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Sample records for accelerator-based radiation sources

  1. An accelerator-based epithermal photoneutron source for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Nigg, D.W.; Mitchell, H.E.; Harker, Y.D.; Yoon, W.Y. [and others

    1995-11-01

    Therapeutically-useful epithermal-neutron beams for BNCT are currently generated by nuclear reactors. Various accelerator-based neutron sources for BNCT have been proposed and some low intensity prototypes of such sources, generally featuring the use of proton beams and beryllium or lithium targets have been constructed. This paper describes an alternate approach to the realization of a clinically useful accelerator-based source of epithermal neutrons for BNCT that reconciles the often conflicting objectives of target cooling, neutron beam intensity, and neutron beam spectral purity via a two stage photoneutron production process.

  2. Laser wakefield accelerator based light sources: potential applications and requirements

    Energy Technology Data Exchange (ETDEWEB)

    Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). NIF and Photon Sciences; Thomas, A. G. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Mangles, S. P.D. [Imperial College, London (United Kingdom). Blackett Lab.; Banerjee, S. [Univ. of Nebraska, Lincoln, NE (United States); Corde, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Flacco, A. [ENSTA, CNRS, Ecole Polytechnique, Palaiseau (France); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Neely, D. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Viera, J. [Univ. of Lisbon (Portugal). GoLP-Inst. de Plasmas e Fusao Nuclear-Lab. Associado; Najmudin, Z. [Imperial College, London (United Kingdom). Blackett Lab.; Bingham, R. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Joshi, C. [Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Katsouleas, T. [Duke Univ., Durham, NC (United States). Platt School of Engineering

    2015-01-15

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  3. Applications of laser wakefield accelerator-based light sources

    Science.gov (United States)

    Albert, Félicie; Thomas, Alec G. R.

    2016-11-01

    Laser-wakefield accelerators (LWFAs) were proposed more than three decades ago, and while they promise to deliver compact, high energy particle accelerators, they will also provide the scientific community with novel light sources. In a LWFA, where an intense laser pulse focused onto a plasma forms an electromagnetic wave in its wake, electrons can be trapped and are now routinely accelerated to GeV energies. From terahertz radiation to gamma-rays, this article reviews light sources from relativistic electrons produced by LWFAs, and discusses their potential applications. Betatron motion, Compton scattering and undulators respectively produce x-rays or gamma-rays by oscillating relativistic electrons in the wakefield behind the laser pulse, a counter-propagating laser field, or a magnetic undulator. Other LWFA-based light sources include bremsstrahlung and terahertz radiation. We first evaluate the performance of each of these light sources, and compare them with more conventional approaches, including radio frequency accelerators or other laser-driven sources. We have then identified applications, which we discuss in details, in a broad range of fields: medical and biological applications, military, defense and industrial applications, and condensed matter and high energy density science.

  4. Observation of Neutron Skyshine from an Accelerator Based Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Franklyn, C. B. [Radiation Science Department, Necsa, PO Box 582, Pretoria 0001 (South Africa)

    2011-12-13

    A key feature of neutron based interrogation systems is the need for adequate provision of shielding around the facility. Accelerator facilities adapted for fast neutron generation are not necessarily suitably equipped to ensure complete containment of the vast quantity of neutrons generated, typically >10{sup 11} n{center_dot}s{sup -1}. Simulating the neutron leakage from a facility is not a simple exercise since the energy and directional distribution can only be approximated. Although adequate horizontal, planar shielding provision is made for a neutron generator facility, it is sometimes the case that vertical shielding is minimized, due to structural and economic constraints. It is further justified by assuming the atmosphere above a facility functions as an adequate radiation shield. It has become apparent that multiple neutron scattering within the atmosphere can result in a measurable dose of neutrons reaching ground level some distance from a facility, an effect commonly known as skyshine. This paper describes a neutron detection system developed to monitor neutrons detected several hundred metres from a neutron source due to the effect of skyshine.

  5. Lithium target for accelerator based BNCT neutron source: Influence by the proton irradiation on lithium

    Science.gov (United States)

    Fujii, R.; Imahori, Y.; Nakakmura, M.; Takada, M.; Kamada, S.; Hamano, T.; Hoshi, M.; Sato, H.; Itami, J.; Abe, Y.; Fuse, M.

    2012-12-01

    The neutron source for Boron Neutron Capture Therapy (BNCT) is in the transition stage from nuclear reactor to accelerator based neutron source. Generation of low energy neutron can be achieved by 7Li (p, n) 7Be reaction using accelerator based neutron source. Development of small-scale and safe neutron source is within reach. The melting point of lithium that is used for the target is low, and durability is questioned for an extended use at a high current proton beam. In order to test its durability, we have irradiated lithium with proton beam at the same level as the actual current density, and found no deterioration after 3 hours of continuous irradiation. As a result, it is suggested that lithium target can withstand proton irradiation at high current, confirming suitability as accelerator based neutron source for BNCT.

  6. An overview of an accelerator-based neutron spallation source

    Energy Technology Data Exchange (ETDEWEB)

    Lessner, E.S.

    1996-06-01

    An overview of the feasibility study of a 1-MW pulsed spallation source is presented. The machine delivers 1 MW of proton beam power to spallation targets where slow neutrons are produced. The slow neutrons can be used for isotope production, materials irradiation, and neutron scattering research. The neutron source facility is based on a rapid cycling synchrotron (RCS) and consists of a 400-MeV linac, a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV, and two neutron-generating target stations. The RCS accelerates an average proton beam current of 0.5 mA, corresponding to 1.04 x 10{sup 14} protons per pulse. This intensity is about two times higher than that of existing machines. A key feature of this accelerator system design is that beam losses are minimized from injection to extraction, reducing activation to levels consistent with hands-on maintenance.

  7. Lithium neutron producing target for BINP accelerator-based neutron source.

    Science.gov (United States)

    Bayanov, B; Belov, V; Kindyuk, V; Oparin, E; Taskaev, S

    2004-11-01

    Pilot innovative accelerator-based neutron source for neutron capture therapy is under construction now at the Budker Institute of Nuclear Physics, Novosibirsk, Russia. One of the main elements of the facility is lithium target, that produces neutrons via threshold (7)Li(p,n)(7)Be reaction at 25 kW proton beam with energies 1.915 or 2.5 MeV. In the present report, the results of experiments on neutron producing target prototype are presented, the results of calculations of hydraulic resistance for heat carrier flow and lithium layer temperature are shown. Calculation showed that the lithium target could run up to 10 mA proton beam before melting. Choice of target variant is substantiated. Program of immediate necessary experiments is described. Target design for neutron source constructed at BINP is presented. Manufacturing the neutron producing target up to the end of 2004 and obtaining a neutron beam on BINP accelerator-based neutron source are planned during 2005.

  8. Lithium neutron producing target for BINP accelerator-based neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Bayanov, B.; Belov, V.; Kindyuk, V.; Oparin, E.; Taskaev, S. E-mail: taskaev@inp.nsk.su

    2004-11-01

    Pilot innovative accelerator-based neutron source for neutron capture therapy is under construction now at the Budker Institute of Nuclear Physics, Novosibirsk, Russia. One of the main elements of the facility is lithium target, that produces neutrons via threshold {sup 7}Li(p,n){sup 7}Be reaction at 25 kW proton beam with energies 1.915 or 2.5 MeV. In the present report, the results of experiments on neutron producing target prototype are presented, the results of calculations of hydraulic resistance for heat carrier flow and lithium layer temperature are shown. Calculation showed that the lithium target could run up to 10 mA proton beam before melting. Choice of target variant is substantiated. Program of immediate necessary experiments is described. Target design for neutron source constructed at BINP is presented. Manufacturing the neutron producing target up to the end of 2004 and obtaining a neutron beam on BINP accelerator-based neutron source are planned during 2005.

  9. Characterisation of an accelerator-based neutron source for BNCT versus beam energy

    CERN Document Server

    Agosteo, S; D'Errico, F; Nath, R; Tinti, R

    2002-01-01

    Neutron capture in sup 1 sup 0 B produces energetic alpha particles that have a high linear energy transfer in tissue. This results in higher cell killing and a higher relative biological effectiveness compared to photons. Using suitably designed boron compounds which preferentially localize in cancerous cells instead of healthy tissues, boron neutron capture therapy (BNCT) has the potential of providing a higher tumor cure rate within minimal toxicity to normal tissues. This clinical approach requires a thermal neutron source, generally a nuclear reactor, with a fluence rate sufficient to deliver tumorcidal doses within a reasonable treatment time (minutes). Thermal neutrons do not penetrate deeply in tissue, therefore BNCT is limited to lesions which are either superficial or otherwise accessible. In this work, we investigate the feasibility of an accelerator-based thermal neutron source for the BNCT of skin melanomas. The source was designed via MCNP Monte Carlo simulations of the thermalization of a fast ...

  10. Conceptual design of an RFQ accelerator-based neutron source for boron neutron-capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wangler, T.P.; Stovall, J.E.; Bhatia, T.S.; Wang, C.K.; Blue, T.E.; Gahbauer, R.A.

    1989-01-01

    We present a conceptual design of a low-energy neutron generator for treatment of brain tumors by boron neutron capture theory (BNCT). The concept is based on a 2.5-MeV proton beam from a radio-frequency quadrupole (RFQ) linac, and the neutrons are produced by the /sup 7/Li(p,n)/sup 7/Be reaction. A liquid lithium target and modulator assembly are designed to provide a high flux of epithermal neutrons. The patient is administered a tumor-specific /sup 10/Be-enriched compound and is irradiated by the neutrons to create a highly localized dose from the reaction /sup 10/B(n,..cap alpha..)/sup 7/Li. An RFQ accelerator-based neutron source for BNCT is compact, which makes it practical to site the facility within a hospital. 11 refs., 5 figs., 1 tab.

  11. Characterisation of an accelerator-based neutron source for BNCT of explanted livers

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. [Politecnico di Milano (Italy). Dipartimento di Ingeneria Nucleare; Colautti, P. [INFN, Padova (Italy). Laboratori Nazionali di Legnaro; Corrado, M.G. [Universita degli Studi di Milano (Italy). Dipartimento di Fisica; d`Errico, F. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari; Matzke, M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Monti, S.; Tinti, R. [ENEA-ERG-FIRE, Bologna (Italy); Silari, M. [Consiglio Nazionale delle Ricerche, Milan (Italy)

    1997-09-01

    An accelerator-based thermal neutron source for BNCT of the explanted liver was designed using the MCNP code. Neutrons are generated via (d,n) reactions by 7 MeV deuterons bombarding a beryllium target. The therapy constraints were approached by simulating an irradiation cavity placed inside a graphite reflector parallelepiped containing a heavy-water moderator in turn enclosing the beryllium target. The experimental verification was performed at the Laboratori Nazionali di Legnaro (Italy). The thermal and epithermal neutron flux was measured at various positions in the irradiation cavity by means of activation techniques employing bare and cadmium covered indium foils. Further measurements were performed with BF{sub 3} detectors. The fast neutron component of the dose equivalent and the energy spectrum above 100keV were assessed by means of a recently developed technique employing variable threshold superheated drop detectors. The prompt gamma ray dose was measured with {sup 7}LiF TLDs. (author).

  12. Multipurpose applications of the accelerator-based neutron source[1pt] GENEPI2

    Science.gov (United States)

    Villa, F.; Baylac, M.; Billebaud, A.; Boge, P.; Cabanel, T.; Labussière, E.; Méplan, O.; Rey, S.

    2016-11-01

    GENEPI2 (GEnérateur de NEutrons Pulsé Intense) is an accelerator-based neutron source operating at LPSC laboratory in Grenoble (France). The neutrons are produced at 2.5MeV or 14.2MeV trough fusion reactions. GENEPI2 specifications allow performing efficiently accelerated irradiation tests of integrated circuits. This facility can also be operated to test and calibrate different types of detectors. This paper will describe the facility and its performances. Then, measurements of the neutron production will be presented as well as different types of experiments and irradiations. Finally, we describe upgrades undertaken to increase the neutron flux and optimize the facility for multiple applications.

  13. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, H.E.

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 10{sup 7} neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF{sub 3} composite and a stacked Al/Teflon design) at various incident electron energies.

  14. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Hannah E. [Georgia Inst. of Technology, Atlanta, GA (United States)

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 107 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF3 composite and a stacked Al/Teflon design) at various incident electron energies.

  15. Characterisation of an accelerator-based neutron source for BNCT versus beam energy

    Science.gov (United States)

    Agosteo, S.; Curzio, G.; d'Errico, F.; Nath, R.; Tinti, R.

    2002-01-01

    Neutron capture in 10B produces energetic alpha particles that have a high linear energy transfer in tissue. This results in higher cell killing and a higher relative biological effectiveness compared to photons. Using suitably designed boron compounds which preferentially localize in cancerous cells instead of healthy tissues, boron neutron capture therapy (BNCT) has the potential of providing a higher tumor cure rate within minimal toxicity to normal tissues. This clinical approach requires a thermal neutron source, generally a nuclear reactor, with a fluence rate sufficient to deliver tumorcidal doses within a reasonable treatment time (minutes). Thermal neutrons do not penetrate deeply in tissue, therefore BNCT is limited to lesions which are either superficial or otherwise accessible. In this work, we investigate the feasibility of an accelerator-based thermal neutron source for the BNCT of skin melanomas. The source was designed via MCNP Monte Carlo simulations of the thermalization of a fast neutron beam, generated by 7 MeV deuterons impinging on a thick target of beryllium. The neutron field was characterized at several deuteron energies (3.0-6.5 MeV) in an experimental structure installed at the Van De Graaff accelerator of the Laboratori Nazionali di Legnaro, in Italy. Thermal and epithermal neutron fluences were measured with activation techniques and fast neutron spectra were determined with superheated drop detectors (SDD). These neutron spectrometry and dosimetry studies indicated that the fast neutron dose is unacceptably high in the current design. Modifications to the current design to overcome this problem are presented.

  16. Prospect for application of compact accelerator-based neutron source to neutron engineering diffraction

    Science.gov (United States)

    Ikeda, Yoshimasa; Taketani, Atsushi; Takamura, Masato; Sunaga, Hideyuki; Kumagai, Masayoshi; Oba, Yojiro; Otake, Yoshie; Suzuki, Hiroshi

    2016-10-01

    A compact accelerator-based neutron source has been lately discussed on engineering applications such as transmission imaging and small angle scattering as well as reflectometry. However, nobody considers using it for neutron diffraction experiment because of its low neutron flux. In this study, therefore, the neutron diffraction experiments are carried out using Riken Accelerator-driven Compact Neutron Source (RANS), to clarify the capability of the compact neutron source for neutron engineering diffraction. The diffraction pattern from a ferritic steel was successfully measured by suitable arrangement of the optical system to reduce the background noise, and it was confirmed that the recognizable diffraction pattern can be measured by a large sampling volume with 10 mm in cubic for an acceptable measurement time, i.e. 10 min. The minimum resolution of the 110 reflection for RANS is approximately 2.5% at 8 μs of the proton pulse width, which is insufficient to perform the strain measurement by neutron diffraction. The moderation time width at the wavelength corresponding to the 110 reflection is estimated to be approximately 30 μs, which is the most dominant factor to determine the resolution. Therefore, refinements of the moderator system to decrease the moderation time by decreasing a thickness of the moderator or by applying the decoupler system or application of the angular dispersive neutron diffraction technique are important to improve the resolution of the diffraction experiment using the compact neutron source. In contrast, the texture evolution due to plastic deformation was successfully observed by measuring a change in the diffraction peak intensity by RANS. Furthermore, the volume fraction of the austenitic phase in the dual phase mock specimen was also successfully evaluated by fitting the diffraction pattern using a Rietveld code. Consequently, RANS has been proved to be capable for neutron engineering diffraction aiming for the easy access

  17. Characterisation of an accelerator-based neutron source for BNCT versus beam energy

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. E-mail: stefano.agosteo@polimi.it; Curzio, G.; D' Errico, F.; Nath, R.; Tinti, R

    2002-01-01

    Neutron capture in {sup 10}B produces energetic alpha particles that have a high linear energy transfer in tissue. This results in higher cell killing and a higher relative biological effectiveness compared to photons. Using suitably designed boron compounds which preferentially localize in cancerous cells instead of healthy tissues, boron neutron capture therapy (BNCT) has the potential of providing a higher tumor cure rate within minimal toxicity to normal tissues. This clinical approach requires a thermal neutron source, generally a nuclear reactor, with a fluence rate sufficient to deliver tumorcidal doses within a reasonable treatment time (minutes). Thermal neutrons do not penetrate deeply in tissue, therefore BNCT is limited to lesions which are either superficial or otherwise accessible. In this work, we investigate the feasibility of an accelerator-based thermal neutron source for the BNCT of skin melanomas. The source was designed via MCNP Monte Carlo simulations of the thermalization of a fast neutron beam, generated by 7 MeV deuterons impinging on a thick target of beryllium. The neutron field was characterized at several deuteron energies (3.0-6.5 MeV) in an experimental structure installed at the Van De Graaff accelerator of the Laboratori Nazionali di Legnaro, in Italy. Thermal and epithermal neutron fluences were measured with activation techniques and fast neutron spectra were determined with superheated drop detectors (SDD). These neutron spectrometry and dosimetry studies indicated that the fast neutron dose is unacceptably high in the current design. Modifications to the current design to overcome this problem are presented.

  18. Accelerator-based epithermal neutron sources for boron neutron capture therapy of brain tumors.

    Science.gov (United States)

    Blue, Thomas E; Yanch, Jacquelyn C

    2003-01-01

    This paper reviews the development of low-energy light ion accelerator-based neutron sources (ABNSs) for the treatment of brain tumors through an intact scalp and skull using boron neutron capture therapy (BNCT). A major advantage of an ABNS for BNCT over reactor-based neutron sources is the potential for siting within a hospital. Consequently, light-ion accelerators that are injectors to larger machines in high-energy physics facilities are not considered. An ABNS for BNCT is composed of: (1) the accelerator hardware for producing a high current charged particle beam, (2) an appropriate neutron-producing target and target heat removal system (HRS), and (3) a moderator/reflector assembly to render the flux energy spectrum of neutrons produced in the target suitable for patient irradiation. As a consequence of the efforts of researchers throughout the world, progress has been made on the design, manufacture, and testing of these three major components. Although an ABNS facility has not yet been built that has optimally assembled these three components, the feasibility of clinically useful ABNSs has been clearly established. Both electrostatic and radio frequency linear accelerators of reasonable cost (approximately 1.5 M dollars) appear to be capable of producing charged particle beams, with combinations of accelerated particle energy (a few MeV) and beam currents (approximately 10 mA) that are suitable for a hospital-based ABNS for BNCT. The specific accelerator performance requirements depend upon the charged particle reaction by which neutrons are produced in the target and the clinical requirements for neutron field quality and intensity. The accelerator performance requirements are more demanding for beryllium than for lithium as a target. However, beryllium targets are more easily cooled. The accelerator performance requirements are also more demanding for greater neutron field quality and intensity. Target HRSs that are based on submerged-jet impingement and

  19. PREFACE: 6th Workshop on Infrared Spectroscopy and Microscopy with Accelerator-Based Sources (WIRMS11)

    Science.gov (United States)

    Lupi, Stefano; Perucchi, Andrea

    2012-05-01

    This volume of Journal of Physics: Conference Series is dedicated to a subset of papers related to the work presented at the 6th edition of the international Workshop on Infrared Spectroscopy and Microscopy with Accelerator-Based Sources (WIRMS), held in Trieste, Italy, September 4-8 2011. Previous editions of the conference were held in Porquerolles (France), Lake Tahoe (USA), Rathen (Germany), Awaji (Japan), and Banff (Canada). This edition was organized and chaired by Stefano Lupi (Roma La Sapienza) and co-chaired by Andrea Perucchi (Elettra), with the support of the Italian Synchrotron Light Laboratory ELETTRA, which was honored to host the WIRMS workshop in its tenth anniversary. The 6th WIRMS edition addressed several different topics, ranging from biochemistry to strongly correlated materials, from geology to conservation science, and from forensics to the study of cometary dusts. Representatives from the infrared scientific programs at synchrotron light sources and free-electron-laser facilities. This edition was attended by 88 participants, including representatives from the infrared scientific programs at synchrotron light sources and free-electron-laser facilities, who enjoyed the stimulating scientific presentations, several detailed discussions, and the beautiful weather and scenery of the Trieste gulf. Participants came from 16 different nations and four continents, including many young scientists, six of which were supported by the organizers. There were 45 scientific talks divided in 11 sessions: Facilities, Microspectroscopy (I, II, III), Time-Resolved Spectroscopies, Extreme Conditions, Condensed Matter, Near-Field, Imaging, THz Techniques and High-Resolution Spectroscopy. 37 posters were also presented at two very lively evening poster sessions. We would like to use the opportunity of writing this preface to thank all the participants of the workshop for the very high level of their scientific contribution and for the very friendly atmosphere

  20. Complications following linear accelerator based stereotactic radiation for cerebral arteriovenous malformations

    DEFF Research Database (Denmark)

    Skjøth-Rasmussen, Jane; Roed, Henrik; Ohlhues, Lars;

    2010-01-01

    Primarily, gamma knife centers are predominant in publishing results on arteriovenous malformations (AVM) treatments including reports on risk profile. However, many patients are treated using a linear accelerator-most of these at smaller centers. Because this setting is different from a large...... gamma knife center, the risk profile at Linac departments could be different from the reported experience. Prescribed radiation doses are dependent on AVM volume. This study details results from a medium sized Linac department center focusing on risk profiles....

  1. Cherenkov radiation in a surface wave accelerator based on silicon carbide

    Science.gov (United States)

    Wang, Tianhong; Khudik, Vladimir; Shvets, Gennady

    2016-10-01

    We report on our theoretical investigations of Cherenkov-type emission of surface phonon polaritons (SPPs) by relativistic electron bunches. The polaritons are confined by a planar waveguide comprised of two SiC slabs separated by an air gap. The SPPs are generated in the spectral range known as the reststrahlen band, where the dielectric permittivity of SiC is negative. Two surface modes of the radiation are analyzed: the longitudinal (accelerating) and the transverse (deflecting) ones. Both form Cherenkov cones that are different in the magnitude of the cone angle and the central frequency. However, both exhibits rapid spatial oscillations and beats behind the moving charge. Moreover, the longitudinal mode forms a reversed Cherenkov radiation cone due the negative group velocity for sufficiently small air gaps, but the transverse mode does not. The wakefield acceleration of electron beam inside the structure is also studied. Transverse instabilities and BBU effects can be suppressed by flat driver beam, meanwhile the longitudinal mode can support accelerating fields >1 GeV.

  2. 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.

  3. Optimization of an accelerator-based epithermal neutron source for neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kononov, O.E.; Kononov, V.N.; Bokhovko, M.V.; Korobeynikov, V.V.; Soloviev, A.N.; Chu, W.T.

    2004-02-20

    A modeling investigation was performed to choose moderator material and size for creating optimal epithermal neutron beams for BNCT based on a proton accelerator and the 7Li(p,n)7Be reaction as a neutrons source. An optimal configuration is suggested for the beam shaping assembly made from polytetrafluoroethylene and magnesium fluorine. Results of calculation were experimentally tested and are in good agreement with measurements.

  4. Frequency mixing in accelerator based sources and application to tunable seeded free-electron lasers

    Directory of Open Access Journals (Sweden)

    C. Evain

    2014-12-01

    Full Text Available In this article we address the problem of tunability of seeded free-electron lasers (FELs, working typically in the domain of the vacuum ultraviolet. The seeding of FELs with an external laser permits us to obtain FEL pulses with both good longitudinal coherence and good stability properties (contrary to an amplification starting from noise. However, with a fixed external laser wavelength, only amplification at harmonics of this wavelength is possible. If full tunability is wanted, it is necessary to have a tunable external source; but this type of source has much less power, hence it is much harder to reach high harmonics numbers. Here we propose the so-called frequency mixing scheme (from its analogy with the similar process in nonlinear optics, based on two laser/electron interactions. Numerical and analytic studies show that it permits to increase significantly the tunability at short wavelengths using a low-energy tunable source. Numerical simulations are made with the parameters of FERMI-FEL 1, the first seeded FEL for user operation.

  5. 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.

  6. 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.

  7. 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...

  8. Development of high intensity ion sources for a Tandem-Electrostatic-Quadrupole facility for Accelerator-Based Boron Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bergueiro, J. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Buenos Aires (Argentina); Igarzabal, M.; Suarez Sandin, J.C. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina); Somacal, H.R. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Thatar Vento, V. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [CONICET, Buenos Aires (Argentina); Huck, H.; Valda, A.A. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Repetto, M. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica (Argentina)

    2011-12-15

    Several ion sources have been developed and an ion source test stand has been mounted for the first stage of a Tandem-Electrostatic-Quadrupole facility For Accelerator-Based Boron Neutron Capture Therapy. A first source, designed, fabricated and tested is a dual chamber, filament driven and magnetically compressed volume plasma proton ion source. A 4 mA beam has been accelerated and transported into the suppressed Faraday cup. Extensive simulations of the sources have been performed using both 2D and 3D self-consistent codes.

  9. Tissue equivalent proportional counter microdosimetry measurements utililzed aboard aircraft and in accelerator based space radiation shielding studies

    Science.gov (United States)

    Gersey, Brad; Wilkins, Richard

    The space radiation environment presents a potential hazard to the humans, electronics and materials that are exposed to it. Particle accelerator facilities such as the NASA Space Ra-diation Laboratory (NSRL) and Loma Linda University Medical Center (LLUMC) provide particle radiation of specie and energy within the range of that found in the space radiation environment. Experiments performed at these facilities determine various endpoints for bio-logical, electronic and materials exposures. A critical factor in the performance of rigorous scientific studies of this type is accurate dosimetric measurements of the exposures. A Tissue Equivalent Proportional Counter (TEPC) is a microdosimeter that may be used to measure absorbed dose, average quality factor (Q) and dose equivalent of the particle beam utilized in these experiments. In this work, results from a variety of space radiation shielding studies where a TEPC was used to perform dosimetry in the particle beam will be presented. These results compare the absorbed dose and dose equivalent measured downstream of equal density thicknesses of stan-dard and multifunctional shielding materials. The standard materials chosen for these shielding studies included High-Density Polyethylene (HDPE) and aluminum alloy, while the multifunc-tional materials included carbon composite infused with single walled carbon nanotubes. High energy particles including proton, silicon and iron nuclei were chosen as the incident radia-tion for these studies. Further, TEPC results from measurements taken during flights aboard ER-2 and KC-135 aircraft will also be discussed. Results from these flight studies include TEPC measurements for shielded and unshielded conditions as well as the effect of vibration and electromagnetic exposures on the TEPC operation. The data selected for presentation will highlight the utility of the TEPC in space radiation studies, and in shielding studies in particular. The lineal energy response function of the

  10. Demonstration of a high-intensity neutron source based on a liquid-lithium target for Accelerator based Boron Neutron Capture Therapy.

    Science.gov (United States)

    Halfon, S; Arenshtam, A; Kijel, D; Paul, M; Weissman, L; Berkovits, D; Eliyahu, I; Feinberg, G; Kreisel, A; Mardor, I; Shimel, G; Shor, A; Silverman, I; Tessler, M

    2015-12-01

    A free surface liquid-lithium jet target is operating routinely at Soreq Applied Research Accelerator Facility (SARAF), bombarded with a ~1.91 MeV, ~1.2 mA continuous-wave narrow proton beam. The experiments demonstrate the liquid lithium target (LiLiT) capability to constitute an intense source of epithermal neutrons, for Accelerator based Boron Neutron Capture Therapy (BNCT). The target dissipates extremely high ion beam power densities (>3 kW/cm(2), >0.5 MW/cm(3)) for long periods of time, while maintaining stable conditions and localized residual activity. LiLiT generates ~3×10(10) n/s, which is more than one order of magnitude larger than conventional (7)Li(p,n)-based near threshold neutron sources. A shield and moderator assembly for BNCT, with LiLiT irradiated with protons at 1.91 MeV, was designed based on Monte Carlo (MCNP) simulations of BNCT-doses produced in a phantom. According to these simulations it was found that a ~15 mA near threshold proton current will apply the therapeutic doses in ~1h treatment duration. According to our present results, such high current beams can be dissipated in a liquid-lithium target, hence the target design is readily applicable for accelerator-based BNCT.

  11. On accelerator-based neutron sources and neutron field characterization with low energy neutron spectrometer based on position sensitive 3He counter.

    Science.gov (United States)

    Murata, I; Miyamaru, H; Kato, I; Mori, Y

    2009-07-01

    The development of new neutron sources for BNCT applications, based on particle accelerators is currently underway all over the world. Though nuclear reactors were used for a long time as the only neutron source available having the requested flux levels, the accelerator-based ones have recently been investigated on the other hand due to its easy-to-use and acceptable performances. However, when using an accelerator, various secondary particles would be emitted which forms a troublesome background. Moreover, the neutrons produced have usually an energy spectrum somewhat different from the requested one and thus should be largely moderated. An additional issue to be taken into account is the patient positioning, which should be close to the neutron source, in order to take advantage of a neutron flux level high enough to limit the BNCT treatment time within 1h. This implies that, inside a relatively narrow space, neutrons should be moderated, while unnecessary secondary particles should be shielded. Considering that a background-free neutron field from an accelerator-driven neutron source dedicated to BNCT application is generally difficult to be provided, the characterization of such a neutron field will have to be clearly assessed. In the present study, a low energy neutron spectrometer has been thus designed and is now being developed to measure the accelerator-based neutron source performance. The presently proposed spectrometer is based on a (3)He proportional counter, which is 50 cm long and 5 cm in diameter, with a gas pressure of 0.5 MPa. It is quite unique that the spectrometer is set up in parallel with the incident neutron beam and a reaction depth distribution is measured by it as a position sensitive detector. Recently, a prototype detector has been developed and the signal test is now underway. In this paper, the feature of the accelerator-based neutron sources is outlined and importance of neutron field characterization is discussed. And the developed

  12. 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.

  13. Neutron spectral fluence measurements using a Bonner sphere spectrometer in the development of the iBNCT accelerator-based neutron source.

    Science.gov (United States)

    Masuda, Akihiko; Matsumoto, Tetsuro; Takada, Kenta; Onishi, Takahiro; Kotaki, Kohei; Sugimoto, Hidenori; Kumada, Hiroaki; Harano, Hideki; Sakae, Takeji

    2017-09-01

    The neutron spectral fluence of an accelerator-based neutron source facility for boron neutron capture therapy (BNCT) based on a proton linac and a beryllium target was evaluated by the unfolding method using a Bonner sphere spectrometer (BSS). A (3)He-proportional-counter-based BSS was used with weak beam during the development of the facility. The measured epithermal neutron spectra were consistent with calculations. The epithermal neutron intensity at the beam port was estimated and the results gave a numerical target for the enhancement of the proton beam intensity and will be used as reference data for measurements performed after the completion of the facility. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Capillary Discharge XUV Radiation Source

    Directory of Open Access Journals (Sweden)

    M. Nevrkla

    2009-01-01

    Full Text Available A device producing Z-pinching plasma as a source of XUV radiation is described. Here a ceramic capacitor bank pulse-charged up to 100 kV is discharged through a pre-ionized gas-filled ceramic tube 3.2 mm in diameter and 21 cm in length. The discharge current has amplitude of 20 kA and a rise-time of 65 ns. The apparatus will serve as experimental device for studying of capillary discharge plasma, for testing X-ray optics elements and for investigating the interaction of water-window radiation with biological samples. After optimization it will be able to produce 46.9 nm laser radiation with collision pumped Ne-like argon ions active medium. 

  15. Thermal Radiation Source Test Facility,

    Science.gov (United States)

    1984-01-01

    KEY WORDS (Continu on revers side I eesr and identify by block nuMb.,) Thermal Radiation Source Thermal Test Facility 20 ABSTRACT (Continue on reverse...SECTION 1 INTRODUCTION 1-1 GENERAL Defense Nuclear Agency’s Field Command, located at Kirtland AFB in New Mexico, has recently upgraded its thermal test facility...is used to evaluate damage and survivability in a nuclear environment. The thermal test facility was first established in 1979 and used O large

  16. Doses from Medical Radiation Sources

    Science.gov (United States)

    ... Memoriam Sections All Sections (listing) Accelerator AIRRS Decommissioning Environmental/Radon Homeland Security Instrumentation Medical Health Physics Military Health Physics Nonionizing Radiation Power Reactor Affiliates ...

  17. 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.

  18. 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 med......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...

  19. Edge radiation as IR-UV source

    CERN Document Server

    Shirasawa, K; Hiraya, A; Muneyoshi, T

    2003-01-01

    Edge radiation, generated by a high-energy electron beam in fringe fields of storage ring bending magnets, has good potentials to be used as a source of radiation in infrared-ultraviolet spectral range. Spatial distributions of horizontally and vertically polarized components of edge radiation in a near ultraviolet, visible and near infrared regions were experimentally measured at HiSOR storage ring (Hiroshima, Japan). It is shown experimentally that edge radiation intensity in this spectral range is higher than that of a standard synchrotron radiation. For theoretical analysis, the new package of computer codes was written. A good agreement with numerical simulations is found.

  20. Electrodeless microwave source of UV radiation

    Science.gov (United States)

    Barkhudarov, E. M.; Kozlov, Yu. N.; Kossyi, I. A.; Malykh, N. I.; Misakyan, M. A.; Taktakishvili, I. M.; Khomichenko, A. A.

    2012-06-01

    The parameters of an electrodeless microwave low-pressure discharge in an Ar + Hg vapor mixture are studied, the design of a UV radiation source for water disinfection is suggested, and its main characteristics are presented. The domestic microwave oven ( f = 2.45 GHz; N = kW) is used as a microwave radiation source. The maximal UV power at wavelength λ = 254 nm amounts to 120-130 W.

  1. Dosimetric Comparison of Real-Time MRI-Guided Tri-Cobalt-60 Versus Linear Accelerator-Based Stereotactic Body Radiation Therapy Lung Cancer Plans.

    Science.gov (United States)

    Wojcieszynski, Andrzej P; Hill, Patrick M; Rosenberg, Stephen A; Hullett, Craig R; Labby, Zacariah E; Paliwal, Bhudatt; Geurts, Mark W; Bayliss, R Adam; Bayouth, John E; Harari, Paul M; Bassetti, Michael F; Baschnagel, Andrew M

    2017-06-01

    Magnetic resonance imaging-guided radiation therapy has entered clinical practice at several major treatment centers. Treatment of early-stage non-small cell lung cancer with stereotactic body radiation therapy is one potential application of this modality, as some form of respiratory motion management is important to address. We hypothesize that magnetic resonance imaging-guided tri-cobalt-60 radiation therapy can be used to generate clinically acceptable stereotactic body radiation therapy treatment plans. Here, we report on a dosimetric comparison between magnetic resonance imaging-guided radiation therapy plans and internal target volume-based plans utilizing volumetric-modulated arc therapy. Ten patients with early-stage non-small cell lung cancer who underwent radiation therapy planning and treatment were studied. Following 4-dimensional computed tomography, patient images were used to generate clinically deliverable plans. For volumetric-modulated arc therapy plans, the planning tumor volume was defined as an internal target volume + 0.5 cm. For magnetic resonance imaging-guided plans, a single mid-inspiratory cycle was used to define a gross tumor volume, then expanded 0.3 cm to the planning tumor volume. Treatment plan parameters were compared. Planning tumor volumes trended larger for volumetric-modulated arc therapy-based plans, with a mean planning tumor volume of 47.4 mL versus 24.8 mL for magnetic resonance imaging-guided plans ( P = .08). Clinically acceptable plans were achievable via both methods, with bilateral lung V20, 3.9% versus 4.8% ( P = .62). The volume of chest wall receiving greater than 30 Gy was also similar, 22.1 versus 19.8 mL ( P = .78), as were all other parameters commonly used for lung stereotactic body radiation therapy. The ratio of the 50% isodose volume to planning tumor volume was lower in volumetric-modulated arc therapy plans, 4.19 versus 10.0 ( P plans, 1.25 versus 1.25 ( P = .98). Magnetic resonance imaging-guided tri

  2. Treatment Planning for Accelerator-Based Boron Neutron Capture Therapy

    Science.gov (United States)

    Herrera, María S.; González, Sara J.; Minsky, Daniel M.; Kreiner, Andrés J.

    2010-08-01

    Glioblastoma multiforme and metastatic melanoma are frequent brain tumors in adults and presently still incurable diseases. Boron Neutron Capture Therapy (BNCT) is a promising alternative for this kind of pathologies. Accelerators have been proposed for BNCT as a way to circumvent the problem of siting reactors in hospitals and for their relative simplicity and lower cost among other advantages. Considerable effort is going into the development of accelerator-based BNCT neutron sources in Argentina. Epithermal neutron beams will be produced through appropriate proton-induced nuclear reactions and optimized beam shaping assemblies. Using these sources, computational dose distributions were evaluated in a real patient with diagnosed glioblastoma treated with BNCT. The simulated irradiation was delivered in order to optimize dose to the tumors within the normal tissue constraints. Using Monte Carlo radiation transport calculations, dose distributions were generated for brain, skin and tumor. Also, the dosimetry was studied by computing cumulative dose-volume histograms for volumes of interest. The results suggest acceptable skin average dose and a significant dose delivered to tumor with low average whole brain dose for irradiation times less than 60 minutes, indicating a good performance of an accelerator-based BNCT treatment.

  3. Gravitational radiation sources and signatures

    CERN Document Server

    Finn, L S

    2001-01-01

    The goal of these lecture notes is to introduce the developing research area of gravitational-wave phenomenology. In more concrete terms, they are meant to provide an overview of gravitational-wave sources and an introduction to the interpretation of real gravitational wave detector data. They are, of course, limited in both regards. Either topic could be the subject of one or more books, and certainly more than the few lectures possible in a summer school. Nevertheless, it is possible to talk about the problems of data analysis and give something of their flavor, and do the same for gravitational wave sources that might be observed in the upcoming generation of sensitive detectors. These notes are an attempt to do just that.

  4. Characterization of coherent Cherenkov radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.V.

    2015-01-21

    Engineering formulae for calculation of peak, and spectral brightness of resonant long-range wakefield extractor are given. It is shown that the brightness is dominated by beam density in the slow wave structure and antenna gain of the outcoupling. Far field radiation patterns and brightness of circular and high aspect ratio planar radiators are compared. A possibility to approach diffraction limited brightness is demonstrated. The role of group velocity in designing of the Cherenkov source is analyzed. The approach can be applied for design and characterization of various structure-dominated sources (e.g., wakefield extractors with gratings or dielectrics, or FEL-Cherenkov combined sources) radiating into a free space using an antenna (in microwave to sub-mm wave regions). The high group velocity structures can be also effective as energy dechirpers and for diagnostics of microbunched relativistic electron beams.

  5. Maximum Likelihood Localization of Radiation Sources with unknown Source Intensity

    CERN Document Server

    Baidoo-Williams, Henry E

    2016-01-01

    In this paper, we consider a novel and robust maximum likelihood approach to localizing radiation sources with unknown statistics of the source signal strength. The result utilizes the smallest number of sensors required theoretically to localize the source. It is shown, that should the source lie in the open convex hull of the sensors, precisely $N+1$ are required in $\\mathbb{R}^N, ~N \\in \\{1,\\cdots,3\\}$. It is further shown that the region of interest, the open convex hull of the sensors, is entirely devoid of false stationary points. An augmented gradient ascent algorithm with random projections should an estimate escape the convex hull is presented.

  6. 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

  7. Underdense radiation sources: Moving towards longer wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Back, C.A.; Kilkenny, J.D. [General Atomics, San Diego, California (United States); Seely, J.F.; Weaver, J.L. [Naval Research Laboratory, Washington, DC (United States); Feldman, U. [Artep Inc., Ellicott City, MD (United States); Tommasini, R.; Glendinning, S.G.; Chung, H.K.; Rosen, M.; Lee, R.W.; Scott, H.A. [Lawrence Livermore National Laboratory, California (United States); Tillack, M. [U. C. San Diego, La Jolla, CA (United States)

    2006-06-15

    Underdense radiation sources have been developed to provide efficient laboratory multi-keV radiation sources for radiography and radiation hardening studies. In these plasmas laser absorption by inverse Bremsstrahlung leads to high x-ray conversion efficiency because of efficient ionization of the low density aerogel or gas targets. Now we performing experiments in the soft x-ray energy regime where the atomic physics models are much more complicated. In recent experiments at the NIKE laser, we have irradiated a Ti-doped SiO{sub 2} aerogel with up to 1650 J of 248 nm wavelength light. The absolute Ti L-shell emission in the 200-800 eV range is measured with a diagnostic that uses a transmission grating coupled to Si photodiodes. We will give an overview of the temporally-resolved absolutely calibrated spectra obtained over a range of conditions. (authors)

  8. Laboratory source of synchrotron radiation: TROLL-2

    Science.gov (United States)

    Anevsky, S. I.; Vernyi, A. E.; Panasjuk, V. S.; Khromchenko, V. B.

    1987-11-01

    A laboratory synchrotron radiation (SR) source TROLL-2 is described. Its main parameters are as follows: the energy of the accelerated particles = 24 MeV; the orbit radius = 20 mm; the SR pulse half-width = 2 ms, the maximum spectral radiant power (at λ = 350 nm) = 1.2×10 6 W/m.

  9. Network algorithms for detection of radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Nageswara S.V.; Sen, Satyabrata; Prins, Nicholas J. [Computer Science and Mathematics Div, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Cooper, Daniel A.; Ledoux, Robert J.; Costales, James B.; Kamieniecki, Krzysztof; Korbly, Steven E.; Thompson, Jeffrey K.; Batcheler, James [Passport Systems Inc., N. Billerica, MA 01862 (United States); Brooks, Richard R. [Department of Electrical and Computer Engineering, Clemson University, Clemson, SC 29634 (United States); Wu, Chase Q. [Department of Computer Science, University of Memphis, Memphis, TN 38152 (United States)

    2015-06-01

    Networks of radiation counters have been recently developed for detecting low-level, hazardous radiation sources, and they have been utilized in indoor and outdoor characterization tests. Subsequently, the test measurements have been “replayed” using multiple sub-networks, which enabled the analysis of various scenarios beyond the tests. We present a particle filter algorithm that combines measurements from gamma counters across the network to detect radiation sources. Using replays from an outdoor test, we construct a border monitoring scenario that consists of twelve 2 in.×2 in. NaI detectors or counters deployed on the periphery to monitor a 42×42 m{sup 2} region. A {sup 137}Cs source is moved across this region, starting several meters outside and finally moving away from it. The measurements from individual, pairs and boundary detectors are replayed using the particle filter algorithm. The algorithm outputs demonstrate, both quantitatively and qualitatively, the benefits of networking all boundary counters: the source is detected meters before it enters the region, while being inside, and until moving several meters away. On the other hand, when counters are used individually or in pairs, the source is detected for much shorter durations, and sometimes not detected at all while inside the region.

  10. Source of broadband Jovian Kilometric radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.; Leblanc, Y.

    1987-02-01

    Broadband Jovian Kilometric radiation was observed by Voyagers 1 and 2 to be beamed away from the zenomagnetic equatorial plane. Two theories were proposed for the equatorial shadow zone. One suggested that Io plasma torus forms an obstacle to radiation produced on auroral field lines. The other theory proposed that the source is located on the outer flanks of the torus, the beaming being inherent to the emission mechanism. Results are presented which indicate that the latter is consistent with the observations and it would appear that the emission is produced by linear mode conversion of electrostatic upper hybrid to electromagnetic waves in plasma density gradients.

  11. 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.

  12. Preliminary design report of a relativistic-Klystron two-beam-accelerator based power source for a 1 TeV center-of-mass next linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Goffeney, N.; Henestroza, E. [Lawrence Berkeley Lab., CA (United States)] [and others

    1995-02-22

    A preliminary point design for an 11.4 GHz power source for a 1 TeV center-of-mass Next Linear Collider (NLC) based on the Relativistic-Klystron Two-Beam-Accelerator (RK-TBA) concept is presented. The present report is the result of a joint LBL-LLNL systems study. consisting of three major thrust areas: physics, engineering, and costing. The new RK-TBA point design, together with our findings in each of these areas, are reported.

  13. Plasma wake field XUV radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Prono, Daniel S. (Los Alamos, NM); Jones, Michael E. (Los Alamos, NM)

    1997-01-01

    A XUV radiation source uses an interaction of electron beam pulses with a gas to create a plasma radiator. A flowing gas system (10) defines a circulation loop (12) with a device (14), such as a high pressure pump or the like, for circulating the gas. A nozzle or jet (16) produces a sonic atmospheric pressure flow and increases the density of the gas for interacting with an electron beam. An electron beam is formed by a conventional radio frequency (rf) accelerator (26) and electron pulses are conventionally formed by a beam buncher (28). The rf energy is thus converted to electron beam energy, the beam energy is used to create and then thermalize an atmospheric density flowing gas to a fully ionized plasma by interaction of beam pulses with the plasma wake field, and the energetic plasma then loses energy by line radiation at XUV wavelengths Collection and focusing optics (18) are used to collect XUV radiation emitted as line radiation when the high energy density plasma loses energy that was transferred from the electron beam pulses to the plasma.

  14. Radiation Safety of Sealed Radioactive Sources

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, Kathryn H.

    2015-01-01

    Sealed radioactive sources are used in a wide variety of occupational settings and under differing regulatory/licensing structures. The definition of a sealed radioactive source varies between US regulatory authorities and standard-setting organizations. Potential problems with sealed sources cover a range of risks and impacts. The loss of control of high activity sealed sources can result in very high or even fatal doses to members of the public who come in contact with them. Sources that are not adequately sealed, and that fail, can cause spread of contamination and potential intake of radioactive material. There is also the possibility that sealed sources may be (or threatened to be) used for terrorist purposes and disruptive opportunities. Until fairly recently, generally-licensed sealed sources and devices received little, if any, regulatory oversight, and were often forgotten, lost or unaccounted for. Nonetheless, generally licensed devices can contain fairly significant quantities of radioactive material and there is some potential for exposure if a device is treated in a way that it was never designed. Industrial radiographers use and handle high activity and/or high-dose rate sealed sources in the field with a high degree of independence and minimal regulatory oversight. Failure to follow operational procedures and properly handle radiography sources can and has resulted in serious injuries and death. Industrial radiographers have experienced a disproportionately large fraction of incidents that result in unintended exposure to radiation. Sources do not have to contain significant quantities of radioactive material to cause problems in the event of their failure. A loss of integrity can cause the spread of contamination and potential exposure to workers and members of the public. The NCRP has previously provided recommendations on select aspects of sealed source programs. Future efforts to provide recommendations for sealed source programs are discussed.

  15. Accelerator-based neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Deborah A.; /Fermilab

    2007-12-01

    Neutrino oscillations were first discovered by experiments looking at neutrinos coming from extra-terrestrial sources, namely the sun and the atmosphere, but we will be depending on earth-based sources to take many of the next steps in this field. This article describes what has been learned so far from accelerator-based neutrino oscillation experiments, and then describe very generally what the next accelerator-based steps are. In section 2 the article discusses how one uses an accelerator to make a neutrino beam, in particular, one made from decays in flight of charged pions. There are several different neutrino detection methods currently in use, or under development. In section 3 these are presented, with a description of the general concept, an example of such a detector, and then a brief discussion of the outstanding issues associated with this detection technique. Finally, section 4 describes how the measurements of oscillation probabilities are made. This includes a description of the near detector technique and how it can be used to make the most precise measurements of neutrino oscillations.

  16. [Radiation safety of exploitation of radiation sources at the civil aviation airlines].

    Science.gov (United States)

    Afanas'ev, R V; Zuev, V G; Berezin, G I; Sereda, V N; Zasiad'ko, A K

    2004-01-01

    Radiation risks from isotope-containing equipment, and ionizing and unused X-ray radiation sources are characterized and relevant normative documents with safety requirements to radiation sources installation, radiation safety of aircraft servicing and repair, hand luggage control and heavy luggage registration, personal protection items, system of radiation monitoring at airlines and aircraft works, and liability for breach of performance guidelines are cited.

  17. Accelerator-based validation of shielding codes

    OpenAIRE

    Zeitlin, Cary; Heilbronn, Lawrence; Miller, Jack; Wilson, John W.

    2002-01-01

    The space radiation environment poses risks to astronaut health from a diverse set of sources, ranging from low-energy protons and electrons to highly-charged, high-energy atomic nuclei and their associated fragmentation products, including neutrons. The low-energy protons and electrons are the source of most of the radiation dose to Shuttle and ISS crews, while the more energetic particles that comprise the Galactic Cosmic Radiation (protons, He, and heavier nuclei up to Fe) will be th...

  18. Development of Reactor RIs and Radiation Sources

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ul Jae; Han, H. S.; Lee, J. S. [KAERI, Daejeon (Korea, Republic of); and others

    2010-04-15

    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. {center_dot} 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 {sup 177}Lu and developed production processes for {sup 147}Pm and {sup 47}Sc {center_dot} Demonstration of {sup 188}W/{sup 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 {center_dot} Development of {sup 90}Sr/{sup 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 {sup 90}Y : 100 {approx} 10,000 purer than commercially available products - Constructed pilot scale generator system for regular production of {sup 90}Y {center_dot}Development of {beta}-ray sources for thickness measurements and brachytherapy - Developed {sup 90}Sr thickness gauge source and received KOLAS certification - Developed and tested for the possibility of the application of a {beta}-ray source to brachytherapy of eye diseases. - Completed safety accessment of the P-32brachytherapy source {center_dot}Development of Small Focal {gamma}-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 {center_dot}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

  19. 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.

  20. 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.

  1. Intermittent Astrophysical Radiation Sources and Terrestrial Life

    Science.gov (United States)

    Melott, Adrian

    2013-04-01

    Terrestrial life is exposed to a variety of radiation sources. Astrophysical observations suggest that strong excursions in cosmic ray flux and spectral hardness are expected. Gamma-ray bursts and supernovae are expected to irradiate the atmosphere with keV to GeV photons at irregular intervals. Supernovae will produce large cosmic ray excursions, with time development varying with distance from the event. Large fluxes of keV to MeV protons from the Sun pose a strong threat to electromagnetic technology. The terrestrial record shows cosmogenic isotope excursions which are consistent with major solar proton events, and there are observations of G-stars suggesting that the rate of such events may be much higher than previously assumed. In addition there are unknown and unexplained astronomical transients which may indicate new classes of events. The Sun, supernovae, and gamma-ray bursts are all capable of producing lethal fluences, and some are expected on intervals of 10^8 years or so. The history of life on Earth is filled with mass extinctions at a variety of levels of intensity. Most are not understood. Astrophysical radiation may play a role, particularly from large increases in muon irradiation on the ground, and changes in atmospheric chemistry which deplete ozone, admitting increased solar UVB. UVB is strongly absorbed by DNA and proteins, and breaks the chemical bonds---it is a known carcinogen. High muon fluxes will also be damaging to such molecules, but experiments are needed to pin down the rate. Solar proton events which are not directly dangerous for the biota may nevertheless pose a major threat to modern electromagnetic technology through direct impact on satellites and magnetic induction of large currents in power grids, disabling transformers. We will look at the kind of events that are expected on timescales from human to geological, and their likely consequences.

  2. [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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. 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.

  5. 75 FR 19302 - Radiation Sources on Army Land

    Science.gov (United States)

    2010-04-14

    ... Department of the Army 32 CFR Part 655 RIN 0702-AA58 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 radiation sources on Army land. The Army requires Non-Army...

  6. 76 FR 6692 - Radiation Sources on Army Land

    Science.gov (United States)

    2011-02-08

    ... Department of the Army 32 CFR Part 655 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 Army land. The Army requires non-Army agencies (including...

  7. Transition undulator radiation as bright infrared sources

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.J. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

  8. 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...

  9. Sound power radiated by sources in diffuse fields

    DEFF Research Database (Denmark)

    Polack, Jean-Dominique

    2000-01-01

    Sound power radiated by sources at low frequency notoriously depends on source position. We sampled the sound field of a rectangular room at 18 microphone and 4 source positions. Average power spectra were extrapolated from the reverberant field, taking into account the frequency dependent...... reverberation times. They reveal fluctuations that depend on source position and extend far above Schroeder frequency....

  10. ORAL ISSUE OF THE JOURNAL "USPEKHI FIZICHESKIKH NAUK": Ginzburg's invention of undulators and their role in modern synchrotron radiation sources and free electron lasers

    Science.gov (United States)

    Kulipanov, Gennadii N.

    2007-04-01

    Undulators — periodic magnetic structures that were originally introduced by Vitalii Ginzburg in 1947 for electromagnetic radiation generation using relativistic electrons — are among the key elements of modern synchrotron radiation sources and free electron lasers (FELs). In this talk, the history of three generations of storage ring-based synchrotron X-ray sources using wigglers and undulators is briefly traced. Prospects for two types of next-generation space-coherent X-ray sources are discussed, which use long undulators and energy recovery accelerators or, alternatively, employ linear accelerator-based FELs. The recently developed Novosibirsk terahertz FEL facility, currently the world' s most powerful terahertz source, is described. It was the generation of electromagnetic radiation in this range that Ginzburg discussed in his 1947 work.

  11. 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.

  12. 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.

  13. Radiation sources and diagnostics with ultrashort electron bunches

    Energy Technology Data Exchange (ETDEWEB)

    Catravas, P.; Esarey, E.; Leemans, W.P.

    2001-11-02

    The basic principles and design of radiation sources (transition radiation, Cerenkov radiation, radiation from periodic structures, etc.) and radiation-based diagnostics will be discussed, with emphasis on radiation from ultra-short electron bunches. Ultra-short electron bunches have the potential to produce high peak flux radiation sources that cover wavelength regimes where sources are currently not widely available (coherent THz/IR) as well as ultrashort X-ray pulses (3-100 fs). While radiation from the electron bunch contains the full signature of the electron beam and/or medium it has travelled through, the deconvolution of a single property of interest can be difficult due to a large number of contributing properties. The experimental implementation of novel solutions to this problem will be described for beams from 30 MeV to 30 GeV, including fluctuational interferometry, source imaging, phase matched cone angles and laser-based techniques, which utilize optical transition radiation, wiggler and Cerenkov radiation, and Thomson scattering. These novel diagnostic methods have the potential to resolve fs bunch durations, slice emittance on fs scales, etc. The advantages and novel features of these techniques will be discussed.

  14. 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.

  15. 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 prior

  16. 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.

  17. Very High Power THz Radiation Sources

    OpenAIRE

    Carr, G.L.; Martin, M. C.; McKinney, W.R.; Jordan, K.; Neil, G. R.; Williams, G. P.

    2003-01-01

    We report the production of high power (20watts average, ∼ 1 Megawatt peak) broadbandTHz light based on coherent emission fromrelativistic electrons. Such sources areideal for imaging, for high power damagestudies and for studies of non-linearphenomena in this spectral range. Wedescribe the source, presenting theoreticalcalculations and their experimentalverification. For clarity we compare thissource with one based on ultrafast lasertechniques.

  18. Cryogenic Blackbody-Radiation Calibration Source

    Science.gov (United States)

    Burkett, Cecil G., Jr.; Daryabeigi, Kamran

    1993-01-01

    Operating temperatures range from ambient down to minus 100 degrees C. V-grooved front face of source body blackened and recessed in black sleeve. Semiairtight chamber that houses source purged with dry nitrogen gas to prevent formation of dew or frost at low operating temperature.

  19. Optics-less Sensors for Localization of Radiation Sources

    OpenAIRE

    Caulfield, H. J.; Yaroslavsky, L. P.; Goerzen, Ch.; Umansky, S.

    2008-01-01

    A new family of radiation sensors is introduced which do not require any optics. The sensors consist of arrays of elementary sub-sensors with natural cosine-law or similar angular sensitivity supplemented with a signal processing unit that computes optimal statistical estimations of source parameters. We show, both theoretically and by computer simulation, that such sensors are capable of accurate localization and intensity estimation of a given number of radiation sources and of imaging of a...

  20. Transition Radiation as a Secondary Standard Source in the VUV.

    Science.gov (United States)

    Böhm, W; Labs, D

    1971-09-01

    The optical radiation caused by electron bombardment of metallic surfaces was tested for its use as a secondary standard source in the VUV. Aluminum of high purity was found to be a suitable target material. The reproducibility of the radiation is of the order of 4% to 2% for 0.11 source was calibrated absolutely by comparison with a deuterium lamp of known absolute intensity.

  1. 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

  2. Feed network and electromagnetic radiation source

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. The Advanced Light Source (ALS) Radiation Safety System. Revised

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Detecting small low emission radiating sources

    CERN Document Server

    Allmaras, Moritz; Hristova, Yulia; Kanschat, Guido; Kuchment, Peter

    2010-01-01

    The article addresses the possibility of robust detection of geometrically small, low emission sources on a significantly stronger background. This problem is important for homeland security. A technique of detecting such sources using Compton type cameras is developed, which is shown on numerical examples to have high sensitivity and specificity and also allows to assign confidence probabilities of the detection. 2D case is considered in detail.

  5. 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.

  6. Diffractive triangulation of radiative point sources

    CERN Document Server

    Vespucci, Stefano; Maneuski, Dzmitry; O'Shea, Val; Winkelmann, Aimo

    2016-01-01

    We describe a general method to determine the location of a point source of waves relative to a two-dimensional active pixel detector. Based on the inherent structural sensitivity of crystalline sensor materials, characteristic detector diffraction patterns can be used to triangulate the location of a wave emitter. As a practical application of the wide-ranging principle, a digital hybrid pixel detector is used to localize a source of electrons for Kikuchi diffraction pattern measurements in the scanning electron microscope. This provides a method to calibrate Kikuchi diffraction patterns for accurate measurements of microstructural crystal orientations, strains, and phase distributions.

  7. 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.

  8. A size limit for uniformly pulsating sources of electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Dewdney, A.K.

    1979-01-01

    An extremal model for a uniformly pulsating source of electromagnetic radiation is developed, and a formula is obtained which relates the source variation to diameter, pulse width, and period. An upper limit on source diameter is derived from this formula, applied to three pulsars, and compared with standard estimates of their diameters. The use of the limit formula is shown to be no less justified, in general, than the size estimate based on the product of variation period and the speed of light.

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

    Science.gov (United States)

    2017-02-01

    Distributed Sensing for Quickest Change Detection of Point Radiation Sources Gene T. Whipps⋆† Emre Ertin† Randolph L. Moses† †The Ohio State...a radioactive source using a network of emission count sensors. Sensor nodes observe their environment and a central fusion node attempts to detect a...change in the joint probability distribution due to the appearance of a hazardous source at an unknown time and location. We consider a minimax-type

  10. Environmental radiation safety source term evaluation program

    Energy Technology Data Exchange (ETDEWEB)

    Moss, O.R.; Filipy, R.E.; Cannon, W.C.; Craig, D.K.

    1977-04-01

    Plutonium-238 is currently used in the form of a pure refractory oxide as a power source on a number of space vehicles that have already been or will be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere and impact with the earth's surface without releasing any plutonium, the possibility of such an event can never be absolutely excluded. Three separate tasks were undertaken in this study. The interactions between soils and /sup 238/PuO/sub 2/ aerosols which might be created in a space launch about environment were examined. Aging of the plutonium-soil mixture under a humid atmosphere showed a trend toward the slow coagulation of two dilute aerosols. Studies on marine animals were conducted to assess the response of /sup 238/PuO/sub 2/ pellets to conditions found 60 feet below the ocean surface. Ultrafilterability studies measured the solubility of /sup 238/PuO/sub 2/ as a function of time, temperature, suspension concentration and molality of solvent. (ACR)

  11. 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)

  12. Producing Terahertz Conherent Synchrotron Radiation Based On Hefei Light Source

    CERN Document Server

    De-Rong, Xu; Yan, Shao

    2014-01-01

    This paper theoretically proves that an electron storage ring can generate coherent radiation in THz region using a quick kicker magnet and an ac sextupole magnet. When the vertical chromaticity is modulated by the ac sextupole magnet, the vertical beam collective motion excited by the kicker produces a wavy spatial structure after a number of longitudinal oscillation periods. We calculate the radiation spectral distribution from the wavy bunch in Hefei Light Source(HLS). If we reduce electron energy to 400MeV, it can produce extremely strong coherent synchrotron radiation(CSR) at 0.115THz.

  13. Manufacture of Single 60Co Source Irradiation Facility and the Measurement of Reference Radiation Filed

    Institute of Scientific and Technical Information of China (English)

    GAO; Fei; WANG; Hong-yu; NI; Ning; ZHANG; Li; HOU; Jin-bing; SONG; Ming-zhe

    2012-01-01

    <正>Reference radiation filed produced by isotope source is necessary for calibration of radiation dose meter. 60Co single source radiation facility is an important method to produce reference radiation. Collimation design of the facility is good for characteristics of the field, but there are scattered photon influences however. Scattered radiation is mainly come from collimation, source shield, floor, walls and

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

    Energy Technology Data Exchange (ETDEWEB)

    Rittmann, P.D.

    1997-05-21

    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.

  15. 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.

  16. Network detection of radiation sources using ROSD localization

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qishi [University of Memphis; Berry, M. L.. [New Jersey Institute of Technology; Grieme, M. [New Jersey Institute of Technology; Rao, Nageswara S [ORNL; Sen, Satyabrata [ORNL; Brooks, Richard R [Clemson University

    2015-01-01

    We propose a localization-based radiation source detection (RSD) algorithm using the Ratio of Squared Distance (ROSD) method. Compared with the triangulation-based method, the advantages of this ROSD method are multi-fold: i) source location estimates based on four detectors improve their accuracy, ii) ROSD provides closed-form source location estimates and thus eliminates the imaginary-roots issue, and iii) ROSD produces a unique source location estimate as opposed to two real roots (if any) in triangulation, and obviates the need to identify real phantom roots during clustering.

  17. Smart material-based radiation sources

    Science.gov (United States)

    Kovaleski, Scott

    2014-10-01

    From sensors to power harvesters, the unique properties of smart materials have been exploited in numerous ways to enable new applications and reduce the size of many useful devices. Smart materials are defined as materials whose properties can be changed in a controlled and often reversible fashion by use of external stimuli, such as electric and magnetic fields, temperature, or humidity. Smart materials have been used to make acceleration sensors that are ubiquitous in mobile phones, to make highly accurate frequency standards, to make unprecedentedly small actuators and motors, to seal and reduce friction of rotating shafts, and to generate power by conversion of either kinetic or thermal energy to electrical energy. The number of useful devices enabled by smart materials is large and continues to grow. Smart materials can also be used to generate plasmas and accelerate particles at small scales. The materials discussed in this talk are from non-centrosymmetric crystalline classes including piezoelectric, pyroelectric, and ferroelectric materials, which produce large electric fields in response to external stimuli such as applied electric fields or thermal energy. First, the use of ferroelectric, pyroelectric and piezoelectric materials for plasma generation and particle acceleration will be reviewed. The talk will then focus on the use of piezoelectric materials at the University of Missouri to construct plasma sources and electrostatic accelerators for applications including space propulsion, x-ray imaging, and neutron production. The basic concepts of piezoelectric transformers, which are analogous to conventional magnetic transformers, will be discussed, along with results from experiments over the last decade to produce micro-thrusters for space propulsion and particle accelerators for x-ray and neutron production. Support from ONR, AFOSR, and LANL.

  18. A Close Encounter with a Saturn Kilometric Radiation Source Region

    Science.gov (United States)

    Kurth, W. S.; Gurnett, D. A.; Menietti, J. D.; Mutel, R. L.; Kivelson, M. G.; Bunce, E. J.; Cowley, S. W. H.; Talboys, D. L.; Dougherty, M. K.; Arridge, C.; Coates, A.; Grimald, S.; Lamy, L.; Zarka, P.; Cecconi, B.; Schippers, P.; André, N.; Louarn, P.; Mitchell, D.; Leisner, J.; Morooka, M.

    Earth-orbiting satellites have routinely traversed the source regions of auroral kilometric radiation. This radio emission is generated via the cyclotron maser instability very close to the electron cyclotron frequency. While Cassini's orbit has crossed auroral field lines, the radial distance at auroral latitudes is typically too high for the analogous Saturn kilometric radiation source. However, on Oct. 17, 2008, the Radio and Plasma Wave Science instrument detected the kilometric radiation at and just below the electron cyclotron frequency. At this time the spacecraft was at a distance of 5 Saturn radii, at 0.9 hours local time, and on L-shells in the range of 25 to above 30. Here the magnetic field suggests the corresponding current was directed upward, away from the planet. Low energy electron observations by the Cassini Plasma Spectrometer instrument suggest that growth of the SKR is likely due to an unstable shell-like distribution.

  19. Thermal radiation field of low-temperature sources

    Science.gov (United States)

    Łakomy, T.

    1989-05-01

    The asymmetric thermal radiation field of heat sources existing in industry and in the building of apartments has been determined in this work. A description was realised by vector radiant and mean radiant temperatures ( VRT, TMR) obtaining their statistic reciprocal relationships at summer and winter terms.

  20. Coherent Cherenkov radiation as an intense THz source

    Science.gov (United States)

    Bleko, V.; Karataev, P.; Konkov, A.; Kruchinin, K.; Naumenko, G.; Potylitsyn, A.; Vaughan, T.

    2016-07-01

    Diffraction and Cherenkov radiation of relativistic electrons from a dielectric target has been proposed as mechanism for production of intense terahertz (THz) radiation. The use of an extremely short high-energy electron beam of a 4th generation light source (X-ray free electron laser) appears to be very promising. A moderate power from the electron beam can be extracted and converted into THz radiation with nearly zero absorption losses. The initial experiment on THz observation will be performed at CLARA/VELA FEL test facility in the UK to demonstrate the principle to a wider community and to develop the radiator prototype. In this paper, we present our theoretical predictions (based on the approach of polarization currents), which provides the basis for interpreting the future experimental measurements. We will also present our hardware design and discuss a plan of the future experiment.

  1. A source-attractor approach to network detection of radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qishi [University of Memphis; Barry, M. L.. [New Jersey Institute of Technology; Grieme, M. [New Jersey Institute of Technology; Sen, Satyabrata [ORNL; Rao, Nageswara S [ORNL; Brooks, Richard R [Clemson University

    2016-01-01

    Radiation source detection using a network of detectors is an active field of research for homeland security and defense applications. We propose Source-attractor Radiation Detection (SRD) method to aggregate measurements from a network of detectors for radiation source detection. SRD method models a potential radiation source as a magnet -like attractor that pulls in pre-computed virtual points from the detector locations. A detection decision is made if a sufficient level of attraction, quantified by the increase in the clustering of the shifted virtual points, is observed. Compared with traditional methods, SRD has the following advantages: i) it does not require an accurate estimate of the source location from limited and noise-corrupted sensor readings, unlike the localizationbased methods, and ii) its virtual point shifting and clustering calculation involve simple arithmetic operations based on the number of detectors, avoiding the high computational complexity of grid-based likelihood estimation methods. We evaluate its detection performance using canonical datasets from Domestic Nuclear Detection Office s (DNDO) Intelligence Radiation Sensors Systems (IRSS) tests. SRD achieves both lower false alarm rate and false negative rate compared to three existing algorithms for network source detection.

  2. Accelerator Based Tools of Stockpile Stewardship

    Science.gov (United States)

    Seestrom, Susan

    2017-01-01

    The Manhattan Project had to solve difficult challenges in physics and materials science. During the cold war a large nuclear stockpile was developed. In both cases, the approach was largely empirical. Today that stockpile must be certified without nuclear testing, a task that becomes more difficult as the stockpile ages. I will discuss the role of modern accelerator based experiments, such as x-ray radiography, proton radiography, neutron and nuclear physics experiments, in stockpile stewardship. These new tools provide data of exceptional sensitivity and are answering questions about the stockpile, improving our scientific understanding, and providing validation for the computer simulations that are relied upon to certify todays' stockpile.

  3. 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

  4. Radiation efficiency of earthquake sources at different hierarchical levels

    Energy Technology Data Exchange (ETDEWEB)

    Kocharyan, G. G., E-mail: gevorgkidg@mail.ru [Institute of Dynamics of Geospheres RAS, Moscow, 119334 (Russian Federation); Moscow Institute of Physics and Technology (State University), Dolgoprudny, 117303 (Russian Federation)

    2015-10-27

    Such factors as earthquake size and its mechanism define common trends in alteration of radiation efficiency. The macroscopic parameter that controls the efficiency of a seismic source is stiffness of fault or fracture. The regularities of this parameter alteration with scale define several hierarchical levels, within which earthquake characteristics obey different laws. Small variations of physical and mechanical properties of the fault principal slip zone can lead to dramatic differences both in the amplitude of released stress and in the amount of radiated energy.

  5. Handling radiation generated during an ion source commissioning

    Science.gov (United States)

    Ren, H. T.; Zhao, J.; Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Xu, Y.; Chen, J.; Zhang, T.; Zhang, A. L.; Guo, Z. Y.; Chen, J. E.

    2014-02-01

    Radiation is an important issue, which should be carefully treated during the design and commissioning of an ion source. Measurements show that X-rays are generated around the ceramics column of an extraction system when the source is powered up to 30 kV. The X-ray dose increases greatly when a beam is extracted. Inserting the ceramic column into a metal vacuum box is a good way to block X-ray emission for those cases. Moreover, this makes the online test of an intense H+ ion beam with energy up to 100 keV possible. However, for deuteron ion source commissioning, neutron and gamma-ray radiation become a serious topic. In this paper, we will describe the design of the extraction system and the radiation doses of neutrons and gamma-rays measured at different D+ beam energy during our 2.45 GHz deuteron electron cyclotron resonance ion source commissioning for PKUNIFTY (PeKing University Neutron Imaging FaciliTY) project at Peking University.

  6. Helium Reionization Simulations. I. Modeling Quasars as Radiation Sources

    CERN Document Server

    La Plante, Paul

    2015-01-01

    We introduce a new project to understand helium reionization using fully coupled $N$-body, hydrodynamics, and radiative transfer simulations. This project aims to capture correctly the thermal history of the intergalactic medium (IGM) as a result of reionization and make predictions about the Lyman-$\\alpha$ forest and baryon temperature-density relation. The dominant sources of radiation for this transition are quasars, so modeling the source population accurately is very important for making reliable predictions. In this first paper, we present a new method for populating dark matter halos with quasars. Our set of quasar models include two different light curves, a lightbulb (simple on/off) and symmetric exponential model, and luminosity-dependent quasar lifetimes. Our method self-consistently reproduces an input quasar luminosity function (QLF) given a halo catalog from an $N$-body simulation, and propagates quasars through the merger history of halo hosts. After calibrating quasar clustering using measurem...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Yasser A.; Spencer, James E.; /SLAC

    2005-06-07

    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 CO{sub 2} lasers. While the physical implementations of these two approaches are quite different, both are proving difficult to develop so that lower frequency, superconducting RF is currently preferred. Similarly, the validity of modeling 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 study radiation from undulatory-shaped transmission lines using finite-difference, time-domain (FDTD) simulations. Also, we present Monte-Carlo techniques for pulse generation. Examples of THz sources demonstrating coherence are shown with the goal of optimizing on-chip THz radiators for applications that may lead to accelerators.

  8. Radiation Parameters of High Dose Rate Iridium -192 Sources

    Science.gov (United States)

    Podgorsak, Matthew B.

    A lack of physical data for high dose rate (HDR) Ir-192 sources has necessitated the use of basic radiation parameters measured with low dose rate (LDR) Ir-192 seeds and ribbons in HDR dosimetry calculations. A rigorous examination of the radiation parameters of several HDR Ir-192 sources has shown that this extension of physical data from LDR to HDR Ir-192 may be inaccurate. Uncertainty in any of the basic radiation parameters used in dosimetry calculations compromises the accuracy of the calculated dose distribution and the subsequent dose delivery. Dose errors of up to 0.3%, 6%, and 2% can result from the use of currently accepted values for the half-life, exposure rate constant, and dose buildup effect, respectively. Since an accuracy of 5% in the delivered dose is essential to prevent severe complications or tumor regrowth, the use of basic physical constants with uncertainties approaching 6% is unacceptable. A systematic evaluation of the pertinent radiation parameters contributes to a reduction in the overall uncertainty in HDR Ir-192 dose delivery. Moreover, the results of the studies described in this thesis contribute significantly to the establishment of standardized numerical values to be used in HDR Ir-192 dosimetry calculations.

  9. RF gun for an intense THz radiation source

    Institute of Scientific and Technical Information of China (English)

    GU Qiang; ZHAO Zhen-Tang; TONG De-Chun; CHEN Li-Fang; XU Xiu-Min

    2008-01-01

    A new facility is under construction at the Shanghai Institute of Applied Physics,to generate femto-second electron bunches and intense coherent THz radiation pulses.A thermionic RF-gun is used to be the electron source of the linac,which is 1.6 cell,π/2,side coupled in design.In the following of this paper,the design,manufacture and beam operation of this gun are presented.

  10. Cosmic Radiation Fields: Sources in the early Universe

    Science.gov (United States)

    Raue, Martin; Kneiske, Tanja; Horns, Dieter; Elsaesser, Dominik; Hauschildt, Peter

    The workshop "Cosmic Radiation Fields - Sources in the Early Universe" (CRF 2010) focuses on the connection between the extragalactic infrared background and sources in the early universe, in particular stars powered by dark matter burning (Dark Stars; DS). The workshop covers the following topics: the cosmic infrared background, formation of early stars, dark stars, effect of dark matter in the early universe, dark matter halos, primordial star formation rate, and reionization. Further information can be found on the conference webpage: http://www.desy.de/crf2010/. Organizing committee: Tanja Kneiske, Martin Raue, Dominik Elsaesser, Alexander Gewering-Peine, Peter Hausschildt, Dieter Horns, and Andreas Maurer.

  11. A high-power synthesized ultrawideband radiation source

    Science.gov (United States)

    Efremov, A. M.; Koshelev, V. I.; Plisko, V. V.; Sevostyanov, E. A.

    2017-09-01

    A high-power ultrawideband radiation source has been developed which is capable of synthesizing electromagnetic pulses with different frequency bands in free space. To this end, a new circuit design comprising a four-channel former of bipolar pulses of durations 2 and 3 ns has been elaborated and conditions for the stable operation of gas gaps of independent channels without external control pulses have been determined. Each element of the 2 × 2 array of combined antennas is driven from an individual channel of the pulse former. Antennas excited by pulses of the same duration are arranged diagonally. Two radiation synthesis modes have been examined: one aimed to attain ultimate field strength and the other aimed to attain an ultimate width of the radiation spectrum. The modes were changed by changing the time delay between the 2-ns and 3-ns pulses. For the first mode, radiation pulses with a frequency band of 0.2-0.8 GHz and an effective potential of 500 kV have been obtained. The synthesized radiation pulses produced in the second mode had an extended frequency band (0.1-1 GHz) and an effective potential of 220 kV. The pulse repetition frequency was 100 Hz.

  12. Helium Reionization Simulations. I. Modeling Quasars as Radiation Sources

    Science.gov (United States)

    La Plante, Paul; Trac, Hy

    2016-09-01

    We introduce a new project to understand helium reionization using fully coupled N-body, hydrodynamics, and radiative transfer simulations. This project aims to capture correctly the thermal history of the intergalactic medium as a result of reionization and make predictions about the Lyα forest and baryon temperature-density relation. The dominant sources of radiation for this transition are quasars, so modeling the source population accurately is very important for making reliable predictions. In this first paper, we present a new method for populating dark matter halos with quasars. Our set of quasar models includes two different light curves, a lightbulb (simple on/off) and symmetric exponential model, and luminosity-dependent quasar lifetimes. Our method self-consistently reproduces an input quasar luminosity function given a halo catalog from an N-body simulation, and propagates quasars through the merger history of halo hosts. After calibrating quasar clustering using measurements from the Baryon Oscillation Spectroscopic Survey, we find that the characteristic mass of quasar hosts is {M}h˜ 2.5× {10}12 {h}-1 {M}⊙ for the lightbulb model, and {M}h˜ 2.3× {10}12 {h}-1 {M}⊙ for the exponential model. In the latter model, the peak quasar luminosity for a given halo mass is larger than that in the former, typically by a factor of 1.5-2. The effective lifetime for quasars in the lightbulb model is 59 Myr, and in the exponential case, the effective time constant is about 15 Myr. We include semi-analytic calculations of helium reionization, and discuss how to include these quasars as sources of ionizing radiation for full hydrodynamics with radiative transfer simulations in order to study helium reionization.

  13. Characterization of the radiation background at the Spallation Neutron Source

    Science.gov (United States)

    DiJulio, Douglas D.; Cherkashyna, Nataliia; Scherzinger, Julius; Khaplanov, Anton; Pfeiffer, Dorothea; Cooper-Jensen, Carsten P.; Fissum, Kevin G.; Kanaki, Kalliopi; Kirstein, Oliver; Ehlers, Georg; Gallmeier, Franz X.; Hornbach, Donald E.; Iverson, Erik B.; Newby, Robert J.; Hall-Wilton, Richard J.; Bentley, Phillip M.

    2016-09-01

    We present a survey of the radiation background at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, TN, USA during routine daily operation. A broad range of detectors was used to characterize primarily the neutron and photon fields throughout the facility. These include a WENDI-2 extended range dosimeter, a thermoscientific NRD, an Arktis 4He detector, and a standard NaI photon detector. The information gathered from the detectors was used to map out the neutron dose rates throughout the facility and also the neutron dose rate and flux profiles of several different beamlines. The survey provides detailed information useful for developing future shielding concepts at spallation neutron sources, such as the European Spallation Source (ESS), currently under construction in Lund, Sweden.

  14. An oil-free compact X-pinch plasma radiation source: Design and radiation performance

    Science.gov (United States)

    Shapovalov, Roman V.; Spielman, Rick B.; Imel, George R.

    2017-06-01

    This paper describes a new, high-current, X-pinch radiation source recently developed and tested at Idaho State University. Our design is based on two linear transformer driver (LTD) bricks arranged in side-by-side geometry and directly coupled with an X-pinch load. The salient features of our 2-LTD-bricks are its simplicity, compactness, and portability: there is no oil, no water, and no SF6. It can be easily relocated to any place where a compact X-pinch radiation source is wanted. The driver can store up to 2.8 kJ of initial energy and can deliver more than 200-kA peak-current with less than 200-ns, 10%-90%, rise time into a short-circuit load. When the driver is coupled with an X-pinch load, it generates a very fast and bright radiation pulse. Source size measurements indicate that this radiation originates from a very small dense plasma, known as a "hot spot."

  15. Health risk assessment of jobs involving ionizing radiation sources

    Directory of Open Access Journals (Sweden)

    Spasojević-Tišma Vera D.

    2011-01-01

    Full Text Available The study included 75 subjects exposed to low doses of external ionizing radiation and 25 subjects from the control group, all male. The first group (A consisted of 25 subjects employed in the production of technetium, with an average job experience of 15 years. The second group (B consisted of 25 subjects exposed to ionizing radiation from enclosed sources, working in jobs involving the control of X-ray devices and americium smoke detectors, their average work experience being 18.5 years. The third group (C consisted of 25 subjects involved in the decontamination of the terrain at Borovac from radioactive rounds with depleted uranium left over after the NATO bombing of Serbia in 1999, their average job experience being 18.5 years. The control group (K consisted of 25 subjects who have not been in contact with sources of ionizing radiation and who hold administrative positions. Frequencies of chromosome aberrations were determined in lymphocytes of peripheral blood and compared to the control group. The average annual absorbed dose determined by thermoluminescent dosimeters for all three groups did not exceed 2 mSv. In the present study, the largest number of observed changes are acentric fragments and chromosome breaks. The highest occupational risk appears to involve subjects working in manufacturing of the radio-isotope technetium.

  16. Inner radiation belt source of helium and heavy hydrogen isotopes

    Science.gov (United States)

    Leonov, A. A.; Galper, A. M.; Koldashov, S. V.; Mikhailov, V. V.; Casolino, M.; Picozza, P.; Sparvoli, R.

    Nuclear interactions between inner zone protons and atoms in the upper atmosphere provide the main source of energetic H and He isotopes nuclei in the radiation belt. This paper reports on the specified calculations of these isotope intensities using various inner zone proton intensity models (AP-8 and SAMPEX/PET PSB97), the atmosphere drift-averaged composition and density model MSIS-90, and cross-sections of the interaction processes from the GNASH nuclear model code. To calculate drift-averaged densities and energy losses of secondaries, the particles were tracked in the geomagnetic field (modelled through IGRF-95) by integrating numerically the equation of the motion. The calculations take into account the kinematics of nuclear interactions along the whole trajectory of trapped proton. The comparison with new data obtained from the experiments on board RESURS-04 and MITA satellites and with data from SAMPEX and CRRES satellites taken during different phases of solar activity shows that the upper atmosphere is a sufficient source for inner zone helium and heavy hydrogen isotopes. The calculation results are energy spectra and angular distributions of light nuclear isotopes in the inner radiation belt that may be used to develop helium inner radiation belt model and to evaluate their contribution to SEU (single event upset) rates.

  17. Radiation damage of the ILC positron source target

    Energy Technology Data Exchange (ETDEWEB)

    Ushakov, A.; Riemann, S.

    2007-11-15

    The radiation damage of the positron source target for the International Linear Collider (ILC) has been studied. The displacement damage in target material due to multi-MeV photons has been calculated by combining FLUKA simulations for secondary particle production, SPECTER data for neutron displacement cross-sections and the Lindhard model for estimations of displacement damage by ions. The radiation damage of a stationary Ti6Al4V target in units of displacements per atom (dpa) has been estimated for photons from an undulator with strength 0.92 and period 1.15 cm. The calculated damage is 7 dpa. Approximately 12.5% of displacement damage result from neutrons. (orig.)

  18. Optimization of a Water Window Capillary Discharge Radiation Source

    Directory of Open Access Journals (Sweden)

    M. Stefanovič

    2011-01-01

    Full Text Available Computer modeling of a fast electrical discharge in a nitrogen-filled alumina capillary was performed in order to discover discharge system parameters that lead to high radiation intensity in the so-called water window range of wavelengths (2–4 nm. The modeling was performed by means of the two-dimensional RMHD code Z*. The time and spatial distribution of plasma quantities were used for calculating the ion level populations and for estimating the absorption of the 2.88 nm radiation line in the capillary plasma, using the FLYCHK code. Optimum discharge parameters for the capillary discharge water window source are suggested. The heating of the electrodes and the role of capillary channel shielding were analyzed according to the Z* code.

  19. Radiation damage of the ILC positron source target

    Energy Technology Data Exchange (ETDEWEB)

    Ushakov, A.; Riemann, S.

    2007-11-15

    The radiation damage of the positron source target for the International Linear Collider (ILC) has been studied. The displacement damage in target material due to multi-MeV photons has been calculated by combining FLUKA simulations for secondary particle production, SPECTER data for neutron displacement cross-sections and the Lindhard model for estimations of displacement damage by ions. The radiation damage of a stationary Ti6Al4V target in units of displacements per atom (dpa) has been estimated for photons from an undulator with strength 0.92 and period 1.15 cm. The calculated damage is 7 dpa. Approximately 12.5% of displacement damage result from neutrons. (orig.)

  20. Commissioning of a compact synchrotron radiation source at Hiroshima University

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, K.; Andreyashkin, M.; Goto, K. [Hiroshima Univ. (Japan)] [and others

    1998-11-01

    A 700 MeV synchrotron radiation source is under commissioning at Hiroshima University. The ring is of a racetrack type with two undulators, linear and helical ones, at the long straight sections. The bending field, produced by normal conducting magnet, is as strong as 2.7 Tesla, which generates as high radiation power as compatible with the one from usual 1.6 GeV ring. 14 beam-ports from the bending sections together with two from the undulators are prepared. The injector is a 150 MeV racetrack microtron, which is used also for other purposes than the beam injection into the storage ring. As of March 1998, the stored current is typically 100 mA at start and the beam lifetime is three hours. We expect the beam lifetime will be extended to be eight hours after degassing operation for another few months. (author)

  1. 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.

  2. AREAL test facility for advanced accelerator and radiation source concepts

    Energy Technology Data Exchange (ETDEWEB)

    Tsakanov, V.M., E-mail: tsakanov@asls.candle.am [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Amatuni, G.A.; Amirkhanyan, Z.G.; Aslyan, L.V.; Avagyan, V.Sh.; Danielyan, V.A.; Davtyan, H.D.; Dekhtiarov, V.S.; Gevorgyan, K.L.; Ghazaryan, N.G.; Grigoryan, B.A.; Grigoryan, A.H.; Hakobyan, L.S. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Haroutiunian, S.G. [Yerevan State University, 0025 Yerevan (Armenia); Ivanyan, M.I.; Khachatryan, V.G.; Laziev, E.M. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); Manukyan, P.S. [State Engineering University of Armenia, 0009 Yerevan (Armenia); Margaryan, I.N.; Markosyan, T.M. [CANDLE Synchrotron Research Institute, 0040 Yerevan (Armenia); and others

    2016-09-01

    Advanced Research Electron Accelerator Laboratory (AREAL) is a 50 MeV electron linear accelerator project with a laser driven RF gun being constructed at the CANDLE Synchrotron Research Institute. In addition to applications in life and materials sciences, the project aims as a test facility for advanced accelerator and radiation source concepts. In this paper, the AREAL RF photoinjector performance, the facility design considerations and its highlights in the fields of free electron laser, the study of new high frequency accelerating structures, the beam microbunching and wakefield acceleration concepts are presented.

  3. Effects of Source Correlations on the Spectrum of Radiated Fields

    Science.gov (United States)

    1990-09-01

    directivltv Chapter 2 68 12 K. Kim and E. Wolf, "Non-radiating monochromatic sources and their fields", Opt. Commun. 59, 1-6 (1986). 13 The Jacobian of...Amer. 68 , 1597-1605 (1978). 15 R. Bracewell, The Fourier Transform and Its Applications (McGraw-Hill, New York, 1965), Chap. 6. 16 The method of...Ghatak and C.L. Metha, "Propagation of a partially coherent beam through selfoc fibers", Opt. Commun. 12, 333-337(1974). D. Marcuse , Light Transmission

  4. 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.

  5. Designing accelerator-based epithermal neutron beams for boron neutron capture therapy.

    Science.gov (United States)

    Bleuel, D L; Donahue, R J; Ludewigt, B A; Vujic, J

    1998-09-01

    The 7Li(p,n)7Be reaction has been investigated as an accelerator-driven neutron source for proton energies between 2.1 and 2.6 MeV. Epithermal neutron beams shaped by three moderator materials, Al/AlF3, 7LiF, and D2O, have been analyzed and their usefulness for boron neutron capture therapy (BNCT) treatments evaluated. Radiation transport through the moderator assembly has been simulated with the Monte Carlo N-particle code (MCNP). Fluence and dose distributions in a head phantom were calculated using BNCT treatment planning software. Depth-dose distributions and treatment times were studied as a function of proton beam energy and moderator thickness. It was found that an accelerator-based neutron source with Al/AlF3 or 7LiF as moderator material can produce depth-dose distributions superior to those calculated for a previously published neutron beam design for the Brookhaven Medical Research Reactor, achieving up to approximately 50% higher doses near the midline of the brain. For a single beam treatment, a proton beam current of 20 mA, and a 7LiF moderator, the treatment time was estimated to be about 40 min. The tumor dose deposited at a depth of 8 cm was calculated to be about 21 Gy-Eq.

  6. The source of cosmic radiations; A la source des rayons cosmiques

    Energy Technology Data Exchange (ETDEWEB)

    Letessier-Selvon, A. [Laboratoire de Physique Nucleaire et Hautes Energies, 75 - Paris (France)

    2008-11-15

    The existence of the GZD (Greisen-Zatsepin-Kuzmin) limit comes from the fact that the cosmological diffuse background interacts with cosmological radiations and can reduce dramatically their energy. As a consequence cosmic radiations traveling over large intergalactic distances can not have an energy over 60*10{sup 18} eV (the GZK limit). Another consequence is that a cosmic radiation with an energy greater that the GZK limit comes necessarily from a region no more than 500 million light-years away. The Auger observatory that at term will cover a surface of 3000 km{sup 2} has been designed to study high energy cosmic radiations through the detection of the huge particle showers they trigger when interacting with particles from the upper part of the atmosphere. The first results of the Auger observatory shows three important things. First, the Auger detector's ability to detect is 30 times greater than that of previous experiments. Secondly, 27 events with an energy greater than the GZK limit have been detected and for 20 of them a very active galaxy is located in their incident direction within a distance of 300*10{sup 6} km, these galaxies are then highly suspected to be the source of very high energy cosmic radiations. Thirdly, the graph of the measured cosmic radiation flux shows a brutal drop around 60*10{sup 18} eV which is the GZK limit. (A.C.)

  7. 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.

  8. First accelerator-based physics of 2014

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    Experiments in the East Area received their first beams from the PS this week. Theirs is CERN's first accelerator-based physics since LS1 began last year.   For the East Area, the PS performs a so-called slow extraction, where beam is extracted during many revolution periods (the time it take for particles to go around the PS, ~2.1 μs). The yellow line shows the circulating beam current in the PS, decreasing slowly during the slow extraction, which lasts 350 ms. The green line is the measured proton intensity in the transfer line toward the East Area target. Although LHC physics is still far away, we can now confirm that the injectors are producing physics! In the East Area - the experimental area behind the PS - the T9 and T10 beam lines are providing beams for physics. These beam lines serve experiments such as AIDA - which looks at new detector solutions for future accelerators - and the ALICE Inner Tracking System - which tests components for the ALICE experiment. &qu...

  9. Radiation sources for engineering and medicine. 2. rev. and enl. ed.; Strahlungsquellen fuer Technik und Medizin

    Energy Technology Data Exchange (ETDEWEB)

    Krieger, Hanno

    2013-07-01

    The book on radiation sources for engineering and medicine includes the following issues: Part I: Particle accelerators: review on radiation sources; fundamentals on particle accelerators and radiation optics; electron an ion sources, the X-ray tube; DC accelerators; high-frequency generators; hollow wave guides and cavity resonators; linear accelerators; medical electron linear accelerators; ring accelerators; synchrotron radiation and storage rings. Part II: Nuclear reactors and neutron sources: nuclear reactors; neutron sources and their applications. Part III: Radionuclides and their application: radionuclide production; radionuclides in medicine; cobalt radiation facilities for medicine; afterloading facilities for medicine; technical applications for radionuclides. Part IV: Attachments: tables; literature.

  10. Analysis of Saturn kilometric radiation near a source center

    Science.gov (United States)

    Menietti, J. D.; Mutel, R. L.; Schippers, P.; Ye, S.-Y.; Gurnett, D. A.; Lamy, L.

    2011-12-01

    The Cassini spacecraft flew very near a source region of Saturn kilometric radiation (SKR) on day 73 of 2008, the second known encounter with a source region at high latitude. The radio and plasma wave instrument, Radio and Plasma Wave Science, observed intense kilometric emission in the extraordinary X mode, ordinary O mode, and Z mode. The electron low-energy spectrometer obtained a phase space distribution of sufficient energy and pitch angle resolution to allow growth rate calculations. There is evidence of a shell-like electron plasma distribution that is unstable to the growth of SKR via the cyclotron maser instability. The growth rates calculated are adequate to explain the observed X and Z mode emission, but nonlinear effects are required to explain the large O mode gain (as is true for terrestrial observations). Narrowband emission, also present at the time, could also explain both the Z mode and the O mode. We present the results for comparison with a previously reported source region encounter and with similar observations at Earth auroral kilometric source regions.

  11. SU-C-16A-06: Optimum Radiation Source for Radiation Therapy of Skin Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Safigholi, Habib [Science and Research Branch, Islamic Azad University, Fars, Persepolis (Iran, Islamic Republic of); Meigooni, A S. [Comprehensive cancer center of Nevada, Las Vegas, NV (United States); University of Nevada Las Vegas (UNLV), Las Vegas, NV (United States)

    2014-06-15

    Purpose: Recently, different applicators are designed for treatment of the skin cancer such as scalp and legs, using Ir-192 HDR Brachytherapy Sources (IR-HDRS), Miniature Electronic Brachytherapy Sources (MEBXS), and External Electron Beam Radiation Therapy (EEBRT). Although, all of these methodologies may deliver the desired radiation dose to the skin, the dose to the underlying bone may become the limiting factor for selection of the optimum treatment technique. In this project the radiation dose delivered to the underlying bone has been evaluated as a function of the radiation source and thickness of the underlying bone. Methods: MC simulations were performed using MCNP5 code. In these simulations, the mono-energetic and non-divergent photon beams of 30 keV, 50 keV, and 70 keV for MEBXS, 380 keV photons for IR-HDRS, and 6 MeV mono-energetic electron beam for EEBRT were modeled. A 0.5 cm thick soft tissue (0.3 cm skin and 0.2 cm adipose) with underlying 0.5 cm cortical bone followed by 14 cm soft tissue are utilized for simulations. Results: Dose values to bone tissue as a function of beam energy and beam type, for a delivery of 5000 cGy dose to skin, were compared. These results indicate that for delivery of 5000 cGy dose to the skin surface with 30 keV, 50 keV, 70 keV of MEBXS, IR-HDRS, and EEBRT techniques, bone will receive 31750 cGy, 27450 cGy, 18550 cGy, 4875 cGy, and 10450 cGy, respectively. Conclusion: The results of these investigations indicate that, for delivery of the same skin dose, average doses received by the underlying bone are 5.2 and 2.2 times larger with a 50 keV MEBXS and EEBRT techniques than IR-HDRS, respectively.

  12. Accelerator-based neutrino oscillation searches

    Science.gov (United States)

    Whitehouse, D. A.; Rameika, R.; Stanton, N.

    This paper attempts to summarize the neutrino oscillation section of the Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Beam Facilities. There were very lively discussions about the merits of the different oscillation channels, experiments, and facilities, but we believe a substantial consensus emerged. First, the next decade is one of great potential for discovery in neutrino physics, but it is also one of great peril. The possibility that neutrino oscillations explain the solar neutrino and atmospheric neutrino experiments, and the indirect evidence that Hot Dark Matter (HDM) in the form of light neutrinos might make up 30% of the mass of the universe, point to areas where accelerator-based experiments could play a crucial role in piecing together the puzzle. At the same time, the field faces a very uncertain future. The LSND experiment at LAMPF is the only funded neutrino oscillation experiment in the United States and it is threatened by the abrupt shutdown of LAMPF proposed for fiscal 1994. The future of neutrino physics at the Brookhaven National Laboratory AGS depends on the continuation of High Energy Physics (HEP) funding after the RHIC startup. Most proposed neutrino oscillation searches at Fermilab depend on the completion of the Main Injector project and on the construction of a new neutrino beamline, which is uncertain at this point. The proposed KAON facility at TRIUMF would provide a neutrino beam similar to that at the AGS but with a much increased intensity. The future of KAON is also uncertain. Despite the difficult obstacles present, there is a real possibility that we are on the verge of understanding the masses and mixings of the neutrinos. The physics importance of such a discovery cannot be overstated. The current experimental status and future possibilities are discussed.

  13. 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.

  14. High-power liquid-lithium target prototype for accelerator-based boron neutron capture therapy.

    Science.gov (United States)

    Halfon, S; Paul, M; Arenshtam, A; Berkovits, D; Bisyakoev, M; Eliyahu, I; Feinberg, G; Hazenshprung, N; Kijel, D; Nagler, A; Silverman, I

    2011-12-01

    A prototype of a compact Liquid-Lithium Target (LiLiT), which will possibly constitute an accelerator-based intense neutron source for Boron Neutron Capture Therapy (BNCT) in hospitals, was built. The LiLiT setup is presently being commissioned at Soreq Nuclear Research Center (SNRC). The liquid-lithium target will produce neutrons through the (7)Li(p,n)(7)Be reaction and it will overcome the major problem of removing the thermal power generated using a high-intensity proton beam (>10 kW), necessary for sufficient neutron flux. In off-line circulation tests, the liquid-lithium loop generated a stable lithium jet at high velocity, on a concave supporting wall; the concept will first be tested using a high-power electron beam impinging on the lithium jet. High intensity proton beam irradiation (1.91-2.5 MeV, 2-4 mA) will take place at Soreq Applied Research Accelerator Facility (SARAF) superconducting linear accelerator currently in construction at SNRC. Radiological risks due to the (7)Be produced in the reaction were studied and will be handled through a proper design, including a cold trap and appropriate shielding. A moderator/reflector assembly is planned according to a Monte Carlo simulation, to create a neutron spectrum and intensity maximally effective to the treatment and to reduce prompt gamma radiation dose risks.

  15. Radiative excitation of molecules near powerful compact radio sources

    Science.gov (United States)

    Maloney, Philip R.; Begelman, Mitchell C.; Rees, Martin J.

    1994-01-01

    In a recent paper, Barvainis & Antonucci searched for and failed to detect CO J = 1 goes to 0 absorption from the obscuring torus in the nearby powerful radio galaxy Cygnus A. We show that a plausible explanation for the lack of absorption (assuming that the ionization parameter within the torus is low enough for the gas to be molecular) is that radiative excitation of the CO molecules by the nonthermal radio continuum increases the excitation temperature of the lower rotational levels substantially, reducing the optical depths. The excitation temperature may approach the brightness temperature of the radio source at high enough flux-to-density ratios. Heating of the gas by the nonthermal excitation may also be important. We discuss the region of parameter space in which this excitation mechanism will be important and the implications for observations of obscuring tori.

  16. An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Anania, M. P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); INFN, Laboratori Nazionali di Frascati, I-00044 Frascati (Italy); Brunetti, E.; Wiggins, S. M.; Grant, D. W.; Welsh, G. H.; Issac, R. C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; Jaroszynski, D. A., E-mail: d.a.jaroszynski@strath.ac.uk [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Geer, S. B. van der; Loos, M. J. de [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands); Poole, M. W.; Shepherd, B. J. A.; Clarke, J. A. [ASTeC, STFC, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Gillespie, W. A. [SUPA, School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); MacLeod, A. M. [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee DD1 1HG (United Kingdom)

    2014-06-30

    Narrow band undulator radiation tuneable over the wavelength range of 150–260 nm has been produced by short electron bunches from a 2 mm long laser plasma wakefield accelerator based on a 20 TW femtosecond laser system. The number of photons measured is up to 9 × 10{sup 6} per shot for a 100 period undulator, with a mean peak brilliance of 1 × 10{sup 18} photons/s/mrad{sup 2}/mm{sup 2}/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130 MeV with the radiation pulse duration in the range of 50–100 fs.

  17. Electron Beam Diagnostics at the Radiation Source ELBE

    Science.gov (United States)

    Evtushenko, P.; Lehnert, U.; Michel, P.; Schneider, C.; Schurig, R.; Teichert, J.

    2002-12-01

    In the research center Rossendorf, the radiation source ELBE, based on a super conducting LINAC, is under construction. In the year 2001 the first accelerating module was commissioned. The electron beam parameters like emittance, bunch length, energy spread were measured. Here we present results of the measurements as well as the methods used to make the measurements. In the ELBE injector, where electron beam energy is 250 keV, the emittance was measured with the aid of a multislit device. Emittance of the accelerated beam was measured by means of quadrupole scan method and is 8 mm×mrad at 77 pC bunch charge. Electron bunch length was measured using the coherent transition radiation technique. At the maximum design bunch charge of 77 pC the RMS bunch length was measured to be 2 ps. A set of online diagnostic systems is also under development. One these include a system of stripline beam position monitors is also described here. A BPM resolution of about 10 μm was achieved using logarithmic amplifier as the core element of the BPM electronics. A system of beam loss monitors based on the RF Heliax cable working as an ionization chamber is intended to be another online diagnostic system.

  18. Uranium target for electron accelerator based neutron source for BNCT

    Science.gov (United States)

    Tonchev, A. P.; Harmon, F.; Collens, T. J.; Kennedy, K.; Sabourov, A.; Harker, Y. D.; Nigg, D. W.; Jones, J. L.

    2001-07-01

    Calculations of the epithermal-neutron yield of photoneutrons from a uranium-beryllium converter using a 27 MeV electron linear accelerator have been investigated. In this concept, relativistic electron beams from a 30 MeV LINAC impinge upon a small uranium sphere surrounded by a cylindrical tank of circulating heavy water (D2O) nested in a beryllium cube. The photo-fission neutron spectrum from the uranium sphere is thermalized in deuterium and beryllium, filtered and moderated in special material (AlF3/Al/LiF), and directed to the patient. The results of these calculations demonstrate that photoneutron devices could offer a promising alternative to nuclear reactors for the production of epithermal neutrons for Neutron Capture Therapy. The predicted parameter for the epithermal flux is more than 108n.cm-2.mA-1.

  19. Naturally occurring radiation sources: existing or planned exposure situation?

    Energy Technology Data Exchange (ETDEWEB)

    Hedemann-Jensen, Per [Danish Decommissioning, DK-4000 Roskilde (Denmark)

    2010-12-01

    After more than fifteen years of application, ICRP Publication 60 has been revised. The revision was based upon the concept of 'controllable dose' as the dose or sum of doses to an individual from a particular source that can reasonably be controlled by whatever means. The new recommendations have been published as ICRP Publication 103. The European Basic Safety Standards as well as the International Basic Safety Standards are currently under revision as a result of the new recommendations from ICRP. According to the ICRP, there have been indications that some changes to the structure and terminology of the system of protection were desirable in order to improve clarity and utility. In particular the distinction between practices and interventions may not have been clearly understood and the ICRP now recognises three types of exposure situations, which replace the previous categorisation into practices and interventions. These exposure situations are intended to cover the entire range of exposure situations: (1) planned exposure, (2) existing exposure and (3) emergency exposure. There are situations of exposure to naturally occurring radiation sources in different occupations, e.g. exposure to radon and radon progeny in workplaces other than where the exposure is required by or is directly related to the work and aircrew exposed to cosmic radiation. In the European (Euratom) and the International Basic Safety Standards, these exposure situations are treated conceptually different-either as a planned exposure situation or as an existing exposure situation. This note reviews the change of exposure situations from Publication 60 to Publication 103 and the implications for the revision of both the International and the European Basic Safety Standards. The paper draws some conclusions on the classification of the exposure situations in the two basic safety standards based on a logical interpretation of the ICRP recommendations. It is recommended that the

  20. Acoustic radiation field of the truncated parametric source generated by a piston radiator model and experiment

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiaoliang; ZHU Zhemin; DU Gonghuan; TANG Haiqing; LI Shui; MIAO Rongxing

    2001-01-01

    A theoretical model is presented to describe the parametric acoustic field generated by a piston radiator. In the model, the high-frequency primary wave interaction region that is truncated by a low-pass acoustic filter can be viewed as a cylindrical source within the Rayleigh distance of the piston. When the radius of the piston is much smaller than the length of the parametric region, this model is reduced to the Berketey's End-Fire Line Array model. Comparison between numerical calculations and experimental measurement show that the generated parametric sound field (especially near the axis) agrees well with the experiment results.

  1. GCR as a source for Inner radiation belt of Saturn.

    Science.gov (United States)

    Kotova, A.; Roussos, E.; Krupp, N.; Dandouras, I. S.

    2014-12-01

    During the insertion orbit of Cassini in 2004 the Ion and Neutron Camera measured significant fluxes of the energetic neutral atoms (ENA) coming from the area between the D-ring and the Saturn's atmosphere, what brought up the idea of the possible existence of the innermost radiation belt in this narrow gap (1). There are two main sources of energetic charged particles for such inner radiation belt: the interaction of the Galactic Cosmic Rays (GCR) with the Saturn's atmosphere and rings, which due to CRAND process can produce the keV-MeV ions or electrons in the region, and the double charge exchange of the ENAs, coming from the middle magnetosphere, what can bring the keV ions to the region of our interest. Using the particles tracer, which was developed in our group, and GEANT4 software, we study in details those two processes. With a particle tracer we evaluate the GCR access to the Saturn atmosphere and rings. Simulation of the GCR trajectories allows to calculate the energy spectra of the arriving energetic particles, which is much more accurate, compare to the analytically predicted spectra using the Stoermer theory, since simulation includes effects of the ring shadow and non-dipolar processes in the magnetosphere. Using the GEANT4 software the penetration of the GCR through the matter of rings was simulated, and the production of secondaries particles was estimated. Finally, the motion of secondaries was simulated using the particles tracer, and evaluation of the energy spectrum of neutrons the decay of which leads to the production of final CRAND elements in the inner Saturnian radiation belts was done. We show that for inner radiation belt most energetic ions comes from GCR interaction with rings, it's penetration and from interaction of secondaries with Saturn's atmosphere. This simulation allows us to predict the fluxes of energetic ions and electrons, which particle detector MIMI/LEMMS onboard the Cassini can measure during the so-called "proximal

  2. 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...

  3. Radiation of complex and noisy sources within enclosures

    Science.gov (United States)

    Gradoni, Gabriele; Creagh, Stephen; Tanner, Gregor

    Predicting the radiation of complex electromagnetic sources inside semi-open cavities and resonators with arbitrary geometry is a challenging topic both for physics and for engineering. We have exploited a Perron-Frobenius operator to propagate field-field correlation functions of complex and extended sources in free-space. The formula is based on a phase-space picture of the electromagnetic field, using the Wigner distribution function, and naturally captures evanescent as well as diffracted waves. This approach can be extended to study the propagation of correlation functions within cavities, with the ray-dynamical map given by the geometry of the cord connecting a point of the boundary to another. While ray methods provide an efficient way to predict average values of the correlation matrix elements, the use of random matrix theory approaches allows efficient characterisation of statistical fluctuations around these averages. Universal relations are derived and tested in the presence of dissipation for quantum maps and billiard systems. The use of this formalism is discussed in the contexts of open systems with surface roughness. The theory and achieved results are of interest in the simulation of next-generation of wireless communications. Work supported by the UK Engineering and Physical Sciences Research Council.

  4. Accelerator Based Neutron Beams for Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yanch, Jacquelyn C.

    2003-04-11

    The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 10(sup 7) W/m(sup 2) with heat transfer coefficients of 10(sup 6)W/m(sup 2)-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and

  5. LIGHT SOURCE: Design of a new compact THz source based on Smith-Purcell radiation

    Science.gov (United States)

    Dai, Dong-Dong; Bei, Hua; Dai, Zhi-Min

    2009-06-01

    In recent years, people are dedicated to the research work of finding compact THz sources with high emission power. Smith-Purcell radiation is qualified for the possibility of coherent enhancement due to the effect of FEL mechanism. The compact experiment device is expected to produce hundreds mW level THz ray. The electron beam with good quality is provided under the optimized design of the electron gun. Besides, the grating is designed as an oscillator without any external feedbacks. While the beam passes through the grating surface, the beam bunching will be strong and the second harmonics enhancement will be evident, as is seen from the simulation results.

  6. Operation of the Metrology Light Source as a primary radiation source standard

    Directory of Open Access Journals (Sweden)

    Roman Klein

    2008-11-01

    Full Text Available The Metrology Light Source (MLS, the new electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB located in Berlin, is dedicated to metrology and technological developments in the UV and extreme UV spectral range as well as in the IR and THz region. The MLS can be operated at any electron beam energy between 105 and 630 MeV and at electron beam currents varying from 1 pA (one stored electron up to 200 mA. Moreover, it is optimized for the generation of coherent synchrotron radiation in the far IR/THz range. Of special interest for PTB is the operation of the MLS as a primary radiation source standard from the near IR up to the soft x-ray region. Therefore, the MLS is equipped with all the instrumentation necessary to measure the storage ring parameters and geometrical parameters needed for the calculation of the spectral photon flux according to the Schwinger theory with low uncertainty.

  7. 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.

  8. Novel particle and radiation sources and advanced materials

    Energy Technology Data Exchange (ETDEWEB)

    Mako, Frederick [FM Technologies, Inc. and Electron Technologies, Inc. (United States)

    2016-03-25

    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.

  9. Diffraction-enhanced imaging at the UK synchrotron radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Ibison, M. [Liverpool University, Liverpool (United Kingdom); Cheung, K.C. [C.L.R.C. Daresbury Laboratory, Keckwick Lane, Daresbury, Cheshire WA4 4AD (United Kingdom); Siu, K. [Monash University, Melbourne, Victoria (Australia); Hall, C.J. [C.L.R.C. Daresbury Laboratory, Keckwick Lane, Daresbury, Cheshire WA4 4AD (United Kingdom)]. E-mail: c.j.hall@dl.ac.uk; Lewis, R.A. [Monash University, Melbourne, Victoria (Australia); Hufton, A. [Christie Hospital, Manchester (United Kingdom); Wilkinson, S.J. [Cranfield University, R.M.C.S., Shrivenham (United Kingdom); Rogers, K.D. [Cranfield University, R.M.C.S., Shrivenham (United Kingdom); Round, A. [C.L.R.C. Daresbury Laboratory, Keckwick Lane, Daresbury, Cheshire WA4 4AD (United Kingdom)

    2005-08-11

    The Diffraction-Enhanced Imaging (DEI) system, which shares access to Beamline 7.6 on the Daresbury Synchrotron Radiation Source (SRS), is now in its third year of existence. The system was developed under a European Commission grant PHase Analyser SYstem (PHASY), won during the Fourth Framework. Typical applications continue to be the imaging of small biological specimens, using a beam of 12-17 keV after monochromation and up to 40 mm in width and 1-2 mm in height, although it is planned to investigate other materials as opportunity permits and time becomes available for more routine scientific use. Recent improvements have been made to the optical alignment procedure for setting up the station before imaging: a small laser device can now be set up to send a beam down the X-ray path through the four crystals, and a small photodiode, which has much better signal-to-noise characteristics than the ion chamber normally used for alignment, has been trailed successfully. A 3-D tomographic reconstruction capability has recently been developed and tested for DEI projection image sets, and will be applied to future imaging work on the SRS, in conjunction with volume visualization software. The next generation of DEI system, planned to operate at up to 60 keV on an SRS wiggler station, is in its design stage; it will feature much improved mechanics and mountings, especially for angular control, and a simplified alignment procedure to facilitate the necessary sharing of the SRS station.

  10. Diffraction-enhanced imaging at the UK synchrotron radiation source

    Science.gov (United States)

    Ibison, M.; Cheung, K. C.; Siu, K.; Hall, C. J.; Lewis, R. A.; Hufton, A.; Wilkinson, S. J.; Rogers, K. D.; Round, A.

    2005-08-01

    The Diffraction-Enhanced Imaging (DEI) system, which shares access to Beamline 7.6 on the Daresbury Synchrotron Radiation Source (SRS), is now in its third year of existence. The system was developed under a European Commission grant PHase Analyser SYstem (PHASY), won during the Fourth Framework. Typical applications continue to be the imaging of small biological specimens, using a beam of 12-17 keV after monochromation and up to 40 mm in width and 1-2 mm in height, although it is planned to investigate other materials as opportunity permits and time becomes available for more routine scientific use. Recent improvements have been made to the optical alignment procedure for setting up the station before imaging: a small laser device can now be set up to send a beam down the X-ray path through the four crystals, and a small photodiode, which has much better signal-to-noise characteristics than the ion chamber normally used for alignment, has been trailed successfully. A 3-D tomographic reconstruction capability has recently been developed and tested for DEI projection image sets, and will be applied to future imaging work on the SRS, in conjunction with volume visualization software. The next generation of DEI system, planned to operate at up to 60 keV on an SRS wiggler station, is in its design stage; it will feature much improved mechanics and mountings, especially for angular control, and a simplified alignment procedure to facilitate the necessary sharing of the SRS station.

  11. Crystal undulator as a new compact source of radiation

    Directory of Open Access Journals (Sweden)

    S. Bellucci

    2004-02-01

    Full Text Available Crystalline undulators with periodically deformed crystallographic planes offer coherent electromagnetic fields on the order of 1000 T and provide undulator period L in submillimeter range. We present an idea for creation of a crystalline undulator and report its realization. One face of a silicon crystal was given periodic microscratches (grooves by means of a diamond blade, with a period ranging from 0.1 to 0.5 mm in different samples. The x-ray tests of the crystal deformation have shown that a sinusoidal-like shape of crystalline planes goes through the bulk of the crystals. This opens up the possibility for experiments with high-energy particles channeled in the crystalline undulator, a new compact source of radiation. The first experiments on photon emission in the crystal undulator are in preparation at IHEP (Protvino with 2–15 GeV positrons and at LNF (Frascati with 500–800 MeV positrons, aiming to produce undulator photons in the range of 50–500 keV. The results of Monte Carlo simulations for the planned experiments are presented as well.

  12. 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.)

  13. 10 CFR 34.21 - Limits on external radiation levels from storage containers and source changers.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Limits on external radiation levels from storage... INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.21 Limits on external radiation levels from storage containers and source changers. The...

  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. Monitoring of {sup 60}Co radiation source parameters by optoelectronic instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Rogina, B.M.; Vojnovic, B. [Ruder Boskovic Institute, Zagreb (Costa Rica). Lab. for Stochastic Signals and Processes Research

    1995-12-31

    Problems of measuring the radiation dose level and determining the position of the {sup 60}Co radiation source rods are discussed. The continuous gamma ray source {sup 60}Co is used for various scientific and industrial, food and medical, irradiation applications with doses up to 10{sup 4} Gy. For radiation sensor the PCS optical fiber could be used. By radiation effects testing PCS fiber is found to have adequate sensitivity in the visible range up to 1.47 {times} 10{sup {minus}1} dB/kmGy at high exposure, up to 10{sup 3} Gy {sup 60}Co ionizing source irradiation. The position of the source rods is determined relative to the safety position, by the sensor linked with source position using mechanical transmission system. The digital position sensor based on the optoelectronic impulse source is developed, with accuracy {+-}1 mm for the whole vertical position change of the source and great exploitation resistance particularly to vibrations.

  16. 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.

  17. 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.

  18. Evaluation of the Timepix chip radiation hardness using a {sup 60}Co source

    Energy Technology Data Exchange (ETDEWEB)

    Čarná, Mária; Dučevová, Kateřina; Hejtmánek, Martin, E-mail: hejtmark@fzu.cz; Konček, Ondřej; Marčišovský, Michal

    2013-12-21

    Radiation damage is a widely studied topic for its effects on detectors and supporting electronics in various practical applications. Radiation hardness and stability of the detector properties are critical parameters in applications of semiconductor radiation detectors. The 0.25μm CMOS technology used in fabrication of the Medipix2 and Timepix chips provides high degree of inherent radiation hardness. We present the study of operational, detection and signal processing properties of the irradiated Timepix chip exposed to a high-flux {sup 60}Co source reaching the operational limits of the chip. -- Highlights: • Radiation hardness of pixel detector based on Medipix2 against {sup 60}Co has been performed. • The {sup Co} was used as a radiation source due to its usage in number of practical applications. • Systematic study of γ radiation of various energies on the detector systems is desired.

  19. Compact THz radiation source based on photocathode RF gun

    Institute of Scientific and Technical Information of China (English)

    URAKAWA; JunJi

    2011-01-01

    Terahertz (THz) science and technology have already become the research highlight at present. In this paper, we put forward a proposal to generate THz radiation at tens of MW peak power. As a result of the ultrafast laser and the high accelerating field of photocathode RF gun, we can generate and accelerate an electron beam to several MeV, of which the bunch length is less than sub-ps. When the short electron bunches are injected into the wiggler, THz radiation based on Coherent Synchrotron Radiation could be achieved with tens of MW peak power. The whole THz FEL facility can be scaled to the size of a tabletop.

  20. Recent status on cobalt-60 gamma ray radiation sources production and its application in China

    Science.gov (United States)

    Zhijian, Cao; Yunjiang, Song; Chunchua, Zhang; Maoling, Li

    1993-07-01

    This paper describes the recent status on Co-60 γ ray radiation sources production and its 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 can increase to 37 PBq(1 MCi) per year. The standard dimension of Co-60 γ ray radiation sources is φ 15×90 mm, the radioactivity of each sources is 370TBq - 740TBq(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 application, radiation sterilization of disposable medical supplies and food irradiation. The prospect of Co-60 γ ray radiation sources production and its application in China is good.

  1. A new source of radiation in single-bubble sonoluminescence

    Indian Academy of Sciences (India)

    MORTEZA PISHBINI; RASOUL SADIGHI-BONABI

    2017-04-01

    An unsolved challenge of sonoluminescence phenomenon is the mechanism of light emission at the moment of collapse. 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 havenumerically been studied to describe the Ar bubble radiation in water at the moment of collapse: (a) radiation from the Ar gas inside the bubble and (b) radiation from the thin layer of the surrounding fluid. The results indicatethat, contrary to the previous studies, the radiation from the water shell is dominant, and it is about one order of magnitude stronger than the radiation from the gas inside the bubble. This result can decrease the differencebetween the theoretical results and the previous experimental data. In addition, based on the role of acoustic pressure amplitude on the characteristics of single-bubble sonoluminescence, various parameters such as degree of ionization, gas pressure, temperature and power were calculated. The results are in excellent agreement with the reported experimental measurements.

  2. III. Biological effects of radiation from external and internal sources

    Energy Technology Data Exchange (ETDEWEB)

    Stone, R.S.

    1948-05-24

    This report focuses on the hemotological effects of total body irradiation from external and internal sources observed in patients treated for arthritis with radioactive phosphorus administered intravenously.

  3. Natural Sources of Radiation Exposure and the Teaching of Radioecology

    Science.gov (United States)

    Anjos, R. M.; Veiga, R.; Carvalho, C.; Sanches, N.; Estellita, L.; Zanuto, P.; Queiroz, E.; Macario, K.

    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-Muller detectors as survey meters for "in situ"…

  4. Natural Sources of Radiation Exposure and the Teaching of Radioecology

    Science.gov (United States)

    Anjos, R. M.; Veiga, R.; Carvalho, C.; Sanches, N.; Estellita, L.; Zanuto, P.; Queiroz, E.; Macario, K.

    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-Muller detectors as survey meters for "in situ"…

  5. Source parameters and radiation efficiency for intermediate-depth earthquakes in Northeast Japan

    NARCIS (Netherlands)

    Nishitsuji, Y.; Mori, J.

    2013-01-01

    We estimated source parameters of 216 intermediate-depth (65–150 km) earthquakes (Mw 4.0–7.0) in the Pacific slab beneath Japan along using Hi-net data. We made determinations of static stress drop, radiated energy and radiation efficiency, along with estimates of the whole path attenuation, to stud

  6. Source parameters and radiation efficiency for intermediate-depth earthquakes in Northeast Japan

    NARCIS (Netherlands)

    Nishitsuji, Y.; Mori, J.

    2013-01-01

    We estimated source parameters of 216 intermediate-depth (65–150 km) earthquakes (Mw 4.0–7.0) in the Pacific slab beneath Japan along using Hi-net data. We made determinations of static stress drop, radiated energy and radiation efficiency, along with estimates of the whole path attenuation, to stud

  7. Source parameters and radiation efficiency for intermediate-depth earthquakes in Northeast Japan

    NARCIS (Netherlands)

    Nishitsuji, Y.; Mori, J.

    2013-01-01

    We estimated source parameters of 216 intermediate-depth (65–150 km) earthquakes (Mw 4.0–7.0) in the Pacific slab beneath Japan along using Hi-net data. We made determinations of static stress drop, radiated energy and radiation efficiency, along with estimates of the whole path attenuation, to

  8. Localization of non-stationary sources of electromagnetic radiation with the aid of phasometry

    Science.gov (United States)

    Mersov, G. A.

    1978-01-01

    The possibility of localizing sources of electromagnetic radiation by measurement of the time of passage of the radiation or the measurement of its phase at various points of cosmic space, at which are located satellite observatories is examined. Algorithms are proposed for localization using two, three, and four astronomical observatories. The precision of the localization and several partial results of practical significance are deduced.

  9. Localization of the gamma-radiation sources using the gamma-visor

    OpenAIRE

    Ivanov Kirill E.; Ponomaryev-Stepnoi Nikolai N.; Stepennov Boris S.; Teterin Yury A.; Teterin Anton Y.; Kharitonov Vladimir V.

    2008-01-01

    The search of the main gamma-radiation sources at the site of the temporary storage of solid radioactive wastes was carried out. The relative absorbed dose rates were measured for some of the gamma-sources before and after the rehabilitation procedures. The effectiveness of the rehabilitation procedures in the years 2006-2007 was evaluated qualitatively and quantitatively. The decrease of radiation background at the site of the temporary storage of the solid radioactive wastes after the rehab...

  10. 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.

  11. Emission of gravitational radiation from ultra-relativistic sources

    CERN Document Server

    Segalis, E B; Segalis, Ehud B.; Ori, Amos

    2001-01-01

    Recent observations suggest that blobs of matter are ejected with ultra-relativistic speeds in various astrophysical phenomena such as supernova explosions, quasars, and microquasars. In this paper we analyze the gravitational radiation emitted when such an ultra-relativistic blob is ejected from a massive object. We express the gravitational wave by the metric perturbation in the transverse-traceless gauge, and calculate its amplitude and angular dependence. We find that in the ultra-relativistic limit the gravitational wave has a wide angular distribution, like $1+\\cos\\theta$. The typical burst's frequency is Doppler shifted, with the blue-shift factor being strongly beamed in the forward direction. As a consequence, the energy flux carried by the gravitational radiation is beamed. In the second part of the paper we estimate the anticipated detection rate of such bursts by a gravitational-wave detector, for blobs ejected in supernova explosions. Dar and De Rujula recently proposed that ultra-relativistic bl...

  12. Terahertz radiation source using an industrial electron linear accelerator

    CERN Document Server

    Kalkal, Yashvir

    2015-01-01

    High power ($\\sim 100$ kW) industrial electron linear accelerators (linacs) are used for irradiation applications 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 be first passed through an undulator to generate powerful terahertz (THz) radiation, and the spent electron beam coming out of the undulator can still be used for industrial applications. This will enhance the utilisation of a high power industrial linac. We have performed calculation of spontaneous emission in the undulator to show that for typical parameters, continuous terahertz radiation having power of the order of $\\mu$W can be produced, which may be useful for many scientific applications.

  13. Multiple Detector Optimization for Hidden Radiation Source Detection

    Science.gov (United States)

    2015-03-26

    that can make the problem much more complex. The capability to discriminate between background and SNM radiation in a timely manner requires the...The tolerance was reduced again by approximately two orders of magnitude due to the overlap of detectors. It appears as though the detectors are now...develop a model to deduce an employment /emplacement strategy for optimal detector placement based on the amount of devices available. The 2

  14. 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)

  15. Radiation Tolerant Low Power Precision Time Source Project

    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...

  16. Polycapillary X-ray lens for the secondary focusing Beijing synchrotron radiation source

    Institute of Scientific and Technical Information of China (English)

    Li Yu-De; Lin Xiao-Yan; Liu Shi-Gang; He Jin-Long; Guo Fei; Sun Tian-Xi; Liu Peng

    2013-01-01

    According to intensity distribution of the synchrotron radiation source focused by a toroidal mirror at the Beijing synchrotron radiation biological macromolecule station,theoretical modeling of the Beijing synchrotron radiation source is developed for capillary optics.Using this theoretical modeling,the influences of the configuration curve of the polycapillary X-ray lens on transmission efficiency and working distance are analyzed.The experimental results of the transmission efficiency and working distance at the biological macromolecule station are in good agreement with the theoretical results.

  17. 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.)

  18. The Radiation Dose Determination of the Pulsed X-ray Source

    Science.gov (United States)

    Miloichikova, I.; Stuchebrov, S.; Zhaksybayeva, G.; Wagner, A.

    2014-10-01

    In this paper the radiation dose measurement technique of the pulsed X-ray source RAP-160-5 is described. The dose rate measurement results from the pulsed X-ray beams at the different distance between the pulsed X-ray source focus and the detector obtained with the help of the thermoluminescent detectors DTL-02, the universal dosimeter UNIDOS E equipped with the plane-parallel ionization chamber type 23342, the dosimeter-radiometer DKS-96 and the radiation dosimeter AT 1123 are demonstrated. The recommendations for the dosimetry measurements of the pulsed X-ray generator RAP-160-5 under different radiation conditions are proposed.

  19. The spacetime outside a source of gravitational radiation: The axially symmetric null fluid

    CERN Document Server

    Herrera, L; Ospino, J

    2016-01-01

    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 spacetimes. 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.

  20. A biotechnological project with a gamma radiation source of 100,000 Ci

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, J.H.; Smolko, E.E. (Comision Nacional de Energia Atomica, Buenos Aires (Argentina))

    1990-01-01

    A project for the production of radiovaccines and other bio-medical products is presented which includes a radiation facility provided with a gamma ray source equivalent to 100,000 Ci of Co-60. The whole process incorporates novel basic features in virus production and inactivation steps. The former is carried out in animals previously subjected to immunodepression through electromagnetic radiation. The latter is obtained at low temperatures by using either electromagnetic or particle radiations. A vaccine manufacture process is shown to illustrate the utilization of ionizing radiations to obtain a foot and mouth disease virus (FMDV) vaccine with good antigenic quality and low cost. (author).

  1. Characterization methods for an accelerator based fast-neutron facility

    Science.gov (United States)

    Franklyn, C.; Daniels, G. C.

    2012-02-01

    A fast neutron facility provides a number of complexities in both detection and shielding, the latter arising not only due to uncertainty in the behaviour of the scattered radiation (neutron and gamma-rays) from a fast neutron source, but also on shielding requirements that have to take into account internal and external factors, such as dose limitations, space availability for implementing bulky shielding and secondary interactions of the radiation with materials. This has possible influence on experimental measurements with a low signal to noise ratio. This paper reports on some of the investigations performed at a RFQ accelerator facility generating > 1011 neutrons per second with energies up to 14 MeV, which are used to perform fast neutron radiography studies. Areas highlighted are the neutron cross section libraries, where important data needs to be reviewed or updated.

  2. Radiation force on absorbing targets and power measurements of a high intensity focused ultrasound (HIFU) source

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the analytic expressions for the radiated field of a circular concave piston given by Hasegawa et al.,an integral for calculation of the radiation force on a plane absorbing target in a spherically focused field is derived.A general relation between acoustic power P and normal radiation force Fn is obtained under the condition of kr 1.Numerical computation is carried out by using the symbolic computation program for practically focused sources and absorbing circular targets.The results show that,for a given source,there is a range of target positions where the radiation force is independent of the target’s position under the assumption that the contribution of the acoustic field behind the target to the radiation force can be neglected.The experiments are carried out and confirm that there is a range of target positions where the measured radiation force is basically independent of the target’s position even at high acoustic power (up to 700 W).It is believed that when the radiation force method is used to measure the acoustic power radiated from a focused source,the size of the target must be selected in such a way that no observable sound can be found in the region behind the target.

  3. A Sensitivity Study on Radiation Dose of 500W RTPV having Different Source Shapes

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, Seong Jae; Hong, Ser Gi [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Radioisotope Thermoelectric Generators (RTG) has been considered as a power supply system for long-lived operation in space. RTG is an essentially nuclear battery that converts the heat resulted from the radioactive decay into electricity. RTG has the advantage of high energy density and long life operation because of the very long half-life of the radioisotopes. However, RTG systems have relatively low thermoelectric energy conversion efficiency of 3-7%. In this work, a sensitivity study on the total radiation dose was performed for 500W RTPVs having different source configurations. In particular, comparative shielding analysis using two different types of source design (a cubic source type and cylindrical sources type) were performed to show their relative performances. The results show that the RTPV(the cubic homogeneous source type and the cylindrical heterogeneous source type) device using the cylindrical sources type has lower dose values by 6-11% depending on the packing factor at the measurement cell than the RTPV device using the cubic source type. Also, we investigated the effect of the compactness of four cylindrical sources on the radiation dose. The results showed that the loosely packed sources give lower total radiation dose than the closely packed sources.

  4. Prospects for the study of biological systems with high power sources of terahertz radiation.

    Science.gov (United States)

    Weightman, Peter

    2012-10-01

    The emergence of intense sources of terahertz radiation based on lasers and electron accelerators has considerable potential for research on biological systems. This perspective gives a brief survey of theoretical work and the results of experiments on biological molecules and more complex biological systems. Evidence is accumulating that terahertz radiation influences biological systems and this needs to be clarified in order to establish safe levels of human exposure to this radiation. The use of strong sources of terahertz radiation may contribute to the resolution of controversies over the mechanism of biological organization. However the potential of these sources will only be realized if they are accompanied by the development of sophisticated pump-probe and multidimensional experimental techniques and by the study of biological systems in the controlled environments necessary for their maintenance and viability.

  5. Synchrotron radiation as a light source in confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    van der Oord, C.J.R.; Gerritsen, H.C.; Levine, Y.K. (University of Utrecht, P.O. Box 80.000, 3508 TA Utrecht (Netherlands)); Myring, W.J.; Jones, G.R.; Munro, I.H. (Daresbury Laboratory (United Kingdom))

    1992-01-01

    The optical properties of a confocal scanning microscope that was designed to utilize a synchrotron as light source are presented. The usable spectral range is from 200 nm up to 700 nm. Using 325-nm laser light, it is shown that the lateral resolution is about 125 nm, and the axial resolution better than 250 nm. After transport of the microscope from Utrecht to the Daresbury Synchrotron Source, 200-nm excitation can be applied, and the lateral resolution will drop to below 100 nm.

  6. A Far-Infrared FEL for the Radiation Source ELBE

    CERN Document Server

    Seidel, W; Lehnert, U; Michel, P; Schlenk, R; Willkommen, U; Wohlfarth, D; Wünsch, R

    2005-01-01

    After successfully commissioning the mid-infrared FEL (U27) and adjoining a second accelerator unit (up to 35 MeV) at ELBE we have modified our plan how to produce radiation in the far infrared.To ensure the continuous variation of the wavelength up to 150 microns we want to complement the U27 undulator by a permanent magnet undulator with a period of 100 mm (U100). The minimum gap of 24 mm and the hybrid construction consisting of Sm/Co magnets and soft iron poles ensures sufficient radiation resistance and allows rms undulator parameters up to 2.7. The large field variation allows us to cover the whole wavelength range by only two different electron energies (e.g. 20 and 35 MeV). To reduce the transverse beam size we use a partial waveguide which is 10 mm high and wide enough to allow free propagation in horizontal direction. It spans from the last quadrupole in front of the undulator up to the downstream mirror and is somewhat longer than 8 m. To minimize the coupling losses between free propagation and th...

  7. Localization of the gamma-radiation sources using the gamma-visor

    Directory of Open Access Journals (Sweden)

    Ivanov Kirill E.

    2008-01-01

    Full Text Available The search of the main gamma-radiation sources at the site of the temporary storage of solid radioactive wastes was carried out. The relative absorbed dose rates were measured for some of the gamma-sources before and after the rehabilitation procedures. The effectiveness of the rehabilitation procedures in the years 2006-2007 was evaluated qualitatively and quantitatively. The decrease of radiation background at the site of the temporary storage of the solid radioactive wastes after the rehabilitation procedures allowed localizing the new gamma-source.

  8. Internet as a Source of Misconception: "Radiation and Radioactivity"

    Science.gov (United States)

    Acar Sesen, Burcin; Ince, Elif

    2010-01-01

    The purpose of this study is to examine students' usage styles of the Internet for seeking information and to investigate whether information obtained from the Internet is a source of misconceptions. For this reason, a two-stage study was conducted. At the first stage, a questionnaire was developed to get information about students' Internet usage…

  9. Dazzling new light source opens at Stanford synchrotron radiation laboratory

    CERN Multimedia

    2004-01-01

    SPEAR3, the Stanford Positron Electron Asymmetric Ring, was formally opened at a dedication ceremony at the Stanford Linear Accelerator Center on Jan. 29. It incorporates the latest technology to make it competitive with the best synchrotron sources in the world (1/2 page)

  10. Development of lowenergy accelerator-based production of medical isotopes

    OpenAIRE

    Radcliffe, Naomi; Barlow, Roger; Cywinski, Robert; Beasley, P.

    2013-01-01

    Here we present methods for production of new and existing isotopes for SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) imaging using accelerator-based systems. Such isotopes are already widely used in medical diagnostics and research, and there is constant development of new drugs and isotopes. However the main production method for 99mTc, is currently in research reactors and is at risk due to scheduled and unscheduled shut downs. Therefore, a low c...

  11. Admixtures in Spent Plutonium Sources and Gamma-Radiation

    Directory of Open Access Journals (Sweden)

    Inga Pelanytė

    2011-04-01

    Full Text Available The isotopic composition of several spent smoke detectors containing plutonium has been investigated. The article also presents the calculated results of 241Am and 241Pu activities in smoke detectors. The received values vary from (0.934±0.028 MBq to (91.2±4.6 MBq. The eguivalent dose rate of the established gamma radiation vary from 220 nSv/h to 500 nSv/h. A dose caused by artificial radionuclides in spent smoke detectors was evaluated and compared in the article. It has been found out that due to smoke detectors, an annual dose varies from 0.06 mSv to 0.31 mSv. Article in Lithuanian

  12. Radiative feedback and cosmic molecular gas: the role of different radiative sources

    CERN Document Server

    Maio, U; De Lucia, G; Borgani, S

    2016-01-01

    We present results from multifrequency radiative hydrodynamical chemistry simulations addressing primordial star formation and related stellar feedback from various populations of stars, stellar energy distributions (SEDs) and initial mass functions. Spectra for massive stars, intermediate-mass stars and regular solar-like stars are adopted over a grid of 150 frequency bins and consistently coupled with hydrodynamics, heavy-element pollution and non-equilibrium species calculations. Powerful massive population III stars are found to be able to largely ionize H and, subsequently, He and He$^+$, causing an inversion of the equation of state and a boost of the Jeans masses in the early intergalactic medium. Radiative effects on star formation rates are between a factor of a few and 1 dex, depending on the SED. Radiative processes are responsible for gas heating and photoevaporation, although emission from soft SEDs has minor impacts. These findings have implications for cosmic gas preheating, primordial direct-c...

  13. UV radiation sources operating in an abnormal microdischarge regime

    Science.gov (United States)

    Starostin, S. A.; Mitko, S. V.; Peters, P. J. M.; Boller, K. J.; Udalov, Yu. B.

    2002-10-01

    Recently we proposed a new design approach for microdischarge plasma sources and microdischarge arrays [1]. The major improvement comes from the fact that the ceramic dielectric layer is sintered directly on the metal cathode. The discharge channels are drilled in the dielectric layer mechanically or by laser. This design approach excludes the undesirable cathode spot spread, which usually occurs if dielectric is mechanically pressed on the cathode surface. Another advantage is a possibility of efficient cooling. The electrical characteristics of a single microdischarge and microdischarge array operating in abnormal regime were investigated in different gas mixtures (He, Ar, Xe, He-Ar-Xe, He-Xe-HCl) at different gas pressures and configurations of the discharge set-up. The studied set-up allows to achieve discharge voltages up to 2kV in continuous wave DC mode at gas pressures of 100-200 mbar in He or He-Xe gas mixtures. The obtained results indicate that this kind of discharge can be considered as a low-energy electron-beam source. It can be used for efficient pumping of gas lasers (for instance atomic Xe) or for large area planar VUV light sources based on excimers with relatively high excitation threshold (for instance He2 or Ne2 dimers). 1. RU.Patent N^o 2172573

  14. Pushing the Frontiers of Science with Synchrotron Radiation: BESAC Panel on DOE Synchrotron Radiation Sources and Science

    Science.gov (United States)

    Birgeneau, Robert J.

    1998-04-01

    During 1997 a panel empowered by the Basic Energy Sciences Advisory Committee and chaired by the speaker carried out a comprehensive review of the four DOE synchrotron sources, the ALS, APS, NSLS and SSRL^1.(Report of Basic Energy Sciences Advisory Committee Panel on DOE Synchrotron Radiation Sources and Science, November 1997) We also reviewed the science and technology, past and present, carried out at these facilities. This included the areas of materials research, surface science, polymers and other forms of soft condensed matter, atomic, optical, and molecular physics and chemistry, molecular environmental science, the geosciences and structural biology. We also considered more cursorily ongoing and proposed research on fourth generation sources. The most straightforward and most important conclusion of this study is that over the past 20 years in the United States synchrotron radiation research has evolved from an esoteric endeavor practiced by a small number of scientists primarily from the fields of solid state physics and surface science to a mainstream activity which provides essential information in all of the above fields. The user community at U.S. synchrotron facilities continues to grow exponentially, having reached more than 4000 on-site users annually in FY97. The research carried out at the four DOE synchrotron sources is both very broad and often exceptionally deep. We will review the results of this study with emphasis on the current science and anticipated future research carried out at modern synchrotron sources.

  15. Emittance Adapter for a Diffraction Limited Synchrotron Radiation Source

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alexander Wu; /SLAC; Raimondi, Pantaleo; /Frascati

    2012-03-01

    We investigate the possibility of reaching very small horizontal and vertical emittances inside an undulator in a storage ring, by means of a local exchange of the apparent horizontal and vertical emittances, performed with a combination of skew quadrupoles and one solenoid in a dedicated insertion line in the storage ring. The insertion leaves the ring parameters and its optical properties unaffected. This scheme could greatly relax the emittance requirements for a diffraction limited synchrotron light source. The lattice derivation and design is described.

  16. Compact XUV excimer radiation sources and their application

    Science.gov (United States)

    Fedenev, Andrei V.; Morozov, Andrei; Wieser, Jochen; Ulrich, Andreas

    2004-05-01

    Low energy electron beam excitation of dense helium and neon was used for light production in the extreme ultraviolet (XUV) wavelength range. The entire system was completely filled with the working gas avoiding the use of vacuum equipment for light production, propagation and detection. Emission spectra from He and Ne are dominated by the second continua with peak intensities at 80 and 83 nm, respectively. The hydrogen Lyman-α line was observed as the dominant impurity line. This XUV light source was used for transmission measurements of LiF near its absorption edge.

  17. Multi-source driven capillary plane radiation air conditioning system

    Science.gov (United States)

    Hu, Juanjuan; Qu, Mofeng; Wang, Huasheng; Ni, Shiyao

    2017-08-01

    A new absorption refrigeration system, which is driven by solar energy, biomass energy and geothermal energy simultaneously, was designed with capillaries as its radiation surface. Likewise, variations of water temperature in the capillaries with the change in both time and its flow rate were experimentally researched as well as how COP of the system varies with the surrounding temperature. The following conclusions have been obtained: Common refrigeration demand can be met by the system after its operation in 1 hour; with the increase in water flow rate in the capillaries, its temperature, which drops down after an increase, gets its peak value at the flow rate of 4.5-5.5 L/min; COP of the system decreases with the rise of surrounding temperature, thus it's better to keep it from direct sunlight. With the utilization of natural energy and the structure of capillaries, the system's advantages in simple structure, low cost, environment-friendly working process and nice performance lead to promising application prospects, especially in residence refrigeration in countryside.

  18. The angular dependence of an Si energy deposition spectrometer response at several radiation sources

    CERN Document Server

    Spurny, F; Trompier, F

    2005-01-01

    An MDU-Liulin spectrometer based on an Si-diode was mainly used during the last few years with the goal to use them for measurements onboard aircraft. To investigate its ability to obtain such measurements, the detector was tested in some radiation reference fields, like /sup 60/Co and other photon beams, neutrons of an AmBe and /sup 252/Cf sources and in high-energy radiation fields at CERN. Due to the high geometrical asymmetry of the Si-diode semiconductor, an angular dependence of the response would be expected. This work presents analyses and discusses the results of angular dependence studies obtained at the different radiation sources mentioned. It was found that these angular dependences vary with the type and energy of radiation. The influence of these variations on the use as a dosimeter onboard aircraft is also studied and discussed.

  19. High power bremsstrahlung X-ray source for radiation processing

    Science.gov (United States)

    Yotsumoto, K.; Sunaga, H.; Tanaka, S.; Kanazawa, T.; Agematsu, T.; Tanaka, R.; Yoshida, K.; Taniguchi, S.; Sakamoto, I.; Tamura, N.

    The high power X-ray irradiation facility designed for the sterilization of medical appliances is described. The X-ray source consists of the 5 MeV, 300 kW Cockcroft Walton type of electron accelerator and the water cooled tantalum target. Conditions necessary for designing the X-ray target are conversion efficiency from electron beam to X-ray, thermal conductivity, readiness for machining and cost of the material. The conversion efficiency was determined through the Monte Carlo type calculation and obtained as 10.8 % for 3.667 g/cm 2 thickness (1 csda range) of tantalum target. In order to obtain the data on the source design, experiments have been carried out at the JAERI TAKASAKI 2 MeV, 60 kW Cockcroft-Walton type of electron accelerator equipped with a tantalum target. The size of package and the speed of conveyor was determined through the calculation of the absorbed dose distribution in the irradiated medium and the utilization efficiency.

  20. Electromagnetic radiation from filamentary sources in the presence of axially magnetized cylindrical plasma scatterers

    Energy Technology Data Exchange (ETDEWEB)

    Es’kin, V. A.; Ivoninsky, A. V.; Kudrin, A. V., E-mail: kud@rf.unn.ru; Popova, L. L. [Lobachevsky University (Russian Federation)

    2017-02-15

    Electromagnetic radiation from filamentary electric-dipole and magnetic-current sources of infinite length in the presence of gyrotropic cylindrical scatterers in the surrounding free space is studied. The scatterers are assumed to be infinitely long, axially magnetized circular plasma columns parallel to the axis of the filamentary source. The field and the radiation pattern of each source are calculated in the case where the source frequency is equal to one of the surface plasmon resonance frequencies of the cylindrical scatterers. It is shown that the presence of even a single resonant magnetized plasma scatterer of small electrical radius or a few such scatterers significantly affects the total fields of the filamentary sources, so that their radiation patterns become essentially different from those in the absence of scatterers or the presence of isotropic scatterers of the same shape and size. It is concluded that the radiation characteristics of the considered sources can efficiently be controlled using their resonance interaction with the neighboring gyrotropic scatterers.

  1. Measurement of an image jitter of an extended incoherent radiation source

    Science.gov (United States)

    Lukin, V. P.; Nosov, V. V.

    2017-06-01

    A scheme of an image jitter measuring device, which uses an extended incoherent source as a radiation source, is presented. The efficiency of the measuring device is analysed analytically and numerically in order to justify the operation of the adaptive optical system that does not require special creation or formation of a reference source. The features of the formed image of incoherent radiation are considered, in particular from the point of view of its possible application for measuring the phase fluctuations of optical waves propagating in a turbulent atmosphere (the adaptive system monitors the image of a self-luminous object illuminated by extraneous sources). The possibility of utilising a Shack-Hartmann wavefront sensor in adaptive systems using the image of an arbitrary object (or its fragment) as a reference source is shown.

  2. Hilbert Spectral Analysis of THz Radiation Sources by High-Tc Josephson Detectors

    Science.gov (United States)

    Divin, Yuriy; Lyatti, Matvey; Poppe, Ulrich

    A Hilbert spectrum analyzer was developed and characterized with monochromatic radiation sources at the frequency range from 30 GHz to 1 THz. The analyzer was based on a high-Tc frequency-selective Josephson detector and cooled to temperatures of 60-80K by a Stirling cryocooler. The instrumental function of the spectrum analyzer was shown to be of Lorentz type and within accuracy up to 0.1% without any harmonic and subharmonic contributions. Spectral characterization of THz sources, based on frequency multiplication of input microwave radiation by Schottky diodes, was demonstrated for input frequencies from 10 to 20 GHz with a total scanning time as low as 50 ms per scan. The developed Hilbert spectrum analyzer might be considered as a compact and high-speed substitute of conventional Fourier spectrometers, which are used for characterization of THz radiation sources in combination with liquid-helium-cooled silicon bolometers.

  3. Projection of needs for gamma radiation sources and other radioisotopes and assessment of alternatives for providing radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Ross, W.A.; Jensen, G.A.; Clark, L.L.; Eakin, D.E.; Jarrett, J.H.; Katayama, Y.B.; McKee, R.W.; Morgan, L.G.; Nealey, S.M.; Platt, A.M.; Tingey, G.L.

    1989-06-01

    Pacific Northwest Laboratory reviewed the projected uses and demands for a variety of nuclear byproducts. Because the major large-scale near-term demand is for gamma irradiation sources, this report concentrates on the needs for gamma sources and evaluates the options for providing the needed material. Projections of possible growth in the irradiation treatment industry indicate that there will be a need for 180 to 320 MCi of /sup 60/Co (including /sup 137/Cs equivalent) in service in the year 2000. The largest current and projected use of gamma irradiation is for the sterilization of medical devices and disposable medical supplies. Currently, 40% of US disposable medical products are treated by irradiation, and within 10 years it is expected that 90% will be treated in this manner. Irradiation treatment of food for destruction of pathogens or parasites, disinfestation, or extension of allowable storage periods is estimated to require an active inventory of 75 MCi of /sup 60/Co-equivalent gamma source in about a decade. 90 refs., 7 figs., 25 tabs.

  4. Development and construction of a neutron beam line for accelerator-based boron neutron capture synovectomy.

    Science.gov (United States)

    Gierga, D P; Yanch, J C; Shefer, R E

    2000-01-01

    A potential application of the 10B(n, alpha)7Li nuclear reaction for the treatment of rheumatoid arthritis, termed Boron Neutron Capture Synovectomy (BNCS), is under investigation. In an arthritic joint, the synovial lining becomes inflamed and is a source of great pain and discomfort for the afflicted patient. The goal of BNCS is to ablate the synovium, thereby eliminating the symptoms of the arthritis. A BNCS treatment would consist of an intra-articular injection of boron followed by neutron irradiation of the joint. Monte Carlo radiation transport calculations have been used to develop an accelerator-based epithermal neutron beam line for BNCS treatments. The model includes a moderator/reflector assembly, neutron producing target, target cooling system, and arthritic joint phantom. Single and parallel opposed beam irradiations have been modeled for the human knee, human finger, and rabbit knee joints. Additional reflectors, placed to the side and back of the joint, have been added to the model and have been shown to improve treatment times and skin doses by about a factor of 2. Several neutron-producing charged particle reactions have been examined for BNCS, including the 9Be(p,n) reaction at proton energies of 4 and 3.7 MeV, the 9Be(d,n) reaction at deuteron energies of 1.5 and 2.6 MeV, and the 7Li(p,n) reaction at a proton energy of 2.5 MeV. For an accelerator beam current of 1 mA and synovial boron uptake of 1000 ppm, the time to deliver a therapy dose of 10,000 RBEcGy ranges from 3 to 48 min, depending on the treated joint and the neutron producing charged particle reaction. The whole-body effective dose that a human would incur during a knee treatment has been estimated to be 3.6 rem or 0.75 rem, for 1000 ppm or 19,000 ppm synovial boron uptake, respectively, although the shielding configuration has not yet been optimized. The Monte Carlo design process culminated in the construction, installation, and testing of a dedicated BNCS beam line on the high

  5. Radiative feedback and cosmic molecular gas: the role of different radiative sources

    Science.gov (United States)

    Maio, Umberto; Petkova, Margarita; De Lucia, Gabriella; Borgani, Stefano

    2016-08-01

    We present results from multifrequency radiative hydrodynamical chemistry simulations addressing primordial star formation and related stellar feedback from various populations of stars, stellar spectral energy distributions (SEDs) and initial mass functions. Spectra for massive stars, intermediate-mass stars and regular solar-like stars are adopted over a grid of 150 frequency bins and consistently coupled with hydrodynamics, heavy-element pollution and non-equilibrium species calculations. Powerful massive Population III stars are found to be able to largely ionize H and, subsequently, He and He+, causing an inversion of the equation of state and a boost of the Jeans masses in the early intergalactic medium. Radiative effects on star formation rates are between a factor of a few and 1 dex, depending on the SED. Radiative processes are responsible for gas heating and photoevaporation, although emission from soft SEDs has minor impacts. These findings have implications for cosmic gas preheating, primordial direct-collapse black holes, the build-up of `cosmic fossils' such as low-mass dwarf galaxies, the role of active galactic nuclei during reionization, the early formation of extended discs and angular-momentum catastrophe.

  6. Robust and Scalable Tracking of Radiation Sources with Cheap Binary Proximity Sensors

    CERN Document Server

    Baidoo-Williams, Henry E

    2016-01-01

    We present a new approach to tracking of radiation sources moving on smooth trajectories which can be approximated with piece-wise linear joins or piece-wise linear parabolas. We employ the use of cheap binary proximity sensors which only indicate when a radiation source enters and leaves its sensing range. We present two separate cases. The first is considering that the trajectory can be approximated with piece-wise linear joins. We develop a novel scalable approach in terms of the number of sensors required. Robustness analysis is done with respect to uncertainties in the timing recordings by the radiation sensors. We show that in the noise free case, a minimum of three sensors will suffice to recover one piece of the linear join with probability one, even in the absence of knowledge of the speed and statistics of the radiation source. Second, we tackle a more realistic approximation of trajectories of radiation sources -- piece-wise parabolic joins -- and show that no more than six sensors are required in ...

  7. Influence of Size of Source Effect on Accuracy of LWIR Radiation Thermometers

    Directory of Open Access Journals (Sweden)

    Cywiak David

    2016-12-01

    Full Text Available Determining the size of source effect of a radiation thermometer is not an easy task and manufacturers of these thermometers usually do not indicate the deviation to the measured temperature due to this effect. It is one of the main uncertainty components when measuring with a radiation thermometer and it may lead to erroneous estimation of the actual temperature of the measured target. We present an empiric model to estimate the magnitude of deviation of the measured temperature with a long-wavelength infrared radiation thermometer due to the size of source effect. The deviation is calculated as a function of the field of view of the thermometer and the diameter of the radiating source. For thermometers whose field of view size at 90% power is approximately equal to the diameter of the radiating source, it was found that this effect may lead to deviations of the measured temperature of up to 6% at 200ºC and up to 14% at 500ºC. Calculations of the temperature deviation with the proposed model are performed as a function of temperature and as a function of the first order component of electrical signal.

  8. Prospects of extreme ultraviolet radiation sources based on microwave discharge for high-resolution lithography

    Science.gov (United States)

    Abramov, I. S.; Gospodchikov, E. D.; Shalashov, A. G.

    2017-07-01

    In this paper, inspired by the success of recent experiments, we discuss a new possible type of sources of extreme ultraviolet radiation for the semiconductor industry, based on the radiating plasma with multiply charged ions supported in a mirror magnetic trap by high-power microwaves. We propose a simple theory that describes the main features of such source, perform modeling for a wide range of plasma parameters and magnetic configurations, compare the results to the existing experimental data, and study the prospects of the new scheme in present technological circumstances.

  9. Partial coherence and imperfect optics at a synchrotron radiation source modeled by wavefront propagation

    Science.gov (United States)

    Laundy, David; Alcock, Simon G.; Alianelli, Lucia; Sutter, John P.; Sawhney, Kawal J. S.; Chubar, Oleg

    2014-09-01

    A full wave propagation of X-rays from source to sample at a storage ring beamline requires simulation of the electron beam source and optical elements in the beamline. The finite emittance source causes the appearance of partial coherence in the wave field. Consequently, the wavefront cannot be treated exactly with fully coherent wave propagation or fully incoherent ray tracing. We have used the wavefront code Synchrotron Radiation Workshop (SRW) to perform partially coherent wavefront propagation using a parallel computing cluster at the Diamond Light Source. Measured mirror profiles have been used to correct the wavefront for surface errors.

  10. Performance of light sources and radiation sensors under low gravity realized by parabolic airplane flights

    Science.gov (United States)

    Hirai, Hiroaki; Kitaya, Yoshiaki; Hirai, Takehiro

    A fundamental study was conducted to establish an experimental system for space farming. Since to ensure optimal light for plant cultivation in space is of grave importance, this study examined the performance of light sources and radiation sensors under microgravity conditions created during the parabolic airplane flight. Three kinds of light sources, a halogen bulb, a fluorescent tube, and blue and red LEDs, and ten models of radiation sensors available in the market were used for the experiment. Surface temperature of the light sources, output signals from the radiation sensors, spectroscopic characteristics were measured at the gravity levels of 0.01, 1.0 and 1.8 G for 20 seconds each during parabolic airplane flights. As a result, the performance of the halogen lamp was affected the most by the gravity level among the three light sources. Under the microgravity conditions which do not raise heat convection, the temperature of the halogen lamp rose and the output of the radiation sensors increased. Spectral distributions of the halogen lamp indicated that peak wavelength appeared the highest at the level of 0.01G, which contributed to the increase in light intensity. In the case of red and blue LEDs, which are promising light sources in space farming, the temperature of both LED chips rose but irradiance from red LED increased and that from blue LED decreased under microgravity conditions due to the different thermal characteristics.

  11. A broadband excimer source of visible radiation with barrier discharge pumping

    Science.gov (United States)

    Malinin, A. N.; Polyak, A. V.

    2003-12-01

    We investigate the characteristics of a broadband cylindrical excimer source of visible radiation with a surface area of 230 cm2 excited by a pulse-periodic barrier discharge based on multicomponent mixtures (mercury diiodide and dibromide with helium and admixtures of molecular nitrogen and xenon). The working mixture components were excited by a pulse-periodic (pulse repetition rate 500 5000 Hz, pulse duration ˜150 ns) barrier discharge. We detected radiation from excimer HgI* and HgBr* molecules, the second positive system of molecular nitrogen, and mercury and xenon atoms. The amplitude, duration, and trailing edge of the radiation pulses in the HgI2:HgBr2:Xe:He and HgI2: HgBr2:N2:He mixtures with admixtures of xenon and molecular nitrogen were found to change compared to the HgI2:HgBr2:He mixture. The optimal partial pressure of helium lies within the range 162 195 kPa. The most intense radiation from HgI* and HgBr* molecules (in a ratio of more than 3: 1) is observed in the HgI2:HgBr2: Xe:He mixture. The mean and pulse radiation powers are 45 W and 93 kW, respectively, at a pumping pulse repetition rate of 5000 Hz and an efficiency of 30%. We discuss the spectral and temporal characteristics of the radiation source and the dependence of the radiation intensity of excimer molecules of mercury monoiodide and monobromide on the partial pressures of xenon and nitrogen. We point out that the radiation source is of considerable interest for applications in biotechnology and medicine.

  12. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    Energy Technology Data Exchange (ETDEWEB)

    Debus, Alexander

    2012-09-06

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  13. SiC detectors for radiation sources characterization and fast plasma diagnostic

    Science.gov (United States)

    Cannavò, A.; Torrisi, L.

    2016-09-01

    Semiconductor detectors based on SiC have been investigated to characterize the radiations (photons and particles) emitted from different sources, such as radioactive sources, electron guns, X-ray tubes and laser-generated plasmas. Detectors show high response velocity, low leakage current, high energy gap and high radiation hardness. Their high detection efficiency permits to use the detectors in spectroscopic mode and in time-of-flight (TOF) approach, generally employed to monitor low and high radiation fluxes, respectively. Using the laser start signal, they permit to study the properties of the generated plasma in vacuum by measuring accurately the particle velocity and energy using pulsed lasers at low and high intensities. Possible applications will be reported and discussed.

  14. POPULATION RADIATION PROTECTION PROVIDING UNDER THE INFLUENCE OF NATURAL IONIZING IRRADIATION SOURCES

    Directory of Open Access Journals (Sweden)

    E. G. Stepanov

    2015-01-01

    Full Text Available An article presents the modern problems of population radiation protection inBashkortostanRepublic. The main natural ionizing irradiation sources are identified and their contribution to the total exposure dose of the BashkortostanRepublicpopulation is analyzed. The types of the main natural ionizing irradiation sources are identified, as well as the ways of their intake and the methods of their influence. The results of laboratory studies are presented for the radon equivalent equilibrium volumetric activity, for the average gamma radiation dose rate in dwellings, for the investigations of gross alpha and gross beta activity in drinking water and open water sourcesBashkortostanRepublic. The article underlines the main problems of the radiation situation in the new construction. The main preventive measures are pointed out for the radiation protection of the buildings under construction improving. The article also presents an analysis of the results of activities of the Administration of Rospotrebnadzor in theBashkortostanRepublicfor the reducing of the levels of the Republican population exposure from the natural irradiation sources.

  15. Nanoscale displacement of the image of an atomic source of radiation

    Institute of Scientific and Technical Information of China (English)

    Xin Li; Jie Shu; Henk F. Arnoldus

    2009-01-01

    Light emitted by an atomic source of radiation appears to travel along a straight line (ray) from the location of the source to the observer in the far field. However, when the energy flow pattern of the radiation is resolved with an accuracy better than an optical wavelength, it turns out that the field lines are usually curved. We consider electric dipole radiation, a prime example of which is the radiation emitted by an atom during an electronic transition, and we show that the field lines of energy flow are in general curves. Near the location of the dipole, the field lines exhibit a vortex structure, and in the far field they approach a straight line. The spatial extension of the vortex in the optical near field is of nanoscale dimension. Due to the rotation of the field lines near the source, the asymptotic limit of a field line is not exactly in the radially outward direction and as a consequence, the image in the far field is slightly shifted. This sub-wavelength displacement of the image of the source should be amenable to experimental observation with contemporary nanoscale-precision techniques.

  16. Theoretical study on the carbon nanotube used ashard x—radiation source

    Institute of Scientific and Technical Information of China (English)

    LuJing-Han; QinXi-Jun

    1998-01-01

    Calculations and analyses are made on the interaction between the carbon nanotube and the incident positron of high energy.The results obtained show that it is possible to use carbon nanotube as hard X-radiation source with high intensity and good monochromaticity.

  17. Modelling the Impact of Ground Planes on Antenna Radiation Using the Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2007-01-01

    The Method of Auxiliary Sources is employed to model the impact of finite ground planes on the radiation from antennas. In many cases the computational cost of available commercial tools restricts the simulations to include only a small ground plane or, by use of the image principle, the infinitely...

  18. Axial dissipative dust as a source of gravitational radiation in f(R) gravity

    Science.gov (United States)

    Sharif, M.; Siddiqa, Aisha

    2017-03-01

    In this paper, we explore the source of gravitational radiation in the context of f(R) gravity by considering axially symmetric dissipative dust under geodesic condition. We evaluate scalars associated with electric and magnetic parts of the Weyl tensor for both non-spinning (at the center) and spinning (in the surrounding of the center) fluids of the configuration. For this purpose, we use the evolution as well as constraint equations for kinematical quantities and Weyl tensor. Finally, we investigate the existence of gravitational radiation through super-Poynting vector. It is found that the fluid is not gravitationally radiating in the non-spinning case but it is gravitationally radiating for the spinning case.

  19. Coherent Sources of XUV Radiation Soft X-Ray Lasers and High-Order Harmonic Generation

    CERN Document Server

    Jaeglé, Pierre

    2006-01-01

    Extreme ultraviolet radiation, also referred to as soft X-rays or XUV, offers very special optical properties. The X-UV refractive index of matter is such that normal reflection cannot take place on polished surfaces whereas beam transmission through one micrometer of almost all materials reduces to zero. Therefore, it has long been a difficult task to imagine and to implement devices designed for complex optics experiments in this wavelength range. Thanks to new sources of coherent radiation - XUV-lasers and High Order Harmonics - the use of XUV radiation, for interferometry, holography, diffractive optics, non-linear radiation-matter interaction, time-resolved study of fast and ultrafast phenomena and many other applications, including medical sciences, is ubiquitous.

  20. Design for an accelerator-based orthogonal epithermal neutron beam for boron neutron capture therapy.

    Science.gov (United States)

    Allen, D A; Beynon, T D; Green, S

    1999-01-01

    This paper is concerned with the proposed Birmingham accelerator-based epithermal neutron beam for boron neutron capture therapy (BNCT). In particular, the option of producing a therapy beam at an orthogonal direction to the incoming protons is considered. Monte Carlo radiation transport simulations, both with and without a head phantom, have shown that an orthogonal beam geometry is not only acceptable but is indeed beneficial, in terms of a lower mean neutron energy and an enhanced therapeutic ratio for the same useful neutron fluence in the therapy beam. Typical treatment times for various beam options have been calculated, and range from 20 to 48 min with a 5 mA beam of 2.8 MeV protons, if the maximum photon-equivalent dose delivered to healthy tissue is to be 12.6 Gy Eq. The effects of proton beam diameter upon the therapy beam parameters have also been considered.

  1. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  2. Management of ionizing radiation sources in university, medical and industrial environments; Gestion des sources ionisantes en milieux universitaire, medical et industriel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    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.)

  3. Beam conditions for radiation generated by an electromagnetic Hermite-Gaussian model source

    Institute of Scientific and Technical Information of China (English)

    LI Jia; XIN Yu; CHEN Yan-ru

    2011-01-01

    @@ Within the framework of the correlation theory of electromagnetic laser beams, the far field cross-spectral density matrix of the light radiated from an electromagnetic Hermite-Gaussian model source is derived.By utilizing the convergence property of Hermite polynomials, the conditions of the matrices for the source to generate an electromagnetic Hermite-Gaussian beam are obtained.Furthermore, in order to generate a scalar Hermite-Gaussian model beam, it is required that the source should be locally rather coherent in the spatial domain.

  4. Blind source separation of ship-radiated noise based on generalized Gaussian model

    Institute of Scientific and Technical Information of China (English)

    Kong Wei; Yang Bin

    2006-01-01

    When the distribution of the sources cannot be estimated accurately, the ICA algorithms failed to separate the mixtures blindly. The generalized Gaussian model (GGM) is presented in ICA algorithm since it can model nonGaussian statistical structure of different source signals easily. By inferring only one parameter, a wide class of statistical distributions can be characterized. By using maximum likelihood (ML) approach and natural gradient descent, the learning rules of blind source separation (BSS) based on GGM are presented. The experiment of the ship-radiated noise demonstrates that the GGM can model the distributions of the ship-radiated noise and sea noise efficiently, and the learning rules based on GGM gives more successful separation results after comparing it with several conventional methods such as high order cumulants and Gaussian mixture density function.

  5. Point-source idealization in classical field theories. II. Mechanical energy losses from electromagnetic radiation reaction

    Science.gov (United States)

    Kates, Ronald E.; Rosenblum, Arnold

    1982-05-01

    This paper compares the mechanical energy losses due to electromagnetic radiation reaction on a two-particle, slow-motion system, as calculated from (1) the method of matched asymptotic expansions and (2) the Lorentz-Dirac equation, which assumes point sources. The matching derivation of the preceding paper avoided the assumption of a δ-function source by using Reissner-Nordström matching zones. Despite the differing mathematical assumptions of the two methods, their results are in agreement with each other and with the electromagnetic-field energy losses calculated by the evaluation of flux integrals. Our purpose is eventually to analyze Rosenblum's use of point sources as a possible cause of disagreement between the analogous calculations of gravitational radiation on a slow-motion system of two bodies. We begin with the simpler electromagnetic problem.

  6. 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

    2008-08-01

    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 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 resolution model

  7. Direct structuring of solids by EUV radiation from a table-top laser produced plasma source

    Science.gov (United States)

    Barkusky, Frank; Bayer, Armin; Peth, Christian; Mann, Klaus

    2009-05-01

    In recent years, technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. Currently, the application of EUV radiation apart from microlithography comes more and more into focus. Main goal of our research is to utilize the unique interaction between soft x-ray radiation and matter for probing, modifying, and structuring solid surfaces. In this contribution we present a setup capable of generating and focusing EUV radiation. It consists of a table-top laser-produced plasma source. In order to obtain a small focal spot resulting in high EUV fluence, a modified Schwarzschild objective consisting of two spherical mirrors with Mo/Si multilayer coatings is adapted to this source, simultaneously blocking unwanted out-of-band radiation. By demagnified (10x) imaging of the plasma an EUV spot of 5 μm diameter with a maximum energy density of ~0.72 J/cm² is generated (pulse length 8.8 ns). We present first applications of this integrated source and optics system, demonstrating its potential for high-resolution modification and structuring of solid surfaces. As an example, etch rates for PMMA, PC and PTFE depending on EUV fluences were determined, indicating a linear etch behavior for lower energy densities. In order to investigate changes of the chemical composition of PMMA induced by EUV radiation we present FTIR and NEXAFS measurements on irradiated samples. The latter were performed using the laboratory source tuned to the XUV spectral range around the carbon K-edge (λ ~ 4.4 nm) and a flat-field spectrometer. For showing the potential of this setup, first damage tests were performed on grazing incidence gold mirrors. For these thin Gold films, threshold energy densities could be determined, scaling linear with the film thickness.

  8. Bernoulli particle filter with observer altitude for maritime radiation source tracking in the presence of measurement uncertainty

    Institute of Scientific and Technical Information of China (English)

    Luo Xiaobo; Fan Hongqi; Song Zhiyong; Fu Qiang

    2013-01-01

    For maritime radiation source target tracking in particular electronic counter measures (ECM) environment, there exists two main problems which can deteriorate the tracking perfor-mance of traditional approaches. The first problem is the poor observability of the radiation source. The second one is the measurement uncertainty which includes the uncertainty of the target appear-ing/disappearing and the detection uncertainty (false and missed detections). A novel approach is proposed in this paper for tracking maritime radiation source in the presence of measurement uncertainty. To solve the poor observability of maritime radiation source target, using the radiation source motion restriction, the observer altitude information is incorporated into the bearings-only tracking (BOT) method to obtain the unique target localization. Then the two uncertainties in the ECM environment are modeled by the random finite set (RFS) theory and the Bernoulli filtering method with the observer altitude is adopted to solve the tracking problem of maritime radiation source in such context. Simulation experiments verify the validity of the proposed approach for tracking maritime radiation source, and also demonstrate the superiority of the method compared with the traditional integrated probabilistic data association (IPDA) method. The tracking perfor-mance under different conditions, particularly those involving different duration of radiation source opening and switching-off, indicates that the method to solve our problem is robust and effective.

  9. Intensity and polarization of radiation emerging from a semi-infinite medium containing assigned sources

    Science.gov (United States)

    Silantev, N. A.

    1980-06-01

    Exact values are given for the intensity and linear polarization of radiation emerging from a semiinfinite medium which consists of small, absorbing, isotropically polarizing particles. The following cases are considered: the sources of unpolarized radiation are distributed in the medium uniformly, grow linearly or quadratically into the interior of the medium, decline exponentially away from the boundary, or are located at an infinitely large distance from the boundary of the medium (the Milne problem). The depolarizing influence of the possible anisotropy of the scattering particles is also estimated.

  10. Definition of loss-of-coolant accident radiation source. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Definition of loss-of-coolant accident radiation source: summary and conclusions. [BWR; PWR

    Energy Technology Data Exchange (ETDEWEB)

    Bonzon, L.L.; Lurie, N.A.; Houston, D.H.; Naber, J.A.

    1978-05-01

    The radiation energy release rates and spectra corresponding to those sources specified in USNRC Regulatory Guide 1.89 for the radiation qualification of Class 1E equipment were calculated. The effects of several parameters (some not specific in the Guide), such as reactor fuel composition, operating duration and power level, and treatment of progeny, are evaluated. The results are presented as time-dependent beta and gamma-ray energy release rates and spectra which are fundamental quantities that are not specific to a plant design but are generally applicable to any nuclear power station.

  12. A critical experimental test of synchrotron radiation theory with 3rd generation light source

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-05-15

    A recent ''beam splitting'' experiment at LCLS apparently demonstrated that after a microbunched electron beam is kicked on a large angle compared to the divergence of the FEL radiation, the microbunching wave front is readjusted along the new direction of motion of the kicked beam. Therefore, coherent radiation from an undulator placed after the kicker is emitted along the kicked direction without suppression. This strong emission of coherent undulator radiation in the kicked direction cannot be explained in the framework of conventional synchrotron radiation theory. In a previous paper we explained this puzzle. We demonstrated that, in accelerator physics, the coupling of fields and particles is based, on the one hand, on the use of results from particle dynamics treated according to the absolute time convention and, on the other hand, on the use of Maxwell equations treated according to the standard (Einstein) synchronization convention. Here lies the misconception which led to the strong qualitative disagreement between theory and experiment. After the ''beam splitting'' experiment at LCLS, it became clear that the conventional theory of synchrotron radiation cannot ensure the correct description of coherent and spontaneous emission from a kicked electron beam, nor the emission from a beam with finite angular divergence, in an undulator or a bending magnet. However, this result requires further experimental confirmation. In this publication we propose an uncomplicated and inexpensive experiment to test synchrotron radiation theory at 3rd generation light sources.

  13. Applications of Accelerators and Radiation Sources in the Field of Space Research and Industry.

    Science.gov (United States)

    Campajola, Luigi; Di Capua, Francesco

    2016-12-01

    Beyond their important economic role in commercial communications, satellites in general are critical infrastructure because of the services they provide. In addition to satellites providing information which facilitates a better understanding of the space environment and improved performance of physics experiments, satellite observations are also used to actively monitor weather, geological processes, agricultural development and the evolution of natural and man-made hazards. Defence agencies depend on satellite services for communication in remote locations, as well as for reconnaissance and intelligence. Both commercial and government users rely on communication satellites to provide communication in the event of a disaster that damages ground-based communication systems, provide news, education and entertainment to remote areas and connect global businesses. The space radiation environment is an hazard to most satellite missions and can lead to extremely difficult operating conditions for all of the equipment travelling in space. Here, we first provide an overview of the main components of space radiation environment, followed by a description of the basic mechanism of the interaction of radiation with matter. This is followed by an introduction to the space radiation hardness assurance problem and the main effects of natural radiation to the microelectronics (total ionizing dose, displacement damage and the single-event effect and a description of how different effects occurring in the space can be tested in on-ground experiments by using particle accelerators and radiation sources. We also discuss standards and the recommended procedures to obtain reliable results.

  14. Saturn Neutron Exosphere as Source for Inner and Innermost Radiation Belts

    Science.gov (United States)

    Cooper, John; Lipatov, Alexander; Sittler, Edward; Sturner, Steven

    2011-01-01

    Energetic proton and electron measurements by the ongoing Cassini orbiter mission are expanding our knowledge of the highest energy components of the Saturn magnetosphere in the inner radiation belt region after the initial discoveries of these belts by the Pioneer 11 and Voyager 2 missions. Saturn has a neutron exosphere that extends throughout the magnetosphere from the cosmic ray albedo neutron source at the planetary main rings and atmosphere. The neutrons emitted from these sources at energies respectively above 4 and 8 eV escape the Saturn system, while those at lower energies are gravitationally bound. The neutrons undergo beta decay in average times of about 1000 seconds to provide distributed sources of protons and electrons throughout Saturn's magnetosphere with highest injection rates close to the Saturn and ring sources. The competing radiation belt source for energetic electrons is rapid inward diffusion and acceleration of electrons from the middle magnetosphere and beyond. Minimal losses during diffusive transport across the moon orbits, e.g. of Mimas and Enceladus, and local time asymmetries in electron intensity, suggest that drift resonance effects preferentially boost the diffusion rates of electrons from both sources. Energy dependences of longitudinal gradient-curvature drift speeds relative to the icy moons are likely responsible for hemispheric differences (e.g., Mimas, Tethys) in composition and thermal properties as at least partly produced by radiolytic processes. A continuing mystery is the similar radial profiles of lower energy (belt region. Either the source of these lower energy protons is also neutron decay, but perhaps alternatively from atmospheric albedo, or else all protons from diverse distributed sources are similarly affected by losses at the moon' orbits, e.g. because the proton diffusion rates are extremely low. Enceladus cryovolcanism, and radiolytic processing elsewhere on the icy moon and ring surfaces, are additional

  15. Development of sup 1 sup 9 sup 2 Ir radiation sources for intravascular irradiation

    CERN Document Server

    Kogure, H; Iwamoto, S; Iwata, K; Kawauchi, Y; Nagata, Y; Sorita, T; Suzuki, K

    2003-01-01

    Intravascular brachytherapy is a novel therapy for preventing the restenosis of coronary artery by use of low-dose irradiation. JAERI and Kyoto University have been developing sup 1 sup 9 sup 2 Ir radiation sources by the cooperative research project entitled as 'The research on safety and effectiveness of the intravascular brachytherapy for preventing restenosis of the coronary artery disease' since 1998. The radiation source was introduced into the stenosis through a catheter (a guide-tube to insert directly into vascular) to irradiate the diseased part. Ten sup 1 sup 9 sup 2 Ir seed sources (phi 0.4 mm x 2.5 mm) were positioned between nylon spacers (phi 0.3 mm x 1.0 mm) in a flexible covering tube and the tube was plugged with a core-wire; the tube was shrunk to fix the inside materials and the size is 0.46 mm in diameter and 3 m in length. The physically optimal design was determined to insert the radiation source easily into vascular and to get the dose uniformity in the diseased part. The production me...

  16. Nonuniformity correction of infrared cameras by reading radiance temperatures with a spatially nonhomogeneous radiation source

    Science.gov (United States)

    Gutschwager, Berndt; Hollandt, Jörg

    2017-01-01

    We present a novel method of nonuniformity correction (NUC) of infrared cameras and focal plane arrays (FPA) in a wide optical spectral range by reading radiance temperatures and by applying a radiation source with an unknown and spatially nonhomogeneous radiance temperature distribution. The benefit of this novel method is that it works with the display and the calculation of radiance temperatures, it can be applied to radiation sources of arbitrary spatial radiance temperature distribution, and it only requires sufficient temporal stability of this distribution during the measurement process. In contrast to this method, an initially presented method described the calculation of NUC correction with the reading of monitored radiance values. Both methods are based on the recording of several (at least three) images of a radiation source and a purposeful row- and line-shift of these sequent images in relation to the first primary image. The mathematical procedure is explained in detail. Its numerical verification with a source of a predefined nonhomogeneous radiance temperature distribution and a thermal imager of a predefined nonuniform FPA responsivity is presented.

  17. New Advanced Source Identification Algorithm (ASIA-NEW) for radiation monitors with plastic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Stavrov, Andrei; Yamamoto, Eugene [Rapiscan Systems, Inc., 14000 Mead Street, Longmont, CO, 80504 (United States)

    2015-07-01

    Radiation Portal Monitors (RPM) with plastic detectors represent the main instruments used for primary border (customs) radiation control. RPM are widely used because they are simple, reliable, relatively inexpensive and have a high sensitivity. However, experience using the RPM in various countries has revealed the systems have some grave shortcomings. There is a dramatic decrease of the probability of detection of radioactive sources under high suppression of the natural gamma background (radiation control of heavy cargoes, containers and, especially, trains). NORM (Naturally Occurring Radioactive Material) existing in objects under control trigger the so-called 'nuisance alarms', requiring a secondary inspection for source verification. At a number of sites, the rate of such alarms is so high it significantly complicates the work of customs and border officers. This paper presents a brief description of new variant of algorithm ASIA-New (New Advanced Source Identification Algorithm), which was developed by the authors and based on some experimental test results. It also demonstrates results of different tests and the capability of a new system to overcome the shortcomings stated above. New electronics and ASIA-New enables RPM to detect radioactive sources under a high background suppression (tested at 15-30%) and to verify the detected NORM (KCl) and the artificial isotopes (Co-57, Ba-133 and other). New variant of ASIA is based on physical principles and does not require a lot of special tests to attain statistical data for its parameters. That is why this system can be easily installed into any RPM with plastic detectors. This algorithm was tested for 1,395 passages of different transports (cars, trucks and trailers) without radioactive sources. It also was tested for 4,015 passages of these transports with radioactive sources of different activity (Co-57, Ba-133, Cs-137, Co-60, Ra-226, Th-232) and these sources masked by NORM (K-40) as well

  18. Transverse coherence properties of X-ray beams in third-generation synchrotron radiation sources

    CERN Document Server

    Geloni, Gianluca; Schneidmiller, Evgeni; Yurkov, Mikhail

    2008-01-01

    This article describes a complete theory of spatial coherence for undulator radiation sources. Current estimations of coherence properties often assume that undulator sources are quasi-homogeneous, like thermal sources, and rely on the application of the van Cittert-Zernike theorem for calculating the degree of transverse coherence. Such assumption is not adequate when treating third generation light sources, because the vertical(geometrical) emittance of the electron beam is comparable or even much smaller than the radiation wavelength in a very wide spectral interval that spans over four orders of magnitude (from 0.1 Angstrom up to 10^3 Angstrom). Sometimes, the so-called Gaussian-Schell model, that is widely used in statistical optics in the description of partially-coherent sources, is applied as an alternative to the quasi-homogeneous model. However, as we will demonstrate, this model fails to properly describe coherent properties of X-ray beams from non-homogeneous undulator sources. As a result, a more...

  19. Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries

    Directory of Open Access Journals (Sweden)

    Blanchet Luc

    2002-01-01

    Full Text Available The article reviews the current status of a theoretical approach to the problem of the emission of gravitational waves by isolated systems in the context of general relativity. Part aaa of the article deals with general post-Newtonian sources. The exterior field of the source is investigated by means of a combination of analytic post-Minkowskian and multipolar approximations. The physical observables in the far-zone of the source are described by a specific set of radiative multipole moments. By matching the exterior solution to the metric of the post-Newtonian source in the near-zone we obtain the explicit expressions of the source multipole moments. The relationships between the radiative and source moments involve many non-linear multipole interactions, among them those associated with the tails (and tails-of-tails of gravitational waves. Part bbb of the article is devoted to the application to compact binary systems. We present the equations of binary motion, and the associated Lagrangian and Hamiltonian, at the third post-Newtonian (3PN order beyond the Newtonian acceleration. The gravitational-wave energy flux, taking consistently into account the relativistic corrections in the binary moments as well as the various tail effects, is derived through 3.5PN order with respect to the quadrupole formalism. The binary's orbital phase, whose prior knowledge is crucial for searching and analyzing the signals from inspiralling compact binaries, is deduced from an energy balance argument.

  20. Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries

    Directory of Open Access Journals (Sweden)

    Blanchet Luc

    2006-06-01

    Full Text Available The article reviews the current status of a theoretical approach to the problem of the emission of gravitational waves by isolated systems in the context of general relativity. Part A of the article deals with general post-Newtonian sources. The exterior field of the source is investigated by means of a combination of analytic post-Minkowskian and multipolar approximations. The physical observables in the far-zone of the source are described by a specific set of radiative multipole moments. By matching the exterior solution to the metric of the post-Newtonian source in the near-zone we obtain the explicit expressions of the source multipole moments. The relationships between the radiative and source moments involve many non-linear multipole interactions, among them those associated with the tails (and tails-of-tails of gravitational waves. Part B of the article is devoted to the application to compact binary systems. We present the equations of binary motion, and the associated Lagrangian and Hamiltonian, at the third post-Newtonian (3PN order beyond the Newtonian acceleration. The gravitational-wave energy flux, taking consistently into account the relativistic corrections in the binary moments as well as the various tail effects, is derived through 3.5PN order with respect to the quadrupole formalism. The binary's orbital phase, whose prior knowledge is crucial for searching and analyzing the signals from inspiralling compact binaries, is deduced from an energy balance argument.

  1. Radiation Tolerance Qualification Tests of the Final Source Interface Unit for the ALICE Experiment

    CERN Document Server

    Dénes, E; Futó, E; Kerék, A; Kiss, T; Molnár, J; Novák, D; Soós, C; Tölyhi, T; Van de Vyvre, P

    2007-01-01

    The ALICE Detector Data Link (DDL) is a high-speed optical link designed to interface the readout electronics of ALICE sub-detectors to the DAQ computers. The Source Interface Unit (SIU) of the DDL will operate in radiation environment. Previous tests showed that a configuration loss of SRAM-based FPGA devices may happen and the frequency of undetected data errors in the FPGA user memory area is also not acceptable. Therefore, we redesigned the SIU card using another FPGA based on flash technology. In order to detect bit errors in the user memory we added parity check logic to the design. The new SIU has been extensively tested using neutron and proton irradiation to verify its radiation tolerance. In this paper we summarize the design changes, introduce the final design, and the results of the radiation tolerance measurements on the final card.

  2. Advisory Committee on human radiation experiments. Supplemental Volume 2a, Sources and documentation appendices. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    This large document provides a catalog of the location of large numbers of reports pertaining to the charge of the Presidential Advisory Committee on Human Radiation Research and is arranged as a series of appendices. Titles of the appendices are Appendix A- Records at the Washington National Records Center Reviewed in Whole or Part by DoD Personnel or Advisory Committee Staff; Appendix B- Brief Descriptions of Records Accessions in the Advisory Committee on Human Radiation Experiments (ACHRE) Research Document Collection; Appendix C- Bibliography of Secondary Sources Used by ACHRE; Appendix D- Brief Descriptions of Human Radiation Experiments Identified by ACHRE, and Indexes; Appendix E- Documents Cited in the ACHRE Final Report and other Separately Described Materials from the ACHRE Document Collection; Appendix F- Schedule of Advisory Committee Meetings and Meeting Documentation; and Appendix G- Technology Note.

  3. Organic Materials Ionizing Radiation Susceptibility for the Outer Planet/Solar Probe Radioisotope Power Source

    Science.gov (United States)

    Golliher, Eric L.; Pepper, Stephen V.

    2001-01-01

    The Department of Energy is considering the current Stirling Technology Corporation 55 We Stirling Technology Demonstration Convertor as a baseline option for an advanced radioisotope power source for the Outer Planets/Solar Probe project of Jet Propulsion Laboratory and other missions. However, since the Technology Demonstration Convertor contains organic materials chosen without any special consideration of flight readiness, and without any consideration of the extremely high radiation environment of Europa, a preliminary investigation was performed to address the radiation susceptibility of the current organic materials used in the Technology Demonstration Convertor. This report documents the results of the investigation. The results of the investigation show that candidate replacement materials have been identified to be acceptable in the harsh Europa radiation environment.

  4. Radiation exposure modeling for apartment living spaces with multiple radioactive sources.

    Science.gov (United States)

    Hwang, J S; Chan, C C; Wang, J D; Chang, W P

    1998-03-01

    Since late 1992, over 100 building complexes in Taiwan, including both public and private schools, and 1,000 apartments have been identified as emitting elevated levels of gamma-radiation. These high levels of gamma-radiation have been traced to construction steel contaminated with 60Co. Accurate reconstruction of the radiation exposure dosage among residents is complicated by the discovery of multiple radioactive sources within the living spaces and by the lack of comprehensive information about resident life-style and occupancy patterns within these contaminated spaces. The objective of this study was to evaluate the sensitivity of current dose reconstruction approach employed in an epidemiological study for the health effects of these occupants. We apply a statistical method of local smoothing in dose rate estimation and examine factors that are closely associated with radiation exposure from multiple radioactive sources in the apartment. Two examples are used, a simulated measurement in a hypothetical room with three radioactive sources and a real apartment in Ming-Shan Villa, one of the contaminated buildings. The simulated and estimated means are compared along 5-10 selected points of measurement: by local smoothing approach, with the furniture-adjusted space, and with the occupancy time-weighted mean. We found that the local smoothing approach came much closer to theoretical values. The local smoothing approach may serve as a refined method of radiation dose distribution modeling in exposure estimation. Before environmental exposure assessment, "highly occupied zones" (HOZs) in the contaminated spaces must be identified. Estimates of the time spent in these HOZs are essential to obtain accurate dosage values. These results will facilitate a more accurate dose reconstruction in the assessment of residential exposure in apartments with elevated levels of radioactivity.

  5. Passive Lossless Huygens Metasurfaces for Conversion of Arbitrary Source Field to Directive Radiation

    CERN Document Server

    Epstein, Ariel

    2014-01-01

    We present a semi-analytical formulation of the interaction between a given source field and a scalar Huygens metasurface (HMS), a recently introduced promising concept for wavefront manipulation based on a sheet of orthogonal electric and magnetic dipoles. Utilizing the equivalent surface impedance representation of these metasurfaces, we establish that an arbitrary source field can be converted into directive radiation via a passive lossless HMS if two physical conditions are met: local power conservation and local impedance equalization. Expressing the fields via their plane-wave spectrum and harnessing the slowly-varying envelope approximation we obtain semi-analytical formulae for the scattered fields, and prescribe the surface reactance required for the metasurface implementation. The resultant design procedure indicates that the local impedance equalization induces a Fresnel-like reflection, while local power conservation forms a radiating virtual aperture which follows the total excitation field magni...

  6. Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries

    CERN Document Server

    Blanchet, Luc

    2013-01-01

    To be observed and analyzed by the network of gravitational wave detectors on ground (LIGO, VIRGO, etc.) and by the future detectors in space (LISA, etc.), inspiralling compact binaries --- binary star systems composed of neutron stars and/or black holes in their late stage of evolution --- require high-accuracy templates predicted by general relativity theory. The gravitational waves emitted by these very relativistic systems can be accurately modelled using a high-order post-Newtonian gravitational wave generation formalism. In this article, we present the current state of the art on post-Newtonian methods as applied to the dynamics and gravitational radiation of general matter sources (including the radiation reaction back onto the source) and inspiralling compact binaries. We describe the post-Newtonian equations of motion, pay attention to the self-field regularizations at work, discuss several notions of innermost circular orbits, estimate the accuracy of the approximation and make a comparison with num...

  7. Tunable THz radiation source from dielectric loaded waveguide excited by nonrelativistic electron bunch trains

    Science.gov (United States)

    Li, Weiwei; He, Zhigang; Lu, Yalin; Huang, Ruixuan; Liu, Weihao; Jia, Qika; Wang, Lin

    2016-10-01

    We propose a novel scheme to generate a tunable narrow-band THz radiation. In this scheme, a train of laser pulses with THz repetition rate is used to drive a photocathode direct current (DC) gun, leading to the emission of a train of electron bunches. The electron bunch train is subsequently accelerated by the gun field and applied to selectively excite one of the modes in the dielectric loaded waveguide (DLW) structure, which is located downstream the DC gun. Thanks to the tunability of the repetition rate of laser pulses and the gun voltage, a tunable narrow-band THz radiation source can be obtained. This proposed source has the advantages of compactness, robustness and relatively high power.

  8. Impact of next-generation synchrotron radiation sources on materials research

    CERN Document Server

    Shenoy, G K

    2003-01-01

    Three generations of synchrotron radiation sources have revolutionized our understanding of various correlations in the equilibrium phase of materials through X-ray imaging, spectroscopy and scattering techniques. It is anticipated that new sources based on energy-recovery linacs and X-ray free-electron lasers will deliver X-ray pulses that are below a few-hundred femtoseconds in length and have very high coherence. These sources will extend and broaden our current knowledge of materials science. But more importantly, it is expected that these sources will provide the first glimpse of nonequilibrium processes in materials, including nonthermal melting, metal-insulator transitions involving nonequilibrium phases, laser-induced catalytic oxidation, and determining the structure of imperfect nanoparticles lacking crystalline structure.

  9. Non ionizing radiations Sources, fields of application, problem issues and normatives

    CERN Document Server

    Raganella, L

    1988-01-01

    The purpose of this paper is briefly to review radiation sources, in work and life places, and national standards, proposed or enforced in different countries, with particular reference to ELF. RF and MW electromagnetic fields. It is aimed to give a help to qualitative valutation on the work we can carry out for the development of an effective health protection of workers and general public.

  10. Correlation of radiation dose and heart rate in dual-source computed tomography coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Laspas, Fotios; Roussakis, Arkadios; Kritikos, Nikolaos; Efthimiadou, Roxani; Kehagias, Dimitrios; Andreou, John (CT and MRI Dept., Hygeia Hospital, Athens (Greece)), e-mail: fotisdimi@yahoo.gr; Tsantioti, Dimitra (Statistician, Hygeia Hospital, Athens (Greece))

    2011-04-15

    Background: Computed tomography coronary angiography (CTCA) has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but the relatively high radiation dose remains a major concern. Purpose: To evaluate the relationship between radiation exposure and heart rate (HR), in dual-source CTCA. Material and Methods: Data from 218 CTCA examinations, performed with a dual-source 64-slices scanner, were statistically evaluated. Effective radiation dose, expressed in mSv, was calculated as the product of the dose-length product (DLP) times a conversion coefficient for the chest (mSv = DLPx0.017). Heart rate range and mean heart rate, expressed in beats per minute (bpm) of each individual during CTCA, were also provided by the system. Statistical analysis of effective dose and heart rate data was performed by using Pearson correlation coefficient and two-sample t-test. Results: Mean HR and effective dose were found to have a borderline positive relationship. Individuals with a mean HR >65 bpm observed to receive a statistically significant higher effective dose as compared to those with a mean HR =65 bpm. Moreover, a strong correlation between effective dose and variability of HR of more than 20 bpm was observed. Conclusion: Dual-source CT scanners are considered to have the capability to provide diagnostic examinations even with high HR and arrhythmias. However, it is desirable to keep the mean heart rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure

  11. Physical infeasibility of geodesic dissipative dust as a source of gravitational radiation

    CERN Document Server

    Herrera, L; Ospino, J

    2015-01-01

    Using a framework based on the 1+3 formalism, we show that a source represented by a geodesic, dissipative, rotational dust, endowed with axial and reflection symmetry, violates regularity conditions at the center of the fluid distribution, unless the dissipative flux vanishes. In this latter case the vorticity also must vanish, and the resulting spacetime is Friedman--Robertson--Walker (FRW). Therefore it does not produce gravitational radiation.

  12. Limitation of the Polarization by Radiation Trapping in a Helium Afterglow Electron Source

    Science.gov (United States)

    Brissaud, I.; Jacquemin, C.

    1995-01-01

    A polarized electron source using an optically pumped helium afterglow was built at Orsay. Unfortunately the spin polarization decreases at high metastable densities. Calculations of the radiation trapping effects in a weak magnetic field are presented using the Anderson formalism. Comparison with experimental data leads to the conclusion that these trapping effects are one explanation of this polarization decrease. Effects of the main parameters are studied. Some deductions for a new design can be made.

  13. Optimization of industrial processes using radiation sources; Otimizacao dos trabalhos envolvendo radiacao industrial

    Energy Technology Data Exchange (ETDEWEB)

    Salles, Claudio G.; Silva Filho, Edmundo D. da; Toribio, Norberto M.; Gandara, Leonardo A. [SAMARCO Mineracao S.A., Mariana, MG (Brazil). Mina de Germano

    1996-12-31

    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 8 figs., 1 tab.

  14. Low Temperature Epitaxial Growth of Semiconductors Using Synchrotron Radiation as a Light Source

    Institute of Scientific and Technical Information of China (English)

    Qixin GUO; Mitsuhiro NISHIO; Hiroshi OGAWA

    2000-01-01

    Results of our recent experiments relating to the synchrotron radiation (SR) excited growth of Ⅱ-V compounds using metalorganic sources are described. We discuss mainly the growth characteristics of films in addition to the characterization of the deposited films. ZnTe epitaxial layer without carbon and oxygen contamination is attainable even at room temperature using SR as a light source. The quantum yield for forming ZnTe molecules was estimated to be higher than 3%. Through these experiments, we propose that the SR-excited growth is a powerful technique for a novel low temperature growth of compounds.

  15. Multi-pass Accelerator-Recuperator (MARS) as Coherent X-ray Synchrotron Radiation Source

    Science.gov (United States)

    Kulipanov, Gennady; Skrinsky, Alexander; Vinokurov, Nikolai

    2007-01-01

    Creation of a fully spatial coherent 4th generation SR source is possible in case of a shift from the electron storage rings to accelerators with energy recovery. However, in practice, all the projects assume the use of a single-turn version (ERL) compared to our first proposal of 1997 to use a multi-turn accelerator-recuperator (MARS). The purpose of this report is presentation of the modern conception of MARS and comparison of the ERL and MARS based radiation sources from the viewpoint of their realization in practice.

  16. Compact Z-pinch radiation source dedicated to broadband absorption measurements

    Directory of Open Access Journals (Sweden)

    Dunpin Hong

    2016-05-01

    Full Text Available In order to acquire a broadband absorption spectrum in a single shot, a compact radiation source was developed by using a Z-pinch type electric discharge. This paper presents the mechanical and electrical construction of the source, as well as its electrical and optical characteristics, including the intense continuum of radiation emitted by the source in the UV and visible spectral range. It also shows that the compactness of the source allows direct coupling with the probed medium, enabling broadband absorption measurement in the spectral range of 200–300 nm without use of an optical fiber which strongly attenuates the light in the short wavelength range. Concretely, thanks to this source, broadband spectral absorption of NO molecules around 210 nm and that of OH molecules around 310 nm were recorded in this direct coupling arrangement. Copper atom spectral absorption around 325 nm of the peripheral cold zones of an intense transient arc was also recorded.

  17. Ionizing radiations management in university, medical and industrial media; La gestion des sources ionisantes en milieux universitaire, medical et industriel

    Energy Technology Data Exchange (ETDEWEB)

    Klein, D. [Universite Technologique de Belfort Montbeliard - LERMPS, 90 - Belfort (France)]|[Universite de Franche Comte, CREST-IRMA, 25 - Montbeliard (France)

    2001-07-01

    The radioactive sources are useful in several areas: medicine, research, measurement laboratories. Severe accidents in the past (Forbach in France 1991, Arequipa, Peru 1999, Goiania, Brazil 1987) remind us of the dangerous character of ionizing radiations. That is why the the management of radioactive sources are so regulated. Radiation protection and legal aspects of sealed and unsealed sources management are evoked, as well as the different official organisms that take a part in their management. (N.C.)

  18. Quantitative elemental analysis of an industrial mineral talc, using accelerator-based analytical technique

    Energy Technology Data Exchange (ETDEWEB)

    Olabanji, S.O. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Legnaro, viale dell' Universita 2, 35020 Legnaro (Padova) (Italy) and Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife (Nigeria)]. E-mail: skayode2002@yahoo.co.uk; Ige, A.O. [Natural History Museum, Obafemi Awolowo University, Ile-Ife (Nigeria); Mazzoli, C. [Dipartimento di Mineralogia e Petrologia, Universita di Padova, 35100 Padova (Italy); Ceccato, D. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Legnaro, viale dell' Universita 2, 35020 Legnaro (Padova) (Italy); Dipartimento di Fisica, Universita di Padova, via Marzolo 8, 35100 Padova (Italy); Ajayi, E.O.B. [Department of Physics, Obafemi Awolowo University, Ile-Ife (Nigeria); De Poli, M. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Legnaro, viale dell' Universita 2, 35020 Legnaro (Padova) (Italy); Moschini, G. [Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Legnaro, viale dell' Universita 2, 35020 Legnaro (Padova) (Italy); Dipartimento di Fisica, Universita di Padova, via Marzolo 8, 35100 Padova (Italy)

    2005-10-15

    Accelerator-based technique of PIXE was employed for the determination of the elemental concentration of an industrial mineral, talc. Talc is a very versatile mineral in industries with several applications. Due to this, there is a need to know its constituents to ensure that the workers are not exposed to health risks. Besides, microscopic tests on some talc samples in Nigeria confirm that they fall within the BP British Pharmacopoeia standard for tablet formation. However, for these samples to become a local source of raw material for pharmaceutical grade talc, the precise elemental compositions should be established which is the focus of this work. Proton beam produced by the 2.5 MV AN 2000 Van de Graaff accelerator at INFN, LNL, Legnaro, Padova, Italy was used for the PIXE measurements. The results which show the concentration of different elements in the talc samples, their health implications and metabolic roles are presented and discussed.

  19. Superradiant THz undulator radiation source based on a superconducting photo-injector

    Science.gov (United States)

    Wen, Xiaodong; Huang, Senlin; Lin, Lin; Wang, Fang; Zhu, Feng; Feng, Liwen; Yang, Limin; Wang, Zhiwen; Fan, Peiliang; Hao, Jiankui; Quan, Shengwen; Liu, Kexin; Chen, Jia-er

    2016-06-01

    Superconducting radio frequency accelerators are used to produce terahertz (THz) radiation pulses with a high repetition rate. In this study, a compact high repetition rate THz radiation source has been developed based on a DC-SRF photo-injector through velocity bunching at Peking University. This compact THz source can theoretically generate approximately 1 W of superradiant THz radiation, with a repetition rate of 16.25 MHz and a frequency that can be tuned from 0.24 THz to 0.42 THz by varying the electron beam energy from 2.4 MeV to 3.1 MeV. Simulation results indicate that the asymmetrical longitudinal distribution of electrons in each bunch caused by velocity bunching increases the THz power by about 2 orders at wavelength within 400-700 μm. Experimental measurements are consistent with the calculation results when propagation loss is considered. This paper presents the system description, simulation, and experiments of the high repetition rate THz source.

  20. Investigating the source of near-relativistic and relativistic electrons in Earth's inner radiation belt

    Science.gov (United States)

    Turner, D. L.; O'Brien, T. P.; Fennell, J. F.; Claudepierre, S. G.; Blake, J. B.; Jaynes, A. N.; Baker, D. N.; Kanekal, S.; Gkioulidou, M.; Henderson, M. G.; Reeves, G. D.

    2017-01-01

    Using observations from NASA's Van Allen Probes, we study the role of sudden particle enhancements at low L shells (SPELLS) as a source of inner radiation belt electrons. SPELLS events are characterized by electron intensity enhancements of approximately an order of magnitude or more in less than 1 day at L belt electrons under quiet/average conditions. During SPELLS events, the evolution of electron distributions reveals an enhancement of phase space density that can exceed 3 orders of magnitude in the slot region and continues into the inner radiation belt, which is evidence that these events are an important - and potentially dominant - source of inner belt electrons. Electron fluxes from September 2012 through February 2016 reveal that SPELLS occur frequently ( 2.5/month at 200 keV), but the number of observed events decreases exponentially with increasing electron energy for ≥100 keV. After SPELLS events, the slot region reforms due to slow energy-dependent decay over several day time scales, consistent with losses due to interactions with plasmaspheric hiss. Combined, these results indicate that the peaked phase space density distributions in the inner electron radiation belt result from an "on/off," geomagnetic-activity-dependent source from higher radial distances.

  1. Phylogenomics Reveals Three Sources of Adaptive Variation during a Rapid Radiation.

    Directory of Open Access Journals (Sweden)

    James B Pease

    2016-02-01

    Full Text Available Speciation events often occur in rapid bursts of diversification, but the ecological and genetic factors that promote these radiations are still much debated. Using whole transcriptomes from all 13 species in the ecologically and reproductively diverse wild tomato clade (Solanum sect. Lycopersicon, we infer the species phylogeny and patterns of genetic diversity in this group. Despite widespread phylogenetic discordance due to the sorting of ancestral variation, we date the origin of this radiation to approximately 2.5 million years ago and find evidence for at least three sources of adaptive genetic variation that fuel diversification. First, we detect introgression both historically between early-branching lineages and recently between individual populations, at specific loci whose functions indicate likely adaptive benefits. Second, we find evidence of lineage-specific de novo evolution for many genes, including loci involved in the production of red fruit color. Finally, using a "PhyloGWAS" approach, we detect environment-specific sorting of ancestral variation among populations that come from different species but share common environmental conditions. Estimated across the whole clade, small but substantial and approximately equal fractions of the euchromatic portion of the genome are inferred to contribute to each of these three sources of adaptive genetic variation. These results indicate that multiple genetic sources can promote rapid diversification and speciation in response to new ecological opportunity, in agreement with our emerging phylogenomic understanding of the complexity of both ancient and recent species radiations.

  2. Analysis of stray radiation produced by the advanced light source (1.9 GeV synchrotron radiation source) at Lawrence Berkeley Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Ajemian, Robert C. [Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Environmental Sciences and Engineering

    1995-01-01

    The yearly environmental dose equivalent likely to result at the closest site boundary from the Advanced Light Source was determined by generating multiple linear regressions. The independent variables comprised quantified accelerator operating parameters and measurements from synchronized, in-close (outside shielding prior to significant atmospheric scattering), state-of-the-art neutron remmeters and photon G-M tubes. Neutron regression models were more successful than photon models due to lower relative background radiation and redundant detectors at the site boundary. As expected, Storage Ring Beam Fill and Beam Crashes produced radiation at a higher rate than gradual Beam Decay; however, only the latter did not include zero in its 95% confidence interval. By summing for all three accelerator operating modes, a combined yearly DE of 4.3 mRem/yr with a 90% CI of (0.04-8.63) was obtained. These results fall below the DOE reporting level of 10 mRem/yr and suggest repeating the study with improved experimental conditions.

  3. Laser-plasma accelerator and femtosecond photon sources-based ultrafast radiation chemistry and biophysics

    Science.gov (United States)

    Gauduel, Y. A.

    2017-02-01

    The initial distribution of energy deposition triggered by the interaction of ionizing radiations (far UV and X rays, electron, proton and accelerated ions) with molecular targets or integrated biological systems is often decisive for the spatio-temporal behavior of radiation effects that take place on several orders of magnitude. This contribution deals with an interdisciplinary approach that concerns cutting-edge advances on primary radiation events, considering the potentialities of innovating strategies based on ultrafast laser science, from femtosecond photon sources to laser-driven relativistic particles acceleration. Recent advances of powerful TW laser sources (~ 1019 Wcm‑2) and laser-plasma interactions providing ultrashort relativistic particle beams in the energy domain 2.5–150 MeV open exciting opportunities for the development of high-energy radiation femtochemistry (HERF). Early radiation damages being dependent on the survival probability of secondary electrons and radial distribution of short-lived radicals inside ionization clusters, a thorough knowledge of these processes involves the real-time probing of primary events in the temporal range 10‑14–10‑11 s. In the framework of a closed synergy between low-energy radiation femtochemistry (LERF) and the emerging domain of HERF, the paper focuses on early phenomena that occur in the prethermal regime of low-energy secondary electrons, considering very short-lived quantum effects in aqueous environments. A high dose-rate delivered by femtosecond electron beam (~ 1011–1013 Gy s‑1) can be used to investigate early radiation processes in native ionization tracks, down to 10‑12 s and 10‑9 m. We explain how this breakthrough favours the innovating development of real-time nanodosimetry in biologically relevant environments and open new perspectives for spatio-temporal radiation biophysics. The emerging domain of HERF would provide guidance for understanding the specific bioeffects of

  4. Auroral electron distributions within and close to the Saturn kilometric radiation source region

    Science.gov (United States)

    Schippers, P.; Arridge, C. S.; Menietti, J. D.; Gurnett, D. A.; Lamy, L.; Cecconi, B.; Mitchell, D. G.; André, N.; Kurth, W. S.; Grimald, S.; Dougherty, M. K.; Coates, A. J.; Krupp, N.; Young, D. T.

    2011-05-01

    On 17 October 2008, Cassini observed for the first time the electron populations associated with the crossing of a Saturn kilometric radiation source region and its surroundings. These observations allow for the first time the constraint and quantification of the high-latitude acceleration processes, the current systems, and the origin of the low-frequency electromagnetic waves. Enhanced fluxes of field-aligned energetic electrons were measured by the Cassini electron plasma spectrometer in conjunction with unusual intense field-aligned current systems identified using the magnetometer instrument. In the region where downward field-aligned currents were measured, electron data show evidence of two types of upward accelerated electron beams: a broadband energetic (1-100 keV) electron population that is observed throughout the region and a narrow-banded (0.1-1 keV) electron population that is observed sporadically. In the regions where the magnetic field signatures showed evidence for upward field-aligned currents, we observe electron loss cone distributions and some evidence of shell-like distributions. Such nonthermal electron populations are commonly known as a potential free energy source to drive plasma instabilities. In the downward current region, the low-energy and energetic beams are likely the source of the very low frequency emissions. In the upward current region, the shell distribution is identified as a potential source for Saturn kilometric radiation generation via the cyclotron maser instability.

  5. Implicit Solution of Non-Equilibrium Radiation Diffusion Including Reactive Heating Source in Material Energy Equation

    Energy Technology Data Exchange (ETDEWEB)

    Shumaker, D E; Woodward, C S

    2005-05-03

    In this paper, the authors investigate performance of a fully implicit formulation and solution method of a diffusion-reaction system modeling radiation diffusion with material energy transfer and a fusion fuel source. In certain parameter regimes this system can lead to a rapid conversion of potential energy into material energy. Accuracy in time integration is essential for a good solution since a major fraction of the fuel can be depleted in a very short time. Such systems arise in a number of application areas including evolution of a star and inertial confinement fusion. Previous work has addressed implicit solution of radiation diffusion problems. Recently Shadid and coauthors have looked at implicit and semi-implicit solution of reaction-diffusion systems. In general they have found that fully implicit is the most accurate method for difficult coupled nonlinear equations. In previous work, they have demonstrated that a method of lines approach coupled with a BDF time integrator and a Newton-Krylov nonlinear solver could efficiently and accurately solve a large-scale, implicit radiation diffusion problem. In this paper, they extend that work to include an additional heating term in the material energy equation and an equation to model the evolution of the reactive fuel density. This system now consists of three coupled equations for radiation energy, material energy, and fuel density. The radiation energy equation includes diffusion and energy exchange with material energy. The material energy equation includes reaction heating and exchange with radiation energy, and the fuel density equation includes its depletion due to the fuel consumption.

  6. Radiation of planar electromagnetic waves by a line source in anisotropic metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Qiang; Jiang Weixiang; Cui Tiejun, E-mail: tjcui@seu.edu.c [State Key Laboratory of Millimeter Waves, Department of Radio Engineering, Southeast University, Nanjing 210096 (China)

    2010-08-25

    We show experimentally that a line source in an anisotropic metamaterial directly radiates planar electromagnetic waves instead of cylindrical waves, when one component of the permeability tensor approaches zero. The impedance of this material can be perfectly matched to that of free space, which can significantly reduce the reflections between the source and the superstrate, as in traditional highly directive antennas based on zero index metamaterials. Such a unique property determines the two-way propagation of electromagnetic waves excited by a line source, instead of all-way propagation. From this feature, a highly directive emission of electromagnetic waves is achieved using the anisotropic metamaterial with arbitrary shape. We have designed and fabricated the anisotropic metamaterial in the microwave region, and observed the generation of plane waves and their highly directive emission. The proposed plane-wave emission is independent of the shape variance of the anisotropic metamaterial, which can be utilized in the design of conformal antennas.

  7. Modular 20 kW solid state RF amplifier for Indus-2 syncrotron radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Akhilesh, E-mail: ajain@rrcat.gov.in [Raja Ramanna Centre for Advanced Technology, RRCAT, Indore 452013 (India); Hannurkar, P.R.; Sharma, D.K.; Gupta, A.K.; Tiwari, A.K.; Lad, M.; Kumar, R.; Badapanda, M.K.; Gupta, P.D. [Raja Ramanna Centre for Advanced Technology, RRCAT, Indore 452013 (India)

    2012-06-01

    This article presents the design and development of 505.8 MHz modular solid state Radio frequency (RF) amplifier capable of delivering 20 kW continuous RF power. It has been successfully commissioned for serving as the modern RF power source in Indus-2 synchrotron radiation source. For this amplifier, design procedure has been formulated for the solid state amplifier modules, radial combiner, divider, directional coupler and overall system architecture, with specifications suited to RF source for particle accelerator. This article describes underlying design principles and indigenous development of this amplifier, consisting of 400 W amplifier modules, 5 kW 16-port radial combiner/divider and directional couplers. Detail performance characterization of amplifier on component level as well as system level serves as useful data for higher power solid state amplifier designers. Simple design, indigenous technology, high efficiency and ease of fabrication, are the main features of this design.

  8. Saturn Kilometric Radiation Near a Source Center on Day 73, 2008

    Science.gov (United States)

    Menietti, J. D.; Mutel, R. L.; Schippers, P.; Ye, S.-Y.; Santolik, O.; Kurth, W. S.; Gurnett, D. A.; Lamy, L.; Cecconi, B.

    The Cassini spacecraft flew very near a source region of Saturn kilometric radiation (SKR) on day 073 of 2008. This is the second known encounter with a source region at high latitude. The radio and plasma wave instrument, RPWS, observed intense SKR in the extraordinary (X) mode. The electron low-energy spectrometer (ELS) obtained a phase space distribution of sufficient energy and pitch angle resolution to allow growth rate calculations for the observed wave emissions. There is evidence of a shell or horseshoe electron plasma distribution that is unstable to the growth of SKR via the cyclotron maser instability. We present results of these calculations for comparison with a previously reported source region encounter.

  9. Radiation of planar electromagnetic waves by a line source in anisotropic metamaterials

    Science.gov (United States)

    Cheng, Qiang; Jiang, Wei Xiang; Cui, Tie Jun

    2010-08-01

    We show experimentally that a line source in an anisotropic metamaterial directly radiates planar electromagnetic waves instead of cylindrical waves, when one component of the permeability tensor approaches zero. The impedance of this material can be perfectly matched to that of free space, which can significantly reduce the reflections between the source and the superstrate, as in traditional highly directive antennas based on zero index metamaterials. Such a unique property determines the two-way propagation of electromagnetic waves excited by a line source, instead of all-way propagation. From this feature, a highly directive emission of electromagnetic waves is achieved using the anisotropic metamaterial with arbitrary shape. We have designed and fabricated the anisotropic metamaterial in the microwave region, and observed the generation of plane waves and their highly directive emission. The proposed plane-wave emission is independent of the shape variance of the anisotropic metamaterial, which can be utilized in the design of conformal antennas.

  10. Application and development of ion-source technology for radiation-effects testing of electronics

    Science.gov (United States)

    Kalvas, T.; Javanainen, A.; Kettunen, H.; Koivisto, H.; Tarvainen, O.; Virtanen, A.

    2017-09-01

    Studies of heavy-ion induced single event effect (SEE) on space electronics are necessary to verify the operation of the components in the harsh radiation environment. These studies are conducted by using high-energy heavy-ion beams to simulate the radiation effects in space. The ion beams are accelerated as so-called ion cocktails, containing several ion beam species with similar mass-to-charge ratio, covering a wide range of linear energy transfer (LET) values also present in space. The use of cocktails enables fast switching between beam species during testing. Production of these high-energy ion cocktails poses challenging requirements to the ion sources because in most laboratories reaching the necessary beam energies requires very high charge state ions. There are two main technologies producing these beams: The electron beam ion source EBIS and the electron cyclotron resonance ion source ECRIS. The EBIS is most suitable for pulsed accelerators, while ECRIS is most suitable for use with cyclotrons, which are the most common accelerators used in these applications. At the Accelerator Laboratory of the University of Jyväskylä (JYFL), radiation effects testing is currently performed using a K130 cyclotron and a 14 GHz ECRIS at a beam energy of 9.3 MeV/u. A new 18 GHz ECRIS, pushing the limits of the normal conducting ECR technology is under development at JYFL. The performances of existing 18 GHz ion sources have been compared, and based on this analysis, a 16.2 MeV/u beam cocktail with 1999 MeV 126Xe44+ being the most challenging component to has been chosen for development at JYFL. The properties of the suggested beam cocktail are introduced and discussed.

  11. LIGHT SOURCE: Physical design of a 10 MeV LINAC for polymer radiation processing

    Science.gov (United States)

    Feng, Guang-Yao; Pei, Yuan-Ji; Wang, Lin; Zhang, Shan-Cai; Wu, Cong-Feng; Jin, Kai; Li, Wei-Min

    2009-06-01

    In China, polymer radiation processing has become one of the most important processing industries. The radiation processing source may be an electron beam accelerator or a radioactive source. Physical design of an electron beam facility applied for radiation crosslinking is introduced in this paper because of it's much higher dose rate and efficiency. Main part of this facility is a 10 MeV travelling wave electron linac with constant impedance accelerating structure. A start to end simulation concerning the linac is reported in this paper. The codes Opera-3d, Poisson-superfish and Parmela are used to describe electromagnetic elements of the accelerator and track particle distribution from the cathode to the end of the linac. After beam dynamic optimization, wave phase velocities in the structure have been chosen to be 0.56, 0.9 and 0.999 respectively. Physical parameters about the main elements such as DC electron gun, iris-loaded periodic structure, solenoids, etc, are presented. Simulation results proves that it can satisfy the industrial requirement. The linac is under construction. Some components have been finished. Measurements proved that they are in a good agreement with the design values.

  12. Generalized source Finite Volume Method for radiative transfer equation in participating media

    Science.gov (United States)

    Zhang, Biao; Xu, Chuan-Long; Wang, Shi-Min

    2017-03-01

    Temperature monitoring is very important in a combustion system. In recent years, non-intrusive temperature reconstruction has been explored intensively on the basis of calculating arbitrary directional radiative intensities. In this paper, a new method named Generalized Source Finite Volume Method (GSFVM) was proposed. It was based on radiative transfer equation and Finite Volume Method (FVM). This method can be used to calculate arbitrary directional radiative intensities and is proven to be accurate and efficient. To verify the performance of this method, six test cases of 1D, 2D, and 3D radiative transfer problems were investigated. The numerical results show that the efficiency of this method is close to the radial basis function interpolation method, but the accuracy and stability is higher than that of the interpolation method. The accuracy of the GSFVM is similar to that of the Backward Monte Carlo (BMC) algorithm, while the time required by the GSFVM is much shorter than that of the BMC algorithm. Therefore, the GSFVM can be used in temperature reconstruction and improvement on the accuracy of the FVM.

  13. Physical conditions for sources radiating a cosh-Gaussian model beam

    Institute of Scientific and Technical Information of China (English)

    LI Jia

    2011-01-01

    Based on the coherence theory of diffracted optical field and the model for partially coherent beams, analytical expressions for the cross-spectral density and the irradiance spectral density in the far zone are derived, respectively. Utilizing the theoretical model of radiation from secondary planar sources, the physical conditions for sources generating a cosh-Gaussian (CHG) beam are investigated. Analytical results demonstrate that the parametric conditions strongly depend on the coherence property of sources. When almost coherence property is satisfied in the source plane, the conditions are the same as those for fundamental Gaussian beams; when partial coherence or almost incoherence property is satisfied in the spatial source plane, the conditions are the same as those for Gaussian-Schell model beams. The results also indicate that the variance of cosine parameters has no influence on the conditions. Our results may provide potential applications for some investigations such as the modulations of cosh-Gaussian beams and the designs of source beam parameters.

  14. Roadmap for the international, accelerator-based neutrino programme

    Energy Technology Data Exchange (ETDEWEB)

    Cao, J. [Beijing, Inst. High Energy Phys. (China); de Gouvêa, A. [Northwestern Univ., Evanston, IL (United States); Duchesneau, D. [CNRS/IN2P3. Univ. Paris (France). Observatoire de Paris. AstroParticule et Cosmologie (APC); Geer, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Gomes, R. [Federal University of Goias (Brazil); Kim, S. B. [Seoul National Univ. (Korea, Republic of); Kobayashi, T. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Long, K. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL); Maltoni, M. [Autonomous Univ. of Madrid (Spain); Mezzetto, M. [Univ. of Padua (Italy); Mondal, N. [Tata Inst. of Fundamental Research, Bombay (India); Shiozawa, M. [Univ. of Tokyo (Japan); Sobczyk, J. [Univ. of Wroclaw (Poland); Tanaka, H. A. [TRIUMF, Vancouver, BC (Canada); Wascko, M. [Imperial College, London (United Kingdom); Zeller, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-04-26

    In line with its terms of reference the ICFA Neutrino Panel has developed a roadmap for the international, accelerator-based neutrino programme. A "roadmap discussion document" was presented in May 2016 taking into account the peer-group-consultation described in the Panel's initial report. The "roadmap discussion document" was used to solicit feedback from the neutrino community---and more broadly, the particle- and astroparticle-physics communities---and the various stakeholders in the programme. The roadmap, the conclusions and recommendations presented in this document take into account the comments received following the publication of the roadmap discussion document. With its roadmap the Panel documents the approved objectives and milestones of the experiments that are presently in operation or under construction. Approval, construction and exploitation milestones are presented for experiments that are being considered for approval. The timetable proposed by the proponents is presented for experiments that are not yet being considered formally for approval. Based on this information, the evolution of the precision with which the critical parameters governinger the neutrino are known has been evaluated. Branch or decision points have been identified based on the anticipated evolution in precision. The branch or decision points have in turn been used to identify desirable timelines for the neutrino-nucleus cross section and hadro-production measurements that are required to maximise the integrated scientific output of the programme. The branch points have also been used to identify the timeline for the R&D required to take the programme beyond the horizon of the next generation of experiments. The theory and phenomenology programme, including nuclear theory, required to ensure that maximum benefit is derived from the experimental programme is also discussed.

  15. Subpanel on accelerator-based neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    Neutrinos are among nature`s fundamental constituents, and they are also the ones about which we know least. Their role in the universe is widespread, ranging from the radioactive decay of a single atom to the explosions of supernovae and the formation of ordinary matter. Neutrinos might exhibit a striking property that has not yet been observed. Like the back-and-forth swing of a pendulum, neutrinos can oscillate to-and-from among their three types (or flavors) if nature provides certain conditions. These conditions include neutrinos having mass and a property called {open_quotes}mixing.{close_quotes} The phenomenon is referred to as neutrino oscillations. The questions of the origin of neutrino mass and mixing among the neutrino flavors are unsolved problems for which the Standard Model of particle physics holds few clues. It is likely that the next critical step in answering these questions will result from the experimental observation of neutrino oscillations. The High Energy Physics Advisory Panel (HEPAP) Subpanel on Accelerator-Based Neutrino Oscillation Experiments was charged to review the status and discovery potential of ongoing and proposed accelerator experiments on neutrino oscillations, to evaluate the opportunities for the U.S. in this area of physics, and to recommend a cost-effective plan for pursuing this physics, as appropriate. The complete charge is provided in Appendix A. The Subpanel studied these issues over several months and reviewed all the relevant and available information on the subject. In particular, the Subpanel reviewed the two proposed neutrino oscillation programs at Fermi National Accelerator Laboratory (Fermilab) and at Brookhaven National Laboratory (BNL). The conclusions of this review are enumerated in detail in Chapter 7 of this report. The recommendations given in Chapter 7 are also reproduced in this summary.

  16. Experimental Verification of Isotropic Radiation from a Coherent Dipole Source via Electric-Field-Driven LC Resonator Metamaterials

    Science.gov (United States)

    Tichit, Paul-Henri; Burokur, Shah Nawaz; Qiu, Cheng-Wei; de Lustrac, André

    2013-09-01

    It has long been conjectured that isotropic radiation by a simple coherent source is impossible due to changes in polarization. Though hypothetical, the isotropic source is usually taken as the reference for determining a radiator’s gain and directivity. Here, we demonstrate both theoretically and experimentally that an isotropic radiator can be made of a simple and finite source surrounded by electric-field-driven LC resonator metamaterials designed by space manipulation. As a proof-of-concept demonstration, we show the first isotropic source with omnidirectional radiation from a dipole source (applicable to all distributed sources), which can open up several possibilities in axion electrodynamics, optical illusion, novel transformation-optic devices, wireless communication, and antenna engineering. Owing to the electric- field-driven LC resonator realization scheme, this principle can be readily applied to higher frequency regimes where magnetism is usually not present.

  17. Submicron focusing of XUV radiation from a laser plasma source using a multilayer Laue lens

    Science.gov (United States)

    Reese, M.; Schäfer, B.; Großmann, P.; Bayer, A.; Mann, K.; Liese, T.; Krebs, H. U.

    2011-01-01

    The focusing properties of a one-dimensional multilayer Laue lens (MLL) were investigated using monochromatic soft X-ray radiation from a table-top, laser-produced plasma source. The MLL was fabricated by a focused ion beam (FIB) structuring of pulsed laser deposited ZrO2/Ti multilayers. This novel method offers the potential to overcome limitations encountered in electron lithographic processes. Utilizing this multilayer Laue lens, a line focus of XUV radiation from a laser-induced plasma in a nitrogen gas puff target could be generated. The evaluated focal length is close to the designed value of 220 μm for the measurement wavelength of 2.88 nm. Divergence angle and beam waist diameter are measured by a moving knife edge and a far-field experiment, determining all relevant second-order moments based beam parameters. The waist diameter has been found to be approximately 370 nm (FWHM).

  18. Exact inhomogeneous cosmologies whose source is a radiation-matter mixture with consistent thermodynamics

    CERN Document Server

    Sussman, R A; Sussman, Roberto A.; Pavon, Diego

    1999-01-01

    We derive a new class of exact solutions of Einstein's equations providing a physically plausible hydrodynamical description of cosmological matter in the radiative era ($10^6 K > T > 10^3 K$), between nucleosynthesis and decoupling. The solutions are characterized by the Lemaître-Tolman -Bondi metric with a viscous fluid source, subjected to the following conditions: (a) the equilibrium state variables satisfy the equation of state of a mixture of an ultra-relativistic and a non-relativistic ideal gases, where the internal energy of the latter has been neglected, (b) the particle numbers of the mixture components are independently conserved, (c) the viscous stress is consistent with the transport equation and entropy balance law of Extended Irreversible Thermodynamics, with the coefficient of shear viscosity provided by Kinetic Theory for the `radiative gas' model. The fulfilment of (a), (b) and (c) restricts initial conditions in terms of an initial value function, fluctuations of photon entropy per baryon...

  19. Software development for studies of diffuse scattering using CCD-detectors and synchrotron radiation sources

    CERN Document Server

    Paulmann, C; Bismayer, U

    2001-01-01

    A graphical-user-interface based software system was developed to cover advanced data processing requirements which arise from studies of diffuse scattering in disordered minerals using synchrotron radiation sources and CCD-detectors. The software includes interfaces to standard applications, procedures for numerical processing of large data sets, corrections for sample external scattering and detector-specific distortions, different scaling options to correct the data set against the varying primary beam intensity as well as procedures to reconstruct arbitrary slices in reciprocal space on a regular grid. The software system was successfully applied in studies of diffuse scattering in disordered REE-doped germanates, phase-transition studies of synthetic titanite and studies of the thermal recrystallization behaviour of radiation-damaged (metamict) minerals.

  20. Measurement of Acoustic Intensity Distribution and Radiation Power of Flat-Plate Phased-Array Sound Source

    Science.gov (United States)

    Yokoyama, Tomoki; Takahashi, Kumiko; Seki, Daizaburou; Hasegawa, Akio

    2002-05-01

    The acoustic intensity distribution and radiation power of a flat-plate phased-array sound source consisting of Tonpilz-type transducers were measured. This study shows that the active acoustic intensity is skewed in the direction of wave propagation. In addition, it clarifies that if the measurement is carried out in the immediate vicinity of the sound source, the reactive acoustic intensity distribution is effective for identifying the positions of the individual sound source elements. Experimental values of active radiation power agree well with theoretical values. Conversely, experimental values of reactive radiation power do not agree with theoretical values; it is clear that they fluctuate significantly with distance from the radiating surface. The reason for this is explained in the case of a point sound source.

  1. Parallax diagnostics of radiation source geometric dilution for iron opacity experiments

    CERN Document Server

    Nagayama, T; Loisel, G; Rochau, G A; Falcon, R E

    2014-01-01

    Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions [J.E. Bailey et al., Phys. Plasmas 16, 058101 (2009)]. The iron sample is placed on top of the Sandia National Laboratories z-pinch dynamic hohlraum (ZPDH) radiation source. The samples are heated to 150 - 200 eV electron temperatures and 7e21 - 4e22 e/cc electron densities by the ZPDH radiation and backlit at its stagnation [T. Nagayama et al., Phys. Plasmas 21, 056502 (2014)]. The backlighter attenuated by the heated sample plasma is measured by four spectrometers along +/- 9 degree with respect to the z-pinch axis to infer the sample iron opacity. Here we describe measurements of the source-to-sample distance that exploit the parallax of spectrometers that view the half-moon-shaped sample from +/-9 degree. The measured sample temperature decreases with increased source-to-sample distance. This distance must be taken into account for understanding the sample heating.

  2. Synchrotron radiation study of the uranium chemical species electrodeposited for alpha spectrometry sources

    Energy Technology Data Exchange (ETDEWEB)

    Burciaga V, D. C.; Mendez, C. G.; Esparza P, H.; Fuentes C, L.; Fuentes M, L.; Montero C, M. E. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico); Beesley, A. M. [School of Chemical Engineering and Analytical Science, University of Manchester, Oxford Road, M13 9PL Manchester (United Kingdom); Crespo, M. T., E-mail: elena.montero@cimav.edu.m [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Metrologia de Radiaciones Ionizantes, Avda. Complutense 22, 28040 Madrid (Spain)

    2011-02-15

    Alpha spectrometry (As) with semiconductor detectors has applications in nuclear decay data measurements, environmental, geological and nuclear wastes studies and other works requiring determination of actinide and other alpha emitter contents. In order to obtain accurate measurements by producing good resolution alpha spectra, As sources must be thin and uniform. As sources produced by electrodeposition consist of a radioactive deposit onto a metallic substrate (cathode of the electrolytic cell). Natural U sources prepared by the Hallstadius method have co-deposited Pt, originated from the dissolution of the anode during the electrodeposition. A recent work published else-where has reported a study on the morphology and spatial distribution of the U/Pt deposits with the related chemical speciation of U, using scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and X-ray absorption fine structure. The purpose of this work is to explain the structure of the Pt/U deposits. We have obtained new spectra of the U L III edge X-ray absorption fine structure by total electron yield at Stanford Synchrotron radiation light source, Bl 2-3. Grazing incidence X-ray diffraction (Gi-XRD) patterns were obtained at Stanford Synchrotron radiation light source, Bl 11-3. Gi-XRD patterns show a bimodal distribution of grain sizes of Pt, with dimensions {approx} 5 and 20 nm; schoepite diffraction signals suggest grain dimensions of {approx} 5 nm, i.e. with low crystallization. X-ray absorption fine structure spectra were fitted assuming two different structures: uranyl hydroxide and schoepite, and results were compared. U-U path shows low intensity that also may be a result of low crystallization. (Author)

  3. Photon Conserving Radiative Transfer around Point Sources in multi-dimensional Numerical Cosmology

    CERN Document Server

    Abel, T; Madau, P; Abel, Tom; Norman, Michael L.; Madau, Piero

    1998-01-01

    Many questions in physical cosmology regarding the thermal and ionization history of the intergalactic medium are now successfully studied with the help of cosmological hydrodynamical simulations. Here we present a numerical method that solves the radiative transfer around point sources within a three dimensional cartesian grid. The method is energy conserving independently of resolution: this ensures the correct propagation speeds of ionization fronts. We describe the details of the algorithm, and compute as first numerical application the ionized region surrounding a mini-quasar in a cosmological density field at z=7.

  4. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    OpenAIRE

    2014-01-01

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 meter off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu2+ phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O2, N2O and SO2 are carried...

  5. On-demand source of maximally entangled photon pairs using the biexciton-exciton radiative cascade

    Science.gov (United States)

    Winik, R.; Cogan, D.; Don, Y.; Schwartz, I.; Gantz, L.; Schmidgall, E. R.; Livneh, N.; Rapaport, R.; Buks, E.; Gershoni, D.

    2017-06-01

    We perform full time-resolved tomographic measurements of the polarization state of pairs of photons emitted during the radiative cascade of the confined biexciton in a semiconductor quantum dot. The biexciton was deterministically initiated using a π -area pulse into the biexciton two-photon absorption resonance. Our measurements demonstrate that the polarization states of the emitted photon pair are maximally entangled. We show that the measured degree of entanglement depends solely on the temporal resolution by which the time difference between the emissions of the photon pair is determined. A route for fabricating an on-demand source of maximally polarization entangled photon pairs is thereby provided.

  6. Novel radiation sources using relativistic electrons from infrared to x-rays

    CERN Document Server

    Rullhusen, P; Dhez, P

    1998-01-01

    The purpose of this book is to give a description of the state of the art in theoretical and experimental work achieved in radiation source development. It summarizes clearly and comprehensibly, the basic physical aspects needed to understand the phenomena, and also provides the interested reader with sufficient literature to be able to follow the development in more detail. In addition, it contains a unified view of most theoretical effects and their common properties. The most recent developments as well as references to further work can be found in this volume. In many cases, review article

  7. Physiologically gated microbeam radiation using a field emission x-ray source array

    Energy Technology Data Exchange (ETDEWEB)

    Chtcheprov, Pavel, E-mail: PavelC@unc.edu, E-mail: zhou@email.unc.edu [Department of Biomedical Engineering, University of North Carolina, 152 MacNider Hall, Campus Box 7575, Chapel Hill, North Carolina 27599 (United States); Burk, Laurel; Inscoe, Christina; Ger, Rachel; Hadsell, Michael; Lu, Jianping [Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599 (United States); Yuan, Hong [Department of Radiology, University of North Carolina, 2006 Old Clinic, CB #7510, Chapel Hill, North Carolina 27599 (United States); Zhang, Lei [Department of Applied Physical Sciences, University of North Carolina, Chapman Hall, CB#3216, Chapel Hill, North Carolina 27599 (United States); Chang, Sha [Department of Radiation Oncology, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 (United States); Zhou, Otto, E-mail: PavelC@unc.edu, E-mail: zhou@email.unc.edu [Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 (United States)

    2014-08-15

    Purpose: Microbeam radiation therapy (MRT) uses narrow planes of high dose radiation beams to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000 Gy of peak entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during treatment can lead to significant movement of microbeam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), which reduces the effectiveness of MRT. Recently, the authors have demonstrated the feasibility of generating microbeam radiation for small animal treatment using a carbon nanotube (CNT) x-ray source array. The purpose of this study is to incorporate physiological gating to the CNT microbeam irradiator to minimize motion-induced microbeam blurring. Methods: The CNT field emission x-ray source array with a narrow line focal track was operated at 160 kVp. The x-ray radiation was collimated to a single 280 μm wide microbeam at entrance. The microbeam beam pattern was recorded using EBT2 Gafchromic{sup ©} films. For the feasibility study, a strip of EBT2 film was attached to an oscillating mechanical phantom mimicking mouse chest respiratory motion. The servo arm was put against a pressure sensor to monitor the motion. The film was irradiated with three microbeams under gated and nongated conditions and the full width at half maximums and PVDRs were compared. An in vivo study was also performed with adult male athymic mice. The liver was chosen as the target organ for proof of concept due to its large motion during respiration compared to other organs. The mouse was immobilized in a specialized mouse bed and anesthetized using isoflurane. A pressure sensor was attached to a mouse's chest to monitor its respiration. The output signal triggered the electron extraction voltage of the field emission source such that x-ray was generated only

  8. Physiologically gated microbeam radiation using a field emission x-ray source array.

    Science.gov (United States)

    Chtcheprov, Pavel; Burk, Laurel; Yuan, Hong; Inscoe, Christina; Ger, Rachel; Hadsell, Michael; Lu, Jianping; Zhang, Lei; Chang, Sha; Zhou, Otto

    2014-08-01

    Microbeam radiation therapy (MRT) uses narrow planes of high dose radiation beams to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000 Gy of peak entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during treatment can lead to significant movement of microbeam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), which reduces the effectiveness of MRT. Recently, the authors have demonstrated the feasibility of generating microbeam radiation for small animal treatment using a carbon nanotube (CNT) x-ray source array. The purpose of this study is to incorporate physiological gating to the CNT microbeam irradiator to minimize motion-induced microbeam blurring. The CNT field emission x-ray source array with a narrow line focal track was operated at 160 kVp. The x-ray radiation was collimated to a single 280 μm wide microbeam at entrance. The microbeam beam pattern was recorded using EBT2 Gafchromic(©) films. For the feasibility study, a strip of EBT2 film was attached to an oscillating mechanical phantom mimicking mouse chest respiratory motion. The servo arm was put against a pressure sensor to monitor the motion. The film was irradiated with three microbeams under gated and nongated conditions and the full width at half maximums and PVDRs were compared. An in vivo study was also performed with adult male athymic mice. The liver was chosen as the target organ for proof of concept due to its large motion during respiration compared to other organs. The mouse was immobilized in a specialized mouse bed and anesthetized using isoflurane. A pressure sensor was attached to a mouse's chest to monitor its respiration. The output signal triggered the electron extraction voltage of the field emission source such that x-ray was generated only during a portion of the mouse

  9. What is the best proton energy for accelerator-based BNCT using the 7Li(p,n)7Be reaction?

    Science.gov (United States)

    Allen, D A; Beynon, T D

    2000-05-01

    With a growing interest in the use of accelerator-based epithermal neutron sources for BNCT programs, in particular those based upon the 7Li(p,n)7Be reaction, there is a need to address the question of "what is the best proton energy to use?" This paper considers this question by using radiation transport calculations to investigate a range of proton energies from 2.15 to 3.5 MeV and a range of moderator sizes. This study has moved away completely from the use of empty therapy beam parameters and instead defines the beam quality and optimizes the moderator design using widely accepted in-phantom treatment planning figures of merit. It is concluded that up to a proton energy of about 2.8 MeV there is no observed variation in the achievable therapy beam quality, but a price is paid in terms of treatment time for not choosing the upper limit of this range. For higher proton energies, the beam quality falls, but with no improvement in treatment time for optimum configurations.

  10. Orbit correction using an eigenvector method with constraints for synchrotron radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Kentaro [Photon Factory, High Energy Accelerator Research Organization, 1-1, Oho, Tsukuba, Ibaraki 305-0801 (Japan)], E-mail: kentaro.harada@kek.jp; Obina, Takashi; Kobayashi, Yukinori [Photon Factory, High Energy Accelerator Research Organization, 1-1, Oho, Tsukuba, Ibaraki 305-0801 (Japan); Nakamura, Norio; Takaki, Hiroyuki; Sakai, Hiroshi [Institute for Solid State Physics, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

    2009-06-11

    An eigenvector method with constraints (EVC) is proposed as a new orbit correction scheme for synchrotron light sources. EVC efficiently corrects the global orbit in a storage ring, and can simultaneously perform exact correction of local orbits without deterioration of the global orbit. To demonstrate the advantages of EVC over the ordinary eigenvector method (EV), we carried out experimental studies at the Photon Factory storage ring (PF-ring) and the Photon Factory Advanced Ring (PF-AR) at the High Energy Accelerator Research Organization (KEK). The performance of EVC was systematically examined at PF-ring and PF-AR. The experimental results agreed well with the simulated ones. Consequently, we confirmed that EVC easily realized orbit correction for both global and local orbits, and that it was very effective for the beam stabilization of synchrotron radiation (SR) sources.

  11. Orbit correction using an eigenvector method with constraints for synchrotron radiation sources

    Science.gov (United States)

    Harada, Kentaro; Obina, Takashi; Kobayashi, Yukinori; Nakamura, Norio; Takaki, Hiroyuki; Sakai, Hiroshi

    2009-06-01

    An eigenvector method with constraints (EVC) is proposed as a new orbit correction scheme for synchrotron light sources. EVC efficiently corrects the global orbit in a storage ring, and can simultaneously perform exact correction of local orbits without deterioration of the global orbit. To demonstrate the advantages of EVC over the ordinary eigenvector method (EV), we carried out experimental studies at the Photon Factory storage ring (PF-ring) and the Photon Factory Advanced Ring (PF-AR) at the High Energy Accelerator Research Organization (KEK). The performance of EVC was systematically examined at PF-ring and PF-AR. The experimental results agreed well with the simulated ones. Consequently, we confirmed that EVC easily realized orbit correction for both global and local orbits, and that it was very effective for the beam stabilization of synchrotron radiation (SR) sources.

  12. Theoretical study on active control of sound radiation based on planar sound source

    Institute of Scientific and Technical Information of China (English)

    CHENKe'an; GaryH.Koopmann

    2003-01-01

    Active control of low frequency sound radiation using planar secondary sources is theoretically investigated. The primary sound field originates from a vibrating panel and the planar secondary sources are modeled as simply supported rectangular panels in an infinite baffle. The sound power of the primary and secondary panels is calculated, and then a series of formulae are derived to obtain the optimum reduction in sound power. Finally, active reduction for a number of secondary panel arrangements is examined, it is concluded that when the modal distribution of the secondary panel does coincide with that of the primary panel, one secondary panel is sufficient. Otherwise four secondary panels can guarantee considerable reduction in sound power over entire frequency range of interest.

  13. An effect of stimulated radiation processes on radio emission from extended sources

    CERN Document Server

    Prigara, F V

    2003-01-01

    Both the standard theory of thermal radio emission and the synchrotron theory encounter some difficulties. The most crucial for the former one is nonpossibility to explain the radio spectrum of Venus in the decimeter range (Ksanfomality 1985). The radio spectra of planetary nebulae at high frequencies also are not comfortably consistent with the standard theory (Siodmiak & Tylenda 2001). Here we show that the account for an induced character of radiation processes sufficiently improves the predictions of the standard theory. Moreover, the developed here theory of radio emission from non-uniform gas gives the radio spectra of extended sources, such as supernova remnants and radio galaxies, which are normally attributed to the synchrotron emission. It is important, in this aspect, that the synchrotron self-absorption produces a change in the polarization position angle across the spectral peak. No such a change was detected in gigahertz-peaked spectrum sources (Mutoh et al. 2002). Besides, the flat or sligh...

  14. The enhanced volume source boundary point method for the calculation of acoustic radiation problem

    Institute of Scientific and Technical Information of China (English)

    WANG Xiufeng; CHEN Xinzhao; WANG Youcheng

    2003-01-01

    The Volume Source Boundary Point Method (VSBPM) is greatly improved so that it will speed up the VSBPM's solution of the acoustic radiation problem caused by the vibrating body. The fundamental solution provided by Helmholtz equation is enforced in a weighted residual sense over a tetrahedron located on the normal line of the boundary node to replace the coefficient matrices of the system equation. Through the enhanced volume source boundary point analysis of various examples and the sound field of a vibrating rectangular box in a semi-anechoic chamber, it has revealed that the calculating speed of the EVSBPM is more than 10 times faster than that of the VSBPM while it works on the aspects of its calculating precision and stability, adaptation to geometric shape of vibrating body as well as its ability to overcome the non-uniqueness problem.

  15. Safety Analysis Report for Primary Capsule of Ir-192 Radiation Source

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. C.; Bang, K. S.; Choi, W. S.; Seo, K. S.; Son, K. J.; Park, W. J

    2008-12-15

    All of the source capsules to transport a special form radioactive material should be designed and fabricated in accordance with the design criteria prescribed in IAEA standards and domestic regulations. The objective of this project is to prove the safety of a primary capsule for Ir-192 radiation source which produced in the HANARO. The safety tests of primary capsules were carried out for the impact, percussion and heat conditions. And leakage tests were carried out before and after the each tests. The capsule showed slight scratches and their deformations were not found after each tests. It also met the allowable limits of leakage rate after each test. Therefore, it has been verified that the capsule was designed and fabricated to meet all requirements for the special form radioactive materials.

  16. Measurement of the energy and power radiated by a pulsed blackbody x-ray source

    Directory of Open Access Journals (Sweden)

    H. C. Ives

    2006-11-01

    Full Text Available We have developed a diagnostic system that measures the spectrally integrated (i.e. the total energy and power radiated by a pulsed blackbody x-ray source. The total-energy-and-power (TEP diagnostic system is optimized for blackbody temperatures between 50 and 350 eV. The system can view apertured sources that radiate energies and powers as high as 2 MJ and 200 TW, respectively, and has been successfully tested at 0.84 MJ and 73 TW on the Z pulsed-power accelerator. The TEP system consists of two pinhole arrays, two silicon-diode detectors, and two thin-film nickel bolometers. Each of the two pinhole arrays is paired with a single silicon diode. Each array consists of a 38×38 square array of 10-μm-diameter pinholes in a 50-μm-thick tantalum plate. The arrays achromatically attenuate the x-ray flux by a factor of ∼1800. The use of such arrays for the attenuation of soft x rays was first proposed by Turner and co-workers [Rev. Sci. Instrum. 70, 656 (1999RSINAK0034-674810.1063/1.1149385]. The attenuated flux from each array illuminates its associated diode; the diode’s output current is recorded by a data-acquisition system with 0.6-ns time resolution. The arrays and diodes are located 19 and 24 m from the source, respectively. Because the diodes are designed to have an approximately flat spectral sensitivity, the output current from each diode is proportional to the x-ray power. The nickel bolometers are fielded at a slightly different angle from the array-diode combinations, and view (without pinhole attenuation the same x-ray source. The bolometers measure the total x-ray energy radiated by the source and—on every shot—provide an in situ calibration of the array-diode combinations. Two array-diode pairs and two bolometers are fielded to reduce random uncertainties. An analytic model (which accounts for pinhole-diffraction effects of the sensitivity of an array-diode combination is presented.

  17. Coupling of MASH-MORSE Adjoint Leakages with Space- and Time-Dependent Plume Radiation Sources

    Energy Technology Data Exchange (ETDEWEB)

    Slater, C.O.

    2001-04-20

    In the past, forward-adjoint coupling procedures in air-over-ground geometry have typically involved forward fluences arising from a point source a great distance from a target or vehicle system. Various processing codes were used to create localized forward fluence files that could be used to couple with the MASH-MORSE adjoint leakages. In recent years, radiation plumes that result from reactor accidents or similar incidents have been modeled by others, and the source space and energy distributions as a function of time have been calculated. Additionally, with the point kernel method, they were able to calculate in relatively quick fashion free-field radiation doses for targets moving within the fluence field or for stationary targets within the field, the time dependence for the latter case coming from the changes in position, shape, source strength, and spectra of the plume with time. The work described herein applies the plume source to the MASH-MORSE coupling procedure. The plume source replaces the point source for generating the forward fluences that are folded with MASH-MORSE adjoint leakages. Two types of source calculations are described. The first is a ''rigorous'' calculation using the TORT code and a spatially large air-over-ground geometry. For each time step desired, directional fluences are calculated and are saved over a predetermined region that encompasses a structure within which it is desired to calculate dose rates. Processing codes then create the surface fluences (which may include contributions from radiation sources that deposit on the roof or plateout) that will be coupled with the MASH-MORSE adjoint leakages. Unlike the point kernel calculations of the free-field dose rates, the TORT calculations in practice include the effects of ground scatter on dose rates and directional fluences, although the effects may be underestimated or overestimated because of the use of necessarily coarse mesh and quadrature in order to

  18. Response of a hybrid pixel detector (MEDIPIX3) to different radiation sources for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Chumacero, E. Miguel; De Celis Alonso, B.; Martínez Hernández, M. I.; Vargas, G.; Moreno Barbosa, E., E-mail: emoreno.emb@gmail.com [Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Rio Verde, Puebla (Mexico); Moreno Barbosa, F. [Hospital General del Sur Hospital de la Mujer, Puebla (Mexico)

    2014-11-07

    The development in semiconductor CMOS technology has enabled the creation of sensitive detectors for a wide range of ionizing radiation. These devices are suitable for photon counting and can be used in imaging and tomography X-ray diagnostics. The Medipix[1] radiation detection system is a hybrid silicon pixel chip developed for particle tracking applications in High Energy Physics. Its exceptional features (high spatial and energy resolution, embedded ultra fast readout, different operation modes, etc.) make the Medipix an attractive device for applications in medical imaging. In this work the energy characterization of a third-generation Medipix chip (Medipix3) coupled to a silicon sensor is presented. We used different radiation sources (strontium 90, iron 55 and americium 241) to obtain the response curve of the hybrid detector as a function of energy. We also studied the contrast of the Medipix as a measure of pixel noise. Finally we studied the response to fluorescence X rays from different target materials (In, Pd and Cd) for the two data acquisition modes of the chip; single pixel mode and charge summing mode.

  19. Astrophysical Ionizing Radiation and the Earth: A Brief Review and Census of Intermittent Intense Sources

    CERN Document Server

    Melott, Adrian L

    2011-01-01

    Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere: on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. We enumerate the known sources of radiation and characterize their intensities at the Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval", our best estimate of how often a major extinction-level event is proba...

  20. Measurement, analysis and correction of the closed orbit distortion in Indus-2 synchrotron radiation source

    Indian Academy of Sciences (India)

    Riyasat Husain; A D Ghodke; Surendra Yadav; A C Holikatti; R P Yadav; P Fatnani; T A Puntambekar; P R Hannurkar

    2013-02-01

    The paper presents the measurement, analysis and correction of closed orbit distortion (COD) in Indus-2 at 550 MeV injection energy and 2 GeV synchrotron radiation user run energy. The measured COD was analysed and fitted to understand major sources of errors in terms of the effective quadrupole misalignments. The rms COD was corrected down to less than 0.6 mm in both horizontal and vertical planes. A golden orbit was set for the operating synchrotron radiation beamlines. With COD correction, the injection efficiency at 550 MeV was improved by ∼ 50% and the beam lifetime at 2 GeV was increased by ∼8 h. In this paper, the method of global COD correction based on singular value decomposition (SVD) of the orbit response matrix is described. Results for the COD correction in both horizontal and vertical planes at 550 MeV injection energy and at 2 GeV synchrotron radiation user run energy are discussed.

  1. Active control of sound radiation from a vibrating rectangular panel by sound sources and vibration inputs - An experimental comparison

    Science.gov (United States)

    Fuller, C. R.; Hansen, C. H.; Snyder, S. D.

    1991-01-01

    Active control of sound radiation from a rectangular panel by two different methods has been experimentally studied and compared. In the first method a single control force applied directly to the structure is used with a single error microphone located in the radiated acoustic field. Global attenuation of radiated sound was observed to occur by two main mechanisms. For 'on-resonance' excitation, the control force had the effect of increasing the total panel input impedance presented to the nosie source, thus reducing all radiated sound. For 'off-resonance' excitation, the control force tends not significantly to modify the panel total response amplitude but rather to restructure the relative phases of the modes leading to a more complex vibration pattern and a decrease in radiation efficiency. For acoustic control, the second method, the number of acoustic sources required for global reduction was seen to increase with panel modal order. The mechanism in this case was that the acoustic sources tended to create an inverse pressure distribution at the panel surface and thus 'unload' the panel by reducing the panel radiation impedance. In general, control by structural inputs appears more effective than control by acoustic sources for structurally radiated noise.

  2. Accelerator-based techniques for the support of senior-level undergraduate physics laboratories

    Science.gov (United States)

    Williams, J. R.; Clark, J. C.; Isaacs-Smith, T.

    2001-07-01

    Approximately three years ago, Auburn University replaced its aging Dynamitron accelerator with a new 2MV tandem machine (Pelletron) manufactured by the National Electrostatics Corporation (NEC). This new machine is maintained and operated for the University by Physics Department personnel, and the accelerator supports a wide variety of materials modification/analysis studies. Computer software is available that allows the NEC Pelletron to be operated from a remote location, and an Internet link has been established between the Accelerator Laboratory and the Upper-Level Undergraduate Teaching Laboratory in the Physics Department. Additional software supplied by Canberra Industries has also been used to create a second Internet link that allows live-time data acquisition in the Teaching Laboratory. Our senior-level undergraduates and first-year graduate students perform a number of experiments related to radiation detection and measurement as well as several standard accelerator-based experiments that have been added recently. These laboratory exercises will be described, and the procedures used to establish the Internet links between our Teaching Laboratory and the Accelerator Laboratory will be discussed.

  3. Doppler Broadening Analysis of Steel Specimens Using Accelerator Based In Situ Pair Production

    Science.gov (United States)

    Makarashvili, V.; Wells, D. P.; Roy, A. K.

    2009-03-01

    Positron Annihilation Spectroscopy (PAS) techniques can be utilized as a sensitive probe of defects in materials. Studying these microscopic defects is very important for a number of industries in order to predict material failure or structural integrity. We have been developing gamma-induced pair-production techniques to produce positrons in thick samples (˜4-40 g/cm2, or ˜0.5-5 cm in steel). These techniques are called 'Accelerator-based Gamma-induced Positron Annihilation Spectroscopy' (AG-PAS). We have begun testing the capabilities of this technique for imaging of defect densities in thick structural materials. As a first step, a linear accelerator (LINAC) was employed to produce photon beams by stopping 15 MeV electrons in a 1 mm thick tungsten converter. The accelerator is capable of operating with 30-60 ns pulse width, up to 200 mA peak current at 1 kHz repetition rate. The highly collimated bremsstrahlung beam impinged upon our steel tensile specimens, after traveling through a 1.2 m thick concrete wall. Annihilation radiation was detected by a well-shielded and collimated high-purity germanium detector (HPGe). Conventional Doppler broadening spectrometry (DBS) was performed to determine S, W and T parameters for our samples.

  4. Inner Radiation Belt Source of Helium and Heavy Hydrogen Nuclei Isotope

    Science.gov (United States)

    Galper, A. M.; Koldashov, S. V.; Leonov, A. A.; Mikhailov, V. V.

    Nuclear interactions between inner zone protons and atoms in the upper atmosphere provide the essential source of H and He isotopes nuclei in radiation belt. This paper reports specified calculations of these isotopes intensities from the various inner zone proton intensity models AP-8, CRRESPRO and SAMPEX/PET PSB97, the atmosphere drift-averaged composition and densities model MSIS-90, and cross sections for the interaction processes from the GNASH nuclear model code. To calculate drift-averaged densities and energy losses of secondaries the particles are traced in geomagnetic field according IGRF-95 model by numerical solution of motion equation. The calculations account for nuclear interactions kinematic along the whole trapped protons trajectories. The comparison with observational data from SAMPEX, CRRES, RESURS-04 and MITA satellites taken during different solar activity phases shows that the atmosphere is sufficient source for inner zone 4He, 3He, 2H and 3H for L-shell less than 1.3. The calculation model allows having the energy spectrum and angle distribution of light nuclear isotopes in inner radiation belt that can be used to evaluate SEU rates.

  5. THz and Sub-THz Capabilities of a Table-Top Radiation Source Driven by an RF Thermionic Electron Gun

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Alexei V.; Agustsson, R.; Boucher, S.; Campese, Tara; Chen, Y.C.; Hartzell, Josiah J.; Jocobson, B.T.; Murokh, A.; O' Shea, F.H.; Spranza, E.; Berg, W.; Borland, M.; Dooling, J. C.; Erwin, L.; Lindberg, R. R.; Pasky, S.J.; Sereno, N.; Sun, Y.; Zholents, A.

    2017-06-01

    Design features and experimental results are presented for a sub-mm wave source [1] based on APS RF thermionic electron gun. The setup includes compact alpha-magnet, quadrupoles, sub-mm-wave radiators, and THz optics. The sub-THz radiator is a planar, oversized structure with gratings. Source upgrade for generation frequencies above 1 THz is discussed. The THz radiator will use a short-period undulator having 1 T field amplitude, ~20 cm length, and integrated with a low-loss oversized waveguide. Both radiators are integrated with a miniature horn antenna and a small ~90°-degree in-vacuum bending magnet. The electron beamline is designed to operate different modes including conversion to a flat beam interacting efficiently with the radiator. The source can be used for cancer diagnostics, surface defectoscopy, and non-destructive testing. Sub-THz experiment demonstrated a good potential of a robust, table-top system for generation of a narrow bandwidth THz radiation. This setup can be considered as a prototype of a compact, laser-free, flexible source capable of generation of long trains of Sub-THz and THz pulses with repetition rates not available with laser-driven sources.

  6. Evaluation of blackbody radiation emitted by arbitrarily shaped bodies using the source model technique.

    Science.gov (United States)

    Sister, Ilya; Leviatan, Yehuda; Schächter, Levi

    2017-06-12

    Planck's famous blackbody radiation law was derived under the assumption that the dimensions of the radiating body are significantly larger than the radiated wavelengths. What is unique about Planck's formula is the fact that it is independent of the exact loss mechanism and the geometry. Therefore, for a long period of time, it was regarded as a fundamental property of all materials. Deviations from its predictions were attributed to imperfections and referred to as the emissivity of the specific body, a quantity which was always assumed to be smaller than unity. Recent studies showed that the emission spectrum is affected by the geometry of the body and in fact, in a limited frequency range, the emitted spectrum may exceed Planck's prediction provided the typical size of the body is of the same order of magnitude as the emitted wavelength. For the investigation of the blackbody radiation from an arbitrarily shaped body, we developed a code which incorporates the fluctuation-dissipation theorem (FDT) and the source model technique (SMT). The former determines the correlation between the quasi-microscopic current densities in the body and the latter is used to solve the electromagnetic problem numerically. In this study we present the essence of combining the two concepts. We verify the validity of our code by comparing its results obtained for the case of a sphere against analytic results and discuss how the accuracy of the solution is assessed in the general case. Finally, we illustrate several configurations in which the emitted spectrum exceeds Planck's prediction as well as cases in which the geometrical resonances of the body are revealed.

  7. Bayesian estimation of a source term of radiation release with approximately known nuclide ratios

    Science.gov (United States)

    Tichý, Ondřej; Šmídl, Václav; Hofman, Radek

    2016-04-01

    We are concerned with estimation of a source term in case of an accidental release from a known location, e.g. a power plant. Usually, the source term of an accidental release of radiation comprises of a mixture of nuclide. The gamma dose rate measurements do not provide a direct information on the source term composition. However, physical properties of respective nuclide (deposition properties, decay half-life) can be used when uncertain information on nuclide ratios is available, e.g. from known reactor inventory. The proposed method is based on linear inverse model where the observation vector y arise as a linear combination y = Mx of a source-receptor-sensitivity (SRS) matrix M and the source term x. The task is to estimate the unknown source term x. The problem is ill-conditioned and further regularization is needed to obtain a reasonable solution. In this contribution, we assume that nuclide ratios of the release is known with some degree of uncertainty. This knowledge is used to form the prior covariance matrix of the source term x. Due to uncertainty in the ratios the diagonal elements of the covariance matrix are considered to be unknown. Positivity of the source term estimate is guaranteed by using multivariate truncated Gaussian distribution. Following Bayesian approach, we estimate all parameters of the model from the data so that y, M, and known ratios are the only inputs of the method. Since the inference of the model is intractable, we follow the Variational Bayes method yielding an iterative algorithm for estimation of all model parameters. Performance of the method is studied on simulated 6 hour power plant release where 3 nuclide are released and 2 nuclide ratios are approximately known. The comparison with method with unknown nuclide ratios will be given to prove the usefulness of the proposed approach. This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases

  8. Separation of radiated sound field components from waves scattered by a source under non-anechoic conditions

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn

    2010-01-01

    A method of estimating the sound field radiated by a source under non-anechoic conditions has been examined. The method uses near field acoustic holography based on a combination of pressure and particle velocity measurements in a plane near the source for separating outgoing and ingoing wave...... components. The outgoing part of the sound field is composed of both radiated and scattered waves. The method compensates for the scattered components of the outgoing field on the basis of the boundary condition of the problem, exploiting the fact that the sound field is reconstructed very close...... to the source. Thus the radiated free-field component is estimated simultaneously with solving the inverse problem of reconstructing the sound field near the source. The method is particularly suited to cases in which the overall contribution of reflected sound in the measurement plane is significant....

  9. Radiation source reconstruction with known geometry and materials using the adjoint

    Energy Technology Data Exchange (ETDEWEB)

    Hykes, Joshua M.; Azmy, Yousry Y., E-mail: jmhykes@ncsu.edu, E-mail: yyazmy@ncsu.gov [Department of Nuclear Engineering, North Carolina State University, Raleigh, NC (United States)

    2011-07-01

    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)

  10. The Earth's Electron Radiation Belts Modeling: from the Source Population to Relativistic Energies

    Science.gov (United States)

    Aseev, N.; Shprits, Y. Y.; Kellerman, A. C.; Drozdov, A.; Zhu, H.

    2016-12-01

    The dynamics of the Earth's electron radiation belts is characterized by intricate interactions of different particle populations. During the main phase of a geomagnetic storm, electron source (tens keV) and seed (hundreds keV) populations are injected from the plasma sheet to the outer belt region. The source population transfers energy to electromagnetic waves, while the seed population can be accelerated locally by interaction with chorus waves. Electrons can also be lost by scattering into the loss cone due to wave-particle interaction and by magnetopause shadowing due to outward radial motion. In this work, we present results of simulations of the dynamics of electron fluxes in the inner magnetosphere from a few keV to relativistic energies of several MeV using the VERB-4D code. The code includes radial, energy and pitch angle diffusion, convection and adiabatic effects due to compression or expansion of the magnetic field. We extended the spatial outer boundary of the computational domain to 10-15 RE which allow us to study, how the source and seed population particles are convected from the plasma sheet, accelerated to relativistic energies and lost to the atmosphere or the magnetopause. The results of simulations reproduce Van Allen Probes, GOES and THEMIS observations, indicating that magnetospheric convection is the main driver of electron dynamics above the GEO, while radial diffusion and local diffusion are the most important processes in the outer belt region.

  11. Development of partially-coherent wavefront propagation simulation methods for 3rd and 4th generation synchrotron radiation sources

    Science.gov (United States)

    Chubar, Oleg; Berman, Lonny; Chu, Yong S.; Fluerasu, Andrei; Hulbert, Steve; Idir, Mourad; Kaznatcheev, Konstantine; Shapiro, David; Shen, Qun; Baltser, Jana

    2011-09-01

    Partially-coherent wavefront propagation calculations have proven to be feasible and very beneficial in the design of beamlines for 3rd and 4th generation Synchrotron Radiation (SR) sources. These types of calculations use the framework of classical electrodynamics for the description, on the same accuracy level, of the emission by relativistic electrons moving in magnetic fields of accelerators, and the propagation of the emitted radiation wavefronts through beamline optical elements. This enables accurate prediction of performance characteristics for beamlines exploiting high SR brightness and/or high spectral flux. Detailed analysis of radiation degree of coherence, offered by the partially-coherent wavefront propagation method, is of paramount importance for modern storage-ring based SR sources, which, thanks to extremely small sub-nanometer-level electron beam emittances, produce substantial portions of coherent flux in X-ray spectral range. We describe the general approach to partially-coherent SR wavefront propagation simulations and present examples of such simulations performed using "Synchrotron Radiation Workshop" (SRW) code for the parameters of hard X-ray undulator based beamlines at the National Synchrotron Light Source II (NSLS-II), Brookhaven National Laboratory. These examples illustrate general characteristics of partially-coherent undulator radiation beams in low-emittance SR sources, and demonstrate advantages of applying high-accuracy physical-optics simulations to the optimization and performance prediction of X-ray optical beamlines in these new sources.

  12. Spectrum shaping of accelerator-based neutron beams for BNCT

    CERN Document Server

    Montagnini, B; Esposito, J; Giusti, V; Mattioda, F; Varone, R

    2002-01-01

    We describe Monte Carlo simulations of three facilities for the production of epithermal neutrons for Boron Neutron Capture Therapy (BNCT) and examine general aspects and problems of designing the spectrum-shaping assemblies to be used with these neutron sources. The first facility is based on an accelerator-driven low-power subcritical reactor, operating as a neutron amplifier. The other two facilities have no amplifier and rely entirely on their primary sources, a D-T fusion reaction device and a conventional 2.5 MeV proton accelerator with a Li target, respectively.

  13. Measuring the radiative properties of astrophysical matter using the Z X-ray source

    Science.gov (United States)

    Bailey, James; ZAPP Team

    2017-06-01

    The Z Astrophysical Plasma Properties (ZAPP) collaboration is staging Z experiments that simultaneously investigate multiple topics in radiative properties of hot dense matter. The four astrophysics questions presently guiding this research are: 1) Why can’t we predict the location of the convection zone base in the Sun?; 2) How does radiation transport affect spectrum formation in accretion-powered objects?; 3) Why doesn’t spectral fitting provide the correct properties for White Dwarfs?; and 4) Why can’t we predict the heating and charge state distribution in photoionized plasmas? Recent progress using Z, the most energetic x-ray source on earth, to address these questions will be described. We emphasize the first two topics. Opacity models are an essential ingredient of stellar models and are highly sophisticated, but laboratory opacity tests have only now become possible at the conditions existing inside stars. Our opacity research emphasizes measuring iron at conditions relevant to the base of the solar convection zone, where the electron temperature and density are believed to be 190 eV and 9x1022 e/cc, respectively. The results exhibit large disagreements between iron opacity measurements and models and ongoing research is aimed at testing hypotheses for this discrepancy. The second project is motivated by the fact that emission lines from L-shell ions are not observed from iron in black hole accretion disks, but are observed from silicon in x-ray binaries. These disparate observations may be explained by differences in the radiation transport within the plasmas, but models for the spectral line formation and transport in photoionized plasmas have never been tested. We investigate photoionized silicon plasmas using absorption spectroscopy to infer the plasma conditions and emission spectroscopy to determine the dependence of spectral emission on plasma column density.++Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed

  14. Building an open-source simulation platform of acoustic radiation force-based breast elastography.

    Science.gov (United States)

    Wang, Yu; Peng, Bo; Jiang, Jingfeng

    2017-03-07

    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. In

  15. 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

  16. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Haris, K. [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India); Singh, Param Jeet [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Shastri, Aparna, E-mail: ashastri@barc.gov.in [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sunanda, K.; Babita, K.; Rao, S.V.N. Bhaskara [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Ahmad, Shabbir; Tauheed, A. [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India)

    2014-12-11

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 m off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu{sup 2+} phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O{sub 2}, N{sub 2}O and SO{sub 2} are carried out to evaluate the performance of the IP detection system. An FWHM of ∼0.5 Å is achieved for the Xe atomic line at 1469.6 Å. Reproducibility of spectra is found to be within the experimental resolution. Compared to the PMT scanning system, the IP shows several advantages in terms of sensitivity, recording time and S/N ratio, which are highlighted in the paper. This is the first report of incorporation of an IP detection system in a VUV beamline using synchrotron radiation. Commissioning of the new detection system is expected to greatly enhance the utilization of the HRVUV beamline as a number of spectroscopic experiments which require fast recording times combined with a good signal to noise ratio are now feasible. - Highlights: • Incorporation of an image plate detection system on HRVUV beamline at Indus-1. • Design and fabrication of mounting mechanisms, performance evaluation of new system. • Photoabsorption spectra of Xe, O{sub 2}, SO{sub 2} and N{sub 2}O recorded in the region 1150–2300 Å. • Sensitivity, wavelength coverage, reproducibility and resolution of IP demonstrated. • First report of IP detector for VUV photoabsorption using synchrotron radiation.

  17. 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.

  18. Evaluation of integrity of radiation sources of nuclear gauges; Avaliacao da integridade de fontes radioativas de medidores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Torohate, Wiclif Francisco

    2016-11-01

    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)

  19. Leaf surface wax is a source of plant methane formation under UV radiation and in the presence of oxygen

    DEFF Research Database (Denmark)

    Bruhn, Dan; Mikkelsen, Teis Nørgaard; Rolsted, M. M. M.

    2014-01-01

    The terrestrial vegetation is a source of UV radiation-induced aerobic methane (CH4) release to the atmosphere. Hitherto pectin, a plant structural component, has been considered as the most likely precursor for this CH4 release. However, most of the leaf pectin is situated below the surface wax...... layer, and UV transmittance of the cuticle differs among plant species. In some species, the cuticle effectively absorbs and/or reflects UV radiation. Thus, pectin may not necessarily contribute substantially to the UV radiation-induced CH4 emission measured at surface level in all species. Here, we...... investigated the potential of the leaf surface wax itself as a source of UV radiationinduced leaf aerobic CH4 formation. Isolated leaf surface wax emitted CH4 at substantial rates in response to UV radiation. This discovery has implications for how the phenomenon should be scaled to global levels. In relation...

  20. Improved nonlinear optimization in the storage ring of the modern synchrotron radiation light source

    Institute of Scientific and Technical Information of China (English)

    TIAN Shun-Qiang; LIU Gui-Min; HOU Jie; CHEN Guang-Ling; CHEN Sen-Yu

    2009-01-01

    In the storage ring of the third generation light sources,nonlinear optimization is an indispensable course in order to obtain ample dynamic acceptances and to reach high injection efficiency and long beam lifetime,especially in a low emittance lattice.An improved optimization algorithm based on the single resonance approach,which takes relative weight and initial Harmonic Sextupole Integral Strength (HSIS) as search variables,is discussed in this paper.Applications of the improved method in several test lattices are presented.Detailed analysis of the storage ring of the Shanghai Synchrotron Radiation Facility (SSRF) is particularly emphasized.Furthermore,cancellation of the driving terms is investigated to reveal the physical mechanism of the harmonic sextupole compensation.Sensitivity to the weight and the initial HSIS as well as dependence of the optimum solution on the convergent factor is analyzed.

  1. Vacuum system design of the third generation synchrotron radiation source PETRA III

    Energy Technology Data Exchange (ETDEWEB)

    Boespflug, R; Boster, J; Giesske, W; Keese, D; Koehler, R; Mildner, N; Nagorny, B; Naujoks, U; Remde, H; Schulz, E; Seidel, M; Tiessen, J; Wedekind, H P; Zapfe, K [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg (Germany)], E-mail: boris.nagorny@desy.de

    2008-03-01

    Within the next two years the 2.3 km long storage ring PETRA will be rebuild into one of the most brilliant x-ray sources worldwide (PETRA III). The large bending radius and the use of damping wigglers allow to achieve small beam emittances and extremely brilliant x-ray beams. In this paper we describe the design and the expected performance of the vacuum system for the storage ring. It consists of standard arc sections, an experimental octant which is equipped with undulators and several straight sections that include the damping wigglers. Because of the long length of the storage ring a cost effective solution had to be found. Besides the requirement to quickly provide acceptable residual gas pressures the technical challenges of the system include the provision of high thermal stability with respect to magnets and BPM's, and the design of thin walled insertion device chambers as well as high power synchrotron radiation absorbers.

  2. Investigation on the use of Americium Oxide for Space Power Sources: Radiation Damage Studies

    Directory of Open Access Journals (Sweden)

    Wiss T.

    2017-01-01

    Several candidate Americium compounds will be investigated for chemical stability at high temperature and for self-irradiation damage. New thermo-electric converter materials containing actinides will be assessed, and a robust encapsulation designed. Safety analyses will be performed including launch explosion and re-entry accidents. The research will conclude in a conceptual design of a prototype power source. In the first part of this study, americium dioxide will be considered from the point of view of its chemical durability and of its behavior against radiation damage and helium formation, two aspects to be carefully investigated due to the high alpha-activity of the americium. Transmission electron Microscopy (TEM and helium thermal desorption spectrometry (TDS experiments will be described and results on aged (more than 30 years AmO2 reported. Some comparison with 238PuO2 based RTG’s will be discussed.

  3. Progress Towards A Dedicated Synchrotron Radiation Source For Ultrafast X-Ray Science

    Science.gov (United States)

    Lidia, Steve

    2002-03-01

    We present progress towards the design of a femtosecond synchrotron radiation x-ray source based on a flat-beam rf gun and a recirculating superconducting linac that provides beam to an array of undulators and bend magnets. Optical pulse durations of <100 fs are obtained by a combination of electron pulse compression, transverse temporal correlation of the electrons, and x-ray pulse compression. After an introduction and initial scientific motivation, we cover the following aspects of the design: layout and lattice, ultra-fast x-ray pulse production, flat electron-beam production, the rf gun, rf systems, cryogenic systems, collective effects, photon production, and synchronization of x-ray and laser pulses. We conclude with a summary of issues and areas of development that remain to be addressed.

  4. Design of a new compact THz source based on Smith-Purcell radiation

    Institute of Scientific and Technical Information of China (English)

    DAI Dong-Dong; BEI Hua; DAI Zhi-Min

    2009-01-01

    In recent years,people are dedicated to the research work of finding compact THz sources with high emission power.Smith-Purcell radiation is qualified for the possibility of coherent enhancement due to the effect of FEL mechanism.The compact experiment device is expected to produce hundreds mW level THz ray.The electron beam with good quality is provided under the optimized design of the electron gun.Besides,the grating is designed as an oscillator without any external feedbacks.While the beam passes through the grating surface,the beam bunching will be strong and the second harmonics enhancement will be evident,as is seen from the simulation results.

  5. Initial feasibility study of a dedicated synchrotron radiation light source for ultrafast X-ray science

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, John N.; DeSantis, S.; Hartman, N.; Heimann, P.; LaFever, R.; Li, D.; Padmore, H.; Rimmer, R.; Robinson, K.; Schoenlein, R.; Tanabe, J.; Wang, S.; Zholents, A.; Kairan, D.

    2001-10-26

    We present an initial feasibility summary of a femtosecond synchrotron radiation x-ray source based on a flat-beam rf gun and a recirculating superconducting linac that provides beam to an array of undulators and bend magnets. Optical pulse durations of < 100 fs are obtained by a combination of electron pulse compression, transverse temporal correlation of the electrons, and x-ray pulse compression. After an introduction and initial scientific motivation, we cover the following aspects of the design: layout and lattice, ultra-fast x-ray pulse production, flat electron-beam production, the rf gun, rf systems, cryogenic systems, collective effects, photon production, and synchronization of x-ray and laser pulses. We conclude with a summary of issues and areas of development that remain to be addressed.

  6. Monte Carlo Simulations of Synchrotron Radiation and Vacuum Performance of the MAX IV Light Sources

    CERN Document Server

    Ady, M; Grabski, M

    2014-01-01

    In the 3 GeV ring of MAX IV light source in Lund, Sweden, the intense synchrotron radiation (SR) distributed along the ring generates important thermal and vacuum effects. By means of a Monte Carlo simulation package, which is currently developed at CERN, both thermal and vacuum effects are quantitatively analysed, in particular near the crotch absorbers and the surrounding NEG-coated vacuum chambers. Using SynRad+, the beam trajectory of the upstream bending magnet is calculated; SR photons are generated and traced through the geometry until their absorption. This allows an analysis of the incident power density on the absorber, and to calculate the photon induced outgassing. The results are imported to Molflow+, a Monte Carlo vacuum simulator that works in the molecular flow regime, and the pressure in the vacuum system and the saturation length of the NEG coating are determined using iterations.

  7. The Advanced Photon Source: A national synchrotron radiation research facility at Argonne National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The vision of the APS sprang from prospective users, whose unflagging support the project has enjoyed throughout the decade it has taken to make this facility a reality. Perhaps the most extraordinary aspect of synchrotron radiation research, is the extensive and diverse scientific makeup of the user community. From this primordial soup of scientists exchanging ideas and information, come the collaborative and interdisciplinary accomplishments that no individual alone could produce. So, unlike the solitary Roentgen, scientists are engaged in a collective and dynamic enterprise with the potential to see and understand the structures of the most complex materials that nature or man can produce--and which underlie virtually all modern technologies. This booklet provides scientists and laymen alike with a sense of both the extraordinary history of x-rays and the knowledge they have produced, as well as the potential for future discovery contained in the APS--a source a million million times brighter than the Roentgen tube.

  8. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    Science.gov (United States)

    Haris, K.; Singh, Param Jeet; Shastri, Aparna; Sunanda, K.; Babita, K.; Rao, S. V. N. Bhaskara; Ahmad, Shabbir; Tauheed, A.

    2014-12-01

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 m off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu2+ phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O2, N2O and SO2 are carried out to evaluate the performance of the IP detection system. An FWHM of ~0.5 Å is achieved for the Xe atomic line at 1469.6 Å. Reproducibility of spectra is found to be within the experimental resolution. Compared to the PMT scanning system, the IP shows several advantages in terms of sensitivity, recording time and S/N ratio, which are highlighted in the paper. This is the first report of incorporation of an IP detection system in a VUV beamline using synchrotron radiation. Commissioning of the new detection system is expected to greatly enhance the utilization of the HRVUV beamline as a number of spectroscopic experiments which require fast recording times combined with a good signal to noise ratio are now feasible.

  9. Cryogenic capability for equation-of-state measurements on the Sandia Z pulsed radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, D.L.; Johnston, R.R.; Asay, J.R.

    1998-02-01

    Experimental cryogenic capabilities are essential for the study of ICF high-gain target and weapons effects issues involving dynamic materials response at low temperatures. The authors are developing a general purpose cryogenic target system for precision radiation driven EOS and shock physics experiments at liquid helium temperatures on the Sandia Z pulsed radiation source. Cryogenic sample cooling in the range of 6--30 K is provided by a liquid helium cryostat and an active temperature control system. The cryogenic target assembly is capable of condensing liquid deuterium samples from the gas phase at about 20 K, as well as cooling solid samples such as beryllium and CH ablators for ICF. The target assembly will also include the capability to use various shock diagnostics, such as VISAR interferometry and fiber-optic-coupled shock breakout diagnostics. They are characterizing the thermal and optical performance of the system components in an off-line cryogenic test facility and have designed an interface to introduce the cryogenic transfer lines, gas lines, and sensor cables into the Z vacuum section. Survivability of high-value cryogenic components in the destructive post-implosion environment of Z is a major issue driving the design of this cryogenic target system.

  10. Development of synchrotron radiation as a high-intensity source for X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Huxley, H.E. [Brandeis Univ., Rosenstiel Center, Waltham, Massachusetts (United States); Holmes, K.C. [Max-Planck-Inst. fuer Medizinische Forschung, Heidelberg (Germany)

    1997-11-01

    Interest in the molecular mechanism of muscle contraction led to the search for an intense source of X-rays of 1-2 Aa wavelength so as to be able to examine the rich X-ray diffraction patterns given by muscles during contraction. This led to the first X-ray diffraction experiments using synchrotron radiation, carried out by Holmes, Rosenbaum and Witz at DESY, Hamburg, in September 1970. In the following years, the EMBL Outstation, to utilize synchrotron radiation for biological structure determination, was established at DESY and preliminary experiments on muscle were also carried out at NINA (Daresbury). The development of time-resolved techniques for muscle diffraction was first started in the MRC Molecular Biology Laboratory in Cambridge, using rotating-anode X-ray tubes, and was then greatly extended at the EMBL Outstation, Hamburg, using the storage ring DORIS. This was a very successful venture, and helped to drive the whole technology development and to interest other potential users in the technique. (au).

  11. Intense ion beam generation, plasma radiation source and plasma opening switch research

    Science.gov (United States)

    Hammer, D. A.; Coleman, M. D.; Qi, N.; Similon, P. L.; Sudan, R. N.

    1989-04-01

    This report describes research on intense ion beam diodes, plasma opening switches and dense z-pinch plasma radiators. Laser induced fluorescence spectroscopy has been used to map the electrostatic potential profile in a plasma-prefilled magnetically insulated ion diode. In a simple planar diode, the measured profile is inconsistent with the electrons being confined in a sheath near the cathode by the magnetic field. Rather, the profile implies the presence of electrons throughout the accelerating gap. A theoretical model of the penetration of current and magnetic field into a plasma, and of the current-driven effective collision frequency has been developed. The snowplow action of the rising magnetic field causes a steep rise in the plasma density at the leading edge. The subsequent multistreaming of the ions caused by ion reflection at the current layer could lead to ion heating through collective effects. The two-dimensional electron flow in the plasma cathode vacuum gap is also treated. Dense z-pinch plasma radiation source experiments have been initiated on the LION accelerator using gas puff and fine wire loads. The x-pinch was found to be a more effective way to generate soft x-rays than a single wire pinch or a gas puff implosion. Plasma opening switch experiments being initiated, and plasma anode ion diode development work being terminated are also briefly described.

  12. Photostimulated phosphor based image plate detection system for HRVUV beamline at Indus-1 synchrotron radiation source

    CERN Document Server

    Haris, K; Shastri, Aparna; K., Sunanda; K., Babita; Rao, S V N Bhaskara; Ahmad, Shabbir; Tauheed, A

    2014-01-01

    A high resolution vacuum ultraviolet (HRVUV) beamline based on a 6.65 meter off-plane Eagle spectrometer is in operation at the Indus-1 synchrotron radiation source, RRCAT, Indore, India. To facilitate position sensitive detection and fast spectral recording, a new BaFBr:Eu2+ phosphor based image plate (IP) detection system interchangeable with the existing photomultiplier (PMT) scanning system has been installed on this beamline. VUV photoabsorption studies on Xe, O2, N2O and SO2 are carried out to evaluate the performance of the IP detection system. An FWHM of ~ 0.5 {\\AA} is achieved for the Xe atomic line at 1469.6 {\\AA}. Reproducibility of spectra is found to be within the experimental resolution. Compared to the PMT scanning system, the IP shows several advantages in terms of sensitivity, recording time and S/N ratio, which are highlighted in the paper. This is the first report of incorporation of an IP detection system in a VUV beamline using synchrotron radiation. Commissioning of the new detection sys...

  13. Mortality among mound workers exposed to polonium-210 and other sources of radiation, 1944-1979.

    Science.gov (United States)

    Boice, John D; Cohen, Sarah S; Mumma, Michael T; Ellis, Elizabeth Dupree; Cragle, Donna L; Eckerman, Keith F; Wallace, Phillip W; Chadda, Bandana; Sonderman, Jennifer S; Wiggs, Laurie D; Richter, Bonnie S; Leggett, Richard W

    2014-02-01

    Polonium-210 is a naturally occurring radioactive element that decays by emitting an alpha particle. It is in the air we breathe and also a component of tobacco smoke. Polonium-210 is used as an anti-static device in printing presses and gained widespread notoriety in 2006 after the poisoning and subsequent death of a Russian citizen in London. More is known about the lethal effects of polonium-210 at high doses than about late effects from low doses. Cancer mortality was examined among 7,270 workers at the Mound nuclear facility near Dayton, OH where polonium-210 was used (1944-1972) in combination with beryllium as a source of neutrons for triggering nuclear weapons. Other exposures included external gamma radiation and to a lesser extent plutonium-238, tritium and neutrons. Vital status and cause of death was determined through 2009. Standardized mortality ratios (SMRs) were computed for comparisons with the general population. Lifetime occupational doses from all places of employment were sought and incorporated into the analysis. Over 200,000 urine samples were analyzed to estimate radiation doses to body organs from polonium and other internally deposited radionuclides. Cox proportional hazards models were used to evaluate dose-response relationships for specific organs and tissues. Vital status was determined for 98.7% of the workers of which 3,681 had died compared with 4,073.9 expected (SMR 0.90; 95% CI 0.88-0.93). The mean dose from external radiation was 26.1 mSv (maximum 939.1 mSv) and the mean lung dose from external and internal radiation combined was 100.1 mSv (maximum 17.5 Sv). Among the 4,977 radiation workers, all cancers taken together (SMR 0.86; 95% CI 0.79-0.93), lung cancer (SMR 0.85; 95% CI 0.74-0.98), and other types of cancer were not significantly elevated. Cox regression analysis revealed a significant positive dose-response trend for esophageal cancer [relative risk (RR) and 95% confidence interval at 100 mSv of 1.54 (1.15-2.07)] and a

  14. Radiative Transfer in a Translucent Cloud Illuminated by an Extended Background Source

    Science.gov (United States)

    Biganzoli, Davide; Potenza, Marco A. C.; Robberto, Massimo

    2017-05-01

    We discuss the radiative transfer theory for translucent clouds illuminated by an extended background source. First, we derive a rigorous solution based on the assumption that multiple scatterings produce an isotropic flux. Then we derive a more manageable analytic approximation showing that it nicely matches the results of the rigorous approach. To validate our model, we compare our predictions with accurate laboratory measurements for various types of well-characterized grains, including purely dielectric and strongly absorbing materials representative of astronomical icy and metallic grains, respectively, finding excellent agreement without the need to add free parameters. We use our model to explore the behavior of an astrophysical cloud illuminated by a diffuse source with dust grains having parameters typical of the classic ISM grains of Draine & Lee and protoplanetary disks, with an application to the dark silhouette disk 114-426 in Orion Nebula. We find that the scattering term modifies the transmitted radiation, both in terms of intensity (extinction) and shape (reddening) of the spectral distribution. In particular, for small optical thickness, our results show that scattering makes reddening almost negligible at visible wavelengths. Once the optical thickness increases enough and the probability of scattering events becomes close to or larger than 1, reddening becomes present but is appreciably modified with respect to the standard expression for line-of-sight absorption. Moreover, variations of the grain refractive index, in particular the amount of absorption, also play an important role in changing the shape of the spectral transmission curve, with dielectric grains showing the minimum amount of reddening.

  15. Gravitational Radiation from Post-Newtonian Sources and Inspiralling Compact Binaries

    Directory of Open Access Journals (Sweden)

    Luc Blanchet

    2014-02-01

    Full Text Available To be observed and analyzed by the network of gravitational wave detectors on ground (LIGO, VIRGO, etc. and by the future detectors in space (eLISA, etc., inspiralling compact binaries -- binary star systems composed of neutron stars and/or black holes in their late stage of evolution -- require high-accuracy templates predicted by general relativity theory. The gravitational waves emitted by these very relativistic systems can be accurately modelled using a high-order post-Newtonian gravitational wave generation formalism. In this article, we present the current state of the art on post-Newtonian methods as applied to the dynamics and gravitational radiation of general matter sources (including the radiation reaction back onto the source and inspiralling compact binaries. We describe the post-Newtonian equations of motion of compact binaries and the associated Lagrangian and Hamiltonian formalisms, paying attention to the self-field regularizations at work in the calculations. Several notions of innermost circular orbits are discussed. We estimate the accuracy of the post-Newtonian approximation and make a comparison with numerical computations of the gravitational self-force for compact binaries in the small mass ratio limit. The gravitational waveform and energy flux are obtained to high post-Newtonian order and the binary's orbital phase evolution is deduced from an energy balance argument. Some landmark results are given in the case of eccentric compact binaries -- moving on quasi-elliptical orbits with non-negligible eccentricity. The spins of the two black holes play an important role in the definition of the gravitational wave templates. We investigate their imprint on the equations of motion and gravitational wave phasing up to high post-Newtonian order (restricting to spin-orbit effects which are linear in spins, and analyze the post-Newtonian spin precession equations as well as the induced precession of the orbital plane.

  16. Open-Source Radiation Exposure Extraction Engine (RE3) with Patient-Specific Outlier Detection.

    Science.gov (United States)

    Weisenthal, Samuel J; Folio, Les; Kovacs, William; Seff, Ari; Derderian, Vana; Summers, Ronald M; Yao, Jianhua

    2016-08-01

    We present an open-source, picture archiving and communication system (PACS)-integrated radiation exposure extraction engine (RE3) that provides study-, series-, and slice-specific data for automated monitoring of computed tomography (CT) radiation exposure. RE3 was built using open-source components and seamlessly integrates with the PACS. RE3 calculations of dose length product (DLP) from the Digital imaging and communications in medicine (DICOM) headers showed high agreement (R (2) = 0.99) with the vendor dose pages. For study-specific outlier detection, RE3 constructs robust, automatically updating multivariable regression models to predict DLP in the context of patient gender and age, scan length, water-equivalent diameter (D w), and scanned body volume (SBV). As proof of concept, the model was trained on 811 CT chest, abdomen + pelvis (CAP) exams and 29 outliers were detected. The continuous variables used in the outlier detection model were scan length (R (2)  = 0.45), D w (R (2) = 0.70), SBV (R (2) = 0.80), and age (R (2) = 0.01). The categorical variables were gender (male average 1182.7 ± 26.3 and female 1047.1 ± 26.9 mGy cm) and pediatric status (pediatric average 710.7 ± 73.6 mGy cm and adult 1134.5 ± 19.3 mGy cm).

  17. Loss and source mechanisms of Jupiter's radiation belts near the inner boundary of trapping regions

    Science.gov (United States)

    Santos-Costa, Daniel; Bolton, Scott J.; Becker, Heidi N.; Clark, George; Kollmann, Peter; Paranicas, Chris; Mauk, Barry; Joergensen, John L.; Adriani, Alberto; Thorne, Richard M.; Bagenal, Fran; Janssen, Mike A.; Levin, Steve M.; Oyafuso, Fabiano A.; Williamson, Ross; Adumitroaie, Virgil; Ingersoll, Andrew P.; Kurth, Bill; Connerney, John E. P.

    2017-04-01

    We have merged a set of physics-based and empirical models to investigate the energy and spatial distributions of Jupiter's electron and proton populations in the inner and middle magnetospheric regions. Beyond the main source of plasma (> 5 Rj) where interchange instability is believed to drive the radial transport of charged particles, the method originally developed by Divine and Garrett [J. Geophys. Res., 88, 6889-6903, 1983] has been adapted. Closer to the planet where field fluctuations control the radial transport, a diffusion theory approach is used. Our results for the equatorial and mid-latitude regions are compared with Pioneer and Galileo Probe measurements. Data collected along Juno's polar orbit allow us to examine the features of Jupiter's radiation environment near the inner boundary of trapping regions. Significant discrepancies between Juno (JEDI keV energy particles and high energy radiation environment measurements made by Juno's SRU and ASC star cameras and the JIRAM infrared imager) and Galileo Probe data sets and models are observed close to the planet. Our simulations of Juno MWR observations of Jupiter's electron-belt emission confirm the limitation of our model to realistically depict the energy and spatial distributions of the ultra-energetic electrons. In this paper, we present our modeling approach, the data sets and resulting data-model comparisons for Juno's first science orbits. We describe our effort to improve our models of electron and proton belts. To gain a physical understanding of the dissimilarities with observations, we revisit the magnetic environment and the mechanisms of loss and source in our models.

  18. The statistical distributed source boundary point method to calculate the acoustic radiation from the random vibrating body

    Institute of Scientific and Technical Information of China (English)

    WANGXiufeng; CHENXinzhao; LIUZhao

    2003-01-01

    The statistical distributed source boundary point method (SDSBPM) put forward is applied to calculate the acoustic radiation from the random vibrating body. A detailed description of this method is presented. A test for the SDSBPM is carried out through the random vibrating sphere and the random vibrating cuboid. An experiment on the exterior acoustic radiation of a random vibrating simulation axial box of the lathe tool is performed in a semi-anechoic chamber.

  19. Method and system for determining depth distribution of radiation-emitting material located in a source medium and radiation detector system for use therein

    Energy Technology Data Exchange (ETDEWEB)

    Benke, Roland R. (Helotes, TX); Kearfott, Kimberlee J. (Ann Arbor, MI); McGregor, Douglas S. (Ann Arbor, MI)

    2003-03-04

    A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder positioned so that its central axis is perpendicular to the upper surface of the large area source when positioned thereon. The collimator allows the detector to angularly sample the emitted radiation over many ranges of polar angles. This is done by forming the collimator as a single adjustable collimator or a set of collimator pieces having various possible configurations when connected together. In any one configuration, the collimator allows the detector to detect only the radiation emitted from a selected range of polar angles measured from the detector axis. Adjustment of the collimator or the detector therein enables the detector to detect radiation emitted from a different range of polar angles. The system further includes a signal processor for processing the signals from the detector wherein signals obtained from different ranges of polar angles are processed together to obtain a reconstruction of the radiation-emitting material as a function of depth, assuming, but not limited to, a spatially-uniform depth distribution of the material within each layer. The detector system includes detectors having

  20. Model thermal response to minor radiative energy sources and sinks in the middle atmosphere

    Science.gov (United States)

    Fomichev, V. I.; Fu, C.; de Grandpré, J.; Beagley, S. R.; Ogibalov, V. P.; McConnell, J. C.

    2004-10-01

    This paper presents the thermal response of the Canadian middle atmosphere model (CMAM) to minor radiative energy sources and sinks. These include chemical heating, infrared (IR) H2O cooling, sphericity effect in solar heating, and solar heating in the near-IR CO2 bands. All of these energy sources/sinks can be considered as minor ones either in terms of their magnitude or in terms of the limited height region where they are of importance or both. To examine the thermal response of the middle atmosphere, a version of the CMAM with an interactive gas phase chemistry scheme has been used in a series of multiyear experiments for conditions of perpetual July. Each of the analyzed mechanisms may provide a noticeable contribution into the model energy balance that results in a statistically significant model response. Various forcing terms due to minor energy sources/sinks have different spatial and temporal distributions. Their magnitudes vary from tenths K d-1 for the sphericity effect up to ˜10 K d-1 for chemical heating that provides corresponding thermal responses of a few to about 20 K in the middle atmosphere. The model thermal response depends on the magnitude of the applied forcing but is not always local and can be spread beyond the regions where the forcing terms are initially applied. On a globally averaged basis the local strength of the model response is nearly proportional to the magnitude of the small forcing terms but shows nonlinearity when forcing due to chemical heating exceeds ˜1 K d-1 in the mesosphere. Accounting for the combined effects of the minor energy sources and sinks leads to a better agreement between the model temperature field and observations.

  1. Imaging of primary and secondary radiation-Modelling and experimental results of a radioactive source and a water phantom

    Science.gov (United States)

    Gamage, K. A. A.; Taylor, G. C.; Joyce, M. J.

    2014-11-01

    In this paper the contribution of primary and secondary radiation from a water phantom to a pinhole volume, as a result of three neutron sources (Cf, AmBe and 5 MeV mono-energetic) and two gamma sources (Cs and Co), is separately estimated using the PTRAC particle tracking option available in MCNP. Also in this paper imaging of the mixed radiation field produced by a Van de Graaf accelerator (when a water phantom is present) is described. In the model, a spherical tally volume, 2 cm in diameter, was placed equidistantly from a radioactive source and 30×30×15 cm3 water phantom. Monte Carlo simulations have been carried out to investigate the level of primary and secondary radiation contributing to the pinhole volume directly from the source and from interactions in the phantom respectively. The spatial distribution of counts clearly discriminated the source and the phantom. The results have shown that the percentage of neutrons reflected from the phantom with energies above 1 MeV increases with mean energy of the source. This method has significant potential to characterise secondary radiation in proton therapy, where it would help to verify the location and the energy delivered during the treatment.

  2. A robust hypothesis test for the sensitive detection of constant speed radiation moving sources

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan, E-mail: jonathan.dumazert@cea.fr [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France); Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim; Moline, Yoann; Sannié, Guillaume; Gameiro, Jordan; Normand, Stéphane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France); Méchin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 14050 Caen (France)

    2015-09-21

    Radiation Portal Monitors are deployed in linear networks to detect radiological material in motion. As a complement to single and multichannel detection algorithms, inefficient under too low signal-to-noise ratios, temporal correlation algorithms have been introduced. Test hypothesis methods based on empirically estimated mean and variance of the signals delivered by the different channels have shown significant gain in terms of a tradeoff between detection sensitivity and false alarm probability. This paper discloses the concept of a new hypothesis test for temporal correlation detection methods, taking advantage of the Poisson nature of the registered counting signals, and establishes a benchmark between this test and its empirical counterpart. The simulation study validates that in the four relevant configurations of a pedestrian source carrier under respectively high and low count rate radioactive backgrounds, and a vehicle source carrier under the same respectively high and low count rate radioactive backgrounds, the newly introduced hypothesis test ensures a significantly improved compromise between sensitivity and false alarm. It also guarantees that the optimal coverage factor for this compromise remains stable regardless of signal-to-noise ratio variations between 2 and 0.8, therefore allowing the final user to parametrize the test with the sole prior knowledge of background amplitude.

  3. Hypothesis tests for the detection of constant speed radiation moving sources

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan; Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim; Sannie, Guillaume; Gameiro, Jordan; Normand, Stephane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 99 Gif-sur-Yvette, (France); Mechin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 4050 Caen, (France)

    2015-07-01

    Radiation Portal Monitors are deployed in linear network to detect radiological material in motion. As a complement to single and multichannel detection algorithms, inefficient under too low signal to noise ratios, temporal correlation algorithms have been introduced. Test hypothesis methods based on empirically estimated mean and variance of the signals delivered by the different channels have shown significant gain in terms of a tradeoff between detection sensitivity and false alarm probability. This paper discloses the concept of a new hypothesis test for temporal correlation detection methods, taking advantage of the Poisson nature of the registered counting signals, and establishes a benchmark between this test and its empirical counterpart. The simulation study validates that in the four relevant configurations of a pedestrian source carrier under respectively high and low count rate radioactive background, and a vehicle source carrier under the same respectively high and low count rate radioactive background, the newly introduced hypothesis test ensures a significantly improved compromise between sensitivity and false alarm, while guaranteeing the stability of its optimization parameter regardless of signal to noise ratio variations between 2 to 0.8. (authors)

  4. Design and Experimental Demonstration of Cherenkov Radiation Source Based on Metallic Photonic Crystal Slow Wave Structure

    Science.gov (United States)

    Fu, Tao; Yang, Zi-Qiang; Ouyang, Zheng-Biao

    2016-11-01

    This paper presents a kind of Cherenkov radiation source based on metallic photonic crystal (MPC) slow-wave structure (SWS) cavity. The Cherenkov source designed by linear theory works at 34.7 GHz when the cathode voltage is 550 kV. The three-dimensional particle-in-cell (PIC) simulation of the SWS shows the operating frequency of 35.56 GHz with a single TM01 mode is basically consistent with the theoretically one under the same parameters. An experiment was implemented to testify the results of theory and PIC simulation. The experimental system includes a cathode emitting unit, the SWS, a magnetic system, an output antenna, and detectors. Experimental results show that the operating frequency through detecting the retarded time of wave propagation in waveguides is around 35.5 GHz with a single TM01 mode and an output power reaching 54 MW. It indicates that the MPC structure can reduce mode competition. The purpose of the paper is to show in theory and in preliminary experiment that a SWS with PBG can produce microwaves in TM01 mode. But it still provides a good experimental and theoretical foundation for designing high-power microwave devices.

  5. Tailoring high-temperature radiation and the resurrection of the incandescent source.

    Science.gov (United States)

    Ilic, Ognjen; Bermel, Peter; Chen, Gang; Joannopoulos, John D; Celanovic, Ivan; Soljačić, Marin

    2016-04-01

    In solar cells, the mismatch between the Sun's emission spectrum and the cells' absorption profile limits the efficiency of such devices, while in incandescent light bulbs, most of the energy is lost as heat. One way to avoid the waste of a large fraction of the radiation emitted from hot objects is to tailor the thermal emission spectrum according to the desired application. This strategy has been successfully applied to photonic-crystal emitters at moderate temperatures, but is exceedingly difficult for hot emitters (>1,000 K). Here, we show that a plain incandescent tungsten filament (3,000 K) surrounded by a cold-side nanophotonic interference system optimized to reflect infrared light and transmit visible light for a wide range of angles could become a light source that reaches luminous efficiencies (∼40%) surpassing existing lighting technologies, and nearing a limit for lighting applications. We experimentally demonstrate a proof-of-principle incandescent emitter with efficiency approaching that of commercial fluorescent or light-emitting diode bulbs, but with exceptional reproduction of colours and scalable power. The ability to tailor the emission spectrum of high-temperature sources may find applications in thermophotovoltaic energy conversion and lighting.

  6. Design of x-ray diagnostic beam line for a synchrotron radiation source and measurement results

    Science.gov (United States)

    Garg, Akash Deep; Karnewar, A. K.; Ojha, A.; Shrivastava, B. B.; Holikatti, A. C.; Puntambekar, T. A.; Navathe, C. P.

    2014-08-01

    Indus-2 is a 2.5 GeV synchrotron radiation source (SRS) operational at the Raja Ramanna Centre for Advanced Technology (RRCAT) in India. We have designed, developed and commissioned x-ray diagnostic beam line (X-DBL) at the Indus-2. It is based on pinhole array imaging (8-18 keV). We have derived new equations for online measurements of source position and emission angle with pinhole array optics. Measured values are compared with the measurements at an independent x-ray beam position monitor (staggered pair blade monitor) installed in the X-DBL. The measured values are close to the theoretical expected values within ±12 μm (or ±1.5 μrad) for sufficiently wide range of the beam movements. So, beside the beam size and the beam emittance, online information for the vertical position and angle is also used in the orbit steering. In this paper, the various design considerations of the X-DBL and online measurement results are presented.

  7. HELIOS-K: An Ultrafast, Open-source Opacity Calculator for Radiative Transfer

    CERN Document Server

    Grimm, Simon L

    2015-01-01

    We present an ultrafast opacity calculator for application to exoplanetary atmospheres, which we name HELIOS-K. It takes a line list as an input, computes the shape of each spectral line (e.g., a Voigt profile) and provides an option for grouping an enormous number of lines into a manageable number of bins. We implement a combination of Algorithm 916 and Gauss-Hermite quadrature to compute the Voigt profile, write the code in CUDA and optimise the computation for graphics processing units (GPUs). We use the k-distribution method to reduce $\\sim 10^5$ to $10^8$ lines to $\\sim 10$ to $10^4$ wavenumber bins, which may then be used for radiative transfer, atmospheric retrieval and general circulation models. We demonstrate that the resampling of the k-distribution function, within each bin, is an insignificant source of error across a broad range of wavenumbers and column masses. By contrast, the choice of line-wing cutoff for the Voigt profile is a significant source of error and affects the value of the compute...

  8. Tailoring high-temperature radiation and the resurrection of the incandescent source

    Science.gov (United States)

    Ilic, Ognjen; Bermel, Peter; Chen, Gang; Joannopoulos, John D.; Celanovic, Ivan; Soljačić, Marin

    2016-04-01

    In solar cells, the mismatch between the Sun's emission spectrum and the cells’ absorption profile limits the efficiency of such devices, while in incandescent light bulbs, most of the energy is lost as heat. One way to avoid the waste of a large fraction of the radiation emitted from hot objects is to tailor the thermal emission spectrum according to the desired application. This strategy has been successfully applied to photonic-crystal emitters at moderate temperatures, but is exceedingly difficult for hot emitters (>1,000 K). Here, we show that a plain incandescent tungsten filament (3,000 K) surrounded by a cold-side nanophotonic interference system optimized to reflect infrared light and transmit visible light for a wide range of angles could become a light source that reaches luminous efficiencies (∼40%) surpassing existing lighting technologies, and nearing a limit for lighting applications. We experimentally demonstrate a proof-of-principle incandescent emitter with efficiency approaching that of commercial fluorescent or light-emitting diode bulbs, but with exceptional reproduction of colours and scalable power. The ability to tailor the emission spectrum of high-temperature sources may find applications in thermophotovoltaic energy conversion and lighting.

  9. Locally Targeted Delivery of a Micron-Size Radiation Therapy Source Using Temperature-Sensitive Hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yusung, E-mail: yusung-kim@uiowa.edu [Department of Radiation Oncology, The University of Iowa, Iowa City, Iowa (United States); Seol, Dong Rim [Department of Orthopaedic Surgery, The University of Iowa, Iowa City, Iowa (United States); Mohapatra, Sucheta [Department of Biomedical Engineering, The University of Iowa, Iowa City, Iowa (United States); Sunderland, John J. [Department of Radiology, The University of Iowa, Iowa City, Iowa (United States); Schultz, Michael K. [Department of Radiation Oncology, The University of Iowa, Iowa City, Iowa (United States); Department of Radiology, The University of Iowa, Iowa City, Iowa (United States); Domann, Frederick E. [Department of Radiation Oncology, The University of Iowa, Iowa City, Iowa (United States); Department of Surgery, The University of Iowa, Iowa City, Iowa (United States); Lim, Tae-Hong [Department of Biomedical Engineering, The University of Iowa, Iowa City, Iowa (United States)

    2014-04-01

    Purpose: To propose a novel radiation therapy (RT) delivery modality: locally targeted delivery of micron-size RT sources by using temperature-sensitive hydrogel (RT-GEL) as an injectable vehicle. Methods and Materials: Hydrogel is a water-like liquid at room temperature but gels at body temperature. Two US Food and Drug Administration-approved polymers were synthesized. Indium-111 (In-111) was used as the radioactive RT-GEL source. The release characteristics of In-111 from polymerized RT-GEL were evaluated. The injectability and efficacy of RT-GEL delivery to human breast tumor were tested using animal models with control datasets of RT-saline injection. As proof-of-concept studies, a total of 6 nude mice were tested by injecting 4 million tumor cells into their upper backs after a week of acclimatization. Three mice were injected with RT-GEL and 3 with RT-saline. Single-photon emission computed tomography (SPECT) and CT scans were performed on each mouse at 0, 24, and 48 h after injection. The efficacy of RT-GEL was determined by comparison with that of the control datasets by measuring kidney In-111 accumulation (mean nCi/cc), representing the distant diffusion of In-111. Results: RT-GEL was successfully injected into the tumor by using a 30-gauge needle. No difficulties due to polymerization of hydrogel during injection and intratumoral pressure were observed during RT-GEL injection. No back flow occurred for either RT-GEL or RT-saline. The residual tumor activities of In-111 were 49% at 24 h (44% at 48 h, respectively) for RT-GEL and 29% (22%, respectively) for RT-saline. Fused SPECT-CT images of RT-saline showed considerable kidney accumulation of In-111 (2886%, 261%, and 262% of RT-GEL at 0, 24, and 48 h, respectively). Conclusions: RT-GEL was successfully injected and showed much higher residual tumor activity: 170% (200%, respectively), than that of RT-saline at 24 h (48 h, respectively) after injection with a minimal accumulation of In-111 to the

  10. LIGHT SOURCE: Conceptual design of Hefei advanced light source

    Science.gov (United States)

    Li, Wei-Min; Wang, Lin; Feng, Guang-Yao; Zhang, Shan-Cai; Wu, Cong-Feng; Xu, Hong-Liang; Liu, Zu-Ping

    2009-06-01

    The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, on-momentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm · rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world.

  11. Dynamical analysis of an accelerator-based fluid-fueled subcritical radioactive waste burning system

    Science.gov (United States)

    Woosley, Michael Louis, Jr.

    The recent revival of interest in accelerator-driven subcritical fluid-fueled systems is documented. Several important applications of these systems are mentioned. In particular, new applications have focused on the destruction of high-level radioactive waste. Systems can be designed to quickly destroy the actinides and long-lived fission products from light water reactor fuel, weapons plutonium, and other high-level defense wastes. The proposed development of these systems is used to motivate the need for the development of dynamic analysis methods for their nuclear kinetics. A physical description of the Los Alamos Accelerator-Based Conversion (ABC) concept is provided. This system is used as the basis for the kinetics study in this research. The current approach to the dynamic simulation of an accelerator-driven subcritical fluid-fueled system includes three elements: A discrete ordinates model is used to calculate the flux distribution for the source-driven system; A nodal convection model is used to calculate time-dependent isotope and temperature distributions which impact reactivity; A nodal importance weighting model is used to calculate the reactivity impact of temperature and isotope distributions and to feed this information back to the time-dependent nodal convection model. Specific transients which have been analyzed with the current modeling system are discussed. These transients include loss-of-flow and loss-of-cooling accidents, xenon and samarium transients, and cold-plug and overfueling events. The results of various transients have uncovered unpredictable behavior, unresolved design issues, and the need for active control. Modest initiating events can cause significant swings in system temperature and power. The circulation of the fluid fuel can lead to oscillations on the relatively short scale of the loop circulation time. The system responds quickly to reactivity changes because the large neutron source overwhelms the damping effect of delayed

  12. Lab-scale EUV nano-imaging employing a gas-puff-target source: image quality versus plasma radiation characteristics

    Science.gov (United States)

    Wachulak, Przemyslaw; Bartnik, Andrzej; Fiedorowicz, Henryk

    2012-01-01

    In this chapter we report a desk-top microscopy reaching 50nm spatial resolution in very compact setup using a gas-puff laser plasma EUV source. We present the study of source bandwidth influence on the extreme ultraviolet (EUV) microscope spatial resolution. EUV images of object obtained by illumination with variable bandwidth EUV radiation were compared in terms of knife-edge spatial resolution to study the wide bandwidth parasitic influence on spatial resolution in the EUV microscopy.

  13. Astrophysical ionizing radiation and Earth: a brief review and census of intermittent intense sources.

    Science.gov (United States)

    Melott, Adrian L; Thomas, Brian C

    2011-05-01

    Cosmic radiation backgrounds are a constraint on life, and their distribution will affect the Galactic Habitable Zone. Life on Earth has developed in the context of these backgrounds, and characterizing event rates will elaborate the important influences. This in turn can be a base for comparison with other potential life-bearing planets. In this review, we estimate the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities, ranging from gamma-ray bursts at cosmological distances to the Sun itself. Many of these present potential hazards to the biosphere; on timescales long compared with human history, the probability of an event intense enough to disrupt life on the land surface or in the oceans becomes large. Both photons (e.g., X-rays) and high-energy protons and other nuclei (often called "cosmic rays") constitute hazards. For either species, one of the mechanisms that comes into play even at moderate intensities is the ionization of Earth's atmosphere, which leads through chemical changes (specifically, depletion of stratospheric ozone) to increased ultraviolet B flux from the Sun reaching the surface. UVB is extremely hazardous to most life due to its strong absorption by the genetic material DNA and subsequent breaking of chemical bonds. This often leads to mutation or cell death. It is easily lethal to the microorganisms that lie at the base of the food chain in the ocean. We enumerate the known sources of radiation and characterize their intensities at Earth and rates or upper limits on these quantities. When possible, we estimate a "lethal interval," our best estimate of how often a major extinction-level event is probable given the current state of knowledge; we base these estimates on computed or expected depletion of stratospheric ozone. In general, moderate-level events are dominated by the Sun, but the far more severe infrequent events are probably dominated by gamma-ray bursts and supernovae. We note

  14. Radiologic and nuclear medicine studies in the United States and worldwide: frequency, radiation dose, and comparison with other radiation sources--1950-2007.

    Science.gov (United States)

    Mettler, Fred A; Bhargavan, Mythreyi; Faulkner, Keith; Gilley, Debbie B; Gray, Joel E; Ibbott, Geoffrey S; Lipoti, Jill A; Mahesh, Mahadevappa; McCrohan, John L; Stabin, Michael G; Thomadsen, Bruce R; Yoshizumi, Terry T

    2009-11-01

    The U.S. National Council on Radiation Protection and Measurements and United Nations Scientific Committee on Effects of Atomic Radiation each conducted respective assessments of all radiation sources in the United States and worldwide. The goal of this article is to summarize and combine the results of these two publicly available surveys and to compare the results with historical information. In the United States in 2006, about 377 million diagnostic and interventional radiologic examinations and 18 million nuclear medicine examinations were performed. The United States accounts for about 12% of radiologic procedures and about one-half of nuclear medicine procedures performed worldwide. In the United States, the frequency of diagnostic radiologic examinations has increased almost 10-fold (1950-2006). The U.S. per-capita annual effective dose from medical procedures has increased about sixfold (0.5 mSv [1980] to 3.0 mSv [2006]). Worldwide estimates for 2000-2007 indicate that 3.6 billion medical procedures with ionizing radiation (3.1 billion diagnostic radiologic, 0.5 billion dental, and 37 million nuclear medicine examinations) are performed annually. Worldwide, the average annual per-capita effective dose from medicine (about 0.6 mSv of the total 3.0 mSv received from all sources) has approximately doubled in the past 10-15 years.

  15. John Adams Lecture | Accelerator-Based Neutrino Physics: Past, Present and Future by Kenneth Long | 8 December

    CERN Multimedia

    2014-01-01

    John Adams Lecture: Accelerator-Based Neutrino Physics: Past, Present and Future by Dr. Kenneth Long (Imperial College London & STFC).   Monday, 8 December 2014 from 2 p.m. to 4 p.m. at CERN ( 503-1-001 - Council Chamber ) Abstract: The study of the neutrino is the study of physics beyond the Standard Model. We now know that the neutrinos have mass and that neutrino mixing occurs causing neutrino flavour to oscillate as neutrinos propagate through space and time. Further, some measurements can be interpreted as hints for new particles known as sterile neutrinos. The measured values of the mixing parameters make it possible that the matter-antimatter (CP) symmetry may be violated through the mixing process. The consequences of observing CP-invariance violation in neutrinos would be profound. To discover CP-invariance violation will require measurements of exquisite precision. Accelerator-based neutrino sources are central to the future programme and advances in technique are required ...

  16. The space experiment CERASP: Definition of a space-suited radiation source and growth conditions for human cells

    Science.gov (United States)

    Hellweg, Christine E.; Baumstark-Khan, Christa; Spitta, Luis; Thelen, Melanie; Arenz, Andrea; Franz, Markus; Schulze-Varnholt, Dirk; Berger, Thomas; Reitz, Günther

    The combined action of ionizing radiation and microgravity will continue to influence future space missions, with special risks for astronauts on the Moon surface or for long duration missions to Mars. It has been estimated that on a 3-year mission to Mars about 3% of the bodies' cell nuclei would have been hit by one iron ion with the consequence that nuclear DNA will be heavily damaged. There is increasing evidence that basic cellular functions are sensitive not only to radiation but also to microgravity. DNA repair studies in space on bacteria, yeast cells and human fibroblasts, which were irradiated before, flight, gave contradictory results: from inhibition of repair by microgravity to enhancement, whereas others did not detect any influence of microgravity on repair. The space experiment CERASP (CEllular Responses to RAdiation in SPace) to be performed at the International Space Station (ISS) is aimed to supply basic information on the cellular response in microgravity to radiation applied during flight. It makes use of a recombinant human cell line as reporter for cellular signal transduction modulation by genotoxic environmental conditions. The main biological endpoints under investigation will be gene activation based on enhanced green fluorescent protein (EGFP, originally isolated from the bioluminescent jellyfish Aequorea victoria) expression controlled by a DNA damage-dependent promoter element which reflects the activity of the nuclear factor kappa B (NF- κB) pathway. The NF- κB family of proteins plays a major role in the inflammatory and immune response, cell proliferation and differentiation, anti-apoptosis and tumorgenesis. For radiation exposure during space flight a radiation source has been constructed as damage accumulation by cosmic radiation will certainly be insufficient for analysis. The space experiment specific hardware consists of a specially designed radiation source made up of the β-emitter promethium-147, combined with a

  17. Modelling single shot damage thresholds of multilayer optics for high-intensity short-wavelength radiation sources.

    Science.gov (United States)

    Loch, R A; Sobierajski, R; Louis, E; Bosgra, J; Bijkerk, F

    2012-12-17

    The single shot damage thresholds of multilayer optics for high-intensity short-wavelength radiation sources are theoretically investigated, using a model developed on the basis of experimental data obtained at the FLASH and LCLS free electron lasers. We compare the radiation hardness of commonly used multilayer optics and propose new material combinations selected for a high damage threshold. Our study demonstrates that the damage thresholds of multilayer optics can vary over a large range of incidence fluences and can be as high as several hundreds of mJ/cm(2). This strongly suggests that multilayer mirrors are serious candidates for damage resistant optics. Especially, multilayer optics based on Li(2)O spacers are very promising for use in current and future short-wavelength radiation sources.

  18. Combined radiative and natural or forced convective heat transfer between parallel vertical plates with two-dimensional discrete heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, T.W.

    1988-01-01

    This study numerically analyzes combined radiative and natural or forced convective heat transfer between vertical parallel plates with two-dimensional discrete heat sources. The numerical method was verified by comparing its results with other published experimental data and the agreement was excellent. It is shown that radiative heat transfer is a significant and useful mode of heat transfer in combination with both natural and forced convection in this situation and cannot be neglected. Radiative heat transfer accounted for 50-60% or more of the total heat transfer in some cases, and usually approximately 30-35% on the top of a discrete heat source. This fact can be used to advantage in the thermal design of electronic circuit boards.

  19. Radon adsorbed in activated charcoal—a simple and safe radiation source for teaching practical radioactivity in schools and colleges

    Science.gov (United States)

    Al-Azmi, Darwish; Mustapha, Amidu O.; Karunakara, N.

    2012-07-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, a ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 g of activated charcoal inside metallic canisters. Gamma radiation was subsequently emitted from the canisters, following the radioactive decay of radon and its progenies. The intensities of the emitted gamma-rays were measured at suitable intervals using a NaI gamma-ray detector. The counts obtained were analysed and used to demonstrate the radioactive decay law and determine the half-life of radon. In addition to learning the basic properties of radioactivity the students also get practical experience about the existence of natural sources of radiation in the environment.

  20. Quantifying sources, transport, deposition, and radiative forcing of black carbon over the Himalayas and Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rudong; Wang, Hailong; Qian, Yun; Rasch, Philip J.; Easter, Richard C.; Ma, Po-Lun; Singh, Balwinder; Huang, Jianping; Fu, Qiang

    2015-01-01

    Black carbon (BC)particles over the Himalayas and Tibetan Plateau (HTP), both airborne and those deposited on snow, have been shown to affect snowmelt and glacier retreat. Since BC over the HTP may originate from a variety of geographical regions and emission sectors, it is essential to quantify the source-receptor relationships of BC in order to understand the contributions of natural and anthropogenic emissions and provide guidance for potential mitigation actions. In this study, we use the Community Atmosphere Model version 5 (CAM5) with a newly developed source tagging technique, nudged towards the MERRA meteorological reanalysis, to characterize the fate of BC particles emitted from various geographical regions and sectors. Evaluated against observations over the HTP and surrounding regions, the model simulation shows a good agreement in the seasonal variation of the near-surface airborne BC concentrations, providing confidence to use this modeling framework for characterizing BC source- receptor relationships. Our analysis shows that the relative contributions from different geographical regions and source sectors depend on seasons and the locations in the HTP. The largest contribution to annual mean BC burden and surface deposition in the entire HTP region is from biofuel and biomass (BB) emissions in South Asia, followed by fossil fuel (FF) emissions from South Asia, then FF from East Asia. The same roles hold for all the seasonal means except for the summer when East Asia FF becomes more important. For finer receptor regions of interest, South Asia BB and FF have the largest impact on BC in Himalayas and Central Tibetan Plateau, while East Asia FF and BB contribute the most to Northeast Plateau in all seasons and Southeast Plateau in the summer. Central Asia and Middle East FF emissions have relatively more important contributions to BC reaching Northwest Plateau, especially in the summer. Although the HTP local emissions only contribute about 10% of BC in

  1. Radon Adsorbed in Activated Charcoal--A Simple and Safe Radiation Source for Teaching Practical Radioactivity in Schools and Colleges

    Science.gov (United States)

    Al-Azmi, Darwish; Mustapha, Amidu O.; Karunakara, N.

    2012-01-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, a ubiquitous inert gas, and the adsorptive property of activated charcoal.…

  2. 76 FR 82077 - Food Ingredients and Sources of Radiation Listed or Approved for Use in the Production of Meat...

    Science.gov (United States)

    2011-12-30

    ... and Sources of Radiation Listed or Approved for Use in the Production of Meat and Poultry Products... listed or approved for use in the production of meat and poultry products. DATES: December 30, 2011... Meat and Poultry Products'' (64 FR 72168). Among other things, this final rule consolidated various...

  3. 77 FR 26706 - Food Ingredients and Sources of Radiation Listed and Approved for Use in the Production of Meat...

    Science.gov (United States)

    2012-05-07

    ... and Sources of Radiation Listed and Approved for Use in the Production of Meat and Poultry Products... the list of substances that the regulations prohibit for use in meat or poultry products. Under this proposal, new uses of these substances in meat or poultry products would continue to be approved by the...

  4. Optical Cherenkov radiation by cascaded nonlinear interaction: an efficient source of few-cycle near- to mid-IR pulses

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Zhou, Binbin

    2011-01-01

    Through cascaded second-harmonic generation, few-cycle solitons can form that resonantly emit strongly red-shifted optical Cherenkov radiation. Numerical simulations show that such dispersive waves can be an efficient source of near- to mid-IR few-cycle broadband pulses....

  5. Radon Adsorbed in Activated Charcoal--A Simple and Safe Radiation Source for Teaching Practical Radioactivity in Schools and Colleges

    Science.gov (United States)

    Al-Azmi, Darwish; Mustapha, Amidu O.; Karunakara, N.

    2012-01-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, a ubiquitous inert gas, and the adsorptive property of activated charcoal.…

  6. 3D position of radiation sources using an automated gamma camera and ML algorithm with energy-dependent response functions

    Science.gov (United States)

    Lee, Wonho; Wehe, David

    2004-09-01

    Portable γ-ray imaging systems operating from 100keV to 3MeV are used in nuclear medicine, astrophysics and industrial applications. 2D images of γ-rays are common in many fields using radiation-detection systems (Appl. Opt. 17 (3) (1978) 337; IEEE Trans. Nucl. Sci. Ns- 31 (1984) 771; IEEE Trans. Nucl. Sci. NS- 44 (3) (1997) 911). In this work, the 3D position of a radiation source is determined by a portable gamma-ray imaging system. 2D gamma-ray images were obtained from different positions of the gamma camera and the third dimension, the distance between the detector and the radiation source, was calculated using triangulation. The imaging system consists of a 4×4 array of CsI(Tl) detectors coupled to photodiode detectors that are mounted on an automated table which can precisely position the angular axis of the camera. Lead shields the detector array from the background radiation. Additionally, a CCD camera is attached to the top of the gamma camera and provides coincident 2D visual information. The inferred distances from the center of the two measurement points and a radiation source had less than a 3% error within a range of 3m. The radiation image from the gamma camera and the visual image from CCD camera are superimposed into one combined image using a maximum-likelihood (ML) algorithm to make the image more precise. The response functions for the ML algorithm depend on the energy of incident radiation, and are obtained from both experiments and simulations. The energy-dependent response functions are shown to yield better imaging performance compared with the fixed energy response function commonly used previously.

  7. Advisory Committee on human radiation experiments. Final report, Supplemental Volume 2. Sources and documentation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    This volume and its appendixes supplement the Advisory Committee`s final report by reporting how we went about looking for information concerning human radiation experiments and intentional releases, a description of what we found and where we found it, and a finding aid for the information that we collected. This volume begins with an overview of federal records, including general descriptions of the types of records that have been useful and how the federal government handles these records. This is followed by an agency-by-agency account of the discovery process and descriptions of the records reviewed, together with instructions on how to obtain further information from those agencies. There is also a description of other sources of information that have been important, including institutional records, print resources, and nonprint media and interviews. The third part contains brief accounts of ACHRE`s two major contemporary survey projects (these are described in greater detail in the final report and another supplemental volume) and other research activities. The final section describes how the ACHRE information-nation collections were managed and the records that ACHRE created in the course of its work; this constitutes a general finding aid for the materials deposited with the National Archives. The appendices provide brief references to federal records reviewed, descriptions of the accessions that comprise the ACHRE Research Document Collection, and descriptions of the documents selected for individual treatment. Also included are an account of the documentation available for ACHRE meetings, brief abstracts of the almost 4,000 experiments individually described by ACHRE staff, a full bibliography of secondary sources used, and other information.

  8. Modelled radiative effects of sea spray aerosol using a source function encapsulating wave state

    Science.gov (United States)

    Partanen, Antti-Ilari; Dunne, Eimear M.; Bergman, Tommi; Laakso, Anton; Kokkola, Harri; Ovadnevaite, Jurgita; Sogacheva, Larisa; Baisnée, Dominique; Sciare, Jean; Manders, Astrid; O'Dowd, Colin; de Leeuw, Gerrit; Korhonen, Hannele

    2014-05-01

    Sea spray aerosol particles have significant effects on global climate by scattering solar radiation (direct effect) and modifying cloud properties (indirect effect). Sea spray consists mainly of sea salt, but in biologically active regions, major fraction of sea spray may come in the form of primary marine organic matter (PMOM). Traditionally, sea spray flux has been parameterized in global models in terms of wind speed, and organic fraction of sea spray in terms of chlorophyll-a concentration. In this study, we have incorporated recently developed parameterizations for the sea spray aerosol source flux into the global aerosol-climate model ECHAM-HAMMOZ. The parameterizations encapsulate the wave state via Reynolds number, and predict the organic fraction of the sea spray aerosol source flux. The model was then used to investigate the direct and indirect effects of sea spray aerosol particles. We compared simulated sea spray concentrations with in-situ measurements from Mace Head (North Atlantic), Point Reyes (North Pacific), and Amsterdam Island (Southern Indian Ocean). Aerosol optical depth (AOD) was compared with satellite measurements from PARASOL. Modelled annual mean global emissions of sea salt and PMOM were 805 Tg yr-1 (uncertainty range of 378-1233 Tg yr-1) and 1.1 Tg yr-1 (0.5-1.8 Tg yr-1), respectively. Sea salt emissions were considerably lower than the majority of previous estimates, but PMOM was in the range of previous studies. The model captured sea salt concentrations fairly well in the smaller size ranges at Mace Head (annual normalized mean bias of -13% for particles with vacuum aerodynamic diameter Dva

  9. Analysis of radiation environmental safety for China's Spallation Neutron Source (CSNS)

    Science.gov (United States)

    Wang, Qing-Bin; Wu, Qing-Biao; Ma, Zhong-Jian; Zhang, Qing-Jiang; Li, Nan; Wu, Jing-Min; Liu, Jian; Zhang, Gang

    2010-07-01

    The China Spallation Neutron Source (CSNS) is going to be located in Dalang Town, Dongguan City in the Guangdong Province. In this paper we report the results of the parameters related with environment safety based on experiential calculations and Monte Carlo simulations. The main project of the accelerator is an under ground construction. On top there is a 0.5 m concrete and 5.0 m soil covering for shielding, which can reduce the dose out of the tunnel's top down to 0.2 μSv/h. For the residents on the boundary of the CSNS, the dose produced by skyshine, which is caused by the penetrated radiation leaking from the top of the accelerator, is no more than 0.68 μSv/a. When CSNS is operating normally, the maximal annual effective dose due to the emission of gas from the tunnel is 2.40×10-3 mSv/a to the public adult, and 2.29×10-3 mSv/a to a child, both values are two orders of magnitude less than the limiting value for control and management. CSNS may give rise to an activation of the soil and groundwater in the nearest tunnels, where the main productions are 3H, 7Be, 22Na, 54Mn, etc. But the specific activity is less than the exempt specific activity in the national standard GB13376-92. So it is safe to say that the environmental impact caused by the activation of soil and groundwater is insignificant. To sum up, for CSNS, as a powerful neutron source device, driven by a high-energy high-current proton accelerator, a lot of potential factors affecting the environment exist. However, as long as effective shieldings for protection are adopted and strict rules are drafted, the environmental impact can be kept under control within the limits of the national standard.

  10. Detection of embedded radiation sources using temporal variation of gamma spectral data.

    Energy Technology Data Exchange (ETDEWEB)

    Shokair, Isaac R.

    2011-09-01

    Conventional full spectrum gamma spectroscopic analysis has the objective of quantitative identification of all the isotopes present in a measurement. For low energy resolution detectors, when photopeaks alone are not sufficient for complete isotopic identification, such analysis requires template spectra for all the isotopes present in the measurement. When many isotopes are present it is difficult to make the correct identification and this process often requires many trial solutions by highly skilled spectroscopists. This report investigates the potential of a new analysis method which uses spatial/temporal information from multiple low energy resolution measurements to test the hypothesis of the presence of a target spectrum of interest in these measurements without the need to identify all the other isotopes present. This method is referred to as targeted principal component analysis (TPCA). For radiation portal monitor applications, multiple measurements of gamma spectra are taken at equally spaced time increments as a vehicle passes through the portal and the TPCA method is directly applicable to this type of measurement. In this report we describe the method and investigate its application to the problem of detection of a radioactive localized source that is embedded in a distributed source in the presence of an ambient background. Examples using simulated spectral measurements indicate that this method works very well and has the potential for automated analysis for RPM applications. This method is also expected to work well for isotopic detection in the presence of spectrally and spatially varying backgrounds as a result of vehicle-induced background suppression. Further work is needed to include effects of shielding, to understand detection limits, setting of thresholds, and to estimate false positive probability.

  11. An isotopic analysis of ionising radiation as a source of sulphuric acid

    Directory of Open Access Journals (Sweden)

    M. B. Enghoff

    2012-06-01

    Full Text Available Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a missing source. In this study the production of sulphuric acid from SO2 through a number of different pathways is investigated. The production methods are standard gas phase oxidation by OH radicals produced by ozone photolysis with UV light, liquid phase oxidation by ozone, and gas phase oxidation initiated by gamma rays. The distributions of stable sulphur isotopes in the products and substrate were measured using isotope ratio mass spectrometry. All methods produced sulphate enriched in 34S and we find an enrichment factor (δ34S of 8.7 ± 0.4‰ (1 standard deviation for the UV-initiated OH reaction. Only UV light (Hg emission at 253.65 nm produced a clear non-mass-dependent excess of 33S. The pattern of isotopic enrichment produced by gamma rays is similar, but not equal, to that produced by aqueous oxidation of SO2 by ozone. This, combined with the relative yields of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV to S(VI conversion.

  12. An isotope view on ionising radiation as a source of sulphuric acid

    Directory of Open Access Journals (Sweden)

    M. B. Enghoff

    2012-02-01

    Full Text Available Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a missing source. In this study the production of sulphuric acid from SO2 through a number of different pathways is investigated. The production methods are standard gas phase oxidation by OH radicals produced by ozone photolysis with UV light, liquid phase oxidation by ozone, and gas phase oxidation initiated by gamma rays. The distributions of stable sulphur isotopes in the products and substrate were measured using isotope ratio mass spectrometry. All methods produced sulphate enriched in 34S and we find a δ34S value of 8.7 ± 0.4‰ (1 standard deviation for the UV-initiated OH reaction. Only UV light (Hg emission at 253.65 nm produced a clear non-mass-dependent excess of 33S. The pattern of isotopic enrichment produced by gamma rays is similar, but not equal, to that produced by aqueous oxidation of SO2 by ozone. This, combined with the relative yields of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV to S(VI conversion.

  13. Studies of longitudinal profile of electron bunches and impedance measurements at Indus-2 synchrotron radiation source

    Science.gov (United States)

    Garg, Akash Deep; Yadav, S.; Kumar, Mukesh; Shrivastava, B. B.; Karnewar, A. K.; Ojha, A.; Puntambekar, T. A.

    2016-04-01

    Indus-2 is a 3rd generation synchrotron radiation source at the Raja Ramanna Centre for Advanced Technology (RRCAT) in India. We study the longitudinal profile of electrons in Indus-2 by using dual sweep synchroscan streak camera at visible diagnostic beamline. In this paper, the longitudinal profiles of electron bunch are analyzed by filling beam current in a single bunch mode. These studies are carried at injection energy (550 MeV) and at ramped beam energy (2.5 GeV). The effects of the wakefield generated interactions between the circulating electrons and the surrounding vacuum chamber are analyzed in terms of measured effects on longitudinal beam distribution. The impedance of the storage ring is obtained by fitting the solutions of Haissinski equation to the measured bunch lengthening with different impedance models. The impedance of storage ring obtained by a series R+L impedance model indicates a resistance (R) of 1350±125 Ω, an inductance (L) of 180±25 nH and broadband impedance of 2.69 Ω. These results are also compared with the values obtained from measured synchronous phase advancing and scaling laws. These studies are very useful in better understanding and control of the electromagnetic interactions.

  14. Remote Operating Monitoring Of Spatial Stability Magnets On A Kurchatov Source Of Synchrotron Radiation

    CERN Document Server

    Barkovsky, E V; Martynenko, V V; Novikov, V A; Udin, L I

    2004-01-01

    During operation of the accelerator because of a nonuniform warm -up of the ring base and constructions of installation there are angular and linear displacements of bending and focusing magnets of a Big Accelerator Ring (BR) of a Kurchatov Source of Synchrotron Radiation. With the purpose of remote operating monitoring of a spatial position of elements BR was used anglemetrical control and measuring system with digital and analog registration in a real time mode. The results of the first stage of a monitoring BR have shown high informativity of the given instrumental - methodical means. The basic radiants of cyclical thermoelastic alternating strains are detected; the amplitudes of angular and linear displacements of magnets from different internal factors evaluated during operation of the accelerator. Is established, that the maximum radial angular and linear displacements of magnets are watched in 3,5-4 day after switching on of installation and achieve in max 30-35 seconds of an arc or 120-150 microns in ...

  15. The electron-cyclotron maser instability as a source of plasma radiation. [Solar radio bursts

    Science.gov (United States)

    Winglee, R. M.; Dulk, G. A.

    1986-01-01

    The generation of continuum bursts from the sun at dm and m wavelengths (in particular, type IV bursts) via the electron-cyclotron-maser instability is examined. The maser instability can be driven by an electron distribution with either a loss-cone anisotropy or a peak at large pitch angles. For omega(p)/Omega(e) much greater than 1, the maser emission is produced by electrons interacting through a harmonic (cyclotron) resonance and is electrostatic, being in the upper hybrid mode at frequencies approximately equal to omega(p). Coalescence processes are required to convert the electrostatic waves into transverse radiation which can escape from the source region. Whether the resultant spectrum is nearly a smooth continuum or has a zebra-stripe pattern (both of which occur in type IV bursts) depends on the form of the electron distribution, inhomogeneities in the density and magnetic field, and whether the maser reaches saturation. For at least the case of some type IV dm bursts with fine structure, comparison with observations seems to indicate that the electrons producing the emission are more likely to have a loss-cone distribution, and that the maser instability is not at saturation.

  16. Accelerator-based neutron source using a cold deuterium target with degenerate electrons

    Directory of Open Access Journals (Sweden)

    R. E. Phillips

    2013-07-01

    Full Text Available A neutron generator is considered in which a beam of tritons is incident on a hypothetical cold deuterium target with degenerate electrons. The energy efficiency of neutron generation is found to increase substantially with electron density. Recent reports of potential targets are discussed.

  17. Investigation of gamma-ray fingerprint identifying mechanism for the types of radiation sources

    CERN Document Server

    Liu Su Ping; Gu Dang Chang; Gong-Jian; Hao Fan Hua; Hu Guang Chun

    2002-01-01

    Radiation fingerprints sometimes can be used to label and identify the radiation resources. For instance, in a future nuclear reduction treaty that requires verification of irreversible dismantling of reduced nuclear warheads, the radiation fingerprints of nuclear warheads are expected to play a key role in labelling and identifying the reduced warheads. It would promote the development of nuclear warheads deep-cuts verification technologies if authors start right now some investigations on the issues related to the radiation fingerprints. The author dedicated to the investigation of gamma-ray fingerprint identifying mechanism for the types of radiation resources. The purpose of the identifying mechanism investigation is to find a credible way to tell whether any two gamma-ray spectral fingerprints that are under comparison are radiated from the same resource. The authors created the spectrum pattern comparison (SPC) to study the comparability of the two radiation fingerprints. Guided by the principle of SPC,...

  18. Study of the source term of radiation of the CDTN GE-PET trace 8 cyclotron with the MCNPX code

    Energy Technology Data Exchange (ETDEWEB)

    Benavente C, J. A.; Lacerda, M. A. S.; Fonseca, T. C. F.; Da Silva, T. A. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Vega C, H. R., E-mail: jhonnybenavente@gmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    Full text: The knowledge of the neutron spectra in a PET cyclotron is important for the optimization of radiation protection of the workers and individuals of the public. The main objective of this work is to study the source term of radiation of the GE-PET trace 8 cyclotron of the Development Center of Nuclear Technology (CDTN/CNEN) using computer simulation by the Monte Carlo method. The MCNPX version 2.7 code was used to calculate the flux of neutrons produced from the interaction of the primary proton beam with the target body and other cyclotron components, during 18F production. The estimate of the source term and the corresponding radiation field was performed from the bombardment of a H{sub 2}{sup 18}O target with protons of 75 μA current and 16.5 MeV of energy. The values of the simulated fluxes were compared with those reported by the accelerator manufacturer (GE Health care Company). Results showed that the fluxes estimated with the MCNPX codes were about 70% lower than the reported by the manufacturer. The mean energies of the neutrons were also different of that reported by GE Health Care. It is recommended to investigate other cross sections data and the use of physical models of the code itself for a complete characterization of the source term of radiation. (Author)

  19. Ingestion of polonium ((210)Po) via dietary sources in high background radiation areas of south India.

    Science.gov (United States)

    Arunachalam, Kantha Deivi; Baskaran, Kamesh Viswanathan; Rao, D D; Sathyapriya, R; Annamalai, Sathesh Kumar; Kuruva, Jaya Krishna; Hari, Shanmugamsundaram

    2014-10-01

    To study the distribution of Polonium ((210)Po) activity in dietary sources in the high background radiation zone of Puttetti in southern Tamil Nadu. (210)Po was analyzed in the food materials consumed by the male and female individual representatives living in the high background areas by 24-h Duplicate Diet Study (DDS) and Market Basket Study (MBS). The MBS was performed by collecting the food samples such as, cereals, fruits, leafy vegetables, roots and tubers, other vegetables, fish, meat and milk grown in the high background radiation zone of southern Tamil Nadu as a part of baseline study in this region. The DDS was done by collecting the food materials consumed including the beverages in 24 h from different age groups of male and female individuals living in the village of Puttetti. The intake and ingestion dose of the radionuclide (210)Po was estimated. The average concentration of (210)Po in DDS (n = 33) was found to be 74 mBq.kg(- 1) of fresh weight. The MBS was collected based on food consumption representing more than 85-95% of annual supply, and were divided into eight food groups. The average concentration of (210)Po in the eight food groups namely leafy vegetables was 2176 mBq.kg(- 1) (n = 3), vegetables 55 mBq.kg(- 1) (n = 10), roots and tubers 251 mBq.kg(- 1) (n = 4), fruits 65 mBq.kg(- 1) (n = 5), fish 345 mBq.kg(- 1) (n = 2), meat food 117 mBq.kg(- 1) (n = 3), milk 20 mBq.kg(- 1) (n = 1) and cereal 290 (n = 1) mBq.kg(- 1) of fresh weight, respectively. The annual intake and ingestion dose due to (210)Po was estimated by DDS and MBS in adults, adolescents and children. The overall results showed that the MBS was moderately higher than the DDS in all age groups. Moreover, a DDS approach may even be more realistic, as cooked foodstuffs are used for dietary exposure assessment. The study confirms that the current levels of (210)Po do not pose a significant radiological risk to the local inhabitants.

  20. Analysis of accelerator based neutron spectra for BNCT using proton recoil spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wielopolski, L.; Ludewig, H.; Powell, J.R.; Raparia, D.; Alessi, J.G.; Lowenstein, D.I.

    1999-03-01

    Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase 1/2 clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra, alternative neutron sources are being contemplated for wider implementation of this modality in a hospital environment. For example, accelerator based neutron sources offer the possibility of tailoring the neutron beams, in terms of improved depth-dose distributions, to the individual and offer, with relative ease, the capability of modifying the neutron beam energy and port size. In previous work new concepts for compact accelerator/target configuration were published. In this work, using the Van de Graaff accelerator the authors have explored different materials for filtering and reflecting neutron beams produced by irradiating a thick Li target with 1.8 to 2.5 MeV proton beams. However, since the yield and the maximum neutron energy emerging from the Li-7(p,n)Be-7 reaction increase with increase in the proton beam energy, there is a need for optimization of the proton energy versus filter and shielding requirements to obtain the desired epithermal neutron beam. The MCNP-4A computer code was used for the initial design studies that were verified with benchmark

  1. ANALYSIS OF ACCELERATOR BASED NEUTRON SPECTRA FOR BNCT USING PROTON RECOIL SPECTROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    WIELOPOLSKI,L.; LUDEWIG,H.; POWELL,J.R.; RAPARIA,D.; ALESSI,J.G.; LOWENSTEIN,D.I.

    1998-11-06

    Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase I/II clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra alternative neutron sources are being contemplated for wider implementation of this modality in a hospital environment. For example, accelerator based neutron sources offer the possibility of tailoring the neutron beams, in terms of improved depth-dose distributions, to the individual and offer, with relative ease, the capability of modifying the neutron beam energy and port size. In previous work new concepts for compact accelerator/target configuration were published. In this work, using the Van de Graaff accelerator the authors have explored different materials for filtering and reflecting neutron beams produced by irradiating a thick Li target with 1.8 to 2.5 MeV proton beams. However, since the yield and the maximum neutron energy emerging from the Li-7(p,n)Be-7 reaction increase with increase in the proton beam energy, there is a need for optimization of the proton energy versus filter and shielding requirements to obtain the desired epithermal neutron beam. The MCNP-4A computer code was used for the initial design studies that were verified with benchmark

  2. High power THz source based on coherent radiation of picosecond relativistic electron bunch train

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Tunable and compact high power terahertz (THz) radiation based on coherent radiation (CR) of the picosecond relativistic electron bunch train is under development at the Tsinghua accelerator lab. Coherent synchronization radiation (CSR) and coherent transition radiation (CTR) are researched based on an S-band compact electron linac, a bending magnet or a thin foil. The bunch train’s form factors, which are the key factor of THz radiation, are analyzed by the PARMELA simulation. The effects of electron bunch trains under different conditions, such as the bunch number, bunch charges, micro-pulses inter-distance, and accelerating gradient of the gun are investigated separately in this paper. The optimal radiated THz power and spectra should take these factors as a whole into account.

  3. Unexpected Up/Down asymmetry measured in axial radiation exiting high-temperature dynamic-hohlraum x-ray source

    Science.gov (United States)

    Sanford, T. W. L.; Lemke, R. W.; Mock, R. C.; Oliver, B. V.; Chandler, G. A.; Leeper, R. J.; Mehlhorn, T. A.; Nash, T. J.; Ruiz, C. L.; Waisman, E. M.; Peterson, D. L.; Chrien, R. E.; Idzorek, G. C.; Watt, R. G.; Roderick, N. F.; Haines, M. G.

    2002-11-01

    A 10 TW radiation source has been developed on the 20-MA Z facility that produces a high-temperature ( 215 eV) x-ray pulse. The pulse is generated in the positive z-direction through a REH (radiation exit hole), primarily from the interior of a collapsing dynamic-hohlraum (DH) centered within a z-pinch [1]. By adding an identical REH at the bottom of the hohlraum, radiation generated in the negative z direction through the bottom offers the possibility of doubling the utility of the hohlraum. Because of the up/down symmetry of the DH about the mid-plane of the z-axis (aside from the power feed), a radiation pulse similar to that exiting the top-REH (anode) is expected leaving the bottom-REH (cathode). Measurements indicate, however, that the peak radiated power exiting the top-REH is 2±0.2 times that exiting the bottom-REH. In contrast, the total energy radiated from either REH is about the same. Detailed measurements of this unexpected asymmetry, apparently dependent on polarity, together with potential origins of the asymmetry are discussed. [1] T. W. L. Sanford, et al, in press, Phys. Plasmas 9, (Aug. 2002). *Sandia is a multi-program laboratory operated by the Sandia Corporation, a Lockheed Martin Company, for the U.S. DOE under Contract No. DE-AC04-94AL85000.

  4. An assessment of bias and uncertainty in recorded dose from external sources of radiation for workers at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Fix, J.J.; Gilbert, E.S.; Baumgartner, W.V.

    1994-08-01

    Worker dose estimates are used in epidemiologic studies of nuclear workers. A major objective of these studies is to provide a direct assessment of the carcinogenic risk of exposure to ionizing radiation at low doses and dose rates. If dose estimates used in analyses of worker data are biased, then risk estimates expressed per unit of dose will also be biased. In addition, random error in dose estimates may lead to underestimation of risk coefficients and can also distort dose-response analyses. Analyses of data from nuclear worker studies, including Hanford, have typically not been adjusted for biases and uncertainties in dose estimates in part because of the lack of adequate information on the nature and magnitude of these biases and uncertainties. This report describes an approach used to assess bias and uncertainty in radiation dose for Hanford dosimetry systems. The approach can be considered as an elaboration of work conducted by a technical committee appointed by the National Academy of Sciences (NAS) used to quantify the bias and uncertainty in estimated doses for personnel exposed to radiation as a result of atmospheric testing of nuclear weapons between 1945 and 1962. In addition, laboratory studies were conducted to measure bias for selected sources of photon radiation resulting from angular response characteristics of Hanford dosimeter systems. An overall assessment is presented of bias and uncertainty for photon radiation greater than 100 keV. This radiation is expected to have caused the vast majority of recorded dose for Hanford workers.

  5. Generation and healing behavior of radiation-induced optical absorption in fluoride phosphate glasses: The dependence on UV radiation sources and temperature

    Science.gov (United States)

    Natura, U.; Ehrt, D.

    2001-03-01

    High purity fluoride phosphate (FP) glasses have a large transmission range from the vacuum ultraviolet to the infrared. They are attractive candidates for lens systems in microlithography equipment and excimer laser optics. Fluoride single crystals and vitreous silica are well-known traditional materials for ultraviolet optics. Crystal sizes are limited and glass is better for fabricating optics. For lens systems, a variety of glasses with different refractive indices and dispersion are required. The UV resonance wavelengths of FP glasses with a low content of phosphate using a two-term Sellmeier dispersion formula are comparable with those of silica and fluoride single crystals. It is known, that UV radiation induces the generation of several defect centers leading to additional absorption bands. The investigation of the kinetics of defect generation is very important for the prediction of transmission losses in case of long-time irradiation. To predict the kinetics of defect generation, first the separation of absorption bands is necessary. Experiments were carried out using UV-lamps, the KrF excimer laser (ns- and fs-pulses) and the ArF excimer laser (ns-pulses). The healing behavior of radiation-induced absorption bands was investigated using thermal treatment (temperature-dependence) and bleaching experiments (radiation-dependence). The results of these experiments enable the separation of absorption bands and the prediction of the defect generation depending on the used radiation source. The healing of strong defects at room temperature is postulated to be a diffusion-controlled process.

  6. The source of THz radiation based on dielectric waveguide excited by sequence of electron bunches

    Science.gov (United States)

    Altmark, A. M.; Kanareykin, A. D.

    2016-07-01

    We present a new method for excitation of THz Cherenkov radiation in a dielectric waveguide by relativistic electron bunches. A sequence of bunches generates monochromatic radiation. The frequency of radiation is defined by the distance between the bunches. The studies were carried by using the newly updated BBU-3000 code which permits taking into account a number of additional options: an external quadrupole focusing system, group velocity of the wakefield, and the dielectric material loss factor. In this paper, we present our algorithm for optimizing the number and sequential positions of bunches for generation of narrow band high power THz radiation.

  7. Evaluation of shelf life of tomatoes after using radiation with cobalt-60 source

    Energy Technology Data Exchange (ETDEWEB)

    Vicalvi, Maria Claudia V.; Solidonio, Evelyne G.; Melo, Patryk; Silva, Marcio Albuquerque da; Junior, Carlos Eduardo de O.C.; Silva, Glezia Renata da; Sena, Kesia Xisto F.R. de; Colaco, Waldeciro, E-mail: claudiavicalvi@hotmail.com, E-mail: k.xisto@gmail.com, E-mail: wcolaco@ufpe.com.br [Universidade Federal de Pernanbuco (UFPE), Pernambuco, PE (Brazil)

    2013-07-01

    Tomato is one of the most consumed fruits in the world and also one of the agricultural products with most losses due to its high perishability. The objective of this research was to evaluate the increased length of shelf life of tomatoes sold in the CEASA-PE through the use of radiation in doses of 1, 1.5 and 2 kGy with Cobalt-60 source. The study used three lots of 100 tomatoes each. Of which, 25 of them were used as the control group and 75 were irradiated with one of 3 different doses. The evaluation of the shelf life of tomatoes before and after use of the radiation was made from the observation of the visual aspects of the initiation of the fruit sto decay. The samples were analyzed at of every seven days. The fruit treated as the control group of the first batch were viable with no signs of decay for more than one month wrapped in sterile plastic wrap and stored at environment temperature ± 25 deg C. It was observed that at the dose of 1.0 kGy there was a delay in the induction of shelf life over 14 days. When used a dose of 1.5 kGy there was an increase of 30 days on shelf life compared with the control group. At a dose of 2.0 kGy, the tomatoes have a shelf life of 92 days. In the second batch of fruits, the duration of tomatoes of the control group was 40 days. At a dose of 1.0 kGy was an increase of 15 days compared to control fruits. When applying the dose of 1.5 kGy, the lifetime of the fruit was 70 days and at the dose of 2.0 kGy fruits were of 106 days starting from the initial date of experiment. The third and final batch,the lifetime of the fruits were not higher than those found in previous batches, the control group had a permanence of 14 days. At the dose of 1.0 kGy, there was the additional 10 days compared to the control group. At a dose of 1.5 kGy was observed that the fruits lasted 35 days starting from the initial day of the experiment and the tomatoes that were irradiated at 2.0 kGy the duration was 45 days from the start date of the

  8. An accelerator-based epithermal neutron beam design for BNCT and dosimetric evaluation using a voxel head phantom.

    Science.gov (United States)

    Lee, Deok-jae; Han, Chi Young; Park, Sung Ho; Kim, Jong Kyung

    2004-01-01

    The beam shaping assembly design has been investigated in order to improve the epithermal neutron beam for accelerator-based boron neutron capture therapy in intensity and quality, and dosimetric evaluation for the beams has been performed using both mathematical and voxel head phantoms with MCNP runs. The neutron source was assumed to be produced from a conventional 2.5 MeV proton accelerator with a thick (7)Li target. The results indicate that it is possible to enhance epithermal neutron flux remarkably as well as to embody a good spectrum shaping to epithermal neutrons only with the proper combination of moderator and reflector. It is also found that a larger number of thermal neutrons can reach deeply into the brain and, therefore, can reduce considerably the treatment time for brain tumours. Consequently, the epithermal neutron beams designed in this study can treat more effectively deep-seated brain tumours.

  9. The BSA modeling for the accelerator-based BNCT facility at INFN LNL for treating shallow skin melanoma.

    Science.gov (United States)

    Ceballos, C; Esposito, J

    2009-07-01

    The SPES-BNCT ongoing project of the Istituto Nazionale di Fisica Nucleare (INFN) is aimed at the construction at the Laboratori Nazionali di Legnaro (LNL) of an accelerator-based (AB), high-flux thermal neutron beam facility devoted to boron neutron capture therapy (BNCT) experimental treatment of extended skin melanoma, in the framework of SPES (selective production of exotic species) project. The neutron source will be produced via the (9)Be(p,xn) reactions by a 5 MeV, 30 mA proton beam into a thick beryllium target. The resulting neutron spectrum is slowed down using a beam shaping assembly (BSA), for which modeling is in an advanced neutronic design stage. An overview on the BSA current status, based on the Be neutron converter prototype designed and already constructed, is reported.

  10. 3D computational and experimental radiation transport assessments of Pu-Be sources and graded moderators for parcel screening

    Science.gov (United States)

    Ghita, Gabriel; Sjoden, Glenn; Baciak, James; Huang, Nancy

    2006-05-01

    The Florida Institute for Nuclear Detection and Security (FINDS) is currently working on the design and evaluation of a prototype neutron detector array that may be used for parcel screening systems and homeland security applications. In order to maximize neutron detector response over a wide spectrum of energies, moderator materials of different compositions and amounts are required, and can be optimized through 3-D discrete ordinates and Monte Carlo model simulations verified through measurement. Pu-Be sources can be used as didactic source materials to augment the design, optimization, and construction of detector arrays with proper characterization via transport analysis. To perform the assessments of the Pu-Be Source Capsule, 3-D radiation transport computations are used, including Monte Carlo (MCNP5) and deterministic (PENTRAN) methodologies. In establishing source geometry, we based our model on available source schematic data. Because both the MCNP5 and PENTRAN codes begin with source neutrons, exothermic (α,n) reactions are modeled using the SCALE5 code from ORNL to define the energy spectrum and the decay of the source. We combined our computational results with experimental data to fully validate our computational schemes, tools and models. Results from our computational models will then be used with experiment to generate a mosaic of the radiation spectrum. Finally, we discuss follow-up studies that highlight response optimization efforts in designing, building, and testing an array of detectors with varying moderators/thicknesses tagged to specific responses predicted using 3-D radiation transport models to augment special nuclear materials detection.

  11. Treatment of arteriovenous malformations with linear accelerator-based radiosurgery compared with Gamma Knife surgery.

    Science.gov (United States)

    Orio, Peter; Stelzer, Keith J; Goodkin, Robert; Douglas, James G

    2006-12-01

    The authors sought to compare the outcomes of patients with arteriovenous malformations (AVMs) treated by Gamma Knife surgery (GKS) with those of patients treated by linear accelerator-based (LINAC) radiosurgery. One hundred and eighty-seven patients with AVMs were treated at our institution between 1992 and 2003. Ninety-one patients were treated with GKS and 96 patients were treated with LINAC radiosurgery. Patient and treatment characteristics in the two groups included the following. In the LINAC group, the median age was 33 years (range 9-66 years); the median dose was 16 Gy (70% isodose line); the median treated AVM volume was 5.5 cm3; and 46% of patients in this group were treated after hemorrhage. In the GKS group, the median age was 38 years (range 6-63 years); the median dose was 20 Gy (50% isodose line); the median treated AVM volume was 4.3 cm3; and 44% of patients in this group were treated after hemorrhage. Obliteration of AVMs was determined by performing computed tomography (CT) angiography and/or magnetic resonance (MR) angiography and angiography. Patient follow-up evaluation included obtaining an MR angiogram/MR image or CT angiogram at 6 months, at 1 year, and then annually thereafter. Angiography was performed to confirm obliteration when MR angiography and/or CT angiography no longer revealed evidence of an AVM. The 5-year estimated AVM obliteration rate was 66% in the entire patient group; the LINAC group was 60%; the GKS group was 72%; this difference was not statistically significant (p = 0.97). Twelve patients who underwent treatment with LINAC radiosurgery underwent retreatment with GKS and one was retreated with LINAC radiosurgery. The obliteration rate was 82%. Six patients treated with GKS were retreated with GKS, but the follow-up time is of short duration. Chronic toxicity occurred in 8% of both the GKS and the LINAC groups (p = 0.61). Posttreatment hemorrhage during the time of risk before AVM obliteration was 13% in the GKS group

  12. Impulse powerful UV-radiation source pumped by the sublight ionization waves for the bacteriological disinfection of water

    Science.gov (United States)

    Filiouguine, Igor V.; Kostiouchenko, S. V.; Koudryavtsev, N. N.; Vasilyak, Leonid M.; Yakimenko, A. V.

    1993-11-01

    The bacteriological disinfective action of UV-radiation is well known. The pioneer work on UV-radiation used for bacteriological disinfection of waste water was made in 1910. Because of the high cost and low living time of the UV-radiation sources, the alternative technique for waste water purification by chlorine introducing was spread out. During the second stage of the UV purification development, beginning in approximately 1970, the interest for bacteriological cleaning of water, increased again. Two reasons were responsible for this event: first, the significant improvement of technology and design of UV-bacteriological purificators, and second, recognition of the serious danger of chlorine compounds introduced into water under purification because of the toxicity of these compounds. Further investigations gave excellent results in the creation and industrial applications of UV- bacteriological purificators. Now we can see a rapid development of industrial technology in UV-purification of drinking and waste waters.

  13. Evaluation of the Earth Radiation Budget Experiment (ERBE) shortwave channel's stability using in-flight calibration sources

    Science.gov (United States)

    Gibson, Michael A.; Lee, Robert B., III; Thomas, Susan

    1992-01-01

    The Earth Radiation Budget Experiment (ERBE) radiometers were designed to make absolute measurements of the incoming solar, earth-reflected solar, and earth-emitted fluxes for investigations of the earth's climate system. Thermistor bolometers were the sensors used for the ERBE scanning radiometric package. Each thermistor bolometer package consisted of three narrow field of view broadband radiometric channels measuring shortwave, longwave, and total (0.2 micron to 50 microns) radiation. The in-flight calibration facilities include Mirror Attenuator Mosaics, shortwave internal calibration source, and internal blackbody sources to monitor the long-term responsivity of the radiometers. This paper describes the in-flight calibration facilities, the calibration data reduction techniques, and the results from the in-flight shortwave channel calibrations. The results indicate that the ERBE shortwave detectors were stable to within +/- 1 percent for up to five years of flight operation.

  14. High-resolution terahertz spectroscopy with a noise radiation source based on high-T c superconductors

    Science.gov (United States)

    Sobakinskaya, E.; Vaks, V. L.; Kinev, N.; Ji, M.; Li, M. Y.; Wang, H. B.; Koshelets, V. P.

    2017-01-01

    Stochastic fields can play a ‘constructive’ role in their interaction with quantum systems. In this paper, we demonstrate that the phase-diffusion field (PDF) in the terahertz range (THz) induces macroscopic polarization in molecular gas. We explain the observed effect using a simple model in which the PDF is treated as a series of ultrashort pulses of a regular signal, resulting in transient absorption in molecular gas. The experimental investigation of this effect is carried out using ammonia, and the PDF is generated by an oscillator based on stacks of Bi2Sr2CaCu2O8 intrinsic Josephson junctions. These radiation sources do not require a phase-lock loop system to provide high resolution, which simplifies the spectrometer considerably. The PDF radiation sources open up new horizons for the development of compact high-resolution THz spectrometers and applications thereof.

  15. Buoyancy-Driven Radiative Unsteady Magnetohydrodynamic Heat Transfer over a Stretching Sheet with non-Uniform Heat Source/sink

    Directory of Open Access Journals (Sweden)

    Dulal Pal

    2016-01-01

    Full Text Available In the present study an unsteady mixed convection boundary layer flow of an electrically conduct- ing fluid over an stretching permeable sheet in the presence of transverse magnetic field, thermal radiation and non-uniform heat source/sink effects is investigated. The unsteadiness in the flow and temperature fields is due to the time-dependent nature of the stretching velocity and the surface temperature. Both opposing and assisting flows are considered. The dimensionless governing or- dinary non-linear differential equations are solved numerically by applying shooting method using Runge-Kutta-Fehlberg method. The effects of unsteadiness parameter, buoyancy parameter, thermal radiation, Eckert number, Prandtl number and non-uniform heat source/sink parameter on the flow and heat transfer characteristics are thoroughly examined. Comparisons of the present results with previously published results for the steady case are found to be excellent.

  16. Spatiotemporal characteristics of the energy radiation sources of the three great earthquakes near Sumatra Island in September 2007

    Institute of Scientific and Technical Information of China (English)

    XU LiSheng; DU HaiLin; ZHANG HongXia; ZHANG Yong; LI ChunLai; ZHAO Hua

    2008-01-01

    Three strong earthquakes with magnitudes of Mw 8.4, Mw 7.9 and Mw 7.0 occurred in the sea west of Sumatra island on September 12 and 13, 2007. We relocated the epicenters and focal depths of the three events by means of the reversal-time imaging technique using broadband digital seismic data from worldwide stations ranging from 30°to 90°, imaged the spatiotemporal variation of the energy radiation sources by means of the nonplane wave array technique using the broadband digital seismic data from a generalized array made up of 33 stations of the Capital Region Digital Seismograph Network (CRDSN), and obtained the rupture duration times, extents and rupture velocities. Also, we discussed the correlations between the locations of the energy radiation sources of the three events.

  17. From single photons to milliwatt radiant power-electron storage rings as radiation sources with a high dynamic range

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R.; Thornagel, R.; Ulm, G. [Physikalisch-Technische Bundesanstalt, Berlin (Germany)

    2010-10-15

    The spectral radiant intensity of synchrotron radiation from electron storage rings can be calculated from basic electrodynamic relations (Schwinger equation) and it is directly proportional to the stored electron beam current, i.e. the number of stored electrons. With the necessary equipment installed to measure and control the electron beam current over a wide dynamic range, the radiant intensity of the synchrotron radiation can be adjusted accordingly without changing the spectrum. This is done, e.g., at the Metrology Light Source (MLS), the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt. The MLS is operated as a primary radiation source standard from the near IR up to the soft x-ray region and its operational parameters can be adjusted and accurately measured in a wide range: the electron beam current can be varied from 1 pA (one stored electron) up to 200 mA and thus the radiant intensity can be changed by more than 11 decades. The photon flux or radiant power for typical angular acceptances can thus be varied from single photons to milliwatts. This is a very powerful tool, e.g., for the characterization of the linearity of the response of radiation detectors or for the calibration of photon counting detectors. In this article we present an overview of past, current and possible future activities exploiting this feature. (authors)

  18. A Note on the Analysis of Electrodynamic Fields Radiated by Time-Harmonic Sources Within Non-Birefringent Anisotropic Media

    CERN Document Server

    Sainath, Kamalesh

    2015-01-01

    We address a challenge concerning the spectral-domain-based analysis of electromagnetic fields produced by time-harmonic current sources within planar-layered media, which arises specifically when sources are embedded inside non-birefringent anisotropic medium (NBAM) layers. In NBAM, the highly symmetric permeability and permittivity tensors can induce directionally-dependent, but polarization independent, propagation properties supporting "degenerate" characteristic polarizations. That is to say, the considered NBAM support four linearly independent field polarization eigenvectors associated with only two (rather than four) unique, non-defective eigenvalues. We explain problems that can arise when the source(s) specifically reside within NBAM planar layers when using canonical field expressions as well as obtain alternative expressions, immune to such problems, that form the foundation for a robust eigenfunction-based analysis of electromagnetic radiation and scattering within planar-layered media.

  19. Study on effect of geometrical configuration of radioactive source material to the radiation intensity of betavoltaic nuclear battery

    Energy Technology Data Exchange (ETDEWEB)

    Badrianto, Muldani Dwi; Riupassa, Robi D.; Basar, Khairul, E-mail: khbasar@fi.itb.ac.id [Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung (Indonesia)

    2015-09-30

    Nuclear batteries have strategic applications and very high economic potential. One Important problem in application of nuclear betavoltaic battery is its low efficiency. Current efficiency of betavoltaic nuclear battery reaches only arround 2%. One aspect that can influence the efficiency of betavoltaic nuclear battery is the geometrical configuration of radioactive source. In this study we discuss the effect of geometrical configuration of radioactive source material to the radiation intensity in betavoltaic nuclear battery system. received by the detector. By obtaining the optimum configurations, the optimum usage of radioactive materials can be determined. Various geometrical configurations of radioactive source material are simulated. It is obtained that usage of radioactive source will be optimum for circular configuration.

  20. Analytical formulae to calculate the solid angle subtended at an arbitrarily positioned point source by an elliptical radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, Mahmoud I., E-mail: mabbas@physicist.net [Physics Department, Faculty of Science, Alexandria University, 21511 Alexandria (Egypt); Hammoud, Sami [Physics Department, Faculty of Science, Beirut Arab University, Beirut (Lebanon); Physics Department, Faculty of Science and Art, Lebanese International University (Lebanon); Ibrahim, Tarek; Sakr, Mohamed [Physics Department, Faculty of Science, Beirut Arab University, Beirut (Lebanon)

    2015-01-21

    In this article, we introduce a direct analytical mathematical method for calculating the solid angle, Ω, subtended at a point by closed elliptical contours. The solid angle is required in many areas of optical and nuclear physics to estimate the flux of particle beam of radiation and to determine the activity of a radioactive source. The validity of the derived analytical expressions was successfully confirmed by the comparison with some published data (Numerical Method)

  1. The potential of global solar radiation in the Silesia region as a renewable source of energy

    Directory of Open Access Journals (Sweden)

    Waniek Katarzyna

    2016-12-01

    Full Text Available Historically, Silesia has been at the centre of the Polish coal industry for many years and thus has experienced poorer air quality compared to other voivodeships. However, in recent years strong economic transformation in the area has led to a considerable reduction in coal production. This study aimed to assess the variability of global solar radiation at selected stations within the Silesian voivodeship, in order to re-evaluate the resources of renewable solar energy during the period 1994–2013. The theoretical potential of solar radiation was calculated based on a three-dimensional terrain model. The data on global solar radiation from 13 stations within the Silesia region, covering the period 1994–2013, were obtained from the Regional Inspectorate of Environmental Protection in Katowice. The most favourable conditions for the use of solar energy were found at the cities Sosnowiec and Cieszyn. The largest increase in global radiation over the research period was observed in Zabrze. The average annual global radiation ranged between 600–1300 kWh·m−2. Digital Elevation Models (DEM for selected districts of the Silesia region were used to calculate the theoretical potential of global solar radiation. The highest theoretical potential of global radiation was found in the district of Cieszyn, located at the highest altitude.

  2. [Dosimetric system for assessing doses received by people occupationally exposed to external sources of ionizing radiation].

    Science.gov (United States)

    Brodecki, Marcin; Domienik, Joanna U; Zmyślony, Marek

    2012-01-01

    The current system of dosimetric quantities has been defined by the International Commission on Radiological Protection (ICRP) and the International Commission on Radiation Units and Measurements (ICRU). Complexity of the system implies the physical nature of ionizing radiation, resulting from the presence of different types of radiation of different ionization capabilities, as well as the individual radiation sensitivity of biological material exposed. According to the latest recommendations, there are three types of dosimeter quantities relevant to radiation protection and radiological assessment of occupational exposure. These are the basic quantities, safety quantities and operational quantities. Dose limits for occupational exposure relate directly to the protection quantities, i.e. the equivalent dose and effective dose, while these quantities are practically unmeasurable in real measurement conditions. For this reason, in the system of dosimetric quantities directly measurable operating volumes were defined. They represent equivalents of the protection quantities that allow for a reliable assessment of equivalent and effective dose by conducting routine monitoring of occupational exposure. This paper presents the characteristics of these quantities, their relationships and importance in assessing individual effects of radiation. Also the methods for their implementation in personal and environmental dosimetry were showcased. The material contained in the article is a compendium of essential information about dosimetric quantities with reference to the contemporary requirements of the law, including the changed annual occupational exposure limit for the lens of the eye. The material is especially addressed to those responsible for dosimetry monitoring in the workplace, radiation protection inspectors and occupational health physicians.

  3. The pitch angle paradox and radiative life times in a synchrotron source

    CERN Document Server

    Singal, Ashok K

    2016-01-01

    In synchrotron radiation there is a paradox whether or not the pitch angle of a radiating charge varies. The conventional wisdom is that the pitch angle does not change during the radiation process. The argument is based on Larmor's radiation formula, where in a synchrotron case the radiation power is along the instantaneous direction of motion of the charge. Then the momentum loss will also be parallel to that direction and therefore the pitch angle of the charge would remain unaffected. The accordingly derived formulas for energy losses of synchrotron electrons in radio galaxies are the standard text-book material for the last 50 years. However, if we use the momentum transformation laws from special relativity, then we find that the pitch angle of a radiating charge varies. While the velocity component parallel to the magnetic field remains unaffected, the perpendicular component does reduce in magnitude due to radiative losses, implying a change in the pitch angle. This apparent paradox is resolved when e...

  4. Environmental Monitoring and Characterization of Radiation Sources on UF Campus Using a Large Volume NaI Detector

    Science.gov (United States)

    Bruner, Jesse A.; Gardiner, Hannah E.; Jordan, Kelly A.; Baciak, James E.

    2016-09-01

    Environmental radiation surveys are important for applications such as safety and regulations. This is especially true for areas exposed to emissions from nuclear reactors, such as the University of Florida Training Reactor (UFTR). At the University of Florida, surveys are performed using the RSX-1 NaI detector, developed by Radiation Solutions Inc. The detector uses incoming gamma rays and an Advanced Digital Spectrometer module to produce a linear energy spectrum. These spectra can then be analyzed in real time with a personal computer using the built in software, RadAssist. We report on radiation levels around the University of Florida campus using two mobile detection platforms, car-borne and cart-borne. The car-borne surveys provide a larger, broader map of campus radiation levels. On the other hand, cart-borne surveys provide a more detailed radiation map because of its ability to reach places on campus cars cannot go. Throughout the survey data, there are consistent radon decay product energy peaks in addition to other sources such as medical I-131 found in a large crowd of people. Finally, we investigate further applications of this mobile detection platform, such as tracking the Ar-41 plume emitted from the UFTR and detection of potential environmental hazards.

  5. Review of modeling of losses and sources of relativistic electrons in the outer radiation belt I: Radial transport

    Science.gov (United States)

    Shprits, Yuri Y.; Elkington, Scot R.; Meredith, Nigel P.; Subbotin, Dmitriy A.

    2008-11-01

    In this paper, we focus on the modeling of radial transport in the Earth's outer radiation belt. A historical overview of the first observations of the radiation belts is presented, followed by a brief description of radial diffusion. We describe how resonant interactions with poloidal and toroidal components of the ULF waves can change the electron's energy and provide radial displacements. We also present radial diffusion and guiding center simulations that show the importance of radial transport in redistributing relativistic electron fluxes and also in accelerating and decelerating radiation belt electrons. We conclude by presenting guiding center simulations of the coupled particle tracing and magnetohydrodynamic (MHD) codes and by discussing the origin of relativistic electrons at geosynchronous orbit. Local acceleration and losses and 3D simulations of the dynamics of the radiation belt fluxes are discussed in the companion paper [Shprits, Y.Y., Subbotin, D.A., Meredith, N.P., Elkington, S.R., 2008. Review of modeling of losses and sources of relativistic electrons in the outer radiation belt II: Local acceleration and loss. Journal of Atmospheric and Solar-Terrestrial Physics, this issue. doi:10.1016/j.jastp.2008.06.014].

  6. Modified blackbody radiation spectrum of a selective emitter with application to incandescent light source design.

    Science.gov (United States)

    Matsumoto, Takahiro; Tomita, Makoto

    2010-06-21

    Using a selective emitter with high emissivity in the visible wavelength region and low emissivity in the infrared wavelength region, we reduced the infrared contribution to the blackbody radiation spectrum and shifted the peak emission to shorter wavelengths. We made precise measurements of thermal radiation loss. The conversion efficiency from input electric power to visible light radiation was quantitatively evaluated with high accuracy. Using the proposed selective emitter, the conversion efficiencies in excess of 95% could be produced. Our conclusions pave the way for the design of incandescent lamps with luminous efficiencies exceeding 400 lm/W.

  7. A Critical Experimental Test of Synchrotron Radiation Theory with 3rd Generation Light Source

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2016-01-01

    A recent "beam splitting" experiment at LCLS apparently demonstrated that after a microbunched electron beam is kicked on a large angle compared to the divergence of the FEL radiation, the microbunching wave front is readjusted along the new direction of motion of the kicked beam. Therefore, coherent radiation from an undulator placed after the kicker is emitted along the kicked direction without suppression. This strong emission of coherent undulator radiation in the kicked direction cannot be explained in the framework of conventional synchrotron radiation theory. In a previous paper we explained this puzzle. We demonstrated that, in accelerator physics, the coupling of fields and particles is based, on the one hand, on the use of results from particle dynamics treated according to the absolute time convention and, on the other hand, on the use of Maxwell equations treated according to the standard (Einstein) synchronization convention. Here lies the misconception which led to the strong qualitative disagre...

  8. Comptomization and radiation spectra of X-ray sources. Calculation of the Monte Carlo method

    Science.gov (United States)

    Pozdnyakov, L. A.; Sobol, I. M.; Sonyayev, R. A.

    1980-01-01

    The results of computations of the Comptomization of low frequency radiation in weakly relativistic plasma are presented. The influence of photoabsorption by iron ions on a hard X-ray spectrum is considered.

  9. Some statistical problems inherent in radioactive-source detection. [Searching for lost radiation source with moving detector system

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, C.S.

    1978-10-12

    Some of the statistical questions associated with problems of detecting random-point-process signals embedded in random-point-process noise are examined. An example of such a problem is that of searching for a lost radioactive source with a moving detection system. The emphasis is on theoretical questions, but some experimental and Monte Carlo results are used to test the theoretical results. Several idealized binary decision problems are treated by starting with simple, specific situations and progressing toward more general problems. This sequence of decision problems culminates in the minimum-cost-expectation rule for deciding between two Poisson processes with arbitrary intensity functions. As an example, this rule is then specialized to the detector-passing-a-point-source decision problem. Finally, Monte Carlo techniques are used to develop and test one estimation procedure: the maximum-likelihood estimation of a parameter in the intensity function of a Poisson process. For the Monte Carlo test this estimation procedure is specialized to the detector-passing-a-point-source case. Introductory material from probability theory is included so as to make the report accessible to those not especially conversant with probabilistic concepts and methods. 16 figures.

  10. Dual-source computed tomography: Estimation of radiation exposure of ECG-gated and ECG-triggered coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, Dominik [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany)], E-mail: dominik.ketelsen@med.uni-tuebingen.de; Thomas, Christoph; Werner, Matthias; Luetkhoff, Marie H. [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Buchgeister, Markus [Departments of Radiotherapy and Radiooncology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Tsiflikas, Ilias; Reimann, Anja [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany); Burgstahler, Christof [Department of Cardiology, University Hospital Tuebingen, Ottfried-Mueller-Strasse 10, 72076 Tuebingen (Germany); Brodoefel, Harald; Kopp, Andreas F.; Claussen, Claus D.; Heuschmid, Martin [Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen (Germany)

    2010-02-15

    Purpose: The aim of the study was to estimate radiation exposure of coronary calcium scoring and angiography using ECG-gated and ECG-triggered dual-source computed tomography. Materials and methods: An Alderson Rando phantom equipped with thermoluminescent dosimeters was used for all dose measurements. Effective dose was calculated according to ICRP 103. Radiation exposure was performed on a dual-source computed tomography (DSCT) scanner with standard protocols for calcium scoring (DSCT-Ca) and coronary angiography (DSCTA) at different heart rates (40-100 beats/min). Furthermore, a scanning protocol with ECG-triggering as well as a standard chest CT scan were evaluated. Results: Depending on gender, heart rate and ECG-pulsing, the effective dose of a complete cardiac DSCT (DSCT-Ca and DSCTA) scan varies from 10.2 to 32.6 mSv. The effective radiation dose increased significantly with lower heart rates (p < 0.035). ECG-pulsing reduced the radiation exposure significantly in DSCTA (p < 0.001). Due to breast tissue in the primary scan range, females' doses showed an increase up to 69.9% compared to males in scan protocols without ECG-pulsing. Prospective ECG-triggered DSCTA resulted in estimated effective doses from 2.8 mSv (males) to 4.1 mSv (females). Conclusion: The ECG-pulsing technique has proven its effectiveness to reduce effective dose in coronary CT angiography and is recommended for all patients with regular heart rates. The patient's heart rate influences the radiation exposure with a significant decrease at higher heart rates. Due to its lower dose, ECG-triggered DSCTA should be implemented for special indications, i.e. for diagnosis of pathologies of the aortic root and the ascending aorta.

  11. Fiber optic Cerenkov radiation sensor system to estimate burn-up of spent fuel: characteristic evaluation of the system using Co-60 source

    Science.gov (United States)

    Shin, S. H.; Jang, K. W.; Jeon, D.; Hong, S.; Kim, S. G.; Sim, H. I.; Yoo, W. J.; Park, B. G.; Lee, B.

    2013-09-01

    Cerenkov radiation occurs when charged particles are moving faster than the speed of light in a transparent dielectric medium. In optical fibers, the Cerenkov light also can be generated due to their dielectric components. Accordingly, the radiation-induced light signals can be obtained using optical fibers without any scintillating material. In this study, to measure the intensities of Cerenkov radiation induced by gamma-rays, we have fabricated the fiber-optic Cerenkov radiation sensor system using silica optical fibers, plastic optical fibers, multi-anode photomultiplier tubes, and a scanning system. To characterize the Cerenkov radiation generated in optical fibers, the spectra of Cerenkov radiation generated in the silica and plastic optical fibers were measured. Also, the intensities of Cerenkov radiation induced by gamma-rays generated from a cylindrical Co-60 source with or without lead shielding were measured using the fiberoptic Cerenkov radiation sensor system.

  12. General relativistic radiation hydrodynamics of accretion flows - II. Treating stiff source terms and exploring physical limitations

    Science.gov (United States)

    Roedig, C.; Zanotti, O.; Alic, D.

    2012-10-01

    We present the implementation of an implicit-explicit (IMEX) Runge-Kutta numerical scheme for general relativistic (GR) hydrodynamics coupled to an optically thick radiation field in two existing GR-(magneto)hydrodynamics codes. We argue that the necessity of such an improvement arises naturally in most astrophysically relevant regimes where the optical thickness is high as the equations become stiff. By performing several simple 1D tests, we verify the codes' new ability to deal with this stiffness and show consistency. Then, still in one spatial dimension, we compute a luminosity versus accretion rate diagram for the set-up of spherical accretion on to a Schwarzschild black hole and find good agreement with previous work which included more radiation processes than we currently have available. Lastly, we revisit the supersonic Bondi-Hoyle-Lyttleton (BHL) accretion in two dimensions where we can now present simulations of realistic temperatures, down to T ˜ 106 K or less. Here we find that radiation pressure plays an important role, but also that these highly dynamical set-ups push our approximate treatment towards the limit of physical applicability. The main features of radiation hydrodynamics BHL flows manifest as (i) an effective adiabatic index approaching γeff ˜ 4/3; (ii) accretion rates two orders of magnitude lower than without radiation pressure, but still super-Eddington; (iii) luminosity estimates around the Eddington limit, hence with an overall radiative efficiency as small as ηBHL˜10-2; (iv) strong departures from thermal equilibrium in shocked regions; (v) no appearance of the flip-flop instability. We conclude that the current optically thick approximation to the radiation transfer does give physically substantial improvements over the pure hydro also in set-ups departing from equilibrium, and, once accompanied by an optically thin treatment, is likely to provide a fundamental tool for investigating accretion flows in a large variety of

  13. Attribution of aerosol radiative forcing over India during the winter monsoon to emissions from source categories and geographical regions

    Science.gov (United States)

    Verma, S.; Venkataraman, C.; Boucher, O.

    2011-08-01

    We examine the aerosol radiative effects due to aerosols emitted from different emission sectors (anthropogenic and natural) and originating from different geographical regions within and outside India during the northeast (NE) Indian winter monsoon (January-March). These studies are carried out through aerosol transport simulations in the general circulation (GCM) model of the Laboratoire de Météorologie Dynamique (LMD). The model estimates of aerosol single scattering albedo (SSA) show lower values (0.86-0.92) over the region north to 10°N comprising of the Indian subcontinent, Bay of Bengal, and parts of the Arabian Sea compared to the region south to 10°N where the estimated SSA values lie in the range 0.94-0.98. The model estimated SSA is consistent with the SSA values inferred through measurements on various platforms. Aerosols of anthropogenic origin reduce the incoming solar radiation at the surface by a factor of 10-20 times the reduction due to natural aerosols. At the top-of-atmosphere (TOA), aerosols from biofuel use cause positive forcing compared to the negative forcing from fossil fuel and natural sources in correspondence with the distribution of SSA which is estimated to be the lowest (0.7-0.78) from biofuel combustion emissions. Aerosols originating from India and Africa-west Asia lead to the reduction in surface radiation (-3 to -8 W m -2) by 40-60% of the total reduction in surface radiation due to all aerosols over the Indian subcontinent and adjoining ocean. Aerosols originating from India and Africa-west Asia also lead to positive radiative effects at TOA over the Arabian Sea, central India (CNI), with the highest positive radiative effects over the Bay of Bengal and cause either negative or positive effects over the Indo-Gangetic plain (IGP).

  14. Image Quality and Radiation Dose for Prospectively Triggered Coronary CT Angiography: 128-Slice Single-Source CT versus First-Generation 64-Slice Dual-Source CT

    Science.gov (United States)

    Gu, Jin; Shi, He-Shui; Han, Ping; Yu, Jie; Ma, Gui-Na; Wu, Sheng

    2016-10-01

    This study sought to compare the image quality and radiation dose of coronary computed tomography angiography (CCTA) from prospectively triggered 128-slice CT (128-MSCT) versus dual-source 64-slice CT (DSCT). The study was approved by the Medical Ethics Committee at Tongji Medical College of Huazhong University of Science and Technology. Eighty consecutive patients with stable heart rates lower than 70 bpm were enrolled. Forty patients were scanned with 128-MSCT, and the other 40 patients were scanned with DSCT. Two radiologists independently assessed the image quality in segments (diameter >1 mm) according to a three-point scale (1: excellent; 2: moderate; 3: insufficient). The CCTA radiation dose was calculated. Eighty patients with 526 segments in the 128-MSCT group and 544 segments in the DSCT group were evaluated. The image quality 1, 2 and 3 scores were 91.6%, 6.9% and 1.5%, respectively, for the 128-MSCT group and 97.6%, 1.7% and 0.7%, respectively, for the DSCT group, and there was a statistically significant inter-group difference (P ≤ 0.001). The effective doses were 3.0 mSv in the 128-MSCT group and 4.5 mSv in the DSCT group (P ≤ 0.001). Compared with DSCT, CCTA with prospectively triggered 128-MSCT had adequate image quality and a 33.3% lower radiation dose.

  15. Thomson scattering laser-electron X-ray source for reduction of patient radiation dose in interventional coronary angiography

    Science.gov (United States)

    Artyukov, I. A.; Dyachkov, N. V.; Feshchenko, R. M.; Polunina, A. V.; Popov, N. L.; Shvedunov, V. I.; Vinogradov, A. V.

    2017-05-01

    It was medical applications that stimulated F. Carrol in the early 1990s to start the research of on relativistic Thomson scattering X-ray sources, as a part of the infrastructure of the future society. The possibility to use such a source in interventional cardiology is discussed in this paper. The replacement of X-ray tube by relativistic Thomson scattering Xray source is predicted to lower the patient radiation dose by a factor of 3 while image quality remains the same. The required general characteristics of accelerator and laser units are found. They can be reached by existing technology. A semiempirical method for simulation of medical and technical parameters of interventional coronary angiography systems is suggested.

  16. Solar Radiation Model for Development and Control of Solar Energy Sources

    Directory of Open Access Journals (Sweden)

    Dominykas Vasarevičius

    2016-06-01

    Full Text Available The model of solar radiation, which takes into account direct, diffused and reflected components of solar energy, has been presented. Model is associated with geographical coordinates and local time of every day of the year. It is shown that using analytic equations for modelling the direct component, it is possible to adopt it for embedded systems with low computational power and use in solar tracking applications. Reflected and diffused components are especially useful in determining the performance of photovoltaic modules in certain location and surroundings. The statistical method for cloud layer simulation based on local meteorological data is offered. The presented method can’t be used for prediction of weather conditions but it provides patterns of solar radiation in time comparable to those measured with pyranometer. Cloud layer simulation together with total solar radiation model is a useful tool for development and analysis of maximum power point tracking controllers for PV modules.

  17. The Trilinear Hamiltonian: A Zero Dimensional Model of Hawking Radiation from a Quantized Source

    CERN Document Server

    Nation, P D

    2010-01-01

    We investigate a quantum parametric amplifier with dynamical pump mode, viewed as a zero-dimensional model of Hawking radiation from an evaporating black hole. The conditions are derived under which the spectrum of particles generated from vacuum fluctuations deviates from the thermal spectrum predicted for the conventional parametric amplifier. We find that significant deviations arise when the pump mode (black hole) has emitted nearly half of its initial energy into the signal (Hawking radiation) and idler (in-falling particle) modes. As a model of black hole dynamics, this finding lends support to the view that late-time Hawking radiation contains information about the quantum state of the black hole and is entangled with the black hole's quantum gravitational degrees of freedom.

  18. The trilinear Hamiltonian: a zero-dimensional model of Hawking radiation from a quantized source

    Energy Technology Data Exchange (ETDEWEB)

    Nation, Paul D; Blencowe, Miles P, E-mail: paul.d.nation@dartmouth.ed [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

    2010-09-15

    We investigate a quantum parametric amplifier with dynamical pump mode, viewed as a zero-dimensional model of Hawking radiation from an evaporating black hole. We derive the conditions under which the spectrum of particles generated from vacuum fluctuations deviates from the thermal spectrum predicted for the conventional parametric amplifier. We find that significant deviations arise when the pump mode (black hole) has emitted nearly half of its initial energy into the signal (Hawking radiation) and idler (in-falling particle) modes. As a model of black hole dynamics, this finding lends support to the view that late-time Hawking radiation contains information about the quantum state of the black hole and is entangled with the black hole's quantum gravitational degrees of freedom.

  19. Radiative neutron capture as a counting technique at pulsed spallation neutron sources: a review of current progress

    Science.gov (United States)

    Schooneveld, E. M.; Pietropaolo, A.; Andreani, C.; Perelli Cippo, E.; Rhodes, N. J.; Senesi, R.; Tardocchi, M.; Gorini, G.

    2016-09-01

    Neutron scattering techniques are attracting an increasing interest from scientists in various research fields, ranging from physics and chemistry to biology and archaeometry. The success of these neutron scattering applications is stimulated by the development of higher performance instrumentation. The development of new techniques and concepts, including radiative capture based neutron detection, is therefore a key issue to be addressed. Radiative capture based neutron detectors utilize the emission of prompt gamma rays after neutron absorption in a suitable isotope and the detection of those gammas by a photon counter. They can be used as simple counters in the thermal region and (simultaneously) as energy selector and counters for neutrons in the eV energy region. Several years of extensive development have made eV neutron spectrometers operating in the so-called resonance detector spectrometer (RDS) configuration outperform their conventional counterparts. In fact, the VESUVIO spectrometer, a flagship instrument at ISIS serving a continuous user programme for eV inelastic neutron spectroscopy measurements, is operating in the RDS configuration since 2007. In this review, we discuss the physical mechanism underlying the RDS configuration and the development of associated instrumentation. A few successful neutron scattering experiments that utilize the radiative capture counting techniques will be presented together with the potential of this technique for thermal neutron diffraction measurements. We also outline possible improvements and future perspectives for radiative capture based neutron detectors in neutron scattering application at pulsed neutron sources.

  20. HELIOS: An Open-Source, GPU-Accelerated Radiative Transfer Code For Self-Consistent Exoplanetary Atmospheres

    CERN Document Server

    Malik, Matej; Mendonça, João M; Grimm, Simon L; Lavie, Baptiste; Kitzmann, Daniel; Tsai, Shang-Min; Burrows, Adam; Kreidberg, Laura; Bedell, Megan; Bean, Jacob L; Stevenson, Kevin B; Heng, Kevin

    2016-01-01

    We present the open-source radiative transfer code named HELIOS, which is constructed for studying exoplanetary atmospheres. In its initial version, the model atmospheres of HELIOS are one-dimensional and plane-parallel, and the equation of radiative transfer is solved in the two-stream approximation with non-isotropic scattering. The opacities are computed with the opacity calculator HELIOS-K and converted to k-distribution tables by weighing the molecular abundances with analytical chemistry formulae. We validate HELIOS by comparing a model of GJ 1214b to that computed using COOLTLUSTY and from the work of Miller-Ricci & Fortney, and by performing several tests, where we find: model atmospheres with single-temperature layers struggle to converge to radiative equilibrium; k-distribution tables constructed with 1-10% in the synthetic spectra; and a diffusivity factor of 2 approximates well the exact radiative transfer solution in the limit of pure absorption. We construct "null-hypothesis" models (chemic...

  1. Oscillation photography of radiation-sensitive crystals using a synchrotron source

    Energy Technology Data Exchange (ETDEWEB)

    Rossmann, M.G.; Erickson, J.W. (Purdue Univ., Lafayette, IN (USA). Dept. of Biological Sciences)

    1983-12-01

    A method is described to determine the accurate setting of a crystal placed in an unknown orientation on an oscillation camera. This avoids time-consuming setting operations during which the crystal is subject to continuous radiation damage initiated by the first setting photograph. It also ensures maximal use of synchrotron radiation time as there is no need for any prior setting and developing periods. The method is dependent on measuring the lengths and orientations of the major axes of the ellipses on two, preferably approximately orthogonal, 'still' photographs. The method is applied to five different rhinovirus (common cold) crystals.

  2. Specific contributions of the Dutch progamme ``RAS`` towards accelerator-based transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Abrahams, K.; Franken, W.M.P.; Bultman, J.H.; Heil, J.A.; Koning, A.J.

    1994-09-01

    Accelerator-based transmutation is being studied by ECN within its general nuclear waste transmutation programme RAS. In this paper the following contributions are presented: (1) Evaluation of cross sections at intermediate energies, within an international frame given by NEA, (2) Cell calculations on the equilibration of transuranium actinides in thermal molten-salt transmuters, (3) Irradiation facilities at the European research reactor HFR in Petten, which have been constructed with the purpose to demonstrate and investigate the transmutation of waste in a high neutron flux, (4) Studies of accelerator-based neutron generating systems to transmute neptunium and technetium, (5) Comparison of several systems on the basis of criteria for successful nuclear waste-management. (orig.).

  3. Studies of industrial emissions by accelerator-based techniques: A review of applications at CEDAD

    OpenAIRE

    Calcagnile L.; Quarta G.

    2012-01-01

    Different research activities are in progress at the Centre for Dating and Diagnostics (CEDAD), University of Salento, in the field of environmental monitoring by exploiting the potentialities given by the different experimental beam lines implemented on the 3 MV Tande-tron accelerator and dedicated to AMS (Accelerator Mass Spectrome-try) radiocarbon dating and IB A (Ion Beam Analysis). An overview of these activities is presented by showing how accelerator-based analytical techniques can be ...

  4. Treatment planning capability assessment of a beam shaping assembly for accelerator-based BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, M.S., E-mail: herrera@tandar.cnea.gov.ar [Comision Nacional de Energia Atomica, CNEA, Av. Gral. Paz 1499, San Martin (Argentina)] [Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET, Av. Rivadavia 191, Buenos Aires (Argentina)] [Universidad Nacional de San Martin, UNSAM, Av. 25 de Mayo y Francia Buenos Aires (Argentina); Gonzalez, S.J. [Comision Nacional de Energia Atomica, CNEA, Av. Gral. Paz 1499, San Martin (Argentina)] [Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET, Av. Rivadavia 191, Buenos Aires (Argentina); Burlon, A.A. [Comision Nacional de Energia Atomica, CNEA, Av. Gral. Paz 1499, San Martin (Argentina)] [Universidad Nacional de San Martin, UNSAM, Av. 25 de Mayo y Francia Buenos Aires (Argentina); Minsky, D.M.; Kreiner, A.J. [Comision Nacional de Energia Atomica, CNEA, Av. Gral. Paz 1499, San Martin (Argentina)] [Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET, Av. Rivadavia 191, Buenos Aires (Argentina)] [Universidad Nacional de San Martin, UNSAM, Av. 25 de Mayo y Francia Buenos Aires (Argentina)

    2011-12-15

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT) a theoretical study was performed to assess the treatment planning capability of different configurations of an optimized beam shaping assembly for such a facility. In particular this study aims at evaluating treatment plans for a clinical case of Glioblastoma.

  5. Characterization of radiated electromagnetic fields using equivalent sources - Application to the EMC of power printed circuit boards

    Science.gov (United States)

    Beghou, Lotfi; Pichon, Lionel; Costa, François

    2009-01-01

    This article presents an original methodology to characterize electromagnetic disturbances radiated from power electronic devices. The method is based on the substitution of the power device by an equivalent set of elemental dipoles (electric and magnetic dipoles). The set of dipoles radiates the same near-field. The dipoles are determined from a near field cartography of the fields obtained with a measurement bench. The dipoles parameters are determined by solving an inverse problem using a genetic algorithm. The efficiency of the approach is demonstrated on an academic DC-DC converter. Finally some results about the chopper are presented. The methodology has two advantages: first it allows one to define some threshold limitations for electromagnetic fields on the surroundings and secondly it gives the location of the real source distribution. To cite this article: L. Beghou et al., C. R. Physique 10 (2009).

  6. A general analytical expression for the radiation source function of emitting and scattering media within the matrix operator method

    Science.gov (United States)

    Liu, Quanhua; Simmer, C.; Ruprecht, E.

    1991-05-01

    An analytical expression has been derived for the radiation source function for a thermally emitting and scattering medium within the Matrix-Operator-Method (MOM). The final formulation is equivalent to the one found by Aronson and Yarmush (1966), who applied the transfer matrix to gamma-ray and neutron penetration and to transport problems in slab geometry. For the thermal infrared case, the general analytical expression reduces to a simple formula, which depends only on the zenith angle. The formula is incorporated in the MOM together with analytical expressions of the transmission and reflection operators following Liu (1990). With the aid of these formulations, expressions are derived as parameterizations of the scattering effects of clouds in nonscattering radiative transfer models by a modification of the emissivity and transmittance of clouds. The accuracy is better than 0.5 percent in the 11.5 micron window region for clouds of arbitrary optical depths.

  7. R&D Toward a Compact High-Brilliance X-Ray Source Based on Channeling Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Piot, P.; /Fermilab /Northern Illinois U.; Brau, C.A.; Choi, B.K.; Gabella, W.E.; Jarvis, J.D.; Mendenhall, M.H.; /Vanderbilt U.; Lewellen, J.W.; /Naval Postgraduate School; Mihalcea, D.; /Northern Illinois U.

    2012-08-01

    X-rays have been valuable to a large number of fields including Science, Medicine, and Security. Yet, the availability of a compact high-spectral brilliance X-ray sources is limited. A technique to produce X-rays with spectral brilliance B {approx} 10{sup 12} photons.(mm-mrd){sup -2}.(0.1% BW){sup -1} .s{sup -1} is discussed. The method is based on the generation and acceleration of a low-emittance field-emitted electron bunches. The bunches are then focused on a diamond crystal thereby producing channeling radiation. In this paper, after presenting the overarching concept, we discuss the generation, acceleration and transport of the low-emittance bunches with parameters consistent with the production of high-brilliance X-rays through channeling radiation. We especially consider the example of the Advanced Superconducting Test Accelerator (ASTA) currently in construction at Fermilab where a proof-of-principle experiment is in preparation.

  8. Asymmetric lateral coherence of betatron radiation emitted in laser-driven light sources

    Science.gov (United States)

    Paroli, B.; Chiadroni, E.; Ferrario, M.; Petrillo, V.; Potenza, M. A. C.; Rossi, A. R.; Serafini, L.; Shpakov, V.

    2015-08-01

    We show that the radiation emitted by betatron oscillations of a high-energy electron beam undergoing wake-field acceleration is endowed with peculiar coherence properties which deliver quantitative information about the electron trajectories. Such results are achieved by means of accurate numerical simulations and a simple geometrical model gives a clear physical interpretation.

  9. Fears and misperceptions of radiation therapy: sources and impact on decision-making and anxiety.

    Science.gov (United States)

    Gillan, Caitlin; Abrams, Daniel; Harnett, Nicole; Wiljer, David; Catton, Pamela

    2014-06-01

    Recent media attention about radiation has led to heightened public awareness and concern about radiation therapy (RT). An understanding of concerns and their potential role in patient decision-making can inform education efforts. A multiphase needs assessment survey was designed to ascertain broad public perceptions of radiation (phase I) and the more in-depth cancer patient perceptions of RT (phase II). One hundred forty-six phase I and 111 phase II surveys were completed. Data suggested a prevalence of negative connotations of the word "radiation," often associated with information from the media or secondhand experience. Side effects during and after RT were reported as concerns, including misperceptions about becoming radioactive and impact on fertility. Rankings of quality and safety perceptions suggested confidence in staff training and equipment, though concerns regarding overdoses and protection of healthy tissue were higher amongst those who refused RT. In deciding whether or not to undergo RT, high value was placed on the reputation of the cancer centre and the expected effectiveness of RT. The importance of understanding RT was more highly regarded by those who underwent RT than those who refused it. Perceptions of RT should thus be addressed amongst those in a position to consider RT, to maximize RT utilization where appropriate.

  10. Use of gamma radiation with cobalt 60 source in the disinfection of documentary collections; Uso da radiacao gamma com fonte de cobalto 60 na desinfestacao de acervos documentais

    Energy Technology Data Exchange (ETDEWEB)

    Franca, Conceicao Linda de; Barboza, Kleumanery de Melo

    2011-07-01

    This article aims to conduct a comparative study between disinfection methods (anoxia and freezing) of documentary collections and the application of gamma radiation, with cobalt 60 source, by analyzing the pros and cons of each methods. This study is part of research developed by the authors that study the effect of radiation on materials

  11. Personnel dose assessment due to the normal operations with the artificial radiation sources according to the data from the unified system of individual dose control (USIDC

    Directory of Open Access Journals (Sweden)

    Yu. I. Stepkin

    2016-01-01

    Full Text Available The aim of the study was personnel dose assessment due to the normal operations with the artificial radiation sources. The article is based on the data from the Unified System of Individual Dose Control and Voronezh Region’s radiation-hygienic passport. The data from No.1-DOZ “Information on personnel exposure doses under normal operation of technogenic ionizing radiation sources” and over a period of 2006-2010 years were analyzed. In 2006-2015, the number of organizations, which submitted form No.1-DOZ “Information on personnel exposure doses under normal operation of technogenic ionizing radiation sources”, increased from 175 to 229. In amount of the radiation facilities, Novovoronezh Nuclear Power Plant is the first. Novovoronezh NPP has 1512 sources, which amounts to 51,9% from all sources in Voronezh Region (2915. Health care facilities have 869 radiation sources or 29,8%. X-ray machines are the main part of these sources (844 health care facilities or 97,1% of all medical sources. Industrial sources occupy third place with 305 facilities or 10,5% of all considered sources. In 2015, according to the data from Voronezh Region’s radiation-hygienic passport, the number of “A” group personnel were 4237, the number of “B” group personnel were 2341. The average individual dose for personnel was over the range from 0.66 to 2.02 mSv. Collective dose was from 4.16 to 11.79 man-sieverts per year. The increase of number of the radiation sources has attended with the decrease of individual and collective doses. The most likely it is related to using the modern facilities. In 2015, the maximum value of the average individual dose of “A” group personnel was registered in Voronezh regional hospital (6.17 mSv y–1. There are medical facilities with unsealed and sealed sources in this hospital. In 2006-2015, the average individual doses of personnel of all radiation facilities that use radiation sources in Voronezh

  12. Shielding design of a treatment room for an accelerator-based epithermal neutron irradiation facility for BNCT.

    Science.gov (United States)

    Evans, J F; Blue, T E

    1996-11-01

    Protecting the facility personnel and the general public from radiation exposure is a primary safety concern of an accelerator-based epithermal neutron irradiation facility. This work makes an attempt at answering the questions "How much?" and "What kind?" of shielding will meet the occupational limits of such a facility. Shielding effectiveness is compared for ordinary and barytes concretes in combination with and without borated polyethylene. A calculational model was developed of a treatment room , patient "scatterer," and the epithermal neutron beam. The Monte Carlo code, MCNP, was used to compute the total effective dose equivalent rates at specific points of interest outside of the treatment room. A conservative occupational effective dose rate limit of 0.01 mSv h-1 was the guideline for this study. Conservative Monte Carlo calculations show that constructing the treatment room walls with 1.5 m of ordinary concrete, 1.2 m of barytes concrete, 1.0 m of ordinary concrete preceded by 10 cm of 5% boron-polyethylene, or 0.8 m of barytes concrete preceded by 10 cm of 5% boron-polyethylene will adequately protect facility personnel.

  13. HELIOS: An Open-source, GPU-accelerated Radiative Transfer Code for Self-consistent Exoplanetary Atmospheres

    Science.gov (United States)

    Malik, Matej; Grosheintz, Luc; Mendonça, João M.; Grimm, Simon L.; Lavie, Baptiste; Kitzmann, Daniel; Tsai, Shang-Min; Burrows, Adam; Kreidberg, Laura; Bedell, Megan; Bean, Jacob L.; Stevenson, Kevin B.; Heng, Kevin

    2017-02-01

    We present the open-source radiative transfer code named HELIOS, which is constructed for studying exoplanetary atmospheres. In its initial version, the model atmospheres of HELIOS are one-dimensional and plane-parallel, and the equation of radiative transfer is solved in the two-stream approximation with nonisotropic scattering. A small set of the main infrared absorbers is employed, computed with the opacity calculator HELIOS-K and combined using a correlated-k approximation. The molecular abundances originate from validated analytical formulae for equilibrium chemistry. We compare HELIOS with the work of Miller-Ricci & Fortney using a model of GJ 1214b, and perform several tests, where we find: model atmospheres with single-temperature layers struggle to converge to radiative equilibrium; k-distribution tables constructed with ≳ 0.01 cm-1 resolution in the opacity function (≲ {10}3 points per wavenumber bin) may result in errors ≳ 1%-10% in the synthetic spectra; and a diffusivity factor of 2 approximates well the exact radiative transfer solution in the limit of pure absorption. We construct “null-hypothesis” models (chemical equilibrium, radiative equilibrium, and solar elemental abundances) for six hot Jupiters. We find that the dayside emission spectra of HD 189733b and WASP-43b are consistent with the null hypothesis, while the latter consistently underpredicts the observed fluxes of WASP-8b, WASP-12b, WASP-14b, and WASP-33b. We demonstrate that our results are somewhat insensitive to the choice of stellar models (blackbody, Kurucz, or PHOENIX) and metallicity, but are strongly affected by higher carbon-to-oxygen ratios. The code is publicly available as part of the Exoclimes Simulation Platform (exoclime.net).

  14. 78 FR 21567 - Installation of Radiation Alarms for Rooms Housing Neutron Sources

    Science.gov (United States)

    2013-04-11

    ... Materials and Environmental Management Programs, U.S. Nuclear Regulatory Commission, Washington, DC 20555... and spallation sources. Neutron sources are used in diverse applications in areas of physics... for on-the-spot analysis, and to detect ground water movement for environmental surveys. Neutron...

  15. Multispecies Outcomes of Sympatric Speciation after Admixture with the Source Population in Two Radiations of Nicaraguan Crater Lake Cichlids.

    Science.gov (United States)

    Kautt, Andreas F; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-06-01

    The formation of species in the absence of geographic barriers (i.e. sympatric speciation) remains one of the most controversial topics in evolutionary biology. While theoretical models have shown that this most extreme case of primary divergence-with-gene-flow is possible, only a handful of accepted empirical examples exist. And even for the most convincing examples uncertainties remain; complex histories of isolation and secondary contact can make species falsely appear to have originated by sympatric speciation. This alternative scenario is notoriously difficult to rule out. Midas cichlids inhabiting small and remote crater lakes in Nicaragua are traditionally considered to be one of the best examples of sympatric speciation and lend themselves to test the different evolutionary scenarios that could lead to apparent sympatric speciation since the system is relatively small and the source populations known. Here we reconstruct the evolutionary history of two small-scale radiations of Midas cichlids inhabiting crater lakes Apoyo and Xiloá through a comprehensive genomic data set. We find no signs of differential admixture of any of the sympatric species in the respective radiations. Together with coalescent simulations of different demographic models our results support a scenario of speciation that was initiated in sympatry and does not result from secondary contact of already partly diverged populations. Furthermore, several species seem to have diverged simultaneously, making Midas cichlids an empirical example of multispecies outcomes of sympatric speciation. Importantly, however, the demographic models strongly support an admixture event from the source population into both crater lakes shortly before the onset of the radiations within the lakes. This opens the possibility that the formation of reproductive barriers involved in sympatric speciation was facilitated by genetic variants that evolved in a period of isolation between the initial founding

  16. Dynamic Source Inversion of an Intraslab Earthquake: a Slow and Inefficient Rupture with Large Stress Drop and Radiated Energy

    Science.gov (United States)

    Cruz-Atienza, V. M.; Diaz-Mojica, J.; Madariaga, R. I.; Singh, S. K.; Tago Pacheco, J.; Iglesias, A.

    2014-12-01

    We introduce a method for imaging the earthquake source dynamics through the inversion of ground motion records based on a parallel genetic algorithm. The source model follows an elliptical patch approach and uses the staggered-grid split-node method to model the earthquake dynamics. A statistical analysis is used to estimate uncertainties in both inverted and derived source parameters. Synthetic inversion tests reveal that the rupture speed (Vr), the rupture area and the stress drop (Δτ) are determined within an error of ~30%, ~12% and ~10%, respectively. In contrast, derived parameters such as the radiated energy (Er), the radiation efficiency (η) and the fracture energy (G) have larger uncertainties, around ~70%, ~40% and ~25%, respectively. We applied the method to the Mw6.5 intermediate-depth (62 km) normal-faulting earthquake of December 11, 2011 in Guerrero, Mexico (Diaz-Mojica et al., JGR, 2014). Inferred values of Δτ = 29.2±6.2 MPa and η = 0.26±0.1 are significantly higher and lower, respectively, than those of typical subduction thrust events. Fracture energy is large, so that more than 73% of the available potential energy for the dynamic process of faulting was deposited in the focal region (i.e., G = (14.4±3.5)x1014J), producing a slow rupture process (Vr/Vs = 0.47±0.09) despite the relatively-high energy radiation (Er = (0.54±0.31)x1015 J) and energy-moment ratio (Er/M0 = 5.7x10-5). It is interesting to point out that such a slow and inefficient rupture along with the large stress drop in a small focal region are features also observed in the 1994 deep Bolivian earthquake.

  17. Development of radiosotopes and radiation sources; developments of activity measurement and evaluation technique of homemade radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Han Yull; Choi, Yun Ho; Byun, Jong In; Lee, Ju Hee; Lee, Sun A. [Mokwon University, Taejeon (Korea)

    2002-04-01

    In this study, we report on the development of the production technique of radioactive sources suitable to precisely calibrate the energy and detection efficiency of the semiconductor gamma detectors. We developed totally 4 calibration sources, {sup 137}Cs and {sup 60}Co producted from HANARO reactor at Korea Atomic Energy Research Institute and {sup 152}Eu, mixed source {sup 154+155}Eu. In order to investigate the special qualities of these calibration sources, the mass absorption coefficients, due to the thickness of source container, were systematically measured. And the absolute detection efficiency curve of the used Ge detector was obtained by using the standardized source {sup 152}Eu. The activity of a mixed source {sup 154+155}Eu is determined with assistant of the resulted detection efficiency curve. As a result, the detection efficiency curve can be determined overall the energy regions from 0 keV to 2000 keV by using this mixed calibration source. The activity of each {sup 137}Cs, {sup 60}Co and {sup 152}Eu is obtained and the uncertainty of each activity is evaluated by root square sums of each uncertainty component arising from the decay parameters, and from the counting statistics, and from the used standard source, and from the fraction of losses to pass out the source and from the sample impurities. Total error was found to be 1.2 % above the ranges of the knee point 150 keV and to be 4.5 % below the regions of the point. 8 refs., 8 figs., 7 tabs. (Author)

  18. Photoelectron Emission from Metal Surfaces Induced by Radiation Emitted by a 14 GHz Electron Cyclotron Resonance Ion Source

    CERN Document Server

    Laulainen, Janne; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli

    2015-01-01

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10 % of the estimated total electron losses from the plasma.

  19. Photoelectron emission from metal surfaces induced by radiation emitted by a 14 GHz electron cyclotron resonance ion source

    Science.gov (United States)

    Laulainen, Janne; Kalvas, Taneli; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli

    2016-02-01

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10% of the estimated total electron losses from the plasma.

  20. Dense plasma focus PACO as a hard X-ray emitter: a study on the radiation source

    OpenAIRE

    Supán, L.; Guichón, S.; Milanese, Maria Magdalena; Niedbalski, Jorge Julio; Moroso, Roberto Luis; Acuña, H.; Malamud, Florencia

    2016-01-01

    The radiation in the X-ray range detected outside the vacuum chamber of the dense plasma focus (DPF) PACO, are produced on the anode zone. The zone of emission is studied in a shot-to-shot analysis, using pure deuterium as filling gas. We present a diagnostic method to determine the place and size of the hard X-ray source by image analysis of high density radiography plates. Fil: Supán, L.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Insti...

  1. Photoelectron emission from metal surfaces induced by radiation emitted by a 14 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Laulainen, Janne, E-mail: janne.p.laulainen@student.jyu.fi; Kalvas, Taneli; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli [Department of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla (Finland)

    2016-02-15

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10% of the estimated total electron losses from the plasma.

  2. Terahertz radiation source using a high-power industrial electron linear accelerator

    Indian Academy of Sciences (India)

    YASHVIR KALKAL; VINIT KUMAR

    2017-04-01

    High-power $(\\sim 100 kW)$ 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, 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 linac. We have performed calculation of spontaneous emission in the undulator to show that for typical parameters, continuous terahertz radiation having power of the order of $\\mu$W can be produced, which may be useful for many scientific applications such as multispectral imaging of biological samples, chemical samples etc.

  3. Terahertz radiation source using a high-power industrial electron linear accelerator

    Science.gov (United States)

    Kalkal, Yashvir; Kumar, Vinit

    2017-04-01

    High-power (˜ 100 kW) 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, 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 linac. We have performed calculation of spontaneous emission in the undulator to show that for typical parameters, continuous terahertz radiation having power of the order of μW can be produced, which may be useful for many scientific applications such as multispectral imaging of biological samples, chemical samples etc.

  4. The Trilinear Hamiltonian: A Zero Dimensional Model of Hawking Radiation from a Quantized Source

    OpenAIRE

    Nation, P. D.; Blencowe, M. P.

    2010-01-01

    We investigate a quantum parametric amplifier with dynamical pump mode, viewed as a zero-dimensional model of Hawking radiation from an evaporating black hole. The conditions are derived under which the spectrum of particles generated from vacuum fluctuations deviates from the thermal spectrum predicted for the conventional parametric amplifier. We find that significant deviations arise when the pump mode (black hole) has emitted nearly half of its initial energy into the signal (Hawking radi...

  5. A Fast Field Scheme for the Parametric Sound Radiation from Rectangular Aperture Source

    Institute of Scientific and Technical Information of China (English)

    杨军; 沙侃; 颜允圣; 田静

    2004-01-01

    A virtual complex source approach has been developed to calculate numerically the ultrasound field generated by a rectangular planar source with high efficiency. The sound field can be treated as the resultant sound pressure from a set of complex virtual sources located at a complex distance, and then by exploiting the integrability of Gaussian function, a substantial analytical reduction to single integral is derived for the second-order field of the sum-, difference-frequency and second harmonic components. The validity of this fast field scheme is confirmed by comparison of numerical results and the experimental data published previously.

  6. Quantum collapse as a source of the seeds of cosmic structure during the radiation era

    Science.gov (United States)

    León, Gabriel; Landau, Susana J.; Piccirilli, María Pía

    2014-10-01

    The emergence of the seeds of cosmic structure, from a perfect isotropic and homogeneous Universe, has not been clearly explained by the standard version of inflationary models as the dynamics involved preserve the homogeneity and isotropy at all times. A proposal that attempts to deal with this problem, by introducing "the self-induced collapse hypothesis," has been introduced by D. Sudarsky and collaborators in previous papers. In all these works, the collapse of the wave function of the inflaton mode is restricted to occur during the inflationary period. In this paper, we analyze the possibility that the collapse happens during the radiation era. A viable model can be constructed under the condition that the inflaton field variable must be affected by the collapse while the momentum variable can or cannot be affected. Another condition to be fulfilled is that the time of collapse must be independent of k . However, when comparing with recent observational data, the predictions of the model cannot be distinguished from the ones provided by the standard inflationary scenario. The main reason for this arises from the requirement that primordial power spectrum obtained for the radiation era matches the amplitude of scalar fluctuations consistent with the latest cosmic microwave background observations. This latter constraint results in a limit on the possible times of collapse and ensures that the contribution of the inflaton field to the energy-momentum tensor is negligible compared to the contribution of the radiation fields.

  7. Radiation protection for an intraoperative X-ray source compared to C-arm fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Frank; Clausen, Sven; Jahnke, Anika; Steil, Volker; Wenz, Frederik [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Radiation Oncology; Bludau, Frederic; Obertacke, Udo [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Trauma Surgery; Suetterlin, Marc [Heidelberg Univ., University Medical Center Mannheim (Germany). Dept. of Obstetrics and Gynaecology

    2014-10-01

    Background: Intraoperative radiotherapy (IORT) using the INTRABEAM {sup registered} system promises a flexible use regarding radiation protection compared to other approaches such as electron treatment or HDR brachytherapy with {sup 192}Ir or {sup 60}Co. In this study we compared dose rate measurements of breast- and Kypho-IORT with C-arm fluoroscopy which is needed to estimate radiation protection areas. Materials and Methods: C-arm fluoroscopy, breast- and Kypho-IORTs were performed using phantoms (silicon breast or bucket of water). Dose rates were measured at the phantom's surface, at 30 cm, 100 cm and 200 cm distance. Those measurements were confirmed during 10 Kypho-IORT and 10 breast-IORT patient treatments. Results: The measured dose rates were in the same magnitude for all three paradigms and ranges from 20 μSv/h during a simulated breast-IORT at two meter distance up to 64 mSv/h directly at the surface of a simulated Kypho-IORT. Those measurements result in a circle of controlled area (yearly doses > 6 mSv) for each paradigm of about 4 m ± 2 m. Discussion/Conclusions: All three paradigms show comparable dose rates which implies that the radiation protection is straight forward and confirms the flexible use of the INTRABEAM {sup registered} system. (orig.)

  8. Spatial and temporal characteristics of VHF radiation source produced by lightning in supercell thunderstorms

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yijun; MENG Qing; P. R. Krehbiel; LIU Xinsheng; ZHOU Xiuji

    2004-01-01

    The three-dimensional temporal and spatial characteristics of VHF radiation events produced by lightning discharges in three supercell thunderstorms have been analyzed based on the data measured by the lightning mapping array system with high time and space resolution. The results indicate that lightning hole (lighting free region) with about 5-6 km in diameter or lighting ring (annular lighting free region) is associated with the strong updraft in thunderstorm. The lasting time of lightning holes is either short or long, being about 20 min in a tornado-producing thunderstorm. The lightning holes appear before the occurrence of tornado. The lightning hole is the most obvious during the occurrence of tornado and some self-existent lighting radiation events appear at a height of 15-16 km. The lightning channels of inter-cloud (IC) lightning discharge exhibit clockwise rotary structures and do not have clear bilevel structures in the vicinity of the tornado. The lightning holes are corresponding to the strong updraft region. The temporal and spatial distribution of lightning radiation events reveals the structure of strong updraft in supercell thunderstorms.Positive cloud-to-ground (CG) lightning discharges dominate in these thunderstorms and the peak of positive CG lightning flash rate appears, with the maximum of 6 per minute, after or before the occurrence of tornado.

  9. Limit of detection of a fiber optics gyroscope using a super luminescent radiation source

    CERN Document Server

    Sandoval, G E

    2003-01-01

    The main objective of this work is to establish the dependence of characteristics of the fiber optics gyroscope (FOG) with respect to the parameters of the super luminescent emission source based on doped optical fiber with rare earth elements (Super luminescent Fiber Source, SFS), argument the pumping rate election of the SFS to obtain characteristics limits of the FOG sensibility. By using this type of emission source in the FOG is recommend to use the rate when the direction of the pumping signal coincide with the super luminescent signal. The most results are the proposition and argumentation of the SFS election as emission source to be use in the FOG of the phase type. Such a decision allow to increase the characteristics of the FOG sensibility in comparison with the use of luminescent source of semiconductors emission which are extensively used in the present time. The use of emission source of the SFS type allow to come closer to the threshold of the obtained sensibility limit (detection limit) which i...

  10. High-intensity sources of incoherent UV and VUV excimer radiation for low-temperature materials processing

    Science.gov (United States)

    Kogelschatz, U.; Esrom, H.; Zhang, J.-Y.; Boyd, I. W.

    2000-12-01

    The principles and properties of ultraviolet (UV) and vacuum ultraviolet (VUV) radiation generated by decaying excimer complexes are discussed. Excimer lamps offer high-intensity narrow-band radiation at various UV and VUV wavelengths and reach high efficiencies. They can provide high photon fluxes over extended areas. The use of excimers offers several advantages: excimers can be extremely efficient energy converters transforming electron kinetic energy into UV radiation. No self-absorption is observed in excimer systems. In most cases, excimer forming gas mixtures exhibit one dominant narrow emission band. Excimer systems can be pumped at extremely high power densities before saturation effects start to limit the spontaneous emission. Thus, extremely bright UV and VUV sources can be built. Different types of excimer lamps can be fabricated utilising, repetitively pulsed high power discharges, microwave discharges and dielectric-barrier discharges (silent discharges). For large-scale industrial applications dielectric-barrier discharges using fairly simple discharge configurations currently represent the most mature excimer lamp technology. Recent applications of excimer lamps include photo-deposition of large area or patterned thin metal films, of high- and low-dielectric constant insulating layers, photo-assisted low-temperature oxidation of Si, SiGe and Ge, UV curing, polymer etching and microstructuring of polymer surfaces. Applications investigated so far clearly demonstrate that low cost, high power excimer lamp systems can provide an interesting alternative to excimer lasers for industrial large-scale low-temperature materials processing.

  11. Repetitively pulsed UV radiation source based on a run-away electron preionised diffuse discharge in nitrogen

    Science.gov (United States)

    Baksht, E. Kh; Burachenko, A. G.; Lomaev, M. I.; Panchenko, A. N.; Tarasenko, V. F.

    2015-04-01

    An extended repetitively pulsed source of spontaneous UV radiation is fabricated, which may also be used for producing laser radiation. Voltage pulses with an incident wave amplitude of up to 30 kV, a half-amplitude duration of ~4 ns and a rise time of ~2.5 ns are applied to a gap with a nonuniform electric field. For an excitation region length of 35 cm and a nitrogen pressure of 30 - 760 Torr, a diffusive discharge up to a pulse repetition rate of 2 kHz is produced without using an additional system for gap preionisation. An investigation is made of the plasma of the run-away electron preionised diffuse discharge. Using a CCD camera it is found that the dense diffused plasma fills the gap in a time shorter than 1 ns. X-ray radiation is recorded from behind the foil anode throughout the pressure range under study; a supershort avalanche electron beam is recorded by the collector electrode at pressures below 100 Torr.

  12. Repetitively pulsed UV radiation source based on a run-away electron preionised diffuse discharge in nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Baksht, E Kh; Burachenko, A G; Lomaev, M I; Panchenko, A N; Tarasenko, V F [Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation)

    2015-04-30

    An extended repetitively pulsed source of spontaneous UV radiation is fabricated, which may also be used for producing laser radiation. Voltage pulses with an incident wave amplitude of up to 30 kV, a half-amplitude duration of ∼4 ns and a rise time of ∼2.5 ns are applied to a gap with a nonuniform electric field. For an excitation region length of 35 cm and a nitrogen pressure of 30 – 760 Torr, a diffusive discharge up to a pulse repetition rate of 2 kHz is produced without using an additional system for gap preionisation. An investigation is made of the plasma of the run-away electron preionised diffuse discharge. Using a CCD camera it is found that the dense diffused plasma fills the gap in a time shorter than 1 ns. X-ray radiation is recorded from behind the foil anode throughout the pressure range under study; a supershort avalanche electron beam is recorded by the collector electrode at pressures below 100 Torr. (laser applications and other topics in quantum electronics)

  13. Design considerations for a Space Station radiation shield for protection from both man-made and natural sources

    Science.gov (United States)

    Bolch, Wesley E.; Peddicord, K. Lee; Felsher, Harry; Smith, Simon

    1994-12-01

    This study was conducted to analyze scenarios involving the use of nuclear-power vehicles in the vicinity of a manned Space Station (SS) in low-earth-orbit (LEO) to quantify their radiological impact to the station crew. In limiting the radiant dose to crew members, mission planners may (1) shut the reactor down prior to reentry, (2) position the vehicle at a prescribed parking distance, and (3) deploy radiation shield about the shutdown reactor. The current report focuses on the third option in which point-kernel gamma-ray shielding calculations were performed for a variety of shield configurations for both nuclear electric propulsion (NEP) and nuclear thermal rocket (NTR) vehicles. For a returning NTR vehicle, calculations indicate that a 14.9 MT shield would be needed to limit the integrated crew exposure to no more than 0.05 Sv over a period of six months (25 percent of the allowable exposure to man-made radiation sources). During periods of low vehicular activity in LEO, the shield may be redeployed about the SS habitation module in order to decrease crew exposures to trapped proton radiations by approximately a factor of 10. The corresponding shield mass required for deployment at a returning NEP vehicle is 2.21 MT. Additional scenarios examined include the radioactivation of various metals as might be found in tools used in EVA activities.

  14. Radiation and Mass Transfer Effects on MHD Free Convective Dissipative Fluid in the Presence of Heat Source/Sink

    Directory of Open Access Journals (Sweden)

    S. Suneetha

    2011-01-01

    Full Text Available Thermal radiation effects on MHD flow past an impulsively started vertical plate in the presence of heat source/sink is investigated, by taking into account the heat due to viscous dissipation. The governing boundary layer equations of the flow field are solved by an implicit finite difference method of Crank-Nicholson type. A parametric study is performed to illustrate the influence of radiation parameter, magnetic parameter, Grashof number, Prandtl number, Eckert number on the velocity, temperature and concentration profiles. Also, the local and average skin-friction, Nusselt number and Sherwood number are presented graphically. The numerical results reveal that the radiation induces a rise in both the velocity and temperature, and a decrease in the concentration. Also with an increase in the heat absorption/generation parameter the velocity increases whereas the temperature decreases. The model finds applications in solar energy collection systems, geophysics and astrophysics, aero space and also in the design of high temperature chemical process systems.

  15. Low temperature plasmas created by photoionization of gases with intense radiation pulses from laser-produced plasma sources

    Science.gov (United States)

    Bartnik, A.; Pisarczyk, T.; Wachulak, P.; Chodukowski, T.; Fok, T.; Wegrzyński, Ł.; Kalinowska, Z.; Fiedorowicz, H.

    2016-12-01

    A comparative study of photoionized plasmas created by soft X-ray (SXR) and extreme ultraviolet (EUV) laser plasma sources was performed. The sources, employing high or low energy laser systems, utilized double-stream Xe/He gas-puff targets irradiated with laser pulses of different parameters. The SXR/EUV beams were used for irradiation of a gas stream, injected into a vacuum chamber synchronously with the radiation pulse. Photoionized plasmas produced this way in Ne gas emitted radiation in the SXR/EUV range. The corresponding spectra were dominated by emission lines originating from singly charged ions. Significant differences between spectra obtained in different experimental conditions concern specific transitions in Ne II ions. Creation of photoionized plasmas by SXR or EUV irradiation resulted in K-shell or L-shell emissions respectively. In case of the low energy system absorption spectra were measured additionally. In case of the high energy system, the electron density measurements were performed by laser interferometry, employing a femtosecond laser system. A maximum electron density reached the value of 2·1018cm-3. For the low energy system, a detection limit was too high for the interferometric measurements, thus only an upper estimation for electron density could be made.

  16. Technological yields of sources for radiation processing; Wydajnosci technologiczne zrodel do obrobki radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Zagorski, Z.P. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1993-12-31

    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.

  17. Optimal Neutron Source and Beam Shaping Assembly for Boron Neutron Capture Therapy

    CERN Document Server

    Vujic, J L; Greenspan, E; Guess, S; Karni, Y; Kastenber, W E; Kim, L; Leung, K N; Regev, D; Verbeke, J M; Waldron, W L; Zhu, Y

    2003-01-01

    There were three objectives to this project: (1) The development of the 2-D Swan code for the optimization of the nuclear design of facilities for medical applications of radiation, radiation shields, blankets of accelerator-driven systems, fusion facilities, etc. (2) Identification of the maximum beam quality that can be obtained for Boron Neutron Capture Therapy (BNCT) from different reactor-, and accelerator-based neutron sources. The optimal beam-shaping assembly (BSA) design for each neutron source was also to e obtained. (3) Feasibility assessment of a new neutron source for NCT and other medical and industrial applications. This source consists of a state-of-the-art proton or deuteron accelerator driving and inherently safe, proliferation resistant, small subcritical fission assembly.

  18. Optimal Neutron Source & Beam Shaping Assembly for Boron Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    J. Vujic; E. Greenspan; W.E. Kastenber; Y. Karni; D. Regev; J.M. Verbeke, K.N. Leung; D. Chivers; S. Guess; L. Kim; W. Waldron; Y. Zhu

    2003-04-30

    There were three objectives to this project: (1) The development of the 2-D Swan code for the optimization of the nuclear design of facilities for medical applications of radiation, radiation shields, blankets of accelerator-driven systems, fusion facilities, etc. (2) Identification of the maximum beam quality that can be obtained for Boron Neutron Capture Therapy (BNCT) from different reactor-, and accelerator-based neutron sources. The optimal beam-shaping assembly (BSA) design for each neutron source was also to e obtained. (3) Feasibility assessment of a new neutron source for NCT and other medical and industrial applications. This source consists of a state-of-the-art proton or deuteron accelerator driving and inherently safe, proliferation resistant, small subcritical fission assembly.

  19. Electric discharge in water as a source of UV radiation, ozone and hydrogen peroxide

    Science.gov (United States)

    Anpilov, A. M.; Barkhudarov, E. M.; Bark, Yu B.; Zadiraka, Yu V.; Christofi, M.; Kozlov, Yu N.; Kossyi, I. A.; Kop'ev, V. A.; Silakov, V. P.; Taktakishvili, M. I.; Temchin, S. M.

    2001-03-01

    Results are presented from investigations of multispark electric discharge in water excited along multielectrode metal-dielectric systems with gas supply into the interelectrode gaps. The intensity distribution of discharge radiation in the region covering the biologically active soft UV (190≤λ≤430 nm) has been determined and the absolute number of quanta in this wavelength interval has been measured. The potentiality of the slipping surface discharge in water for its disinfection is analysed. The energy expenditure for water cleansing is estimated to be as low as ~10-4 kWh l-1.

  20. Plasma radiation sources. Quasi-adiabatic theory and numerical modeling in the electro-diffusive approximation

    Science.gov (United States)

    Guillory, J. U.; Terry, R. E.

    1984-07-01

    This report describes work done under DNA Contract 001-79-C-0189 from February 1982 to June 1983, and some more recent work. Part 1 includes treatments of a simple zero-D implosion code, analytic but very approximate scaling laws for radiation, and a discussion of preliminary work on nonlinear field penetration of plasma. Part 2 contains a discussion of electrodiffusive 1D modeling of annular plasma implosions. The thermoelectrical field, its role in field penetrations, the nonlocal constraints required in field diffusion (and some arising from field diffusion), flux limits and the acceleration process for annular plasmas are discussed.

  1. Radiative properties of Bay of Bengal aerosols: Spatial distinctiveness and source impacts

    Science.gov (United States)

    Babu, S. Suresh; Gogoi, Mukunda M.; Kumar, V. H. Arun; Nair, Vijayakumar S.; Moorthy, K. Krishna

    2012-03-01

    Simultaneous and collocated measurements of spectrally resolved scattering and absorption coefficients and mass concentration of near-surface composite aerosols in the marine atmosphere over the Bay of Bengal (BOB), along with incoming shortwave (0.3-3 μm) global solar radiation and columnar spectral aerosol optical depths (AOD), were made on a research cruise during the winter phase of the Integrated Campaign for Aerosols, Gases and Radiation Budget (W-ICARB). The aerosol radiative properties revealed distinct spatial features associated with the contrasting outflows from Indo-Gangetic Plain (IGP) and East Asia. Both scattering and absorption coefficients depicted very high values (>200 and >15 Mm-1) over the northwestern and southeastern BOB and extremely low values (<50 and <10 Mm-1) over the central BOB. The mean value of the total scattering coefficient at 550 nm (˜123.7 ± 85.3 Mm-1) over the entire BOB during winter was higher than the mean values (˜94 ± 47 Mm-1) reported for the premonsoon season. While SSA at 550 nm showed very low values (<0.8) over a very large region in the central BOB and moderately low values over the southern BOB (˜0.85-0.9), the columnar AOD varied from the least values of ˜0.1 over the northeastern BOB to the highest values of ˜0.8 over the northwestern BOB. While significant cooling was observed at the top of the atmosphere and surface over the northwestern BOB, the atmospheric forcing was found to be significantly high (˜15 W m-2) over the southern BOB, where the aerosol radiative forcing efficiency (ARFE) at the surface was also found to be high. Examination of the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived fire count along with the advection pathways revealed a strong contribution from the emissions of biomass smoke from East Asia, which might be contributing to the enhanced aerosol induced warming over the southern BOB. However, the ARFE at the surface was low over the northwestern BOB, where the

  2. Radiation sources with planar wire arrays and planar foils for inertial confinement fusion and high energy density physics research

    Energy Technology Data Exchange (ETDEWEB)

    Kantsyrev, V. L.; Safronova, A. S.; Esaulov, A. A.; Shrestha, I.; Astanovitsky, A.; Osborne, G. C.; Shlyaptseva, V. V.; Weller, M. E.; Keim, S.; Stafford, A.; Cooper, M. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); Chuvatin, A. S. [Laboratorie de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau (France); Rudakov, L. I. [Icarus Research Inc., Bethesda, Maryland 20824 (United States); Velikovich, A. L. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-03-15

    This article reports on the joint success of two independent lines of research, each of them being a multi-year international effort. One of these is the development of innovative sources, such as planar wire arrays (PWAs). PWAs turned out to be a prolific radiator, which act mainly as a resistor, even though the physical mechanism of efficient magnetic energy conversion into radiation still remains unclear. We review the results of our extensive studies of PWAs. We also report the new results of the experimental comparison PWAs with planar foil liners (another promising alternative to wire array loads at multi-mega-ampere generators). Pioneered at UNR, the PWA Z-pinch loads have later been tested at the Sandia National Laboratories (SNL) on the Saturn generator, on GIT-12 machine in Russia, and on the QiangGuang-1 generator in China, always successfully. Another of these is the drastic improvement in energy efficiency of pulsed-power systems, which started in early 1980s with Zucker's experiments at Naval Research Laboratory (NRL). Successful continuation of this approach was the Load Current Multiplier (LCM) proposed by Chuvatin in collaboration with Rudakov and Weber from NRL. The 100 ns LCM was integrated into the Zebra generator, which almost doubled the plasma load current, from 0.9 to 1.7 MA. The two above-mentioned innovative approaches were used in combination to produce a new compact hohlraum radiation source for ICF, as jointly proposed by SNL and UNR [Jones et al., Phys. Rev. Lett. 104, 125001 (2010)]. The first successful proof-of-the-principle experimental implementation of new hohlraum concept at university-scale generator Zebra/LCM is demonstrated. A numerical simulation capability with VisRaD code (from PRISM Co.) established at UNR allowed for the study of hohlraum coupling physics and provides the possibility of optimization of a new hohlraum. Future studies are discussed.

  3. Radiation sources with planar wire arrays and planar foils for inertial confinement fusion and high energy density physics research

    Science.gov (United States)

    Kantsyrev, V. L.; Chuvatin, A. S.; Safronova, A. S.; Rudakov, L. I.; Esaulov, A. A.; Velikovich, A. L.; Shrestha, I.; Astanovitsky, A.; Osborne, G. C.; Shlyaptseva, V. V.; Weller, M. E.; Keim, S.; Stafford, A.; Cooper, M.

    2014-03-01

    This article reports on the joint success of two independent lines of research, each of them being a multi-year international effort. One of these is the development of innovative sources, such as planar wire arrays (PWAs). PWAs turned out to be a prolific radiator, which act mainly as a resistor, even though the physical mechanism of efficient magnetic energy conversion into radiation still remains unclear. We review the results of our extensive studies of PWAs. We also report the new results of the experimental comparison PWAs with planar foil liners (another promising alternative to wire array loads at multi-mega-ampere generators). Pioneered at UNR, the PWA Z-pinch loads have later been tested at the Sandia National Laboratories (SNL) on the Saturn generator, on GIT-12 machine in Russia, and on the QiangGuang-1 generator in China, always successfully. Another of these is the drastic improvement in energy efficiency of pulsed-power systems, which started in early 1980s with Zucker's experiments at Naval Research Laboratory (NRL). Successful continuation of this approach was the Load Current Multiplier (LCM) proposed by Chuvatin in collaboration with Rudakov and Weber from NRL. The 100 ns LCM was integrated into the Zebra generator, which almost doubled the plasma load current, from 0.9 to 1.7 MA. The two above-mentioned innovative approaches were used in combination to produce a new compact hohlraum radiation source for ICF, as jointly proposed by SNL and UNR [Jones et al., Phys. Rev. Lett. 104, 125001 (2010)]. The first successful proof-of-the-principle experimental implementation of new hohlraum concept at university-scale generator Zebra/LCM is demonstrated. A numerical simulation capability with VisRaD code (from PRISM Co.) established at UNR allowed for the study of hohlraum coupling physics and provides the possibility of optimization of a new hohlraum. Future studies are discussed.

  4. Radiation Detection Equipment (RDE) Comparative Evaluation Test Program. Volume 1. Point Source Measurements

    Science.gov (United States)

    1994-08-01

    OC W 1. AGINCY USE ONLY M.enm bika ) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED I 940801 I Technical 930201 - 930731 4. TITLE AND SUB`TITLE 5...unmoderaled source. 2/18/93 Detector: Ludlum Model 15 Positve radil alis 1000. of counts 9ma A Xakn~mrfli zab .02 Lim mromm 928 32.5 100 0.040 66.7 32.5...16100 16100 161 D- 16 Table D-48. Am(U) measurement data for "strong" shielded source. (page 7 of 7) Detctor. INF Stong Am(U) Afeswemenft-Ostector lim

  5. Plasma scattering measurement using a submillimeter wave gyrotron as a radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, I.; Idehara, T.; Itakura, Y.; Myodo, M. [Fukui Univ., Research Center for Development of Far-Infrared Region (Japan); Hori, T. [National Institute of Information and Communications Technology, Basic and Advanced Research Division, Nukui-Kita, Koganei (Japan); Hatae, T. [Japan Atomic Energy Research Institute, Mukoyama, Naka (Japan)

    2004-07-01

    Plasma scattering measurement is an effective technique to observe low frequency density fluctuations excited in plasma. The spatial and wave number resolutions and the S/N ratio of measurement depend on the wavelength range, the size and the intensity of a probe beam. A well-collimated, submillimeter wave beam is suitable for improving the spatial and wave number resolutions. Application of high frequency gyrotron is effective in improving the S/N ratio of the measurement because of its capacity to deliver high power. Unlike the molecular vapor lasers, the gyrotrons generate diverging beam of radiation with TE{sub mn} mode structure. It is therefore necessary to convert the output radiation into a Gaussian beam. A quasi-optical antenna is a suitable element for the conversion system under consideration since it is applicable to several TE{sub 0n} and TE{sub 1n} modes. In order to apply the gyrotron to plasma scattering measurement, we have stabilized the output (P = 110 W, f = 354 GHz) of gyrotron up to the level ({delta}P/P < 1 %, {delta}f< 10 kHz). The gyrotron output can be stabilized by decreasing the fluctuation of the cathode potential. (authors)

  6. General relativistic radiation hydrodynamics of accretion flows: II. Treating stiff source terms and exploring physical limitations

    CERN Document Server

    Roedig, Constanze; Alic, Daniela

    2012-01-01

    We present the implementation of an implicit-explicit (IMEX) Runge-Kutta numerical scheme for general relativistic hydrodynamics coupled to an optically thick radiation field in two existing GR-hydrodynamics codes. We argue that the necessity of such an improvement arises naturally in astrophysically relevant regimes where the optical thickness is high as the equations become stiff. By performing several 1D tests we verify the codes' new ability to deal with this stiffness and show consistency. Then, still in 1D, we compute a luminosity versus accretion rate diagram for the setup of spherical accretion onto a Schwarzschild black hole and find good agreement with previous work. Lastly, we revisit the supersonic Bondi Hoyle Lyttleton (BHL) accretion in 2D where we can now present simulations of realistic temperatures, down to T~10^6 K. Here we find that radiation pressure plays an important role, but also that these highly dynamical set-ups push our approximate treatment towards the limit of physical applicabil...

  7. Performance analysis of Wald-statistic based network detection methods for radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Satyabrata [ORNL; Rao, Nageswara S [ORNL; Wu, Qishi [University of Memphis; Barry, M. L.. [New Jersey Institute of Technology; Grieme, M. [New Jersey Institute of Technology; Brooks, Richard R [ORNL; Cordone, G. [Clemson University

    2016-01-01

    There have been increasingly large deployments of radiation detection networks that require computationally fast algorithms to produce prompt results over ad-hoc sub-networks of mobile devices, such as smart-phones. These algorithms are in sharp contrast to complex network algorithms that necessitate all measurements to be sent to powerful central servers. In this work, at individual sensors, we employ Wald-statistic based detection algorithms which are computationally very fast, and are implemented as one of three Z-tests and four chi-square tests. At fusion center, we apply the K-out-of-N fusion to combine the sensors hard decisions. We characterize the performance of detection methods by deriving analytical expressions for the distributions of underlying test statistics, and by analyzing the fusion performances in terms of K, N, and the false-alarm rates of individual detectors. We experimentally validate our methods using measurements from indoor and outdoor characterization tests of the Intelligence Radiation Sensors Systems (IRSS) program. In particular, utilizing the outdoor measurements, we construct two important real-life scenarios, boundary surveillance and portal monitoring, and present the results of our algorithms.

  8. Interaction of radiation-generated free radicals with collagen and metalloproteins using cesium-137 gamma source

    Science.gov (United States)

    Shieh, James J.; Wierbicki, Eugen

    The interaction of collagen and metalloproteins with radiation-generated radicals has been studied using spectrophotometric, chromatographic, and ESR techniques. The hydroxyl radical (·OH) reacted with and caused polymerization of acid soluble collagen. Similar reactions were also observed in a ferrimyoglobin and cytochrome C system. Insoluble collagen from bovine muscle subjected to radiation is followed by a first-order process for the decay of free radicals, depending on relative humidity of the system. When the samples were irradiated with 3 kGy at 25°C by a Cesium-137 Irradiator, the observed half life (hr) of free radicals in the samples decreased with increase of relative humidity RH: 31% > 69% > 100%. When collagen, previously kept dry or under 31% RH, was irradiated with 3 kGy at 77°K (-196°C), the decay of free radicals reached a plateau with annealing at -120°C or higher. The decay kept decreasing with annealing at -100°C or higher temperature when collagen maintained at 69 and 100% RH was used. It is concluded that the free radicals in moistened collagen from bovine muscle decreased at a higher rate than in dried collagen. This suggests that free radicals may persist for a longer period of time in irradiated dry proteins of food or animal feed than in foods of higher moisture extent.

  9. Focal waveforms for various source waveforms driving a prolate-spheroidal impulse radiating antenna (IRA)

    Science.gov (United States)

    Altunc, Serhat; Baum, Carl E.; Christodoulou, Christos G.; Schamiloglu, Edl; Buchenauer, C. Jerald

    2008-08-01

    Impulse radiating antennas (IRAs) are designed to radiate very fast pulses in a narrow beam with low dispersion and high field amplitude. For this reason they have been used in a variety of applications. IRAs have been developed for use in the transient far-field region using parabolic reflectors. However, in this paper we focus in the near field region and develop the field waveform at the second focus of a prolate-spheroidal IRA. Certain skin cancers can be killed by the application of a high-amplitude electric field pulse. This can be accomplished by either inserting electrodes near the skin cancer or by applying fast, high-electric field pulses without direct contact. We investigate a new manifestation of an IRA, in which we use a prolate spheroid as a reflector instead of a parabolic reflector and focus in the near-field region instead of the far-field region. This technique minimizes skin damage associated with inserting electrodes near the tumor. Analytical and experimental behaviors for the focal waveforms of two and four-feed arm prolate-spheroidal IRAs are explored. With appropriate choice of the driving waveform we maximize the impulse field at the second focus. The focal waveform of a prolate-spheroidal IRA has been explained theoretically and verified experimentally.

  10. Image-guided linear accelerator-based spinal radiosurgery for hemangioblastoma.

    Science.gov (United States)

    Selch, Michael T; Tenn, Steve; Agazaryan, Nzhde; Lee, Steve P; Gorgulho, Alessandra; De Salles, Antonio A F

    2012-01-01

    To retrospectively review the efficacy and safety of image-guided linear accelerator-based radiosurgery for spinal hemangioblastomas. Between August 2004 and September 2010, nine patients with 20 hemangioblastomas underwent spinal radiosurgery. Five patients had von Hipple-Lindau disease. Four patients had multiple tumors. Ten tumors were located in the thoracic spine, eight in the cervical spine, and two in the lumbar spine. Tumor volume varied from 0.08 to 14.4 cc (median 0.72 cc). Maximum tumor dimension varied from 2.5 to 24 mm (median 10.5 mm). Radiosurgery was performed with a dedicated 6 MV linear accelerator equipped with a micro-multileaf collimator. Median peripheral tumor dose and prescription isodose were 12 Gy and 90%, respectively. Image guidance was performed by optical tracking of infrared reflectors, fusion of oblique radiographs with dynamically reconstructed digital radiographs, and automatic patient positioning. Follow-up varied from 14 to 86 months (median 51 months). Kaplan-Meier estimated 4-year overall and solid tumor local control rates were 90% and 95%, respectively. One tumor progressed 12 months after treatment and a new cyst developed 10 months after treatment in another tumor. There has been no clinical or imaging evidence for spinal cord injury. Results of this limited experience indicate linear accelerator-based radiosurgery is safe and effective for spinal cord hemangioblastomas. Longer follow-up is necessary to confirm the durability of tumor control, but these initial results imply linear accelerator-based radiosurgery may represent a therapeutic alternative to surgery for selected patients with spinal hemangioblastomas.

  11. GENII-LIN-2.1: an open source software system for calculating radiation dose and risk from radionuclides released to the environment.

    Science.gov (United States)

    Teodori, Francesco; Sumini, Marco

    2008-12-01

    GENII-LIN is an open source radiation protection environmental software system running on the Linux operating system. It has capabilities for calculating radiation dose and risk to individuals or populations from radionuclides released to the environment and from pre-existing environmental contamination. It can handle exposure pathways that include ingestion, inhalation and direct exposure to air, water and soil. The package is available for free and is completely open source, i.e., transparent to the users, who have full access to the source code of the software.

  12. Development of a Tandem-Electrostatic-Quadrupole facility for Accelerator-Based Boron Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kreiner, A.J., E-mail: kreiner@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina)] [CONICET, Buenos Aires (Argentina); Castell, W. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Di Paolo, H. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina)] [Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina); Baldo, M. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Bergueiro, J. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina)] [CONICET, Buenos Aires (Argentina)

    2011-12-15

    We describe the present status of an ongoing project to develop a Tandem-ElectroStatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based (AB)-BNCT. The project final goal is a machine capable of delivering 30 mA of 2.4 MeV protons to be used in conjunction with a neutron production target based on the {sup 7}Li(p,n){sup 7}Be reaction. The machine currently being constructed is a folded TESQ with a high-voltage terminal at 0.6 MV. We report here on the progress achieved in a number of different areas.

  13. Studies of Collisional and Nonlinear Radiative Processes for Development of Coherent UV and XUV Sources

    Science.gov (United States)

    1991-06-04

    G. T. Schappert, "Kilovolt X-Ray Spectroscopy of a Subpicosecond- Laser-Excited Source," Phys. Rev. A 39, 454 (1989). 83. R. Fedosejevs, R. Ottmann ...16 OPTICS LETTERS 1263 The authors gratefully acknowledge discussions 4. R. Fedosejevs, R. Ottmann , R. Sigel, G. Kihnle, S. with G. Gibson and the

  14. The EUV Emission in the Coma Cluster of Galaxies and the Underlying Source of this Radiation

    CERN Document Server

    Bowyer, S; Lampton, M; Jones, T W

    2004-01-01

    Observations with the Extreme Ultraviolet Explorer (EUVE) have shown the Coma Cluster to be a source of EUV emission in excess of that produced by X-ray gas in the cluster. We have re-examined the EUVE data on this cluster in an attempt to obtain clues as to the origin of this emission. We find two important new results. First, the ratio between the azimuthally averaged EUV excess emission and the ROSAT hard X-ray flux is constant as a function of distance from the cluster center outward. Second, a correlation analysis between the EUV excess emission and the X-ray emission shows that on a detailed level the EUV excess is spatially closely related to the X-ray emission. These findings contradict previous suggestions as to the underlying source of the diffuse EUV emission in Coma and provide important information in regards to the true source of this emission. We propose a new explanation for the source of this emission: inverse Compton scattering of microwave background photons by secondary electrons and posit...

  15. On the dependence of the two-level source function on its radiation field.

    Science.gov (United States)

    Steinitz, R.; Shine, R. A.

    1973-01-01

    The consequences of the universally made assumption that the stimulated emission profile is identical to the absorption profile are quantitatively investigated for a two-level atom with Doppler redistribution. The nonlinear terms arising in the source function are evaluated iteratively. We find that the magnitude of the effects is probably completely negligible for visible and UV solar lines.

  16. A high-performance doped photocatalysts for inactivation of total coliforms in superficial waters using different sources of radiation.

    Science.gov (United States)

    Claro, Elis Marina Turini; Bidoia, Ederio Dino; de Moraes, Peterson Bueno

    2016-07-15

    Photocatalytic water treatment has a currently elevated electricity demand and maintenance costs, but the photocatalytic water treatment may also assist in overcoming the limitations and drawbacks of conventional water treatment processes. Among the Advanced Oxidation Processes, heterogeneous photocatalysis is one of the most widely and efficiently used processes to degrade and/or remove a wide range of polluting compounds. The goal of this work was to find out a highly efficient photocatalytic disinfection process in superficial water with different doped photocatalysts and using three sources of radiation: mercury vapor lamp, solar simulator and UV-A LED. Three doped photocatalysts were prepared, SiZnO, NSiZnO and FNSiZnO. The inactivation efficiency of each synthesized photocatalysts was compared to a TiO2 P25 (Degussa(®)) 0.5 g L(-1) control. Photolysis inactivation efficiency was 85% with UV-A LED, which is considered very high, demanding low electricity consumption in the process, whereas mercury vapor lamp and solar simulator yielded 19% and 13% inactivation efficiency, respectively. The best conditions were found with photocatalysts SiZnO, FNSiZnO and NSiZnO irradiated with UV-A LED, where efficiency exceeded 95% that matched inactivation of coliforms using the same irradiation and photocatalyst TiO2. All photocatalysts showed photocatalytic activity with all three radiation sources able to inactivate total coliforms from river water. The use of UV-A LED as the light source without photocatalyst is very promising, allowing the creation of cost-effective and highly efficient water treatment plants.

  17. A model to predict modal radiation by finite-sized sources in semi-infinite isotropic plates

    Science.gov (United States)

    Stévenin, M.; Lhémery, A.; Grondel, S.

    2017-01-01

    Elastic guided wave (GW) propagation is involved in various non-destructive testing (NDT) techniques of plate-like structures. The present paper aims at describing an efficient model to predict the GW field radiated by various sources attached at a distance of the straight boundary of an isotropic plate, a configuration often encountered in typical examinations. Since the interpretation of GW propagation and scattering in plates is made easier by the use of modal description, the model is derived in the classical theoretical framework of modal solutions. Direct radiation by a uniform source of finite size in an isotropic plate can be efficiently modelled by deriving Fraunhofer-like approximation. A rigorous treatment is proposed based upon i) the stationary phase method to describe the field after reflection at a plate edge, ii) on the computation of modal reflection coefficients for an arbitrary incidence relative to the edge and iii) on the Fraunhofer approximation to account for the finite size of the source. The stationary phase method allows us to easily express the amplitude of reflected modes, that is to say, the way waves spread, including reflections involving mode conversions. The computation of modal reflection coefficients for plane GW at oblique incidence was recently treated in the literature and our work for this very problem simply consisted in adapting it to the SAFE calculation we use to compute modal solutions. The overall computation of the direct and reflected contributions is numerically very efficient. Once the total field is computed at a given frequency, the time-dependent field is obtained by simple Fourier synthesis.

  18. Source sector and region contributions to concentration and direct radiative forcing of black carbon in China

    Science.gov (United States)

    Li, Ke; Liao, Hong; Mao, Yuhao; Ridley, David A.

    2016-01-01

    We quantify the contributions from five domestic emission sectors (residential, industry, transportation, energy, and biomass burning) and emissions outside of China (non-China) to concentration and direct radiative forcing (DRF) of black carbon (BC) in China for year 2010 using a nested-grid version of the global chemical transport model (GEOS-Chem) coupled with a radiative transfer model. The Hemispheric Transport of Air Pollution (HTAP) anthropogenic emissions of BC for year 2010 are used in this study. Simulated surface-layer BC concentrations in China have strong seasonal variations, which exceed 9 μg m-3 in winter and are about 1-5 μg m-3 in summer in the North China Plain and the Sichuan Basin. Residential sector is simulated to have the largest contribution to surface BC concentrations, by 5-7 μg m-3 in winter and by 1-3 μg m-3 in summer, reflecting the large emissions from winter heating and the enhanced wet deposition during summer monsoon. The contribution from industry sector is the second largest and shows relatively small seasonal variations; the emissions from industry sector contribute 1-3 μg m-3 to BC concentrations in the North China Plain and the Sichuan Basin. The contribution from transportation sector is the third largest, followed by that from biomass burning and energy sectors. The non-China emissions mainly influence the surface-layer concentrations of BC in western China; about 70% of surface-layer BC concentration in the Tibet Plateau is attributed to transboundary transport. Averaged over all of China, the all-sky DRF of BC at the top of the atmosphere (TOA) is simulated to be 1.22 W m-2. Sensitivity simulations show that the TOA BC direct radiative forcings from the five domestic emission sectors of residential, industry, energy, transportation, biomass burning, and non-China emissions are 0.44, 0.27, 0.01, 0.12, 0.04, and 0.30 W m-2, respectively. The domestic and non-China emissions contribute 75% and 25% to BC DRF in China

  19. Directional radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, Jonathan L.

    2017-09-12

    Directional radiation detectors and systems, methods, and computer-readable media for using directional radiation detectors to locate a radiation source are provided herein. A directional radiation detector includes a radiation sensor. A radiation attenuator partially surrounds the radiation sensor and defines an aperture through which incident radiation is received by the radiation sensor. The aperture is positioned such that when incident radiation is received directly through the aperture and by the radiation sensor, a source of the incident radiation is located within a solid angle defined by the aperture. The radiation sensor senses at least one of alpha particles, beta particles, gamma particles, or neutrons.

  20. Analysis for Radiation and Shielding Dose in Plasma Focus Neutron Source Using FLUKA

    Science.gov (United States)

    Nemati, M. J.; Amrollahi, R.; Habibi, M.

    2012-06-01

    Monte Carlo simulations have been performed for the attenuation of neutron radiation produced at Plasma focus (PF) devices through various shielding design. At the test site it will be fired with deuterium and tritium (D-T) fusion resulting in a yield of about 1013 fusion neutrons of 14 MeV. This poses a radiological hazard to scientists and personnel operating the device. The goal of this paper was to evaluate various shielding options under consideration for the PF operating with D-T fusion. Shields of varying neutrons-shielding effectiveness were investigated using concrete, polyethylene, paraffin and borated materials. The most effective shield, a labyrinth structure, allowed almost 1,176 shots per year while keeping personnel under 20 mSV of dose. The most expensive shield that used, square shield with 100 cm concrete thickness on the walls and Borated paraffin along with borated polyethylene added outside the concrete allowed almost 15,000 shot per year.

  1. Surface oscillations — A possible source of fracture induced electromagnetic radiation

    Science.gov (United States)

    Rabinovitch, A.; Frid, V.; Bahat, D.

    2007-02-01

    Radio frequency electromagnetic radiation (EMR) registered hundreds of kilometres away from an earthquake epicentre is detected hours before earthquakes. Yet, accurate earthquakes prediction by their self-induced EMR still remains in its infancy due in part to the lack of understanding of EMR's origin. Here we present a viable model of this origin, according to which EMR is emitted by an oscillating dipole created by ions moving collectively as a surface wave on both sides of the crack; when the crack halts, the EMR pulse amplitude decays by interaction with bulk phonons. The model is shown to be able to provide crack dimensions and velocities, to explain some general similarities of different fracturing processes and indicate the existence of a general failure mechanism. Results raise the hope of developing an EMR based genuine earthquake prediction system.

  2. Method and system for determining depth distribution of radiation-emitting material located in a source medium and radiation detector system for use therein

    Energy Technology Data Exchange (ETDEWEB)

    Benke, Roland R.; Kearfott, Kimberlee J.; McGregor, Douglas S.

    2004-04-27

    A radiation detector system includes detectors having different properties (sensitivity, energy resolution) which are combined so that excellent spectral information may be obtained along with good determinations of the radiation field as a function of position.

  3. SU-E-T-253: Open-Source Automatic Software for Quantifying Biological Assays of Radiation Effects

    Energy Technology Data Exchange (ETDEWEB)

    Detappe, A [University of Lyon (France); Dana-Farber Cancer Institute, Boston, MA (United States); Korideck, H [Dana-Farber Cancer Institute, Boston, MA (United States); Makrigiorgos, G; Berbeco, R [Dana-Farber Cancer Institute, Boston, MA (United States); Brigham and Women' s Hospital, Boston, MA (United States)

    2014-06-01

    Purpose: Clonogenic cell survival is a common assay for quantifying the effect of drugs and radiation. Manual counting of surviving colonies can take 30–90seconds per plate, a major limitation for large studies. Currently available automatic counting tools are not easily modified for radiation oncology research. Our goal is to provide an open-source toolkit for precise, accurate and fast analysis of biological assays in radiation oncology. Methods: As an example analysis, we used HeLa cells incubated with gadolinium nanoparticles prior to irradiation. After treatment, the cells are grown for 14days to allow for colony formation. To analyze the colony growth, we capture images of each dish for archiving and automatic computer-based analysis. A FujifilmX20 camera is placed at the top of a box setup, 20cm above the sample, which is backlit by a LED lamp placed at the bottom of the box. We use a Gaussian filter (width=1.3mm) and color threshold (19–255). The minimum size for a colony to be counted is 1mm. For this example, 20 dishes with a large range of colonies were analyzed. Each dish was counted 3 times manually by 3 different users and then compared to our counter. Results: Automatic counting of cell colonies takes an average of 7seconds, enabling the analysis process to be accelerated 4–12 times. The average precision of the automatic counter was 1.7%. The Student t-test demonstrated the non-significant differences between the two counting methods (p=0.64). The ICC demonstrated the reliability of each method with ICC>0.999 (automatic) and ICC=0.95 (manual). Conclusion: We developed an open-source automatic toolkit for the analysis of biological assays in radiation oncology and demonstrated the accuracy, precision and effort savings for clonogenic cell survival quantification. This toolkit is currently being used in two laboratories for routine experimental analysis and will be made freely available on our departmental website.

  4. Evaluating laser-driven Bremsstrahlung radiation sources for imaging and analysis of nuclear waste packages.

    Science.gov (United States)

    Jones, Christopher P; Brenner, Ceri M; Stitt, Camilla A; Armstrong, Chris; Rusby, Dean R; Mirfayzi, Seyed R; Wilson, Lucy A; Alejo, Aarón; Ahmed, Hamad; Allott, Ric; Butler, Nicholas M H; Clarke, Robert J; Haddock, David; Hernandez-Gomez, Cristina; Higginson, Adam; Murphy, Christopher; Notley, Margaret; Paraskevoulakos, Charilaos; Jowsey, John; McKenna, Paul; Neely, David; Kar, Satya; Scott, Thomas B

    2016-11-15

    A small scale sample nuclear waste package, consisting of a 28mm diameter uranium penny encased in grout, was imaged by absorption contrast radiography using a single pulse exposure from an X-ray source driven by a high-power laser. The Vulcan laser was used to deliver a focused pulse of photons to a tantalum foil, in order to generate a bright burst of highly penetrating X-rays (with energy >500keV), with a source size of waste materials. This feasibility study successfully demonstrated non-destructive radiography of encapsulated, high density, nuclear material. With recent developments of high-power laser systems, to 10Hz operation, a laser-driven multi-modal beamline for waste monitoring applications is envisioned.

  5. Theoretical Models for Producing Circularly Polarized Radiation in Extragalactic Radio Sources

    CERN Document Server

    Wardle, J F C; Wardle, John F. C.; Homan, Daniel C.

    2003-01-01

    We discuss the production of circular polarization in compact radio sources both by the intrinsic mechanism and by Faraday conversion. We pay particular attention to the magnetic field structure, considering partially ordered fiel ds and Laing sheets, and distinguishing between uniform and unidirectional fields. (The latter can be constrained b y flux conservation arguments.) In most cases, Faraday conversion is the more important mechanism. Conversion opera tes on Stokes U, which can be generated by internal Faraday rotation, or by magnetic field fluctuations, which can therefore produce circular polarization even in a pure pair plasma. We also show that the spectrum of circular pola rization in an inhomogeneous jet can be quite different from that in a uniform source, being flat or even inverted.

  6. L-shell spectroscopic diagnostics of radiation from krypton HED plasma sources

    Science.gov (United States)

    Petkov, E. E.; Safronova, A. S.; Kantsyrev, V. L.; Shlyaptseva, V. V.; Rawat, R. S.; Tan, K. S.; Beiersdorfer, P.; Hell, N.; Brown, G. V.

    2016-11-01

    X-ray spectroscopy is a useful tool for diagnosing plasma sources due to its non-invasive nature. One such source is the dense plasma focus (DPF). Recent interest has developed to demonstrate its potential application as a soft x-ray source. We present the first spectroscopic studies of krypton high energy density plasmas produced on a 3 kJ DPF device in Singapore. In order to diagnose spectral features, and to obtain a more comprehensive understanding of plasma parameters, a new non-local thermodynamic equilibrium L-shell kinetic model for krypton was developed. It has the capability of incorporating hot electrons, with different electron distribution functions, in order to examine the effects that they have on emission spectra. To further substantiate the validity of this model, it is also benchmarked with data gathered from experiments on the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory, where data were collected using the high resolution EBIT calorimeter spectrometer.

  7. Environmental radiation safety: source term modification by soil aerosols. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Moss, O.R.; Allen, M.D.; Rossignol, E.J.; Cannon, W.C.

    1980-08-01

    The goal of this project is to provide information useful in estimating hazards related to the use of a pure refractory oxide of /sup 238/Pu as a power source in some of the space vehicles to be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere, and to impact with the earth's surface without releasing any plutonium, the possibility that such an event might produce aerosols composed of soil and /sup 238/PuO/sub 2/ cannot be absolutely excluded. This report presents the results of our most recent efforts to measure the degree to which the plutonium aerosol source term might be modified in a terrestrial environment. The five experiments described represent our best effort to use the original experimental design to study the change in the size distribution and concentration of a /sup 238/PuO/sub 2/ aerosol due to coagulation with an aerosol of clay or sandy loam soil.

  8. L-shell spectroscopic diagnostics of radiation from krypton HED plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Petkov, E. E., E-mail: emilp@unr.edu; Safronova, A. S.; Kantsyrev, V. L.; Shlyaptseva, V. V. [University of Nevada, Reno, Nevada 89557 (United States); Rawat, R. S.; Tan, K. S. [National Institute of Education, Nanyang Technological University, Singapore 637616 (Singapore); Beiersdorfer, P.; Brown, G. V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hell, N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Dr. Remeis-Sternwarte and ECAP, Universität Erlangen-Nürnberg, 96049 Bamberg (Germany)

    2016-11-15

    X-ray spectroscopy is a useful tool for diagnosing plasma sources due to its non-invasive nature. One such source is the dense plasma focus (DPF). Recent interest has developed to demonstrate its potential application as a soft x-ray source. We present the first spectroscopic studies of krypton high energy density plasmas produced on a 3 kJ DPF device in Singapore. In order to diagnose spectral features, and to obtain a more comprehensive understanding of plasma parameters, a new non-local thermodynamic equilibrium L-shell kinetic model for krypton was developed. It has the capability of incorporating hot electrons, with different electron distribution functions, in order to examine the effects that they have on emission spectra. To further substantiate the validity of this model, it is also benchmarked with data gathered from experiments on the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory, where data were collected using the high resolution EBIT calorimeter spectrometer.

  9. Pedestrian movement analysis in transfer station corridor: Velocity-based and acceleration-based

    Science.gov (United States)

    Ji, Xiangfeng; Zhang, Jian; Hu, Yongkai; Ran, Bin

    2016-05-01

    In this paper, pedestrians are classified into aggressive and conservative ones by their temper. Aggressive pedestrians' walking through crowd in transfer station corridor is analyzed. Treating pedestrians as particles, this paper uses the modified social force model (MSFM) as the building block, where forces involve self-driving force, repulsive force and friction force. The proposed model in this paper is a discrete model combining the MSFM and cellular automata (CA) model, where the updating rules of the CA are redefined with MSFM. Due to the continuity of values generated by the MSFM, we use the fuzzy logic to discretize the continuous values into cells pedestrians can move in one step. With the observation that stimulus around pedestrians influences their acceleration directly, an acceleration-based movement model is presented, compared to the generally reviewed velocity-based movement model. In the acceleration-based model, a discretized version of kinematic equation is presented based on the acceleration discretized with fuzzy logic. In real life, some pedestrians would rather keep their desired speed and this is also mimicked in this paper, which is called inertia. Compared to the simple triangular membership function, a trapezoidal membership function and a piecewise linear membership function are used to capture pedestrians' inertia. With the trapezoidal and the piecewise linear membership function, many overlapping scenarios should be carefully handled and Dubois and Prade's four-index method is used to completely describe the relative relationship of fuzzy quantities. Finally, a simulation is constructed to demonstrate the effect of our model.

  10. Medical applications of synchrotron radiation at the National Synchrotron Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Thomlinson, W.

    1992-10-01

    The overriding features of the synchrotron beams which make them applicable to medical research are their extremely high intensity and broadband energy spectrum. Several orders of magnitude separate the smooth, continuous spectrum of the synchrotron from the sharply peaked characteristic emission spectrum of a conventional source. Basically, the high intensity and tunability allow monochromatic beams to be generated at virtually any energy. The standard problem of beam hardening in both medical imaging and therapy is eliminated by the monochromatic beams since the energy spectrum does not change with passage through tissue. The tunable spectrum allows enhancement of images and therapeutic dose by selection of the most effective energy for a given procedure.

  11. Medical applications of synchrotron radiation at the National Synchrotron Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Thomlinson, W.

    1992-01-01

    The overriding features of the synchrotron beams which make them applicable to medical research are their extremely high intensity and broadband energy spectrum. Several orders of magnitude separate the smooth, continuous spectrum of the synchrotron from the sharply peaked characteristic emission spectrum of a conventional source. Basically, the high intensity and tunability allow monochromatic beams to be generated at virtually any energy. The standard problem of beam hardening in both medical imaging and therapy is eliminated by the monochromatic beams since the energy spectrum does not change with passage through tissue. The tunable spectrum allows enhancement of images and therapeutic dose by selection of the most effective energy for a given procedure.

  12. Semiconductor-Superlattice Parametric Oscillator as a Subterahertz and Possible Terahertz Radiation Source

    Directory of Open Access Journals (Sweden)

    Karl F. Renk

    2007-01-01

    Full Text Available We describe the operation of a semiconductor-superlattice parametric oscillator (SPO at a subterahertz frequency (near 300 GHz. The oscillator is driven by a microwave source (frequency near 100 GHz. We also present an analysis indicating that operation at frequencies above 1 THz should be possible. The SPO is based on the ability of conduction electrons in a superlattice to perform Bloch oscillations. Broadband tunability as well as the monochromacy of a driving microwave field are transferred to the SPO.

  13. A laser-generated plasma as a source of VUV continuum radiation for photoelectronic spectroscopy

    OpenAIRE

    Heckenkamp, Ch.; Heinzmann, Ulrich; Schönhense, G.; BURGESS.D.D; Thorne, A. P.; Wheaton, J. E. G.

    1981-01-01

    The feasibility of using laser-generated plasmas as VUV continuum sources for photoelectron spectroscopy has been demonstrated by measuring the spectral intensity distribution of the VUV continuum in the wavelength region from 79 to 43 nm by energy analysis of the photoelectrons ejected from argon atoms. The maximum photon flux obtained after reflection at a gold-coated spherical mirror was of the order of 10(11) photons nm(-1) per pulse at 50 nm for a laser energy of 830 mJ. The results show...

  14. Development of monoenergetic electron beam sources for radiation-instrument calibration

    Science.gov (United States)

    Soares, C. G.; Dick, C. E.; Pruitt, J. S.; Sparrow, J. H.

    1985-05-01

    Accelerator-produced electron beams are being studied for use in obtaining the response of beta-particle dosimetry instrumenta- tion as a function of electron energy. The NBS 4 MV Van de Graaff and 500 kV cascaded rectifier accelerators are being used to generate electron beams from 200 keV to 2.5 MeV. A device capable of scanning the electron beam in two dimensions over an area large enough to cover radiation-survey instruments uniformly is attached to the beam-handling system of each accelerator. The scanned beam exits from vacuum through a 16 cm 2 window consisting of either 25 μm Kapton (for energies below 500 keV) or 100 μm aluminum. The electron beams produced have been characterized in terms of (1) spatial distribution, (2) energy spectrum, and (3) absorbed dose to plastic. Spatial distributions were determined using film, while spectra were measured using a 5 mm-deep Si surface barrier detector. An extrapolation chamber is being used for beam standardization in terms of absorbed dose to plastic.

  15. Development of monoenergetic electron beam sources for radiation-instrument calibration

    Energy Technology Data Exchange (ETDEWEB)

    Soares, C.G.; Dick, C.E.; Pruitt, J.S.; Sparrow, J.H.

    1985-05-15

    Accelerator-produced electron beams are being studied for use in obtaining the response of beta-particle dosimetry instrumentation as a function of electron energy. The NBS 4 MV Van de Graaff and 500 kV cascaded rectifier accelerators are being used to generate electron beams from 200 keV to 2.5 MeV. A device capable of scanning the electron beam in two dimensions over an area large enough to cover radiation-survey instruments uniformly is attached to the beam-handling system of each accelerator. The scanned beam exits from vacuum through a 16 cm/sup 2/ window consisting of either 25 ..mu..m Kapton (for energies below 500 keV) or 100 ..mu..m aluminum. The electron beams produced have been characterized in terms of (1) spatial distribution, (2) energy spectrum, and (3) absorbed dose to plastic. Spatial distributions were determined using film, while spectra were measured using a 5 mm-deep Si surface barrier detector. An extrapolation chamber is being used for beam standardization in terms of absorbed dose to plastic. (orig.).

  16. Radiolysis of TBP in the presence of plutonium and uranium. [Gamma radiation; alpha sources

    Energy Technology Data Exchange (ETDEWEB)

    Kulikov, I.A.; Kermanov, N.V.; Vladimirova, M.V.

    1983-01-01

    Using the methods of potentiometry, spectrophotometry and chromatography the yields of TBP decomposition products during ..cap alpha..- and ..gamma..-radiolysis in the two-phase system of 30% TBP in n-paraffin-3.0 mol/l HNO/sub 3/ in the presence of Pusup((4)) (10/sup -3/-10/sup -1/ mol/l) and Usup((6)) (0.01-0.3 mol/l) have been determined. Formation yields of Pusup((4)) complexes with dibutylphosphoric acid (DBPA) and monobutylphosphoric (MBPA) acid in the two-phase system studied are found. It is shown that, with an increase in (Me) from 0.01 to 0.3 mol/l, the G of DBPA increases from 1.9 to 3.0, and the G of MBPA - from 0.3 to 0.45 molecules/100 eV. Radiative gas evolution composition and yields of gaseous radiolysis products of the organic phase have been studied. Kinetics of DBPA formation in the presence of plutonium is considered. Constants of DBPA formation and decomposition rates are determined. On the basis of experimental data the maximum yield of the TBP decomposition is calculated to be equal to approximately 6.0 molecules/100 eV.

  17. LSO background radiation as a transmission source using time of flight.

    Science.gov (United States)

    Rothfuss, Harold; Panin, Vladimir; Moor, Andrew; Young, John; Hong, Inki; Michel, Christian; Hamill, James; Casey, Michael

    2014-09-21

    LSO scintillators (Lu2Sio5:Ce) have a background radiation which originates from the isotope Lu-176 that is present in natural occurring lutetium. The decay that occurs in this isotope is a beta decay that is in coincidence with cascade gamma emissions with energies of 307,202 and 88 keV. The coincidental nature of the beta decay with the gamma emissions allow for separation of emission data originating from a positron annihilation event from transmission type data from the Lu-176 beta decay. By using the time of flight information, and information of the chord length between two LSO pixels in coincidence as a result of a beta emission and emitted gamma, a second time window can be set to observe transmission events simultaneously to emission events. Using the time when the PET scanner is not actively acquiring positron emission data, a continuous blank can be acquired and used to reconstruct a transmission image. With this blank and the measured transmission data, a transmission image can be reconstructed. This reconstructed transmission image can be used to perform emission data corrections such as attenuation correction and scatter corrections or starting images for algorithms that estimate emission and attenuation simultaneously. It is observed that the flux of the background activity is high enough to create useful transmission images with an acquisition time of 10 min.

  18. Quantum collapse as source of the seeds of cosmic structure during the radiation era

    CERN Document Server

    León, Gabriel; Piccirilli, María Pía

    2014-01-01

    The emergence of the seeds of cosmic structure, from a perfect isotropic and homogeneous Universe, has not been clearly explained by the standard version of inflationary models as the dynamics involved preserve the homogeneity and isotropy at all times. A proposal that attempts to deal with this problem, by introducing "the self-induced collapse hypothesis," has been introduced by D. Sudarsky and collaborators in previous papers. In all these works, the collapse of the wave function of the inflaton mode is restricted to occur during the inflationary period. In this paper, we analyse the possibility that the collapse happens during the radiation era. A viable model can be constructed under the condition that the inflaton field variable must be affected by the collapse while the momentum variable can or cannot be affected. Another condition to be fulfilled is that the time of collapse must be independent of $k$. However, when comparing with recent observational data, the predictions of the model cannot be disti...

  19. Newborn Magnetars as sources of Gravitational Radiation: constraints from High Energy observations of Magnetar Candidates

    CERN Document Server

    Dall'Osso, S; Osso, Simone Dall'; Stella, Luigi

    2007-01-01

    Soft Gamma Repeaters and the Anomalous X-ray Pulsars are believed to contain slowly spinning "magnetars". The enormous energy liberated in the 2004 Dece 27 giant flare from SGR 1806-20, together with the likely recurrence time of such events, points to an internal magnetic field strength ~ 10^{16} G. Such strong fields are expected to be generated by a coherent alpha-Omega dynamo in the early seconds after the Neutron Star formation, if its spin period is of a few milliseconds at most. A substantial deformation of the NS is caused by such fields and a newborn millisecond-spinning magnetar would thus radiate for a few days a strong gravitational wave signal. Such a signal may be detected with Advanced LIGO-class detectors up to the distance of the Virgo cluster, where ~ 1 magnetar per year are expected to form. Recent X-ray observations reveal that SNRs around magnetar candidates do not show evidence for a larger energy content than standard SNRs (Vink & Kuiper 2006). This is at variance with what would be...

  20. Regularities pertinent to heat transfer between torch gas layers and steam boiler firebox waterwalls. Part I. Geometrical and physical torch model as a source of heat radiation

    Science.gov (United States)

    Makarov, A. N.

    2014-09-01

    The progress seen in the 19th-21st centuries in the development of methods for calculating heat transfer in torch furnaces, fireboxes, and combustion chambers is analyzed. Throughout the 20th century, calculations of heat transfer were carried out based on the law for radiation from solid bodies deduced by Y. Stefan and L. Boltzmann. It is shown that the use of this law for calculating heat transfer of a torch (a gaseous source of radiation) in heating furnaces and power-generating installations leads to incorrect results. It is substantiated that there is crisis of methods for calculating heat transfer in torch furnaces and power-generating installations. Geometrical and physical torch models in the form of radiating cylindrical gas volumes as sources of heat radiation are proposed for overcoming this crisis.