents the derivation of the underlying equations in the algorithm as well as several computational test cases used to characterize its accuracy.

  12. Safety issues in the handling of radiation sources in category IV gamma radiation facilities

    International Nuclear Information System (INIS)

    Kohli, A.K.

    2002-01-01

    There is potential for incidents/accidents related to handling of radiation sources. This is increasing due to the fact that more number of plants that too with much larger levels of activity are now coming up. Such facilities produce very high levels of exposure rates during irradiation. A person accidentally present in the irradiation cell can receive a lethal dose within a very short time. Apart from safety requirements during operation and maintenance of these facilities, safety during loading and unloading of sources is important. Category IV type irradiators are the most common. Doubly encapsulated Co-60 slugs are employed to form the source pencils. These irradiators employ a water pool for safely storing the source pencils when irradiation of the products is not going on or when human access is needed into the irradiation cell for some maintenance or source loading/unloading operations. Safety during loading/unloading operations of source pencils is important. In design itself care needs to be taken such that all such operations are convenient and any incident will not lead to a situation where it becomes difficult to come out. Different situations, which can arise during handling of radiation sources and suggested designs to obviate such tight situations, are discussed. (Author)

  13. Regulation of Heterogenous Non-Point Sources of Pollution Under Imperfect Information, The

    OpenAIRE

    Richard Cabe; Joseph A. Herriges

    1990-01-01

    This paper discusses the rose of information structure (i.e., information cost, reliability, and distribution among agents) in the design of a regulatory mechanism for controlling non-point source pollution. An ambient concentration tax mechanism is examined for non-point source pollution with spatial transport among multiple zones. Imposition of the tax requires costly measurement of ambient concentrations in selected zones, and the selection of zones for measurement must be undertaken witho...

  14. Complex source point theory of paraxial and nonparaxial cosine-Gauss and Bessel-Gauss beams.

    Science.gov (United States)

    Sheppard, Colin J R

    2013-02-15

    It shown how cosine-Gauss and Bessel-Gauss beams can be generated using the complex source point theory. Paraxial beams are treated first. An analytic expression is derived for the nonparaxial cosine-Gaussian beam, based on the complex source point approach, and numerical results are presented to illustrate its behavior. A way to generate nonparaxial Bessel-Gauss beams is also indicated.

  15. National system of notification, authorization and inspection for the control of radiation sources in Ghana

    International Nuclear Information System (INIS)

    Schandorf, C.; Darko, E.O.; Yeboah, J.; Asiamah, S.D.

    2001-01-01

    The Radiation Protection Board (RPB) was established in 1993 in Ghana as the regulatory authority for radiation protection and safety of radiation sources; its functions are prescribed in the 1993 national radiation protection regulation. The report describes how the country's radiation protection and safety infrastructure have been established, including the RPB's organizational structure, with reference in particular to the main activities carried out by both the Regulatory Control Department and the Radiation and Waste Safety Department. It also briefly mentions the existing RPB human resources; the national system of notification, authorization and inspection of radiation sources; the inventory of radiation sources; and the management of disused radiation sources. Finally, the report identifies the two main problem areas regarding the regulatory control of radiation sources in the country. (author)

  16. Risk perception in the process of working with radiation sources

    International Nuclear Information System (INIS)

    Carneiro, J.C.G.; Levy, D.; Sanches, M.P.; Rodrigues, D.L.; Sordi, G.M.A.A.

    2017-01-01

    This study discusses occupational risk under three distinct aspects, which are often interconnected or interdependent in the work environment. These are: environmental risks, human failures and equipment failures. The article addresses the potential exposure in the workplace, caused by the agent's physical radiation risk, resulting from handling with sources of ionizing radiation. Based on the history of accidents occurring in normal operations, the study summarizes the main accidents in various facilities and possible causes involving the three aspects of risk. In its final considerations, it presents the lessons learned and the measures to be taken with the intention of contributing to the prevention and mitigation of risks in the work environment. The analysis of accident cases and their causes provide valuable information to prevent the risk of similar accidents and contribute to the improvement of operational projects and procedures

  17. Laser sources in dentistry and radiation safety regulations

    Science.gov (United States)

    De Luca, D.; Gaeta, G. M.; Lepore, M.

    2007-02-01

    Nowadays laser sources are largely adopted in dentistry due to their unique properties making them good candidates to substitute traditional scalpel and conventional diamond bur in the surgery of the soft and hard oral tissue, respectively. The large use of laser sources outside the research laboratories without the need of highly specialized personnel can ask for a widespread knowledge of safety issues related to this kind of equipment. The main hazard of accidental exposures regards eyes injury but increasing the power of the laser beam also skin can be involved. Safety legislations in Europe and U.S.A. take into account non ionizing radiations and laser radiation for the hazards for the health deriving from physical agents. Laser safety standards introduce 3 useful parameters for hazard characterization: "Accessible Emission Limit" (AEL), "Maximum Permissible Exposure" (MPE) and "Nominal Ocular Hazard Distance" (NOHD). We measured the MPE and NOHD for Er:YAG and other laser sources currently adopted in dentistry and we compared our results with data elaborated from standards in order to single out safe and comfortable working conditions. In fact an experimental assessment of the hazard parameters and the comparison with those of reference from safety standards turns out to be useful in order to estimate the residual hazard that can be still present after applying all the engineering protection and administrative rules.

  18. Characteristics of a multi-keV monochromatic point x-ray source ...

    Indian Academy of Sciences (India)

    point x-ray source based on vacuum diode with laser-produced plasma as cathode are presented. Electrons from a laser-produced aluminium plasma were accelerated towards a conical point tip titanium anode to generate .... of an arc of radius 13 cm with the anode tip at the centre. The first cassette covered an angular ...

  19. Mapping correlation of a simulated dark matter source and a point source in the gamma-ray sky - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Alexander [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-23

    In my research, I analyzed how two gamma-ray source models interact with one another when optimizing to fit data. This is important because it becomes hard to distinguish between the two point sources when they are close together or looking at low energy photons. The reason for the first is obvious, the reason why they become harder to distinguish at lower photon energies is the resolving power of the Fermi Gamma-Ray Space Telescope gets worse at lower energies. When the two point sources are highly correlated (hard to distinguish between), we need to change our method of statistical analysis. What I did was show that highly correlated sources have larger uncertainties associated with them, caused by an optimizer not knowing which point source’s parameters to optimize. I also mapped out where their is high correlation for 2 different theoretical mass dark matter point sources so that people analyzing them in the future knew where they had to use more sophisticated statistical analysis.

  20. QUANTUM ELECTRONIC DEVICES: Superconducting Nb3Sn point contact in the submillimeter range of electromagnetic radiation

    Science.gov (United States)

    Belenov, É. M.; Danileĭko, M. V.; Derkach, V. E.; Romanenko, V. I.; Uskov, A. V.

    1988-05-01

    An investigation was made of the influence of submillimeter radiation emitted by an HCN laser operating at a frequency νl = 891 GHz on a superconducting point contact made of Nb3Sn. Three steps of the electric current were recorded. The experimental results indicated that such a contact could be used for frequency multiplication up to 3 THz.

  1. Point-like radioactive source with multiple absorber capsules for evaluating PET scanners.

    Science.gov (United States)

    Hasegawa, Tomoyuki; Yoshida, Eiji; Sato, Yasushi; Oda, Keiichi; Wada, Yasuhiro; Yamada, Takahiro; Yamaya, Taiga; Murayama, Hideo; Saito, Kyoko

    2010-06-01

    Radioactive sources for evaluating sensitivity and uncertainty in the radioactivity measurements performed using PET scanners must be equipped with absorber materials that ensure the annihilation of positrons. Attenuation and scattering owing to the absorber materials produce uncertainty in the performance evaluation. The aim of this study is to propose a point-like radioactive source with multiple absorber capsules, for which evaluation can be independent of scatter and attenuation owing to the source absorbers. The point-like source consists of a small spherical radioactive part and a set of successively sized cylindrical aluminum absorber capsules. Data were collected for different total absorber thicknesses. By an extrapolation technique, the effects of the source absorbers were eliminated. Sensitivity and uncertainty in the radioactivity measurements of PET scanners were evaluated with this technique. Sensitivity and uncertainty of radioactivity measurement to the point-like radioactive source were evaluated successfully with this method. The proposed point-like radioactive source is useful for evaluating performance characteristics of PET scanners in a way that is independent of the effects of the source absorbers.

  2. Sensitivity of the Baikal neutrino telescope NT-200 to point sources of very high energy neutrinos

    International Nuclear Information System (INIS)

    Krabi, J.; Spiering, C.; Bugaev, E.V.; Klimushin, S.I.

    1991-12-01

    The sensitivity of the deep underwater muon and neutrino detector 'NT-200' in lake Baikal to point sources of extraterrestrial neutrinos is calculated. Results are given for different assumptions on the neutrino source spectrum and the reconstruction capabilities of the detector. (orig.)

  3. Model Predictive Control of Z-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    2011-01-01

    This paper presents Model Predictive Control (MPC) of Z-source Neutral Point Clamped (NPC) inverter. For illustration, current control of Z-source NPC grid-connected inverter is analyzed and simulated. With MPC’s advantage of easily including system constraints, load current, impedance network...

  4. Research Activities Using Indus-1 Synchrotron Radiation Source

    International Nuclear Information System (INIS)

    Lodha, G. S.; Deb, S. K.

    2010-01-01

    Indus-1 is an efficient SR source in the soft x-ray / vacuum ultra violet region of the electromagnetic spectrum. For Indus-1, the higher order energy contamination in soft x-ray region, heat load and radiation safety problems are also significantly low. At present, soft x-ray-VUV reflectivity, angle integrated and angle resolved photo electron spectroscopy (ARPES), photo physics and high resolution vacuum ultra violet spectroscopy, beamlines are operational. The paper presents some of the recent studies carried out using In-dus-1.

  5. Search begins for missing radiation sources in Republic of Georgia

    International Nuclear Information System (INIS)

    2002-01-01

    An international team assembled by the IAEA will begin a search today for two abandoned Strontium 90 generators in a ca. 550 sq. km area of Western Georgia. About 80 people will take part in the two-week search beginning on Monday, 10 June. Radiation experts for the IAEA, India, France, Turkey and the U.S. are also part of the team, which will set out on horseback, foot and by car. The second phase - an aerial and road survey covering different territory - is scheduled to begin in early September. The objective is to locate and recover other known or suspected orphaned radioactive sources in the country

  6. Measurement of parameters in Indus-2 synchrotron radiation source.

    Science.gov (United States)

    Ghodke, A D; Husain, Riyasat; Kumar, Pradeep; Yadav, Surendra; Puntambekar, T A

    2012-10-01

    The paper presents the measurement of optics parameters in Indus-2 synchrotron radiation source, which include betatron tune, beta function, dispersion function, natural chromaticity, corrected chromaticity, central RF frequency, momentum compaction factor, and linear betatron coupling. Two methods were used for beta function measurement; a conventional quadrupole scan method and a method using the fitting of the orbit response matrix. A robust Levenberg-Marquardt algorithm was used for nonlinear least square fitting of the orbit response matrix. In this paper, detailed methods for the parameter measurements are described. The measured results are discussed and compared with the theoretical values obtained using accelerator simulation code Accelerator Toolbox in MATLAB.

  7. Freeze drying method for preparing radiation source material

    International Nuclear Information System (INIS)

    Mosley, W.C. Jr.; Smith, P.K.

    1975-01-01

    A solution containing radioisotope and palladium values is atomized into an air flow entering a cryogenically cooled chamber where the solution is deposited on the chamber walls as a thin layer of frozen material. The solvent portion of the frozen material is sublimated into a cold trap by elevating the temperature within the chamber while withdrawing solvent vapors. The residual crystals are heated to provide a uniformly mixed powder of palladium metal and a refractory radioisotope compound. The powder is thereafter consolidated into a pellet and further shaped into rod, wire or sheet form for easy apportionment into individual radiation sources. (U.S.)

  8. Miniature x-ray point source for alignment and calibration of x-ray optics

    International Nuclear Information System (INIS)

    Price, R.H.; Boyle, M.J.; Glaros, S.S.

    1977-01-01

    A miniature x-ray point source of high brightness similar to that of Rovinsky, et al. is described. One version of the x-ray source is used to align the x-ray optics on the Argus and Shiva laser systems. A second version is used to determine the spatial and spectral transmission functions of the x-ray optics. The spatial and spectral characteristics of the x-ray emission from the x-ray point source are described. The physical constraints including size, intensity and thermal limitations, and useful lifetime are discussed. The alignment and calibration techniques for various x-ray optics and detector combinations are described

  9. Production of radioisotopic gamma radiation sources in JAERI

    International Nuclear Information System (INIS)

    Katoh, Hisashi; Kogure, Hiroto; Suzuki, Kyohei

    1980-04-01

    The present state of production of gamma radiation sources in Japan Atomic Energy Research Institute (JAERI) is described. Sources of 192 Ir, 60 Co and 170 Tm for industrial and 198 Au and 192 Ir for medical applications are produced and delivered routinely by JAERI. Prefabricated assembly targets are irradiated in JRR-2, JRR-3, JRR-4 or JMTR. The irradiated targets are disassembled in a heavy density concrete cave or a lead-shielded cell, depending on the level of radioactivity. The yield of radioactivity in each target is measured with the aid of an ionization chamber. Where necessary, irradiated targets are encapsulated hermetically in capsules of aluminium, stainless steel or other material. The yield of radioactivity is estimated in relation with the burn-up of target nuclide and product nuclide. (author)

  10. Source tilting within the difference formulation for radiation transport

    Energy Technology Data Exchange (ETDEWEB)

    Luu, T; Brooks, E; Szoke, A

    2006-09-27

    We apply a heuristic technique known as 'source tilting' to a Monte Carlo solution for radiation transport, in the difference formulation, that otherwise employs a piecewise-constant treatment of the material temperature. Source tilting improves the accuracy of the piecewise-constant treatment, reducing the excessive energy flow that occurs in the thick limit. An analysis of the cause of excessive energy flow suggests an interpolation scheme that removes this defect, obtaining the correct diffusion limit flux between zones. The results obtained with our interpolation scheme agree almost identically to those of a self-consistent piecewise-linear treatment of the difference formulation while avoiding its additional costs. The resulting method is capable of providing robust and accurate calculations for problems involving optically thick zones. We comment on the monotonicity issues that arise when employing this transport method.

  11. The adaptive collision source method for discrete ordinates radiation transport

    International Nuclear Information System (INIS)

    Walters, William J.; Haghighat, Alireza

    2017-01-01

    Highlights: • A new adaptive quadrature method to solve the discrete ordinates transport equation. • The adaptive collision source (ACS) method splits the flux into n’th collided components. • Uncollided flux requires high quadrature; this is lowered with number of collisions. • ACS automatically applies appropriate quadrature order each collided component. • The adaptive quadrature is 1.5–4 times more efficient than uniform quadrature. - Abstract: A novel collision source method has been developed to solve the Linear Boltzmann Equation (LBE) more efficiently by adaptation of the angular quadrature order. The angular adaptation method is unique in that the flux from each scattering source iteration is obtained, with potentially a different quadrature order used for each. Traditionally, the flux from every iteration is combined, with the same quadrature applied to the combined flux. Since the scattering process tends to distribute the radiation more evenly over angles (i.e., make it more isotropic), the quadrature requirements generally decrease with each iteration. This method allows for an optimal use of processing power, by using a high order quadrature for the first iterations that need it, before shifting to lower order quadratures for the remaining iterations. This is essentially an extension of the first collision source method, and is referred to as the adaptive collision source (ACS) method. The ACS methodology has been implemented in the 3-D, parallel, multigroup discrete ordinates code TITAN. This code was tested on a several simple and complex fixed-source problems. The ACS implementation in TITAN has shown a reduction in computation time by a factor of 1.5–4 on the fixed-source test problems, for the same desired level of accuracy, as compared to the standard TITAN code.

  12. Building competence in radiation protection and the safe use of radiation sources. Safety guide (Spanish ed.)

    International Nuclear Information System (INIS)

    2010-01-01

    This Safety Guide makes recommendations concerning the building of competence in protection and safety within a national radiation protection infrastructure and provides guidance for setting up the structure for a national strategy. It relates to the training and assessment of qualification of new personnel and the retraining of existing personnel in order to develop and maintain appropriate levels of competence. It provides the necessary guidance to meet the requirements laid down in Safety Series No. 115, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. Contents: 1. Introduction; 2. Responsibilities for building competence in protection and safety; 3. Education, training and work experience; 4. A national strategy for building competence in protection and safety.

  13. [Spatial heterogeneity and classified control of agricultural non-point source pollution in Huaihe River Basin].

    Science.gov (United States)

    Zhou, Liang; Xu, Jian-Gang; Sun, Dong-Qi; Ni, Tian-Hua

    2013-02-01

    Agricultural non-point source pollution is of importance in river deterioration. Thus identifying and concentrated controlling the key source-areas are the most effective approaches for non-point source pollution control. This study adopts inventory method to analysis four kinds of pollution sources and their emissions intensity of the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in 173 counties (cities, districts) in Huaihe River Basin. The four pollution sources include livestock breeding, rural life, farmland cultivation, aquacultures. The paper mainly addresses identification of non-point polluted sensitivity areas, key pollution sources and its spatial distribution characteristics through cluster, sensitivity evaluation and spatial analysis. A geographic information system (GIS) and SPSS were used to carry out this study. The results show that: the COD, TN and TP emissions of agricultural non-point sources were 206.74 x 10(4) t, 66.49 x 10(4) t, 8.74 x 10(4) t separately in Huaihe River Basin in 2009; the emission intensity were 7.69, 2.47, 0.32 t.hm-2; the proportions of COD, TN, TP emissions were 73%, 24%, 3%. The paper achieves that: the major pollution source of COD, TN and TP was livestock breeding and rural life; the sensitivity areas and priority pollution control areas among the river basin of non-point source pollution are some sub-basins of the upper branches in Huaihe River, such as Shahe River, Yinghe River, Beiru River, Jialu River and Qingyi River; livestock breeding is the key pollution source in the priority pollution control areas. Finally, the paper concludes that pollution type of rural life has the highest pollution contribution rate, while comprehensive pollution is one type which is hard to control.

  14. Guaranteed Unresolved Point Source Emission and the Gamma-ray Background

    International Nuclear Information System (INIS)

    Pavlidou, Vasiliki; Siegal-Gaskins, Jennifer M.; Brown, Carolyn; Fields, Brian D.; Olinto, Angela V.

    2007-01-01

    The large majority of EGRET point sources remain without an identified low-energy counterpart, and a large fraction of these sources are most likely extragalactic. Whatever the nature of the extragalactic EGRET unidentified sources, faint unresolved objects of the same class must have a contribution to the diffuse extragalactic gamma-ray background (EGRB). Understanding this component of the EGRB, along with other guaranteed contributions from known sources (blazars and normal galaxies), is essential if we are to use this emission to constrain exotic high-energy physics. Here, we follow an empirical approach to estimate whether the contribution of unresolved unidentified sources to the EGRB is likely to be important. Additionally, we discuss how upcoming GLAST observations of EGRET unidentified sources, their fainter counterparts, and the Galactic and extragalactic diffuse backgrounds, will shed light on the nature of the EGRET unidentified sources even without any positional association of such sources with low-energy counterparts

  15. Extending the search for neutrino point sources with IceCube above the horizon.

    Science.gov (United States)

    Abbasi, R; Abdou, Y; Abu-Zayyad, T; Adams, J; Aguilar, J A; Ahlers, M; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Bay, R; Bazo Alba, J L; Beattie, K; Beatty, J J; Bechet, S; Becker, J K; Becker, K-H; Benabderrahmane, M L; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bissok, M; Blaufuss, E; Boersma, D J; Bohm, C; Botner, O; Bradley, L; Braun, J; Breder, D; Carson, M; Castermans, T; Chirkin, D; Christy, B; Clem, J; Cohen, S; Cowen, D F; D'Agostino, M V; Danninger, M; Day, C T; De Clercq, C; Demirörs, L; Depaepe, O; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Díaz-Vélez, J C; Dreyer, J; Dumm, J P; Duvoort, M R; Edwards, W R; Ehrlich, R; Eisch, J; Ellsworth, R W; Engdegård, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Feusels, T; Filimonov, K; Finley, C; Foerster, M M; Fox, B D; Franckowiak, A; Franke, R; Gaisser, T K; Gallagher, J; Ganugapati, R; Gerhardt, L; Gladstone, L; Goldschmidt, A; Goodman, J A; Gozzini, R; Grant, D; Griesel, T; Gross, A; Grullon, S; Gunasingha, R M; Gurtner, M; Ha, C; Hallgren, A; Halzen, F; Han, K; Hanson, K; Hasegawa, Y; Helbing, K; Herquet, P; Hickford, S; Hill, G C; Hoffman, K D; Homeier, A; Hoshina, K; Hubert, D; Huelsnitz, W; Hülss, J-P; Hulth, P O; Hultqvist, K; Hussain, S; Imlay, R L; Inaba, M; Ishihara, A; Jacobsen, J; Japaridze, G S; Johansson, H; Joseph, J M; Kampert, K-H; Kappes, A; Karg, T; Karle, A; Kelley, J L; Kemming, N; Kenny, P; Kiryluk, J; Kislat, F; Klein, S R; Knops, S; Kohnen, G; Kolanoski, H; Köpke, L; Koskinen, D J; Kowalski, M; Kowarik, T; Krasberg, M; Krings, T; Kroll, G; Kuehn, K; Kuwabara, T; Labare, M; Lafebre, S; Laihem, K; Landsman, H; Lauer, R; Lehmann, R; Lennarz, D; Lundberg, J; Lünemann, J; Madsen, J; Majumdar, P; Maruyama, R; Mase, K; Matis, H S; McParland, C P; Meagher, K; Merck, M; Mészáros, P; Meures, T; Middell, E; Milke, N; Miyamoto, H; Montaruli, T; Morse, R; Movit, S M; Nahnhauer, R; Nam, J W; Niessen, P; Nygren, D R; Odrowski, S; Olivas, A; Olivo, M; Ono, M; Panknin, S; Patton, S; Paul, L; Pérez de los Heros, C; Petrovic, J; Piegsa, A; Pieloth, D; Pohl, A C; Porrata, R; Potthoff, N; Price, P B; Prikockis, M; Przybylski, G T; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Rizzo, A; Rodrigues, J P; Roth, P; Rothmaier, F; Rott, C; Roucelle, C; Rutledge, D; Ruzybayev, B; Ryckbosch, D; Sander, H-G; Sarkar, S; Schatto, K; Schlenstedt, S; Schmidt, T; Schneider, D; Schukraft, A; Schulz, O; Schunck, M; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Slipak, A; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stephens, G; Stezelberger, T; Stokstad, R G; Stoufer, M C; Stoyanov, S; Strahler, E A; Straszheim, T; Sullivan, G W; Swillens, Q; Taboada, I; Tamburro, A; Tarasova, O; Tepe, A; Ter-Antonyan, S; Terranova, C; Tilav, S; Toale, P A; Tooker, J; Tosi, D; Turcan, D; van Eijndhoven, N; Vandenbroucke, J; Van Overloop, A; van Santen, J; Voigt, B; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Wiedemann, A; Wikström, G; Williams, D R; Wischnewski, R; Wissing, H; Woschnagg, K; Xu, C; Xu, X W; Yodh, G; Yoshida, S

    2009-11-27

    Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

  16. Tackling non-point source water pollution in British Columbia: An action plan

    Energy Technology Data Exchange (ETDEWEB)

    1998-01-01

    Efforts to protect British Columbia water quality by regulating point discharges from municipal and industrial sources have generally been successful, and it is recognized that the major remaining cause of water pollution in the province is from non-point sources. These sources are largely unregulated and associated with urbanization, agriculture, and other forms of land development. The first part of this report reviews the provincial commitment to clean water, the effects of non-point-source (NPS) pollution, and the management of NPS in the province. Part 2 describes the main causes of NPS in British Columbia: Land development, agriculture, stormwater runoff, on-site sewage systems, forestry and range activities, atmospheric deposition, and boating/marine activities. Finally, it presents key components of the province's NPS action plan: Education and training, prevention at site, land use planning and co-ordination, assessment and reporting, economic incentives, legislation and regulation, and implementation.

  17. Extending the search for neutrino point sources with IceCube above the horizon

    Energy Technology Data Exchange (ETDEWEB)

    IceCube Collaboration; Abbasi, R.

    2009-11-20

    Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This approach improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

  18. Regulatory Control of Radiation Sources. Safety Guide (Arabic Edition)

    International Nuclear Information System (INIS)

    2012-01-01

    This Safety Guide is intended to assist States in implementing the requirements established in Safety Standards Series No. GS-R-1, Legal and Governmental Infrastructure for Nuclear, Radiation, Radioactive Waste and Transport Safety, for a national regulatory infrastructure to regulate any practice involving radiation sources in medicine, industry, research, agriculture and education. The Safety Guide provides advice on the legislative basis for establishing regulatory bodies, including the effective independence of the regulatory body. It also provides guidance on implementing the functions and activities of regulatory bodies: the development of regulations and guides on radiation safety; implementation of a system for notification and authorization; carrying out regulatory inspections; taking necessary enforcement actions; and investigating accidents and circumstances potentially giving rise to accidents. The various aspects relating to the regulatory control of consumer products are explained, including justification, optimization of exposure, safety assessment and authorization. Guidance is also provided on the organization and staffing of regulatory bodies. Contents: 1. Introduction; 2. Legal framework for a regulatory infrastructure; 3. Principal functions and activities of the regulatory body; 4. Regulatory control of the supply of consumer products; 5. Functions of the regulatory body shared with other governmental agencies; 6. Organization and staffing of the regulatory body; 7. Documentation of the functions and activities of the regulatory body; 8. Support services; 9. Quality management for the regulatory system.

  19. Probable sources of errors in radiation therapy (abstract)

    International Nuclear Information System (INIS)

    Khan, U.H.

    1998-01-01

    It is fact that some errors are always in dose-volume prescription, management of radiation beam, derivation of exposure, planning the treatment and finally the treatment of the patient ( a three dimensional subject). This paper highlights all the sources of error and relevant methods to decrease or eliminate them, thus improving the over-all therapeutic efficiency and accuracy. It is a comprehensive teamwork of the radiotherapist, medical radiation physicist, medical technologist and the patient. All the links, in the whole chain of radiotherapy, are equally important and duly considered in the paper. The decision for Palliative or Radical treatment is based on the nature and extent disease, site, stage, grade, length of the history of condition and biopsy reports etc. This may entail certain uncertainties in Volume of tumor, quality and quantity of radiation and dose fractionation etc, which may be under or over-estimated. An effort has been made to guide the radiotherapist in avoiding the pitfalls in the arena of radiotherapy. (author)

  20. The Advanced Light Source: A third-generation Synchrotron Radiation Source

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Arthur L.

    2002-08-14

    The Advanced Light Source (ALS) at the E.O. Lawrence Berkeley National Laboratory (Berkeley Lab) of the University of California is a ''third-generation'' synchrotron radiation source optimized for highest brightness at ultraviolet and soft x-ray photon energies. It also provides world-class performance at hard x-ray photon energies. Berkeley Lab operates the ALS for the United States Department of Energy as a national user facility that is available 24 hours/day around the year for research by scientists from industrial, academic, and government laboratories primarily from the United States but also from abroad.

  1. Methods of computer experiment in gamma-radiation technologies using new radiation sources

    CERN Document Server

    Bratchenko, M I; Rozhkov, V V

    2001-01-01

    Presented id the methodology of computer modeling application for physical substantiation of new irradiation technologies and irradiators design work flow. Modeling tasks for irradiation technologies are structured along with computerized methods of their solution and appropriate types of software. Comparative analysis of available packages for Monte-Carlo modeling of electromagnetic processes in media is done concerning their application to irradiation technologies problems. The results of codes approbation and preliminary data on gamma-radiation absorbed dose distributions for nuclides of conventional sources and prospective Europium-based gamma-sources are presented.

  2. Insurance of Radioisotopes and Ionizing Radiation Sources in France

    International Nuclear Information System (INIS)

    Stanislas, A.

    2008-01-01

    Since the early sixties, Assuratome has amassed quite a long experience in the insurance of radioisotopes and more generally of ionising radiation sources when they are used transported or stored outside a nuclear installation. Aware of the specific dangers of such devices, and having no experience in this domain French insurers were looking for a pragmatic solution which would permit to continue to provide cover for users or fabricants of small radioactive sources and in the meantime to keep a rigorous control on the claims and on the loss ratio which would be achieved over the years. Hence the decision was taken by the French Insurance market to entrust the French Nuclear Insurance Pool, Assuratome, as the recommended body for delivering specific 'nuclear policies' as an expert for this category of business. The next step was to make sure that the 'conventional policies' would not provide the same cover. Therefore, an appropriate exclusion clause was introduced in all the general conditions of the TPL Policies of the conventional market and consequently in the majority, if not all, the reinsurance treaties. Besides the obvious advantage resulting in the management of this category of business in a centralised body, a major benefit of this situation is based on the strict control by the insurer of the compulsory authorisation delivered by the authorities to the owner of the radioactive source. Unofficial sources having in principal no insurance possibilities in France their use would be virtually impossible.(author)

  3. Radiation exposure from consumer products and miscellaneous sources

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    This review of the literature indicates that there is a variety of consumer products and miscellaneous sources of radiation that result in exposure to the U.S. population. A summary of the number of people exposed to each such source, an estimate of the resulting dose equivalents to the exposed population, and an estimate of the average annual population dose equivalent are tabulated. A review of the data in this table shows that the total average annual contribution to the whole-body dose equivalent of the U.S. population from consumer products is less than 5 mrem; about 70 percent of this arises from the presence of naturally-occurring radionuclides in building materials. Some of the consumer product sources contribute exposure mainly to localized tissues or organs. Such localized estimates include: 0.5 to 1 mrem to the average annual population lung dose equivalent (generalized); 2 rem to the average annual population bronchial epithelial dose equivalent (localized); and 10 to 15 rem to the average annual population basal mucosal dose equivalent (basal mucosa of the gum). Based on these estimates, these sources may be grouped or classified as those that involve many people and the dose equivalent is relative large or those that involve many people but the dose equivalent is relatively small, or the dose equivalent is relatively large but the number of people involved is small

  4. Borehole disposal of spent radiation sources: 1. Principles

    International Nuclear Information System (INIS)

    Blerk, J.J. van; Kozak, M.W.

    2000-01-01

    Large numbers of spent radiation sources from the medical and other technical professions exist in many countries, even countries that do not possess facilities related to the nuclear fuel cycle, that have to be disposed. This is particularly the case in Africa, South America and some members of the Russian Federation. Since these sources need to be handled separately from the other types of radioactive waste, mainly because of their activity to volume ratio, countries (even those with access to operational repositories) find it difficult to manage and dispose this waste. This has led to the use of boreholes as disposal units for these spent sources by some members of the Russian Federation and in South Africa. However, the relatively shallow boreholes used by these countries are not suitable for the disposal of isotopes with long half-lifes, such as 226 Ra and 241 Am. With this in mind the Atomic Energy Corporation of South Africa initiated the development of the BOSS disposal concept - an acronym for Borehole disposal Of Spent Sources - as part of an International Atomic Energy Agency (IAEA) AFRA I-14 Technical Corporation (TC) project. In this paper, the principles of this disposal concept, which is still under development, will be discussed. (author)

  5. The IAEA Regional Training Course on Regulatory Control of Radiation Sources

    International Nuclear Information System (INIS)

    2000-01-01

    Materials of the IAEA Regional Training Course contains 8 presented lectures. Authors deals with regulatory control of radiation sources. The next materials of the IAEA were presented: Organization and implementation of a national regulatory infrastructure governing protection against ionizing radiation and the safety of radiation sources. (IAEA-TECDOC-1067); Safety assessment plants for authorization and inspection of radiation sources (IAEA-TECDOC-1113); Regulatory authority information system RAIS, Version 2.0, Instruction manual

  6. [Coronary CT angiography using a prospective protocol. Comparison of image quality and radiation dose between dual source CT and single source CT].

    Science.gov (United States)

    Duarte, R; Miranda, D; Fernández-Pérez, G; Costa, J C

    2013-01-01

    To compare the image quality and radiation dose in a group of patients undergoing coronary CT angiography using a 128-slice dual source helical CT scanner with high pitch alto and prospective acquisition with those in a group of patients with similar clinical characteristics undergoing coronary CT angiography using a 128-slice single-source CT scanner with prospective sequential acquisition. We included 80 patients with heart rates ≤65 beats/min: 40 underwent sequential 128-slice single source CT with prospective synchronization and the other 40 underwent 128-slice dual source helical CT with high pitch and prospective synchronization. Two radiologists independently assessed the quality of the images of the coronary arteries on the 80 coronary CT angiograms: image quality was classified on a four-point scale in which 1 represented excellent and 4 deficient. The effective dose of radiation was also calculated. The clinical characteristics of the patients in the two groups were similar. The image quality obtained with dual source CT was significantly better than that obtained with single source CT (P=0.006). The mean effective dose of radiation in the group undergoing dual source CT was 36% lower than in the group undergoing single source CT (1.4±0.6 mSv vs. 2.2±0.9 mSv; Psource CT with prospective acquisition and 128-slice dual source helical CT with high pitch and prospective acquisition provide good image quality and low effective doses of radiation, 128-slice dual source helical CT with prospective acquisition provides better image quality and results in a lower effective dose of radiation. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  7. Experimental study of radiation dose rate at different strategic points of the BAEC TRIGA Research Reactor.

    Science.gov (United States)

    Ajijul Hoq, M; Malek Soner, M A; Salam, M A; Haque, M M; Khanom, Salma; Fahad, S M

    2017-12-01

    The 3MW TRIGA Mark-II Research Reactor of Bangladesh Atomic Energy Commission (BAEC) has been under operation for about thirty years since its commissioning at 1986. In accordance with the demand of fundamental nuclear research works, the reactor has to operate at different power levels by utilizing a number of experimental facilities. Regarding the enquiry for safety of reactor operating personnel and radiation workers, it is necessary to know the radiation level at different strategic points of the reactor where they are often worked. In the present study, neutron, beta and gamma radiation dose rate at different strategic points of the reactor facility with reactor power level of 2.4MW was measured to estimate the rising level of radiation due to its operational activities. From the obtained results high radiation dose is observed at the measurement position of the piercing beam port which is caused by neutron leakage and accordingly, dose rate at the stated position with different reactor power levels was measured. This study also deals with the gamma dose rate measurements at a fixed position of the reactor pool top surface for different reactor power levels under both Natural Convection Cooling Mode (NCCM) and Forced Convection Cooling Mode (FCCM). Results show that, radiation dose rate is higher for NCCM in compared with FCCM and increasing with the increase of reactor power. Thus, concerning the radiological safety issues for working personnel and the general public, the radiation dose level monitoring and the experimental analysis performed within this paper is so much effective and the result of this work can be utilized for base line data and code verification of the nuclear reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The Spectral Statistical Method for Determining the Location Parameters of a Dipole Source of Electromagnetic Radiation

    Science.gov (United States)

    Panyukov, A. V.; Bogushov, A. K.

    2016-09-01

    Using the measured horizontal and vertical components of the magnetic and electric fields, respectively, we solve the problem of determining the location of a dipole source of electromagnetic radiation, which is equivalent to the lightning discharge, at the specified point of an infinitely conducting plane. The proposed method, which is based on the analysis of the measured-signal spectra, allows one to develop many estimates of the source location, choose the final estimate on the basis of the results of analysis of the entire totality of these estimates, and, therefore, reach stability in determining the source location. The spectral method makes it possible to obtain more stable solutions at a lower computation cost compared with the previously developed parametric extremum method. The spectral-method algorithm can be naturally parallelized. The results of the analytical and numerical studies of the accuracy and stability of the proposed method are presented.

  9. Flux and brightness calculations for various synchrotron radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Weber, J.M.; Hulbert, S.L.

    1991-11-01

    Synchrotron radiation (SR) storage rings are powerful scientific and technological tools. The first generation of storage rings in the US., e.g., SURF (Washington, D.C.), Tantalus (Wisconsin), SSRL (Stanford), and CHESS (Cornell), revolutionized VUV, soft X-ray, and hard X-ray science. The second (present) generation of storage rings, e.g. the NSLS VUV and XRAY rings and Aladdin (Wisconsin), have sustained the revolution by providing higher stored currents and up to a factor of ten smaller electron beam sizes than the first generation sources. This has made possible a large number of experiments that could not performed using first generation sources. In addition, the NSLS XRAY ring design optimizes the performance of wigglers (high field periodic magnetic insertion devices). The third generation storage rings, e.g. ALS (Berkeley) and APS (Argonne), are being designed to optimize the performance of undulators (low field periodic magnetic insertion devices). These extremely high brightness sources will further revolutionize x-ray science by providing diffraction-limited x-ray beams. The output of undulators and wigglers is distinct from that of bending magnets in magnitude, spectral shape, and in spatial and angular size. Using published equations, we have developed computer programs to calculate the flux, central intensity, and brightness output bending magnets and selected wigglers and undulators of the NSLS VUV and XRAY rings, the Advanced Light Source (ALS), and the Advanced Photon Source (APS). Following is a summary of the equations used, the graphs and data produced, and the computer codes written. These codes, written in the C programming language, can be used to calculate the flux, central intensity, and brightness curves for bending magnets and insertion devices on any storage ring.

  10. Flux and brightness calculations for various synchrotron radiation sources

    International Nuclear Information System (INIS)

    Weber, J.M.; Hulbert, S.L.

    1991-11-01

    Synchrotron radiation (SR) storage rings are powerful scientific and technological tools. The first generation of storage rings in the US., e.g., SURF (Washington, D.C.), Tantalus (Wisconsin), SSRL (Stanford), and CHESS (Cornell), revolutionized VUV, soft X-ray, and hard X-ray science. The second (present) generation of storage rings, e.g. the NSLS VUV and XRAY rings and Aladdin (Wisconsin), have sustained the revolution by providing higher stored currents and up to a factor of ten smaller electron beam sizes than the first generation sources. This has made possible a large number of experiments that could not performed using first generation sources. In addition, the NSLS XRAY ring design optimizes the performance of wigglers (high field periodic magnetic insertion devices). The third generation storage rings, e.g. ALS (Berkeley) and APS (Argonne), are being designed to optimize the performance of undulators (low field periodic magnetic insertion devices). These extremely high brightness sources will further revolutionize x-ray science by providing diffraction-limited x-ray beams. The output of undulators and wigglers is distinct from that of bending magnets in magnitude, spectral shape, and in spatial and angular size. Using published equations, we have developed computer programs to calculate the flux, central intensity, and brightness output bending magnets and selected wigglers and undulators of the NSLS VUV and XRAY rings, the Advanced Light Source (ALS), and the Advanced Photon Source (APS). Following is a summary of the equations used, the graphs and data produced, and the computer codes written. These codes, written in the C programming language, can be used to calculate the flux, central intensity, and brightness curves for bending magnets and insertion devices on any storage ring

  11. Global source attribution of sulfate aerosol and its radiative forcing

    Science.gov (United States)

    Yang, Y.; Wang, H.; Smith, S.; Easter, R. C.; Ma, P. L.; Qian, Y.; Li, C.; Yu, H.; Rasch, P. J.

    2017-12-01

    Sulfate is an important aerosol that poses health risks and influences climate. Due to long-range atmospheric transport, local sulfate pollution could result from intercontinental influences, making domestic efforts of improving air quality inefficient. Accurate understanding of source attribution of sulfate and its radiative forcing is important for both regional air quality improvement and global climate mitigation. In this study, for the first time, a sulfur source-tagging capability is implemented in the Community Atmosphere Model (CAM5) to quantify the global source-receptor relationships of sulfate and its direct and indirect radiative forcing (DRF and IRF). Near-surface sulfate concentrations are mostly contributed by local emissions in regions with high emissions, while over regions with relatively low SO2 emissions, the near-surface sulfate is primarily attributed to non-local sources from long-range transport. The export of SO2 and sulfate from Europe contributes 20% of sulfate concentrations over North Africa, Russia and Central Asia. Sources from the Middle East account for 20% of sulfate over North Africa, Southern Africa and Central Asia in winter and autumn, and 20% over South Asia in spring. East Asia accounts for about 50% of sulfate over Southeast Asia in winter and autumn, 15% over Russia in summer, and 10% over North America in spring. South Asia contributes to 25% of sulfate over Southeast Asia in spring. Lifetime of aerosols, together with regional export, is found to determine regional air quality. The simulated global total sulfate DRF is -0.42 W m-2, with 75% contributed by anthropogenic sulfate and 25% contributed by natural sulfate. In the Southern Hemisphere tropics, dimethyl sulfide (DMS) contributes the most to the total DRF. East Asia has the largest contribution of 20-30% over the Northern Hemisphere mid- and high-latitudes. A 20% perturbation of sulfate and its precursor emissions gives a sulfate IRF of -0.44 W m-2. DMS has the

  12. Safety assessment plans for authorization and inspection of radiation sources

    International Nuclear Information System (INIS)

    1999-09-01

    The objective of this TECDOC is to enhance the efficacy, quality and efficiency of the whole regulatory process. It provides advice on good practice administrative procedures for the regulatory process for preparation of applications, granting of authorizations, inspection, and enforcement. It also provides information on the development and use of standard safety assessment plans for authorization and inspection. The plans are intended to be used in conjunction with more detailed advice related to specific practices. In this sense, this TECDOC provides advice on a systematic approach to evaluations of protection and safety while other IAEA Safety Guides assist the user to distinguish between the acceptable and the unacceptable. This TECDOC covers administrative advice to facilitate the regulatory process governing authorization and inspection. It also covers the use of standard assessment and inspection plans and provides simplified plans for the more common, well established uses of radiation sources in medicine and industry, i.e. sources for irradiation facilities, industrial radiography, well logging, industrial gauging, unsealed sources in industry, X ray diagnosis, nuclear medicine, teletherapy and brachytherapy

  13. Phase space of positron trajectories exiting a charged particle source through a magnetic field point cusp

    International Nuclear Information System (INIS)

    Kiester, A.S.; Pacheco, J.L.; Ordonez, C.A.; Weathers, D.L.

    2014-01-01

    A configuration of magnetic fields using properties of cylindrically symmetric permanent magnets is presented as a candidate to produce a high purity charged particle source or trap. Cylindrically symmetric hollow permanent magnets produce magnetic field point cusps on the axis of symmetry. A magnetic field point cusp reflects all particles that lie outside a narrow region of phase space, a region dependent on particle kinetic energies and on the magnetic field intensity. An analysis of the phase space of positron trajectories entering and exiting a magnetic field point cusp is presented and quantified with respect to magnetic field intensity and particle kinetic energy. Preliminary experimental results support the use of point cusps for ion source applications

  14. Nonlinear radiative heat transfer to stagnation-point flow of Sisko fluid past a stretching cylinder

    Directory of Open Access Journals (Sweden)

    Masood Khan

    2016-05-01

    Full Text Available In the present paper, we endeavor to perform a numerical analysis in connection with the nonlinear radiative stagnation-point flow and heat transfer to Sisko fluid past a stretching cylinder in the presence of convective boundary conditions. The influence of thermal radiation using nonlinear Rosseland approximation is explored. The numerical solutions of transformed governing equations are calculated through forth order Runge-Kutta method using shooting technique. With the help of graphs and tables, the influence of non-dimensional parameters on velocity and temperature along with the local skin friction and Nusselt number is discussed. The results reveal that the temperature increases however, heat transfer from the surface of cylinder decreases with the increasing values of thermal radiation and temperature ratio parameters. Moreover, the authenticity of numerical solutions is validated by finding their good agreement with the HAM solutions.

  15. mtDNA point and length heteroplasmy in high- and low radiation areas of Kerala

    International Nuclear Information System (INIS)

    Forster, L.; Forster, P.; Gurney, S.M.; Spencer, M.; Huang, C.; Röhl, A.; Brinkmann, B.

    2010-01-01

    A coastal peninsula in Kerala (India) contains the world's highest level of natural radioactivity in a densely populated area, offering an opportunity to characterize radiation-associated DNA mutations. Here, we focus on mitochondrial DNA (mtDNA) mutations, which are passed exclusively from the mother to her children. To analyse point mutations, we sampled 248 pedigrees (988 individuals) in the high-radiation peninsula and in nearby low-radiation islands as a control population. Then, in an extended sample of 1,172 mtDNA sequences (containing some non-Indians for comparison), we also analysed length mutations, which in mtDNA can lead to the phenomenon of length heteroplasmy, i.e. the existence of different DNA types in the same cell. We wished to find out how fast mtDNA mutates between generations, and whether the mutation rate is increased in radioactive conditions compared to the low-irradiation sample

  16. Nonlinear radiative heat transfer to stagnation-point flow of Sisko fluid past a stretching cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Masood [Department of Mathematics, Quaid-i-Azam University, Islamabad 44000 (Pakistan); Malik, Rabia, E-mail: rabiamalik.qau@gmail.com [Department of Mathematics, Quaid-i-Azam University, Islamabad 44000 (Pakistan); Department of Mathematics and Statistics, International Islamic University Islamabad 44000 (Pakistan); Hussain, M. [Department of Sciences and Humanities, National University of Computer and Emerging Sciences, Islamabad 44000 (Pakistan)

    2016-05-15

    In the present paper, we endeavor to perform a numerical analysis in connection with the nonlinear radiative stagnation-point flow and heat transfer to Sisko fluid past a stretching cylinder in the presence of convective boundary conditions. The influence of thermal radiation using nonlinear Rosseland approximation is explored. The numerical solutions of transformed governing equations are calculated through forth order Runge-Kutta method using shooting technique. With the help of graphs and tables, the influence of non-dimensional parameters on velocity and temperature along with the local skin friction and Nusselt number is discussed. The results reveal that the temperature increases however, heat transfer from the surface of cylinder decreases with the increasing values of thermal radiation and temperature ratio parameters. Moreover, the authenticity of numerical solutions is validated by finding their good agreement with the HAM solutions.

  17. PSFGAN: a generative adversarial network system for separating quasar point sources and host galaxy light

    Science.gov (United States)

    Stark, Dominic; Launet, Barthelemy; Schawinski, Kevin; Zhang, Ce; Koss, Michael; Turp, M. Dennis; Sartori, Lia F.; Zhang, Hantian; Chen, Yiru; Weigel, Anna K.

    2018-03-01

    The study of unobscured active galactic nuclei (AGN) and quasars depends on the reliable decomposition of the light from the AGN point source and the extended host galaxy light. The problem is typically approached using parametric fitting routines using separate models for the host galaxy and the point spread function (PSF). We present a new approach using a Generative Adversarial Network (GAN) trained on galaxy images. We test the method using Sloan Digital Sky Survey (SDSS) r-band images with artificial AGN point sources added which are then removed using the GAN and with parametric methods using GALFIT. When the AGN point source PS is more than twice as bright as the host galaxy, we find that our method, PSFGAN, can recover PS and host galaxy magnitudes with smaller systematic error and a lower average scatter (49%). PSFGAN is more tolerant to poor knowledge of the PSF than parametric methods. Our tests show that PSFGAN is robust against a broadening in the PSF width of ±50% if it is trained on multiple PSF's. We demonstrate that while a matched training set does improve performance, we can still subtract point sources using a PSFGAN trained on non-astronomical images. While initial training is computationally expensive, evaluating PSFGAN on data is more than 40 times faster than GALFIT fitting two components. Finally, PSFGAN it is more robust and easy to use than parametric methods as it requires no input parameters.

  18. Situational awareness of hazards: Validation of multi-source radiation measurements

    Science.gov (United States)

    Hultquist, C.; Cervone, G.

    2016-12-01

    Citizen-led movements producing scientific hazard data during disasters are increasingly common. After the Japanese earthquake-triggered tsunami in 2011, and the resulting radioactive releases at the damaged Fukushima Daiichi nuclear power plants, citizens monitored on-ground levels of radiation with innovative mobile devices built from off-the-shelf components. To date, the citizen-led SAFECAST project has recorded 50 million radiation measurements worldwide, with the majority of these measurements from Japan. The analysis of data which are multi-dimensional, not vetted, and provided from multiple devices presents big data challenges due to their volume, velocity, variety, and veracity. While the SAFECAST project produced massive open-source radiation measurements at specific coordinates and times, the reliability and validity of the overall data have not yet been assessed. The nuclear disaster provides a case for assessing the SAFECAST data with official aerial remote sensing radiation data jointly collected by the governments of the United States and Japan. A spatial and statistical assessment of SAFECAST requires several preprocessing steps. First, SAFECAST ionized radiation sensors collected data using different units of measure than the government data, and they had to be converted. Secondly, the normally occurring radiation and decay rates of Cesium from deposition surveys were used to properly compare measurements in space and time. Finally, the GPS located points were selected within overlapping extents at multiple spatial resolutions. Quantitative measures were used to assess the similarity and differences in the observed measurements. Radiation measurements from the same geographic extents show similar spatial variations and statistically significant correlations. The results suggest that actionable scientific data for disasters and emergencies can be inferred from non-traditional and not vetted data generated through citizen science projects. This

  19. Probing dim point sources in the inner Milky Way using PCAT

    Science.gov (United States)

    Daylan, Tansu; Portillo, Stephen K. N.; Finkbeiner, Douglas P.

    2017-01-01

    Poisson regression of the Fermi-LAT data in the inner Milky Way reveals an extended gamma-ray excess. An important question is whether the signal is coming from a collection of unresolved point sources, possibly old recycled pulsars, or constitutes a truly diffuse emission component. Previous analyses have relied on non-Poissonian template fits or wavelet decomposition of the Fermi-LAT data, which find evidence for a population of dim point sources just below the 3FGL flux limit. In order to be able to draw conclusions about the flux distribution of point sources at the dim end, we employ a Bayesian trans-dimensional MCMC framework by taking samples from the space of catalogs consistent with the observed gamma-ray emission in the inner Milky Way. The software implementation, PCAT (Probabilistic Cataloger), is designed to efficiently explore that catalog space in the crowded field limit such as in the galactic plane, where the model PSF, point source positions and fluxes are highly degenerate. We thus generate fair realizations of the underlying MSP population in the inner galaxy and constrain the population characteristics such as the radial and flux distribution of such sources.

  20. Device for forming the image of a radiation source

    International Nuclear Information System (INIS)

    Tosswill, C.H.

    1980-01-01

    An improvement can be made to the space resolution of systems providing the image of a radiation source by means of a slit collimator. In order to do so, a lateral movement of the collimator (with its detectors) is superimposed on the movement of the collimator, in a transversal direction in relation to the transmission direction through the collimator as well as in relation to the walls defining the slits. The total amplitude of the lateral movement is at least equal to the distance between centres of a slit and the following one. In the near field operating system, the lateral movement is a rectilinear movement perpendicular to the walls of the slits. In the distance field operating systems, it is an angular movement about an axis perpendicular to the direction of transmission through the slits [fr

  1. Simulation of the accumulation kinetics for radiation point defects in a metals with impurity

    International Nuclear Information System (INIS)

    Iskakov, B.M.; Nurova, A.B.

    2001-01-01

    In the work a kinetics of vacancies (V) and interstitial atoms (IA) accumulation for cases when the V and IA are recombining with each other, absorbing by drain and capturing by impurity atoms has been simulated. The differential equations system numerical solution was carried out by the Runge-Kutta method. The dynamical equilibrium time achievement for the point radiation defects accumulation process in the metal with impurity is considered

  2. The Schrödinger Equation, the Zero-Point Electromagnetic Radiation, and the Photoelectric Effect

    Science.gov (United States)

    França, H. M.; Kamimura, A.; Barreto, G. A.

    2016-04-01

    A Schrödinger type equation for a mathematical probability amplitude Ψ( x, t) is derived from the generalized phase space Liouville equation valid for the motion of a microscopic particle, with mass M and charge e, moving in a potential V( x). The particle phase space probability density is denoted Q( x, p, t), and the entire system is immersed in the "vacuum" zero-point electromagnetic radiation. We show, in the first part of the paper, that the generalized Liouville equation is reduced to a simpler Liouville equation in the equilibrium limit where the small radiative corrections cancel each other approximately. This leads us to a simpler Liouville equation that will facilitate the calculations in the second part of the paper. Within this second part, we address ourselves to the following task: Since the Schrödinger equation depends on hbar , and the zero-point electromagnetic spectral distribution, given by ρ 0{(ω )} = hbar ω 3/2 π 2 c3, also depends on hbar , it is interesting to verify the possible dynamical connection between ρ 0( ω) and the Schrödinger equation. We shall prove that the Planck's constant, present in the momentum operator of the Schrödinger equation, is deeply related with the ubiquitous zero-point electromagnetic radiation with spectral distribution ρ 0( ω). For simplicity, we do not use the hypothesis of the existence of the L. de Broglie matter-waves. The implications of our study for the standard interpretation of the photoelectric effect are discussed by considering the main characteristics of the phenomenon. We also mention, briefly, the effects of the zero-point radiation in the tunneling phenomenon and the Compton's effect.

  3. Nonpoint and Point Sources of Nitrogen in Major Watersheds of the United States

    Science.gov (United States)

    Puckett, Larry J.

    1994-01-01

    Estimates of nonpoint and point sources of nitrogen were made for 107 watersheds located in the U.S. Geological Survey's National Water-Quality Assessment Program study units throughout the conterminous United States. The proportions of nitrogen originating from fertilizer, manure, atmospheric deposition, sewage, and industrial sources were found to vary with climate, hydrologic conditions, land use, population, and physiography. Fertilizer sources of nitrogen are proportionally greater in agricultural areas of the West and the Midwest than in other parts of the Nation. Animal manure contributes large proportions of nitrogen in the South and parts of the Northeast. Atmospheric deposition of nitrogen is generally greatest in areas of greatest precipitation, such as the Northeast. Point sources (sewage and industrial) generally are predominant in watersheds near cities, where they may account for large proportions of the nitrogen in streams. The transport of nitrogen in streams increases as amounts of precipitation and runoff increase and is greatest in the Northeastern United States. Because no single nonpoint nitrogen source is dominant everywhere, approaches to control nitrogen must vary throughout the Nation. Watershed-based approaches to understanding nonpoint and point sources of contamination, as used by the National Water-Quality Assessment Program, will aid water-quality and environmental managers to devise methods to reduce nitrogen pollution.

  4. Strengthening national infrastructures for the control of radiation sources in Armenia

    International Nuclear Information System (INIS)

    Martirosyan, Ashot; Amirjanyan, Armen

    2008-01-01

    The paper describes the work carried out in Armenia to establish and strengthen regulatory control over radiation sources, including the development of legislation and regulations, the establishment of a national registry of sources, and the development of licensing procedures and training programmes in the area of radiation protection and the safe use of radiation sources. The paper also describes the Regulatory Information System of ANRA, inventarization and licensing process of radiation sources, implementation of the IAEA Code of Conduct on the Safety and Security of Radioactive Sources in Armenia. (author)

  5. The Unicellular State as a Point Source in a Quantum Biological System

    Directory of Open Access Journals (Sweden)

    John S. Torday

    2016-05-01

    Full Text Available A point source is the central and most important point or place for any group of cohering phenomena. Evolutionary development presumes that biological processes are sequentially linked, but neither directed from, nor centralized within, any specific biologic structure or stage. However, such an epigenomic entity exists and its transforming effects can be understood through the obligatory recapitulation of all eukaryotic lifeforms through a zygotic unicellular phase. This requisite biological conjunction can now be properly assessed as the focal point of reconciliation between biology and quantum phenomena, illustrated by deconvoluting complex physiologic traits back to their unicellular origins.

  6. Radiation protection and safety of radiation sources international basic safety standards

    CERN Document Server

    International Atomic Energy Agency. Vienna

    2014-01-01

    The Board of Governors of the IAEA first approved Basic Safety Standards in June 1962; they were published by the IAEA as IAEA Safety Series No. 9. A revised edition was issued in 1967. A third revision was published by the IAEA as the 1982 Edition of IAEA Safety Series No. 9 ; this edition was jointly sponsored by the IAEA, ILO, OECD/NEA and the WHO. The next edition was International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, published by the IAEA as IAEA Safety Series No. 115 in February 1996, and jointly sponsored by the FAO, IAEA, ILO, OECD/NEA, PAHO and the WHO.

  7. Regulation for oil wells logging using ionizing radiation sources. A draft

    International Nuclear Information System (INIS)

    Hidrowoh, Jacob

    2000-01-01

    A project to regulate logging activities using ionizing radiation sources in oil wells in Ecuador is proposed. Its development is based on basic concepts of energy, radiation protection and characteristics of oil exploitation in Ecuador

  8. Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

    Science.gov (United States)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly accomplished by cold biasing the reservoir and using electrical heaters to provide the required control power. Using this method, the loop operating temperature can be controlled within +/- 0.5K. However, because of the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP has been carried out to investigate the effects on the LHP operation when the control temperature sensor is placed on the heat source instead of the reservoir. In these tests, the LHP reservoir is cold-biased and is heated by a control heater. Tests results show that it is feasible to use the heat source temperature for feedback control of the LHP operation. Using this method, the heat source temperature can be maintained within a tight range for moderate and high powers. At low powers, however, temperature oscillations may occur due to interactions among the reservoir control heater power, the heat source mass, and the heat output from the heat source. In addition, the heat source temperature could temporarily deviate from its set point during fast thermal transients. The implication is that more sophisticated feedback control algorithms need to be implemented for LHP transient operation when the heat source temperature is used for feedback control.

  9. KM3NeT/ARCA sensitivity and discovery potential for neutrino point-like sources

    Directory of Open Access Journals (Sweden)

    Trovato A.

    2016-01-01

    Full Text Available KM3NeT is a large research infrastructure with a network of deep-sea neutrino telescopes in the abyss of the Mediterranean Sea. Of these, the KM3NeT/ARCA detector, installed in the KM3NeT-It node of the network, is optimised for studying high-energy neutrinos of cosmic origin. Sensitivities to galactic sources such as the supernova remnant RXJ1713.7-3946 and the pulsar wind nebula Vela X are presented as well as sensitivities to a generic point source with an E−2 spectrum which represents an approximation for the spectrum of extragalactic candidate neutrino sources.

  10. Calculations for Tera-Hertz (THZ) Radiation Sources

    CERN Document Server

    Spencer, James

    2005-01-01

    We explore possibilities for THz sources from 0.3 - 30 THz. While still inaccessible, this broad gap is even wider for advanced acceleration schemes extending from X or, at most, W band RF at the low end up to CO2 lasers. While the physical implementations of these two approaches are quite different, both are proving difficult to develop so that even lower frequency, superconducting RF seems to be the currently preferred means. Similarly, the validity of modelling techniques varies greatly over this range of frequencies but generally mandates coupling Maxwell’s equations to the appropriate device transport physics for which there are many options. Here we calculate radiation from shaped transmission lines using finite-difference, time-domain (FDTD) simulations of Maxwell’s equations coupled to Monte-Carlo techniques for both the production and transport physics of short electron pulses. Examples of THz sources that demonstrate coherent interference effects will be discussed with the goal o...

  11. In vitro unsealed sources. Radiation protection: research sector

    International Nuclear Information System (INIS)

    Fradin, J.; Damiens, A.; Aubert, B.; Celier, D.; Lahaye, T.; Mathieu, P.; Gauron, C.; Barbey, P.; Thieffry, C.; Rigaud, S.; Robert, P.; Labarre, P.; Frot, P.; Testas, F.

    2013-12-01

    This sheet concerns the use of unsealed radioactive sources, and is addressed at experts in radiation protection (PCR), occupational doctors, employers, and researchers and technicians using these techniques. After a brief indication of practice types and of personnel concerned by this risk, the sheet indicates the operational processes, the hazards and risks. It describes how to assess the risk and to determine exposure levels (elements for risk assessment, delimitation of controlled and monitored areas, workstation studies and personnel classification, choice of the dose monitoring method), presents the risk management strategy (risk reduction, technical measures regarding the installation, the instrumentation, and sources, management of wastes and of effluents contaminated by radionuclides, measures regarding the personnel), presents various aspects of medical monitoring (strengthened monitoring, examinations, case of subcontracting companies, case of pregnant or breast feeding women, medical file and post-occupational monitoring). It addresses what must be done in case of incident or dysfunction (premise or equipment contamination, contamination of a person, administrative aspects), mentions the associated biological, chemical, physical and psychological risks. It describes how risk management is to be assessed. A sheet is provided in appendix which describes the general approach to a workstation study

  12. Search for cosmic neutrino point sources with four years of data from the ANTARES telescope

    NARCIS (Netherlands)

    Adrian-Martinez, S.; Al Samarai, I.; Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Astraatmadja, T.; Aubert, J.J.; Baret, B.; Basa, S.; Bertin, V.; Biagi, S.; Bigongiari, C.; Bogazzi, C.; Bou-Cabo, M.; Bouhou, B.; Bouwhuis, M.C.; Brunner, J.; Busto, J.; Capone, A.; Carloganu, C.; Carr, J.; Cecchini, S.; Charif, Z.; Charvis, P.; Chiarusi, T.; Circella, M.; Coniglione, R.; Core, L.; Costantini, H.; Coyle, P.; Creusot, A.; Curtil, C.; De Bonis, G.; Decowski, M.P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Eberl, T.; Emanuele, U.; Enzenhofer, A.; Ernenwein, J.P.; Escoffier, S.; Fehn, K.; Fermani, P.; Ferri, M.; Ferry, S.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.L.; Galata, S.; Gay, P.; Geyer, K.; Giacomelli, G.; Giordano, V.; Gleixner, A.; Gomez-Gonzalez, J.P.; Graf, K.; Guillard, G.; Hallewell, G.; Hamal, M.; van Haren, H.; Heijboer, A.J.; Hello, Y.; Hernandez-Rey, J.J.; Herold, B.; Hossl, J.; Hsu, C.C.; De Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.; Kavatsyuk, O.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Larosa, G.; Lattuada, D.; Leonora, E.; Lefevre, D.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J.A.; Meli, A.; Montaruli, T.; Morganti, M.; Motz, H.; Neff, M.; Nezri, E.; Palioselitis, D.; Pavalas, G.E.; Payet, K.; Petrovic, J.; Piattelli, P.; Popa, V.; Pradier, T.; Presani, E.; Racca, C.; Reed, C.; Riccobene, G.; Richter, R.; Riviere, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Ruiz-Rivas, J.; Rujoiu, M.; Samtleben, D.F.E.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schuller, J.P.; Schussler, F.; Seitz, T.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J.J.M.; Stolarczyk, T.; Sanchez-Losa, A.; Taiuti, M.; Tamburini, C.; Trovato, A.; Vallage, B.; Vallee, C.; Van Elewyck, V.; Vecchi, M.; Vernin, P.; Visser, E.; Wagner, S.; Wijnker, G.; Wilms, J.; de Wolf, E.; Yepes, H.; Zaborov, D.; Zornoza, J.D.; Zuniga, J.

    2012-01-01

    In this paper, a time-integrated search for point sources of cosmic neutrinos is presented using the data collected from 2007 to 2010 by the ANTARES neutrino telescope. No statistically significant signal has been found and upper limits on the neutrino flux have been obtained. Assuming an E-nu(-2).

  13. Distributed Point Source Volcanism: A Mechanism for `Regional Plains' Resurfacing, Venus

    Science.gov (United States)

    Hansen, V. L.; Bleamaster, L. F., III

    2002-03-01

    V23/24 hosts shields that form a thin porous layer across >10x106 km2; variations in thermal gradient/conductivity, radioactive content/distribution, and surface T can result in time transgressive, incipient shallow point-source partial melting.

  14. Estimation of Methane Emissions from Municipal Solid Waste Landfills in China Based on Point Emission Sources

    Directory of Open Access Journals (Sweden)

    Cai Bo-Feng

    2014-01-01

    Citation: Cai, B.-F., Liu, J.-G., Gao, Q.-X., et al., 2014. Estimation of methane emissions from municipal solid waste landfills in China based on point emission sources. Adv. Clim. Change Res. 5(2, doi: 10.3724/SP.J.1248.2014.081.

  15. Effect of varying dispenser point source density on mating disruption of Grapholita molesta (Lepidoptera: Tortricidae).

    Science.gov (United States)

    De Lame, Frédérique M; Epstein, David; Gut, Larry J; Goldfarb, Heidi; Miller, James R

    2010-08-01

    Hand-applied dispensers are successfully used in mating disruption programs, but cost of labor to apply these dispensers limits their adoption. Creating hand-applied dispensers that release larger amounts of pheromone and that can be applied at lower densities per hectare could reduce the cost of mating disruption and increase its use. The effect of reducing the number of point sources per hectare while keeping the amount of pheromone applied per hectare constant on the success of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) mating disruption was investigated with Confuse-OFM, paraffin disk, and Isomate-M Rosso dispensers. For all dispensers, as point source density decreased, numbers of moths captured increased, percentage of orientation disruption to traps decreased, and variability in these measures increased. Decreasing point source density, even while keeping the amount of pheromone applied per hectare constant is not a viable option for reducing the cost of G. molesta mating disruption with hand-applied dispensers. Puffers (aerosol dispensers) are applied at 2.5-5 dispensers per ha for G. molesta control. However, hand-applied dispensers fail when clumped at such low numbers of release sites. Potential explanations for the success of Puffers and the failure of hand-applied dispensers at very low point source densities are presented. The utility of paraffin disk dispensers as experimental devices also is discussed.

  16. Applicability of a desiccant dew-point cooling system independent of external water sources

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Kærn, Martin Ryhl

    2015-01-01

    The applicability of a technical solution for making desiccant cooling systems independent of external water sources is investigated. Water is produced by condensing the desorbed water vapour in a closed regeneration circuit. Desorbed water recovery is applied to a desiccant dew-point cooling...

  17. General Approach to the Evolution of Singlet Nanoparticles from a Rapidly Quenched Point Source

    NARCIS (Netherlands)

    Feng, J.; Huang, Luyi; Ludvigsson, Linus; Messing, Maria; Maiser, A.; Biskos, G.; Schmidt-Ott, A.

    2016-01-01

    Among the numerous point vapor sources, microsecond-pulsed spark ablation at atmospheric pressure is a versatile and environmentally friendly method for producing ultrapure inorganic nanoparticles ranging from singlets having sizes smaller than 1 nm to larger agglomerated structures. Due to its fast

  18. Pollutant runoff from non-point sources and its estimation by runoff models.

    Science.gov (United States)

    Noguchi, M; Hiwatashi, T; Mizuno, Y; Minematsu, M

    2002-01-01

    In order to attain a sound and sustainable water environment, it is important to carry out the environmental management of the watershed. For this purpose, knowledge on the pollutant runoff mechanism from non-point sources becomes very important especially under rainy conditions. At Isahaya, Nagasaki, Japan, a big project of construction of sea-dyke and reclamation is now going on, so reducing the pollutant runoff, especially from non-point sources, becomes more important. Some runoff models of rainwater are developed to predict the rate of pollutant loads from the non-point sources, and their results are compared with each other to investigate the accuracy of prediction. In this paper, runoff analysis of both rainwater and pollutants has been carried out using three models: the tank model, the kinematic wave (K-W) model, and a model using the digital elevation model (DEM). For precise estimation, it becomes necessary to identify the parameters included in these models. Here, total nitrogen has been considered as pollutants, and detachment rates are evaluated, correlated with a class of land use, soil type, and moisture content. Finally, it has been shown that pollutant runoff from non-point sources can be predicted fairly well, identifying the model parameter appropriately.

  19. Temporal - spatial dynamics of vegetation variation on non - point source nutrient pollution

    NARCIS (Netherlands)

    Ouyang, Wei; Xuelei Wang,; Hao, Fanghua; Srinivasan, R.

    2009-01-01

    The temporal-spatial interaction of land cover and non-point source (NPS) nutrient pollution were analyzed with the Soil and Water Assessment Tool (SWAT) to simulate the temporal-spatial features of NPS nutrient loading in the upper stream of the Yellow River catchment. The corresponding land cover

  20. Nanoscale structuring of tungsten tip yields most coherent electron point-source

    International Nuclear Information System (INIS)

    Mutus, Josh Y; Livadaru, Lucian; Urban, Radovan; Pitters, Jason; Peter Legg, A; Salomons, Mark H; Cloutier, Martin; Wolkow, Robert A

    2013-01-01

    This report demonstrates the most spatially-coherent electron source ever reported. A coherence angle of 14.3 ± 0.5° was measured, indicating a virtual source size of 1.7 ± 0.6 Å using an extraction voltage of 89.5 V. The nanotips under study were crafted using a spatially-confined, field-assisted nitrogen etch which removes material from the periphery of the tip apex resulting in a sharp, tungsten–nitride stabilized, high-aspect ratio source. The coherence properties are deduced from holographic measurements in a low-energy electron point source microscope with a carbon nanotube bundle as sample. Using the virtual source size and emission current the brightness normalized to 100 kV is found to be 7.9 × 10 8 A sr −1 cm 2 . (paper)

  1. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...... modulation (PWM) strategies for controlling the Z-source NPC inverter. While developing the PWM techniques, attention has been devoted to carefully derive them from a common generic basis for improved portability, easier implementation, and most importantly, assisting readers in understanding all concepts...

  2. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    modulation (PWM) strategies for controlling the Z-source NPC inverter. While developing the PWM techniques, attention has been devoted to carefully derive them from a common generic basis for improved portability, easier implementation, and most importantly, assisting readers in understanding all concepts......Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...

  3. The Potential for Electrofuels Production in Sweden Utilizing Fossil and Biogenic CO2 Point Sources

    International Nuclear Information System (INIS)

    Hansson, Julia; Hackl, Roman; Taljegard, Maria; Brynolf, Selma; Grahn, Maria

    2017-01-01

    This paper maps, categorizes, and quantifies all major point sources of carbon dioxide (CO 2 ) emissions from industrial and combustion processes in Sweden. The paper also estimates the Swedish technical potential for electrofuels (power-to-gas/fuels) based on carbon capture and utilization. With our bottom-up approach using European databases, we find that Sweden emits approximately 50 million metric tons of CO 2 per year from different types of point sources, with 65% (or about 32 million tons) from biogenic sources. The major sources are the pulp and paper industry (46%), heat and power production (23%), and waste treatment and incineration (8%). Most of the CO 2 is emitted at low concentrations (<15%) from sources in the southern part of Sweden where power demand generally exceeds in-region supply. The potentially recoverable emissions from all the included point sources amount to 45 million tons. If all the recoverable CO 2 were used to produce electrofuels, the yield would correspond to 2–3 times the current Swedish demand for transportation fuels. The electricity required would correspond to about 3 times the current Swedish electricity supply. The current relatively few emission sources with high concentrations of CO 2 (>90%, biofuel operations) would yield electrofuels corresponding to approximately 2% of the current demand for transportation fuels (corresponding to 1.5–2 TWh/year). In a 2030 scenario with large-scale biofuels operations based on lignocellulosic feedstocks, the potential for electrofuels production from high-concentration sources increases to 8–11 TWh/year. Finally, renewable electricity and production costs, rather than CO 2 supply, limit the potential for production of electrofuels in Sweden.

  4. Transition radiation in metal-metal multilayer nanostructures as a medical source of hard x-ray radiation

    International Nuclear Information System (INIS)

    Pokrovsky, A. L.; Kaplan, A. E.; Shkolnikov, P. L.

    2006-01-01

    We show that a periodic metal-metal multilayer nanostructure can serve as an efficient source of hard x-ray transition radiation. Our research effort is aimed at developing an x-ray source for medical applications, which is based on using low-energy relativistic electrons. The approach toward choosing radiator-spacer couples for the generation of hard x-ray resonant transition radiation by few-MeV electrons traversing solid multilayer structures for the energies of interest to medicine (30-50 keV) changes dramatically compared with that for soft x-ray radiation. We show that one of the main factors in achieving the required resonant line is the absence of the contrast of the refractive indices between the spacer and the radiator at the far wings of the radiation line; for that purpose, the optimal spacer, as a rule, should have a higher atomic number than the radiator. Having experimental goals in mind, we have considered also the unwanted effects due to bremsstrahlung radiation, absorption and scattering of radiated photons, detector-related issues, and inhibited coherence of transition radiation due to random deviation of spacing between the layers. Choosing as a model example a Mo-Ag radiator-spacer pair of materials, we demonstrate that the x-ray transition radiation line can be well resolved with the use of spatial and frequency filtering

  5. Motion of a point charge in electromagnetic fields under consideration of radiation damping

    International Nuclear Information System (INIS)

    Stoeckel, H.

    1976-01-01

    The 'new equation' of Mo and Papas for the description of a point charge in an electromagnetic field under consideration of radiation damping, published in 1971, doesn't show the known disadvantages of the Lorentz-Dirac equation, taken as a basis up to now. Different forms of the Mo-Papas equation are derived and the resulting force- and power-balances are discussed. Exact and approximated solutions are derived for simple given fields, for instance for a homogeneous magnetic field, a homogeneous electric field and for the field of a resting point charge. The scattering angles are calculated for the scattering of a point charge by a homogeneous magnetic resp. electric field of finite extension. The results agree well with approximation formulas of other authors. (author)

  6. Fast cine-magnetic resonance imaging point tracking for prostate cancer radiation therapy planning

    International Nuclear Information System (INIS)

    Dowling, J; Chandra, S; Dang, K; Fox, Chris D; Gill, Suki; Kron, T; Pham, D; Foroudi, F

    2014-01-01

    The analysis of intra-fraction organ motion is important for improving the precision of radiation therapy treatment delivery. One method to quantify this motion is for one or more observers to manually identify anatomic points of interest (POIs) on each slice of a cine-MRI sequence. However this is labour intensive and inter- and intra- observer variation can introduce uncertainty. In this paper a fast method for non-rigid registration based point tracking in cine-MRI sagittal and coronal series is described which identifies POIs in 0.98 seconds per sagittal slice and 1.35 seconds per coronal slice. The manual and automatic points were highly correlated (r>0.99, p<0.001) for all organs and the difference generally less than 1mm. For prostate planning peristalsis and rectal gas can result in unpredictable out of plane motion, suggesting the results may require manual verification.

  7. Fast cine-magnetic resonance imaging point tracking for prostate cancer radiation therapy planning

    Science.gov (United States)

    Dowling, J.; Dang, K.; Fox, Chris D.; Chandra, S.; Gill, Suki; Kron, T.; Pham, D.; Foroudi, F.

    2014-03-01

    The analysis of intra-fraction organ motion is important for improving the precision of radiation therapy treatment delivery. One method to quantify this motion is for one or more observers to manually identify anatomic points of interest (POIs) on each slice of a cine-MRI sequence. However this is labour intensive and inter- and intra- observer variation can introduce uncertainty. In this paper a fast method for non-rigid registration based point tracking in cine-MRI sagittal and coronal series is described which identifies POIs in 0.98 seconds per sagittal slice and 1.35 seconds per coronal slice. The manual and automatic points were highly correlated (r>0.99, pmanual verification.

  8. Tackling non-point source water pollution in British Columbia : an action plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    British Columbia`s approach to water quality management is discussed. The BC efforts include regulating `end of pipe` point discharges from industrial and municipal outfalls. The major remaining cause of water pollution is from non-point sources (NPS). NPS water pollution is caused by the release of pollutants from different and diffuse sources, mostly unregulated and associated with urbanization, agriculture and other forms of land development. The importance of dealing with such problems on an immediate basis to avoid a decline in water quality in the province is emphasized. Major sources of water pollution in British Columbia include: land development, agriculture, storm water runoff, onsite sewage systems, forestry, atmospheric deposition, and marine activities. 3 tabs.

  9. The effect of agricultural non-point Source Pollution of nitrogen and phosphorous on Lake Eutrophication

    Science.gov (United States)

    Xiong, Hanfeng

    2017-05-01

    Based on the data from investigation, the evaluation by equal standard pollution loading method was used to study the agricultural non-point source pollution caused by nitrogen and phosphorous from livestock’s feces pollution, chemical fertilizer pollution and fish breeding pond pollution in Liangzi Lake wetland. The results revealed that: The lost amount of nitrogen and phosphorous was separately 1276.49T, 103.04T; the equivalent standard pollution loading amount was separately 12.76X108 m3, 5.15X108 m3. The lost amount of nitrogen was highest in chemical fertilizer. Based pollution on the understanding of the cause of agricultural non-point source in Liangzi Lake wetland, some countermeasures were suggested according to different pollution source.

  10. Strategies for satellite-based monitoring of CO2 from distributed area and point sources

    Science.gov (United States)

    Schwandner, Florian M.; Miller, Charles E.; Duren, Riley M.; Natraj, Vijay; Eldering, Annmarie; Gunson, Michael R.; Crisp, David

    2014-05-01

    Atmospheric CO2 budgets are controlled by the strengths, as well as the spatial and temporal variabilities of CO2 sources and sinks. Natural CO2 sources and sinks are dominated by the vast areas of the oceans and the terrestrial biosphere. In contrast, anthropogenic and geogenic CO2 sources are dominated by distributed area and point sources, which may constitute as much as 70% of anthropogenic (e.g., Duren & Miller, 2012), and over 80% of geogenic emissions (Burton et al., 2013). Comprehensive assessments of CO2 budgets necessitate robust and highly accurate satellite remote sensing strategies that address the competing and often conflicting requirements for sampling over disparate space and time scales. Spatial variability: The spatial distribution of anthropogenic sources is dominated by patterns of production, storage, transport and use. In contrast, geogenic variability is almost entirely controlled by endogenic geological processes, except where surface gas permeability is modulated by soil moisture. Satellite remote sensing solutions will thus have to vary greatly in spatial coverage and resolution to address distributed area sources and point sources alike. Temporal variability: While biogenic sources are dominated by diurnal and seasonal patterns, anthropogenic sources fluctuate over a greater variety of time scales from diurnal, weekly and seasonal cycles, driven by both economic and climatic factors. Geogenic sources typically vary in time scales of days to months (geogenic sources sensu stricto are not fossil fuels but volcanoes, hydrothermal and metamorphic sources). Current ground-based monitoring networks for anthropogenic and geogenic sources record data on minute- to weekly temporal scales. Satellite remote sensing solutions would have to capture temporal variability through revisit frequency or point-and-stare strategies. Space-based remote sensing offers the potential of global coverage by a single sensor. However, no single combination of orbit

  11. Development of quality assurance program for production of sealed radiation source

    CERN Document Server

    Nam, J H; Cho, W K; Han, H S; Hong, S B; Kim, K H; Kim, S D; Lee, Y G; Lim, N J

    2001-01-01

    The quality assurance program for production of sealed radiation sources has been developed to increase the efficiency and safety of production work and to meet the demand of the customers. The quality assurance program are applied to the entire work scope of the production of sealed radiation sources. Every workers related to the production of sealed radiation sources will be required to follow this quality assurance program. It is expected that the sealed radiation source products produced according to this quality assurance program can meet the regulatory requirements, customer's demand and have good competitiveness in the domestic and world markets.

  12. Location of acoustic radiators and inversion for energy density using radio-frequency sources and thunder recordings

    Science.gov (United States)

    Anderson, J.; Johnson, J. B.; Arechiga, R. O.; Edens, H. E.; Thomas, R. J.

    2011-12-01

    We use radio frequency (VHF) pulse locations mapped with the New Mexico Tech Lightning Mapping Array (LMA) to study the distribution of thunder sources in lightning channels. A least squares inversion is used to fit channel acoustic energy radiation with broadband (0.01 to 500 Hz) acoustic recordings using microphones deployed local (lightning. We model the thunder (acoustic) source as a superposition of line segments connecting the LMA VHF pulses. An optimum branching algorithm is used to reconstruct conductive channels delineated by VHF sources, which we discretize as a superposition of finely-spaced (0.25 m) acoustic point sources. We consider total radiated thunder as a weighted superposition of acoustic waves from individual channels, each with a constant current along its length that is presumed to be proportional to acoustic energy density radiated per unit length. Merged channels are considered as a linear sum of current-carrying branches and radiate proportionally greater acoustic energy. Synthetic energy time series for a given microphone location are calculated for each independent channel. We then use a non-negative least squares inversion to solve for channel energy densities to match the energy time series determined from broadband acoustic recordings across a 4-station microphone network. Events analyzed by this method have so far included 300-1000 VHF sources, and correlations as high as 0.5 between synthetic and recorded thunder energy were obtained, despite the presence of wind noise and 10-30 m uncertainty in VHF source locations.

  13. Source ranging with an underwater geographic point in non-cooperative bistatic sonar

    Science.gov (United States)

    Lee, Donghwa; Jung, Tae Jin; Lee, Kyun Kyung; Myung, Hyun

    2014-01-01

    Active sonar is divided into monostatic and bistatic sonar according to the relative positions of the source and the receiver. Bistatic sonar on modern submarines is classified into cooperative and non-cooperative operations. Cooperative operation uses an active signal of a friendly ship; therefore, source information is known a priori, whereas non-cooperative operation utilizes an active signal of the enemy, and hence, it is difficult to acquire source information, such as a source range, which is important for bistatic sonar operation. In order to overcome this difficulty, this paper proposes an estimation method for the source range that employs geographic information, and the utility of the source range estimation is evaluated. For the evaluation, we consider three error components. Then, the validity of the scheme is confirmed through theoretical error analysis and simulation study. The results show that geographic points that satisfy certain specific conditions can be used to estimate the source range within a range of tens of km in the simulation. Finally, we confirm that the receiver could estimate the source range from far away using non-cooperative bistatic sonar.

  14. Global Pollution of Surface Waters from Point and Nonpoint Sources of Nitrogen

    Directory of Open Access Journals (Sweden)

    G. van Drecht

    2001-01-01

    Full Text Available Global 0.5- by 0.5-degree resolution estimates are presented on the fate of nitrogen (N stemming from point and nonpoint sources, including plant uptake, denitrification, leaching from the rooting zone, rapid flow through shallow groundwater, and slow flow through deep groundwater to riverine systems. Historical N inputs are used to describe the N flows in groundwater. For nonpoint N sources (agricultural and natural ecosystems, calculations are based on local hydrology, climate, geology, soils, climate and land use combined with data for 1995 on crop production, N inputs from N fertilizers and animal manure, and estimates for ammonia emissions, biological N fixation, and N deposition. For point sources, our estimates are based on population densities and human N emissions, sanitation, and treatment. The results provide a first insight into the magnitude of the N losses from soil-plant systems and point sources in various parts of the world, and the fate of N during transport in atmosphere, groundwater, and surface water. The contribution to the river N load by anthropogenic N pollution is dominant in many river basins in Europe, Asia, and North Africa. Our model results explain much of the variation in measured N export from different world river basins.

  15. A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Aab, A. [Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud Universiteit, Nijmegen (Netherlands); Abreu, P. [Laboratório de Instrumentação e Física Experimental de Partículas—LIP and Instituto Superior Técnico—IST, Universidade de Lisboa—UL, Lisbon (Portugal); Aglietta, M. [INFN, Sezione di Torino, Torino (Italy); Samarai, I. Al [Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3, Paris (France); Albuquerque, I. F. M. [Universidade de São Paulo, Inst. de Física, São Paulo (Brazil); Allekotte, I. [Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Almela, A. [Instituto de Tecnologías en Detección y Astropartículas (CNEA, CONICET, UNSAM), Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, Buenos Aires (Argentina); Castillo, J. Alvarez [Universidad Nacional Autónoma de México, México, D. F., México (Mexico); Alvarez-Muñiz, J. [Universidad de Santiago de Compostela, La Coruña (Spain); Anastasi, G. A. [Gran Sasso Science Institute (INFN), L’Aquila (Italy); and others

    2017-03-10

    Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p -values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictions of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.

  16. Using Soluble Reactive Phosphorus and Ammonia to Identify Point Source Discharge from Large Livestock Facilities

    Science.gov (United States)

    Borrello, M. C.; Scribner, M.; Chessin, K.

    2013-12-01

    A growing body of research draws attention to the negative environmental impacts on surface water from large livestock facilities. These impacts are mostly in the form of excessive nutrient loading resulting in significantly decreased oxygen levels. Over-application of animal waste on fields as well as direct discharge into surface water from facilities themselves has been identified as the main contributor to the development of hypoxic zones in Lake Erie, Chesapeake Bay and the Gulf of Mexico. Some regulators claim enforcement of water quality laws is problematic because of the nature and pervasiveness of non-point source impacts. Any direct discharge by a facility is a violation of permits governed by the Clean Water Act, unless the facility has special dispensation for discharge. Previous research by the principal author and others has shown runoff and underdrain transport are the main mechanisms by which nutrients enter surface water. This study utilized previous work to determine if the effects of non-point source discharge can be distinguished from direct (point-source) discharge using simple nutrient analysis and dissolved oxygen (DO) parameters. Nutrient and DO parameters were measured from three sites: 1. A stream adjacent to a field receiving manure, upstream of a large livestock facility with a history of direct discharge, 2. The same stream downstream of the facility and 3. A stream in an area relatively unimpacted by large-scale agriculture (control site). Results show that calculating a simple Pearson correlation coefficient (r) of soluble reactive phosphorus (SRP) and ammonia over time as well as temperature and DO, distinguishes non-point source from point source discharge into surface water. The r value for SRP and ammonia for the upstream site was 0.01 while the r value for the downstream site was 0.92. The control site had an r value of 0.20. Likewise, r values were calculated on temperature and DO for each site. High negative correlations

  17. Novel particle and radiation sources and advanced materials

    Science.gov (United States)

    Mako, Frederick

    2016-03-01

    The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and "green" klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

  18. OCO-2 Detection of Atmospheric Carbon Dioxide Variability over Natural and Anthropogenic Point-Sources

    Science.gov (United States)

    Schwandner, F. M.; Gunson, M. R.; Miller, C. E.; Carn, S. A.; Eldering, A.; Krings, T.; Verhulst, K. R.; Schimel, D.; Nguyen, H.; Crisp, D.; O'Dell, C.; Osterman, G. B.; Iraci, L. T.; Podolske, J. R.

    2017-12-01

    Natural and anthropogenic emissions of carbon dioxide (CO2) to the atmosphere vary temporally and spatially at the 0.1-10 kilometer-scale. Plumes from regional and point-scale emission sources may be discernable from space within their spatial context but the characteristics of aging plumes may pose additional challenges to quantification and attribution. Space-borne measurements by NASA's Orbiting Carbon Observatory-2 (OCO-2) expose distinct structures of atmospheric carbon dioxide on kilometer scales over known anthropogenic and natural point sources. Urban areas, including megacities, account for over 70% of anthropogenic CO2 emissions. In cities, CO2 emitted from dense clusters of mobile and stationary point sources may form persistent CO2 enhancements producing urban CO2 domes. OCO-2 measurements cross the Los Angeles basin several times a year consistently show enhancements in the column average CO2 dry air mole fraction, XCO2, with highest values over the urban core and decreasing through suburban areas to rural background values, with a seasonally variability of 4.4 to 6.1 ppm. For natural point sources, volcanoes may emit CO2 continuously but variably, at source strengths similar to fossil-fuel burning power plants. An OCO-2 transect passing directly downwind of the persistent isolated natural CO2 plume emanating from Yasur volcano (Vanuatu) produces a narrow strand of enhanced XCO2 values (ΔXCO2 3.4 ppm). Gaussian plume modeling of this plume is consistent with a 41.6 kt d-1 CO2 point source. Additional plume detections over Aoba and Ambrym volcanoes (Vanuatu) show similar results. This first quantitative space-borne volcanic CO2 plume flux estimate puts volcanic CO2 emissions into context: the largest continuous volcanic CO2 emitters on Earth are similar in source strength to a large coal fired power plant, but barely reach the lower end of the range of the 70 largest fossil-fuel burning power plants on Earth, which themselves are dwarfed by megacity

  19. Atmospheric observations for quantifying emissions of point-source synthetic greenhouse gases (CF4, NF3 and HFC-23)

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair J.; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Fraser, Paul J.; Mitrevski, Blagoj; Steele, L. Paul; Krummel, Paul B.; Mühle, Jens; Weiss, Ray F.

    2016-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacement compounds that are emitted from fugitive and mobile emission sources, these gases are largely emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane factories (HFC-23). In this work we show the potential for atmospheric measurements to understand regional sources of these gases and to highlight emission 'hotspots'. We target our analysis on measurements from two Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites that are particularly sensitive to regional emissions of these gases: Gosan on Jeju Island in the Republic of Korea and Cape Grim on Tasmania in Australia. These sites measure CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over a decade (2005-2015) at high spatial resolution. At present these gases make a small contribution to global radiative forcing, however, given that their impact could rise significantly and that point sources of such gases can be mitigated, atmospheric monitoring could be an important tool for aiding emissions reduction policy.

  20. Search for Cosmic Neutrino Point Sources with Four Years of Data from the ANTARES Telescope

    Science.gov (United States)

    Adrián-Martínez, S.; Samarai, I. Al; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Astraatmadja, T.; Aubert, J.-J.; Baret, B.; Basa, S.; Bertin, V.; Biagi, S.; Bigongiari, C.; Bogazzi, C.; Bou-Cabo, M.; Bouhou, B.; Bouwhuis, M. C.; Brunner, J.; Busto, J.; Capone, A.; Cârloganu, C.; Carr, J.; Cecchini, S.; Charif, Z.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Coniglione, R.; Core, L.; Costantini, H.; Coyle, P.; Creusot, A.; Curtil, C.; De Bonis, G.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Eberl, T.; Emanuele, U.; Enzenhöfer, A.; Ernenwein, J.-P.; Escoffier, S.; Fehn, K.; Fermani, P.; Ferri, M.; Ferry, S.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatà, S.; Gay, P.; Geyer, K.; Giacomelli, G.; Giordano, V.; Gleixner, A.; Gómez-González, J. P.; Graf, K.; Guillard, G.; Hallewell, G.; Hamal, M.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hsu, C. C.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.; Kavatsyuk, O.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Larosa, G.; Lattuada, D.; Leonora, E.; Lefèvre, D.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martínez-Mora, J. A.; Meli, A.; Montaruli, T.; Morganti, M.; Motz, H.; Neff, M.; Nezri, E.; Palioselitis, D.; Păvălaş, G. E.; Payet, K.; Petrovic, J.; Piattelli, P.; Popa, V.; Pradier, T.; Presani, E.; Racca, C.; Reed, C.; Riccobene, G.; Richter, R.; Rivière, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Ruiz-Rivas, J.; Rujoiu, M.; Samtleben, D. F. E.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schuller, J.-P.; Schüssler, F.; Seitz, T.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Tamburini, C.; Trovato, A.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vecchi, M.; Vernin, P.; Visser, E.; Wagner, S.; Wijnker, G.; Wilms, J.; de Wolf, E.; Yepes, H.; Zaborov, D.; Zornoza, J. D.; Zúñiga, J.

    2012-11-01

    In this paper, a time-integrated search for point sources of cosmic neutrinos is presented using the data collected from 2007 to 2010 by the ANTARES neutrino telescope. No statistically significant signal has been found and upper limits on the neutrino flux have been obtained. Assuming an E -2 ν spectrum, these flux limits are at 1-10 ×10-8 GeV cm-2 s-1 for declinations ranging from -90° to 40°. Limits for specific models of RX J1713.7-3946 and Vela X, which include information on the source morphology and spectrum, are also given.

  1. LEAP: Looking beyond pixels with continuous-space EstimAtion of Point sources

    Science.gov (United States)

    Pan, Hanjie; Simeoni, Matthieu; Hurley, Paul; Blu, Thierry; Vetterli, Martin

    2017-12-01

    Context. Two main classes of imaging algorithms have emerged in radio interferometry: the CLEAN algorithm and its multiple variants, and compressed-sensing inspired methods. They are both discrete in nature, and estimate source locations and intensities on a regular grid. For the traditional CLEAN-based imaging pipeline, the resolution power of the tool is limited by the width of the synthesized beam, which is inversely proportional to the largest baseline. The finite rate of innovation (FRI) framework is a robust method to find the locations of point-sources in a continuum without grid imposition. The continuous formulation makes the FRI recovery performance only dependent on the number of measurements and the number of sources in the sky. FRI can theoretically find sources below the perceived tool resolution. To date, FRI had never been tested in the extreme conditions inherent to radio astronomy: weak signal / high noise, huge data sets, large numbers of sources. Aims: The aims were (i) to adapt FRI to radio astronomy, (ii) verify it can recover sources in radio astronomy conditions with more accurate positioning than CLEAN, and possibly resolve some sources that would otherwise be missed, (iii) show that sources can be found using less data than would otherwise be required to find them, and (iv) show that FRI does not lead to an augmented rate of false positives. Methods: We implemented a continuous domain sparse reconstruction algorithm in Python. The angular resolution performance of the new algorithm was assessed under simulation, and with visibility measurements from the LOFAR telescope. Existing catalogs were used to confirm the existence of sources. Results: We adapted the FRI framework to radio interferometry, and showed that it is possible to determine accurate off-grid point-source locations and their corresponding intensities. In addition, FRI-based sparse reconstruction required less integration time and smaller baselines to reach a comparable

  2. An Ultradeep Chandra Catalog of X-Ray Point Sources in the Galactic Center Star Cluster

    Science.gov (United States)

    Zhu, Zhenlin; Li, Zhiyuan; Morris, Mark R.

    2018-04-01

    We present an updated catalog of X-ray point sources in the inner 500″ (∼20 pc) of the Galactic center (GC), where the nuclear star cluster (NSC) stands, based on a total of ∼4.5 Ms of Chandra observations taken from 1999 September to 2013 April. This ultradeep data set offers unprecedented sensitivity for detecting X-ray sources in the GC, down to an intrinsic 2–10 keV luminosity of 1.0 × 1031 erg s‑1. A total of 3619 sources are detected in the 2–8 keV band, among which ∼3500 are probable GC sources and ∼1300 are new identifications. The GC sources collectively account for ∼20% of the total 2–8 keV flux from the inner 250″ region where detection sensitivity is the greatest. Taking advantage of this unprecedented sample of faint X-ray sources that primarily traces the old stellar populations in the NSC, we revisit global source properties, including long-term variability, cumulative spectra, luminosity function, and spatial distribution. Based on the equivalent width and relative strength of the iron lines, we suggest that in addition to the arguably predominant population of magnetic cataclysmic variables (CVs), nonmagnetic CVs contribute substantially to the detected sources, especially in the lower-luminosity group. On the other hand, the X-ray sources have a radial distribution closely following the stellar mass distribution in the NSC, but much flatter than that of the known X-ray transients, which are presumably low-mass X-ray binaries (LMXBs) caught in outburst. This, together with the very modest long-term variability of the detected sources, strongly suggests that quiescent LMXBs are a minor (less than a few percent) population.

  3. Estimated radiation dose and image quality comparison of the scan protocols in dual-source computed tomography coronary angiography.

    Science.gov (United States)

    Karaarslan, Ercan; Ulus, Sıla; Bavbek, Cengiz

    2013-08-01

    Radiation exposure from computed tomography coronary angiography (CTCA) is of particular concern and several techniques have been introduced to lower the radiation dose. In this study, we aimed to compare the diagnostic image quality and estimated radiation dose of the three CTCA acquisition protocols in a recently introduced second generation dual-source computed tomography. Two hundred consecutive subjects underwent dual-source CTCA by using high-pitch spiral, sequential and retrospective spiral protocols. Effective radiation dose, expressed in millisieverts, was calculated as the product of the dose-length product times a conversion factor of 0.014. Image quality was evaluated on a per-segment basis, with a four-point scale. For the high-pitch spiral, sequential and retrospective spiral protocols, mean effective radiation doses were 1.41 ± 0.56, 5.50 ± 2.06 and 7.79 ± 2.25 mSv and mean per-subject image scores were 2.8 ± 0.7, 2.2 ± 0.8 and 2.5 ± 0.8, respectively. Radiation dose of the high-pitch mode was significantly lower (P quality revealed a significant difference between the high-pitch spiral and the sequential modes (P source CTCA using high-pitch acquisition considerably lowers radiation exposure in subjects with a low and stable heart rate and maintains good image quality, especially when the subjects have a body mass index ≤25 and a tube voltage of 80 or 100 kV is used. However, when sequential and retrospective spiral modes are used in the same device, mean radiation doses can increase roughly three and five times more, respectively. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  4. Radiological protection, safety and security issues in the industrial and medical applications of radiation sources

    International Nuclear Information System (INIS)

    Vaz, Pedro

    2015-01-01

    The use of radiation sources, namely radioactive sealed or unsealed sources and particle accelerators and beams is ubiquitous in the industrial and medical applications of ionizing radiation. Besides radiological protection of the workers, members of the public and patients in routine situations, the use of radiation sources involves several aspects associated to the mitigation of radiological or nuclear accidents and associated emergency situations. On the other hand, during the last decade security issues became burning issues due to the potential malevolent uses of radioactive sources for the perpetration of terrorist acts using RDD (Radiological Dispersal Devices), RED (Radiation Exposure Devices) or IND (Improvised Nuclear Devices). A stringent set of international legally and non-legally binding instruments, regulations, conventions and treaties regulate nowadays the use of radioactive sources. In this paper, a review of the radiological protection issues associated to the use of radiation sources in the industrial and medical applications of ionizing radiation is performed. The associated radiation safety issues and the prevention and mitigation of incidents and accidents are discussed. A comprehensive discussion of the security issues associated to the global use of radiation sources for the aforementioned applications and the inherent radiation detection requirements will be presented. Scientific, technical, legal, ethical, socio-economic issues are put forward and discussed. - Highlights: • The hazards associated to the use of radioactive sources must be taken into account. • Security issues are of paramount importance in the use of radioactive sources. • Radiation sources can be used to perpetrate terrorist acts (RDDs, INDs, REDs). • DSRS and orphan sources trigger radiological protection, safety and security concerns. • Regulatory control, from cradle to grave, of radioactive sources is mandatory.

  5. Disk shaped radiation sources fabricated by compression and formation of sinter powder

    International Nuclear Information System (INIS)

    Kawano, Takao

    2008-01-01

    Sinters are deposits found at the bottom of hot springs, some of which contain naturally occurring radioisotopes of the uranium and thorium series. A disk-shaped radiation source was developed by compressing sinter powder. Ten disk-shaped radiation sources were fabricated by this method and their weight, thickness, mass density, and radioactivity were determined. The results indicated that special skills or techniques are not required for production of a radiation source with this method, and the production method is robust. Thus, the method is suitable for the simultaneous fabrication of multiple uniform radiation sources. To evaluate the ability of this fabrication method to produce sinter radiation sources applicable to courses involving radiation protection or similar investigations, the dependence of the radiation count rate on distance, shielding thickness, and shielding materials was examined using a conventional GM survey meter. The results showed that the sinter radiation source is suitable to comprehend characteristics of radiation and principle of radiation protection related to distance and shielding. (author)

  6. Educational advertising of the public about the use of radiation sources in technology, research and medicine

    International Nuclear Information System (INIS)

    Stolar, A.

    2009-01-01

    At the latest since Tschernobyl the use of radiation sources and ionizing radiation is due to missing knowledge of the public not affected by popularity but rather by fear. But the question is, whether it would be necessary on the part of the radiation users, not to conceal or mythologise the use, but to emphasize on educational advertising. (orig.)

  7. A point-source norovirus outbreak caused by exposure to fomites.

    Science.gov (United States)

    Repp, Kimberly K; Keene, William E

    2012-06-01

    We investigated a norovirus outbreak (genotype GII.2) affecting 9 members of a soccer team. Illness was associated with touching a reusable grocery bag or consuming its packaged food contents (risk difference, 0.636; P fomites can lead to subsequent point-source outbreaks. When feasible, we recommend dedicated bathrooms for sick persons and informing cleaning staff (professional or otherwise) about the need for adequate environmental sanitation of surfaces and fomites to prevent spread.

  8. CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

    International Nuclear Information System (INIS)

    Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar

    2002-01-01

    The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

  9. Gamma Rays from the Inner Milky Way: Dark Matter or Point Sources?

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Studies of data from the Fermi Gamma-Ray Space Telescope have revealed bright gamma-ray emission from the central regions of our galaxy, with a spatial and spectral profile consistent with annihilating dark matter. I will present a new model-independent analysis that suggests that rather than originating from dark matter, the GeV excess may arise from a surprising new population of as-yet-unresolved gamma-ray point sources in the heart of the Milky Way.

  10. Magnetic point sources in three dimensional Brans-Dicke gravity theories

    OpenAIRE

    Dias, Oscar J. C.; Lemos, Jose' P. S.

    2002-01-01

    We obtain geodesically complete spacetimes generated by static and rotating magnetic point sources in an Einstein-Maxwell-Dilaton theory of the Brans-Dicke type in three dimensions (3D). The theory is specified by three fields, the dilaton, the graviton and the electromagnetic field, and two parameters, the cosmological constant and the Brans-Dicke parameter, w. When the Brans-Dicke parameter is infinity, our solution reduces to the magnetic counterpart of the BTZ solution, while the w=0 case...

  11. Prevention and Control of Agricultural Non-Point Source Pollutions in UK and Suggestions to China

    OpenAIRE

    Liu, Kun; Ren, Tianzhi; Wu, Wenliang; Meng, Fanquiao; Bellarby, Jessica; Smith, Laurence

    2016-01-01

    Currently, the world is facing challenges of maintaining food production growth while improving agricultural ecological environmental quality. The prevention and control of agricultural non-point source pollution, a key component of these challenges, is a systematic program which integrates many factors such as technology and its extension, relevant regulation and policies. In the project of UK-China Sustainable Agriculture Innovation Network, we undertook a comprehensive analysis of the prev...

  12. Simulations of HXR Foot-point Source Sizes for Modified Thick-target Models

    Czech Academy of Sciences Publication Activity Database

    Moravec, Z.; Varady, Michal; Karlický, Marian; Kašparová, Jana

    2013-01-01

    Roč. 37, č. 2 (2013), s. 535-540 ISSN 1845-8319. [Hvar Astrophysical Colloquium /12./. Hvar, 03.09.2012-07.09.2012] R&D Projects: GA ČR GAP209/10/1680; GA ČR GAP209/12/0103 Institutional support: RVO:67985815 Keywords : solar flares * hard X-rays * foot-point sources Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  13. Performance of Different Light Sources for the Absolute Calibration of Radiation Thermometers

    Science.gov (United States)

    Martín, M. J.; Mantilla, J. M.; del Campo, D.; Hernanz, M. L.; Pons, A.; Campos, J.

    2017-09-01

    The evolving mise en pratique for the definition of the kelvin (MeP-K) [1, 2] will, in its forthcoming edition, encourage the realization and dissemination of the thermodynamic temperature either directly (primary thermometry) or indirectly (relative primary thermometry) via fixed points with assigned reference thermodynamic temperatures. In the last years, the Centro Español de Metrología (CEM), in collaboration with the Instituto de Óptica of Consejo Superior de Investigaciones Científicas (IO-CSIC), has developed several setups for absolute calibration of standard radiation thermometers using the radiance method to allow CEM the direct dissemination of the thermodynamic temperature and the assignment of the thermodynamic temperatures to several fixed points. Different calibration facilities based on a monochromator and/or a laser and an integrating sphere have been developed to calibrate CEM's standard radiation thermometers (KE-LP2 and KE-LP4) and filter radiometer (FIRA2). This system is based on the one described in [3] placed in IO-CSIC. Different light sources have been tried and tested for measuring absolute spectral radiance responsivity: a Xe-Hg 500 W lamp, a supercontinuum laser NKT SuperK-EXR20 and a diode laser emitting at 6473 nm with a typical maximum power of 120 mW. Their advantages and disadvantages have been studied such as sensitivity to interferences generated by the laser inside the filter, flux stability generated by the radiant sources and so forth. This paper describes the setups used, the uncertainty budgets and the results obtained for the absolute temperatures of Cu, Co-C, Pt-C and Re-C fixed points, measured with the three thermometers with central wavelengths around 650 nm.

  14. Radiological protection, safety and security issues in the industrial and medical applications of radiation sources

    Science.gov (United States)

    Vaz, Pedro

    2015-11-01

    The use of radiation sources, namely radioactive sealed or unsealed sources and particle accelerators and beams is ubiquitous in the industrial and medical applications of ionizing radiation. Besides radiological protection of the workers, members of the public and patients in routine situations, the use of radiation sources involves several aspects associated to the mitigation of radiological or nuclear accidents and associated emergency situations. On the other hand, during the last decade security issues became burning issues due to the potential malevolent uses of radioactive sources for the perpetration of terrorist acts using RDD (Radiological Dispersal Devices), RED (Radiation Exposure Devices) or IND (Improvised Nuclear Devices). A stringent set of international legally and non-legally binding instruments, regulations, conventions and treaties regulate nowadays the use of radioactive sources. In this paper, a review of the radiological protection issues associated to the use of radiation sources in the industrial and medical applications of ionizing radiation is performed. The associated radiation safety issues and the prevention and mitigation of incidents and accidents are discussed. A comprehensive discussion of the security issues associated to the global use of radiation sources for the aforementioned applications and the inherent radiation detection requirements will be presented. Scientific, technical, legal, ethical, socio-economic issues are put forward and discussed.

  15. ESTIMASI BEBAN PENCEMARAN POINT SOURCE DAN LIMBAH DOMESTIK DI SUNGAI KALIBARU TIMUR PROVINSI DKI JAKARTA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Rahmat Pangestu

    2017-12-01

    Full Text Available East Kalibaru River is one of the thirteen rivers flowing through Jakarta. East Kalibaru River has an important role in development of the region. Considering the increasing activities of people, settlements and number of industries along the East Kalibaru River, it is necessary to calculate contaminants load that discharged into the water body East Kalibaru. This study conducted to determine the point source and domestic waste pollution loads, using parameters of BOD, COD and TSS. The analysis showed that the total pollution loads such are calculated as 43.714 kg/day for BOD, 60.107 kg/day for COD and total 41.529 kg/day for TSS. Total pollution load discharged into river from point source effluent is amounted of 249 kg/day for BOD, 1.505 kg/day for COD and total 411 kg/day for TSS. Effect of domestic waste is very insignificant compared to the effect of point source that went into the river. The result suggest that approach that need to be done to reduce the burden of domestic waste water pollutants is by performing additional production or communal Wastewater Treatment Plant (WWTP in densely populated areas.

  16. Temporal-spatial distribution of non-point source pollution in a drinking water source reservoir watershed based on SWAT

    Directory of Open Access Journals (Sweden)

    M. Wang

    2015-05-01

    Full Text Available The conservation of drinking water source reservoirs has a close relationship between regional economic development and people’s livelihood. Research on the non-point pollution characteristics in its watershed is crucial for reservoir security. Tang Pu Reservoir watershed was selected as the study area. The non-point pollution model of Tang Pu Reservoir was established based on the SWAT (Soil and Water Assessment Tool model. The model was adjusted to analyse the temporal-spatial distribution patterns of total nitrogen (TN and total phosphorus (TP. The results showed that the loss of TN and TP in the reservoir watershed were related to precipitation in flood season. And the annual changes showed an "M" shape. It was found that the contribution of loss of TN and TP accounted for 84.5% and 85.3% in high flow years, and for 70.3% and 69.7% in low flow years, respectively. The contributions in normal flow years were 62.9% and 63.3%, respectively. The TN and TP mainly arise from Wangtan town, Gulai town, and Wangyuan town, etc. In addition, it was found that the source of TN and TP showed consistency in space.

  17. Comparative evaluation of coffee block radiation sources fabricated from 10 different instant coffees

    International Nuclear Information System (INIS)

    Kawano, Takao; Ando, Yoshiaki; Izumi, Yuuichi

    2015-01-01

    Instant coffee contains natural potassium-40 and is a very comprehensible educational tool for illustrating naturally existing radiations and radioisotopes because potassium-40 emits radiations. In the present study, a compression and formation method was applied to 10 varieties of commercially available instant coffees and 10 coffee block radiation sources were fabricated. Thus fabricated radiation sources were examined by comparing their dimensions (side length and thickness), weights and radioactivity of 40 K. For comparison, radioactivity of 40 K contained in 6 varieties of commercially available regular coffees was also measured. It was found that the dimensions and weights of the fabricated radiation sources did not significantly vary by difference of instant coffees, and the average radioactivity of 40 K contained in the 10 coffee block radiation sources was 16.6 Bq, being about 1.7 times more intensive than that of regular coffees. (author)

  18. Avoiding radiation exposure while training to locate a radioactive source: a virtual reality exercise

    International Nuclear Information System (INIS)

    Marins, E.R.; Cotelli do Espírito Santo, A.; Abreu Mól, A. C. de; Cunha, G.; Landau, L.

    2015-01-01

    A technician undergoing radioprotection training must learn to use radiation detectors. Practical exercises involve being near to radiation sources. The work here presented reduces the exposure to individuals using a virtual environment to achieve preliminary apprenticeship prior using real radioactive sources. (authors)

  19. Medical management of radiation safety and control of ionizing radiation sources in Armenia

    International Nuclear Information System (INIS)

    Hovhannisyan, N.M.

    1998-01-01

    The events of the last 10 years, Spitak earthquake (1988) and collapse of the former USSR brought forth the changes of the political situation in Armenia and significant disorder in economy, industry, relations, including the radiation safety (RS) and control of the organization of the activities connected with the ionizing radiation sources (IRSs). In 1989 the Armenian Nuclear Power Plant was shut down, and in 1994 it was restarted. In Armenia there are about 750 X-ray rooms, 10 radionuclide diagnostic laboratories, 20 gamma and X-ray units; 95 enterprises in industry, science and technology use the IRSs with different purposes, there are 5 electron particle accelerators of different power capacity. About 6,000 individuals have constant contact to IRS: the roentgenologists, radiologists, the staff of NPP, accelerators, etc. Besides, more than 3,000 liquidators of the Chernobyl NPP disaster live in Armenia. Nowadays, the precise infrastructure of RS is established in Armenia. The regulating body is the 'State Atom Authority', performing the control, coordination and licensing of both enterprises and specialists. Ministry of Health Ministry of Internal Affairs, Ministry of Ecology perform the control of IRSs' delivery into the Republic of Armenia and then their proper use and waste disposal in Armenia. (author)

  20. Radiation protection for the illegal governmental use of radiation sources. A case study

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K.

    2000-07-01

    Probably for the first time, illegal governmental uses of radiation sources, including the administrative infrastructure such as special radiation protection regulation, an advisory body etc., have been documented by the evaluation of the documents of the Ministry of State Security in the former German Democratic Republic (East Germany). Over a thousand persons, but also documents, money bills etc. were marked with a wide variety of radionuclides and traced with specially developed detectors. Among the many different nuclides provided regularly from the Rossendorf Research Center near Dresden, in particular {sup 46}Sc was popular. (orig.) [German] 'Regierungskriminalitaet' kann man auch im deutschen Strahlenschutz finden. Anhand neuer Dokumentationen der so genannten Gauckbehoerden, ueber die auch schon fluechtig in der Presse berichtet und spekuliert wurde, lassen sich Einzelheiten ueber die Vorgehensweisen einfallsreicher Stasi-Mitarbeiter, die Stasi-eigene Strahlenschutzverordnung und Strahlenschutz-Kommission usw. rekonstruieren. Ueber 1.000 Personen, aber auch Gegenstaende, Dokumente, Geldscheine etc. wurden markiert, wobei unter einer Vielzahl der regelmaessig aus Rossendorf gelieferten Nukliden {sup 46}Sc besonders gern eingesetzt sowie in Dresden spezielle Nachweisgeraete entwickelt wurden. (orig.)

  1. Aberration correction by nonlinear beam mixing: generation of a pseudo point sound source.

    Science.gov (United States)

    Seo, Jongbum; Choi, J J; Fowlkes, J Brian; O'Donnell, Matthew; Cain, Charles A

    2005-11-01

    Nonlinear beam mixing with microbubbles was explored to create a pseudo point source for aberration correction of therapeutic ultrasound. A damping coefficient for a bubble driven by a dual frequency sound field was derived by revisiting Prosperetti's linearized damping model. As a result, the overall damping term for dual frequency was obtained by linear summation of two damping terms for each frequency. The numerical simulation based on the bubble model suggests that the most efficient size range to generate a 1 MHz frequency from 4 MHz and 5 MHz sound sources is 2.6 to 3.0 microm. Furthermore, this size range constitutes the primary distribution of a specific ultrasound contrast agent. When a chamber of 0.1% of the diluted agent is sonified by 4 MHz and 5 MHz sound beams with 80 degrees incident angle between them, an approximately 100 Pa, 1 MHz difference frequency signal can be measured approximately 10 cm away. In addition, the received 1 MHz difference frequency signal shows omni-directional characteristics, even though the overlap zone of the two sound beams is on the order of the difference frequency wavelength. Therefore, the induced sound source can be considered as a pseudo point source and is expected to be useful for aberration correction for therapeutic ultrasound.

  2. [Impacts of the urbanization on waters non-point source pollution].

    Science.gov (United States)

    Yang, Liu; Ma, Ke-Ming; Guo, Qing-hai; Zhao, Jing-zhu

    2004-11-01

    Non-point source (NPS) pollution is the prominent source of water pollution in many countries, included America and China, of the world. Urban NPS pollution was attached little importance for long, compared with agriculture NPS pollution. While urbanization is the dominant form of land-use change in terms of impacts on water quality, the hydrology, other physical properties of watersheds as well as their NPS pollution potential at present. The formation of urban NPS pollution of water could be described by "source-process-sink". Urbanization has changed the source, process and sink of urban NPS pollution. A review was conducted on the international researches of urbanization impacts on NPS pollution in urban water environment from the point of view of "describe-predict and evaluation-application". The studies of urbanization impacts on urban NPS pollution were focused on modeling the process of urban NPS pollution by hydrologic model, predicting the pollutants load of NPS pollution. It is a fresh methodology that the relationship between urbanization and urban NPS pollution of water was analyzed by the method of landscape change and ecological process. The research on temporal-spatial comprehensive impacts of landscape pattern changes, led by urbanization, on the urban NPS pollution will be one of the hotspots.

  3. An Improved Statistical Point-source Foreground Model for the Epoch of Reionization

    Energy Technology Data Exchange (ETDEWEB)

    Murray, S. G.; Trott, C. M.; Jordan, C. H. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia)

    2017-08-10

    We present a sophisticated statistical point-source foreground model for low-frequency radio Epoch of Reionization (EoR) experiments using the 21 cm neutral hydrogen emission line. Motivated by our understanding of the low-frequency radio sky, we enhance the realism of two model components compared with existing models: the source count distributions as a function of flux density and spatial position (source clustering), extending current formalisms for the foreground covariance of 2D power-spectral modes in 21 cm EoR experiments. The former we generalize to an arbitrarily broken power law, and the latter to an arbitrary isotropically correlated field. This paper presents expressions for the modified covariance under these extensions, and shows that for a more realistic source spatial distribution, extra covariance arises in the EoR window that was previously unaccounted for. Failure to include this contribution can yield bias in the final power-spectrum and under-estimate uncertainties, potentially leading to a false detection of signal. The extent of this effect is uncertain, owing to ignorance of physical model parameters, but we show that it is dependent on the relative abundance of faint sources, to the effect that our extension will become more important for future deep surveys. Finally, we show that under some parameter choices, ignoring source clustering can lead to false detections on large scales, due to both the induced bias and an artificial reduction in the estimated measurement uncertainty.

  4. Radiation protection programme for LEU miniature source reactor

    International Nuclear Information System (INIS)

    Beinpuo, Ernest Sanyare Warmann

    2015-02-01

    A radiation protection program has been developed to promote radiation dose reduction. It emphasize radiological protection fundamentals geared at reducing radiation from the application of the research reactor at the reactor center of the National Nuclear Research Institute (NNRI) of the Ghana Atomic Energy Commission. The objectives of the radiation safety program are both to ensure that nuclear scientists and technicians are exposed to a minimum of ionizing radiation and to protect employees and facility users and surrounding community from any potentially harmful effects of nuclear research reactor at GAEC. The primary purpose of the radiation control program is to assure radiological safety of all personnel and the public to guarantee that ionizing radiation arising out of the operations of the Research Reactor at the Reactor Center does not adversely affect personnel, the general public or the environment. This program sets forth polices, regulations, and procedures approved by the Centers Radiation Control Committee. The regulations and procedures outlined in this program are intended to protect all individuals with a minimum of interference in their activities and are consistent with regulations of the Radiation Protection Board (RPB) applicable to ionizing radioactive producing devices. (au)

  5. Lessons Learned from OMI Observations of Point Source SO2 Pollution

    Science.gov (United States)

    Krotkov, N.; Fioletov, V.; McLinden, Chris

    2011-01-01

    The Ozone Monitoring Instrument (OMI) on NASA Aura satellite makes global daily measurements of the total column of sulfur dioxide (SO2), a short-lived trace gas produced by fossil fuel combustion, smelting, and volcanoes. Although anthropogenic SO2 signals may not be detectable in a single OMI pixel, it is possible to see the source and determine its exact location by averaging a large number of individual measurements. We describe new techniques for spatial and temporal averaging that have been applied to the OMI SO2 data to determine the spatial distributions or "fingerprints" of SO2 burdens from top 100 pollution sources in North America. The technique requires averaging of several years of OMI daily measurements to observe SO2 pollution from typical anthropogenic sources. We found that the largest point sources of SO2 in the U.S. produce elevated SO2 values over a relatively small area - within 20-30 km radius. Therefore, one needs higher than OMI spatial resolution to monitor typical SO2 sources. TROPOMI instrument on the ESA Sentinel 5 precursor mission will have improved ground resolution (approximately 7 km at nadir), but is limited to once a day measurement. A pointable geostationary UVB spectrometer with variable spatial resolution and flexible sampling frequency could potentially achieve the goal of daily monitoring of SO2 point sources and resolve downwind plumes. This concept of taking the measurements at high frequency to enhance weak signals needs to be demonstrated with a GEOCAPE precursor mission before 2020, which will help formulating GEOCAPE measurement requirements.

  6. Radiation sources in the EU. A review of steps in the European Union

    International Nuclear Information System (INIS)

    Ciani, V.

    1999-01-01

    This article reviews the role and activities of the European Union concerning safety of radiation sources. A brief presentation is given of the results from a recent study of the management of radiation sources in EU Member Sates. A Number of legal texts which apply to radiation sources are cited as well. In 1998, the EC co-sponsored together with the IAEA, the International Criminal Police Organization and the World Customs Organization, a Conference on the safety of radiation Sources and the Security of Radioactive Materials in France. Commission supports follow-up actions to that Conference and welcomes the IAEA initiative to develop an action plan that would address the international dimensions of the safety of radiation sources

  7. Electronic equilibrium as a function of depth in tissue from cobalt-60 point source exposures

    International Nuclear Information System (INIS)

    Myrick, J.A.

    1994-08-01

    The Nuclear Regulatory Commission has set the basic criteria for assessing skin dose stemming from hot particle contaminations. Compliance with 10 CFR 20.101 requires that exposure to the skin be evaluated over a 1 cm 2 area at a depth of 0.007 cm. Skin exposure can arise from both the beta and gamma components of radioactive particles and gamma radiation can contribute significantly to skin doses. The gamma component of dose increases dramatically when layers of protective clothing are interposed between the hot particle source and the skin, and in cases where the hot particle is large in comparison to the range of beta particles. Once the protective clothing layer is thicker than the maximum range of the beta particles, skin dose is due solely to gamma radiation. Charged particle equilibrium is not established at shallow depths. The degree of electronic equilibrium establishment must be assessed for shallow doses to prevent the over-assessment of skin dose because conventional fluence-to-dose conversion factors are not applicable. To assess the effect of electronic equilibrium, selected thicknesses of tissue equivalent material were interposed between radiochromic dye film and a 60 Co hot particle source and dose was measured as a function of depth. These measured values were then compared to models which are used to calculate charged particle equilibrium. The Miller-Reece model was found to agree closely with the experimental data while the Lantz-Lambert model overestimated dose at shallow depths

  8. Synchrotron radiation sources: their properties and applications for VUV and X-ray spectroscopy

    International Nuclear Information System (INIS)

    Koch, E.E.

    1976-09-01

    Synchrotron radiation from accelerators and storage rings offers far reaching possibilities for many fields of basic and applied physics. The properties of synchrotron radiation, existing and planned synchrotron radiation facilities, as well as instrumental aspects are discussed. In order to illustrate the usefulness of the synchrotron radiation sources a few highlights from atomic, molelucar, and solid state spectroscopy are presented and examples from x-ray experiments and from the field of applied physics are given. (orig.) [de

  9. Diffusion of dust particles from a point-source above ground level

    International Nuclear Information System (INIS)

    Hassan, M.H.A.; Eltayeb, I.A.

    1998-10-01

    A pollutant of small particles is emitted by a point source at a height h above ground level in an atmosphere in which a uni-directional wind speed, U, is prevailing. The pollutant is subjected to diffusion in all directions in the presence of advection and settling due to gravity. The equation governing the concentration of the pollutant is studied with the wind speed and the different components of diffusion tensor are proportional to the distance above ground level and the source has a uniform strength. Adopting a Cartesian system of coordinates in which the x-axis lies along the direction of the wind velocity, the z-axis is vertically upwards and the y-axis completes the right-hand triad, the solution for the concentration c(x,y,z) is obtained in closed form. The relative importance of the components of diffusion along the three axes is discussed. It is found that for any plane y=constant (=A), c(x,y,z) is concentrated along a curve of ''extensive pollution''. In the plane A=0, the concentration decreases along the line of extensive pollution as we move away from the source. However, for planes A≅0, the line of extensive pollution possesses a point of accumulation, which lies at a nonzero value of x. As we move away from the plane A=0, the point of accumulation moves laterally away from the plane x=0 and towards the plane z=0. The presence of the point of accumulation is entirely due to the presence of lateral diffusion. (author)

  10. A new source of radiation in single-bubble sonoluminescence

    Indian Academy of Sciences (India)

    2017-03-28

    Mar 28, 2017 ... In this article, by considering single-bubble sonoluminescence and based on the hydrochemical model and thermal bremsstrahlung approach, for the first time two different origins of light have numerically been studied to describe the Ar bubble radiation in water at the moment of collapse: (a) radiation.

  11. Management of ionizing radiation sources in university, medical and industrial environments

    International Nuclear Information System (INIS)

    2000-01-01

    This conference treats several subjects relative to the use of radioactive sources. The first session comprises three articles about ionizing sources and regulation. The second session, with three articles, tackles the question of radiation protection in the use of sources in industrial field. The third session, four articles, treats the same question but in the medicine and university media. The fourth session (three articles) is devoted to the organisation of radiation protection in the case of accidents. The fifth session concerns the management of spent sources (three articles). The sixth session studies the radiation protection of sources in Europe. The seventh and final session ends with the part and coordination of actors in radiation protection in the sources management (three articles). (N.C.)

  12. Wave field synthesis of moving virtual sound sources with complex radiation properties.

    Science.gov (United States)

    Ahrens, Jens; Spors, Sascha

    2011-11-01

    An approach to the synthesis of moving virtual sound sources with complex radiation properties in wave field synthesis is presented. The approach exploits the fact that any stationary sound source of finite spatial extent radiates spherical waves at sufficient distance. The angular dependency of the radiation properties of the source under consideration is reflected by the amplitude and phase distribution on the spherical wave fronts. The sound field emitted by a uniformly moving monopole source is derived and the far-field radiation properties of the complex virtual source under consideration are incorporated in order to derive a closed-form expression for the loudspeaker driving signal. The results are illustrated via numerical simulations of the synthesis of the sound field of a sample moving complex virtual source.

  13. Reprint of Inexact Bregman iteration for deconvolution of superimposed extended and point sources

    Science.gov (United States)

    Benfenati, A.; Ruggiero, V.

    2015-04-01

    In this paper we consider the deconvolution of high contrast images consisting of very bright stars (point component) and smooth structures underlying the stars (diffuse component). A typical case is a weak diffuse jet line emission superimposed to a strong stellar continuum. In order to reconstruct the diffuse component, the original object can be regarded as the sum of these two components. When the position of the point sources is known, a regularization term can be introduced for the second component. An approximation of the original object can be obtained by solving a reduced variational problem whose unknowns are the intensities of the stars and the diffuse component. We analyze this problem when the detected image is corrupted by Poisson noise and Tikhonov-like regularization is used, giving conditions for the existence and the uniqueness of the solution. Furthermore, since only an overestimation of the regularization parameter is available, we propose to solve the variational problem by inexact Bregman iteration combined with a Scaled Gradient Projection method (SGP). Numerical simulations show that the images obtained with this approach enable us to reconstruct the original intensity distribution around the point source with satisfactory accuracy.

  14. Inexact Bregman iteration for deconvolution of superimposed extended and point sources

    Science.gov (United States)

    Benfenati, A.; Ruggiero, V.

    2015-03-01

    In this paper we consider the deconvolution of high contrast images consisting of very bright stars (point component) and smooth structures underlying the stars (diffuse component). A typical case is a weak diffuse jet line emission superimposed to a strong stellar continuum. In order to reconstruct the diffuse component, the original object can be regarded as the sum of these two components. When the position of the point sources is known, a regularization term can be introduced for the second component. An approximation of the original object can be obtained by solving a reduced variational problem whose unknowns are the intensities of the stars and the diffuse component. We analyze this problem when the detected image is corrupted by Poisson noise and Tikhonov-like regularization is used, giving conditions for the existence and the uniqueness of the solution. Furthermore, since only an overestimation of the regularization parameter is available, we propose to solve the variational problem by inexact Bregman iteration combined with a Scaled Gradient Projection method (SGP). Numerical simulations show that the images obtained with this approach enable us to reconstruct the original intensity distribution around the point source with satisfactory accuracy.

  15. AN IN-DEPTH VIEW OF THE MID-INFRARED PROPERTIES OF POINT SOURCES AND THE DIFFUSE ISM IN THE SMC GIANT H II REGION, N66

    International Nuclear Information System (INIS)

    Whelan, David G.; Johnson, Kelsey E.; Indebetouw, Rémy; Lebouteiller, Vianney; Galliano, Frédéric; Peeters, Els; Bernard-Salas, Jeronimo; Brandl, Bernhard R.

    2013-01-01

    The focus of this work is to study mid-infrared point sources and the diffuse interstellar medium (ISM) in the low-metallicity (∼0.2 Z ☉ ) giant H II region N66 in order to determine properties that may shed light on star formation in these conditions. Using the Spitzer Space Telescope's Infrared Spectrograph, we study polycyclic aromatic hydrocarbon (PAH), dust continuum, silicate, and ionic line emission from 14 targeted infrared point sources as well as spectra of the diffuse ISM that is representative of both the photodissociation regions (PDRs) and the H II regions. Among the point source spectra, we spectroscopically confirm that the brightest mid-infrared point source is a massive embedded young stellar object, we detect silicates in emission associated with two young stellar clusters, and we see spectral features of a known B[e] star that are commonly associated with Herbig Be stars. In the diffuse ISM, we provide additional evidence that the very small grain population is being photodestroyed in the hard radiation field. The 11.3 μm PAH complex emission exhibits an unexplained centroid shift in both the point source and ISM spectra that should be investigated at higher signal-to-noise and resolution. Unlike studies of other regions, the 6.2 μm and 7.7 μm band fluxes are decoupled; the data points cover a large range of I 7.7 /I 11.3 PAH ratio values within a narrow band of I 6.2 /I 11.3 ratio values. Furthermore, there is a spread in PAH ionization, being more neutral in the dense PDR where the radiation field is relatively soft, but ionized in the diffuse ISM/PDR. By contrast, the PAH size distribution appears to be independent of local ionization state. Important to unresolved studies of extragalactic low-metallicity star-forming regions, we find that emission from the infrared-bright point sources accounts for only 20%-35% of the PAH emission from the entire region. These results make a comparative data set to other star-forming regions with

  16. Mercury exposure in terrestrial birds far downstream of an historical point source

    International Nuclear Information System (INIS)

    Jackson, Allyson K.; Evers, David C.; Folsom, Sarah B.; Condon, Anne M.; Diener, John; Goodrick, Lizzie F.; McGann, Andrew J.; Schmerfeld, John; Cristol, Daniel A.

    2011-01-01

    Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: → We report blood mercury levels for terrestrial songbirds downstream of contamination. → Blood mercury levels remain elevated above reference for at least 137 km downstream. → Trends vary based on foraging guild and migration strategy. → Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

  17. Point source detection performance of Hard X-ray Modulation Telescope imaging observation

    International Nuclear Information System (INIS)

    Huo, Zhuo-Xi; Li, Yi-Ming; Li, Xiao-Bo; Zhou, Jian-Feng

    2015-01-01

    The Hard X-ray Modulation Telescope (HXMT) will perform an all-sky survey in the hard X-ray band as well as deep imaging of a series of small sky regions. We expect various compact objects to be detected in these imaging observations. Point source detection performance of HXMT imaging observation depends not only on the instrument but also on the data analysis method that is applied since images are reconstructed from HXMT observed data with numerical methods. The denoising technique used plays an important part in the HXMT imaging data analysis pipeline along with demodulation and source detection. In this paper we have implemented several methods for denoising HXMT data and evaluated the point source detection performances in terms of sensitivities and location accuracies. The results show that direct demodulation with 1-fold cross-correlation should be the default reconstruction and regularization method, although both sensitivity and location accuracy could be further improved by selecting and tuning numerical methods in data analysis used for HXMT imaging observations. (paper)

  18. Shielding NSLS-II light source: Importance of geometry for calculating radiation levels from beam losses

    Science.gov (United States)

    Kramer, S. L.; Ghosh, V. J.; Breitfeller, M.; Wahl, W.

    2016-11-01

    Third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produces significantly higher neutron component dose to the experimental floor than a lower energy beam injection and ramped operations. Minimizing this dose will require adequate knowledge of where the miss-steered beam can occur and sufficient EM shielding close to the loss point, in order to attenuate the energy of the particles in the EM shower below the neutron production threshold (Designing supplemental shielding near the loss point using the analytic shielding model is shown to be inadequate because of its lack of geometry specification for the EM shower process. To predict the dose rates outside the tunnel requires detailed description of the geometry and materials that the beam losses will encounter inside the tunnel. Modern radiation shielding Monte-Carlo codes, like FLUKA, can handle this geometric description of the radiation transport process in sufficient detail, allowing accurate predictions of the dose rates expected and the ability to show weaknesses in the design before a high radiation incident occurs. The effort required to adequately define the accelerator geometry for these codes has been greatly reduced with the implementation of the graphical interface of FLAIR to FLUKA. This made the effective shielding process for NSLS-II quite accurate and reliable. The principles used to provide supplemental shielding to the NSLS-II accelerators and the lessons learned from this process are presented.

  19. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. I. POINT-SOURCE CATALOG

    International Nuclear Information System (INIS)

    Kato, Daisuke; Onaka, Takashi; Shimonishi, Takashi; Sakon, Itsuki; Ita, Yoshifusa; Tanabé, Toshihiko; Takahashi, Hidenori; Kaneda, Hidehiro; Kawamura, Akiko; Wada, Takehiko; Usui, Fumihiko; Koo, Bon-Chul; Matsuura, Mikako

    2012-01-01

    We present a near- to mid-infrared point-source catalog of five photometric bands at 3.2, 7, 11, 15, and 24 μm for a 10 deg 2 area of the Large Magellanic Cloud (LMC) obtained with the Infrared Camera on board the AKARI satellite. To cover the survey area the observations were carried out at three separate seasons from 2006 May to June, 2006 October to December, and 2007 March to July. The 10σ limiting magnitudes of the present survey are 17.9, 13.8, 12.4, 9.9, and 8.6 mag at 3.2, 7, 11, 15, and 24 μm, respectively. The photometric accuracy is estimated to be about 0.1 mag at 3.2 μm and 0.06-0.07 mag in the other bands. The position accuracy is 0.''3 at 3.2, 7, and 11 μm and 1.''0 at 15 and 24 μm. The sensitivities at 3.2, 7, and 24 μm are roughly comparable to those of the Spitzer SAGE LMC point-source catalog, while the AKARI catalog provides the data at 11 and 15 μm, covering the mid-infrared spectral range contiguously. Two types of catalog are provided: a Catalog and an Archive. The Archive contains all the detected sources, while the Catalog only includes the sources that have a counterpart in the Spitzer SAGE point-source catalog. The Archive contains about 650,000, 140,000, 97,000, 43,000, and 52,000 sources at 3.2, 7, 11, 15, and 24 μm, respectively. Based on the catalog, we discuss the luminosity functions at each band, the color-color diagram, and the color-magnitude diagram using the 3.2, 7, and 11 μm band data. Stars without circumstellar envelopes, dusty C-rich and O-rich stars, young stellar objects, and background galaxies are located at distinct regions in the diagrams, suggesting that the present catalog is useful for the classification of objects toward the LMC.

  20. Ionizing radiation sources management in the Commonwealth of Independent States - CIS

    International Nuclear Information System (INIS)

    Iskra, A.; Bufetova, M.

    2006-01-01

    Ionizing radiation sources cover a broad band of power: from powerful NPP reactors and research reactors to portable radioisotope ionizing radiation sources applied in medicine, agriculture, industry and in the energy supply systems of remote facilities. At present, scales and use field of radionuclide sources in the CIS have the tendency to increase. In this connection, the issues of ionizing radiation sources management safety at all stages of their life cycle, from production to treatment, have been of a great importance. The materials on ionizing radiation sources inventory and treatment in the CIS (Russia, Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan and Ukraine) are presented in the report. It is shown that in some republics, there is difficulty in ionizing radiation sources accounting and control system; the national regulatory and legal framework bases regulating activity on radioactive sources use, localization and treatment require update. Many problems are connected with the sources beyond state accounting. The problem of ionizing radiation sources use safety is complicated by the growing activity of various terrorist groups. The opportunity to use ionizing radiation sources with terrorism goals requires the application of defined systems of security and physical protection at all stages of their management. For this purpose a collective, with all CIS countries, organization of radioactive sources accounting and control as well as countermeasures on their illegal transportation and use are necessary. In this connection, the information collection regarding situation with providing of ionizing radiation sources safety, conditions of equipment and storage facilities, radioactive materials accounting and control system in the CIS countries is vitally needed

  1. Development of quality assurance procedures for production of sealed radiation source

    International Nuclear Information System (INIS)

    Nam, J. H.; Han, H. S.; Cho, W. K.; Kim, S. D.; Hong, S. B.; Chang, K. D.; Lim, N. J.; Lee, Y. G.; Kim, K. H.

    2001-11-01

    The quality assurance procedures for sealed radiation sources production using HANARO and RIPF have been developed. The detailed quality assurance procedures are essential to manage the whole work process effectively and ensure the quality of the produced sealed sources. Through applying this quality assurance procedures to the entire production works of the sealed radiation sources, it is expected that the quality of the products, the safety of the works and the satisfaction of the customers will be increased

  2. Development of quality assurance procedures for production of sealed radiation source

    CERN Document Server

    Nam, J H; Cho, W K; Han, H S; Hong, S B; Kim, K H; Kim, S D; Lee, Y G; Lim, N J

    2001-01-01

    The quality assurance procedures for sealed radiation sources production using HANARO and RIPF have been developed. The detailed quality assurance procedures are essential to manage the whole work process effectively and ensure the quality of the produced sealed sources. Through applying this quality assurance procedures to the entire production works of the sealed radiation sources, it is expected that the quality of the products, the safety of the works and the satisfaction of the customers will be increased.

  3. The high pressure xenon lamp as a source of radiation

    International Nuclear Information System (INIS)

    Heerdt, J.A. ter.

    1979-01-01

    An account is given of an investigation into the radiation properties of a commercially available high pressure xenon lamp (type XBO 900 W) in the spectral range 0.3 to 3 μm. The purpose of the study was to find out whether such a lamp can serve as a (secondary) standard of radiation in spectroscopic and radiometric measurements. The main advantades of the xenon lamp over other secondary standards such as the tungsten strip lamp and the anode of a carbon arc lamp are the high temperature of its discharge and the resulting strong radiation over a broad spectral range. (Auth.)

  4. Mixing of a point-source indoor pollutant: Numerical predictions and comparison with experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lobscheid, C.; Gadgil, A.J.

    2002-01-01

    In most practical estimates of indoor pollutant exposures, it is common to assume that the pollutant is uniformly and instantaneously mixed in the indoor space. It is also commonly known that this assumption is simplistic, particularly for point sources, and for short-term or localized indoor exposures. We report computational fluid dynamics (CFD) predictions of mixing time of a point-pulse release of a pollutant in an unventilated mechanically mixed isothermal room. We aimed to determine the adequacy of the standard RANS two-equation ({kappa}-{var_epsilon}) turbulence model to predict the mixing times under these conditions. The predictions were made for the twelve mixing time experiments performed by Drescher et al. (1995). We paid attention to adequate grid resolution, suppression of numerical diffusion, and careful simulation of the mechanical blowers used in the experiments. We found that the predictions are in good agreement with experimental measurements.

  5. A systematic analysis of the Braitenberg vehicle 2b for point-like stimulus sources

    International Nuclear Information System (INIS)

    Rañó, Iñaki

    2012-01-01

    Braitenberg vehicles have been used experimentally for decades in robotics with limited empirical understanding. This paper presents the first mathematical model of the vehicle 2b, displaying so-called aggression behaviour, and analyses the possible trajectories for point-like smooth stimulus sources. This sensory-motor steering control mechanism is used to implement biologically grounded target approach, target-seeking or obstacle-avoidance behaviour. However, the analysis of the resulting model reveals that complex and unexpected trajectories can result even for point-like stimuli. We also prove how the implementation of the controller and the vehicle morphology interact to affect the behaviour of the vehicle. This work provides a better understanding of Braitenberg vehicle 2b, explains experimental results and paves the way for a formally grounded application on robotics as well as for a new way of understanding target seeking in biology. (paper)

  6. Potential radiation exposure in emergencies involving neutron sources

    International Nuclear Information System (INIS)

    Marathe, P.K.; Bisht, J.S.; Massand, O.P.; Venkataraman, G.; Nandakumar, A.N.

    1996-01-01

    Incidents involving neutron sources, particularly in the field of oil well logging, may involve potential hazards by way of source lost above ground, lost under water at a depth or source damaged and spread over an area. While every effort should be made for retrieving a lost source or contain the contamination, there could be occasions when abandonment of the source may be preferable to retrieval. However, the decision to abandon the source needs to be guided primarily by considerations of potential exposure and the cost of retrieval. This report briefly discusses these aspects of such emergencies. 5 refs., 3 figs., 3 tabs

  7. Preliminary data summary for the pulp, paper and paperboard point source category

    Energy Technology Data Exchange (ETDEWEB)

    1989-08-01

    The Preliminary Data Summary for the Pulp, Paper and Paperboard Point Source category is a collection of four documents: (1) Overview of the United States Pulp, Paper and Paperboard Industry and Production Processes (October 1987); (2) U.S. EPA/Paper Industry Cooperative Dioxin Screening Study (March 1988); (3) Statement of Martha G. Prothro, Director, Office of Water Regulations and Standards, before the Subcommittee on Water Resources of the Committee on Public Works and Transportation, U.S. House of Representatives (July 13, 1988); (4) U.S. EPA/Paper Industry Cooperative Dioxin Study, Analytical Results (June 16, 1989).

  8. A method for untriggered time-dependent searches for multiple flares from neutrino point sources

    International Nuclear Information System (INIS)

    Gora, D.; Bernardini, E.; Cruz Silva, A.H.

    2011-04-01

    A method for a time-dependent search for flaring astrophysical sources which can be potentially detected by large neutrino experiments is presented. The method uses a time-clustering algorithm combined with an unbinned likelihood procedure. By including in the likelihood function a signal term which describes the contribution of many small clusters of signal-like events, this method provides an effective way for looking for weak neutrino flares over different time-scales. The method is sensitive to an overall excess of events distributed over several flares which are not individually detectable. For standard cases (one flare) the discovery potential of the method is worse than a standard time-dependent point source analysis with unknown duration of the flare by a factor depending on the signal-to-background level. However, for flares sufficiently shorter than the total observation period, the method is more sensitive than a time-integrated analysis. (orig.)

  9. A method for untriggered time-dependent searches for multiple flares from neutrino point sources

    Energy Technology Data Exchange (ETDEWEB)

    Gora, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institute of Nuclear Physics PAN, Cracow (Poland); Bernardini, E.; Cruz Silva, A.H. [Institute of Nuclear Physics PAN, Cracow (Poland)

    2011-04-15

    A method for a time-dependent search for flaring astrophysical sources which can be potentially detected by large neutrino experiments is presented. The method uses a time-clustering algorithm combined with an unbinned likelihood procedure. By including in the likelihood function a signal term which describes the contribution of many small clusters of signal-like events, this method provides an effective way for looking for weak neutrino flares over different time-scales. The method is sensitive to an overall excess of events distributed over several flares which are not individually detectable. For standard cases (one flare) the discovery potential of the method is worse than a standard time-dependent point source analysis with unknown duration of the flare by a factor depending on the signal-to-background level. However, for flares sufficiently shorter than the total observation period, the method is more sensitive than a time-integrated analysis. (orig.)

  10. Development of uniform hazard response spectra for rock sites considering line and point sources of earthquakes

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Kushwaha, H.S.

    2001-12-01

    Traditionally, the seismic design basis ground motion has been specified by normalised response spectral shapes and peak ground acceleration (PGA). The mean recurrence interval (MRI) used to computed for PGA only. It is shown that the MRI associated with such response spectra are not the same at all frequencies. The present work develops uniform hazard response spectra i.e. spectra having the same MRI at all frequencies for line and point sources of earthquakes by using a large number of strong motion accelerograms recorded on rock sites. Sensitivity of the number of the results to the changes in various parameters has also been presented. This work is an extension of an earlier work for aerial sources of earthquakes. These results will help to determine the seismic hazard at a given site and the associated uncertainities. (author)

  11. Decreasing Computational Time for VBBinaryLensing by Point Source Approximation

    Science.gov (United States)

    Tirrell, Bethany M.; Visgaitis, Tiffany A.; Bozza, Valerio

    2018-01-01

    The gravitational lens of a binary system produces a magnification map that is more intricate than a single object lens. This map cannot be calculated analytically and one must rely on computational methods to resolve. There are generally two methods of computing the microlensed flux of a source. One is based on ray-shooting maps (Kayser, Refsdal, & Stabell 1986), while the other method is based on an application of Green’s theorem. This second method finds the area of an image by calculating a Riemann integral along the image contour. VBBinaryLensing is a C++ contour integration code developed by Valerio Bozza, which utilizes this method. The parameters at which the source object could be treated as a point source, or in other words, when the source is far enough from the caustic, was of interest to substantially decrease the computational time. The maximum and minimum values of the caustic curves produced, were examined to determine the boundaries for which this simplification could be made. The code was then run for a number of different maps, with separation values and accuracies ranging from 10-1 to 10-3, to test the theoretical model and determine a safe buffer for which minimal error could be made for the approximation. The determined buffer was 1.5+5q, with q being the mass ratio. The theoretical model and the calculated points worked for all combinations of the separation values and different accuracies except the map with accuracy and separation equal to 10-3 for y1 max. An alternative approach has to be found in order to accommodate a wider range of parameters.

  12. Semi analytical solution of point kinetic equation with source from cold start up to delayed critical

    International Nuclear Information System (INIS)

    Sathiyasheela, T.

    2009-01-01

    Point kinetics equations (P. K. E) are system of differential equations, which is solved simultaneously to get the neutron density as a function of time for a given reactivity input. P. K. E are stiff differential equations, computational solution through the conventional explicit method will give a stable consistent result only for smaller time steps. Analytical solutions are available either with step or ramp reactivity insertion without considering the source power contribution. When a reactor operates at low power, the neutron source gives a considerable contribution to the net reactor power. Similarly, when the reactor is brought to delayed critical with the presence of external source, the sub critical reactor kinetics studies with source power are important to understand the power behavior as a function of reactivity insertion rate with respect to the initial reactivity. In the present work, P.K.E with one group delayed neutron are solved analytically to determine the reactor power as a function of reactivity insertion rate in the presence of neutron source. The analytical solution is a combination of converging two infinite series. Truncated infinite series is the analytical solution of P.K E. A general formulation is made by Combining both the ramp reactivity and step reactivity solution. So that the analytical solution could be useful in analyzing either step and ramp reactivity insertion exclusively or the combination of both. This general formulation could be useful in analyzing many reactor operations, like the air bubble passing through the core, stuck rod conditions, uncontrolled withdrawal of controlled rod, discontinuous lifting of control rod, lowering of rod and etc. Results of analytical solutions are compared against the results of numerical solution which is developed based on Cohen's method. The comparisons are found to be good for all kind of positive and negative ramp reactivity insertions, with or without the combination of step reactivity

  13. Neon dense plasma focus point x-ray source for <= 0.25 um lithography

    Science.gov (United States)

    Prasad, Rahul R.; Krishnan, Mahadevan; Mangano, Joseph; Greene, Philip A.; Qi, Niansheng

    1994-05-01

    A discharge driven, dense plasma focus (DPF) in Neon has been developed at SRL as a point x-ray source for sub-micron lithography. This source is presently capable of delivering approximately 25 J/pulse of Neon K-shell x rays (8 - 14 angstrom) into 4 (pi) steradians with an approximately equals 1.4% wall plug efficiency at a 20 Hz repetition rate. This corresponds to 500 W of average x-ray power. The discharge is produced by a capacitor bank circuit (8 kV, 1.8 kJ) that drives approximately equals 320 kA currents into the DPF load, with approximately equals 1 microsecond(s) rise-times. X rays are produced when a dense pinch of Neon is formed along the axis of the DPF electrodes. Four X ten5 discharges using a cooled DPF head have been fired producing x rays. The variation in the measured x-ray output, over several 104 shots, corresponds to a variation in the dose delivered to a resist 40 cm from the source, of less than 1%. Data showing the measurement of the x-ray output, size, dose delivered to a resist, spectra of the source output, novel beam line concepts, and potential lithographic applications are discussed.

  14. Point, surface and volumetric heat sources in the thermal modelling of selective laser melting

    Science.gov (United States)

    Yang, Yabin; Ayas, Can

    2017-10-01

    Selective laser melting (SLM) is a powder based additive manufacturing technique suitable for producing high precision metal parts. However, distortions and residual stresses within products arise during SLM because of the high temperature gradients created by the laser heating. Residual stresses limit the load resistance of the product and may even lead to fracture during the built process. It is therefore of paramount importance to predict the level of part distortion and residual stress as a function of SLM process parameters which requires a reliable thermal modelling of the SLM process. Consequently, a key question arises which is how to describe the laser source appropriately. Reasonable simplification of the laser representation is crucial for the computational efficiency of the thermal model of the SLM process. In this paper, first a semi-analytical thermal modelling approach is described. Subsequently, the laser heating is modelled using point, surface and volumetric sources, in order to compare the influence of different laser source geometries on the thermal history prediction of the thermal model. The present work provides guidelines on appropriate representation of the laser source in the thermal modelling of the SLM process.

  15. Co-C and Pd-C Eutectic Fixed Points for Radiation Thermometry and Thermocouple Thermometry

    Science.gov (United States)

    Wang, L.

    2017-12-01

    Two Co-C and Pd-C eutectic fixed point cells for both radiation thermometry and thermocouple thermometry were constructed at NMC. This paper describes details of the cell design, materials used, and fabrication of the cells. The melting curves of the Co-C and Pd-C cells were measured with a reference radiation thermometer realized in both a single-zone furnace and a three-zone furnace in order to investigate furnace effect. The transition temperatures in terms of ITS-90 were determined to be 1324.18 {°}C and 1491.61 {°}C with the corresponding combined standard uncertainty of 0.44 {°}C and 0.31 {°}C for Co-C and Pd-C, respectively, taking into account of the differences of two different types of furnaces used. The determined ITS-90 temperatures are also compared with that of INRIM cells obtained using the same reference radiation thermometer and the same furnaces with the same settings during a previous bilateral comparison exercise (Battuello et al. in Int J Thermophys 35:535-546, 2014). The agreements are within k=1 uncertainty for Co-C cell and k = 2 uncertainty for Pd-C cell. Shapes of the plateaus of NMC cells and INRIM cells are compared too and furnace effects are analyzed as well. The melting curves of the Co-C and Pd-C cells realized in the single-zone furnace are also measured by a Pt/Pd thermocouple, and the preliminary results are presented as well.

  16. Multi-Point Measurements to Characterize Radiation Belt Electron Precipitation Loss

    Science.gov (United States)

    Blum, L. W.

    2017-12-01

    Multipoint measurements in the inner magnetosphere allow the spatial and temporal evolution of various particle populations and wave modes to be disentangled. To better characterize and quantify radiation belt precipitation loss, we utilize multi-point measurements both to study precipitating electrons directly as well as the potential drivers of this loss process. Magnetically conjugate CubeSat and balloon measurements are combined to estimate of the temporal and spatial characteristics of dusk-side precipitation features and quantify loss due to these events. To then understand the drivers of precipitation events, and what determines their spatial structure, we utilize measurements from the dual Van Allen Probes to estimate spatial and temporal scales of various wave modes in the inner magnetosphere, and compare these to precipitation characteristics. The structure, timing, and spatial extent of waves are compared to those of MeV electron precipitation during a few individual events to determine when and where EMIC waves cause radiation belt electron precipitation. Magnetically conjugate measurements provide observational support of the theoretical picture of duskside interaction of EMIC waves and MeV electrons leading to radiation belt loss. Finally, understanding the drivers controlling the spatial scales of wave activity in the inner magnetosphere is critical for uncovering the underlying physics behind the wave generation as well as for better predicting where and when waves will be present. Again using multipoint measurements from the Van Allen Probes, we estimate the spatial and temporal extents and evolution of plasma structures and their gradients in the inner magnetosphere, to better understand the drivers of magnetospheric wave characteristic scales. In particular, we focus on EMIC waves and the plasma parameters important for their growth, namely cold plasma density and cool and warm ion density, anisotropy, and composition.

  17. Off-axis viewing of radiation emission by long wiggler sources

    International Nuclear Information System (INIS)

    Berman, L.; Yin, Z.

    2011-01-01

    When high-brilliance radiation is needed for experiments, insertion device sources are generally viewed on-axis. Off-axis emission of flux can be prodigious especially from wiggler sources having large emission fans. The on-axis and off-axis radiation emission characteristics from insertion device sources have been calculated extensively and are well known, but experimental verifications of some characteristics, particularly those associated with off-axis emission, are relatively few. Here measurements of the flux spectrum and apparent source size are described, as a function of horizontal emission angle, from the former X25 hybrid wiggler at the National Synchrotron Light Source (NSLS).

  18. Loss and recovery of radiation sources in India

    International Nuclear Information System (INIS)

    Mishra, U.C.; Pradhan, A.S.

    1998-01-01

    Loss of radioisotope sources occurs as a result of the violation of safe work practices and non-compliance with rules and guidelines. The main causes are human error, negligence in source handling and storage as well as mismanagement and lack of supervision. The failure to adequately supervise and manage leads to a breakdown in communication and differences among workers, supervisors and managers. Recovery of lost sources is generally a tedious task. In India, apart from the efforts of the user institution, a team of scientists from the Bhabha Atomic Research Centre (BARC) undertakes searches and supervises recovery operations. Sources have been lost in brachytherapy and nuclear medicine departments of hospitals and in industrial institutions. For brachytherapy source losses, hospital garbage, dustbins, passages and lifts were the main targets for searches. While gamma ray and neutron sources could be traced for the most part, pure beta ray sources, such as Sr-90 used in ophthalmic applicators or as check sources, could not be recovered. In industrial radiography, the search for sources was more problematic, especially when the sources were stolen or lost in transport. Lost materials could not be traced in only two out of eleven instances of loss of Ir-192 sources since 1986. In a separate incident, sources which had been stolen were found in a deep river: this necessitated an elaborate fishing operation at a cost of some US$100,000. Each occurrence provided lessons calling for the introduction of new control measures. (author)

  19. A new algorithm for accurate and fast evaluation of the Hubbell radiation rectangular source function

    International Nuclear Information System (INIS)

    Mamedov, B. A.; Ekenoglu, A. S.; Askerov, I. M.

    2006-01-01

    The Hubbell radiation rectangular source (HRS) function plays an important role in the evaluation of the radiation field generated by a plane isotropic rectangular source (plaque). In this work we present a new efficient and reliable analytical procedure for evaluation of the Hubbell radiation rectangular source (HRS) integral using a binomial expansion. The proposed procedure guarantees the reliable evaluation of the radiation field generated by a plane isotropic rectangular source (plaque) of scaled width and length a and b. The formulas obtained are numerically stable for a + b 2 <1. The quantities a=w/h and b=l/h are defined in the range 0< a≤b≤∞. Here h is the height over a corner of a plane isotropic rectangular (plaque) source of length l and width w. Numerical results are presented and compared with results using alternative evaluation schemes

  20. Radiation source reconstruction with known geometry and materials using the adjoint

    International Nuclear Information System (INIS)

    Hykes, Joshua M.; Azmy, Yousry Y.

    2011-01-01

    We present a method to estimate an unknown isotropic source distribution, in space and energy, using detector measurements when the geometry and material composition are known. The estimated source distribution minimizes the difference between the measured and computed responses of detectors located at a selected number of points within the domain. In typical methods, a forward flux calculation is performed for each source guess in an iterative process. In contrast, we use the adjoint flux to compute the responses. Potential applications of the proposed method include determining the distribution of radio-contaminants following a nuclear event, monitoring the flow of radioactive fluids in pipes to determine hold-up locations, and retroactive reconstruction of radiation fields using workers' detectors' readings. After presenting the method, we describe a numerical test problem to demonstrate the preliminary viability of the method. As expected, using the adjoint flux reduces the number of transport solves to be proportional to the number of detector measurements, in contrast to methods using the forward flux that require a typically larger number proportional to the number of spatial mesh cells. (author)

  1. The role of radiation therapy in the multidisciplinary treatment of patients with malignant tumors. Radiation pathological stand point

    International Nuclear Information System (INIS)

    Niibe, Hideo

    1998-01-01

    Estimations suggest that about 60% of all cancer patients will require some form of radiation therapy during their lifetime. Although 40 to 50% of cancer patients in Europe and the United States receive radiation therapy, only about 20% of patients with cancer in Japan undergo such treatment. This is largely due to the lack of understanding of the role of radiation therapy by many medical personnel in Japan, as well as to ''''radiation allergy'''' among many of the general population in Japan, a country that has been undergone atomic bombing. From our perspective as specialists in radiation therapy, the chronic shortage of radiation oncologist also poses a serious problem. Although there are approximately 700 hospitals throughout Japan where radiation therapy is available, no more than half this number of medical facilities have a full-time radiation oncologist. Perhaps the reason for this is that radiation therapy is perceived as unnecessary in Japan. However, it is absolutely essential. In our experience, the 5-year relative survival rate of patients with malignant tumors who have undergone radiation therapy in our clinic is 65 percent. Thus, radiation therapy has proven very useful in the treatment of malignant tumors. Moreover, better estimates of prognosis of cancer patients treated with radiation therapy are becoming possible. This article discusses the role of radiation therapy, from a radiation pathological perspective, in a multidisciplinary approach to treatment of cancer patients. I also emphasize the critical importance of training radiation oncologists who can function as part of multidisciplinary teams that care for patients with malignant tumors. (author). 50 refs

  2. Current status of control of radiation sources and radioactive materials in the United Republic of Tanzania

    International Nuclear Information System (INIS)

    Nyaruba, M.M.; Mompome, W.K.

    2001-01-01

    A Protection from Radiation Act was enacted in Tanzania in 1983 to regulate the use of ionizing radiation and protect people against its danger. The Act established a regulatory authority known as National Radiation Commission (NRC), which is the corporate body to enforce the law and regulations. From the beginning of 2000, the NRC has kept inventory of 200 and 324 radiation installations, and radiation sources and radioactive materials in the country, respectively; and has provided personnel monitoring services to 665 radiation workers. However, due to the trade liberalization that is currently being experienced in the country, the increase in the number of radiation practices is observed yearly. To cope with the situation, the whole system of notification, authorization, registration and licensing needs to be improved. The improvement has now started by amending the existing Protection from Radiation Act. (author)

  3. Quality assessment of allocation coordinates useful radiation source in control problems

    Directory of Open Access Journals (Sweden)

    Valery M. Ponyatsky

    2017-12-01

    Full Text Available It is offered in control problems to carry out assessment quality of the coordinates of useful radiation source allocated by means of video sensors on set of indicators, in particular, using probability of detection of desired signal. Traditionally the assessment of detection probability of useful radiation source is carried out proceeding from the assumption of the normal law distribution of probability density of desired signal and hindrance. The assessment of detection probability of useful radiation source which brightness changes under any law is considered. The estimates received in control process are used for choice of methods of processing of images, and also for their setup.

  4. 76 FR 76327 - Installation of Radiation Alarms for Rooms Housing Neutron Sources

    Science.gov (United States)

    2011-12-07

    ... of Radiation Alarms for Rooms Housing Neutron Sources AGENCY: Nuclear Regulatory Commission. ACTION... neutron sources. DATES: Submit comments by February 21, 2012. Comments received after this date will be... Safety for Research. Mr. Hamawy is concerned about the security of neutron sources. III. Petition The...

  5. Industrial point source CO2 emission strength estimation with aircraft measurements and dispersion modelling.

    Science.gov (United States)

    Carotenuto, Federico; Gualtieri, Giovanni; Miglietta, Franco; Riccio, Angelo; Toscano, Piero; Wohlfahrt, Georg; Gioli, Beniamino

    2018-02-22

    CO 2 remains the greenhouse gas that contributes most to anthropogenic global warming, and the evaluation of its emissions is of major interest to both research and regulatory purposes. Emission inventories generally provide quite reliable estimates of CO 2 emissions. However, because of intrinsic uncertainties associated with these estimates, it is of great importance to validate emission inventories against independent estimates. This paper describes an integrated approach combining aircraft measurements and a puff dispersion modelling framework by considering a CO 2 industrial point source, located in Biganos, France. CO 2 density measurements were obtained by applying the mass balance method, while CO 2 emission estimates were derived by implementing the CALMET/CALPUFF model chain. For the latter, three meteorological initializations were used: (i) WRF-modelled outputs initialized by ECMWF reanalyses; (ii) WRF-modelled outputs initialized by CFSR reanalyses and (iii) local in situ observations. Governmental inventorial data were used as reference for all applications. The strengths and weaknesses of the different approaches and how they affect emission estimation uncertainty were investigated. The mass balance based on aircraft measurements was quite succesful in capturing the point source emission strength (at worst with a 16% bias), while the accuracy of the dispersion modelling, markedly when using ECMWF initialization through the WRF model, was only slightly lower (estimation with an 18% bias). The analysis will help in highlighting some methodological best practices that can be used as guidelines for future experiments.

  6. Contaminant point source localization error estimates as functions of data quantity and model quality.

    Science.gov (United States)

    Hansen, Scott K; Vesselinov, Velimir V

    2016-10-01

    We develop empirically-grounded error envelopes for localization of a point contamination release event in the saturated zone of a previously uncharacterized heterogeneous aquifer into which a number of plume-intercepting wells have been drilled. We assume that flow direction in the aquifer is known exactly and velocity is known to within a factor of two of our best guess from well observations prior to source identification. Other aquifer and source parameters must be estimated by interpretation of well breakthrough data via the advection-dispersion equation. We employ high performance computing to generate numerous random realizations of aquifer parameters and well locations, simulate well breakthrough data, and then employ unsupervised machine optimization techniques to estimate the most likely spatial (or space-time) location of the source. Tabulating the accuracy of these estimates from the multiple realizations, we relate the size of 90% and 95% confidence envelopes to the data quantity (number of wells) and model quality (fidelity of ADE interpretation model to actual concentrations in a heterogeneous aquifer with channelized flow). We find that for purely spatial localization of the contaminant source, increased data quantities can make up for reduced model quality. For space-time localization, we find similar qualitative behavior, but significantly degraded spatial localization reliability and less improvement from extra data collection. Since the space-time source localization problem is much more challenging, we also tried a multiple-initial-guess optimization strategy. This greatly enhanced performance, but gains from additional data collection remained limited. Copyright © 2016. Published by Elsevier B.V.

  7. Range of applications of modern superconducting synchrotron radiation sources using the source planned at Karlsruhe (KSSQ) as an example

    International Nuclear Information System (INIS)

    Moser, H.O.

    1989-06-01

    The performance of the Karlsruhe synchrotron radiation source which was designed originally for X-ray deep-etch lithography comes close to that of first and second generation synchrotron radiation sources. The range of applications spanned by KSSQ is therefore quite similar to that of those machines. The present report displays a first collection of topics from the fields of surface analysis, solid state and materials research, and biology which could be investigated using KSSQ by interested groups coming from KfK and its surroundings. (orig.) [de

  8. Emissions of perfluorinated alkylated substances (PFAS) from point sources--identification of relevant branches.

    Science.gov (United States)

    Clara, M; Scheffknecht, C; Scharf, S; Weiss, S; Gans, O

    2008-01-01

    Effluents of wastewater treatment plants are relevant point sources for the emission of hazardous xenobiotic substances to the aquatic environment. One group of substances, which recently entered scientific and political discussions, is the group of the perfluorinated alkylated substances (PFAS). The most studied compounds from this group are perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS), which are the most important degradation products of PFAS. These two substances are known to be persistent, bioaccumulative and toxic (PBT). In the present study, eleven PFAS were investigated in effluents of municipal wastewater treatment plants (WWTP) and in industrial wastewaters. PFOS and PFOA proved to be the dominant compounds in all sampled wastewaters. Concentrations of up to 340 ng/L of PFOS and up to 220 ng/L of PFOA were observed. Besides these two compounds, perfluorohexanoic acid (PFHxA) was also present in nearly all effluents and maximum concentrations of up to 280 ng/L were measured. Only N-ethylperfluorooctane sulphonamide (N-EtPFOSA) and its degradation/metabolisation product perfluorooctane sulphonamide (PFOSA) were either detected below the limit of quantification or were not even detected at all. Beside the effluents of the municipal WWTPs, nine industrial wastewaters from six different industrial branches were also investigated. Significantly, the highest emissions or PFOS were observed from metal industry whereas paper industry showed the highest PFOA emission. Several PFAS, especially perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorododecanoic acid (PFDoA) and PFOS are predominantly emitted from industrial sources, with concentrations being a factor of 10 higher than those observed in the municipal WWTP effluents. Perfluorodecane sulphonate (PFDS), N-Et-PFOSA and PFOSA were not detected in any of the sampled industrial point sources. (c) IWA Publishing 2008.

  9. The IAEA's sub programme on the safety of radiation sources and the security of radioactive materials

    International Nuclear Information System (INIS)

    Ortiz, P.; Oresegun, M.; Bilbao, A.; Webb, G.A.M.; Cunninghan, R.

    1998-01-01

    In compliance with its mandate to establish standards of safety and to provide for their application with respect to radiation sources, the International Atomic Energy Agency has developed a subprogramme aimed at providing Member States guidance and assistance on achieving regulatory control and the safe use of the sources. The guidance addresses the establishment of a Regulatory Programme, with focus on a system for notification and authorization (registration and licensing) and inspection of radiation sources, including check lists for review of safety. It also includes methods for assessing its effectiveness of the Regulatory Programme and is complemented with tools for the management of data by the Regulatory Authority and Services to assist Member States in assessment and implementation of the programme. In addition, technical guidance for the safety of radiation sources includes both prospective and retrospective safety assessment. Retrospective methods have been used resulting in the publication and dissemination of information and lessons from accidents, both individual accident reports and lessons from collection of accident for the practices with major sources (industrial radiography, irradiators and radiotherapy). Prospective methods will include guidance on the application of the principles of radiation protection to potential exposure, as well as methods to apply the principles, such as identification and evaluation of scenarios. Practice specific reports will address the major radiation sources. A research programme will be dedicated to apply Probabilistic Safety Assessment (PSA) to radiation sources. (author)

  10. Fast computation of quadrupole and hexadecapole approximations in microlensing with a single point-source evaluation

    Science.gov (United States)

    Cassan, Arnaud

    2017-07-01

    The exoplanet detection rate from gravitational microlensing has grown significantly in recent years thanks to a great enhancement of resources and improved observational strategy. Current observatories include ground-based wide-field and/or robotic world-wide networks of telescopes, as well as space-based observatories such as satellites Spitzer or Kepler/K2. This results in a large quantity of data to be processed and analysed, which is a challenge for modelling codes because of the complexity of the parameter space to be explored and the intensive computations required to evaluate the models. In this work, I present a method that allows to compute the quadrupole and hexadecapole approximations of the finite-source magnification with more efficiency than previously available codes, with routines about six times and four times faster, respectively. The quadrupole takes just about twice the time of a point-source evaluation, which advocates for generalizing its use to large portions of the light curves. The corresponding routines are available as open-source python codes.

  11. Emissions and doses from sources of ionising radiation in the Netherlands: radiation policy monitoring

    International Nuclear Information System (INIS)

    Eleveld, H.; Pruppers, M.

    2002-01-01

    In 1997 the Ministry of Housing, Spatial Planning and the Environment requested RIVM to develop an information system for policy monitoring. One of the motives was that the European Union requires that the competent authorities of each member state ensure that dose estimates due to practices involving exposure to ionising radiation are made as realistic as possible for the population as a whole and for reference groups in all places where such groups may occur. Emissions of radionuclides and radiation to the environment can be classified as follows: (1) emissions to the atmosphere, (2) emissions to the aquatic system and (3) emission of external radiation from radioactive materials and equipment that produces ionising radiation. Released radioactivity is dispersed via exposure pathways, such as the atmosphere, deposition on the ground and farmland products, drinking water, fish products, etc. This leads to radiation doses due to inhalation, ingestion and exposure to external radiation. To assess the possible radiation doses different kinds of models are applied, varying from simple multiplications with dispersion coefficients, transfer coefficients and dose conversion coefficients to complex dispersion models. In this paper an overview is given of the human-induced radiation doses in the Netherlands. Also, trends in and the effect of policy on the radiation dose of members of the public are investigated. This paper is based on an RIVM report published recently. A geographical distribution of radiation risks due to routine releases for a typical year in the Netherlands was published earlier

  12. Radiation monitoring policy at the advanced light source

    International Nuclear Information System (INIS)

    Donahue, R.; Heinzelman, K.; Perdue, G.

    1998-01-01

    When the accelerator first began operation it was decided that, until we had the necessary dosimetry data to decide otherwise, we would badge the entire worker and experimental population. Each person was issued a dosimetry badge that contained 4 TLD elements. Badges were processed on a monthly basis. After three years of analyzing a total of 65,000 TLD elements, the decision was made to modify the radiation monitoring policy at the ALS. Only those individuals in the workforce that have any potential for exposure, no matter how small, would be badged. Subsequently, DOE conducted an independent review of the ALS radiation monitoring and dosimetry program. This review concluded that the ALS program, if expanded as proposed, would be adequate under the 10 CFR 835 Rule to establish radiation exposures to an acceptable level of confidence. The review team recommended the ALS provide more comprehensive documentation on the basis for its radiation protection and monitoring program. This document describes the technical justification for that program

  13. Natural sources of radiation exposure and the teaching of radioecology

    International Nuclear Information System (INIS)

    Anjos, R M; Veiga, R; Carvalho, C; Sanches, N; Estellita, L; Macario, K; Zanuto, P; Queiroz, E

    2008-01-01

    We have developed an experimental activity that introduces concepts of the natural ionizing radiation and its interaction with our contemporary environment that can be used with students from secondary to college level. The experiment is based on the use of traditional and cheap portable Geiger–Müller detectors as survey meters for in situ measurements

  14. Terahertz radiation source using a high-power industrial electron ...

    Indian Academy of Sciences (India)

    2017-03-27

    Mar 27, 2017 ... lasers and quantum cascade lasers, provide THz radia- tion with average output power of the order of ..... the computer code GINGER [45] to study the power growth and power spectrum of the spontaneous ... for radiation), time-dependent computer code, which is primarily developed to simulate FELs in ...

  15. Terahertz radiation source using a high-power industrial electron ...

    Indian Academy of Sciences (India)

    We propose that high-power electron beam from such an industrial linac can first pass through an undulator to generate useful terahertz (THz) radiation, and the spent electron beam coming out of the undulator can still be used for the intended industrial applications. This will enhance the utilization of a high-power industrial ...

  16. Terahertz radiation source using a high-power industrial electron ...

    Indian Academy of Sciences (India)

    High-power ( ∼ 100 k W ) industrial electron linear accelerators (linacs) are used for irradiations, e.g., for pasteurization of food products, disinfection of medical waste, etc.We propose that high-power electron beam from such an industrial linac can first pass through an undulator to generate useful terahertz (THz) radiation, ...

  17. Safety of radiation sources and security of radioactive materials. A Romanian approach

    International Nuclear Information System (INIS)

    Ghilea, S.; Coroianu, A.I.; Rodna, A.L.

    2001-01-01

    After a brief explanation on the scope of applications of nuclear energy and practices with ionizing radiation in Romania, the report explains the current national infrastructure for radiation safety making reference in particular to the National Commission for Nuclear Activities Control as the regulatory authority for the safety of radiation sources. The report also describes the existing legal framework, provides information on the list of normative acts in force, and on the system of authorization, inspection and enforcement, which operates effectively. (author)

  18. 21 CFR 179.21 - Sources of radiation used for inspection of food, for inspection of packaged food, and for...

    Science.gov (United States)

    2010-04-01

    ... information identifying the source of radiation. (ii) The maximum energy of radiation emitted by X-ray tube... CONSUMPTION (CONTINUED) IRRADIATION IN THE PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation... radiations at energy levels of not more than 2.2 million electron volts from one of the following isotopes...

  19. Kharkov 3-GeV pulse stretcher ring as a source of synchrotron radiation

    International Nuclear Information System (INIS)

    Boldyshev, V.F.; Gladkikh, P.I.; Grigor'ev, Y.N.; Guk, I.S.; Efimov, S.V.; Karnaukhov, I.M.; Kononenko, S.G.; Mocheshnikov, N.I.; Popkov, Y.P.; Tarasenko, A.S.; Telegin, Y.N.; Chechetenko, V.F.; Shcherbakov, A.A.; Titov, V.A.; Nagaenko, M.G.

    1989-01-01

    The article discusses the possibility of using the pulse stretcher ring, designed at the Kharkov Institute of Physics and Technology, as a synchrotron radiation source (SRS). Comparison is made between our SRS design parameters and those of other dedicated SRSs

  20. Licensing authority's control of radiation sources and nuclear materials in Brazil

    International Nuclear Information System (INIS)

    Binns, D.A.C.

    2002-01-01

    Full text: The Brazilian Nuclear Energy Commission is the national licensing authority and among its responsibilities is the control of nuclear materials and radiation sources. This control is carried out in three different ways: 1) Control of the import and export of nuclear materials and radiation sources. To be able to import or export any nuclear material or radiation source, the user has to have an explicit permission of the licensing authority. This is controlled by electronic means in which the user has to fill a special form found on the licensing authority's home page, where he has to fill in his name, license number, license number of his radiation protection officer and data of the material to be imported or exported. These data are checked with a data base that contains all the information of the licensed users and qualified personnel before authorization is emitted. The airport authorities have already installed x-ray machines to check all baggages entering or leaving the country. 2) Transport and transfer permit for radiation sources. In order to transport and/or transfer radiations sources and nuclear materials within the country, the user(s) have to submit an application to the licensing authority. The user(s) fill out an application form where he fills in his company's name, licensing I.D., radiation protection officer's name and I.D and identification of the sources involved. These information are checked with the licensing operations data before the operations is permitted. 3) Inspections and radiation monitoring systems. Routine and regulatory inspections are continuously carried out where the user's radiation sources and nuclear materials inventory are checked. Also the physical security and protection of these materials are verified. The installation of monitoring systems is an item that is being discussed with the airport authorities so as to increase the possibilities of detecting any illegal transport of these materials. (author)

  1. Computer program for source distribution process in radiation facility

    International Nuclear Information System (INIS)

    Al-Kassiri, H.; Abdul Ghani, B.

    2007-08-01

    Computer simulation for dose distribution using Visual Basic has been done according to the arrangement and activities of Co-60 sources. This program provides dose distribution in treated products depending on the product density and desired dose. The program is useful for optimization of sources distribution during loading process. there is good agreement between calculated data for the program and experimental data.(Author)

  2. Study for a 6 GeV undulator based synchrotron radiation source

    International Nuclear Information System (INIS)

    Vignola, G.; Barton, M.; Blumberg, R.; Galayda, J.; Krinsky, S.; Luccio, A.; Pellegrini, C.; van Steenbergen, A.; Wang, J.

    1985-01-01

    A partial study for a 6 GeV undulator based synchrotron radiation source for production of high brightness undulator radiation, in the A region, is presented. The basic lattice adopted for the storage ring is a hybrid FODO Chasman-Green lattice, making use of gradient in the dipoles. We discuss also the e beam current limits and the injection parameters

  3. Utilizations of intense pulsed neutron source in radiochemistry and radiation chemistry

    International Nuclear Information System (INIS)

    Shiokawa, Takanobu; Yoshihara, Kenji; Kaji, Harumi; Kusaka, Yuzuru; Tabata, Yoneho.

    1975-01-01

    Intense pulsed neutron sources is expected to supply more useful and fundamental informations in radiochemistry and radiation chemistry. Short-lived intermediate species may be detected and the mechanisms of radiation induced reactions will be elucidated more precisely. Analytical application of pulsed neutrons is also very useful. (auth.)

  4. Recent status on cobalt-60 gamma ray radiation sources production and its application in China

    International Nuclear Information System (INIS)

    Cao Zhijian; Song Yunjiang; Zhang Chunhua; Li Maoling

    1993-01-01

    This paper describes the status of Co-60 γ ray radiation sources and their application in China. At present, the production capacity of Co-60 γ ray radiation sources in China is about 11.1 PBq (0.3 MCi) per year. 5 years later, it is increased to 37 PBq (1 MCi) per year. The radioactivity of each source is 370 TBq - 740 TBq (1000-2000 Ci). There are over 150 Co-60 γ ray radiation facilities with total design capacity of over 370 PBq (10 MCi) and practical capacity of about 92.5 PBq (2.5 MCi) in operation. The number of Co-60 γ ray radiation facilities with practical capacity of over 3.7 PBq (0.1 MCi) is 14. The main applications of the Co-60 γ ray sources are radiation crosslinking, radiation sterilization of disposable medical supplies and food irradiation. The prospects for Co-60 γ ray radiation source application in China are good. (author)

  5. Permanent activity assuring safety of radiation sources used by the Ministry of Defense

    International Nuclear Information System (INIS)

    Schoulz, D.; Treguier, J.Y.

    1998-01-01

    Radiation sources used by the French Ministry of Defence are under a statutory surveillance. Different type of sources are bound by authorisation, acquisition and utilisation procedures coming from the French common law. Systematic and periodic controls are ruled by decree. Radiation sources used by all the organisations of the French Ministry of Defence are indexed by the S.P.R.A. (Army Radio Protection Service). The necessary stages for acquisition, possession, utilisation and elimination of each source may be controlled by the S.P.R.A. (author)

  6. The regulatory control of radiation sources in Australia -- The challenges of a federal system

    International Nuclear Information System (INIS)

    Loy, J.; Colgan, P.

    2001-01-01

    The report refers to the challenges that Australia is facing, as a federal nation having a Commonwealth Government and six States and two territories, in establishing appropriate regulatory control of radiation sources. Information on the national inventory of radiation sources and existing regulatory infrastructure, including the system of notification, registration, licensing, inspection and enforcement, is explained in the report. The national provisions for the management of disused sources; the planning, preparedness and response to abnormal events and emergencies; the recovery of control over orphan sources; and education and training; are specifically emphasized. (author)

  7. Building an open-source simulation platform of acoustic radiation force-based breast elastography

    Science.gov (United States)

    Wang, Yu; Peng, Bo; Jiang, Jingfeng

    2017-03-01

    Ultrasound-based elastography including strain elastography, acoustic radiation force impulse (ARFI) imaging, point shear wave elastography and supersonic shear imaging (SSI) have been used to differentiate breast tumors among other clinical applications. The objective of this study is to extend a previously published virtual simulation platform built for ultrasound quasi-static breast elastography toward acoustic radiation force-based breast elastography. Consequently, the extended virtual breast elastography simulation platform can be used to validate image pixels with known underlying soft tissue properties (i.e. ‘ground truth’) in complex, heterogeneous media, enhancing confidence in elastographic image interpretations. The proposed virtual breast elastography system inherited four key components from the previously published virtual simulation platform: an ultrasound simulator (Field II), a mesh generator (Tetgen), a finite element solver (FEBio) and a visualization and data processing package (VTK). Using a simple message passing mechanism, functionalities have now been extended to acoustic radiation force-based elastography simulations. Examples involving three different numerical breast models with increasing complexity—one uniform model, one simple inclusion model and one virtual complex breast model derived from magnetic resonance imaging data, were used to demonstrate capabilities of this extended virtual platform. Overall, simulation results were compared with the published results. In the uniform model, the estimated shear wave speed (SWS) values were within 4% compared to the predetermined SWS values. In the simple inclusion and the complex breast models, SWS values of all hard inclusions in soft backgrounds were slightly underestimated, similar to what has been reported. The elastic contrast values and visual observation show that ARFI images have higher spatial resolution, while SSI images can provide higher inclusion-to-background contrast

  8. Impacts by point and diffuse micropollutant sources on the stream water quality at catchment scale

    Science.gov (United States)

    Petersen, M. F.; Eriksson, E.; Binning, P. J.; Bjerg, P. L.

    2012-04-01

    The water quality of surface waters is threatened by multiple anthropogenic pollutants and the large variety of pollutants challenges the monitoring and assessment of the water quality. The aim of this study was to characterize and quantify both point and diffuse sources of micropollutants impacting the water quality of a stream at catchment scale. Grindsted stream in western Jutland, Denmark was used as a study site. The stream passes both urban and agricultural areas and is impacted by severe groundwater contamination in Grindsted city. Along a 12 km reach of Grindsted stream, the potential pollution sources were identified including a pharmaceutical factory site with a contaminated old drainage ditch, two waste deposits, a wastewater treatment plant, overflow structures, fish farms, industrial discharges and diffuse agricultural and urban sources. Six water samples were collected along the stream and analyzed for general water quality parameters, inorganic constituents, pesticides, sulfonamides, chlorinated solvents, BTEXs, and paracetamol and ibuprofen. The latter two groups were not detected. The general water quality showed typical conditions for a stream in western Jutland. Minor impacts by releases of organic matter and nutrients were found after the fish farms and the waste water treatment plant. Nickel was found at concentrations 5.8 - 8.8 μg/l. Nine pesticides and metabolites of both agricultural and urban use were detected along the stream; among these were the two most frequently detected and some rarely detected pesticides in Danish water courses. The concentrations were generally consistent with other findings in Danish streams and in the range 0.01 - 0.09 μg/l; except for metribuzin-diketo that showed high concentrations up to 0.74 μg/l. The groundwater contamination at the pharmaceutical factory site, the drainage ditch and the waste deposits is similar in composition containing among others sulfonamides and chlorinated solvents (including vinyl

  9. Determining the temperature and density distribution from a Z-pinch radiation source

    International Nuclear Information System (INIS)

    Matuska, W.; Lee, H.

    1997-01-01

    High temperature radiation sources exceeding one hundred eV can be produced via z-pinches using currently available pulsed power. The usual approach to compare the z-pinch simulation and experimental data is to convert the radiation output at the source, whose temperature and density distributions are computed from the 2-D MHD code, into simulated data such as a spectrometer reading. This conversion process involves a radiation transfer calculation through the axially symmetric source, assuming local thermodynamic equilibrium (LTE), and folding the radiation that reaches the detector with the frequency-dependent response function. In this paper the authors propose a different approach by which they can determine the temperature and density distributions of the radiation source directly from the spatially resolved spectral data. This unfolding process is reliable and unambiguous for the ideal case where LTE holds and the source is axially symmetric. In reality, imperfect LTE and axial symmetry will introduce inaccuracies into the unfolded distributions. The authors use a parameter optimization routine to find the temperature and density distributions that best fit the data. They know from their past experience that the radiation source resulting from the implosion of a thin foil does not exhibit good axial symmetry. However, recent experiments carried out at Sandia National Laboratory using multiple wire arrays were very promising to achieve reasonably good symmetry. For these experiments the method will provide a valuable diagnostic tool

  10. Determining the temperature and density distribution from a Z-pinch radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Matuska, W.; Lee, H.

    1997-11-01

    High temperature radiation sources exceeding one hundred eV can be produced via z-pinches using currently available pulsed power. The usual approach to compare the z-pinch simulation and experimental data is to convert the radiation output at the source, whose temperature and density distributions are computed from the 2-D MHD code, into simulated data such as a spectrometer reading. This conversion process involves a radiation transfer calculation through the axially symmetric source, assuming local thermodynamic equilibrium (LTE), and folding the radiation that reaches the detector with the frequency-dependent response function. In this paper the authors propose a different approach by which they can determine the temperature and density distributions of the radiation source directly from the spatially resolved spectral data. This unfolding process is reliable and unambiguous for the ideal case where LTE holds and the source is axially symmetric. In reality, imperfect LTE and axial symmetry will introduce inaccuracies into the unfolded distributions. The authors use a parameter optimization routine to find the temperature and density distributions that best fit the data. They know from their past experience that the radiation source resulting from the implosion of a thin foil does not exhibit good axial symmetry. However, recent experiments carried out at Sandia National Laboratory using multiple wire arrays were very promising to achieve reasonably good symmetry. For these experiments the method will provide a valuable diagnostic tool.

  11. The electromagnetic radiation from simple sources in the presence of a homogeneous dielectric sphere

    Science.gov (United States)

    Mason, V. B.

    1973-01-01

    In this research, the effect of a homogeneous dielectric sphere on the electromagnetic radiation from simple sources is treated as a boundary value problem, and the solution is obtained by the technique of dyadic Green's functions. Exact representations of the electric fields in the various regions due to a source located inside, outside, or on the surface of a dielectric sphere are formulated. Particular attention is given to the effect of sphere size, source location, dielectric constant, and dielectric loss on the radiation patterns and directivity of small spheres (less than 5 wavelengths in diameter) using the Huygens' source excitation. The computed results are found to closely agree with those measured for waveguide-excited plexiglas spheres. Radiation patterns for an extended Huygens' source and for curved electric dipoles located on the sphere's surface are also presented. The resonance phenomenon associated with the dielectric sphere is studied in terms of the modal representation of the radiated fields. It is found that when the sphere is excited at certain frequencies, much of the energy is radiated into the sidelobes. The addition of a moderate amount of dielectric loss, however, quickly attenuates this resonance effect. A computer program which may be used to calculate the directivity and radiation pattern of a Huygens' source located inside or on the surface of a lossy dielectric sphere is listed.

  12. Analytical calculation of the solid angle defined by a cylindrical detector and a point cosine source with parallel axes

    OpenAIRE

    Prata, M. J.

    2003-01-01

    We derive analytical expressions for the solid angle subtended by a right finite circular cylinder at a point source with cosine angular distribution in the case where the source direction is parallel to the cylinder axis. As a subsidiary result, an expression for the solid angle subtended by a disc detector at a spread disc source is also provided, in the case where the two discs have a common symmetry axis which is also coincident with the source direction.

  13. Risk-based prioritization of ground water threatening point sources at catchment and regional scales

    DEFF Research Database (Denmark)

    Overheu, Niels Døssing; Tuxen, Nina; Flyvbjerg, John

    2014-01-01

    framework has been developed to enable a systematic and transparent risk assessment and prioritization of contaminant point sources, considering the local, catchment, or regional scales (Danish EPA, 2011, 2012). The framework has been tested in several catchments in Denmark with different challenges...... and needs, and two of these are presented. Based on the lessons learned, the Danish EPA has prepared a handbook to guide the user through the steps in a risk-based prioritization (Danish EPA, 2012). It provides guidance on prioritization both in an administratively defined area such as a Danish Region...... of the results are presented using the case studies as examples. The methodology was developed by a broad industry group including the Danish EPA, the Danish Regions, the Danish Nature Agency, the Technical University of Denmark, and consultants — and the framework has been widely accepted by the professional...

  14. Improvement of correlation-based centroiding methods for point source Shack-Hartmann wavefront sensor

    Science.gov (United States)

    Li, Xuxu; Li, Xinyang; wang, Caixia

    2018-03-01

    This paper proposes an efficient approach to decrease the computational costs of correlation-based centroiding methods used for point source Shack-Hartmann wavefront sensors. Four typical similarity functions have been compared, i.e. the absolute difference function (ADF), ADF square (ADF2), square difference function (SDF), and cross-correlation function (CCF) using the Gaussian spot model. By combining them with fast search algorithms, such as three-step search (TSS), two-dimensional logarithmic search (TDL), cross search (CS), and orthogonal search (OS), computational costs can be reduced drastically without affecting the accuracy of centroid detection. Specifically, OS reduces calculation consumption by 90%. A comprehensive simulation indicates that CCF exhibits a better performance than other functions under various light-level conditions. Besides, the effectiveness of fast search algorithms has been verified.

  15. How to mitigate pesticides point sources pollution at the EU level?

    OpenAIRE

    Bonicelli, B.; Laplana, R.; Vaçulik, A.; Maillet-Mezeray, J.; Roetelle, M.; Palagos, B.; Dejean, C.

    2008-01-01

    International audience; Pour réduire les pollutions ponctuelles par les produits de protection des plantes (PPPs) un recueil de Bonnes Pratiques Agricoles (BPAs) a été élaboré dans le cdar du projet Européen TOPPS (Training Operators to prevent Pollution from Point Source). Le bon comportement des opérateurs a été identifié comme le facteur clé pour réduire les risques de pollutions ponctuelles. A l'échelle européenne (A0 pays), une enquête de sensibilité de l'ensemble des décideurs et acteur...

  16. Turbulent gravitational convection from a point source in a non-uniformly stratified environment

    Science.gov (United States)

    Caulfield, C. P.; Woods, Andrew W.

    1998-04-01

    We examine the turbulent gravitational convection which develops above a point source of buoyant fluid in a stably stratified environment in which the buoyancy frequency varies with height according to N2=N2s (z/zs)[beta]. This generalizes the classical model of turbulent buoyant plumes rising through uniform and uniformly stratified environments originally developed by Morton et al. (1956). By analogy, the height of rise of a plume with initial buoyancy flux Fs has the form Hp= Ap[epsilon]p[minus sign]1/2Fs1/4Ns[minus sign]3/4hp ([lambda], [beta]) where [epsilon]p is the entrainment constant for plume motion, Ap is an O(1) constant, and the non-dimensional plume height, hp is a function of &[lambda]=Ap[epsilon]p[minus sign]1/2Fs1/4Ns[minus sign]3/4/zs and [beta].

  17. Preliminary limits on the flux of muon neutrinos from extraterrestrial point sources

    International Nuclear Information System (INIS)

    Bionta, R.M.; Blewitt, G.; Bratton, C.B.

    1985-01-01

    We present the arrival directions of 117 upward-going muon events collected with the IMB proton lifetime detector during 317 days of live detector operation. The rate of upward-going muons observed in our detector was found to be consistent with the rate expected from atmospheric neutrino production. The upper limit on the total flux of extraterrestrial neutrinos >1 GeV is 2 -sec. Using our data and a Monte Carlo simulation of high energy muon production in the earth surrounding the detector, we place limits on the flux of neutrinos from a point source in the Vela X-2 system of 2 -sec with E > 1 GeV. 6 refs., 5 figs

  18. Simulation of agricultural non-point source pollution in Xichuan by using SWAT model

    Science.gov (United States)

    Xing, Linan; Zuo, Jiane; Liu, Fenglin; Zhang, Xiaohui; Cao, Qiguang

    2018-02-01

    This paper evaluated the applicability of using SWAT to access agricultural non-point source pollution in Xichuan area. In order to build the model, DEM, soil sort and land use map, climate monitoring data were collected as basic database. The SWAT model was calibrated and validated for the SWAT was carried out using streamflow, suspended solids, total phosphorus and total nitrogen records from 2009 to 2011. Errors, coefficient of determination and Nash-Sutcliffe coefficient were considered to evaluate the applicability. The coefficient of determination were 0.96, 0.66, 0.55 and 0.66 for streamflow, SS, TN, and TP, respectively. Nash-Sutcliffe coefficient were 0.93, 0.5, 0.52 and 0.63, respectively. The results all meet the requirements. It suggested that the SWAT model can simulate the study area.

  19. Radiation as a source of information on matter properties

    International Nuclear Information System (INIS)

    2001-01-01

    The report is a review of applications of ionizing radiation in industry, environment protection and biology. Many examples of the use of radiation technologies, nuclear instruments, radiotracers, and nuclear analytical methods in Poland and elsewhere have been presented. The report has been divided into 12 subject chapters; age estimation - study on the objects age; investigations of copper ores enrichment processes; study of object dynamics; application of radiotracer method for tightness control and leakage localization in industrial objects; radiotracer investigations of natural and artificial water reservoirs; radioisotope measuring instruments; radiometric instruments and measuring systems in mining and energetics; instruments for radiotracer investigations; well logging; application of neutron activation analysis; application of Moessbauer spectroscopy; application of nuclear techniques for conservation and identification of art objects

  20. Lesson from a 60Co source radiation accident

    International Nuclear Information System (INIS)

    Guo Yong; Zhang Wenzhong

    2002-01-01

    A serious radiation accident happened an a 60 Co irradiation facility in Shanghai. 7 workers were uniformly exposed acutely. An investigation was done after the accident and a conclusion was achieved that the irregular operation was the direct reason for the accident. The operation of these workers did not comply with the requirements specified in the national standards-- 60 irradiation facility>> which demands that the examination should be done every day before operation, and the irradiation facility does not stop running when the auto-lock safety system on that facility has been removed. Some lessons should be drawn from the accident: popularizing the culture of safety, enhancing the law of safety, and ensuring the operation of radiation devices within the demands of safety

  1. Nonrelativistic electron bunch train for coherently enhanced terahertz radiation sources

    International Nuclear Information System (INIS)

    Li Yuelin; Kim, Kwang-Je

    2008-01-01

    We propose to generate a train of prebunched electron beams for producing coherently enhanced Smith-Purcell radiation [S. J. Smith and E. M. Purcell, Phys. Rev. 92, 1069 (1953)] in the terahertz wavelength range. In this scheme, a train of picosecond laser pulses is produced to drive a photoemission gun to generate a train of 50 keV electron pulses. The parameters are chosen so that the space-charge effect does not destroy the pulse time structure. Smith-Purcell radiation from the electron pulse train is enhanced due both to the short length of the individual electron bunch and to the repetitive structure of the beam. Example systems producing coherent terahertz power at about 1 mW are described

  2. Polymer research at synchrotron radiation sources: symposium proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Russell, T.P.; Goland, A.N. (eds.)

    1985-01-01

    The twenty-two papers are arranged into eleven sessions entitled: general overviews; time-resolved x-ray scattering; studies using fluorescence, ion-containing polymers; time-resolved x-ray scattering; novel applications of synchrotron radiation; phase transitions in polymers; x-ray diffraction on polymers; recent detector advances; complementary light, x-ray and neutron studies; and neutron scattering studies. Seven of the papers are processed separately; three of the remainder have been previously processed. (DLC)

  3. Polymer research at synchrotron radiation sources: symposium proceedings

    International Nuclear Information System (INIS)

    Russell, T.P.; Goland, A.N.

    1985-01-01

    The twenty-two papers are arranged into eleven sessions entitled: general overviews; time-resolved x-ray scattering; studies using fluorescence, ion-containing polymers; time-resolved x-ray scattering; novel applications of synchrotron radiation; phase transitions in polymers; x-ray diffraction on polymers; recent detector advances; complementary light, x-ray and neutron studies; and neutron scattering studies. Seven of the papers are processed separately; three of the remainder have been previously processed

  4. Rebuilding and Modeling of a Thermal Radiation Source

    Science.gov (United States)

    1994-08-01

    radiant energy coming form the particles, and the heat transfer mechanism is mostly convective. This process creates a large flame radiating at a high...personnel generated a set of objectives for an improved TRS. The need for the TRS to reprodce the nuclear thermal pulse of Figure 1 was relaxed. A nulear ...pulse was chosen for the TRS, matching the total radiant energy , or fluev e, on the target. For maximum control, the new .IS would emit at its peak

  5. Detection of Sources of Harmful Radiation using Portable Sensors

    Science.gov (United States)

    2016-05-01

    background radiation. This is a common circumstance in cluttered urban envi- ronments. It is also in these environments where weapons such as dirty bombs...nuclear materials is key in preventing the proliferation of nuclear weapons and nuclear terror attacks. Terrorist organizations and even certain...countries acquiring nuclear weapons is a dangerous situation for the entire international community[12]. The smuggling of weapons such as tactical nuclear

  6. Field-scale operation of methane biofiltration systems to mitigate point source methane emissions

    International Nuclear Information System (INIS)

    Hettiarachchi, Vijayamala C.; Hettiaratchi, Patrick J.; Mehrotra, Anil K.; Kumar, Sunil

    2011-01-01

    Methane biofiltration (MBF) is a novel low-cost technique for reducing low volume point source emissions of methane (CH 4 ). MBF uses a granular medium, such as soil or compost, to support the growth of methanotrophic bacteria responsible for converting CH 4 to carbon dioxide (CO 2 ) and water (H 2 O). A field research program was undertaken to evaluate the potential to treat low volume point source engineered CH 4 emissions using an MBF at a natural gas monitoring station. A new comprehensive three-dimensional numerical model was developed incorporating advection-diffusive flow of gas, biological reactions and heat and moisture flow. The one-dimensional version of this model was used as a guiding tool for designing and operating the MBF. The long-term monitoring results of the field MBF are also presented. The field MBF operated with no control of precipitation, evaporation, and temperature, provided more than 80% of CH 4 oxidation throughout spring, summer, and fall seasons. The numerical model was able to predict the CH 4 oxidation behavior of the field MBF with high accuracy. The numerical model simulations are presented for estimating CH 4 oxidation efficiencies under various operating conditions, including different filter bed depths and CH 4 flux rates. The field observations as well as numerical model simulations indicated that the long-term performance of MBFs is strongly dependent on environmental factors, such as ambient temperature and precipitation. - Highlights: → One-dimensional version of the model was used as a guiding tool for designing and operating the MBF. → Mathematical model predicted CH 4 oxidation behaviors of the field MBF with high accuracy i.e. (> 80 %). → Performance of MBF is dependent on ambient temperature and precipitation. - The developed numerical model simulations and field observations for estimating CH 4 oxidation efficiencies under various operating conditions indicate that the long-term performance of MBFs is strongly

  7. Carbon dioxide capture and separation techniques for advanced power generation point sources

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H.W.; Luebke, D.R.; Morsi, B.I.; Heintz, Y.J.; Jones, K.L.; Ilconich, J.B.

    2006-09-01

    The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (postcombustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle – IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Fabrication techniques and mechanistic studies for hybrid membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic silanes incorporated into an alumina support or ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. An overview of two novel techniques is presented along with a research progress status of each technology.

  8. Carbon Dioxide Capture and Separation Techniques for Gasification-based Power Generation Point Sources

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H.W.; Luebke, D.R.; Jones, K.L.; Morsi, B.I. (Univ. of Pittsburgh, PA); Heintz, Y.J. (Univ. of Pittsburgh, PA); Ilconich, J.B. (Parsons)

    2007-06-01

    The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and reduced costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (post-combustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle or IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Pertaining to another separation technology, fabrication techniques and mechanistic studies for membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. Finally, dry, regenerable processes based on sorbents are additional techniques for CO2 capture from fuel gas. An overview of these novel techniques is presented along with a research progress status of technologies related to membranes and physical solvents.

  9. Radiation Tolerant Low Power Precision Time Source, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The availability of small, low power atomic clocks is now a reality for ground-based and airborne navigation systems. Kernco's Low Power Precision Time Source...

  10. Developing point of care and high-throughput biological assays for determining absorbed radiation dose

    International Nuclear Information System (INIS)

    Joiner, Michael C.; Thomas, Robert A.; Grever, William E.; Smolinski, Joseph M.; Divine, George W.; Konski, Andre A.; Auner, Gregory W.; Tucker, James D.

    2011-01-01

    Background and purpose: Systems are being developed to assess radiation exposure based on leukocyte mRNA levels obtained by finger-stick sampling. The goal is to provide accurate detection of dose exposures up to 10 Gy for up to 1 week following exposure. We previously showed that specific mRNA sequences increase expression within an hour of exposure, and some genes continue to show elevated expression for at least 24 h. Full duration and dose-dependence of this persistence remain to be determined. In the present study, real-time quantitative PCR (qPCR) was used to determine changes in gene expression. qPCR can rapidly analyze small blood samples and could be adopted into a field-portable instrument that provides a radiation dose readout within 30 min. Materials and methods: From previous microarray analysis of 21,000 genes expressed in human lymphoblastoid cells 4 h post-irradiation (0–4 Gy), 118 genes were selected for evaluation by qPCR of gene expression in the leukocytes of human blood irradiated in vitro with doses of 0–10 Gy from a Co-60 gamma source at a dose rate of 30 cGy/min. Results: Blood from 20 normal healthy human donors yielded many mRNA sequences that could be used for radiation dosimetry. We observed four genes with large and persistent responses following exposure: ASTN2, CDKN1A, GADD45A, and GDF15. Five genes were identified as reliably non-responsive and were suitable for use as endogenous controls: DPM1, ITFG1, MAP4, PGK1, and SLC25A36; of these, ITFG1 was used for the analyses presented here. A significant dose-responsive increase in expression occurred for CDKN1A that was >16-fold at 10 Gy and 3-fold at 0.5 Gy compared to pre-irradiation values. Conclusions: These data show large, selective increases in mRNA transcript levels that persist for at least 48 h after single exposures between 0.5 and 10 Gy. Stable, non-responsive mRNA sequences for use as endogenous controls were also identified. These results indicate that following further

  11. Developing a GIS-Based Model to Track Potential Point and Non-Point Sources of Urban Stream Pollution

    Science.gov (United States)

    Day, C. A.

    2014-12-01

    Urban streams are often characterized by diminished water quality resulting from an increase in polluted runoff from impervious surfaces. Storm activity further reduces urban stream water quality by temporarily increasing stormwater discharge from sewer overflows. This will often manifest itself in rapid declines of dissolved oxygen and peaks in specific conductivity in response to a rising biochemical oxygen demand which slowly recovers as the pollution load is washed through the stream system. This research developed a GIS-based model to track potential sources of pollution based on the dissolved oxygen and specific conductivity response of urban streams to a series of storm events, within the city of Louisville, Kentucky. Watershed outlet hydrographs were first obtained to determine the lag time of dissolved oxygen drops and specific conductivity peaks in response to set of storm events. Using a digital elevation model and the National Landcover Database, 10m resolution rasters were then created which calculated slope and flow direction/accumulation for both open channel and overland flow conditions across the watersheds. The rasters were merged and converted to flow velocities using a series of storms with different intensities. The final step utilized the Flow Length tool in ArcGIS which calculated the travel time to the watershed outlets from each pixel weighted by the open channel and overland flow conditions. Potential pollution sources could then be located by matching the dissolved oxygen and specific conductivity response lag times to the associated watershed travel times.

  12. Atmospheric observations and inverse modelling for quantifying emissions of point-source synthetic greenhouse gases in East Asia

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Muhle, Jens; Weiss, Ray

    2017-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacements that are emitted from fugitive and mobile emission sources, these gases are mostly emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane (HCFC-22) factories (HFC-23). In this work we show that atmospheric measurements can serve as a basis to calculate emissions of these gases and to highlight emission 'hotspots'. We use measurements from one Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites at Gosan on Jeju Island in the Republic of Korea. This site measures CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over seven years between 2008 and 2015. We show that our 'top-down' emission estimates for NF3 and CF4 are significantly larger than 'bottom-up' estimates in the EDGAR emissions inventory (edgar.jrc.ec.europa.eu). For example we calculate South Korean emissions of CF4 in 2010 to be 0.29±0.04 Gg/yr, which is significantly larger than the Edgar prior emissions of 0.07 Gg/yr. Further, inversions for several separate years indicate that emission hotspots can be found without prior spatial information. At present these gases make a small contribution to global radiative forcing, however, given

  13. Morphology, chemistry and distribution of neoformed spherulites in agricultural land affected by metallurgical point-source pollution.

    Science.gov (United States)

    Leguédois, Sophie; Van Oort, Folkert; Jongmans, Toine; Chevallier, Pierre

    2004-07-01

    Metal distribution patterns in superficial soil horizons of agricultural land affected by metallurgical point-source pollution were studied using optical and electron microscopy, synchrotron radiation and spectroscopy analyses. The site is located in northern France, at the center of a former entry lane to a bunker of World War II, temporarily paved with coarse industrial waste fragments and removed at the end of the war. Thin sections made from undisturbed soil samples from A and B horizons were studied. Optical microscopy revealed the occurrence of yellow micrometer-sized (Ap horizon) and red decamicrometer-sized spherulites (AB, B(1)g horizons) as well as distinct distribution patterns. The chemical composition of the spherulites was dominated by Fe, Mn, Zn, Pb, Ca, and P. Comparison of calculated Zn stocks, both in the groundmass and in spherulites, showed a quasi-exclusive Zn accumulation in these neoformed features. Their formation was related to several factors: (i) liberation of metal elements due to weathering of waste products, (ii) Ca and P supply from fertilizing practices, (iii) co-precipitation of metal elements and Ca and P in a porous soil environment, after slow exudation of a supersaturated soil solution in more confined mineral media.

  14. An accurate discontinuous Galerkin method for solving point-source Eikonal equation in 2-D heterogeneous anisotropic media

    Science.gov (United States)

    Le Bouteiller, P.; Benjemaa, M.; Métivier, L.; Virieux, J.

    2018-03-01

    Accurate numerical computation of wave traveltimes in heterogeneous media is of major interest for a large range of applications in seismics, such as phase identification, data windowing, traveltime tomography and seismic imaging. A high level of precision is needed for traveltimes and their derivatives in applications which require quantities such as amplitude or take-off angle. Even more challenging is the anisotropic case, where the general Eikonal equation is a quartic in the derivatives of traveltimes. Despite their efficiency on Cartesian meshes, finite-difference solvers are inappropriate when dealing with unstructured meshes and irregular topographies. Moreover, reaching high orders of accuracy generally requires wide stencils and high additional computational load. To go beyond these limitations, we propose a discontinuous-finite-element-based strategy which has the following advantages: (1) the Hamiltonian formalism is general enough for handling the full anisotropic Eikonal equations; (2) the scheme is suitable for any desired high-order formulation or mixing of orders (p-adaptivity); (3) the solver is explicit whatever Hamiltonian is used (no need to find the roots of the quartic); (4) the use of unstructured meshes provides the flexibility for handling complex boundary geometries such as topographies (h-adaptivity) and radiation boundary conditions for mimicking an infinite medium. The point-source factorization principles are extended to this discontinuous Galerkin formulation. Extensive tests in smooth analytical media demonstrate the high accuracy of the method. Simulations in strongly heterogeneous media illustrate the solver robustness to realistic Earth-sciences-oriented applications.

  15. Point Source contamination approach for hydrological risk assessment of a major hypothetical accident from second research reactor at Inshas site

    International Nuclear Information System (INIS)

    Sadek, M.A.; Tawfik, F.S.

    2002-01-01

    The point source contamination mechanism and the deterministic conservative approach have been implemented to demonstrate the hazards of hydrological pollution due to a major hypothetical accident in the second research reactor at Inshas. The radioactive inventory is assumed to be dissolved in 75% of the cooling water (25% are lost) and comes directly into contact with ground water and moved down gradient. Five radioisotopes(I-129, Sr-90, Ru-106, Cs-134 and Cs-137) of the entire inventory are found to be highly durable and represent vulnerability in the environment. Their downstream spread indices; C max : maximum concentration at the focus of the moving ellipse, delta: pollution duration at different distances, A:polluted area at different distances and X min : safety distance from the reactor, were calculated based on analytical solutions of the convection-dispersion partial differential equation for absorbable and decaying species. The largest downstream contamination range was found for Sr-90 and Ru-106 but still no potential. The geochemical and hydrological parameters of the water bearing formations play a great role in buffering and limiting the radiation effects. These reduce the retention time of the radioisotopes several order of magnitudes in the polluted distances. Sensitivity analysis of the computed pollution ranges shows low sensitivity to possible potential for variations activity of nuclide inventory, dispersivity and saturated thickness and high sensitivity for possible variations in groundwater velocity and retention factors

  16. Astronomers Detect Powerful Bursting Radio Source Discovery Points to New Class of Astronomical Objects

    Science.gov (United States)

    2005-03-01

    Astronomers at Sweet Briar College and the Naval Research Laboratory (NRL) have detected a powerful new bursting radio source whose unique properties suggest the discovery of a new class of astronomical objects. The researchers have monitored the center of the Milky Way Galaxy for several years and reveal their findings in the March 3, 2005 edition of the journal, “Nature”. This radio image of the central region of the Milky Way Galaxy holds a new radio source, GCRT J1745-3009. The arrow points to an expanding ring of debris expelled by a supernova. CREDIT: N.E. Kassim et al., Naval Research Laboratory, NRAO/AUI/NSF Principal investigator, Dr. Scott Hyman, professor of physics at Sweet Briar College, said the discovery came after analyzing some additional observations from 2002 provided by researchers at Northwestern University. “"We hit the jackpot!” Hyman said referring to the observations. “An image of the Galactic center, made by collecting radio waves of about 1-meter in wavelength, revealed multiple bursts from the source during a seven-hour period from Sept. 30 to Oct. 1, 2002 — five bursts in fact, and repeating at remarkably constant intervals.” Hyman, four Sweet Briar students, and his NRL collaborators, Drs. Namir Kassim and Joseph Lazio, happened upon transient emission from two radio sources while studying the Galactic center in 1998. This prompted the team to propose an ongoing monitoring program using the National Science Foundation’s Very Large Array (VLA) radio telescope in New Mexico. The National Radio Astronomy Observatory, which operates the VLA, approved the program. The data collected, laid the groundwork for the detection of the new radio source. “Amazingly, even though the sky is known to be full of transient objects emitting at X- and gamma-ray wavelengths,” NRL astronomer Dr. Joseph Lazio pointed out, “very little has been done to look for radio bursts, which are often easier for astronomical objects to produce

  17. IAEA standard syllabus of a course to acquire competence on ionizing radiation sources activities

    International Nuclear Information System (INIS)

    Antonova, M.

    2004-01-01

    The specialized training for Ionizing Radiation Sources (IRS) activities is conducted according to educational syllabuses developed for every job position in compliance with art. 12, (3) of new Regulation of the conditions and procedure for acquiring professional qualification and for the procedure for issuing licenses for specialized training and certificates for qualification for use of nuclear energy. A brief review of the modular structure of the standard syllabus of the Postgraduate Educational Course in Radiation Protection and the Safe Use of Radiation Sources is presented in this paper. The content and level of training for categories of persons engaged in different practices are also listed

  18. The space-time outside a source of gravitational radiation: the axially symmetric null fluid

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, L. [Universidad Central de Venezuela, Escuela de Fisica, Facultad de Ciencias, Caracas (Venezuela, Bolivarian Republic of); Universidad de Salamanca, Instituto Universitario de Fisica Fundamental y Matematicas, Salamanca (Spain); Di Prisco, A. [Universidad Central de Venezuela, Escuela de Fisica, Facultad de Ciencias, Caracas (Venezuela, Bolivarian Republic of); Ospino, J. [Universidad de Salamanca, Departamento de Matematica Aplicada and Instituto Universitario de Fisica Fundamental y Matematicas, Salamanca (Spain)

    2016-11-15

    We carry out a study of the exterior of an axially and reflection symmetric source of gravitational radiation. The exterior of such a source is filled with a null fluid produced by the dissipative processes inherent to the emission of gravitational radiation, thereby representing a generalization of the Vaidya metric for axially and reflection symmetric space-times. The role of the vorticity, and its relationship with the presence of gravitational radiation is put in evidence. The spherically symmetric case (Vaidya) is, asymptotically, recovered within the context of the 1 + 3 formalism. (orig.)

  19. The energy sources and nuclear energy - The point of view of the Belgian Catholic Church

    International Nuclear Information System (INIS)

    Hoenraet, Christian

    2000-01-01

    The problems related to the environment are reported regularly to the public by means of the newspapers, on radio and television. The story is the product of a journalistic process and in general does not bear much resemblance to the original event. The rate and type of reportage depend not only on the body of data available to the journalist but on the information sources the journalist chosen to use. The same story is reported in a positive or negative way. Finally people are overwhelmed by contradictory information and became uncertain or frightened. In order to provide the general public with objective information about nuclear energy in particular and to made a statement about the position of the Belgian Catholic Church concerning this matter, the results of the study were published in Dutch under the form of a book with the title 'The Energy Sources and Nuclear Energy - Comparative analysis and ethical thoughts written the same author. Thia paper is a short survey of the results of the study and to present the point of view of the Belgian Catholic Church in the energy debate

  20. NOx emissions from large point sources: variability in ozone production, resulting health damages and economic costs

    International Nuclear Information System (INIS)

    Mauzerall, D.L.; Namsoug Kim

    2005-01-01

    We present a proof-of-concept analysis of the measurement of the health damage of ozone (O 3 ) produced from nitrogen oxides (NO x =NO+NO 2 ) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air quality Model with Extensions (CAMx), to quantify the variable impact that a fixed quantity of NO x emitted from individual sources can have on the downwind concentration of surface O 3 , depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting O 3 -related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used 'cap and trade' approach to NO x regulation, which presumes that shifts of emission over time and space, holding the total fixed over the course of the summer O 3 season, will have minimal effect on the environmental outcome. By contrast, we show that a shift of a unit of NO x emissions from one place or time to another could result in large changes in resulting health effects due to O 3 formation and exposure. We indicate how the type of modeling carried out here might be used to attach externality-correcting prices to emissions. Charging emitters fees that are commensurate with the damage caused by their NO x emissions would create an incentive for emitters to reduce emissions at times and in locations where they cause the largest damage. (author)