Incidents with hazardous radiation sources

International Nuclear Information System (INIS)

Schoenhacker, Stefan

2016-01-01

Incidents with hazardous radiation sources can occur in any country, even those without nuclear facilities. Preparedness for such incidents is supposed to fulfill globally agreed minimum standards. Incidents are categorized in incidents with licensed handling of radiation sources as for material testing, transport accidents of hazardous radiation sources, incidents with radionuclide batteries, incidents with satellites containing radioactive inventory, incidents wit not licensed handling of illegally acquired hazardous radiation sources. The emergency planning in Austria includes a differentiation according to the consequences: incidents with release of radioactive materials resulting in restricted contamination, incidents with release of radioactive materials resulting in local contamination, and incidents with the hazard of e@nhanced exposure due to the radiation source.

Construction of x-ray Kβ filters to monochromatize the radiation of a conventional x-ray tube

International Nuclear Information System (INIS)

Moreira, M.V.B.; Oliveira, A.G.

1987-01-01

The construction of Zr and Nb Kβ filters to produce monochromatic radiation of a conventional X-ray Mo-tube (λK a = 0.7107 A) is described. Disks of NB and Zr, 6.4 mm in diameter and 0.03 to 0.06 mm thick, were prepared. The filters performance was tested by means of NaCl powder difraction patterns. (author) [pt

Comparison of UV action spectra for lethality and mutation in Salmonella typhimurium using a broad band source and monochromatic radiations

International Nuclear Information System (INIS)

Calkins, John; Selby, Christopher; Enoch, H.G.

1987-01-01

The UV-B region (280-320 nm) is thought to be primarily responsible for the mutagenic, lethal, and carcinogenic effects of solar radiation. We have conducted UV-B action spectroscopy for mutagenesis and survival of Ames' Salmonella typhimurium strain TA98 (uvrB, pKM101) using both monochromatic radiation from a dye laser and broader bandwidth radiation emitted from FS-20 sunlamps. A series of optical filters having different transmission cut-offs together with the sunlamp source provided bandwidths having successively less short wavelength components from which a ''broad band'' action spectrum was deduced. The two sets of action spectra differed both qualitatively and quantitatively: in comparison to the monochromatic action spectra, the ''broad band'' spectra showed up to a 200-fold reduced efficiency for both mutation induction and lethality by UV-B wavelengths. These results suggest a large protective effect of the background UV-A and/or visible radiations which were present during the broad spectrum irradiations and which are also present in solar radiation. Additional experiments show that to the extent tested this protective effect is not due to photo-reactivation or irradiance (dose rate) effects. (author)

A mirror for lab-based quasi-monochromatic parallel x-rays.

Science.gov (United States)

Nguyen, Thanhhai; Lu, Xun; Lee, Chang Jun; Jung, Jin-Ho; Jin, Gye-Hwan; Kim, Sung Youb; Jeon, Insu

2014-09-01

A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in x-ray images as reflected x-rays. The parallelism of the reflected x-rays was investigated using the shape of the bands. The intensity and monochromatic characteristics of the reflected x-rays were evaluated through measurements of the x-ray spectra in the band. High intensity, nearly monochromatic, and parallel x-rays, which can be used for high resolution x-ray microscopes and local radiation therapy systems, were obtained.

Studies on auger enhancement of biological systems with the use of monochromatic synchrotron radiation

International Nuclear Information System (INIS)

Shinohara, K.

1985-01-01

HeLa cells were incubated either with BrdUrd (5 x 10 -5 M) and deoxycytidine (10 -5 M) for 18 hr (corresponding to one generation time) or with gallium citrate (10 -5 M) for 24 hr. The cells on the membrane filter were irradiated with monochromatic synchrotron radiation at 0.90 A, 1.00 A, or 1.14 A and cell survival was determined by colony-forming ability. The results show that the sensitivity of BrdUrd-labeled cells was higher when they were irradiated at 0.90 a than at 100 A, but cells without BrdUrd showed no difference in sensitivity when irradiated at these two wavelengths. The growth curve of HeLa cells in the presence of gallium citrate (10 -4 M). Shows that during the test period of 20-60 hr of colony-forming ability was not affected although the growth rate decreased slightly. Data show no increase in the sensitivity of gallium-labeled HeLa cells over that of controls to irradiation with monochromatic synchrotron radiation at 1.14 A, slightly shorter than the K absorption edge for the gallium (1.196 A). Since gallium has been shown to concentrate in lysosome, the present results, suggest that the range of Auger enhancement is not great enough for interaction with DNA in nucleus from lysosome in cytoplasm, although the possibility should be considered that the accumulated number of gallium atoms (∼ 5 x 10 7 /cell) may not be enough to produce detectable enhancement effects

Monochromatization of synchrotron radiation for studies in photoelectron spectroscopy

International Nuclear Information System (INIS)

Murty, P.S.

1981-01-01

Synchrotron radiation provides a tunable photon source which bridges the wavelength gap between HeI and AlKsub(α) radiation sources in photoelectron spectroscopy. The essential component for using synchrotron radiation is a monochromator. Some design features of the monochromators fabricated at Stanford, U.S.A., and Orsay, France, are described. The Stanford monochromator is a silicon crystal monochromator yielding 8 keV X-ray beam and is used with SPEAR storage ring facility, while the Orsay monochromator is a grazing incidence grating monochromator used for UPS studies. (M.G.B.)

Electromagnetic Radiation of Electrons in Periodic Structures

CERN Document Server

Potylitsyn, Alexander Petrovich

2011-01-01

Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

Radiation incidents in dentistry

International Nuclear Information System (INIS)

Lovelock, D.J.

1996-01-01

Most dental practitioners act as their own radiographer and radiologist, unlike their medical colleagues. Virtually all dental surgeons have a dental X-ray machine for intraoral radiography available to them and 40% of dental practices have equipment for dental panoramic tomography. Because of the low energy of X-ray equipment used in dentistry, radiation incidents tend to be less serious than those associated with other aspects of patient care. Details of 47 known incidents are given. The advent of the 1985 and 1988 Ionising Radiation Regulations has made dental surgeons more aware of the hazards of radiation. These regulations, and general health and safety legislation, have led to a few dental surgeons facing legal action. Because of the publicity associated with these court cases, it is expected that there will be a decrease in radiation incidents arising from the practice of dentistry. (author)

Quantum effects induced by a gap in the spectrum of atom-bath coupling constants: ''Freezing'' of atomic decay and monochromatic collective radiation

International Nuclear Information System (INIS)

Mogilevtsev, D.S.; Kilin, S.Ya.

1994-08-01

A specific kind of inhibition of atomic decay (''freezing of decay) and intense monochromatic collective radiation are predicted for a single two-level atom and for a system of atoms interacting with the field bath having the gap in the spectrum of coupling constants. (author). 10 refs, 5 figs

Imaging-therapy computed tomography with quasi-monochromatic X-rays.

Science.gov (United States)

Jost, Gregor; Golfier, Sven; Lawaczeck, Ruediger; Weinmann, Hanns-Joachim; Gerlach, Martin; Cibik, Levent; Krumrey, Michael; Fratzscher, Daniel; Rabe, Johannis; Arkadiev, Vladimir; Haschke, Michael; Langhoff, Norbert; Wedell, Reiner; Luedemann, Lutz; Wust, Peter; Pietsch, Hubertus

2008-12-01

Computed tomography (CT) is a widespread and highly precise technique working in the energy range around 50-100 keV. For radiotherapy, however, the MeV energy range enables a better dose distribution. This gap between diagnosis and therapy can be overcome by the use of a modified CT machine in combination with heavy elements targeted to the tumour and used as photoelectric radiation enhancer. The experimental setup consists of an X-ray optical module mounted at the exit of the X-ray tube of a clinical CT. The module converts the standard fan-shaped beam into a high intensity, monochromatized and focused beam. The radiation was characterized using an energy-dispersive detection system calibrated by synchrotron radiation and gel dosimetry. The photoelectric radiation enhancement for different elements was calculated and experimentally verified. The X-ray optical module filters selectively the energy of the tungsten K alpha-emission line (59.3 keV) with a full width at half maximum (FWHM) of 5 keV and focused the radiation onto a focal spot which coincides with the isocentre of the gantry. This results in a steep dose gradient at the centre of rotation qualified for locoregional radiation therapy. The photon energy of the quasi-monochromatic radiation agrees with the energy range of maximal photoelectric dose enhancement for gadolinium and iodine. An additional X-ray optical module optimized for targeted therapy and photoelectric dose enhancement allows the combination of diagnosis and radiotherapy on a clinical CT.

The monochromatic imaging mode of a RITA-type neutron spectrometer

International Nuclear Information System (INIS)

Bahl, C.R.H.; Andersen, P.; Klausen, S.N.; Lefmann, K.

2004-01-01

The imaging monochromatic mode of a neutron spectrometer with a multi-bladed RITA analyser system is so far unexplored. We present analytical calculations that define the mode. It is shown that the mode can be realised for PG (0 0 2) analyser crystals, from incident energies of about 3.2 meV and up, allowing the important cases of 3.7, 5.0 and 13.7 meV. Due to beam divergence, the neutron rays from neighbouring analyser blades are found to overlap slightly. Hence, the optimal use of the monochromatic imaging mode would be found by employing an adjustable radial collimator to limit the spread of the ray from each analyser blade

The monochromatic imaging mode of a RITA-type neutron spectrometer

Energy Technology Data Exchange (ETDEWEB)

Bahl, C.R.H. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark) and Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark)]. E-mail: christian.bahl@risoe.dk; Andersen, P. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, DK-2100 Copenhagen (Denmark); Klausen, S.N. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Lefmann, K. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

2004-12-01

The imaging monochromatic mode of a neutron spectrometer with a multi-bladed RITA analyser system is so far unexplored. We present analytical calculations that define the mode. It is shown that the mode can be realised for PG (0 0 2) analyser crystals, from incident energies of about 3.2 meV and up, allowing the important cases of 3.7, 5.0 and 13.7 meV. Due to beam divergence, the neutron rays from neighbouring analyser blades are found to overlap slightly. Hence, the optimal use of the monochromatic imaging mode would be found by employing an adjustable radial collimator to limit the spread of the ray from each analyser blade.

Electromagnetic radiation of electrons in periodic structures

International Nuclear Information System (INIS)

Potylitsyn, Alexander Petrovich

2011-01-01

Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation and the Smith-Purcell effect. Characteristics of such radiation sources and perspectives of their usage are discussed. The recent experimental results as well as their interpretation are presented. (orig.)

Imaging-therapy computed tomography with quasi-monochromatic X-rays

International Nuclear Information System (INIS)

Jost, Gregor; Golfier, Sven; Lawaczeck, Ruediger; Weinmann, Hanns-Joachim; Gerlach, Martin; Cibik, Levent; Krumrey, Michael; Fratzscher, Daniel; Rabe, Johannis; Arkadiev, Vladimir; Haschke, Michael; Langhoff, Norbert; Wedell, Reiner

2008-01-01

Introduction: Computed tomography (CT) is a widespread and highly precise technique working in the energy range around 50-100 keV. For radiotherapy, however, the MeV energy range enables a better dose distribution. This gap between diagnosis and therapy can be overcome by the use of a modified CT machine in combination with heavy elements targeted to the tumour and used as photoelectric radiation enhancer. Materials and methods: The experimental setup consists of an X-ray optical module mounted at the exit of the X-ray tube of a clinical CT. The module converts the standard fan-shaped beam into a high intensity, monochromatized and focused beam. The radiation was characterized using an energy-dispersive detection system calibrated by synchrotron radiation and gel dosimetry. The photoelectric radiation enhancement for different elements was calculated and experimentally verified. Results: The X-ray optical module filters selectively the energy of the tungsten Kα-emission line (59.3 keV) with a full width at half maximum (FWHM) of 5 keV and focused the radiation onto a focal spot which coincides with the isocentre of the gantry. This results in a steep dose gradient at the centre of rotation qualified for locoregional radiation therapy. The photon energy of the quasi-monochromatic radiation agrees with the energy range of maximal photoelectric dose enhancement for gadolinium and iodine. Conclusion: An additional X-ray optical module optimized for targeted therapy and photoelectric dose enhancement allows the combination of diagnosis and radiotherapy on a clinical CT

Imaging-therapy computed tomography with quasi-monochromatic X-rays

Energy Technology Data Exchange (ETDEWEB)

Jost, Gregor [Bayer Schering Pharma AG, Contrast Media Research, Muellerstrasse 178, 13353 Berlin (Germany)], E-mail: gregor.jost@bayerhealthcare.com; Golfier, Sven [Bayer Schering Pharma AG, Contrast Media Research, Muellerstrasse 178, 13353 Berlin (Germany)], E-mail: sven.golfier@bayerhealthcare.com; Lawaczeck, Ruediger [Bayer Schering Pharma AG, Contrast Media Research, Muellerstrasse 178, 13353 Berlin (Germany)], E-mail: ruediger.lawaczeck@bayerhealthcare.com; Weinmann, Hanns-Joachim [Bayer Schering Pharma AG, Contrast Media Research, Muellerstrasse 178, 13353 Berlin (Germany)], E-mail: hanns-joachim.weinmann@bayerhealthcare.com; Gerlach, Martin [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany)], E-mail: martin.gerlach@ptb.de; Cibik, Levent [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany)], E-mail: levent.cibik@ptb.de; Krumrey, Michael [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany)], E-mail: michael.krumrey@ptb.de; Fratzscher, Daniel [Institute for Scientific Instruments GmbH, Rudower Chaussee 29/31, 12489 Berlin (Germany)], E-mail: Fratzscher@ifg-adlershof.de; Rabe, Johannis [Institute for Scientific Instruments GmbH, Rudower Chaussee 29/31, 12489 Berlin (Germany)], E-mail: Rabe@ifg-adlershof.de; Arkadiev, Vladimir [Institute for Scientific Instruments GmbH, Rudower Chaussee 29/31, 12489 Berlin (Germany)], E-mail: Arkadiev@ifg-adlershof.de; Haschke, Michael [Institute for Scientific Instruments GmbH, Rudower Chaussee 29/31, 12489 Berlin (Germany)], E-mail: Haschke@ifg-adlershof.de; Langhoff, Norbert [Institute for Scientific Instruments GmbH, Rudower Chaussee 29/31, 12489 Berlin (Germany)], E-mail: Langhoff@ifg-adlershof.de; Wedell, Reiner [Institut fuer angewandte Photonik e.V., Rudower Chaussee 29/31, 12489 Berlin (Germany)], E-mail: wedell-iap@ifg-adlershof.de (and others)

2008-12-15

Introduction: Computed tomography (CT) is a widespread and highly precise technique working in the energy range around 50-100 keV. For radiotherapy, however, the MeV energy range enables a better dose distribution. This gap between diagnosis and therapy can be overcome by the use of a modified CT machine in combination with heavy elements targeted to the tumour and used as photoelectric radiation enhancer. Materials and methods: The experimental setup consists of an X-ray optical module mounted at the exit of the X-ray tube of a clinical CT. The module converts the standard fan-shaped beam into a high intensity, monochromatized and focused beam. The radiation was characterized using an energy-dispersive detection system calibrated by synchrotron radiation and gel dosimetry. The photoelectric radiation enhancement for different elements was calculated and experimentally verified. Results: The X-ray optical module filters selectively the energy of the tungsten K{alpha}-emission line (59.3 keV) with a full width at half maximum (FWHM) of 5 keV and focused the radiation onto a focal spot which coincides with the isocentre of the gantry. This results in a steep dose gradient at the centre of rotation qualified for locoregional radiation therapy. The photon energy of the quasi-monochromatic radiation agrees with the energy range of maximal photoelectric dose enhancement for gadolinium and iodine. Conclusion: An additional X-ray optical module optimized for targeted therapy and photoelectric dose enhancement allows the combination of diagnosis and radiotherapy on a clinical CT.

Incidents with hazardous radiation sources; Zwischenfaelle mit gefaehrlichen Strahlenquellen

Energy Technology Data Exchange (ETDEWEB)

Schoenhacker, Stefan [Bundesministerium fuer Inneres, Traiskirchen (Austria). Abt. 1/9 - Zivilschutzschule

2016-07-01

Incidents with hazardous radiation sources can occur in any country, even those without nuclear facilities. Preparedness for such incidents is supposed to fulfill globally agreed minimum standards. Incidents are categorized in incidents with licensed handling of radiation sources as for material testing, transport accidents of hazardous radiation sources, incidents with radionuclide batteries, incidents with satellites containing radioactive inventory, incidents wit not licensed handling of illegally acquired hazardous radiation sources. The emergency planning in Austria includes a differentiation according to the consequences: incidents with release of radioactive materials resulting in restricted contamination, incidents with release of radioactive materials resulting in local contamination, and incidents with the hazard of e@nhanced exposure due to the radiation source.

Photon activation therapy of RG2 glioma carrying Fischer rats using stable thallium and monochromatic synchrotron radiation.

Science.gov (United States)

Ceberg, Crister; Jönsson, Bo-Anders; Prezado, Yolanda; Pommer, Tobias; Nittby, Henrietta; Englund, Elisabet; Grafström, Gustav; Edvardsson, Anneli; Stenvall, Anna; Strömblad, Susanne; Wingårdh, Karin; Persson, Bertil; Elleaume, Hélène; Baldetorp, Bo; Salford, Leif G; Strand, Sven-Erik

2012-12-21

75 RG2 glioma-carrying Fischer rats were treated by photon activation therapy (PAT) with monochromatic synchrotron radiation and stable thallium. Three groups were treated with thallium in combination with radiation at different energy; immediately below and above the thallium K-edge, and at 50 keV. Three control groups were given irradiation only, thallium only, or no treatment at all. For animals receiving thallium in combination with radiation to 15 Gy at 50 keV, the median survival time was 30 days, which was 67% longer than for the untreated controls (p = 0.0020) and 36% longer than for the group treated with radiation alone (not significant). Treatment with thallium and radiation at the higher energy levels were not effective at the given absorbed dose and thallium concentration. In the groups treated at 50 keV and above the K-edge, several animals exhibited extensive and sometimes contra-lateral edema, neuronal death and frank tissue necrosis. No such marked changes were seen in the other groups. The results were discussed with reference to Monte Carlo calculated electron energy spectra and dose enhancement factors.

Discriminating electromagnetic radiation based on angle of incidence

Science.gov (United States)

Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

2015-06-16

The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

Nonlinear real index of refraction variations of a gas medium due to a monochromatic radiation near resonance

International Nuclear Information System (INIS)

Vasconcellos, J.I.C.

1982-01-01

The nonlinear real index of refraction variations of a gas medium due to a strong monochromatic radiation causing saturation effects is calculated. The gas is supposed to be composed of two-level molecules with which the external field is nearly resonant. It is assumed homogeneous (hard collisions, spontaneous decay) and inhomogeneous (Doppler effect) broadening mechanisms acting on the real index of refraction of the medium. The nonlinear dispersion of the medium is studied as a function of the detuning frequencies, saturation conditions and for various ratios between the homogeneous and inhomogeneous linewidths. In particular, the modification of the index of refraction due to saturation effects are emphasized. (Author) [pt

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

Indian Academy of Sciences (India)

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

Spectroscopic and bolometric measurements of radiation loss in DIVA

International Nuclear Information System (INIS)

Shiho, Makoto; Odajima, Kazuo; Sugie, Tatsuo; Maeda, Hikosuke; Kasai, Satoshi

1977-11-01

Radiation loss due to low- and high-z impurities in DIVA (JFT-2a) was measured by means of a calibrated 3m grazing incidence vacuum monochromater and a calibrated pyroelectric detector. The following results were obtained: 1) Radiation loss power due to low-z impurities becomes insignificant by using clean surfaces for the vacuum wall. 2) Radiation loss power due to pseudo continuum from high-z impurities has influence on the energy balance of the confined plasma. 3) The divertor reduces the radiation loss by a factor of about 3. (auth.)

Computed tomography for light materials using a monochromatic X-ray beam produced by parametric X-ray radiation

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, Y., E-mail: yahayak@lebra.nihon-u.ac.jp [Laboratory for Electron Beam Research and Application, Nihon University, Narashinodai 7-24-1, Funabashi 274-8501 (Japan); Hayakawa, K.; Inagaki, M. [Laboratory for Electron Beam Research and Application, Nihon University, Narashinodai 7-24-1, Funabashi 274-8501 (Japan); Kaneda, T. [Nihon University School of Dentistry at Matsudo, Sakaecho-Nishi 2-870-1, Matsudo 271-8587 (Japan); Nakao, K.; Nogami, K. [Laboratory for Electron Beam Research and Application, Nihon University, Narashinodai 7-24-1, Funabashi 274-8501 (Japan); Sakae, T. [Nihon University School of Dentistry at Matsudo, Sakaecho-Nishi 2-870-1, Matsudo 271-8587 (Japan); Sakai, T.; Sato, I. [Laboratory for Electron Beam Research and Application, Nihon University, Narashinodai 7-24-1, Funabashi 274-8501 (Japan); Takahashi, Y. [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Oho, Tsukuba 305-8501 (Japan); Tanaka, T. [Laboratory for Electron Beam Research and Application, Nihon University, Narashinodai 7-24-1, Funabashi 274-8501 (Japan)

2013-08-15

Computed tomography (CT) for light materials such as soft biological tissues was performed using a monochromatic X-ray beam provided by a parametric X-ray radiation (PXR) source at the Laboratory for Electron Beam Research and Application (LEBRA) of Nihon University. Using a high-efficiency flat panel detector (FPD), each projection image for CT was taken with exposure times of 5 or 10 s, and 60–360 projection images in each run were obtained with total measurement time of 5 min to 1 h. CT images were obtained from the projection images using the conventional calculation method. The typical tomograms obtained had sharp outlines, which are likely attributable to the propagation-based phase contrast.

Improved sensitivity in patients with peripheral neuropathy: effects of monochromatic infrared photo energy.

Science.gov (United States)

DeLellis, Salvatore L; Carnegie, Dale H; Burke, Thomas J

2005-01-01

The medical records of 1,047 patients (mean age, 73 years) with established peripheral neuropathy were examined to determine whether treatment with monochromatic infrared photo energy was associated with increased foot sensitivity to the 5.07 Semmes-Weinstein monofilament. The peripheral neuropathy in 790 of these patients (75%) was due to diabetes mellitus. Before treatment with monochromatic infrared photo energy, of the ten tested sites (five on each foot), a mean +/- SD of 7.9 +/- 2.4 sites were insensitive to the 5.07 Semmes-Weinstein monofilament, and 1,033 patients exhibited loss of protective sensation. After treatment, the mean +/- SD number of insensate sites on both feet was 2.3 +/- 2.4, an improvement of 71%. Only 453 of 1,033 patients (43.9%) continued to have loss of protective sensation after treatment. Therefore, monochromatic infrared photo energy treatment seems to be associated with significant clinical improvement in foot sensation in patients, primarily Medicare aged, with peripheral neuropathy. Because insensitivity to the 5.07 Semmes-Weinstein monofilament has been reported to be a major risk factor for diabetic foot wounds, the use of monochromatic infrared photo energy may be associated with a reduced incidence of diabetic foot wounds and amputations.

Three-dimensional monochromatic x-ray CT

Science.gov (United States)

Saito, Tsuneo; Kudo, Hiroyuki; Takeda, Tohoru; Itai, Yuji; Tokumori, Kenji; Toyofuku, Fukai; Hyodo, Kazuyuki; Ando, Masami; Nishimura, Ktsuyuki; Uyama, Chikao

1995-08-01

In this paper, we describe a 3D computed tomography (3D CT) using monochromatic x-rays generated by synchrotron radiation, which performs a direct reconstruction of 3D volume image of an object from its cone-beam projections. For the develpment of 3D CT, scanning orbit of x-ray source to obtain complete 3D information about an object and corresponding 3D image reconstruction algorithm are considered. Computer simulation studies demonstrate the validities of proposed scanning method and reconstruction algorithm. A prototype experimental system of 3D CT was constructed. Basic phantom examinations and specific material CT image by energy subtraction obtained in this experimental system are shown.

IRID: specifications for the Ionising Radiations Incident Database

International Nuclear Information System (INIS)

Thomas, G.O.; Croft, J.R.; Williams, M.K.; McHugh, J.O.

1996-01-01

Technologies that make use of ionising radiations are widespread. They provide many benefits but, as with other technologies, the use of ionising radiations carries with it the potential for incidents and accidents. Their severity can vary from the trivial to the fatal and may involve substantial economic penalties. In order to minimise the number of incidents and their consequences it is important that there is a mechanism to learn the lessons from those that do occur. To help pursue this objective the National Radiological Protection Board, the Health and Safety Executive and the Environment Agency have established a national Ionising Radiations Incident Database (IRID) to cover radiation incidents in industry, medicine, research and teaching. This publication details the specifications for IRID and its methods of operation. All information in the database will be unattributable and names of persons or organisations will not be included. It is a personal computer based system with 24 fields to categorise an incident, including a text field that will provide a description of the incident giving the causes, consequences, follow-up actions and lessons to be learned. These descriptions will be used in subsequent publications to provide feedback to the users. (UK)

Curved crystal x-ray optics for monochromatic imaging with a clinical source.

Science.gov (United States)

Bingölbali, Ayhan; MacDonald, C A

2009-04-01

Monochromatic x-ray imaging has been shown to increase contrast and reduce dose relative to conventional broadband imaging. However, clinical sources with very narrow energy bandwidth tend to have limited intensity and field of view. In this study, focused fan beam monochromatic radiation was obtained using doubly curved monochromator crystals. While these optics have been in use for microanalysis at synchrotron facilities for some time, this work is the first investigation of the potential application of curved crystal optics to clinical sources for medical imaging. The optics could be used with a variety of clinical sources for monochromatic slot scan imaging. The intensity was assessed and the resolution of the focused beam was measured using a knife-edge technique. A simulation model was developed and comparisons to the measured resolution were performed to verify the accuracy of the simulation to predict resolution for different conventional sources. A simple geometrical calculation was also developed. The measured, simulated, and calculated resolutions agreed well. Adequate resolution and intensity for mammography were predicted for appropriate source/optic combinations.

High resolution monochromatic X-ray imaging system based on spherically bent crystals

International Nuclear Information System (INIS)

Aglitskiy, Y.; Lehecka, T.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Brown, C. M.; Seely, J.; Feldman, U.; Holland, G.

1997-01-01

We have developed a new X-ray imaging system based on spherically curved crystals. It is designed and used for diagnostics of targets ablatively accelerated by the Nike KrF laser. The imaging system is used for plasma diagnostics of the main target and for characterization of potential backlighters. A spherically curved quartz crystal (2d=6.687 A, R=200 mm) is used to produce monochromatic backlit images with the He-like Si resonance line (1865 eV) as the source of radiation. The spatial resolution of the X-ray optical system is 3-4 μm. Time resolved backlit monochromatic images of CH planar targets driven by the Nike facility have been obtained with 6-7 μm spatial resolution

Monochromatic X-ray probing of a superdense plasma

International Nuclear Information System (INIS)

Pikuz, S.A.; Shelkovenko, T.A.; Romanova, V.M.; Faenov, A.Ya.; Dyakin, V.A.; Pikuz, T.A.

1995-01-01

Investigation results are presented of the superdense plasma of an exploding wire by means of a new scheme of X-ray monochromatic probing. The scheme permits not only to obtain the shadow images of bright plasma objects in separate spectral lines with a high spatial resolution but and to lower requirements to a radiation source. Experimental results confirm existence of a small-dense plasma coronae, appeared during the initial stage of a discharge through a wire, and a dense core, existing at the pinch axis in the discharge process. 13 refs.; 3 figs

Using mortality data to estimate radiation effects on breast cancer incidence

International Nuclear Information System (INIS)

Hoel, D.G.; Dinse, G.E.

1990-01-01

In this paper we combine Japanese data on radiation exposure and cancer mortality with U.S. data on cancer incidence and lethality to estimate the effects of ionizing radiation on cancer incidence. The analysis is based on the mathematical relationship between the mortality rate and the incidence and lethality rates, as well as on statistical models that relate Japanese incidence rates to U.S. incidence rates and radiation risk factors. Our approach assumes that the risk of death from causes other than the cancer does not depend on whether or not the cancer is present, and among individuals with the cancer, the risk of death attributable to the cancer is the same in Japan and the U.S. and is not affected by radiation exposure. In particular, we focus on the incidence of breast cancer in Japanese women and how this incidence is affected by radiation risk factors. The analysis uses Japanese exposure and mortality data from the Radiation Effects Research Foundation study of atomic bomb survivors and U.S. incidence and lethality data from the Surveillance, Epidemiology, and End Results Registry. Even without Japanese incidence data, we obtain reasonable estimates of the incidence of breast cancer in unexposed Japanese women and identify the radiation risk factors that affect this incidence. Our analysis demonstrates that the age at exposure is an important risk factor, but that the incidence of breast cancer is not affected by the city of residence (Nagasaki versus Hiroshima) or the time since exposure

Prostate cancer incidence in Australia correlates inversely with solar radiation.

Science.gov (United States)

Loke, Tim W; Seyfi, Doruk; Sevfi, Doruk; Khadra, Mohamed

2011-11-01

What's known on the subject? and What does the study add? Increased sun exposure and blood levels of vitamin D have been postulated to be protective against prostate cancer. This is controversial. We investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia, and found a lower incidence in regions receiving more sunlight. In landmark ecological studies, prostate cancer mortality rates have been shown to be inversely related to ultraviolet radiation exposure. Investigators have hypothesised that ultraviolet radiation acts by increasing production of vitamin D, which inhibits prostate cancer cells in vitro. However, analyses of serum levels of vitamin D in men with prostate cancer have failed to support this hypothesis. This study has found an inverse correlation between solar radiation and prostate cancer incidence in Australia. Our population (previously unstudied) represents the third group to exhibit this correlation. Significantly, the demographics and climate of Australia differ markedly from those of previous studies conducted on men in the United Kingdom and the United States. • To ascertain if prostate cancer incidence rates correlate with solar radiation among non-urban populations of men in Australia. • Local government areas from each state and territory were selected using explicit criteria. Urban areas were excluded from analysis. • For each local government area, prostate cancer incidence rates and averaged long-term solar radiation were obtained. • The strength of the association between prostate cancer incidence and solar radiation was determined. • Among 70 local government areas of Australia, age-standardized prostate cancer incidence rates for the period 1998-2007 correlated inversely with daily solar radiation averaged over the last two decades. •  There exists an association between less solar radiation and higher prostate cancer incidence in Australia. © 2011 THE AUTHORS. BJU

High resolution monochromatic X-ray imaging system based on spherically bent crystals

International Nuclear Information System (INIS)

Aglitskiy, Y.; Lehecka, T.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Brown, C.M.; Seely, J.; Feldman, U.; Holland, G.

1997-01-01

We have developed a new X-ray imaging system based on spherically curved crystals. It is designed and used for diagnostics of targets ablatively accelerated by the Nike KrF laser [1,2]. The imaging system is used for plasma diagnostics of the main target and for characterization of potential backlighters. A spherically curved quartz crystal (2d=6.687 Angstrom, R=200mm) is used to produce monochromatic backlit images with the He-like Si resonance line (1865 eV) as the source of radiation. The spatial resolution of the X-ray optical system is 3 endash 4 μm. Time resolved backlit monochromatic images of CH planar targets driven by the Nike facility have been obtained with 6 endash 7 μm spatial resolution. copyright 1997 American Institute of Physics

Modification of radiation-induced murine thymic lymphoma incidence by curcumin

International Nuclear Information System (INIS)

Dange, P.S.; Yadav, H.D.; Kumar, Vimalesh; Bhilwade, H.N.; Pandey, B.N.; Sarma, H.D.

2017-01-01

Curcumin is a known antioxidant, preventing radiation damage including carcinogenesis. However, concentration and feeding schedule of curcumin in modification of radiation induced thymic lymphoma incidence in vivo model has not been studied. We report here modification of incidence of γ-radiation-induced thymic lymphoma in mice fed with different doses of curcumin (0.05 to 1 %) in diet. Results: Female Swiss mice (6-8 weeks) fed with normal diet and exposed to 3 Gy whole body "6"0Co γ-irradiation (WBI) showed 85 % incidence of thymic lymphoma (TL) at 120 days post-irradiation. A concentration of 1 % curcumin was found the most effective in TL incidence prevention than other fed concentrations. The TL incidence was remarkably reduced when curcumin was fed to the mice before than after the radiation exposure. These results suggest modification of TL incidence by curcumin in irradiated mice involving DNA damage and apoptotic death mechanisms

High-resolution monochromatic x-ray imaging system based on spherically bent crystals

International Nuclear Information System (INIS)

Aglitskiy, Y.; Lehecka, T.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Brown, C.M.; Seely, J.; Feldman, U.; Holland, G.

1998-01-01

We have developed an improved x-ray imaging system based on spherically curve crystals. It is designed and used for diagnostics of targets ablatively accelerated by the Nike KrF laser. A spherically curved quartz crystal (2d=6.687 Angstrom, R=200 mm) has been used to produce monochromatic backlit images with the He-like Si resonance line (1865 eV) as the source of radiation. The spatial resolution of the x-ray optical system is 1.7 μm in selected places and 2 - 3 μm over a larger area. Time-resolved backlit monochromatic images of polystyrene planar targets driven by the Nike facility have been obtained with a spatial resolution of 2.5 μm in selected places and 5 μm over the focal spot of the Nike laser. copyright 1998 Optical Society of America

Photosensitized inactivation of DNA by monochromatic 334-nm radiation in the presence of 2-thiouracil: genetic activity and backbone breaks

International Nuclear Information System (INIS)

Peak, M.J.; Ito, A.; Peak, J.G.; Foote, C.S.

1988-01-01

Monochromatic 334-nm radiation delivered under aerobic conditions inactivates the genetic activity (ability to transform auxotrophic recipient cells to nutritional prototrophy) of isolated transforming Bacillus subtilis DNA. The presence of superoxide dismutase (SOD), catalase, and mannitol reduces the 334-nm inactivation. The rate of inactivation of the genetic activity by 334-nm radiation is enhanced fivefold by the sensitizer 2-thiouracil (s 2 Ura). This enhancement is substantially reversed when the irradiations are performed in the presence of mannitol, and, to a lesser extent, SOD. Catalase slightly reduces the s 2 Ura enhancement of 334-nm inactivation of transforming activity. Backbone breaks induced in the same DNA by aerobic 334-nm radiation were also enhanced markedly by the presence of s 2 Ura; this enhancement was reversed by the presence of mannitol and, to a lesser extent, SOD during irradiation. Catalase had no effect upon s 2 Ura-enhanced, 334-nm-induced SSBs. Whereas DNA breakage may be responsible for a portion of the inactivation of the DNA by the photosensitized reaction between s 2 Ura and 334-nm radiation, it is not the only inactivating lesion, because the yield of SSBs per lethal hit per unit length of DNA is not constant for all the irradiation conditions studied. (author)

L-shell radiative transition rates by selective synchrotron ionization

International Nuclear Information System (INIS)

Bonetto, R D; Carreras, A C; Trincavelli, J; Castellano, G

2004-01-01

Relative L-shell radiative transition rates were obtained for a number of decays in Gd, Dy, Er, Yb, Hf, Ta and Re by means of a method for refining atomic and experimental parameters involved in the spectral analysis of x-ray irradiated samples. For this purpose, pure samples were bombarded with monochromatic synchrotron radiation tuning the incident x-ray energy in order to allow selective ionization of the different atomic shells. The results presented are compared to experimental and theoretical values published by other authors. A good general agreement was found and some particular discrepancies are discussed

Comment on "Collision monochromatization in e+e- colliders"

Science.gov (United States)

Shatilov, D.

2018-02-01

Bogomyagkov and Levichev [Phys. Rev. Accel. Beams 20, 051001 (2017), 10.1103/PhysRevAccelBeams.20.051001] have recently reported on monochromatization in collision schemes with crossing angle. From their results, in particular, it may seem that: (1) horizontal dispersion at the IP can provide monochromatization factor Λ ≫1 while retaining Piwinski angle ϕ >1 , (2) production rate in such a scheme for FCC-ee at 62.5 GeV can be larger than that in the nominal crab waist collision, and (3) strong rf focusing can be used for monochromatization purposes. We demonstrate here that the first two statements are not correct, and the last one is very doubtful.

Analysis of monochromatic signals by using data from the detector of Allegro gravitational waves

International Nuclear Information System (INIS)

Oliveira, Fernanda Gomes de

2010-01-01

The present work is developed in the searching for monochromatic gravitational waves signals in ALLEGRO's data. We have two procedures for data analysis based on the periodogram of Welch, which a method for the detection of monochromatic signals in the middle of noise which basically makes power spectrum estimates using averaged modified periodograms. By using this method it was possible to obtain a power spectrum for the data which reinforce peaks due to monochromatic signals. The two procedures of analysis for the years 1997 and 1999, were focused on monitoring a peak that appears in the spectral density of ALLEGRO's detector, so called 'mystery mode' (near 887 Hz). We look for variations in the frequency of the mystery mode that agree with the variation of the Doppler effect. In the rst analysis we have used by the variation of daily and annual Doppler shift. For the second one, we have only searched annual Doppler shift. We have applied the periodogram of Welch in both tests in the raw data of the detector in the search for a real signal and we found some peaks that can be candidates of gravitational radiation only the second analysis. In order to test the method we used in both analysis a simulated gravitational wave signal modulated by the Doppler effect injected in the data. We detected in both methods the artificial signal of GW simulated. Therefore we have reason to conclude that both methods are efficient in the search for monochromatic signals. (author)

Inhibition of motility in the cyanobacterium, Phormidium uncinatum, by solar and monochromatic UV irradiation

International Nuclear Information System (INIS)

Häder, D.P.; Watanabe, M.; Furuya, M.

1986-01-01

The effect of solar radiation and monochromatic UV radiation on the motility of the filamentous cyanobacterium Phormidium uncinatum was determined. Solar radiation (mid-day, in midsummer at a location near Lisboa, Portugal) was found to impair motility within about 30 min. This effect is neither a result of a temperature increase nor of visible light. The spectral sensitivity determined using the Okazaki Largé Spectrograph shows the maximal effectiveness of radiation of ≤300 nm. The short time requirement for the response and the lack of any photoreactivation of motility argues against DNA being the UV target. Investigations using reagents diagnostic of superoxide free radicals and singlet oxygen failed to confirm the involvement of photodynamic effects as the molecular mechanism causing UV inhibition of motility

Monochromatic neutrino beams

International Nuclear Information System (INIS)

Bernabeu, Jose; Burguet-Castell, Jordi; Espinoza, Catalina; Lindroos, Mats

2005-01-01

In the last few years spectacular results have been achieved with the demonstration of non vanishing neutrino masses and flavour mixing. The ultimate goal is the understanding of the origin of these properties from new physics. In this road, the last unknown mixing [U e3 ] must be determined. If it is proved to be non-zero, the possibility is open for Charge Conjugation-Parity (CP) violation in the lepton sector. This will require precision experiments with a very intense neutrino source. Here a novel method to create a monochromatic neutrino beam, an old dream for neutrino physics, is proposed based on the recent discovery of nuclei that decay fast through electron capture. Such nuclei will generate a monochromatic directional neutrino beam when decaying at high energy in a storage ring with long straight sections. We also show that the capacity of such a facility to discover new physics is impressive, so that fine tuning of the boosted neutrino energy allows precision measurements of the oscillation parameters even for a [U e3 ] mixing as small as 1 degree. We can thus open a window to the discovery of CP violation in neutrino oscillations

The management of radiation treatment error through incident learning

International Nuclear Information System (INIS)

Clark, Brenda G.; Brown, Robert J.; Ploquin, Jodi L.; Kind, Anneke L.; Grimard, Laval

2010-01-01

Purpose: To assess efficacy of an incident learning system in the management of error in radiation treatment. Materials and methods: We report an incident learning system implementation customized for radiation therapy where any 'unwanted or unexpected change from normal system behaviour that causes or has the potential to cause an adverse effect to persons or equipment' is reported, investigated and learned from. This system thus captures near-miss (potential) and actual events. Incidents are categorized according to severity, type and origin. Results: Our analysis spans a period of 3 years with an average accrual of 11.6 incidents per week. We found a significant reduction in actual incidents of 28% and 47% in the second and third year when compared to the first year (p < 0.001), which we attribute to the many interventions prompted by the analysis of incidents reported. We also saw a similar significant reduction in incidents generated at the treatment unit correlating with the introduction of direct treatment parameter transfer and electronic imaging (p < 0.001). Conclusions: Implementation of an incident learning system has helped us to establish a just environment where all staff members report deviations from normal system behaviour and thus generate evidence to initiate safety improvements.

Medical management of three workers following a radiation exposure incident

International Nuclear Information System (INIS)

House, R.A.; Sax, S.E.; Rumack, E.R.; Holness, D.L.

1992-01-01

The medical management of three individuals involved in an exposure incident to whole-body radiation at a nuclear generating plant of a Canadian electrical utility is described. The exposure incident resulted in the two highest whole-body radiation doses ever received in a single event by workers in a Canadian nuclear power plant. The individual whole-body doses (127.4 mSv, 92.0 mSv, 22.4 mSv) were below the threshold for acute radiation sickness but the exposures still presented medical management problems related to assessment and counseling. Serial blood counting and lymphocyte cytogenetic analysis to corroborate the physical dosimetry were performed. All three employees experienced somatic symptoms due to stress and one employee developed post-traumatic stress disorder. This incident indicates that there is a need in such radiation exposure accidents for early and continued counseling of exposed employees to minimize the risk of development of stress-related symptoms

Medical management of three workers following a radiation exposure incident

Energy Technology Data Exchange (ETDEWEB)

House, R.A.; Sax, S.E.; Rumack, E.R.; Holness, D.L. (Department of Occupational and Environmental Health, St. Michael' s Hospital, Toronto, Ontario (Canada))

1992-01-01

The medical management of three individuals involved in an exposure incident to whole-body radiation at a nuclear generating plant of a Canadian electrical utility is described. The exposure incident resulted in the two highest whole-body radiation doses ever received in a single event by workers in a Canadian nuclear power plant. The individual whole-body doses (127.4 mSv, 92.0 mSv, 22.4 mSv) were below the threshold for acute radiation sickness but the exposures still presented medical management problems related to assessment and counseling. Serial blood counting and lymphocyte cytogenetic analysis to corroborate the physical dosimetry were performed. All three employees experienced somatic symptoms due to stress and one employee developed post-traumatic stress disorder. This incident indicates that there is a need in such radiation exposure accidents for early and continued counseling of exposed employees to minimize the risk of development of stress-related symptoms.

An evaluation of the effect of natural background radiation on cancer incidence

International Nuclear Information System (INIS)

Cohen, Jerry J.

1978-01-01

Previous studies on the relationship between levels of natural background radiation and cancer incidence indicate no significant correlation. This observation is shown to be consistent with certain predicted effect levels of ionizing radiation on malignancy production (BEIR, ICRP). Other theoretical predictions on the effects of ionizing radiation indicate induction rates to be as high as 8 x 10 -3 cancers/person-rem. Assuming this factor were correct, then roughly one-half of the cancer incidence in the USA could be attributed to exposure to natural background radiation. By statistically testing various hypothetically assigned cancer induction rates against observed data, it is possible to develop a probabilistic perspective on the cause-effect relationship. Tests have been performed using normalized (by age, death rate, etc.) cancer incidence by state against levels of background radiation. This evaluation allows for the determination of the probability of observing the actual data given that the hypotheses were correct. Graphic relationships between hypothetically assigned radiation induced cancer rates vs. the probability of observing the actual incidence are developed and presented. It is shown that if the cancer induction rate were in excess of ∼10 -3 cancers/person-rem, it would be highly improbable that there would, in fact, be a lack of correlation between the rates of natural background radiation and cancer incidence. (author)

First Sub-arcsecond Collimation of Monochromatic Neutrons

Energy Technology Data Exchange (ETDEWEB)

Wagh, Apoorva G; Abbas, Sohrab; Treimer, Wolfgang, E-mail: nintsspd@barc.gov.in

2010-11-01

We have achieved the tightest collimation to date of a monochromatic neutron beam by diffracting neutrons from a Bragg prism, viz. a single crystal prism operating in the vicinity of Bragg incidence. An optimised silicon {l_brace}111{r_brace} Bragg prism has collimated 5.26A neutrons down to 0.58 arcsecond. In conjunction with a similarly optimised Bragg prism analyser of opposite asymmetry, this ultra-parallel beam yielded a 0.62 arcsecond wide rocking curve. This beam has produced the first SUSANS spectrum in Q {approx} 10{sup -6} A{sup -1} range with a hydroxyapatite casein protein sample and demonstrated the instrument capability of characterising agglomerates upto 150 {mu}m in size. The super-collimation has also enabled recording of the first neutron diffraction pattern from a macroscopic grating of 200 {mu}m period. An analysis of this pattern yielded the beam transverse coherence length of 175 {mu}m (FWHM), the greatest achieved to date for A wavelength neutrons.

The cryogenic source of slow monochromatic positrons

International Nuclear Information System (INIS)

Meshkov, I.N.; Pavlov, V.N.; Sidorin, A.O.; Yakovenko, S.L.

2008-01-01

The cryogenic source of slow monochromatic positrons based on the 22 Na isotope has been designed and constructed at JINR. Positrons emitted from radioactive source 22 Na have a very broad energy spectrum up to 0.5 MeV. To generate monochromatic beam of slow positrons the solid neon is used as a moderator. The solid neon allows forming slow positron beam of the energy of 1.2 eV at the spectrum width of 1 eV. The efficiency of moderation is 1 % of total positron flux

Environmental exposure to ionizing radiation and childhood leukaemia incidence

International Nuclear Information System (INIS)

Evrard, Anne-Sophie

2006-01-01

This thesis aimed at providing an epidemiological approach of the hypothesis of the existence of an association between environmental exposure to ionizing radiation and childhood leukaemia incidence. From 1990 to 2001, 5,330 cases of acute leukaemia were registered by the French National Registry of Childhood Leukemia and Lymphoma in children under 15 years of age and living in mainland France at the time of diagnosis. Indoor radon concentration was estimated using 13,240 measurements carried out by the Institute for Radiation Protection and Nuclear Safety (IRSN), and covering the whole country. Exposure to terrestrial gamma radiation was based on continuous measurements, using thermoluminescent dosimeters, at about 1,000 sites covering the whole of France, in order to monitor the level of environmental radioactivity in France. Analyses were conducted using Poisson regressions, including ecological co-variates, at the level of the 'Departments' (95 administrative geographical units in France). A significant positive ecological association between indoor radon concentration and the incidence of acute myeloid leukaemia was evidenced (SIR=1.19 per 100 Bq/m 3 - 95% confidence interval=[1.03-1.38]) and remained significant in multivariate regression analyses including exposure to terrestrial gamma radiation and/or some ecological co-variates. Conversely, there was no evidence of an ecological association between exposure to terrestrial gamma radiation and childhood leukaemia incidence. The epidemiological studies of the incidence of childhood leukaemia around nuclear sites analyzed incidence with respect to the distance from the plants, without considering any information on the levels or geographic distribution of the radiation dose due to discharges from the plants. The present study investigated for the first time the incidence of childhood leukaemia around French nuclear installations using a geographic zoning based on estimated doses due to gaseous

RADIATION CONTAMINATION INCIDENT AT ISOLDE

CERN Multimedia

2000-01-01

On 27 June 2000 three specialists were investigating a problem with the extraction electrode of the high-resolution separator (HRS) in Isolde. Whilst using an endoscope in order to have a closer look at the interior, they came into contact with radioactive dust and became contaminated. The level of contamination was low and the radiation dose received by the 3 persons was far below the effective dose limit given in the CERN Radiation Safety Manual and in the regulations of the Host States.According to the usual procedure, the Director General has set up a Fact-Finding Group and an Accident Board in order to advise him on the steps and decisions tobe taken following this incident and in particular to avoid a recurrence.

Effect of the time spent by the photon in the absorbed state on the time-dependent transfer of radiation

International Nuclear Information System (INIS)

Rao, D.M.; Rangarajan, K.E.; Peraiah, A.

1990-01-01

The time-dependent transfer equation is derived for a two-level atomic model which takes both bound-bound and bound-free transitions into account. A numerical scheme is proposed for solving the monochromatic time-dependent transfer equation when the time spent by the photon in the absorbed state is significant. The method can be easily extended to solve the problem of time-dependent line formation of the bound-free continuum. It is used here to study three types of boundary conditions of the incident radiation incident on a scattering atmosphere. The quantitative results show that the relaxation of the radiation field depends on the optical depth of the medium and on the ray's angle of emergence. 21 refs

Comment on “Collision monochromatization in e^{+}e^{-} colliders”

Directory of Open Access Journals (Sweden)

D. Shatilov

2018-02-01

Full Text Available Bogomyagkov and Levichev [Phys. Rev. Accel. Beams 20, 051001 (2017PRABCJ2469-988810.1103/PhysRevAccelBeams.20.051001] have recently reported on monochromatization in collision schemes with crossing angle. From their results, in particular, it may seem that: (1 horizontal dispersion at the IP can provide monochromatization factor Λ≫1 while retaining Piwinski angle ϕ>1, (2 production rate in such a scheme for FCC-ee at 62.5 GeV can be larger than that in the nominal crab waist collision, and (3 strong rf focusing can be used for monochromatization purposes. We demonstrate here that the first two statements are not correct, and the last one is very doubtful.

Calorie restriction reduces the incidence of radiation-induced myeloid leukemia and spontaneous tumor

International Nuclear Information System (INIS)

Yoshida, Kazuko

1999-01-01

The host-defense mechanisms against cancers are known to be modulated by changing the environmental factor(s). The spontaneous incidence of myeloid leukemia is about 1% in C3H/He mice, and the incidence increases up to 23.3% when a single dose of radiation, 3 Gy X-ray, is exposed to a whole-body. Since calorie restriction was known to reduce the incidence of spontaneous tumors, a question as to whether such radiation induced-increase of myeloid leukemia would be also decreased by calorie restriction, was aimed to answer to elucidate possible mechanism of radiation-induced myeloid leukemia. By the calorie restriction, the incidence of myeloid leukemia was significantly decreased; it was reduced to 7.9% and 10.7% when restriction was started before (6 weeks old) and after (10 weeks old) irradiation, respectively. In addition, the latent period of the myeloid leukemia in the groups for calorie restriction was significantly extended at a greater extent as compared with the control diet groups. Number of hematopoietic stem cells, the possible target cells for radiation-induced leukemias, in the groups for the calorie restriction demonstrated a significant decrease, especially in the spleen, as compared with that in the control, when the evaluation was made at the time of radiation exposure. Then, we examined whether the decreased number of target cells at the time of exposure is caused by the reduction of radiation-induced myeloid leukemia with caloric restriction. The third restricted groups were fed 65 kcal diet (restricted diet) for the first 4 weeks i.e. from 6 weeks to 10 weeks old, then, the mice were fed with control diet after radiation. The incidence of myeloid leukemia in this group was slightly decreased but did not show statistically significance. Therefore, the caloric restriction seems to be more effective in the promotion stage than the initiation stage on radiation-induced leukemogenesis. It is well known that C3H/He mice develop hepatoma spontaneously

Enhancing monochromatic multipole emission by a subwavelength enclosure of degenerate Mie resonances

KAUST Repository

Zhao, Jiajun

2017-07-06

Sound emission is inefficient at low frequencies as limited by source size. This letter presents enhancing emission of monochromatic monopole and multipole sources by enclosing the source with a subwavelength circular enclosure filled of an anisotropic material of a low radial sound speed. The anisotropy is associated with an infinite tangential density along the azimuth. Numerical simulations show that emission gain is produced at frequencies surrounding degenerate Mie resonant frequencies of the enclosure, and meanwhile the radiation directivity pattern is well preserved. The degeneracy is theoretically analyzed. A realization of the material is suggested by using a space-coiling structure.

A versatile lattice for a tau-charm factory that includes a monochromatization scheme

International Nuclear Information System (INIS)

Faus-Golfe, A.; Le Duff, J.

1992-02-01

A double ring system with multibunch scheme and high luminosity is discussed. An attempt for beam monochromatization at the crossing point was made by increasing the vertical bending angle, and it succeeded in providing a proper matching. The next step consisted of demonstrating that the new ring geometry that permits a monochromatization scheme could be returned and rematched to operate without monochromatization, allowing only relocation of quadrupoles and readjustment of their gradient in the sloping region. The results of this work are reported after a brief recall of the monochromatization scheme requirements. (K.A.) 10 refs., 13 figs., 2 tabs

Influence of radiation and non-radiation factors on pancreatic cancer incidence among Mayak PA workers

Energy Technology Data Exchange (ETDEWEB)

Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D. [Southern Ural Biophysics Institute (SUBI), Ozyorsk (Russian Federation); Syrchikov, V.A.; Grigoryeva, E.S. [Mayak Production Association (Mayak PA), Ozyorsk (Russian Federation)

2006-07-01

The finding of this nested case-control study suggests that high levels of 239 Pu incorporation (239 Pu body burden > 3.7), alcohol abuse and smoking were associated with increasing the risk of pancreatic cancer among Mayak PA workers chronically exposed to ionizing radiation. The contribution of non radiation factors (alcohol abuse and smoking) to pancreatic tumor incidence is greater (AR=51%) than 239 Pu incorporation kBq; AR = 7%). No significant effect of external gamma rays ({<=} 6.8 Gy), prior exposure to chemical agents, or chronic digestive diseases was found on the incidence of pancreatic tumor. Evaluation of the absorbed alpha-radiation pancreatic dose will permit to make more exact the 239 Pu risk estimation in the further extended study.

Influence of radiation and non-radiation factors on pancreatic cancer incidence among Mayak PA workers

International Nuclear Information System (INIS)

Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D.; Syrchikov, V.A.; Grigoryeva, E.S.

2006-01-01

The finding of this nested case-control study suggests that high levels of 239 Pu incorporation (239 Pu body burden > 3.7), alcohol abuse and smoking were associated with increasing the risk of pancreatic cancer among Mayak PA workers chronically exposed to ionizing radiation. The contribution of non radiation factors (alcohol abuse and smoking) to pancreatic tumor incidence is greater (AR=51%) than 239 Pu incorporation kBq; AR = 7%). No significant effect of external gamma rays (≤ 6.8 Gy), prior exposure to chemical agents, or chronic digestive diseases was found on the incidence of pancreatic tumor. Evaluation of the absorbed alpha-radiation pancreatic dose will permit to make more exact the 239 Pu risk estimation in the further extended study

Identifying Predictive Factors for Incident Reports in Patients Receiving Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Elnahal, Shereef M., E-mail: selnaha1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Blackford, Amanda [Department of Oncology Biostatistics, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Smith, Koren; Souranis, Annette N.; Briner, Valerie; McNutt, Todd R.; DeWeese, Theodore L.; Wright, Jean L.; Terezakis, Stephanie A. [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

2016-04-01

Purpose: To describe radiation therapy cases during which voluntary incident reporting occurred; and identify patient- or treatment-specific factors that place patients at higher risk for incidents. Methods and Materials: We used our institution's incident learning system to build a database of patients with incident reports filed between January 2011 and December 2013. Patient- and treatment-specific data were reviewed for all patients with reported incidents, which were classified by step in the process and root cause. A control group of patients without events was generated for comparison. Summary statistics, likelihood ratios, and mixed-effect logistic regression models were used for group comparisons. Results: The incident and control groups comprised 794 and 499 patients, respectively. Common root causes included documentation errors (26.5%), communication (22.5%), technical treatment planning (37.5%), and technical treatment delivery (13.5%). Incidents were more frequently reported in minors (age <18 years) than in adult patients (37.7% vs 0.4%, P<.001). Patients with head and neck (16% vs 8%, P<.001) and breast (20% vs 15%, P=.03) primaries more frequently had incidents, whereas brain (18% vs 24%, P=.008) primaries were less frequent. Larger tumors (17% vs 10% had T4 lesions, P=.02), and cases on protocol (9% vs 5%, P=.005) or with intensity modulated radiation therapy/image guided intensity modulated radiation therapy (52% vs 43%, P=.001) were more likely to have incidents. Conclusions: We found several treatment- and patient-specific variables associated with incidents. These factors should be considered by treatment teams at the time of peer review to identify patients at higher risk. Larger datasets are required to recommend changes in care process standards, to minimize safety risks.

Identifying Predictive Factors for Incident Reports in Patients Receiving Radiation Therapy

International Nuclear Information System (INIS)

Elnahal, Shereef M.; Blackford, Amanda; Smith, Koren; Souranis, Annette N.; Briner, Valerie; McNutt, Todd R.; DeWeese, Theodore L.; Wright, Jean L.; Terezakis, Stephanie A.

2016-01-01

Purpose: To describe radiation therapy cases during which voluntary incident reporting occurred; and identify patient- or treatment-specific factors that place patients at higher risk for incidents. Methods and Materials: We used our institution's incident learning system to build a database of patients with incident reports filed between January 2011 and December 2013. Patient- and treatment-specific data were reviewed for all patients with reported incidents, which were classified by step in the process and root cause. A control group of patients without events was generated for comparison. Summary statistics, likelihood ratios, and mixed-effect logistic regression models were used for group comparisons. Results: The incident and control groups comprised 794 and 499 patients, respectively. Common root causes included documentation errors (26.5%), communication (22.5%), technical treatment planning (37.5%), and technical treatment delivery (13.5%). Incidents were more frequently reported in minors (age <18 years) than in adult patients (37.7% vs 0.4%, P<.001). Patients with head and neck (16% vs 8%, P<.001) and breast (20% vs 15%, P=.03) primaries more frequently had incidents, whereas brain (18% vs 24%, P=.008) primaries were less frequent. Larger tumors (17% vs 10% had T4 lesions, P=.02), and cases on protocol (9% vs 5%, P=.005) or with intensity modulated radiation therapy/image guided intensity modulated radiation therapy (52% vs 43%, P=.001) were more likely to have incidents. Conclusions: We found several treatment- and patient-specific variables associated with incidents. These factors should be considered by treatment teams at the time of peer review to identify patients at higher risk. Larger datasets are required to recommend changes in care process standards, to minimize safety risks.

Investigation of absorbed radiation dose in refraction-enhanced breast tomosynthesis by a Laue case analyser

International Nuclear Information System (INIS)

Sato, H.; Ando, M.; Shimao, D.

2011-01-01

An early diagnosis system for breast cancer using refraction-enhanced breast tomosynthesis is under development. Tomograms of breast specimens based on refraction-contrast were demonstrated using the simplest shift-and-add tomosynthesis algorithm. Raw projection image data of breast specimens for tomosynthesis were acquired for a total of 51 views over an angle of 50 deg., in increments of 1 deg., by rotating the object. The incident X ray was monochromatic synchrotron radiation with 20 keV. The purpose of this study was to estimate the absorbed dose of a new X-ray imaging method. As breast cancer almost always arises in glandular breast tissue, the average absorbed dose in such glandular tissue should be measured to estimate the radiation risk associated with mammography. The absorbed dose of the mammary gland due to monochromatic X rays was calculated by the Monte Carlo method, and the optimal X ray energy range for refraction-enhanced breast tomosynthesis was investigated through actual measurements. Compared with the conventional method, it was found to be below one-sixth per inspection. (authors)

Angular dependence of the efficiency of the UV sensor polysulphone film

International Nuclear Information System (INIS)

Krins, A.; Bolsee, D.; Doerschel, B.; Gillotay, D.; Knuschke, P.

2000-01-01

The UV dose refers to the physical quantity radiant exposure, which is defined for a plane area element with fixed orientation in space and thus radiation intercepting this area element is weighted with the cosine of the angle of incidence. For this reason, a UV dosemeter also has to weight incoming radiation with the cosine of the angle of incidence. The angular dependence of the efficiency of polysulphone film was determined experimentally. The investigations were carried out with monochromatic UV radiation at three different wavelengths as well as with polychromatic radiation. Angles were varied between normal incidence and 70 deg. Within this range, the angular dependence of the efficiency of polysulphone film follows the cosine function. This behaviour is independent of the wavelength and applies for monochromatic as well as for polychromatic radiation. These experimental results are corroborated by earlier theoretical considerations. (author)

Optimizing Monochromatic Focusing on ThALES

Czech Academy of Sciences Publication Activity Database

Čermák, P.; Boehm, M.; Kulda, J.; Roux, S.; Hiess, A.; Steffens, P.; Šaroun, Jan

2014-01-01

Roč. 82, A (2014), SA026 ISSN 0031-9015 Institutional support: RVO:61389005 Keywords : Monte Carlo ray-tracing * inelastic neutron scattering * Triple-Axis spectrometer * monochromatic focusing Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.585, year: 2014

Monochromatic and identifiable photons used in photonuclear research

International Nuclear Information System (INIS)

Beil, Hans; Bergere, Roland.

1980-07-01

A general overview is given of the most common experimental procedures for the production and utilisation of monochromatic and (or) identifiable photon probes actually operational in 1979. Their basic characteristics, merits and drawbacks, together with their respective major domains of experimental physics to which they are usually applied, are also investigated. Methods for producing such monochromatic and (or) identifiable photon probes, with a continuously variable energy from a few MeV up till about 180 GeV, are treated in some detail. Some of the most promising future trends in the ulterior development of such electromagnetic probes are also mentioned

A Superpowerful Source of Far-Ultraviolet Monochromatic Radiation

International Nuclear Information System (INIS)

Ivanova, E.P.; Ivanov, A.L.

2005-01-01

In several independent experiments investigating the interaction between the optical field of an intense laser pulse and a xenon cluster beam, we recorded an anomalously high quantum yield of the plasma radiation in the region 10-15 nm. In several cases, the conversion efficiency into the hemisphere reached 10% of the pumping pulse energy. The nature of this phenomenon has not yet been adequately explained. A high conversion efficiency is shown to be possible when producing a plasma with optimal parameters for the amplification of spontaneous radiation on Ni-like xenon transitions to be generated. In a collisional-radiative model, we performed detailed atomic-kinetic calculations of the gains and radiation spectra on the transitions with λ ≅ 4, 10, and 11.3 nm and in the region 13-13.9 nm. For each transition, we determined the time dependences of the gains on plasma parameters. The theoretical and experimental values of the optimal plasma parameters and energy yields of the radiation are in close agreement. Using a theoretical model, we propose possible plasma pumping schemes to achieve the maximum yield of the intense, narrowly beamed soft X-ray radiation. At a pumping pulse repetition rate of 10 4 Hz, the output power for various Ni-like xenon transitions ranges from 100 to 5 x 10 3 W

The quasi-monochromatic photon beam used in photoneutron experiments from 20-120 MeV at the 600 MeV Saclay Linac

International Nuclear Information System (INIS)

Veyssiere, A.; Beil, H.; Bergere, R.; Carlos, P.; Fagot, J.; Lepretre, A.; Ahrens, J.

1979-01-01

A beam of 20-130 MeV positrons, with average intensities between 10 nA and 50 nA, is used at the 600 MeV Saclay Linac to create a quasi-monochromatic photon beam with a continuously variable energy. This beam was used to measure photoneutron cross sections and the corresponding photonuclear facility is first described. The computer-controlled methods, implemented to measure the energy spectrum and the emittance of the positron beam are described. The quasi-monochromatic photon lines are produced by the annihilation in flight of monoenergetic positrons in two annihilation radiators with different Z successively. The photon beam emission angle theta is shown to be the most critical parameter in the search for an optimum overall signal to background ratio for a specific photoneutron experiment. The choice of an angle theta approximately 4 0 is explained for absolute measurements of sigma(γ, xn) cross-sections, for which the used average intensities of monochromatic photons were thus purposely reduced to approximately 5 X 10 3 s -1 , with an energy resolution approximately 12%. (Auth.)

Phenomenological modelling of second cancer incidence for radiation treatment planning

International Nuclear Information System (INIS)

Pfaffenberger, Asja; Oelfke, Uwe; Schneider, Uwe; Poppe, Bjoern

2009-01-01

It is still an unanswered question whether a relatively low dose of radiation to a large volume or a higher dose to a small volume produces the higher cancer incidence. This is of interest in view of modalities like IMRT or rotation therapy where high conformity to the target volume is achieved at the cost of a large volume of normal tissue exposed to radiation. Knowledge of the shape of the dose response for radiation-induced cancer is essential to answer the question of what risk of second cancer incidence is implied by which treatment modality. This study therefore models the dose response for radiation-induced second cancer after radiation therapy of which the exact mechanisms are still unknown. A second cancer risk estimation tool for treatment planning is presented which has the potential to be used for comparison of different treatment modalities, and risk is estimated on a voxel basis for different organs in two case studies. The presented phenomenological model summarises the impact of microscopic biological processes into effective parameters of mutation and cell sterilisation. In contrast to other models, the effective radiosensitivities of mutated and non-mutated cells are allowed to differ. Based on the number of mutated cells present after irradiation, the model is then linked to macroscopic incidence by summarising model parameters and modifying factors into natural cancer incidence and the dose response in the lower-dose region. It was found that all principal dose-response functions discussed in the literature can be derived from the model. However, from the investigation and due to scarcity of adequate data, rather vague statements about likelihood of dose-response functions can be made than a definite decision for one response. Based on the predicted model parameters, the linear response can probably be rejected using the dynamics described, but both a flattening response and a decrease appear likely, depending strongly on the effective cell

Medical applications of synchrotron radiation. Ch. 10

International Nuclear Information System (INIS)

Giacomini, J.C.; Gordon, H.J.

1991-01-01

Synchrotron radiation has a number of properties which make it uniquely suited for medical diagnostic imaging. The radiation is intense and can be readily monochromatized. With these highly intense, mono-chromatized X-ray beams, iodine K-edge di-chromatography can yield images which greatly enhance the visualization of iodine containing structures. As this technology continues to improve, the possibility of performing diagnostic cardiac, neuroradiological, and other vascular examinations with minimally invasive peripheral venous injections of iodinated contrast agent becomes increasingly practical. (author). 10 refs.; 6 figs

Natural background radiation and oncologic disease incidence

International Nuclear Information System (INIS)

Burenin, P.I.

1982-01-01

Cause and effect relationships between oncologic disease incidence in human population and environmental factors are examined using investigation materials of Soviet and foreign authors. The data concerning US white population are adduced. The role and contribution of natural background radiation oncologic disease prevalence have been determined with the help of system information analysis. The probable damage of oncologic disease is shown to decrease as the background radiation level diminishes. The linear nature of dose-response relationspip has been established. The necessity to include the life history of the studied population along with environmental factors in epidemiological study under conditions of multiplicity of cancerogenesis causes is emphasized

Medical treatment of radiation damages and medical emergency planning in case of nuclear power plant incidents and accidents

International Nuclear Information System (INIS)

Ohlenschlaeger, L.

1981-03-01

Medical measures in case of radiation damages are discussed on the basis of five potential categories of radiation incidents and accidents, respectively, viz. contaminations, incorporations, external local and general radiation over-exposures, contaminated wounds, and combinations of radiation damages and conventional injuries. Considerations are made for diagnostic and therapeutic initial measures especially in case of minor and moderate radiation accidents. The medical emergency planning is reviewed by means of definations used in the practical handling of incidents or accidents. The parameters are: extent of the incident or accident, number of persons involved, severity of radiation damage. Based on guiding symptoms the criteria for the classification into minor, moderate or severe radiation accidents are discussed. Reference is made to the Medical Radiation Protection Centers existing in the Federal Republic of Germany and the possibility of getting advices in case of radiation incidents and accidents. (orig.) [de

Reversal of diabetic peripheral neuropathy and new wound incidence: the role of MIRE.

Science.gov (United States)

Powell, Mark W; Carnegie, Dale E; Burke, Thomas J

2004-01-01

To determine if improved foot sensitivity to the Semmes-Weinstein 10-g (5.07) monofilament, originally impaired because of diabetic peripheral neuropathy, might be associated with a reduced incidence of new diabetic foot wounds. Retrospective cohort study using a health status questionnaire. Sixty-eight individuals over age 64 with diabetes, diabetic peripheral neuropathy, and loss of protective sensation who had clinically demonstrable increases in foot sensation to the Semmes-Weinstein monofilament after treatment with monochromatic near infrared photo energy. After reversal of diabetic peripheral neuropathy following treatment with monochromatic near infrared photo energy, only 1 of 68 patients developed a new diabetic foot wound, for an incidence of 1.5%. Comparatively, the incidence previously reported in the Medicare-aged population with diabetes was 7.3%. Improved foot sensitivity to the Semmes-Weinstein monofilament in patients previously suffering from loss of protective sensation due to diabetic neuropathy appears to be associated with a lower incidence of new diabetic foot ulcers when compared with the expected incidence in the Medicare-aged population with diabetes. Therapeutic interventions that effectively improve foot sensitivity that has been previously diminished due to diabetic peripheral neuropathy may substantially reduce the incidence of new foot wounds in the Medicare-aged population with diabetes.

Radiation incident in oil well logging

International Nuclear Information System (INIS)

Lozada, J.A.

1998-01-01

On June 4th 1997 equipment failure and violation of approved procedures by a crew of workers initiated a series of events that resulted in the unnecessary exposure to neutron and gamma radiation, from a 666 GBq Am 241 Be source, of forty two workers from a well logging company in Venezuela. Due to the presence of dry mud or drilling fluids inside the logging tool, the nosepiece was screwed off the rest of the source holder; this piece was mistaken for the entire source holder thus leaving the source inside the tool. The tool was labelled for maintenance and electronic laboratory personal worked near the source for seven hours before they identify its presence. As soon as the incident was detected a contingency plan was implemented and the source could be retrieved from the tool and placed in its shipping container. The TLD badges indicate doses well below the annual limit of 20 mSv, and none of the workers involved in the incident seem to show serious health consequences from it. After the incident, in order to avoid the occurrence of similar situations, a better source and tool maintenance program was implemented, all the workers were re-trained, and area monitors were installed in all operations bases. (author)

SU-E-T-524: Web-Based Radiation Oncology Incident Reporting and Learning System (ROIRLS)

Energy Technology Data Exchange (ETDEWEB)

Kapoor, R; Palta, J; Hagan, M [Virginia Commonwealth University, Richmond, VA (United States); National Radiation Oncology Program (10P4H), Richmond, VA (United States); Grover, S; Malik, G [TSG Innovations Inc., Richmond, VA (United States)

2014-06-01

Purpose: Describe a Web-based Radiation Oncology Incident Reporting and Learning system that has the potential to improve quality of care for radiation therapy patients. This system is an important facet of continuing effort by our community to maintain and improve safety of radiotherapy.Material and Methods: The VA National Radiation Oncology Program office has embarked on a program to electronically collect adverse events and near miss data of radiation treatment of over 25,000 veterans treated with radiotherapy annually. Software used for this program is deployed on the VAs intranet as a Website. All data entry forms (adverse event or near miss reports, work product reports) utilize standard causal, RT process step taxonomies and data dictionaries defined in AAPM and ASTRO reports on error reporting (AAPM Work Group Report on Prevention of Errors and ASTROs safety is no accident report). All reported incidents are investigated by the radiation oncology domain experts. This system encompasses the entire feedback loop of reporting an incident, analyzing it for salient details, and developing interventions to prevent it from happening again. The operational workflow is similar to that of the Aviation Safety Reporting System. This system is also synergistic with ROSIS and SAFRON. Results: The ROIRLS facilitates the collection of data that help in tracking adverse events and near misses and develop new interventions to prevent such incidents. The ROIRLS electronic infrastructure is fully integrated with each registered facility profile data thus minimizing key strokes and multiple entries by the event reporters. Conclusions: OIRLS is expected to improve the quality and safety of a broad spectrum of radiation therapy patients treated in the VA and fulfills our goal of Effecting Quality While Treating Safely The Radiation Oncology Incident Reporting and Learning System software used for this program has been developed, conceptualized and maintained by TSG Innovations

SU-E-T-524: Web-Based Radiation Oncology Incident Reporting and Learning System (ROIRLS)

International Nuclear Information System (INIS)

Kapoor, R; Palta, J; Hagan, M; Grover, S; Malik, G

2014-01-01

Purpose: Describe a Web-based Radiation Oncology Incident Reporting and Learning system that has the potential to improve quality of care for radiation therapy patients. This system is an important facet of continuing effort by our community to maintain and improve safety of radiotherapy.Material and Methods: The VA National Radiation Oncology Program office has embarked on a program to electronically collect adverse events and near miss data of radiation treatment of over 25,000 veterans treated with radiotherapy annually. Software used for this program is deployed on the VAs intranet as a Website. All data entry forms (adverse event or near miss reports, work product reports) utilize standard causal, RT process step taxonomies and data dictionaries defined in AAPM and ASTRO reports on error reporting (AAPM Work Group Report on Prevention of Errors and ASTROs safety is no accident report). All reported incidents are investigated by the radiation oncology domain experts. This system encompasses the entire feedback loop of reporting an incident, analyzing it for salient details, and developing interventions to prevent it from happening again. The operational workflow is similar to that of the Aviation Safety Reporting System. This system is also synergistic with ROSIS and SAFRON. Results: The ROIRLS facilitates the collection of data that help in tracking adverse events and near misses and develop new interventions to prevent such incidents. The ROIRLS electronic infrastructure is fully integrated with each registered facility profile data thus minimizing key strokes and multiple entries by the event reporters. Conclusions: OIRLS is expected to improve the quality and safety of a broad spectrum of radiation therapy patients treated in the VA and fulfills our goal of Effecting Quality While Treating Safely The Radiation Oncology Incident Reporting and Learning System software used for this program has been developed, conceptualized and maintained by TSG Innovations

Three-dimensional polarization states of monochromatic light fields.

Science.gov (United States)

Azzam, R M A

2011-11-01

The 3×1 generalized Jones vectors (GJVs) [E(x) E(y) E(z)](t) (t indicates the transpose) that describe the linear, circular, and elliptical polarization states of an arbitrary three-dimensional (3-D) monochromatic light field are determined in terms of the geometrical parameters of the 3-D vibration of the time-harmonic electric field. In three dimensions, there are as many distinct linear polarization states as there are points on the surface of a hemisphere, and the number of distinct 3-D circular polarization states equals that of all two-dimensional (2-D) polarization states on the Poincaré sphere, of which only two are circular states. The subset of 3-D polarization states that results from the superposition of three mutually orthogonal x, y, and z field components of equal amplitude is considered as a function of their relative phases. Interesting contours of equal ellipticity and equal inclination of the normal to the polarization ellipse with respect to the x axis are obtained in 2-D phase space. Finally, the 3×3 generalized Jones calculus, in which elastic scattering (e.g., by a nano-object in the near field) is characterized by the 3-D linear transformation E(s)=T E(i), is briefly introduced. In such a matrix transformation, E(i) and E(s) are the 3×1 GJVs of the incident and scattered waves and T is the 3×3 generalized Jones matrix of the scatterer at a given frequency and for given directions of incidence and scattering.

Radiation biology using synchrotron radiation. In relation to radiation chemistry as an initial process

International Nuclear Information System (INIS)

Kobayashi, Katsumi

1995-01-01

Radiation biology using synchrotron radiation have been investigated, focusing on the mechanism of the formation of molecular damage. This paper introduces recent outcome of these studies. First, the process from imparted energy to the formation of molecular damage is outlined. The previous studies can be largely categorized as dealing with (1) biological effects of inner-shell ionization on elements composing the living body and (2) X-ray energy dependence of biological effects. Bromine and phosphorus are used as elements for the study of inner-cell ionization. In the study on lethal effects of monochromatic soft X-rays on the BrdUMP-incorporated yeast cells, Auger enhancement was found to occur. The first report on the effects of K-shell absorption of cellular phosphorus atoms has revealed that biological effects on cellular lethality and genetic changes was enhanced by 40%. Plasmid DNA and oligonucleotide have been used to study biological effects of vacuum ultraviolet rays to monochromatic soft X-ray, which makes it possible to study strand breaks. Because experimental production of energy required for the formation of double strand breaks has become possible, synchrotron radiation plays a very important role in radiation biological studies. Finally, future issues are presented. (N.K.)

The Equivalent Uniform Dose as a severity metric for radiation treatment incidents

International Nuclear Information System (INIS)

Dunscombe, Peter B.; Iftody, Sandra; Ploquin, Nicolas; Ekaette, Edidiong U.; Lee, Robert C.

2007-01-01

In allocating resources within a risk management program, ideally we would like to know both the probabilities and consequences of potential incidents. We simulate, on a treatment planning computer, several commonly reported incidents in radiation treatment and explore their consequences for the EUDs of targets and organs at risk

Monochromatic minibeam radiotherapy: theoretical and experimental dosimetry for preclinical treatment plans

Energy Technology Data Exchange (ETDEWEB)

Deman, P; Vautrin, M; Stupar, V; Barbier, E L; Elleaume, H; Esteve, F; Adam, J F, E-mail: adam@esrf.fr [INSERM, U836, BP 170, Grenoble Cedex 9, F-38042 (France)

2011-07-21

Monochromatic x-ray minibeam radiotherapy is a new radiosurgery approach based on arrays of submillimetric interlaced planar x-ray beams. The aim of this study was to characterize the dose distributions obtained with this new modality when being used for preclinical trials. Monte Carlo simulations were performed in water phantoms. Percentage depth-dose curves and dose profiles were computed for single incidences and interleaved incidences of 80 keV planar x-ray minibeam (0.6 x 5 mm) arrays. Peak to valley dose ratios were also computed at various depths for an increasing number of minibeams. 3D experimental polymer gel (nPAG) dosimetry measurements were performed using MRI devices designed for small animal imaging. These very high spatial resolution (50 {mu}m) dose maps were compared to the simulations. Preclinical minibeams dose distributions were fully characterized. Experimental dosimetry correlated well with Monte Carlo calculations (Student t-tests: p > 0.1). F98 tumor-bearing rats were also irradiated with interleaved minibeams (80 keV, prescribed dose: 25 Gy). This associated preclinical trial serves as a proof of principle of the technique. The mean survival time of irradiated glioma-bearing rats increased significantly, when compared to the untreated animals (59.6 {+-} 2.8 days versus 28.25 {+-} 0.75 days, p < 0.001).

Medical and policy considerations for nuclear and radiation accidents, incidents and terrorism.

Science.gov (United States)

Gale, Robert Peter

2017-11-01

The purpose of this review is to address the increasing medical and public concern regarding the health consequences of radiation exposure, a concern shaped not only by fear of another Chernobyl or Fukushima nuclear power facility accident but also by the intentional use of a nuclear weapon, a radiological dispersion device, a radiological exposure device, or an improved nuclear device by rogue states such as North Korea and terrorist organizations such as Al Qaeda and ISIS. The United States has the medical capacity to respond to a limited nuclear or radiation accident or incident but an effective medical response to a catastrophic nuclear event is impossible. Dealing effectively with nuclear and radiation accidents or incidents requires diverse strategies, including policy decisions, public education, and medical preparedness. I review medical consequences of exposures to ionizing radiations, likely concomitant injuries and potential medical intervention. These data should help haematologists and other healthcare professionals understand the principles of medical consequences of nuclear terrorism. However, the best strategy is prevention.

Learning from radiation incidents: the new OTHEA website

International Nuclear Information System (INIS)

Shaw, P V; Ely, S Y; Croueail, P; Bataille, C

2010-01-01

OTHEA is the name of a new website (www.othea.net), created by the Health Protection Agency (UK) and the Centre d'etude sur l'evaluation de la protection dans le domaine nucleaire (CEPN, France), and supported by several other stakeholders including national societies and associations. The website is bi-lingual (French and English) and the purpose is to share the lessons learnt from radiological incidents that have occurred in the industrial, medical, research and teaching, and other non-nuclear sectors. OTHEA contains a collection of incident reports, categorised according to the sector and the type of application, and a search facility. The reports can be freely downloaded and printed, for example for use in radiation protection training activities. To encourage dissemination, the incident reports have been made anonymous, i.e. any information that could identify a particular individual, organisation or site has been removed. Each report contains a brief summary of the incident, the radiological consequences, and the lessons learnt. The aim is not to capture every single incident, but to provide a range of reports selected according to the value of the lessons learnt. For OTHEA to be a long-term success, it needs to be sustained with new reports. Therefore users are encouraged to submit incident reports that can be considered for inclusion in OTHEA. This note summarises the background to OTHEA, and provides a description of the operating features and content at its launch in summer 2010. (note)

The use of Co2+ for crystallization and structure determination, using a conventional monochromatic X-ray source, of flax rust avirulence protein

International Nuclear Information System (INIS)

Gunčar, Gregor; Wang, Ching-I A.; Forwood, Jade K.; Teh, Trazel; Catanzariti, Ann-Maree; Ellis, Jeffrey G.; Dodds, Peter N.; Kobe, Boštjan

2007-01-01

It is demonstrated that anomalous diffraction based on the signal from a cobalt ion measured on a conventional monochromatic X-ray source can be used to determine the structure of a protein with a novel fold (M. lini avirulence protein AvrL567-A). The approach could be applicable to many metal-binding proteins, particularly when synchrotron radiation is not readily available. Metal-binding sites are ubiquitous in proteins and can be readily utilized for phasing. It is shown that a protein crystal structure can be solved using single-wavelength anomalous diffraction based on the anomalous signal of a cobalt ion measured on a conventional monochromatic X-ray source. The unique absorption edge of cobalt (1.61 Å) is compatible with the Cu Kα wavelength (1.54 Å) commonly available in macromolecular crystallography laboratories. This approach was applied to the determination of the structure of Melampsora lini avirulence protein AvrL567-A, a protein with a novel fold from the fungal pathogen flax rust that induces plant disease resistance in flax plants. This approach using cobalt ions may be applicable to all cobalt-binding proteins and may be advantageous when synchrotron radiation is not readily available

Multiple scattering of polarized light: comparison of Maxwell theory and radiative transfer theory.

Science.gov (United States)

Voit, Florian; Hohmann, Ansgar; Schäfer, Jan; Kienle, Alwin

2012-04-01

For many research areas in biomedical optics, information about scattering of polarized light in turbid media is of increasing importance. Scattering simulations within this field are mainly performed on the basis of radiative transfer theory. In this study a polarization sensitive Monte Carlo solution of radiative transfer theory is compared to exact Maxwell solutions for all elements of the scattering Müller matrix. Different scatterer volume concentrations are modeled as a multitude of monodisperse nonabsorbing spheres randomly positioned in a cubic simulation volume which is irradiated with monochromatic incident light. For all Müller matrix elements effects due to dependent scattering and multiple scattering are analysed. The results are in overall good agreement between the two methods with deviations related to dependent scattering being prominent for high volume concentrations and high scattering angles.

Synthesizing monochromatic 3-D images by multiple-exposure rainbow holography with vertical area-partition approach

Institute of Scientific and Technical Information of China (English)

翟宏琛; 王明伟; 刘福民; 母国光

2002-01-01

We report for the first time the theoretical analysis and experimental results of a white-light reconstructed monochromatic 3-D image synthesizing tomograms by multiple rainbow holo-graphy with vertical-area partition (VAP) approach. The theoretical and experimental results show that 3-D monochromatic image can be synthesized by recording the master hologram by VAP ap-proach without any distortions either in gray scale or in geometrical position. A 3-D monochromatic image synthesized from a series of medical tomograms is presented in this paper for the first time.

Brain tumors and synchrotron radiation: Methodological developments in quantitative brain perfusion imaging and radiation therapy

International Nuclear Information System (INIS)

Adam, Jean-Francois

2005-01-01

High-grade gliomas are the most frequent type of primary brain tumors in adults. Unfortunately, the management of glioblastomas is still mainly palliative and remains a difficult challenge, despite advances in brain tumor molecular biology and in some emerging therapies. Synchrotron radiation opens fields for medical imaging and radiation therapy by using monochromatic intense x-ray beams. It is now well known that angiogenesis plays a critical role in the tumor growth process and that brain perfusion is representative of the tumor mitotic activity. Synchrotron radiation quantitative computed tomography (SRCT) is one of the most accurate techniques for measuring in vivo contrast agent concentration and thus computing precise and accurate absolute values of the brain perfusion key parameters. The methodological developments of SRCT absolute brain perfusion measurements as well as their preclinical validation are detailed in this thesis. In particular, absolute cerebral volume and blood brain barrier permeability high-resolution (pixel size 2 ) parametric maps were reported. In conventional radiotherapy, the treatment of these tumors remains a delicate challenge, because the damages to the surrounding normal brain tissue limit the amount of radiation that can be delivered. One strategy to overcome this limitation is to infuse an iodinated contrast agent to the patient during the irradiation. The contrast agent accumulates in the tumor, through the broken blood brain barrier, and the irradiation is performed with kilovoltage x rays, in tomography mode, the tumor being located at the center of rotation and the beam size adjusted to the tumor dimensions. The dose enhancement results from the photoelectric effect on the heavy element and from the irradiation geometry. Synchrotron beams, providing high intensity, tunable monochromatic x rays, are ideal for this treatment. The beam properties allow the selection of monochromatic irradiation, at the optimal energy, for a

Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

International Nuclear Information System (INIS)

Gerlach, M.; Krumrey, M.; Cibik, L.; Mueller, P.; Ulm, G.

2009-01-01

Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

Science.gov (United States)

Gerlach, M.; Krumrey, M.; Cibik, L.; Müller, P.; Ulm, G.

2009-09-01

Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

Energy Technology Data Exchange (ETDEWEB)

Gerlach, M. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Krumrey, M. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)], E-mail: Michael.Krumrey@ptb.de; Cibik, L.; Mueller, P.; Ulm, G. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

2009-09-11

Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

Periprosthetic Artifact Reduction Using Virtual Monochromatic Imaging Derived From Gemstone Dual-Energy Computed Tomography and Dedicated Software.

Science.gov (United States)

Reynoso, Exequiel; Capunay, Carlos; Rasumoff, Alejandro; Vallejos, Javier; Carpio, Jimena; Lago, Karen; Carrascosa, Patricia

2016-01-01

The aim of this study was to explore the usefulness of combined virtual monochromatic imaging and metal artifact reduction software (MARS) for the evaluation of musculoskeletal periprosthetic tissue. Measurements were performed in periprosthetic and remote regions in 80 patients using a high-definition scanner. Polychromatic images with and without MARS and virtual monochromatic images were obtained. Periprosthetic polychromatic imaging (PI) showed significant differences compared with remote areas among the 3 tissues explored (P remote tissues using monochromatic imaging with MARS (P = 0.053 bone, P = 0.32 soft tissue, and P = 0.13 fat). However, such differences were significant using PI with MARS among bone (P = 0.005) and fat (P = 0.02) tissues. All periprosthetic areas were noninterpretable using PI, compared with 11 (9%) using monochromatic imaging. The combined use of virtual monochromatic imaging and MARS reduced periprosthetic artifacts, achieving attenuation levels comparable to implant-free tissue.

Molecular dynamics study of radiation damage and microstructure evolution of zigzag single-walled carbon nanotubes under carbon ion incidence

Science.gov (United States)

Li, Huan; Tang, Xiaobin; Chen, Feida; Huang, Hai; Liu, Jian; Chen, Da

2016-07-01

The radiation damage and microstructure evolution of different zigzag single-walled carbon nanotubes (SWCNTs) were investigated under incident carbon ion by molecular dynamics (MD) simulations. The radiation damage of SWCNTs under incident carbon ion with energy ranging from 25 eV to 1 keV at 300 K showed many differences at different incident sites, and the defect production increased to the maximum value with the increase in incident ion energy, and slightly decreased but stayed fairly stable within the majority of the energy range. The maximum damage of SWCNTs appeared when the incident ion energy reached 200 eV and the level of damage was directly proportional to incident ion fluence. The radiation damage was also studied at 100 K and 700 K and the defect production decreased distinctly with rising temperature because radiation-induced defects would anneal and recombine by saturating dangling bonds and reconstructing carbon network at the higher temperature. Furthermore, the stability of a large-diameter tube surpassed that of a thin one under the same radiation environments.

Relationship of cancer incidence to terrestrial radiation and population density in Connecticut, 1935-1974

International Nuclear Information System (INIS)

Walter, S.D.; Meigs, J.W.; Heston, J.F.

1986-01-01

The relationship of cancer incidence to terrestrial radiation and population density was investigated. Cancer incidence was obtained using 40 years of age-standardized data from the Connecticut Tumor Registry, and environmental radiation was estimated using data from an airborne gamma radiation survey of the entire state. These variables were examined ecologically, using the 169 towns of the state as the analytic units in a weighted regression analysis. The study design involves a large population base in a state having relatively high terrestrial radiation exposure levels overall and reasonable variation in exposure between towns. For all cancer combined, only one of the eight sex-specific analyses by decade yielded a significant radiation regression coefficient, and this was negative. In the sex- and site-specific analyses, almost all the coefficients for radiation were not significantly different from zero. In contrast, significant positive relationships of cancer incidence with population density were found for all cancer, for cancer of the lung for both sexes, for stomach, colonic, and prostatic cancer for males, and for lymphomas, thyroid, breast, and ovarian cancer for females. Both the radiation and population density relationships were adjusted for socioeconomic status. Socioeconomic status was significantly negatively associated with stomach and lung cancer in males and with cervical cancer in females; it was also positively associated with lymphomas and breast cancer in females. A power calculation revealed that, despite the relatively large size of this study, there was only a small probability of detecting a radiation effect of the strength anticipated from previous estimates

Radiation incidents with a cobalt-60 teletherapy unit

Energy Technology Data Exchange (ETDEWEB)

Lane, R G; Tolbert, D D; Pailwal, B R; Radtke, R R [Wisconsin Univ., Madison (USA). Dept. of Radiology

1976-08-01

Three radiation incidents associated with source drive failures on one particular /sup 60/Co teletherapy unit, which took place during a single year's operation, are discussed. In each case the extra treatment time of the patient, the exposure to the technician, the cause of the breakdown and the subsequent action taken are detailed. Recommendations for users of /sup 60/Co teletherapy units to minimise the results of the malfunctioning of such a system are given.

Radiation incidents with a cobalt-60 teletherapy unit

International Nuclear Information System (INIS)

Lane, R.G.; Tolbert, D.D.; Pailwal, B.R.; Radtke, R.R.

1976-01-01

Three radiation incidents associated with source drive failures on one particular 60 Co teletherapy unit, which took place during a single year's operation, are discussed. In each case the extra treatment time of the patient, the exposure to the technician, the cause of the breakdown and the subsequent action taken are detailed. Recommendations for users of 60 Co teletherapy units to minimise the results of the malfunctioning of such a system are given. (U.K.)

Study of the initial processes of radiation effects using synchrotron radiation

International Nuclear Information System (INIS)

Kobayashi, Katsumi

1990-01-01

Necessity for the research of production mechanisms of molecular damages in biological system and usefulness of monochromatic soft X-ray in these studies are described. Synchrotron radiation are introduced as a strong light source with continuous spectrum. Practically, it is the only light source in soft X-ray and vacuum UV region. Development of irradiation apparatus for radiation biology and recent results using various biological systems are reviewed. (author)

Female all cancer incidence in medical radiation workers in Latvia 1982-2002

International Nuclear Information System (INIS)

Matisane, L.; Carpenter, L.; Venables, K.

2005-01-01

Medical radiation workers belong to one of the oldest occupational groups exposed to external radiation. Since the various radiological protection recommendations have been introduced, now ths process has resulted in low-dose exposure, regular monitoring of exposure and establishment of national dose registration bodies. In order to provide additional information to studies on cancer incidence among medical radiation workers (specially female workers) and in order to assess all cancer incidence in female medical radiation workers in Latvia, a retrospective cohort study based on the National Dose Register was set up in Latvia. The study cohort consisted of all workers employed in health care, occupationally exposed to ionising radiation for more than one year in any of the public health care establishments in Latvia, except military ones, between 1 January 1972 and 1 January 2002 and who were registered in the National Dose Register of Latvia. The cohort consisted of 1416 female medical radiation workers either in hospitals or outpatient departments, or both. The cohort included diagnostic and therapeutic radiologists with predominantly medical qualification, it also included radiotechnologits, nurses, junior nurses, but it did not include academic, physicists and dentists. In all cases the calculated SIR was over than expected or close to expected. Several major differences in study design makes ir difficult to compare the results of this study with the results of the studies carried out in other countries

Radiation-Induced Breast Cancer Incidence and Mortality From Digital Mammography Screening: A Modeling Study.

Science.gov (United States)

Miglioretti, Diana L; Lange, Jane; van den Broek, Jeroen J; Lee, Christoph I; van Ravesteyn, Nicolien T; Ritley, Dominique; Kerlikowske, Karla; Fenton, Joshua J; Melnikow, Joy; de Koning, Harry J; Hubbard, Rebecca A

2016-02-16

Estimates of risk for radiation-induced breast cancer from mammography screening have not considered variation in dose exposure or diagnostic work-up after abnormal screening results. To estimate distributions of radiation-induced breast cancer incidence and mortality from digital mammography screening while considering exposure from screening and diagnostic mammography and dose variation among women. 2 simulation-modeling approaches. U.S. population. Women aged 40 to 74 years. Annual or biennial digital mammography screening from age 40, 45, or 50 years until age 74 years. Lifetime breast cancer deaths averted (benefits) and radiation-induced breast cancer incidence and mortality (harms) per 100,000 women screened. Annual screening of 100,000 women aged 40 to 74 years was projected to induce 125 breast cancer cases (95% CI, 88 to 178) leading to 16 deaths (CI, 11 to 23), relative to 968 breast cancer deaths averted by early detection from screening. Women exposed at the 95th percentile were projected to develop 246 cases of radiation-induced breast cancer leading to 32 deaths per 100,000 women. Women with large breasts requiring extra views for complete examination (8% of population) were projected to have greater radiation-induced breast cancer risk (266 cancer cases and 35 deaths per 100,000 women) than other women (113 cancer cases and 15 deaths per 100,000 women). Biennial screening starting at age 50 years reduced risk for radiation-induced cancer 5-fold. Life-years lost from radiation-induced breast cancer could not be estimated. Radiation-induced breast cancer incidence and mortality from digital mammography screening are affected by dose variability from screening, resultant diagnostic work-up, initiation age, and screening frequency. Women with large breasts may have a greater risk for radiation-induced breast cancer. Agency for Healthcare Research and Quality, U.S. Preventive Services Task Force, National Cancer Institute.

The optimal monochromatic spectral computed tomographic imaging plus adaptive statistical iterative reconstruction algorithm can improve the superior mesenteric vessel image quality

Energy Technology Data Exchange (ETDEWEB)

Yin, Xiao-Ping; Zuo, Zi-Wei; Xu, Ying-Jin; Wang, Jia-Ning [CT/MRI room, Affiliated Hospital of Hebei University, Baoding, Hebei, 071000 (China); Liu, Huai-Jun, E-mail: hebeiliu@outlook.com [Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050000 (China); Liang, Guang-Lu [CT/MRI room, Affiliated Hospital of Hebei University, Baoding, Hebei, 071000 (China); Gao, Bu-Lang, E-mail: browngao@163.com [Department of Medical Research, Shijiazhuang First Hospital, Shijiazhuang, Hebei, 050011 (China)

2017-04-15

Objective: To investigate the effect of the optimal monochromatic spectral computed tomography (CT) plus adaptive statistical iterative reconstruction on the improvement of the image quality of the superior mesenteric artery and vein. Materials and methods: The gemstone spectral CT angiographic data of 25 patients were reconstructed in the following three groups: 70 KeV, the optimal monochromatic imaging, and the optimal monochromatic plus 40%iterative reconstruction mode. The CT value, image noises (IN), background CT value and noises, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and image scores of the vessels and surrounding tissues were analyzed. Results: In the 70 KeV, the optimal monochromatic and the optimal monochromatic images plus 40% iterative reconstruction group, the mean scores of image quality were 3.86, 4.24 and 4.25 for the superior mesenteric artery and 3.46, 3.78 and 3.81 for the superior mesenteric vein, respectively. The image quality scores for the optimal monochromatic and the optimal monochromatic plus 40% iterative reconstruction groups were significantly greater than for the 70 KeV group (P < 0.05). The vascular CT value, image noise, background noise, CNR and SNR were significantly (P < 0.001) greater in the optimal monochromatic and the optimal monochromatic images plus 40% iterative reconstruction group than in the 70 KeV group. The optimal monochromatic plus 40% iterative reconstruction group had significantly (P < 0.05) lower image and background noise but higher CNR and SNR than the other two groups. Conclusion: The optimal monochromatic imaging combined with 40% iterative reconstruction using low-contrast agent dosage and low injection rate can significantly improve the image quality of the superior mesenteric artery and vein.

Are passive smoking, air pollution and obesity a greater mortality risk than major radiation incidents?

Directory of Open Access Journals (Sweden)

Smith Jim T

2007-04-01

Full Text Available Abstract Background Following a nuclear incident, the communication and perception of radiation risk becomes a (perhaps the major public health issue. In response to such incidents it is therefore crucial to communicate radiation health risks in the context of other more common environmental and lifestyle risk factors. This study compares the risk of mortality from past radiation exposures (to people who survived the Hiroshima and Nagasaki atomic bombs and those exposed after the Chernobyl accident with risks arising from air pollution, obesity and passive and active smoking. Methods A comparative assessment of mortality risks from ionising radiation was carried out by estimating radiation risks for realistic exposure scenarios and assessing those risks in comparison with risks from air pollution, obesity and passive and active smoking. Results The mortality risk to populations exposed to radiation from the Chernobyl accident may be no higher than that for other more common risk factors such as air pollution or passive smoking. Radiation exposures experienced by the most exposed group of survivors of Hiroshima and Nagasaki led to an average loss of life expectancy significantly lower than that caused by severe obesity or active smoking. Conclusion Population-averaged risks from exposures following major radiation incidents are clearly significant, but may be no greater than those from other much more common environmental and lifestyle factors. This comparative analysis, whilst highlighting inevitable uncertainties in risk quantification and comparison, helps place the potential consequences of radiation exposures in the context of other public health risks.

Application Research of Quasi-monochromatic X-ray Machine Replacing 241Am Radioactive Source in Thickness Measurement

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LIN Hui1;XIAO Xue-fu2;HOU Yue-xin3;ZHAO Jing1;JIAN Li-min1

2014-02-01

Full Text Available In the research of BS-03 thickness detector, a self-designed quasi-monochromatic (50-60 keV X-ray machine was studied as a substitution to Am-241 low energy photon source（1.11×109 Bq）The range of output current, the attenuation of X rays through the steel plate, the aluminum plate, and the organic glass plate and stability of quasi-monochromatic X-ray machine was tested. The result showed that quasi-monochromatic X-ray machine could be an applicable replacement of Am-241 radioactive source.

Has the incidence of radiation-induced bowel damage following treatment of uterine carcinoma changed in the last 20 years

International Nuclear Information System (INIS)

Allen-Mersh, T.C.; Wilson, E.J.; Hope-Stone, H.F.; Mann, C.V.

1986-01-01

Radiation-induced bowel damage occurred in 4.3% of patients treated primarily by irradiation for uterine carcinoma during the period 1962-1982. There has been a progressive rise in the incidence of radiation damage and radiation-induced rectovaginal fistula during this 20-year period. Radiation from intracavitary sources was a contributory factor in 92% of injured cases. The rising incidence of bowel damage in our patients may be due to an increase in the number of patients receiving a high rectal dose from the intracavitary source. There was a significantly (P<0.01) higher incidence of radiation injury in cases of cervical carcinoma compared to endometrical carcinoma. This was because cervical carcinoma tended to present at a more advanced stage than endometrial carcinoma and was more frequently treated with combined external and intracavitary irradiation. There was no significant increase in the incidence of complications among patients undergoing hysterectomy. (author)

An analysis of the incidence and related factors for radiation dermatitis in breast cancer patients who receive radiation therapy

International Nuclear Information System (INIS)

Lee, Sun Young; Kwon, Hyoung Cheol; Kim, Jung Soo; Lee, Heui Kwan

2010-01-01

We analyzed the incidence and related factors of radiation dermatitis; at first, to recognize whether a decrease in radiation dermatitis is possible or not in breast cancer patients who received radiation therapy. Of 338 patients, 284 with invasive breast cancer who received breast conservation surgery with radiotherapy at Chonbuk National University Hospital from January 2007 to June 2009 were evaluated. Patients who also underwent bolus, previous contralateral breast irradiation and irradiation on both breasts were excluded. For patients who appeared to have greater than moderate radiation dermatitis, the incidence and relating factors for radiation dermatitis were analyzed retrospectively. A total of 207 and 77 patients appeared to have RTOG grade 0/1 or above RTOG grade 2 radiation dermatitis, respectively. The factors found to be statistically significant for the 77 patients who appeared to have greater than moderate radiation dermatitis include the presence of lymphocele due to the stasis of lymph and lymph edema which affect the healing disturbance of radiation dermatitis (p=0.003, p=0.001). Moreover, an allergic reaction to plaster due to the immune cells of skin and the activation of cytokine and concomitant hormonal therapy were also statistically significant factors (p=0.001, p=0.025). Most of the breast cancer patients who received radiation therapy appeared to have a greater than mild case of radiation dermatitis. Lymphocele, lymphedema, an allergy to plaster and concomitant hormonal therapy which affect radiation dermatitis were found to be significant factors. Consequently, we should eliminate lymphocele prior to radiation treatment for patients who appear to have an allergic reaction to plaster. We should also instruct patients of methods to maintain skin moisture if they appear to have a greater than moderate case of radiation dermatitis.

Estimating photosynthetic radiation use efficiency using incident light and photosynthesis of individual leaves.

Science.gov (United States)

Rosati, A; Dejong, T M

2003-06-01

It has been theorized that photosynthetic radiation use efficiency (PhRUE) over the course of a day is constant for leaves throughout a canopy if leaf nitrogen content and photosynthetic properties are adapted to local light so that canopy photosynthesis over a day is optimized. To test this hypothesis, 'daily' photosynthesis of individual leaves of Solanum melongena plants was calculated from instantaneous rates of photosynthesis integrated over the daylight hours. Instantaneous photosynthesis was estimated from the photosynthetic responses to photosynthetically active radiation (PAR) and from the incident PAR measured on individual leaves during clear and overcast days. Plants were grown with either abundant or scarce N fertilization. Both net and gross daily photosynthesis of leaves were linearly related to daily incident PAR exposure of individual leaves, which implies constant PhRUE over a day throughout the canopy. The slope of these relationships (i.e. PhRUE) increased with N fertilization. When the relationship was calculated for hourly instead of daily periods, the regressions were curvilinear, implying that PhRUE changed with time of the day and incident radiation. Thus, linearity (i.e. constant PhRUE) was achieved only when data were integrated over the entire day. Using average PAR in place of instantaneous incident PAR increased the slope of the relationship between daily photosynthesis and incident PAR of individual leaves, and the regression became curvilinear. The slope of the relationship between daily gross photosynthesis and incident PAR of individual leaves increased for an overcast compared with a clear day, but the slope remained constant for net photosynthesis. This suggests that net PhRUE of all leaves (and thus of the whole canopy) may be constant when integrated over a day, not only when the incident PAR changes with depth in the canopy, but also when it varies on the same leaf owing to changes in daily incident PAR above the canopy. The

Monochromatic computed tomography of the human brain using synchrotron x rays: Technical feasibility

International Nuclear Information System (INIS)

Nachaliel, E.; Dilmanian, F.A.; Garrett, R.F.; Thomlinson, W.C.; Chapman, L.D.; Gmuer, N.F.; Lazarz, N.M.; Moulin, H.R.; Rivers, M.L.; Rarback, H.; Stefan, P.M.; Spanne, P.; Luke, P.N.; Pehl, R.; Thompson, A.C.; Miller, M.

1991-01-01

A monochromatic computed tomography (CT) scanner is being developed at the X17 superconducting wiggler beamline at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, to image the human head and neck. The system configuration is one of a horizontal fan beam and an upright seated rotating subject. The purpose of the project are to demonstrate improvement in the image contrast and in the image quantitative accuracy that can be obtained in monochromatic CT and to apply the system to specific clinical research programs in neuroradiology. This paper describes the first phantom studies carried out with a prototype system, using the dual photon absorptiometry (DPA) method at energies of 20 and 39 Kev. The results show that improvements in image contrast and quantitative accuracy are possible with monochromatic DPA CT. Estimates of the clinical performance of the planned CT system are made on the basis of these initial results

Review of reconstruction of radiation incident air kerma by measurement of absorbed dose in tooth enamel with EPR

International Nuclear Information System (INIS)

Wieser, A.

2012-01-01

Electron paramagnetic resonance dosimetry with tooth enamel has been proved to be a reliable method to determine retrospectively exposures from photon fields with minimal detectable doses of 100 mGy or lower, which is lower than achievable with cytogenetic dose reconstruction methods. For risk assessment or validating dosimetry systems for specific radiation incidents, the relevant dose from the incident has to be calculated from the total absorbed dose in enamel by subtracting additional dose contributions from the radionuclide content in teeth, natural external background radiation and medical exposures. For calculating organ doses or evaluating dosimetry systems the absorbed dose in enamel from a radiation incident has to be converted to air kerma using dose conversion factors depending on the photon energy spectrum and geometry of the exposure scenario. This paper outlines the approach to assess individual dose contributions to absorbed dose in enamel and calculate individual air kerma of a radiation incident from the absorbed dose in tooth enamel. (author)

Review of reconstruction of radiation incident air kerma by measurement of absorbed dose in tooth enamel with EPR.

Science.gov (United States)

Wieser, A

2012-03-01

Electron paramagnetic resonance dosimetry with tooth enamel has been proved to be a reliable method to determine retrospectively exposures from photon fields with minimal detectable doses of 100 mGy or lower, which is lower than achievable with cytogenetic dose reconstruction methods. For risk assessment or validating dosimetry systems for specific radiation incidents, the relevant dose from the incident has to be calculated from the total absorbed dose in enamel by subtracting additional dose contributions from the radionuclide content in teeth, natural external background radiation and medical exposures. For calculating organ doses or evaluating dosimetry systems the absorbed dose in enamel from a radiation incident has to be converted to air kerma using dose conversion factors depending on the photon energy spectrum and geometry of the exposure scenario. This paper outlines the approach to assess individual dose contributions to absorbed dose in enamel and calculate individual air kerma of a radiation incident from the absorbed dose in tooth enamel.

Fluorescent X-ray computed tomography using synchrotron radiation for imaging nonradioactive tracer materials

Energy Technology Data Exchange (ETDEWEB)

Akiba, Masahiro; Yuasa, Tetsuya; Uchida, Akira; Akatsuka, Takao [Yamagata Univ., Yonezawa (Japan). Electrical and Information of Engineering; Takeda, Tohoru; Hyodo, Kazuyuki; Itai, Yuji

1997-09-01

We describe a system of fluorescent X-ray computed tomography using synchrotron radiation (SR-FXCT) to image nonradioactive contrast materials. The system operates on the basis of computed tomography (CT) scanned by the pencil beam. In the previous experiment, we have imaged an acrylic cylindrical phantom with cross-shaped channel, filled with a diluted iodine-based tracer material of 200 {mu}g/ml. This research is aimed to improve image quality, to select the optimum energy of the incident X-ray, to confirm quantitative evaluation of the image, and to demonstrate FXCT image for living body. First, we simulated output energy profile by the Monte Carlo simulation and confirmed to predetermine the incident X-ray energy at 37 keV, in order to separate the fluorescent photons from background scattering components. Next, the imaging experiment was performed by using conventional CT algorithm under the optimum parameter at the Tristan Accumulation Ring, KEK, Japan. An acrylic phantom containing five paraxial channels of 5 and 4 mm in diameter, could be imaged; where each channel was respectively filled with diluted iodine-based contrast materials of 50, 100, 200 and 500 {mu}g/ml. From the reconstructed image, we confirmed quantitativity in the FXCT image. Finally, a rat`s brain was imaged in vitro by FXCT and monochromatic transmission CT. The comparison between these results showed that the iodine-rich region in the FXCT image corresponded with that in the monochromatic transmission CT image. (author)

Orbital effects of a monochromatic plane gravitational wave with ultra-low frequency incident on a gravitationally bound two-body system

Directory of Open Access Journals (Sweden)

Lorenzo Iorio

2014-09-01

Full Text Available We analytically compute the long-term orbital variations of a test particle orbiting a central body acted upon by an incident monochromatic plane gravitational wave. We assume that the characteristic size of the perturbed two-body system is much smaller than the wavelength of the wave. Moreover, we also suppose that the wave's frequency νg is much smaller than the particle's orbital one nb. We make neither a priori assumptions about the direction of the wavevector kˆ nor on the orbital configuration of the particle. While the semi-major axis a is left unaffected, the eccentricity e, the inclination I, the longitude of the ascending node Ω, the longitude of pericenter ϖ and the mean anomaly ℳ undergo non-vanishing long-term changes of the form dΨ/dt=F(Kij;e,I,Ω,ω,Ψ=e,I,Ω,ϖ,M, where Kij, i,j=1,2,3 are the coefficients of the tidal matrix K. Thus, in addition to the variations of its orientation in space, the shape of the orbit would be altered as well. Strictly speaking, such effects are not secular trends because of the slow modulation introduced by K and by the orbital elements themselves: they exhibit peculiar long-term temporal patterns which would be potentially of help for their detection in multidecadal analyses of extended data records of planetary observations of various kinds. In particular, they could be useful in performing independent tests of the inflation-driven ultra-low gravitational waves whose imprint may have been indirectly detected in the Cosmic Microwave Background by the Earth-based experiment BICEP2. Our calculation holds, in general, for any gravitationally bound two-body system whose orbital frequency nb is much larger than the frequency νg of the external wave, like, e.g., extrasolar planets and the stars orbiting the Galactic black hole. It is also valid for a generic perturbation of tidal type with constant coefficients over timescales of the order of the orbital period of the perturbed particle.

Selecting optimal monochromatic level with spectral CT imaging for improving imaging quality in hepatic venography

International Nuclear Information System (INIS)

Sun Jun; Luo Xianfu; Wang Shou'an; Wang Jun; Sun Jiquan; Wang Zhijun; Wu Jingtao

2013-01-01

Objective: To investigate the effect of spectral CT monochromatic images for improving imaging quality in hepatic venography. Methods: Thirty patients underwent spectral CT examination on a GE Discovery CT 750 HD scanner. During portal phase, 1.25 mm slice thickness polychromatic images and optimal monochromatic images were obtained, and volume rendering and maximum intensity projection were created to show the hepatic veins respectively. The overall imaging quality was evaluated on a five-point scale by two radiologists. Inter-observer agreement in subjective image quality grading was assessed by Kappa statistics. Paired-sample t test were used to compare hepatic vein attenuation, hepatic parenchyma attenuation, CT value difference between the hepatic vein and the liver parenchyma, image noise, vein-to-liver contrast-to-noise ratio (CNR), the image quality score of hepatic venography between the two image data sets. Results: The monochromatic images at 50 keV were found to demonstrate the best CNR for hepatic vein.The hepatic vein attenuation [(329 ± 47) HU], hepatic parenchyma attenuation [(178 ± 33) HU], CT value difference between the hepatic vein and the liver parenchyma [(151 ± 33) HU], image noise (17.33 ± 4.18), CNR (9.13 ± 2.65), the image quality score (4.2 ± 0.6) of optimal monochromatic images were significantly higher than those of polychromatic images [(149 ± 18) HU], [(107 ± 14) HU], [(43 ±11) HU], 12.55 ± 3.02, 3.53 ± 1.03, 3.1 ± 0.8 (t values were 24.79, 13.95, 18.85, 9.07, 13.25 and 12.04, respectively, P < 0.01). In the comparison of image quality, Kappa value was 0.81 with optimal monochromatic images and 0.69 with polychromatic images. Conclusion: Monochromatic images of spectral CT could improve CNR for displaying hepatic vein and improve the image quality compared to the conventional polychromatic images. (authors)

Towards a Monochromatization Scheme for Direct Higgs Production at FCC-ee

CERN Document Server

Valdivia Garcia, Marco Alan; Zimmermann, Frank

2016-01-01

Direct Higgs production in e+e− collisions at the FCC is of interest if the centre-of-mass energy spread can be reduced by at least an order of magnitude. A monochromatization scheme, to accomplish this, can be realized with horizontal dispersion of opposite sign for the two colliding beams at the interaction point (IP). We recall historical approaches to monochromatization, then derive a set of IP parameters which would provide the required performance in FCC e+e− collisions at 62.5 GeV beam energy, compare these with the baseline optics parameters at neighbouring energies (45.6 and 80 GeV), comment on the effect of beamstrahlung, and indicate the modifications of the FCC-ee final-focus optics needed to obtain the required parameters.

Incidence of Second Malignancies Among Patients Treated With Proton Versus Photon Radiation

Energy Technology Data Exchange (ETDEWEB)

Chung, Christine S., E-mail: chungc1@sutterhealth.org [Department of Radiation Oncology, Alta Bates Summit Medical Center, Berkeley, California (United States); Yock, Torunn I. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Nelson, Kerrie [Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts (United States); Xu, Yang [Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts (United States); Keating, Nancy L. [Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts (United States); Department of General Internal Medicine, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Tarbell, Nancy J. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Office of the Executive Dean, Harvard Medical School, Boston, Massachusetts (United States)

2013-09-01

Purpose: Proton radiation, when compared with photon radiation, allows delivery of increased radiation dose to the tumor while decreasing dose to adjacent critical structures. Given the recent expansion of proton facilities in the United States, the long-term sequelae of proton therapy should be carefully assessed. The objective of this study was to compare the incidence of second cancers in patients treated with proton radiation with a population-based cohort of matched patients treated with photon radiation. Methods and Materials: We performed a retrospective cohort study of 558 patients treated with proton radiation from 1973 to 2001 at the Harvard Cyclotron in Cambridge, MA and 558 matched patients treated with photon therapy in the Surveillance, Epidemiology, and End Results (SEER) Program cancer registry. Patients were matched by age at radiation treatment, sex, year of treatment, cancer histology, and site. The main outcome measure was the incidence of second malignancies after radiation. Results: We matched 558 proton patients with 558 photon patients from the Surveillance, Epidemiology, and End Results registry. The median duration of follow-up was 6.7 years (interquartile range, 7.4) and 6.0 years (interquartile range, 9.3) in the proton and photon cohorts, respectively. The median age at treatment was 59 years in each cohort. Second malignancies occurred in 29 proton patients (5.2%) and 42 photon patients (7.5%). After we adjusted for sex, age at treatment, primary site, and year of diagnosis, proton therapy was not associated with an increased risk of second malignancy (adjusted hazard ratio, 0.52 [95% confidence interval, 0.32-0.85]; P=.009). Conclusions: The use of proton radiation therapy was not associated with a significantly increased risk of secondary malignancies compared with photon therapy. Longer follow-up of these patients is needed to determine if there is a significant decrease in second malignancies. Given the limitations of the study

Incidence of Second Malignancies Among Patients Treated With Proton Versus Photon Radiation

International Nuclear Information System (INIS)

Chung, Christine S.; Yock, Torunn I.; Nelson, Kerrie; Xu, Yang; Keating, Nancy L.; Tarbell, Nancy J.

2013-01-01

Purpose: Proton radiation, when compared with photon radiation, allows delivery of increased radiation dose to the tumor while decreasing dose to adjacent critical structures. Given the recent expansion of proton facilities in the United States, the long-term sequelae of proton therapy should be carefully assessed. The objective of this study was to compare the incidence of second cancers in patients treated with proton radiation with a population-based cohort of matched patients treated with photon radiation. Methods and Materials: We performed a retrospective cohort study of 558 patients treated with proton radiation from 1973 to 2001 at the Harvard Cyclotron in Cambridge, MA and 558 matched patients treated with photon therapy in the Surveillance, Epidemiology, and End Results (SEER) Program cancer registry. Patients were matched by age at radiation treatment, sex, year of treatment, cancer histology, and site. The main outcome measure was the incidence of second malignancies after radiation. Results: We matched 558 proton patients with 558 photon patients from the Surveillance, Epidemiology, and End Results registry. The median duration of follow-up was 6.7 years (interquartile range, 7.4) and 6.0 years (interquartile range, 9.3) in the proton and photon cohorts, respectively. The median age at treatment was 59 years in each cohort. Second malignancies occurred in 29 proton patients (5.2%) and 42 photon patients (7.5%). After we adjusted for sex, age at treatment, primary site, and year of diagnosis, proton therapy was not associated with an increased risk of second malignancy (adjusted hazard ratio, 0.52 [95% confidence interval, 0.32-0.85]; P=.009). Conclusions: The use of proton radiation therapy was not associated with a significantly increased risk of secondary malignancies compared with photon therapy. Longer follow-up of these patients is needed to determine if there is a significant decrease in second malignancies. Given the limitations of the study

Dichromatic laser radiation effects on DNA of Escherichia coli and plasmids

Science.gov (United States)

Martins, W. A.; Polignano, G. A. C.; Guimarães, O. R.; Geller, M.; Paoli, F.; Fonseca, A. S.

2015-04-01

Dichromatic and consecutive laser radiations have attracted increased attention for clinical applications as offering new tools for the treatment of dysfunctional tissues in situations where monochromatic radiation is not effective. This work evaluated the survival, filamentation and morphology of Escherichia coli cells, and the induction of DNA lesions, in plasmid DNA exposed to low-intensity consecutive dichromatic laser radiation. Exponential and stationary wild type and formamidopyrimidine DNA glycosylase/MutM protein deficient E. coli cultures were exposed to consecutive low-intensity dichromatic laser radiation (infrared laser immediately after red laser) to study the survival, filamentation and morphology of bacterial cells. Plasmid DNA samples were exposed to dichromatic radiation to study DNA lesions by electrophoretic profile. Dichromatic laser radiation affects the survival, filamentation and morphology of E. coli cultures depending on the growth phase and the functional repair mechanism of oxidizing lesions in DNA, but does not induce single/double strands breaks or alkali-labile DNA lesions. Results show that low-intensity consecutive dichromatic laser radiation induces biological effects that differ from those induced by monochromatic laser radiation, suggesting that other therapeutic effects could be obtained using dichromatic radiation.

Stress measurements by multi-reflection grazing-incidence X-ray diffraction method (MGIXD) using different radiation wavelengths and different incident angles

International Nuclear Information System (INIS)

Marciszko, Marianna; Baczmański, Andrzej; Braham, Chedly; Wróbel, Mirosław; Wroński, Sebastian; Cios, Grzegorz

2017-01-01

The presented study introduces the development of the multi-reflection grazing-incidence X-ray diffraction method (MGIXD) for residual stress determination. The proposed new methodology is aimed at obtaining more reliable experimental data and increasing the depth of non-destructive stress determination below the sample surface. To verify proposed method measurements were performed on a classical X-ray diffractometer (Cu Kα radiation) and using synchrotron radiation (three different wavelengths: λ = 1.2527 Å, λ = 1.5419 Å and λ = 1.7512 Å). The Al2017 alloy subjected to three different surface treatments was investigated in this study. The obtained results showed that the proposed development of MGIXD method, in which not only different incident angles but also different wavelengths of X-ray are used, can be successfully applied for residual stress determination, especially when stress gradients are present in the sample.

Brain tumors and synchrotron radiation: new methods for mini-beams radiation therapy and treatment follow-up by functional imaging

International Nuclear Information System (INIS)

Deman, P.

2012-01-01

An innovative method of synchrotron radiation therapy, called mini-beams, was proposed by A. Dilmanian et al. in 2006. Mini-beams consists in tumor irradiation with monochromatic sub-millimetric x-ray beams spatially fractionated produced by a synchrotron source. To obtain a homogeneous dose in the target volume, an interleaving is realized using two orthogonal incidences. Adjacent healthy tissue is only partially irradiated by mini-beams, the areas between the beams only receive scattered radiation and therefore the energy deposited is 10 to 15 times lower than on one mini-beam axis, leading to a sparing effect of healthy tissue even when a high dose is deposited in the target volume. The thesis project is the development of this experimental method of monochromatic mini-beams, which involves the control of the irradiation geometry, the control of dosimetry and its modeling by Monte Carlo simulations. To evaluate the method, preclinical experiments on models of brain tumors implanted in rats (F98) are performed. Follow-up by anatomical and functional imaging is carried out to evaluate the effectiveness of the treatment. Functional imaging of cerebral perfusion (volume and cerebral blood flow, mean transit time of heavy elements) appears to be associated in the literature as a relevant method for monitoring prognostic. The key parameters of the cerebral vasculature are mainly studied in magnetic resonance imaging (MRI), because of the harmlessness of this imaging modality. The relation between MRI signal and contrast agent concentration is very complex and no quantitative relationship is well known. Synchrotron Radiation Computed Tomography (SRCT) is an imaging modality with performances to measure absolute contrast agent concentration very close to the theoretical limits and can be used as gold-standard. The used pharmacokinetic models need as input parameters a contrast agent concentration versus time. A comparison of perfusion measurements between MRI and SRCT

Emergency reception of accidents and incidents in working with ionizing radiation

International Nuclear Information System (INIS)

Abrahamse, J.C.; Gispen, J.G.W.

1989-01-01

This manual is intended to be a general manual for the responsible expert regarding radiation hygienics in order to assist him in establishing an organization for combat of accidents and incidents. First attention is paid considerations underlying emergency measures and aid, subsequently the demands and desirabilities in the practical organization are discussed. (author). 3 figs

Simulating Space Radiation-Induced Breast Tumor Incidence Using Automata.

Science.gov (United States)

Heuskin, A C; Osseiran, A I; Tang, J; Costes, S V

2016-07-01

Estimating cancer risk from space radiation has been an ongoing challenge for decades primarily because most of the reported epidemiological data on radiation-induced risks are derived from studies of atomic bomb survivors who were exposed to an acute dose of gamma rays instead of chronic high-LET cosmic radiation. In this study, we introduce a formalism using cellular automata to model the long-term effects of ionizing radiation in human breast for different radiation qualities. We first validated and tuned parameters for an automata-based two-stage clonal expansion model simulating the age dependence of spontaneous breast cancer incidence in an unexposed U.S. We then tested the impact of radiation perturbation in the model by modifying parameters to reflect both targeted and nontargeted radiation effects. Targeted effects (TE) reflect the immediate impact of radiation on a cell's DNA with classic end points being gene mutations and cell death. They are well known and are directly derived from experimental data. In contrast, nontargeted effects (NTE) are persistent and affect both damaged and undamaged cells, are nonlinear with dose and are not well characterized in the literature. In this study, we introduced TE in our model and compared predictions against epidemiologic data of the atomic bomb survivor cohort. TE alone are not sufficient for inducing enough cancer. NTE independent of dose and lasting ∼100 days postirradiation need to be added to accurately predict dose dependence of breast cancer induced by gamma rays. Finally, by integrating experimental relative biological effectiveness (RBE) for TE and keeping NTE (i.e., radiation-induced genomic instability) constant with dose and LET, the model predicts that RBE for breast cancer induced by cosmic radiation would be maximum at 220 keV/μm. This approach lays the groundwork for further investigation into the impact of chronic low-dose exposure, inter-individual variation and more complex space radiation

Application of an incident taxonomy for radiation therapy: Analysis of five years of data from three integrated cancer centres.

Science.gov (United States)

Greenham, Stuart; Manley, Stephen; Turnbull, Kirsty; Hoffmann, Matthew; Fonseca, Amara; Westhuyzen, Justin; Last, Andrew; Aherne, Noel J; Shakespeare, Thomas P

2018-01-01

To develop and apply a clinical incident taxonomy for radiation therapy. Capturing clinical incident information that focuses on near-miss events is critical for achieving higher levels of safety and reliability. A clinical incident taxonomy for radiation therapy was established; coding categories were prescription, consent, simulation, voluming, dosimetry, treatment, bolus, shielding, imaging, quality assurance and coordination of care. The taxonomy was applied to all clinical incidents occurring at three integrated cancer centres for the years 2011-2015. Incidents were managed locally, audited and feedback disseminated to all centres. Across the five years the total incident rate (per 100 courses) was 8.54; the radiotherapy-specific coded rate was 6.71. The rate of true adverse events (unintended treatment and potential patient harm) was 1.06. Adverse events, where no harm was identified, occurred at a rate of 2.76 per 100 courses. Despite workload increases, overall and actual rates both exhibited downward trends over the 5-year period. The taxonomy captured previously unidentified quality assurance failures; centre-specific issues that contributed to variations in incident trends were also identified. The application of a taxonomy developed for radiation therapy enhances incident investigation and facilitates strategic interventions. The practice appears to be effective in our institution and contributes to the safety culture. The ratio of near miss to actual incidents could serve as a possible measure of incident reporting culture and could be incorporated into large scale incident reporting systems.

Survey on risk perception of radiation following an incident involving a stuck 60Co source in Henan Province, China

International Nuclear Information System (INIS)

Lei, C.; Sun, Q.; Cheng, X.; Zhang, Q.; Fu, Y.; Chu, C.; Zhao, Y.; Qin, W.; Su, X.

2012-01-01

In July 2009, an incident involving a stuck Co-60 source led hundreds of thousands of people to escape Qi County, Henan Province, China, although no medical or environmental consequences were related to the incident. To investigate knowledge about radiation, public risk-perception of radiation, and evaluation of the official response, a survey was conducted in Qi and Hui County (control). Face-to-face questionnaire interviews were conducted among three groups with different educational backgrounds. In total, 1340 valid questionnaires were collected from people interviewed. Knowledge about radiation was low in all groups in both counties, although knowledge in Qi County was higher than that in Hui County (control). More than 40 % respondents supported construction of nuclear power plants (NPPs) in China, while only a few supported constructing NPPs in their vicinity. The main reasons for the mass escape following the incident were assumed to be lack of knowledge about radiation, misinformation, the government's failure to disclose information in time and imitation of group behaviour. Over 60 % in Group I and II trusted the local government. About 64 % disapproved the response of the Qi County government. After the incident, the population in Qi County still knows little about radiation. Although people trust the government, they are dissatisfied with the response of the local government regarding the incident. (authors)

Semiclassical interaction between monochromatic electromagnetic radiation and an atom with two unstable levels; some fallacious works by Kamenov-Bonchev

International Nuclear Information System (INIS)

Romashev, Yu. A.; Skorobogatov, G.A.

1999-01-01

The solution of the time-dependent Hamiltonian for the classical dipole interaction of a two-level atom with a monochromatic electromagnetic wave is presented. Both atomic energy levels are assumed to be unstable. The amplitudes and probabilities of transitions between the energy levels as well as the cross-sections of resonance absorption and induced emission are obtained explicitly. It is shown that in both stationary and nonstationary limits the instability of the lower level does not lead to a differential cross section of induced emission larger than those obtained from the Breit-Wigner formula in the standard collision theory. (authors)

Validating FMEA output against incident learning data: A study in stereotactic body radiation therapy.

Science.gov (United States)

Yang, F; Cao, N; Young, L; Howard, J; Logan, W; Arbuckle, T; Sponseller, P; Korssjoen, T; Meyer, J; Ford, E

2015-06-01

Though failure mode and effects analysis (FMEA) is becoming more widely adopted for risk assessment in radiation therapy, to our knowledge, its output has never been validated against data on errors that actually occur. The objective of this study was to perform FMEA of a stereotactic body radiation therapy (SBRT) treatment planning process and validate the results against data recorded within an incident learning system. FMEA on the SBRT treatment planning process was carried out by a multidisciplinary group including radiation oncologists, medical physicists, dosimetrists, and IT technologists. Potential failure modes were identified through a systematic review of the process map. Failure modes were rated for severity, occurrence, and detectability on a scale of one to ten and risk priority number (RPN) was computed. Failure modes were then compared with historical reports identified as relevant to SBRT planning within a departmental incident learning system that has been active for two and a half years. Differences between FMEA anticipated failure modes and existing incidents were identified. FMEA identified 63 failure modes. RPN values for the top 25% of failure modes ranged from 60 to 336. Analysis of the incident learning database identified 33 reported near-miss events related to SBRT planning. Combining both methods yielded a total of 76 possible process failures, of which 13 (17%) were missed by FMEA while 43 (57%) identified by FMEA only. When scored for RPN, the 13 events missed by FMEA ranked within the lower half of all failure modes and exhibited significantly lower severity relative to those identified by FMEA (p = 0.02). FMEA, though valuable, is subject to certain limitations. In this study, FMEA failed to identify 17% of actual failure modes, though these were of lower risk. Similarly, an incident learning system alone fails to identify a large number of potentially high-severity process errors. Using FMEA in combination with incident learning may

Photofission of NAT Pt by monochromatic and polarized photons in the quasi-deuteron region

International Nuclear Information System (INIS)

Paiva, Eduardo de.

1992-01-01

The measurement of the Nat Pt photofission yield at 69 MeV of effective average energy of the incident photon is made using a polarized and monochromatic photon beam from the LADON system of the National Laboratory of Frascati, Italy, produced by inverse Compton scattering of laser light by high energy electrons of the ADONE Accelerator and using as fission track solid detector the Makrofol, being the developing made by usual procedure. The experimental value of the nuclear fissionability is compared to a theoretical value obtained following a model at two stages: in the first, the photon energy is absorbed by a neutron-proton pair inducing to the nucleus excitation, and in the second the nucleus de-excites due to the competition between nucleon evaporation and fission. The effect of fast nucleon emission during the first stage and the successive evaporation of neutrons in the second stage are considered. 40 refs, 12 figs, 9 tabs

Feasibility of Strong and Quasi-Monochromatic Gamma-Ray Generation by the Laser Compton Scattering

Energy Technology Data Exchange (ETDEWEB)

Lee, Jiyoung; Rehman, Haseeb ur; Kim, Yonghee [KAIST, Daejeon (Korea, Republic of)

2015-10-15

This is because LCS γ-rays are energy-tunable, quasi-monochromatic, and beam-like. The photon intensity of the mono-chromatic LCS gamma-ray should be high or strong for efficient and high transmutation rate. It was recently reported that a so-called energy-recovery linac system is able to produce a very high-intensity LCS photons in the order of approximately 1013 photons/s economically. It however did not evaluate quality of the LCS photon beam although a quasi-monoenergetic LCS beam is of huge importance in the photo-nuclear transmutation reactions. It is upon this observation that this paper was prepared. Specifically, this work attempts to quantify intensity of the quasi-monochromatic LCS beam from the said linac system. In addition, this paper aims to discuss general characteristics of the LCS photon, and possible approaches to increase its intensity. This paper presents essential characteristics of the laser Compton scattering (LCS) in terms of its photon energy, cross-section and photon intensity. By using different combinations of electron energy, laser energy and scattering angle, we can effectively generate high-intensity and highly-chromatic LCS gamma-rays. Our preliminary analyses indicate that, in view of Compton cross-section, higher-energy photon can be better generated by increasing the electron energy rather than increasing the laser energy. However, in order to maximize the intensity of monochromatic beam, the laser energy should be maximized for a targeted LCS photon energy.

The potential of dual-energy virtual monochromatic imaging in reducing renal cyst pseudoenhancement. A phantom study

International Nuclear Information System (INIS)

Yamada, Sachiko; Ueguchi, Takashi; Ukai, Isao; Nagai, Yumiko; Yamakawa, Masanobu; Shimosegawa, Eku; Shimazu, Takeshi; Hatazawa, Jun

2012-01-01

Renal cyst pseudoenhancement, an artifactual increase of computed tomography (CT) attenuation for cysts with increased iodine concentrations in the renal parenchyma, complicates the classification of cysts and may thus lead to the mischaracterization of a benign non-enhancing lesion as an enhancing mass. The purpose of this study was to use a phantom model to assess the ability of dual-energy virtual monochromatic imaging to reduce renal pseudoenhancement. A water-filled cylindrical cyst model suspended in varying concentrations of iodine solution, to simulate varying levels of parenchymal enhancement, was scanned with a dual-energy CT scanner using the following three scanning protocols with different combinations of tube voltage: 80 and 140 kV; 80 and 140 kV with tin filter; and 100 and 140 kV with tin filter. Virtual monochromatic images were then synthesized for each dual-energy scan. Single-energy scan with a tube voltage of 120 kV was also performed to obtain polychromatic images as controls. Mean attenuation values (in Hounsfield units) of cyst proxies were measured on both polychromatic and virtual monochromatic images. Pseudoenhancement was considered to be present when the cyst attenuation level increased by more than 10 HU (Hounsfield Unit) as the background iodine concentration increased from 0.0% to 0.4%, 1.5%, or 2.5%. Our results revealed that pseudoenhancement was not observed on any of the monochromatic images, but appeared on polychromatic images at a background iodine concentration of 2.5%. We thus conclude that dual-energy virtual monochromatic images have a potential to reduce renal pseudoenhancement. (author)

Radiative defluorination of poly (vinylidene fluoride) under soft X-ray radiation

International Nuclear Information System (INIS)

Chebotaryov, S.S.; Baitinger, E.M.; Volegov, A.A.; Margamov, I.G.; Gribov, I.V.; Moskvina, N.A.; Kuznetsov, V.L.; Evsyukov, S.E.; Pesin, L.A.

2006-01-01

The rates of poly (vinylidene fluoride) (PVDF) degradation under synchrotron (SR) and conventional X-ray radiation have been measured and compared. NEXAFS spectra of fluorine show significant changes in their shape and intensity with elevation of radiation dose (or duration of SR exposure). Non-monochromatic AlK α radiation and the flow of secondary electrons accompanying it also cause surface degradation of PVDF. XPS allows one to measure relative content of fluorine by three ways: via relative intensities of F2s/C1s, F1s/C1s, spectra and using the features arising due to of C1s peaks in CF 2 and CF groups

Radiating low back pain in general practice : Incidence, prevalence, diagnosis, and long-term clinical course of illness

NARCIS (Netherlands)

Spijker-Huiges, Antje; Groenhof, Feikje; Winters, Jan C.; van Wijhe, Marten; Groenier, Klaas H.; van der Meer, Klaas

Objective. The aim of this study was to calculate the incidence and prevalence of radiating low back pain, to explore the long-term clinical course of radiating low back pain including the influence of radiculopathy (in a subsample of the study population) and non-radiating low back pain thereon,

Inelastic neutron scattering experiments with the monochromatic imaging mode of the RITA-II spectrometer

International Nuclear Information System (INIS)

Bahl, C.R.H.; Lefmann, K.; Abrahamsen, A.B.; Ronnow, H.M.; Saxild, F.; Jensen, T.B.S.; Udby, L.; Andersen, N.H.; Christensen, N.B.; Jakobsen, H.S.; Larsen, T.; Haefliger, P.S.; Streule, S.; Niedermayer, Ch.

2006-01-01

Recently a monochromatic multiple data taking mode has been demonstrated for diffraction experiments using a RITA type cold neutron spectrometer with a multi-bladed analyser and a position-sensitive detector. Here, we show how this mode can be used in combination with a flexible radial collimator to perform real inelastic neutron scattering experiments. We present the results from inelastic powder, single crystal dispersion and single crystal constant energy mapping experiments. The advantages and complications of performing these experiments are discussed along with a comparison between the imaging mode and the traditional monochromatic focussing mode

Inelastic neutron scattering experiments with the monochromatic imaging mode of the RITA-II spectrometer

Energy Technology Data Exchange (ETDEWEB)

Bahl, C.R.H. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark) and Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark)]. E-mail: christian.bahl@risoe.dk; Lefmann, K. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: kim.lefmann@risoe.dk; Abrahamsen, A.B. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Ronnow, H.M. [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Saxild, F. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Jensen, T.B.S. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Udby, L. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Andersen, N.H. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Christensen, N.B. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Jakobsen, H.S. [Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, DK-2100 Copenhagen (Denmark); Larsen, T. [Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, DK-2100 Copenhagen (Denmark); Haefliger, P.S. [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Streule, S.; Niedermayer, Ch. [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

2006-05-15

Recently a monochromatic multiple data taking mode has been demonstrated for diffraction experiments using a RITA type cold neutron spectrometer with a multi-bladed analyser and a position-sensitive detector. Here, we show how this mode can be used in combination with a flexible radial collimator to perform real inelastic neutron scattering experiments. We present the results from inelastic powder, single crystal dispersion and single crystal constant energy mapping experiments. The advantages and complications of performing these experiments are discussed along with a comparison between the imaging mode and the traditional monochromatic focussing mode.

Observed linkages between the northern annular mode/North Atlantic Oscillation, cloud incidence, and cloud radiative forcing

Science.gov (United States)

Li, Ying; Thompson, David W. J.; Huang, Yi; Zhang, Minghong

2014-03-01

The signature of the northern annular mode/North Atlantic Oscillation (NAM/NAO) in the vertical and horizontal distribution of tropospheric cloudiness is investigated in CloudSat and CALIPSO data from June 2006 to April 2011. During the Northern Hemisphere winter, the positive polarity of the NAM/NAO is marked by increases in zonally averaged cloud incidence north of ~60°N, decreases between ~25 and 50°N, and increases in the subtropics. The tripolar-like anomalies in cloud incidence associated with the NAM/NAO are largest over the North Atlantic Ocean basin/Middle East and are physically consistent with the NAM/NAO-related anomalies in vertical motion. Importantly, the NAM/NAO-related anomalies in tropospheric cloud incidence lead to significant top of atmosphere cloud radiative forcing anomalies that are comparable in amplitude to those associated with the NAM/NAO-related temperature anomalies. The results provide observational evidence that the most prominent pattern of Northern Hemisphere climate variability is significantly linked to variations in cloud radiative forcing. Implications for two-way feedback between extratropical dynamics and cloud radiative forcing are discussed.

Incident solar radiation and coronary heart disease mortality rates in Europe

International Nuclear Information System (INIS)

Wong, Alfred

2008-01-01

The reported low mortality rate from coronary heart disease in Portugal, Spain, Italy, Greece, and France, to a lesser extent, has been attributed in numerous nutritional studies to the consumption of a Mediterranean-type diet. There are still many unresolved issues about the direct causal effect of the Mediterranean dietary regime on low incidence of coronary heart disease. An analysis of coronary heart disease mortality rates in Europe from a latitudinal gradient perspective has shown to have a close correlation to incident solar radiation. It is surmised that the resulting increased in situ biosynthesis of Vitamin D 3 could be the critical missing confounder in the analysis of the beneficial health outcome of the Mediterranean diet

The Response of the Ocean Thermal Skin Layer to Variations in Incident Infrared Radiation

Science.gov (United States)

Wong, Elizabeth W.; Minnett, Peter J.

2018-04-01

Ocean warming trends are observed and coincide with the increase in concentrations of greenhouse gases in the atmosphere resulting from human activities. At the ocean surface, most of the incoming infrared (IR) radiation is absorbed within the top micrometers of the ocean's surface where the thermal skin layer (TSL) exists. Thus, the incident IR radiation does not directly heat the upper few meters of the ocean. This paper investigates the physical mechanism between the absorption of IR radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that given the heat lost through the air-sea interface is controlled by the TSL, the TSL adjusts in response to variations in incident IR radiation to maintain the surface heat loss. This modulates the flow of heat from below and hence controls upper ocean heat content. This hypothesis is tested using the increase in incoming longwave radiation from clouds and analyzing vertical temperature profiles in the TSL retrieved from sea-surface emission spectra. The additional energy from the absorption of increasing IR radiation adjusts the curvature of the TSL such that the upward conduction of heat from the bulk of the ocean into the TSL is reduced. The additional energy absorbed within the TSL supports more of the surface heat loss. Thus, more heat beneath the TSL is retained leading to the observed increase in upper ocean heat content.

The change in color matches with retinal angle of incidence of the colorimeter beams.

Science.gov (United States)

Alpern, M; Kitahara, H; Fielder, G H

1987-01-01

Differences between W.D.W. chromaticities of monochromatic lights obtained with all colorimeter beams incident on the retina "off-axis" and those found for lights striking the retina normally have been studied throughout the visible spectrum on 4 normal trichromats. The results are inconsistent with: (i) the assumption in Weale's theories of the Stiles-Crawford hue shift that the sets of absorption spectra of the visual pigments catching normally and obliquely incident photons are identical, and (ii) "self-screening" explanations for the change in color with angle of incidence on the retina. The color matching functions of a protanomalous trichromat are inconsistent with the hypothesis that the absorption spectra of the visual pigments catching normally incident photons in his retina are those catching obliquely incident photons in the normal retina.

An evaluation of early countermeasures to reduce the risk of internal radiation exposure after the Fukushima nuclear incident in Japan.

Science.gov (United States)

Nomura, Shuhei; Tsubokura, Masaharu; Gilmour, Stuart; Hayano, Ryugo S; Watanabe, Yuni N; Kami, Masahiro; Kanazawa, Yukio; Oikawa, Tomoyoshi

2016-05-01

After a radiation-release incident, intake of radionuclides in the initial stage immediately following the incident may be the major contributor to total internal radiation exposure for individuals in affected areas. However, evaluation of early internal contamination risk is greatly lacking. This study assessed the relationship between initial stage evacuation/indoor sheltering and internal radiation contamination levels 4 months after the 2011 Fukushima nuclear incident in Japan and estimated potential pathways of the contamination. The study population comprised 525 participants in the internal radiation screening program at Minamisoma Municipal General Hospital, 23 km north of the Fukushima nuclear plant. The analysed dataset included the results of a screening performed in July 2011, 4 months after the incident, and of a questionnaire on early-incident response behaviours, such as sheltering indoors and evacuations, completed by participants. Association between such early countermeasures and internal contamination levels of cesium-134 were assessed using Tobit multiple regression analyses. Our study shows that individuals who evacuated to areas outside Fukushima Prefecture had similar contamination levels of cesium-134 to individuals who stayed in Fukushima (relative risk: 0.86; 95% confidence interval: 0.74-0.99). Time spent outdoors had no significant relationship with contamination levels. The effects of inhalation from radiological plumes released from the nuclear plant on total internal radiation contamination might be so low as to be undetectable by the whole-body counting unit used to examine participants. Given the apparent limited effectiveness of evacuation and indoor sheltering on internal contamination, the decision to implement such early responses to a radiation-release incident should be made by carefully balancing their potential benefits and health risks. © The Author 2015. Published by Oxford University Press. All rights reserved. For

The effects of ultraviolet-A radiation on visual evoked potentials in the young human eye

International Nuclear Information System (INIS)

Sanford, B.E.; Beacham, S.; Hanifin, J.P.; Hannon, P.; Streletz, L.; Sliney, D.; Brainard, G.C.

1996-01-01

A recent study from this laboratory using visual evoked potentials (VEPs) demonstrated that children's eyes are capable of detecting ultraviolet radiation. The aim of this study was to compare dose-response relationships in two age groups, 6-10 years (n=10) and 20-25 years (n=10). Under photopic viewing conditions (550 lux), exposures of monochromatic UV-A (339 nm) and visible radiation (502 nm) were correlated to VEPs. The results demonstrate that monochromatic UV-A can elicit age and dose dependent responses in the human visual system, suggesting that the eyes of children are more responsive to UV stimuli than the eyes of young adults. (au) 17 refs

Sample Environment in Experiments using X-Ray Synchrotron Radiation

DEFF Research Database (Denmark)

Buras, B

1984-01-01

beam experiments with wavelength chosen at will from the continuous spectrum. Another type of insertion device, called undulator produces quasi-monochromatic radiation. The insertion devices enable the tailoring of the emitted S.R. to the requirements of the users and can be treated as the first......Modern electron (positron) storage rings are able to emit very intense X-ray radiation with a continuous spectrum extending to 0.1 A, from bending magnets and insertion devices (wavelength shifters and multipole wigglers). It can be used directly for white beam experiments and/or for monochromatic...... optical element of the beam line. This feature is especially important for experiments with samples in special environment because the latter imposes limitations both on scattering and absorption experiments. However, these limitations can be minimized in each case by finding the best match between...

Infant Brain Tumors: Incidence, Survival, and the Role of Radiation Based on Surveillance, Epidemiology, and End Results (SEER) Data

International Nuclear Information System (INIS)

Bishop, Andrew J.; McDonald, Mark W.; Chang, Andrew L.; Esiashvili, Natia

2012-01-01

Purpose: To evaluate the incidence of infant brain tumors and survival outcomes by disease and treatment variables. Methods and Materials: The Surveillance, Epidemiology, and End Results (SEER) Program November 2008 submission database provided age-adjusted incidence rates and individual case information for primary brain tumors diagnosed between 1973 and 2006 in infants less than 12 months of age. Results: Between 1973 and 1986, the incidence of infant brain tumors increased from 16 to 40 cases per million (CPM), and from 1986 to 2006, the annual incidence rate averaged 35 CPM. Leading histologies by annual incidence in CPM were gliomas (13.8), medulloblastoma and primitive neuroectodermal tumors (6.6), and ependymomas (3.6). The annual incidence was higher in whites than in blacks (35.0 vs. 21.3 CPM). Infants with low-grade gliomas had the highest observed survival, and those with atypical teratoid rhabdoid tumors (ATRTs) or primary rhabdoid tumors of the brain had the lowest. Between 1979 and 1993, the annual rate of cases treated with radiation within the first 4 months from diagnosis declined from 20.5 CPM to <2 CPM. For infants with medulloblastoma, desmoplastic histology and treatment with both surgery and upfront radiation were associated with improved survival, but on multivariate regression, only combined surgery and radiation remained associated with improved survival, with a hazard ratio for death of 0.17 compared with surgery alone (p = 0.005). For ATRTs, those treated with surgery and upfront radiation had a 12-month survival of 100% compared with 24.4% for those treated with surgery alone (p = 0.016). For ependymomas survival was higher in patients treated in more recent decades (p = 0.001). Conclusion: The incidence of infant brain tumors has been stable since 1986. Survival outcomes varied markedly by histology. For infants with medulloblastoma and ATRTs, improved survival was observed in patients treated with both surgery and early radiation

Leakage of an irradiator source: The June 1988 Georgia RSI [Radiation Sterilizers, Inc.] incident

International Nuclear Information System (INIS)

1990-02-01

On June 6, 1988, operators of a pool irradiator in Decatur, Georgia, were prevented by a safety system from raising sources from the pool. Radiation levels of 60 millirem per hour at the surface of the pool water were found, indicative of a leak of one or more of the 252 Cs-137 source capsules used at the irradiator. A summary of the Incident Evaluation Task Force's First Interim Report has been prepared for person's needing an overview of the incident and lessons learned to date. This report provides a summary of Agreement States' views and recommendations on some of the issues raised by the incident

Effect of incident beam and diffuse radiation on par absorption, photosynthesis and transpiration of sitka spruce - a simulation study

International Nuclear Information System (INIS)

Wang, Y.P.; Jarvis, P.G.

1990-01-01

A simulation model, Maestro, is used to study the influence of beam fraction in the incident radiation and the radiance distribution of the sky diffuse radiation on PAR absorption, photosynthesis and transpiration of a Sitka spruce (Picea sitchensis (Bong.) Carr) tree crown. It is concluded that inaccurate separation of beam and diffuse radiation leads to significant errors in estimating the amounts of PAR absorbed, photosynthesis and transpiration by a tree in the stand. Much more attention should be paid to adequate descriptions of the radiance distribution of the sky diffuse radiation under different sky conditions. A useful approach is proposed for simulating the incident global radiaiton in a physiological, process-based model

Single source dual energy CT: What is the optimal monochromatic energy level for the analysis of the lung parenchyma?

Energy Technology Data Exchange (ETDEWEB)

Ohana, M., E-mail: mickael.ohana@gmail.com [iCube Laboratory, Université de Strasbourg/CNRS, UMR 7357, 67400 Illkirch (France); Service de Radiologie B, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg, 1 place de l’hôpital, 67000 Strasbourg (France); Labani, A., E-mail: aissam.labani@chru-strasbourg.fr [Service de Radiologie B, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg, 1 place de l’hôpital, 67000 Strasbourg (France); Severac, F., E-mail: francois.severac@chru-strasbourg.fr [Département de Biostatistiques et d’Informatique Médicale, Hôpital Civil – Hôpitaux Universitaires de Strasbourg,1 place de l’hôpital, 67000 Strasbourg (France); Jeung, M.Y., E-mail: Mi-Young.Jeung@chru-strasbourg.fr [Service de Radiologie B, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg, 1 place de l’hôpital, 67000 Strasbourg (France); Gaertner, S., E-mail: Sebastien.Gaertner@chru-strasbourg.fr [Service de Médecine Vasculaire, Nouvel Hôpital Civil – Hôpitaux Universitaires de Strasbourg,1 place de l’hôpital, 67000 Strasbourg (France); and others

2017-03-15

Highlights: • Lung parenchyma aspect varies with the monochromatic energy level in spectral CT. • Optimal diagnostic and image quality is obtained at 50–55 keV. • Mediastinum and parenchyma could be read on the same monochromatic energy level. - Abstract: Objective: To determine the optimal monochromatic energy level for lung parenchyma analysis in spectral CT. Methods: All 50 examinations (58% men, 64.8 ± 16yo) from an IRB-approved prospective study on single-source dual energy chest CT were retrospectively included and analyzed. Monochromatic images in lung window reconstructed every 5 keV from 40 to 140 keV were independently assessed by two chest radiologists. Based on the overall image quality and the depiction/conspicuity of parenchymal lesions, each reader had to designate for every patient the keV level providing the best diagnostic and image quality. Results: 72% of the examinations exhibited parenchymal lesions. Reader 1 picked the 55 keV monochromatic reconstruction in 52% of cases, 50 in 30% and 60 in 18%. Reader 2 chose 50 keV in 52% cases, 55 in 40%, 60 in 6% and 40 in 2%. The 50 and 55 keV levels were chosen by at least one reader in 64% and 76% of all patients, respectively. Merging 50 and 55 keV into one category results in an optimal setting selected by reader 1 in 82% of patients and by reader 2 in 92%, with a 74% concomitant agreement. Conclusion: The best image quality for lung parenchyma in spectral CT is obtained with the 50–55 keV monochromatic reconstructions.

MO-G-BRE-09: Validating FMEA Against Incident Learning Data: A Study in Stereotactic Body Radiation Therapy

International Nuclear Information System (INIS)

Yang, F; Cao, N; Young, L; Howard, J; Sponseller, P; Logan, W; Arbuckle, T; Korssjoen, T; Meyer, J; Ford, E

2014-01-01

Purpose: Though FMEA (Failure Mode and Effects Analysis) is becoming more widely adopted for risk assessment in radiation therapy, to our knowledge it has never been validated against actual incident learning data. The objective of this study was to perform an FMEA analysis of an SBRT (Stereotactic Body Radiation Therapy) treatment planning process and validate this against data recorded within an incident learning system. Methods: FMEA on the SBRT treatment planning process was carried out by a multidisciplinary group including radiation oncologists, medical physicists, and dosimetrists. Potential failure modes were identified through a systematic review of the workflow process. Failure modes were rated for severity, occurrence, and detectability on a scale of 1 to 10 and RPN (Risk Priority Number) was computed. Failure modes were then compared with historical reports identified as relevant to SBRT planning within a departmental incident learning system that had been active for two years. Differences were identified. Results: FMEA identified 63 failure modes. RPN values for the top 25% of failure modes ranged from 60 to 336. Analysis of the incident learning database identified 33 reported near-miss events related to SBRT planning. FMEA failed to anticipate 13 of these events, among which 3 were registered with severity ratings of severe or critical in the incident learning system. Combining both methods yielded a total of 76 failure modes, and when scored for RPN the 13 events missed by FMEA ranked within the middle half of all failure modes. Conclusion: FMEA, though valuable, is subject to certain limitations, among them the limited ability to anticipate all potential errors for a given process. This FMEA exercise failed to identify a significant number of possible errors (17%). Integration of FMEA with retrospective incident data may be able to render an improved overview of risks within a process

Parametric plasma surface instabilities with s-polarized radiation

International Nuclear Information System (INIS)

Rappaport, H.L.

1994-01-01

The authors argue that parametric plasma surface mode excitation is a viable broadband instability mechanism in the microwave regime since the wavelength of incident radiation ca be large compared to plasma ion density gradient scale lengths. They restrict their attention to plasmas which are uniform in the planes perpendicular to the density gradients. The boundary is characterized by three parameters: (1) the ion density gradient scale length, (2) the electron Debye length, and (3) the excursion of boundary electrons as they move in response to monochromatic radiation. For s-polarized radiation, equilibrium fluid motion is parallel to the boundary when the ratio of the pump quiver velocity to the speed of light is small. In this case, an abruptly bounded plasma may be modeled with no transition width. If in this case the cold fluid approximation is used as well, the specular and diffuse boundary approximations become the same. A new formation is presented in which pump induced perturbations are expressed as an explicit superposition of linear and non-linear plasma half-space modes. A four-wave interaction is found to produce instability as well as surface wave frequency-shift. This mode is compared against other modes known to exist in this geometry. The theory of surface wave linear mode conversion is reviewed with special attention paid to power flow and energy conservation in this system

X-ray radiation channeling in micro-channel plates: Spectroscopy with a synchrotron radiation beam

International Nuclear Information System (INIS)

Mazuritskiy, M.I.; Dabagov, S.B.; Marcelli, A.; Dziedzic-Kocurek, K.; Lerer, A.M.

2015-01-01

We present here the angular distribution of the radiation propagated inside MultiChannel Plates with micro-channels of ∼3 μm diameter. The spectra collected at the exit of the channels present a complex distribution with contributions that can be assigned to the fluorescence radiation, originated from the excitation of the micro-channel walls. For radiation above the absorption edge, when the monochromatic energy in the region of the Si L-edge hits the micro-channel walls with a grazing angle θ ⩾ 5°, or at the O K-edge when θ ⩾ 2° a fluorescence radiation is detected. Additional information associated to the fine structures of the XANES spectra detected at the exit of MCPs are also presented and discussed

Monochromatic Minibeams Radiotherapy: From Healthy Tissue-Sparing Effect Studies Toward First Experimental Glioma Bearing Rats Therapy

International Nuclear Information System (INIS)

Deman, Pierre; Vautrin, Mathias; Edouard, Magali; Stupar, Vasile; Bobyk, Laure; Farion, Régine; Elleaume, Hélène; Rémy, Chantal; Barbier, Emmanuel L.; Estève, François; Adam, Jean-François

2012-01-01

Purpose: The purpose of this study was to evaluate high-dose single fraction delivered with monochromatic X-rays minibeams for the radiotherapy of primary brain tumors in rats. Methods and Materials: Two groups of healthy rats were irradiated with one anteroposterior minibeam incidence (four minibeams, 123 Gy prescribed dose at 1 cm depth in the brain) or two interleaved incidences (54 Gy prescribed dose in a 5 × 5 × 4.8 mm 3 volume centered in the right hemisphere), respectively. Magnetic resonance imaging (MRI) follow-up was performed over 1 year. T2-weighted (T2w) images, apparent diffusion coefficient (ADC), and blood vessel permeability maps were acquired. F98 tumor bearing rats were also irradiated with interleaved minibeams to achieve a homogeneous dose of 54 Gy delivered to an 8 × 8 × 7.8 mm 3 volume centered on the tumor. Anatomic and functional MRI follow-up was performed every 10 days after irradiation. T2w images, ADC, and perfusion maps were acquired. Results: All healthy rats were euthanized 1 year after irradiation without any clinical alteration visible by simple examination. T2w and ADC measurements remain stable for the single incidence irradiation group. Localized Gd-DOTA permeability, however, was observed 9 months after irradiation for the interleaved incidences group. The survival time of irradiated glioma bearing rats was significantly longer than that of untreated animals (49 ± 12.5 days versus 23.3 ± 2 days, p < 0.001). The tumoral cerebral blood flow and blood volume tend to decrease after irradiation. Conclusions: This study demonstrates the sparing effect of minibeams on healthy tissue. The increased life span achieved for irradiated glioma bearing rats was similar to the one obtained with other radiotherapy techniques. This experimental tumor therapy study shows the feasibility of using X-ray minibeams with high doses in brain tumor radiotherapy.

Immune responsiveness and incidence of reticulum cell sarcoma in long-term syngeneic radiation chimeras

International Nuclear Information System (INIS)

Adorini, L.; Gorini, G.; Covelli, V.; Ballardin, E.; di Michele, A.; Bassani, B.; Metalli, P.; Doria, G.

1976-01-01

Long-term syngeneic radiation chimeras displayed a very low incidence of reticulum cell sarcoma as compared with control mice. Immune reactivity of these animals was studied in vivo by anti-dinitrophenyl antibody titer and affinity and in vitro by mitotic responsiveness to phytohemagglutinin, concanavalin A and lipopolysaccharide. Antibody titer and affinity as well as the response to T lectins were found to be increased in chimeras. These results were attributed to increased function of mature T2 cells, which could explain the reduced incidence of reticulum cell sarcoma in chimeras

Error sources in the real-time NLDAS incident surface solar radiation and an evaluation against field observations and the NARR

Science.gov (United States)

Park, G.; Gao, X.; Sorooshian, S.

2005-12-01

The atmospheric model is sensitive to the land surface interactions and its coupling with Land surface Models (LSMs) leads to a better ability to forecast weather under extreme climate conditions, such as droughts and floods (Atlas et al. 1993; Beljaars et al. 1996). However, it is still questionable how accurately the surface exchanges can be simulated using LSMs, since terrestrial properties and processes have high variability and heterogeneity. Examinations with long-term and multi-site surface observations including both remotely sensed and ground observations are highly needed to make an objective evaluation on the effectiveness and uncertainty of LSMs at different circumstances. Among several atmospheric forcing required for the offline simulation of LSMs, incident surface solar radiation is one of the most significant components, since it plays a major role in total incoming energy into the land surface. The North American Land Data Assimilation System (NLDAS) and North American Regional Reanalysis (NARR) are two important data sources providing high-resolution surface solar radiation data for the use of research communities. In this study, these data are evaluated against field observations (AmeriFlux) to identify their advantages, deficiencies and sources of errors. The NLDAS incident solar radiation shows a pretty good agreement in monthly mean prior to the summer of 2001, while it overestimates after the summer of 2001 and its bias is pretty close to the EDAS. Two main error sources are identified: 1) GOES solar radiation was not used in the NLDAS for several months in 2001 and 2003, and 2) GOES incident solar radiation when available, was positively biased in year 2002. The known snow detection problem is sometimes identified in the NLDAS, since it is inherited from GOES incident solar radiation. The NARR consistently overestimates incident surface solar radiation, which might produce erroneous outputs if used in the LSMs. Further attention is given to

Higher order monochromatic aberrations of the human infant eye

OpenAIRE

Wang, Jingyun; Candy, T. Rowan

2005-01-01

The monochromatic optical aberrations of the eye degrade retinal image quality. Any significant aberrations during postnatal development could contribute to infants’ immature visual performance and provide signals for the control of eye growth. Aberrations of human infant eyes from 5 to 7 weeks old were compared with those of adult subjects using a model of an adultlike infant eye that accounted for differences in both eye and pupil size. Data were collected using the COAS Shack-Hartmann wave...

Optimal Monochromatic Energy Levels in Spectral CT Pulmonary Angiography for the Evaluation of Pulmonary Embolism

Science.gov (United States)

Wu, Huawei; Zhang, Qing; Hua, Jia; Hua, Xiaolan; Xu, Jianrong

2013-01-01

Background The aim of this study was to determine the optimal monochromatic spectral CT pulmonary angiography (sCTPA) levels to obtain the highest image quality and diagnostic confidence for pulmonary embolism detection. Methods The Institutional Review Board of the Shanghai Jiao Tong University School of Medicine approved this study, and written informed consent was obtained from all participating patients. Seventy-two patients with pulmonary embolism were scanned with spectral CT mode in the arterial phase. One hundred and one sets of virtual monochromatic spectral (VMS) images were generated ranging from 40 keV to 140 keV. Image noise, clot diameter and clot to artery contrast-to-noise ratio (CNR) from seven sets of VMS images at selected monochromatic levels in sCTPA were measured and compared. Subjective image quality and diagnostic confidence for these images were also assessed and compared. Data were analyzed by paired t test and Wilcoxon rank sum test. Results The lowest noise and the highest image quality score for the VMS images were obtained at 65 keV. The VMS images at 65 keV also had the second highest CNR value behind that of 50 keV VMS images. There was no difference in the mean noise and CNR between the 65 keV and 70 keV VMS images. The apparent clot diameter correlated with the keV levels. Conclusions The optimal energy level for detecting pulmonary embolism using dual-energy spectral CT pulmonary angiography was 65–70 keV. Virtual monochromatic spectral images at approximately 65–70 keV yielded the lowest image noise, high CNR and highest diagnostic confidence for the detection of pulmonary embolism. PMID:23667583

Pilot Study for the Creation of a European Union Radiation Accident and Incident Data Exchange System (EURAIDE)

International Nuclear Information System (INIS)

Stewart, J.E.; Lefaure, C; Czarwinski, R.

2004-01-01

This study has had the objective of evaluating the feasibility of: (i) facilitating the establishment of national radiation accident and incident databases where there are none and to encourage the compatibility of such databases, (ii) establishing a European network to exchange radiological protection feedback from accidents and incidents, (iii) establishing summary reports of relevant accidents and incidents with the aim of identifying lessons to be learned, so that they can be used in radiation protection training programs, and (iv) upgrading the radiological safety in the countries applying to join the EU, by integrating them into the above efficient feedback exchange system. This report details the first stage of the project, which was to review the status of existing (or proposed) national mechanisms for collating data on radiation incidents. The objectives of this initial review were to: i) obtain detailed information regarding the means of capturing and collating data, the format of established or proposed data systems and accessibility of the final data, ii) to use this information to consider how a European platform to gather relevant data/accident reports might be established., and iii) to consider how the various elements of national data systems might be harmonised in order to facilitate the presentation and distribution of lessons learned. It was considered that the key aspects that would need to be addressed in order to determine the feasibility of a European wide data exchange mechanism were: - the criteria used for the classification and categorisation of incidents, - criteria for the selection of incidents from national data systems for inclusion in a European-wide system, - the implication of possible language problems. In order to illicit the required information a detailed questionnaire was sent to a total of 31 countries, being existing European Member States, applicant or associated countries. A full list of the countries and institutions

A management plan for hospitals and medical centers facing radiation incidents.

Science.gov (United States)

Davari, Fereshteh; Zahed, Arash

2015-09-01

Nowadays, application of nuclear technology in different industries has largely expanded worldwide. Proportionately, the risk of nuclear incidents and the resulting injuries have, therefore, increased in recent years. Preparedness is an important part of the crisis management cycle; therefore efficient preplanning seems crucial to any crisis management plan. Equipped with facilities and experienced personnel, hospitals naturally engage with the response to disasters. The main purpose of our study was to present a practical management pattern for hospitals and medical centers in case they encounter a nuclear emergency. In this descriptive qualitative study, data were collected through experimental observations, sources like Safety manuals released by the International Atomic Energy Agency and interviews with experts to gather their ideas along with Delphi method for polling, and brainstorming. In addition, the 45 experts were interviewed on three targeted using brainstorming and Delphi method. We finally proposed a management plan along with a set of practicality standards for hospitals and medical centers to optimally respond to nuclear medical emergencies when a radiation incident happens nearby. With respect to the great importance of preparedness against nuclear incidents adoption and regular practice of nuclear crisis management codes for hospitals and medical centers seems quite necessary.

Nonlinear behavior of a monochromatic wave in a one-dimensional Vlasov plasma

International Nuclear Information System (INIS)

Shoucri, M.M.; Gagne, R.R.J.

1978-01-01

The nonlinear evolution of a monochromatic wave in a one-dimensional Vlasov plasma is studied numerically. The numerical results are carried out far enough in time for phase mixing to dominate the asymptotic state of the system. A qualitative comparison with previously reported simulations is given

Poster - 27: Incident Learning Practices in Ontario

Energy Technology Data Exchange (ETDEWEB)

Angers, Crystal; Medlam, Gaylene; Liszewski, Brian; Simniceanu, Carina [The Ottawa Hospital Cancer Centre, Mississauga Halton/Central West Regional Cancer Center, Odette Cancer Centre, Cancer Care Ontario (Canada)

2016-08-15

Purpose: The Radiation Incident and Safety Committee (RISC), established and supported by Cancer Care Ontario (CCO), is responsible for advising the Provincial Head of the Radiation Treatment program on matters relating to provincial reporting of radiation incidents with the goal of improved risk mitigation. Methods: The committee is made up of Radiation Incident Leads (RILs) with representation from each of the 14 radiation medicine programs in the province. RISC routinely meets to review recent critical incidents and to discuss provincial reporting processes and future directions of the committee. Regular face to face meetings have provided an excellent venue for sharing incident learning practices. A summary of the incident learning practices across Ontario has been compiled. Results: Almost all programs in Ontario employ an incident learning committee to review incidents and identify corrective actions or process improvements. Tools used for incident reporting include: paper based reporting, a number of different commercial products and software solutions developed in-house. A wide range of classification schema (data taxonomies) are employed, although most have been influenced by national guidance documents. The majority of clinics perform root cause analyses but utilized methodologies vary significantly. Conclusions: Most programs in Ontario employ a committee approach to incident learning. However, the reporting tools and taxonomies in use vary greatly which represents a significant challenge to provincial reporting. RISC is preparing to adopt the National System for Incident Reporting – Radiation Therapy (NSIR-RT) which will standardize incident reporting and facilitate data analyses aimed at identifying targeted improvement initiatives.

Poster - 27: Incident Learning Practices in Ontario

International Nuclear Information System (INIS)

Angers, Crystal; Medlam, Gaylene; Liszewski, Brian; Simniceanu, Carina

2016-01-01

Purpose: The Radiation Incident and Safety Committee (RISC), established and supported by Cancer Care Ontario (CCO), is responsible for advising the Provincial Head of the Radiation Treatment program on matters relating to provincial reporting of radiation incidents with the goal of improved risk mitigation. Methods: The committee is made up of Radiation Incident Leads (RILs) with representation from each of the 14 radiation medicine programs in the province. RISC routinely meets to review recent critical incidents and to discuss provincial reporting processes and future directions of the committee. Regular face to face meetings have provided an excellent venue for sharing incident learning practices. A summary of the incident learning practices across Ontario has been compiled. Results: Almost all programs in Ontario employ an incident learning committee to review incidents and identify corrective actions or process improvements. Tools used for incident reporting include: paper based reporting, a number of different commercial products and software solutions developed in-house. A wide range of classification schema (data taxonomies) are employed, although most have been influenced by national guidance documents. The majority of clinics perform root cause analyses but utilized methodologies vary significantly. Conclusions: Most programs in Ontario employ a committee approach to incident learning. However, the reporting tools and taxonomies in use vary greatly which represents a significant challenge to provincial reporting. RISC is preparing to adopt the National System for Incident Reporting – Radiation Therapy (NSIR-RT) which will standardize incident reporting and facilitate data analyses aimed at identifying targeted improvement initiatives.

Parametric plasma surface instabilities with p-polarized radiation

International Nuclear Information System (INIS)

Rappaport, H.L.

1994-01-01

The authors argue that parametric plasma surface mode excitation is a viable broadband instability mechanism in the microwave regime since the wavelength of incident radiation can be large compared to plasma ion density gradient scale lengths. The authors restrict their attention to plasmas which are uniform in the planes perpendicular to the density gradients. The boundary region is characterized by three parameters: (1) the ion density gradient length; (2) the electron Debye length; and (3) the excursion of boundary electrons as they move in response to monochromatic p-polarized radiation. A thin vacuum plasma transition layer, in which the ion density gradient scale length is large compared with the Debye length and the electron excursion, is included in the analysis of plasma stability. The recently proposed Lagrangian Frame Two-Plasmon Decay mode (LFTPD) is investigated in the regime in which the instability is not resonantly coupled to surface waves propagating along the boundary region. In this case they have found both spatially dependent growth rate profiles and spatially dependent transit layer magnetic fields due to nonlinear surface currents. LFTPD growth rate profiles are displayed as a function of pump amplitude. The results of a time domain simulation of this mode is also shown

Current generation by monochromatic electromagnetic waves

International Nuclear Information System (INIS)

Belikov, V.S.; Kolesnichenko, Ya.I.; Plotnik, I.S.

1983-01-01

The generation of longitudinal currents in a magnetically confined plasma with travelling monochromatic electromagnetic waves of finite amplitude propagating at some angle to the external magnetic field is considered. By averaging over the particle cyclotron gyration period, the kinetic equation for the distribution function of electrons interacting with an electromagnetic wave is derived. This equation is solved for the case of low-frequency waves, on the assumption that the bounce period of electrons trapped by the wave field is small compared to the typical times of Coulomb collisions (in which case, the driving current is largest). From the solution obtained, analytic expressions for the driving current and the absorbed power, which are valid for a wide range of wave phase velocities, are found. The current drive method considered and the method using the wave packet are compared. (author)

Alteration in murine epidermal Langerhans cell population by various UV irradiations: quantitative and morphologic studies on the effects of various wavelengths of monochromatic radiation on Ia-bearing cells

International Nuclear Information System (INIS)

Obata, M.; Tagami, H.

1985-01-01

The present study was undertaken in order to clarify the exact mode of the Langerhans cell (LC) depleting process caused by UV irradiation. Following irradiation with a single dose of various wavelengths of monochromatic UV radiation (UVR), the number of Ia-positive cells were studied in mouse epidermal sheets quantitatively, particularly with regard to dose-response relationships, action spectrum, and time course change. In addition, morphologic alterations of these cells were studied using electron- and immunoelectron microscopy (EM and IEM). The authors obtained the following results after a single dose of UVB radiation (200 mJ/cm2 of 300 nm) or PUVA (1% of 8-methoxypsoralen (8-MOP) 20 microliter and 1 J/cm2 of 360 nm): (1) EM and IEM showed that while some LCs simply lost their Ia marker without any structural alterations, the majority of the LCs disappeared due to actual cell damage. (2) During an ''injury phase,'' the initial 48 h, and a ''recovery phase,'' lasting from 4-14 days after irradiation, enlargement of the size of remaining Ia-positive LCs occurred. The degree of enlargement was closely related to the degree of reduction in number, suggesting a process compensating for the loss of the LC population. (3) It was found that the recovery rate of LCs after irradiation damage was slower than that of keratinocytes, indicating different cell kinetics between these distinct cell populations in the epidermis, i.e., restoration of LCs after irradiation seems to be achieved at least partially through a repopulation process originating in the bone marrow

A Study of Radiation Incidence Angle in Anteroposterior Cervical Vertebra Examination

International Nuclear Information System (INIS)

Jeung, Seung Woon; Lim, Cheong Hwan; Jung, Hong Ryang; Joo, Yeong Cheol; Park, Mi Ja; Han, Beon Hee

2012-01-01

cervical vertebra, OID, axis angle, and FID, all of them were shown to have correlations with the incidence angle (p<.01). Conclusively, it was shown that the incidence angle was measured differently from average length of cervical vertebra, OID, FID, and axis slope, as well as from age and sex. Therefore, it can be suggested that the anteroposterior radiation test for cervical vertebra should be conducted by different incidence angles based on age and sex. The data of this study may be used as reference in determining the incidence angle of cervical vertebra tests for the future.

A Study of Radiation Incidence Angle in Anteroposterior Cervical Vertebra Examination

Energy Technology Data Exchange (ETDEWEB)

Jeung, Seung Woon; Lim, Cheong Hwan; Jung, Hong Ryang; Joo, Yeong Cheol; Park, Mi Ja [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of); Han, Beon Hee [Dept. of Radiological Science, Seonam University, Namwon (Korea, Republic of)

2012-06-15

of cervical vertebra, OID, axis angle, and FID, all of them were shown to have correlations with the incidence angle (p<.01). Conclusively, it was shown that the incidence angle was measured differently from average length of cervical vertebra, OID, FID, and axis slope, as well as from age and sex. Therefore, it can be suggested that the anteroposterior radiation test for cervical vertebra should be conducted by different incidence angles based on age and sex. The data of this study may be used as reference in determining the incidence angle of cervical vertebra tests for the future.

Adverse radiation effect after stereotactic radiosurgery for brain metastases : incidence, time course, and risk factors

NARCIS (Netherlands)

Sneed, Penny K.; Mendez, Joe; Vemer-van den Hoek, Johanna; Seymour, Zachary A.; Ma, Lijun; Molinaro, Annette M.; Fogh, Shannon E.; Nakamura, Jean L.; McDermott, Michael W.

OBJECT The authors sought to determine the incidence, time course, and risk factors for overall adverse radiation effect (ARE) and symptomatic ARE after stereotactic radiosurgery (SRS) for brain metastases. METHODS All cases of brain metastases treated from 1998 through 2009 with Gamma Knife SRS at

Energy-angle correlation correction algorithm for monochromatic computed tomography based on Thomson scattering X-ray source

Science.gov (United States)

Chi, Zhijun; Du, Yingchao; Huang, Wenhui; Tang, Chuanxiang

2017-12-01

The necessity for compact and relatively low cost x-ray sources with monochromaticity, continuous tunability of x-ray energy, high spatial coherence, straightforward polarization control, and high brightness has led to the rapid development of Thomson scattering x-ray sources. To meet the requirement of in-situ monochromatic computed tomography (CT) for large-scale and/or high-attenuation materials based on this type of x-ray source, there is an increasing demand for effective algorithms to correct the energy-angle correlation. In this paper, we take advantage of the parametrization of the x-ray attenuation coefficient to resolve this problem. The linear attenuation coefficient of a material can be decomposed into a linear combination of the energy-dependent photoelectric and Compton cross-sections in the keV energy regime without K-edge discontinuities, and the line integrals of the decomposition coefficients of the above two parts can be determined by performing two spectrally different measurements. After that, the line integral of the linear attenuation coefficient of an imaging object at a certain interested energy can be derived through the above parametrization formula, and monochromatic CT can be reconstructed at this energy using traditional reconstruction methods, e.g., filtered back projection or algebraic reconstruction technique. Not only can monochromatic CT be realized, but also the distributions of the effective atomic number and electron density of the imaging object can be retrieved at the expense of dual-energy CT scan. Simulation results validate our proposal and will be shown in this paper. Our results will further expand the scope of application for Thomson scattering x-ray sources.

A management plan for hospitals and medical centers facing radiation incidents

Directory of Open Access Journals (Sweden)

Fereshteh Davari

2015-01-01

Full Text Available Background: Nowadays, application of nuclear technology in different industries has largely expanded worldwide. Proportionately, the risk of nuclear incidents and the resulting injuries have, therefore, increased in recent years. Preparedness is an important part of the crisis management cycle; therefore efficient preplanning seems crucial to any crisis management plan. Equipped with facilities and experienced personnel, hospitals naturally engage with the response to disasters. The main purpose of our study was to present a practical management pattern for hospitals and medical centers in case they encounter a nuclear emergency. Materials and Methods: In this descriptive qualitative study, data were collected through experimental observations, sources like Safety manuals released by the International Atomic Energy Agency and interviews with experts to gather their ideas along with Delphi method for polling, and brainstorming. In addition, the 45 experts were interviewed on three targeted using brainstorming and Delphi method. Results: We finally proposed a management plan along with a set of practicality standards for hospitals and medical centers to optimally respond to nuclear medical emergencies when a radiation incident happens nearby. Conclusion: With respect to the great importance of preparedness against nuclear incidents adoption and regular practice of nuclear crisis management codes for hospitals and medical centers seems quite necessary.

Infant brain tumors: incidence, survival, and the role of radiation based on Surveillance, Epidemiology, and End Results (SEER) Data.

Science.gov (United States)

Bishop, Andrew J; McDonald, Mark W; Chang, Andrew L; Esiashvili, Natia

2012-01-01

To evaluate the incidence of infant brain tumors and survival outcomes by disease and treatment variables. The Surveillance, Epidemiology, and End Results (SEER) Program November 2008 submission database provided age-adjusted incidence rates and individual case information for primary brain tumors diagnosed between 1973 and 2006 in infants less than 12 months of age. Between 1973 and 1986, the incidence of infant brain tumors increased from 16 to 40 cases per million (CPM), and from 1986 to 2006, the annual incidence rate averaged 35 CPM. Leading histologies by annual incidence in CPM were gliomas (13.8), medulloblastoma and primitive neuroectodermal tumors (6.6), and ependymomas (3.6). The annual incidence was higher in whites than in blacks (35.0 vs. 21.3 CPM). Infants with low-grade gliomas had the highest observed survival, and those with atypical teratoid rhabdoid tumors (ATRTs) or primary rhabdoid tumors of the brain had the lowest. Between 1979 and 1993, the annual rate of cases treated with radiation within the first 4 months from diagnosis declined from 20.5 CPM to incidence of infant brain tumors has been stable since 1986. Survival outcomes varied markedly by histology. For infants with medulloblastoma and ATRTs, improved survival was observed in patients treated with both surgery and early radiation compared with those treated with surgery alone. Copyright © 2012 Elsevier Inc. All rights reserved.

A compact soft x-ray (0.1–1.2 keV) calibration bench for radiometric measurements using an original versatile Rowland circle grazing incidence monochromator

Energy Technology Data Exchange (ETDEWEB)

Hubert, S., E-mail: sebastien.hubert@cea.fr

2017-05-21

This paper describes an original Rowland circle grazing incidence spectrometer used as a monochromator for a soft x-ray Manson source in order to calibrate both the source and detectors over the 0.1–1.2 keV spectral range. The originality of the instrument lies on a patented vacuum manipulator which allows the simultaneous boarding of two detectors, one (reference) for measuring the monochromatic radiation and the second to be calibrated. In order to achieve this, the vacuum manipulator is able to interchange, in vacuum, one detector with the other in front of the exit slit of the monochromatizing stage. One purpose of this apparatus was to completely eliminate the intrinsic bremsstrahlung emission of the x-ray diode source and isolate each characteristic line for quantitative detector calibrations. Obtained spectral resolution (Δλ/λ<10{sup −2}) and spectral purity (>98%) fully meet this objective. Initially dimensioned to perform calibration of bulky x-ray cameras unfolded on the Laser MégaJoule Facility, other kinds of detector can be obviously calibrated using this instrument. A brief presentation of the first calibration of an x-ray CCD through its quantum efficiency (QE) measurement is included in this paper as example. Comparison with theoretical model for QE and previous measurements at higher energy are finally presented and discussed.

A pulsed neutron monochromatic beam at the ET-RR-1 reactor

International Nuclear Information System (INIS)

Adib, M.; Abdel-Kawy, A.; Eid, Y.; Maayouf, R.M.A.

1985-01-01

A pulsed neutron monochromatic beam, at the ET-RR-1 reactor, is produced by two 32 cm diameter rotors suspended in magnetic fields, whose centres are 126 cm apart rotating at speeds up to 16,000 rev/min. Each of the rotors has two slots, which are of constant cross-section in area - 7x10mm 2 , and are curved so that they have a maximum transmission for neutrons whose speed is 8.2 times that of the rotor tip. The jitter of the phase between the rotors at different rotation rates is found not to exceed +-1 μs. It has been found that both the observed time distribution and the TOF distribution of the neutrons at different rotation rates are in good agreement with the calculated ones. The observed intensity of the monochromatic neutrons of wavelength 2.74+-0.09 A, obtained by the rotors rotating at a speed of 10,500 rev/min with 864+-1 μs difference in phase between them, is 66.8 n/s. This value is found to be less than the predicted one by a factor of 5.5. (author)

Coherence properties of blackbody radiation and application to energy harvesting and imaging with nanoscale rectennas

Science.gov (United States)

Lerner, Peter B.; Cutler, Paul H.; Miskovsky, Nicholas M.

2015-01-01

Modern technology allows the fabrication of antennas with a characteristic size comparable to the electromagnetic wavelength in the optical region. This has led to the development of new technologies using nanoscale rectifying antennas (rectennas) for solar energy conversion and sensing of terahertz, infrared, and visible radiation. For example, a rectenna array can collect incident radiation from an emitting source and the resulting conversion efficiency and operating characteristics of the device will depend on the spatial and temporal coherence properties of the absorbed radiation. For solar radiation, the intercepted radiation by a micro- or nanoscale array of devices has a relatively narrow spatial and angular distribution. Using the Van Cittert-Zernike theorem, we show that the coherence length (or radius) of solar radiation on an antenna array is, or can be, tens of times larger than the characteristic wavelength of the solar spectrum, i.e., the thermal wavelength, λT=2πℏc/(kBT), which for T=5000 K is about 3 μm. Such an effect is advantageous, making possible the rectification of solar radiation with nanoscale rectenna arrays, whose size is commensurate with the coherence length. Furthermore, we examine the blackbody radiation emitted from an array of antennas at temperature T, which can be quasicoherent and lead to a modified self-image, analogous to the Talbot-Lau self-imaging process but with thermal rather than monochromatic radiation. The self-emitted thermal radiation may be important as a nondestructive means for quality control of the array.

Superradiance or total reflection?

CERN Document Server

László, András

2014-01-01

Numerical evolution of massless scalar fields on Kerr background is studied. The initial data specifications are chosen to have compact support separated from the ergoregion and to yield nearly monochromatic incident wave packets. The initial data is also tuned to maximize the effect of superradiance. Evidences are shown indicating that instead of the anticipated energy extraction from black hole the incident radiation fail to reach the ergoregion rather it suffers a nearly perfect reflection.

Composites with carbon nanotube for radiation shielding application

International Nuclear Information System (INIS)

Fontainha, Críssia C.P.; Nunes, Modesto; Rosas, Víctor A.

2017-01-01

Polymeric composites filled with attenuating metals and functionalized with carbon nanotubes (NTC) are being largely developed. New attenuators materials have been widely investigated for radiation shielding to apply in procedures as interventional radiology, Computed Tomography (CT) and nuclear medicine. In this work composites for radiation attenuation in radiodiagnostic imaging procedures made of inorganic material as filler, by a sol-gel method, in poly(vinylidene fluoride-tryfluorethylene) [P(VDF-TrFE] copolymers that are used as the polymeric matrix. Two different metal attenuators were used as fillers: zirconia stabilized by yttria (8% wt.) and bismuth oxide. Carbon nanotubes were added with different concentrations at the solution of attenuator metal under controlled magnetic stirring. Characterization of composites by FTIR, UV-Vis, DSC and SEM-EDS were carried out. In a previous analysis of radiation attenuation, was used an incident monochromatic X-ray beam from the RIGAKU diffractometer. In this setup, one reference measure is directly exposed to the x-rays being diffracted by single crystal of Si (111). Another measure the attenuated beam is performed with the composite sample under detector. The functionalization of the carbon nanotube of multiple walls (MWNCT) in the in the P(VDF-TrFE) was evaluated. The samples present a good dispersion of the attenuator metal into presence at methacrylic acid. The cheap tube presented better dispersion in the polymer matrix than the 3100 nanotubes. Bismuth oxidation composites showed a better attenuation factor compared to Zirconia stabilized by yttria composites. (author)

Composites with carbon nanotube for radiation shielding application

Energy Technology Data Exchange (ETDEWEB)

Fontainha, Críssia C.P.; Nunes, Modesto; Rosas, Víctor A., E-mail: crissia@gmail.com [Universidade Federal de Minas Gerais (IMA/UFMG), Belo Horizonte, MG (Brazil). Dept. de Anatomia e Imagem; Santos, Adelina P.; Furtado, Clascídia A.; Faria, Luiz O., E-mail: farialo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Polymeric composites filled with attenuating metals and functionalized with carbon nanotubes (NTC) are being largely developed. New attenuators materials have been widely investigated for radiation shielding to apply in procedures as interventional radiology, Computed Tomography (CT) and nuclear medicine. In this work composites for radiation attenuation in radiodiagnostic imaging procedures made of inorganic material as filler, by a sol-gel method, in poly(vinylidene fluoride-tryfluorethylene) [P(VDF-TrFE] copolymers that are used as the polymeric matrix. Two different metal attenuators were used as fillers: zirconia stabilized by yttria (8% wt.) and bismuth oxide. Carbon nanotubes were added with different concentrations at the solution of attenuator metal under controlled magnetic stirring. Characterization of composites by FTIR, UV-Vis, DSC and SEM-EDS were carried out. In a previous analysis of radiation attenuation, was used an incident monochromatic X-ray beam from the RIGAKU diffractometer. In this setup, one reference measure is directly exposed to the x-rays being diffracted by single crystal of Si (111). Another measure the attenuated beam is performed with the composite sample under detector. The functionalization of the carbon nanotube of multiple walls (MWNCT) in the in the P(VDF-TrFE) was evaluated. The samples present a good dispersion of the attenuator metal into presence at methacrylic acid. The cheap tube presented better dispersion in the polymer matrix than the 3100 nanotubes. Bismuth oxidation composites showed a better attenuation factor compared to Zirconia stabilized by yttria composites. (author)

Spatial variation of natural radiation and childhood leukaemia incidence in Great Britain

International Nuclear Information System (INIS)

Richardson, Sylvia; Monfort, Christine; Green, Martyn; Muirhead, Colin; Draper, Gerald

1995-01-01

This paper describes an analysis of the geographical variation of childhood leukaemia incidence in Great Britain over a 15 year period in relation to natural radiation (gamma and radon). Data at the level of the 459 district level local authorities in England, Wales and regional districts in Scotland are analysed in two complementary ways: first, by Poisson regressions with the inclusion of environmental covariates and a smooth spatial structure; secondly, by a hierarchical Bayesian model in which extra-Poisson variability is modelled explicitly in terms of spatial and non-spatial components. From this analysis, we deduce a strong indication that a main part of the variability is accounted for by a local neighbourhood 'clustering' structure. This structure is furthermore relatively stable over the 15 year period for the lymphocytic leukaemias which make up the majority of observed cases. We found no evidence of a positive association of childhood leukaemia incidence with outdoor or indoor gamma radiation levels. There is no consistent evidence of any association with radon levels. Indeed, in the Poisson regressions, a significant positive association was only observed for one 5-year period, a result which is not compatible with a stable environmental effect. Moreover, this positive association became clearly non-significant when over-dispersion relative to the Poisson distribution was taken into account. (author)

Theoretical study of the thermal radiation of rough surfaces. Development of a device for the measurement of emissivity, and application to AISI 316 stainless steel

International Nuclear Information System (INIS)

Heinisch, Bruno

1982-01-01

Within the frame of the study of heat transfers by radiation, this research thesis addresses the theoretical and experimental determination of the directional monochromatic emissivity. After some theoretical recalls, the author presents models for a direct calculation of emissivity, which in fact calculate bidirectional reflectivity by using laws of physical optics. An experimental device has been developed for the direct measurement of directional monochromatic emissivity of materials in the infrared (wavelength from 2 to 15 microns) in a polarised radiation. This device uses double beam with double modulation. Experimental results are presented for the 316 stainless steel [fr

Frequency-locked pulse sequencer for high-frame-rate monochromatic tissue motion imaging.

Science.gov (United States)

Azar, Reza Zahiri; Baghani, Ali; Salcudean, Septimiu E; Rohling, Robert

2011-04-01

To overcome the inherent low frame rate of conventional ultrasound, we have previously presented a system that can be implemented on conventional ultrasound scanners for high-frame-rate imaging of monochromatic tissue motion. The system employs a sector subdivision technique in the sequencer to increase the acquisition rate. To eliminate the delays introduced during data acquisition, a motion phase correction algorithm has also been introduced to create in-phase displacement images. Previous experimental results from tissue- mimicking phantoms showed that the system can achieve effective frame rates of up to a few kilohertz on conventional ultrasound systems. In this short communication, we present a new pulse sequencing strategy that facilitates high-frame-rate imaging of monochromatic motion such that the acquired echo signals are inherently in-phase. The sequencer uses the knowledge of the excitation frequency to synchronize the acquisition of the entire imaging plane to that of an external exciter. This sequencing approach eliminates any need for synchronization or phase correction and has applications in tissue elastography, which we demonstrate with tissue-mimicking phantoms. © 2011 IEEE

Incidence and predictors of Lhermitte’s sign among patients receiving mediastinal radiation for lymphoma

International Nuclear Information System (INIS)

Youssef, Bassem; Shank, JoAnn; Reddy, Jay P.; Pinnix, Chelsea C.; Farha, George; Akhtari, Mani; Allen, Pamela K.; Fanale, Michelle A.; Garcia, John A.; Horace, Patricia H.; Milgrom, Sarah; Smith, Grace Li; Nieto, Yago; Arzu, Isadora; Wang, He; Fowler, Nathan; Rodriguez, Maria Alma; Dabaja, Bouthaina

2015-01-01

To prospectively examine the risk of developing Lhermitte’s sign (LS) in patients with lymphoma treated with modern-era chemotherapy followed by consolidation intensity-modulated radiation therapy. We prospectively interviewed all patients with lymphoma who received irradiation to the mediastinum from July 2011 through April 2014. We extracted patient, disease, and treatment-related variables from the medical records of those patients and dosimetric variables from treatment-planning systems and analyzed these factors to identify potential predictors of LS with Pearson chi-square tests. During the study period 106 patients received mediastinal radiation for lymphoma, and 31 (29 %) developed LS. No correlations were found between LS and any of the variables examined, including total radiation dose, maximum point dose to the spinal cord, volume receiving 105 % of the dose, and volumes receiving 5 or 15 Gy. In this group of patients, treatment with chemotherapy followed by intensity-modulated radiation therapy led to 29 % developing LS; this symptom was independent of radiation dose and seemed to be an idiosyncratic reaction. This relatively high incidence could have resulted from prospective use of a structured interview

Concept of quasi-periodic undulator - control of radiation spectrum

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Shigemi [Japan Atomic Energy Research Institute, Ibaraki (Japan)

1995-02-01

A new type of undulator, the quasi-periodic undulator (QPU) is considered which generates the irrational harmonics in the radiation spectrum. This undulator consists of the arrays of magnet blocks aligned in a quasi-periodic order, and consequentially lead to a quasi-periodic motion of electron. A combination of the QPU and a conventional crystal/grating monochromator provides pure monochromatic photon beam for synchrotron radiation users because the irrational harmonics do not be diffracted in the same direction by a monochromator. The radiation power and width of each radiation peak emitted from this undulator are expected to be comparable with those of the conventional periodic undulator.

Detection of fissionable materials in cargoes using monochromatic photon radiography

Science.gov (United States)

Danagoulian, Areg; Lanza, Richard; O'Day, Buckley; LNSP Team

2015-04-01

The detection of Special Nuclear Materials (e.g. Pu and U) and nuclear devices in the commercial cargo traffic is one of the challenges posed by the threat of nuclear terrorism. Radiography and active interrogation of heavily loaded cargoes require ~ 1 - 10MeV photons for penetration. In a proof-of-concept system under development at MIT, the interrogating monochromatic photon beam is produced via a 11B(d , nγ) 12C reaction. To achieve this, a boron target is used along with the 3 MeV d+ RFQ accelerator at MIT-Bates. The reactions results in the emission of very narrow 4.4 MeV and 15.1 MeV gammas lines. The photons, after traversing the cargo, are detected by an array of NaI(Tl) detectors. A spectral analysis of the transmitted gammas allows to independently determine the areal density and the atomic number (Z) of the cargo. The proposed approach could revolutionize cargo inspection, which, in its current fielded form has to rely on simple but high dose bremsstrahlung sources. Use of monochromatic sources would significantly reduce the necessary dose and allow for better determination of the cargo's atomic number. The general methodology will be described and the preliminary results from the proof-of-concept system will be presented and discussed. Supported by NSF/DNDO Collaborative Research ARI-LA Award ECCS-1348328.

Monochromatic Minibeams Radiotherapy: From Healthy Tissue-Sparing Effect Studies Toward First Experimental Glioma Bearing Rats Therapy

Energy Technology Data Exchange (ETDEWEB)

Deman, Pierre [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Vautrin, Mathias [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); DOSIsoft, Cachan (France); Edouard, Magali [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Stupar, Vasile [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); Bobyk, Laure; Farion, Regine [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Elleaume, Helene [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Grenoble University Hospital, Grenoble (France); Remy, Chantal; Barbier, Emmanuel L. [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); Esteve, Francois [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Grenoble University Hospital, Grenoble (France); Adam, Jean-Francois, E-mail: adam@esrf.fr [INSERM, Grenoble (France); Universite Joseph Fourier, Institut des Neurosciences, Grenoble (France); European Synchrotron Radiation Facility, Grenoble (France); Grenoble University Hospital, Grenoble (France)

2012-03-15

Purpose: The purpose of this study was to evaluate high-dose single fraction delivered with monochromatic X-rays minibeams for the radiotherapy of primary brain tumors in rats. Methods and Materials: Two groups of healthy rats were irradiated with one anteroposterior minibeam incidence (four minibeams, 123 Gy prescribed dose at 1 cm depth in the brain) or two interleaved incidences (54 Gy prescribed dose in a 5 Multiplication-Sign 5 Multiplication-Sign 4.8 mm{sup 3} volume centered in the right hemisphere), respectively. Magnetic resonance imaging (MRI) follow-up was performed over 1 year. T2-weighted (T2w) images, apparent diffusion coefficient (ADC), and blood vessel permeability maps were acquired. F98 tumor bearing rats were also irradiated with interleaved minibeams to achieve a homogeneous dose of 54 Gy delivered to an 8 Multiplication-Sign 8 Multiplication-Sign 7.8 mm{sup 3} volume centered on the tumor. Anatomic and functional MRI follow-up was performed every 10 days after irradiation. T2w images, ADC, and perfusion maps were acquired. Results: All healthy rats were euthanized 1 year after irradiation without any clinical alteration visible by simple examination. T2w and ADC measurements remain stable for the single incidence irradiation group. Localized Gd-DOTA permeability, however, was observed 9 months after irradiation for the interleaved incidences group. The survival time of irradiated glioma bearing rats was significantly longer than that of untreated animals (49 {+-} 12.5 days versus 23.3 {+-} 2 days, p < 0.001). The tumoral cerebral blood flow and blood volume tend to decrease after irradiation. Conclusions: This study demonstrates the sparing effect of minibeams on healthy tissue. The increased life span achieved for irradiated glioma bearing rats was similar to the one obtained with other radiotherapy techniques. This experimental tumor therapy study shows the feasibility of using X-ray minibeams with high doses in brain tumor radiotherapy.

SU-D-BRA-06: Dual-Energy Chest CT: The Effects of Virtual Monochromatic Reconstructions On Texture Analysis Features

International Nuclear Information System (INIS)

Sorensen, J; Duran, C; Stingo, F; Wei, W; Rao, A; Zhang, L; Court, L; Erasmus, J; Godoy, M

2015-01-01

Purpose: To characterize the effect of virtual monochromatic reconstructions on several commonly used texture analysis features in DECT of the chest. Further, to assess the effect of monochromatic energy levels on the ability of these textural features to identify tissue types. Methods: 20 consecutive patients underwent chest CTs for evaluation of lung nodules using Siemens Somatom Definition Flash DECT. Virtual monochromatic images were constructed at 10keV intervals from 40–190keV. For each patient, an ROI delineated the lesion under investigation, and cylindrical ROI’s were placed within 5 different healthy tissues (blood, fat, muscle, lung, and liver). Several histogram- and Grey Level Cooccurrence Matrix (GLCM)-based texture features were then evaluated in each ROI at each energy level. As a means of validation, these feature values were then used in a random forest classifier to attempt to identify the tissue types present within each ROI. Their predictive accuracy at each energy level was recorded. Results: All textural features changed considerably with virtual monochromatic energy, particularly below 70keV. Most features exhibited a global minimum or maximum around 80keV, and while feature values changed with energy above this, patient ranking was generally unaffected. As expected, blood demonstrated the lowest inter-patient variability, for all features, while lung lesions (encompassing many different pathologies) exhibited the highest. The accuracy of these features in identifying tissues (76% accuracy) was highest at 80keV, but no clear relationship between energy and classification accuracy was found. Two common misclassifications (blood vs liver and muscle vs fat) accounted for the majority (24 of the 28) errors observed. Conclusion: All textural features were highly dependent on virtual monochromatic energy level, especially below 80keV, and were more stable above this energy. However, in a random forest model, these commonly used features were

SU-D-BRA-06: Dual-Energy Chest CT: The Effects of Virtual Monochromatic Reconstructions On Texture Analysis Features

Energy Technology Data Exchange (ETDEWEB)

Sorensen, J; Duran, C; Stingo, F; Wei, W; Rao, A; Zhang, L; Court, L; Erasmus, J; Godoy, M [UT MD Anderson Cancer Center, Houston, TX (United States)

2015-06-15

Purpose: To characterize the effect of virtual monochromatic reconstructions on several commonly used texture analysis features in DECT of the chest. Further, to assess the effect of monochromatic energy levels on the ability of these textural features to identify tissue types. Methods: 20 consecutive patients underwent chest CTs for evaluation of lung nodules using Siemens Somatom Definition Flash DECT. Virtual monochromatic images were constructed at 10keV intervals from 40–190keV. For each patient, an ROI delineated the lesion under investigation, and cylindrical ROI’s were placed within 5 different healthy tissues (blood, fat, muscle, lung, and liver). Several histogram- and Grey Level Cooccurrence Matrix (GLCM)-based texture features were then evaluated in each ROI at each energy level. As a means of validation, these feature values were then used in a random forest classifier to attempt to identify the tissue types present within each ROI. Their predictive accuracy at each energy level was recorded. Results: All textural features changed considerably with virtual monochromatic energy, particularly below 70keV. Most features exhibited a global minimum or maximum around 80keV, and while feature values changed with energy above this, patient ranking was generally unaffected. As expected, blood demonstrated the lowest inter-patient variability, for all features, while lung lesions (encompassing many different pathologies) exhibited the highest. The accuracy of these features in identifying tissues (76% accuracy) was highest at 80keV, but no clear relationship between energy and classification accuracy was found. Two common misclassifications (blood vs liver and muscle vs fat) accounted for the majority (24 of the 28) errors observed. Conclusion: All textural features were highly dependent on virtual monochromatic energy level, especially below 80keV, and were more stable above this energy. However, in a random forest model, these commonly used features were

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-07-01

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

Electromagnetically Induced Transparency and Absorption of A Monochromatic Light Controlled by a Radio Frequency Field

International Nuclear Information System (INIS)

Cai Xun-Ming

2015-01-01

Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are coupled by a radio frequency (RF) field. Both electromagnetically induced transparency and electromagnetically induced absorption can be obtained by tuning the frequency of RF field for both the linear polarization and elliptical polarization monochromatic lights. When the transfer of coherence via spontaneous emission from the excited state to the ground state is considered, electromagnetically induced absorption can be changed into electromagnetically induced transparency with the change of intensity of radio field. The transparency windows controlled by the RF field can have potential applications in the magnetic-field measurement and quantum information processing. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Assessment of ionizing radiation as a risk factor for breast cancer incidence in Goiania

International Nuclear Information System (INIS)

Lage, Leonardo Bastos

2016-01-01

This research aims to evaluate whether exposure to ionizing radiation to which women are subjected can be associated with the incidence of breast cancer in Goiania. The defined study area is the central region of Goiania, or the Sanitary Districts of Campinas-Centro and Sul, in which are the seven major accident sources of contamination with Cesium 137, and also, as shown by previous study, the majority of new cases of breast cancer (60,43 %). We used the geographical division of the city in census tracts and health districts. The data collection was divided in two stages: the first, for the survey of radiometric measurements, and the second, for identifying the addresses of women diagnosed with breast cancer. The radiometric survey occurred between 2010 and 2014, in which was used an environmental gamma radiation mobile measuring system. This system was composed by a high-sensitivity detector coupled to a Global Positioning System (GPS) and a microcomputer. The assembly was installed on a motor vehicle so that the height of the detector is found at one meter from the ground, and programmed to obtain a measurement of the doses absorbed in the air rate each second. The data collected were: doses absorbed in the air rate, geographical coordinates, altitude, date and time of acquisition. From Mobisys software, files were generated and from ArcGIS 10.0 platform, geospatial assessment survey through the elaboration of thematic maps and geospatial analysis statistics. The annual averages of effective doses and collective effective doses were estimated from the rate of doses absorbed in air collected by the system and the resident population in the census tracts. The second stage begun from the data collection at the Registry of Goiania's Population Based Cancer (RCBPGO), in which were identified addresses of women diagnosed with breast cancer between 2001 and 2010. Part of the data was geographically referenced and using census data were estimated and compared the

An Evaluation of Departmental Radiation Oncology Incident Reports: Anticipating a National Reporting System

Energy Technology Data Exchange (ETDEWEB)

Terezakis, Stephanie A., E-mail: stereza1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Harris, Kendra M. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Ford, Eric [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Michalski, Jeff [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); DeWeese, Theodore [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Santanam, Lakshmi; Mutic, Sasa; Gay, Hiram [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)

2013-03-15

Purpose: Systems to ensure patient safety are of critical importance. The electronic incident reporting systems (IRS) of 2 large academic radiation oncology departments were evaluated for events that may be suitable for submission to a national reporting system (NRS). Methods and Materials: All events recorded in the combined IRS were evaluated from 2007 through 2010. Incidents were graded for potential severity using the validated French Nuclear Safety Authority (ASN) 5-point scale. These incidents were categorized into 7 groups: (1) human error, (2) software error, (3) hardware error, (4) error in communication between 2 humans, (5) error at the human-software interface, (6) error at the software-hardware interface, and (7) error at the human-hardware interface. Results: Between the 2 systems, 4407 incidents were reported. Of these events, 1507 (34%) were considered to have the potential for clinical consequences. Of these 1507 events, 149 (10%) were rated as having a potential severity of ≥2. Of these 149 events, the committee determined that 79 (53%) of these events would be submittable to a NRS of which the majority was related to human error or to the human-software interface. Conclusions: A significant number of incidents were identified in this analysis. The majority of events in this study were related to human error and to the human-software interface, further supporting the need for a NRS to facilitate field-wide learning and system improvement.

An Evaluation of Departmental Radiation Oncology Incident Reports: Anticipating a National Reporting System

International Nuclear Information System (INIS)

Terezakis, Stephanie A.; Harris, Kendra M.; Ford, Eric; Michalski, Jeff; DeWeese, Theodore; Santanam, Lakshmi; Mutic, Sasa; Gay, Hiram

2013-01-01

Purpose: Systems to ensure patient safety are of critical importance. The electronic incident reporting systems (IRS) of 2 large academic radiation oncology departments were evaluated for events that may be suitable for submission to a national reporting system (NRS). Methods and Materials: All events recorded in the combined IRS were evaluated from 2007 through 2010. Incidents were graded for potential severity using the validated French Nuclear Safety Authority (ASN) 5-point scale. These incidents were categorized into 7 groups: (1) human error, (2) software error, (3) hardware error, (4) error in communication between 2 humans, (5) error at the human-software interface, (6) error at the software-hardware interface, and (7) error at the human-hardware interface. Results: Between the 2 systems, 4407 incidents were reported. Of these events, 1507 (34%) were considered to have the potential for clinical consequences. Of these 1507 events, 149 (10%) were rated as having a potential severity of ≥2. Of these 149 events, the committee determined that 79 (53%) of these events would be submittable to a NRS of which the majority was related to human error or to the human-software interface. Conclusions: A significant number of incidents were identified in this analysis. The majority of events in this study were related to human error and to the human-software interface, further supporting the need for a NRS to facilitate field-wide learning and system improvement

Theory of the special Smith-Purcell radiation from a rectangular grating

Energy Technology Data Exchange (ETDEWEB)

Liu, Weihao, E-mail: liuwhao@ustc.edu.cn; He, Zhigang, E-mail: hezhg@ustc.edu.cn; Jia, Qika [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029 (China); Li, Weiwei [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029 (China); Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, via E. Fermi 40, 00044 Frascati, RM (Italy)

2015-12-15

The recently uncovered special Smith-Purcell radiation (S-SPR) from the rectangular grating has significantly higher intensity than the ordinary Smith-Purcell radiation (SPR). Its monochromaticity and directivity are also much better. Here we explored the mechanism of the S-SPR by applying the fundamental electromagnetic theory and simulations. We have confirmed that the S-SPR is exactly from the radiating eigen modes of the grating. Its frequency and direction are well correlated with the beam velocity and structure parameters, which indicates its promising applications in tunable wave generation and beam diagnostic.

Theory of the special Smith-Purcell radiation from a rectangular grating

International Nuclear Information System (INIS)

Liu, Weihao; He, Zhigang; Jia, Qika; Li, Weiwei

2015-01-01

The recently uncovered special Smith-Purcell radiation (S-SPR) from the rectangular grating has significantly higher intensity than the ordinary Smith-Purcell radiation (SPR). Its monochromaticity and directivity are also much better. Here we explored the mechanism of the S-SPR by applying the fundamental electromagnetic theory and simulations. We have confirmed that the S-SPR is exactly from the radiating eigen modes of the grating. Its frequency and direction are well correlated with the beam velocity and structure parameters, which indicates its promising applications in tunable wave generation and beam diagnostic

Radiation risk factors in incidence anortality among exposed individuals of East Kazakhstand m

Directory of Open Access Journals (Sweden)

Kazbek Apsalikov

2014-01-01

Full Text Available Introduction: Lengthy clinical and epidemiological studies at the Research Institute of Radiation Medicine and Ecology have discovered basic patterns of long-term effects from ionizing radiation in population groups exposed to radiation risk. Methodology for calculating injury from radiation risk factors has been developed and implemented to minimize the effects of the Semipalatinsk nuclear test site (SNTS. Material and methods: We analyzed materials from the database of the Scientific Medical Register that were exposed to radiation as a result of SNTS. We analyzed both male and female populations of the Abay, Beskaragai and Zhanasemei, Kokpekti (control areas of East-Kazakhstan region (EKR from 2008-2012. These populations were split into three groups allocated by the generation. The first group represented persons born from the period of 01/01/1930 -08/01/1949 and their children born from the period of 10/09/1949-12/31/1962. The second group were persons born after 01/01/1963. The third group served as the control and were persons who immigrated to these areas after 1990. Results: There was an increased incidence of cancer (21.5%, p < 0.000734, cardiovascular diseases (10.2%; respiratory problems (9.6%, gastrointestinal issues (9.1%, p < 0.00371-0.00679 in the first group. The effect of the radiation dose has not been fully stuided among the subjects in the second group.The major causes of excess mortality in the first group were neoplams (30.6%, hypertension (23.8%, and myocardial infarction (22.6%. The effects of radiation influenced mortality in the second group were 2-2.5 times lower than the first group.Conclusion: There is a correlation between the size of the radiation dose, the risk profile, and age at the moment of radiation exposure with trends of morbidity and mortality in the radiation exposed areas.

Advanced virtual monochromatic reconstruction of dual-energy unenhanced brain computed tomography in children: comparison of image quality against standard mono-energetic images and conventional polychromatic computed tomography

Energy Technology Data Exchange (ETDEWEB)

Park, Juil [Seoul National University Children' s Hospital, Department of Radiology, Seoul (Korea, Republic of); Choi, Young Hun [Seoul National University Children' s Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Cheon, Jung-Eun; Kim, Woo Sun; Kim, In-One [Seoul National University Children' s Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Pak, Seong Yong [Siemens Healthineers, Seoul (Korea, Republic of); Krauss, Bernhard [Siemens Healthineers, Forchheim (Germany)

2017-11-15

Advanced virtual monochromatic reconstruction from dual-energy brain CT has not been evaluated in children. To determine the most effective advanced virtual monochromatic imaging energy level for maximizing pediatric brain parenchymal image quality in dual-energy unenhanced brain CT and to compare this technique with conventional monochromatic reconstruction and polychromatic scanning. Using both conventional (Mono) and advanced monochromatic reconstruction (Mono+) techniques, we retrospectively reconstructed 13 virtual monochromatic imaging energy levels from 40 keV to 100 keV in 5-keV increments from dual-source, dual-energy unenhanced brain CT scans obtained in 23 children. We analyzed gray and white matter noise ratios, signal-to-noise ratios and contrast-to-noise ratio, and posterior fossa artifact. We chose the optimal mono-energetic levels and compared them with conventional CT. For Mono+maximum optima were observed at 60 keV, and minimum posterior fossa artifact at 70 keV. For Mono, optima were at 65-70 keV, with minimum posterior fossa artifact at 75 keV. Mono+ was superior to Mono and to polychromatic CT for image-quality measures. Subjective analysis rated Mono+superior to other image sets. Optimal virtual monochromatic imaging using Mono+ algorithm demonstrated better image quality for gray-white matter differentiation and reduction of the artifact in the posterior fossa. (orig.)

Photoelectron and Auger-electron spectra of Cl{sub 3}SiSi(CH{sub 3}){sub 3} obtained by using monochromatized synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Nagaoka, Shin-ichi, E-mail: nagaoka@ehime-u.ac.jp [Department of Chemistry, Faculty of Science and Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Endo, Hikaru; Nagai, Kanae [Department of Chemistry, Faculty of Science and Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Takahashi, Osamu [Institute for Sustainable Sciences and Development, Hiroshima University, Higashi-Hiroshima 739-8511 (Japan); Tamenori, Yusuke [Synchrotron Radiation Research Institute/SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun 679-5198 (Japan); Suzuki, Isao H. [Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan); Advanced Institute of Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba 305-8568 (Japan)

2014-08-15

Highlights: • Various photo- and Auger-electron spectra of Cl{sub 3}SiSi(CH{sub 3}){sub 3} vapor were measured. • The measured spectra were interpreted with the aid of some calculations. • The spectra showed profiles close to those expected from SiCl{sub 4} and Si(CH{sub 3}){sub 4}. • These results were discussed in conjunction with site-specific fragmentation. - Abstract: A variety of photoelectron and Auger-electron spectra of 1,1,1-trimethyltrichlorodisilane vapor (Cl{sub 3}SiSi(CH{sub 3}){sub 3}) were measured by using monochromatized synchrotron radiation and a hemispherical electron energy analyzer. The measured spectra were interpreted with the aid of some calculations by means of the outer valence Green's function (OVGF) method or the density-functional-theory (DFT) method. Since Cl{sub 3}SiSi(CH{sub 3}){sub 3} consists of -SiCl{sub 3} and -Si(CH{sub 3}){sub 3} moieties, the experimental core-electron binding-energies were compared with those of tetrachlorosilane and tetramethylsilane (SiCl{sub 4} and Si(CH{sub 3}){sub 4}, respectively). This comparison showed that electronic properties of Cl{sub 3}SiSi(CH{sub 3}){sub 3} hold a close correlation with those of SiCl{sub 4} and Si(CH{sub 3}){sub 4}. Si:L{sub 23}VV, Cl:L{sub 23}VV and C:KVV Auger-electron spectra of Cl{sub 3}SiSi(CH{sub 3}){sub 3} also showed profiles close to those expected from the spectra of SiCl{sub 4} and Si(CH{sub 3}){sub 4}. The results obtained here were discussed in conjunction with electronic relaxation leading to site-specific fragmentation.

Radiation effects in silicon and gallium arsenide solar cells using isotropic and normally incident radiation

Science.gov (United States)

Anspaugh, B. E.; Downing, R. G.

1984-01-01

Several types of silicon and gallium arsenide solar cells were irradiated with protons with energies between 50 keV and 10 MeV at both normal and isotropic incidence. Damage coefficients for maximum power relative to 10 MeV were derived for these cells for both cases of omni-directional and normal incidence. The damage coefficients for the silicon cells were found to be somewhat lower than those quoted in the Solar Cell Radiation Handbook. These values were used to compute omni-directional damage coefficients suitable for solar cells protected by coverglasses of practical thickness, which in turn were used to compute solar cell degradation in two proton-dominated orbits. In spite of the difference in the low energy proton damage coefficients, the difference between the handbook prediction and the prediction using the newly derived values was negligible. Damage coefficients for GaAs solar cells for short circuit current, open circuit voltage, and maximum power were also computed relative to 10 MeV protons. They were used to predict cell degradation in the same two orbits and in a 5600 nmi orbit. Results show the performance of the GaAs solar cells in these orbits to be superior to that of the Si cells.

Wavelength dispersive X-ray absorption fine structure imaging by parametric X-ray radiation

International Nuclear Information System (INIS)

Inagaki, Manabu; Sakai, Takeshi; Sato, Isamu; Hayakawa, Yasushi; Nogami, Kyoko; Tanaka, Toshinari; Hayakawa, Ken; Nakao, Keisuke

2008-01-01

The parametric X-ray radiation (PXR) generator system at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University is a monochromatic and coherent X-ray source with horizontal wavelength dispersion. The energy definition of the X-rays, which depends on the horizontal size of the incident electron beam on the generator target crystal, has been investigated experimentally by measuring the X-ray absorption near edge structure (XANES) spectra on Cu and CuO associated with conventional X-ray absorption imaging technique. The result demonstrated the controllability of the spectrum resolution of XANES by adjusting of the horizontal electron beam size on the target crystal. The XANES spectra were obtained with energy resolution of several eV at the narrowest case, which is in qualitative agreement with the energy definition of the PXR X-rays evaluated from geometrical consideration. The result also suggested that the wavelength dispersive X-ray absorption fine structure measurement associated with imaging technique is one of the promising applications of PXR. (author)

Incidence of primary hypothyroidism in patients exposed to therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland

Directory of Open Access Journals (Sweden)

B A Laway

2012-01-01

Full Text Available Introduction: Hypothyroidism is a known consequence of external-beam radiotherapy to the neck encompassing a part or whole of the thyroid gland. In this non-randomized prospective study, we have tried to evaluate the response of the thyroid gland to radiation by assessing thyroid function before irradiation and at regular intervals after irradiation. Aims and Objectives: The aim of this study were to assess in the cancer patients, who were exposed to the therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland: the incidence of primary hypothyroidism, the time required to become hypothyroid, any relation between the total dose for the development of hypothyroidism, and whether there are any patient or treatment-related factors that are predictive for the development of hypothyroidism, including the use of concurrent chemotherapy. Materials and Methods: This non-randomized, prospective study was conducted for a period of 2 years in which thyroid function was assessed in 59 patients (cases of head and neck cancer, breast cancer, lymphoma patients and other malignancies, who had received radiotherapy to the neck region. 59 euthyroid healthy patients (controls were also taken, who had not received the neck irradiation. These patients/controls were assessed periodically for 2 years. Results: The incidence of hypothyroidism after external beam radiation therapy (EBRT to neck where radiation portals include part or whole of the thyroid gland was 16.94%, seven cases had subclinical hypothyroidism (11.86% and three cases had clinical hypothyroidism (5.08%. Mean time for development of hypothyroidism was 4.5 months. There was no effect of age, gender, primary tumor site, radiation dose and chemotherapy, whether neoadjuvant or concurrent with the development of hypothyroidism. Conclusion: In summary, we found that thyroid dysfunction is a prevalent, yet easily treatable source of morbidity in patients

High-flux normal incidence monochromator for circularly polarized synchrotron radiation

International Nuclear Information System (INIS)

Schaefers, F.; Peatman, W.; Eyers, A.; Heckenkamp, C.; Schoenhense, G.; Heinzmann, U.

1986-01-01

A 6.5-m normal incidence monochromator installed at the storage ring BESSY, which is optimized for a high throughput of circularly polarized off-plane radiation at moderate resolution is described. The monochromator employs two exit slits and is specially designed and used for low-signal experiments such as spin- and angle-resolved photoelectron spectroscopy on solids, adsorbates, free atoms, and molecules. The Monk--Gillieson mounting (plane grating in a convergent light beam) allows for large apertures with relatively little astigmatism. With two gratings, a flux of more than 10 11 photons s -1 bandwidth -1 (0.2--0.5 nm) with a circular polarization of more than 90% in the wavelength range from 35 to 675 nm is achieved

Optimal Adaptive Statistical Iterative Reconstruction Percentage in Dual-energy Monochromatic CT Portal Venography.

Science.gov (United States)

Zhao, Liqin; Winklhofer, Sebastian; Yang, Zhenghan; Wang, Keyang; He, Wen

2016-03-01

The aim of this article was to study the influence of different adaptive statistical iterative reconstruction (ASIR) percentages on the image quality of dual-energy computed tomography (DECT) portal venography in portal hypertension patients. DECT scans of 40 patients with cirrhosis (mean age, 56 years) at the portal venous phase were retrospectively analyzed. Monochromatic images at 60 and 70 keV were reconstructed with four ASIR percentages: 0%, 30%, 50%, and 70%. Computed tomography (CT) numbers of the portal veins (PVs), liver parenchyma, and subcutaneous fat tissue in the abdomen were measured. The standard deviation from the region of interest of the liver parenchyma was interpreted as the objective image noise (IN). The contrast-noise ratio (CNR) between PV and liver parenchyma was calculated. The diagnostic acceptability (DA) and sharpness of PV margins were obtained using a 5-point score. The IN, CNR, DA, and sharpness of PV were compared among the eight groups with different keV + ASIR level combinations. The IN, CNR, DA, and sharpness of PV of different keV + ASIR groups were all statistically different (P ASIR and 70 keV + 0% ASIR (filtered back-projection [FBP]) combination, respectively, whereas the largest and smallest objective IN were obtained in the 60 keV + 0% ASIR (FBP) and 70 keV + 70% combination. The highest DA and sharpness values of PV were obtained at 50% ASIR for 60 keV. An optimal ASIR percentage (50%) combined with an appropriate monochromatic energy level (60 keV) provides the highest DA in portal venography imaging, whereas for the higher monochromatic energy (70 keV) images, 30% ASIR provides the highest image quality, with less IN than 60 keV with 50% ASIR. Copyright © 2015 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Inelastic neutron scattering experiments with the monochromatic imaging mode of the RITA-II spectrometer

DEFF Research Database (Denmark)

Bahl, Christian Robert Haffenden; Lefmann, Kim; Abrahamsen, Asger Bech

2006-01-01

Recently a monochromatic multiple data taking mode has been demonstrated for diffraction experiments using a RITA type cold neutron spectrometer with a multi-bladed analyser and a position-sensitive detector. Here, we show how this mode can be used in combination with a flexible radial collimator...

Incidence of neural tube defects in the natural radiation coastal areas of Kerala

International Nuclear Information System (INIS)

Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

All consecutive births in selected government hospitals in and around the high level natural background radiation areas (HLNRA) of Kerala were monitored for congenital malformations observable at birth since 1995. The HLNR area, a coastal strip of land about 55 km in length and 0.5 km in breadth from Purakkad in the north in Alleppey district to Sakthikulangara in the south of Quilon district, stands out among the most prominent background radiation areas of the world. Natural deposit of monazite sand, containing Thorium (8-10%), Uranium (0.3%) and corresponding decay products, is the source of elevated background radiation, ranging from < 1 to 45 mGy/year. Wide variation in dose, due to the patchy and non-uniform distribution of Monazite sand, enables in built controls. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. Areas with a mean radiation dose of more than 1.5 mGy/year were treated as HLNR areas and areas with a dose level of 1.5 mGy/year or less were treated as normal level radiation (NLNR) areas. The study carried out since 1995 does not seem to implicate HLNR in the incidence of neural tube defects among newborns

Towards an Optimized Monochromatization for direct Higgs Production in Future Circular e+ e- Colliders

CERN Document Server

García, M A Valdivia

2017-01-01

Direct s-channel Higgs production in e+e- collisions is of interest if the centre-of-mass energy spread can be reduced to be comparable to the width of the standard model Higgs boson. A monochromatization principle, previously proposed for several earlier lower-energy colliders, could be employed in order to achieve the desired reduction, by introducing a nonzero horizontal dispersion of opposite sign for the two colliding beams at the interaction point. In high-energy high-luminosity circular colliders, beamstrahlung may increase the energy spread and bunch length. The horizontal emittance blow up due to beamstrahlung, a new effect which was not present in past monochromatization proposals, may degrade the performance, especially the luminosity. We study, for the FCC-ee at 62.5~GeV beam energy, how we can optimize the IP optics parameters, along with the number of particles per bunch so as to obtain maximum luminosity at a desired target value of the collision energy spread.

Medical applications of synchrotron radiation

International Nuclear Information System (INIS)

Thomlinson, W.

1991-10-01

Ever since the first diagnostic x-ray was done in the United States on February 3, 1896, the application of ionizing radiation to the field of medicine has become increasingly important. Both in clinical medicine and basic research the use of x-rays for diagnostic imaging and radiotherapy is now widespread. Radiography, angiography, CAT and PETT scanning, mammography, and nuclear medicine are all examples of technologies developed to image the human anatomy. In therapeutic applications, both external and internal sources of radiation are applied to the battle against cancer. The development of dedicated synchrotron radiation sources has allowed exciting advances to take place in many of these applications. The new sources provide tunable, high-intensity monochromatic beams over a wide range of energies which can be tailored to specific programmatic needs. This paper surveys those areas of medical research in which synchrotron radiation facilities are actively involved

Medical applications of synchrotron radiation

International Nuclear Information System (INIS)

Thomlinson, W.

1992-01-01

Ever since the first diagnostic X-ray was done in the United States on February 3, 1896, the application of ionizing radiation to the field of medicine has become incrasingly important. Both in clinical medicine and basic research the use of X-rays for diagnostic imaging and radiotherapy is now widespread. Radiography, angiography, CAT and PETT scanning, mammography, and nuclear medicine are all examples of technologies developed to image the human anatomy. In therapeutic applications, both external and internal sources of radiation are applied to the battle against cancer. The development of dedicated synchrotron radiation sources has allowed exciting advances to take place in many of these applications. The new sources provide tunable, high-intensity monochromatic beams over a wide range of energies which can be tailored to specific programmatic needs. This paper surveys those areas of medical research in which synchrotron radiation facilities are actively involved. (orig.)

Contact microscopy with synchrotron radiation

International Nuclear Information System (INIS)

Panessa-Warren, B.J.

1985-10-01

Soft x-ray contact microscopy with synchrotron radiation offers the biologist and especially the microscopist, a way to morphologically study specimens that could not be imaged by conventional TEM, STEM or SEM methods (i.e. hydrated samples, samples easily damaged by an electron beam, electron dense samples, thick specimens, unstained low contrast specimens) at spatial resolutions approaching those of the TEM, with the additional possibility to obtain compositional (elemental) information about the sample as well. Although flash x-ray sources offer faster exposure times, synchrotron radiation provides a highly collimated, intense radiation that can be tuned to select specific discrete ranges of x-ray wavelengths or specific individual wavelengths which optimize imaging or microanalysis of a specific sample. This paper presents an overview of the applications of x-ray contact microscopy to biological research and some current research results using monochromatic synchrotron radiation to image biological samples. 24 refs., 10 figs

Studies for the development of a micro-focus monochromatic x-ray source with making use of a highly charged heavy ion beam

International Nuclear Information System (INIS)

Nakamura, Nobuyuki; Yoshiyasu, Nobuo; Nakayama, Ryo; Watanabe, Hirofumi

2008-01-01

We propose a new scheme for a micro-focus monochromatic X-ray source using a focused highly charged ion beam colliding with a solid surface. When highly charged ion approaches a surface, many electrons are captured into the ion and the so-called hollow atom is produced. The hollow atom will decay by emitting X-rays before and after hitting the surface. Such X-rays do not contain any contribution from bremsstrahlung, so that monochromatic X-rays can be obtained by using proper filters. For the first step of realizing the proposed scheme, an ion focusing system with a glass capillary has been developed. In order to study the monochromaticity of the emission, X-ray spectra from hollow atoms produced in the collisions between highly charged heavy ions and several surfaces have been observed. (author)

Comparison of monochromatic aberrations in young adults with different visual acuity and refractive errors.

Science.gov (United States)

Yazar, Seyhan; Hewitt, Alex W; Forward, Hannah; McKnight, Charlotte M; Tan, Alex; Mountain, Jenny A; Mackey, David A

2014-03-01

To compare the monochromatic aberrations in a large cohort of 20-year-old Australians with differing levels of visual acuity and explore the relationship between these aberrations and refractive error. Lions Eye Institute, Perth, Western Australia, Australia. Cross-sectional analysis of a population-based cohort. Monochromatic aberrations were measured using a Zywave II wavefront aberrometer with natural pupils in a dark room. The logMAR corrected distance visual acuity (CDVA) was measured monocularly under normal illumination. Cycloplegic autorefraction was also performed. The study enrolled 2039 eyes of 1040 participants. Data from 1007 right eyes were analyzed. The median CDVA and spherical equivalent were -0.06 logMAR (interquartile range [IQR], -0.10 to 0.00) and +0.25 diopters (D) (IQR, -0.38 to 0.63), respectively. The median 6.0 mm higher-order aberration (HOA) was 0.58 μm (IQR, 0.44 to 0.79). Coma-like aberrations and 3rd-, 4th-, and 5th-order HOAs were significantly different between subjects with a CDVA of -0.10 logMAR or better and those with a CDVA worse than -0.10 logMAR. Fourth-order aberrations Z(4,-4) (P=.024) and Z(4,-2) (P=.029) and 2nd-order aberration Z(2,0) (Peyes, emmetropic eyes, and hyperopic eyes. Subjects with higher myopia had slightly higher total HOAs. The HOAs in this population were marginally higher than previously reported values. The findings confirm there is a difference in monochromatic aberrations between different vision and refractive groups. Results in this study will benefit decision-making processes in the clinical setting. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Near-ultraviolet radiation blocks SOS responses to DNA damage in Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Turner, M.A.; Eisenstark, A.

1984-01-01

Escherichia coli cells in which the recA promoter is fused to a lac structural gene, (Mu) Mud(Ap,lac)::rec, were irradiated with two far-ultraviolet light wavelengths (254 and 290 nm), selected monochromatic near-ultraviolet (NUV) wavelengths 313 nm, 334 nm, 365 nm, or broad band solar-UV (290-420 nm) from a solar simulator. Irradiation with the two far-ultraviolet wavelengths was followed by high yields of ..beta..-galactosidase, lambda prophage induction, and Weigle reactivation. These end points were not observed after irradiation with the selected NUV wavelengths or the broad spectrum solar-UV. Thus, neither broad spectrum solar-UV nor monochromatic NUV wavelengths resulted in the derepression of the recA promoter. Further, prior exposure of the cells either to the selected monochromatic NUV wavelengths or to solar-UV inhibited a) the induction of ..beta..-galactosidase by subsequent 254-nm radiation, b) subsequent 254-nm induction of lambda prophage, c) Weigle reactivation, and d) mutation frequency. These observations are consistent with the hypothesis that NUV blocks subsequent recA protease action.

Pustular Palmoplantar Psoriasis Successfully Treated with Nb-UVB Monochromatic Excimer Light: A Case-Report

Directory of Open Access Journals (Sweden)

Serena Gianfaldoni

2017-07-01

Full Text Available Barber’s palmoplantar pustulosis (PPP is a form of localised pustular psoriasis, affecting the palmar and plantar surfaces. It is a chronic disease, with a deep impact on the patients’ quality of life. The Authors discuss a case of Baber Psoriasis successfully treated with monochromatic excimer light.

Relation between cancer incidence or mortality and external natural background radiation in Japan

International Nuclear Information System (INIS)

Ujeno, Y.

1983-01-01

Analysis was performed on the relationships between the organ dose-equivalent rate due to natural background radiation (mSv/a) and three parameters of cancer risk: the age-adjusted cancer incidence (patients x 10 5 persons x a -1 ) in 13 large areas, the standardized mortality ratio of cancers in 46 large areas, and the cancer mortality in the population aged more than 40 years old (cancer deaths x 10 5 persons x a -1 ) in 649 small areas. The age-adjusted liver cancer incidence in males fitted the exponential model significantly (p<0.01) and the relationship of stomach cancer mortality of aged males in small areas fitted the linear model significantly (p<0.05). No relationship was observed with regard to female cancer in either case. The relationships between the three parameters and various other cancers of both sexes were not statistically significant. (author)

Enhanced possibilities of section topography at a third-generation synchrotron radiation facility

International Nuclear Information System (INIS)

Medrano, C.; Rejmankova, P.; Ohler, M.; Matsouli, I.

1997-01-01

The authors show the new possibilities of section topography techniques at a third-generation synchrotron radiation facility, taking advantage of the high performances of this machine. Examples of the 1) so-called multiple sections, 2) visibility of weakly misoriented regions, 3) study of thick samples, 4) monochromatic and 5) realtime sections are presented

Low luminance/eyes closed and monochromatic stimulations reduce variability of flash visual evoked potential latency

Directory of Open Access Journals (Sweden)

Senthil Kumar Subramanian

2013-01-01

Full Text Available Context: Visual evoked potentials are useful in investigating the physiology and pathophysiology of the human visual system. Flash visual evoked potential (FVEP, though technically easier, has less clinical utility because it shows great variations in both latency and amplitude for normal subjects. Aim: To study the effect of eye closure, low luminance, and monochromatic stimulation on the variability of FVEPs. Subjects and Methods: Subjects in self-reported good health in the age group of 18-30 years were divided into three groups. All participants underwent FVEP recording with eyes open and with white light at 0.6 J luminance (standard technique. Next recording was done in group 1 with closed eyes, group 2 with 1.2 and 20 J luminance, and group 3 with red and blue lights, while keeping all the other parameters constant. Two trials were given for each eye, for each technique. The same procedure was repeated at the same clock time on the following day. Statistical Analysis: Variation in FVEP latencies between the individuals (interindividual variability and the variations within the same individual for four trials (intraindividual variability were assessed using coefficient of variance (COV. The technique with lower COV was considered the better method. Results: Recording done with closed eyes, 0.6 J luminance, and monochromatic light (blue > red showed lower interindividual and intraindividual variability in P2 and N2 as compared to standard techniques. Conclusions: Low luminance flash stimulations and monochromatic light will reduce FVEP latency variability and may be clinically useful modifications of FVEP recording technique.

Damage to adenosine-triphosphate induced by monochromatic X rays around the K shell absorption edge of phosphorus

International Nuclear Information System (INIS)

Watanabe, Ritsuko; Ishikawa, Mitsuo; Takakura, Kaoru; Kobayashi, Katsumi

1992-01-01

Adenosine-triphosphate (ATP) is well known to have an important role in the energy metabolism in biological systems. The purpose of this study is to clarify the radiation effects on ATP specific to inner shell ionization. ATP, in concentrated aqueous solution, was irradiated with monochromatic X rays having energies of the resonance absorption peak of the phosphorus K shell, 2.153 keV, and slightly below and above the peak, 2.145 keV and 2.160 keV, selected from synchrotron radiation. Adenine, Adenosine 5'monophosphate (5'AMP) and Adenosine 5'diphosphate (5'ADP) were obtained as radioproducts by the method of high performance liquid chromatography (HPLC). G values of these products were calculated on the basis of the absorbed energy. When the ATP solution of 0.282 mol/l was irradiated with 2.160 keV X rays which can ionize the K shell of phosphorus, G values of Adenine, 5'AMP and 5'ADP were estimated to be 1.4, 0.40 and 0.46, respectively. These values were respectively 1.3, 2.9 and 3.8 times higher than those obtained upon irradiation with 2.146 keV X rays which cannot ionize the K shell of phosphorus. These energy dependent enhancements may reflect the difference in energy absorption processes, especially the Auger cascade in phosphorus may be suspected to play an important role in these enhancements

Design of a dedicated beamline for THz coherent synchrotron radiation at UVSOR-III

International Nuclear Information System (INIS)

Kimura, Shin-ichi; Nakamura, Eiken; Imura, Keiichiro; Katoh, Masahiro; Hosaka, Masahito; Takahashi, Toshiharu

2012-01-01

We report the design of a THz beamline for coherent synchrotron radiation (CSR) at the UVSOR-III very-low-emittance synchrotron radiation light source. The emitted THz-CSR is collected by a three-dimensional 'magic mirror', which is a perfect collecting mirror for bending-magnet radiation with an acceptance angle of 288 mrad (H) × 80 mrad (V). A quasi-monochromatic THz-CSR with an average flux of 104 μW/0.1 % b.w. and a peak power of 120 nJ/pulse/0.1 % b.w. is expected at the beamline.

Investigation of the effects of monochromatic lights combination on Phalaenopsis orchid and chrysanthemum in vitro plant growth

International Nuclear Information System (INIS)

Le Tien Thanh; Nguyen Tuong Mien; Huynh Thi Trung; Vu Thi Trac; Pham Van Nhi

2016-01-01

Eleven independent monochromatic light combination systems were established using super blue and red light LEDs. These are adjustable for mixing ratio of red and blue lights, the intensity and time for illumination. A fluorescent light illumination system was included as control. These were used to implement experiments for investigation effects of monochromatic lights combination in in vitro plantlet fully-forming stage on in vitro plantlet fully-forming and on the development of plant in nursery of chrysanthemum and Phalaenopsis orchid. Results from these experiments showed that illumination with intensity of 750 lx and light mixture of 20% blue-80% red is suitable for Phalaenopsis orchid; illumination with intensity of 1100 lx and light mixture of 90% red light-10% blue light is suitable for chrysanthemum. (author)

Diamond identification

International Nuclear Information System (INIS)

Lang, A.R.

1979-01-01

Methods of producing sets of records of the internal defects of diamonds as a means of identification of the gems by x-ray topography are described. To obtain the records one can either use (a) monochromatic x-radiation reflected at the Bragg angle from crystallographically equivalent planes of the diamond lattice structure, Bragg reflections from each such plane being recorded from a number of directions of view, or (b) white x-radiation incident upon the diamond in directions having a constant angular relationship to each equivalent axis of symmetry of the diamond lattice structure, Bragg reflections being recorded for each direction of the incident x-radiation. By either method an overall point-to-point three dimensional representation of the diamond is produced. (U.K.)

Can Angiotensin-Converting Enzyme Inhibitors Reduce the Incidence, Severity, and Duration of Radiation Proctitis?

International Nuclear Information System (INIS)

Alashkham, Abduelmenem; Paterson, Catherine; Rauchhaus, Petra; Nabi, Ghulam

2016-01-01

Purpose: To determine whether participants taking angiotensin-converting enzyme inhibitors (ACEIs) and treated with radical radiation therapy with neoadjuvant/adjuvant hormone therapy have less incidence, severity, and duration of radiation proctitis. Methods and Materials: A propensity score analysis of 817 patients who underwent radical radiation therapy with neoadjuvant or adjuvant hormone therapy as primary line management in a cohort study during 2009 to 2013 was conducted. Patients were stratified as follows: group 1, hypertensive patients taking ACEIs (as a study group); group 2, nonhypertensive patients not taking ACEIs; and group 3, hypertensive patients not taking ACEIs (both as control groups). The incidence, severity, and duration of proctitis were the main outcome. χ"2 tests, Mann-Whitney U tests, analysis of variance, risk ratio (RR), confidence interval (CI), Kaplan-Meier plots, and log-rank tests were used. Results: The mean age of the participants was 68.91 years, with a follow-up time of 3.38 years. Based on disease and age-matched comparison, there was a statistically significant difference of proctitis grading between the 3 groups: χ"2 (8, n=308) = 72.52, P<.001. The Mann-Whitney U test indicated that grades of proctitis were significantly lower in hypertensive patients taking ACEIs than in nonhypertensive patients not taking ACEIs and hypertensive patients not taking ACEIs (P<.001). The risk ratio (RR) of proctitis in hypertensive patients taking ACEIs was significantly lower than in hypertensive patients not taking ACEIs (RR 0.40, 95% CI 0.30-0.53, P<.001) and in nonhypertensive patients not taking ACEIs (RR 0.58, 95% CI 0.44-0.77, P<.001). Time to event analysis revealed that hypertensive patients taking ACEIs were significantly different from the control groups (P<.0001). Furthermore, hypertensive patients taking ACEIs had significantly faster resolution of proctitis (P<.0001). Conclusion: Patients who were taking ACEIs were

Can Angiotensin-Converting Enzyme Inhibitors Reduce the Incidence, Severity, and Duration of Radiation Proctitis?

Energy Technology Data Exchange (ETDEWEB)

Alashkham, Abduelmenem, E-mail: alashkham@yahoo.com [Academic Section of Urology, Division of Cancer Research, School of Medicine, University of Dundee, Scotland (United Kingdom); Paterson, Catherine [Academic Section of Urology, Division of Cancer Research, School of Medicine, University of Dundee, Scotland (United Kingdom); Rauchhaus, Petra [Tayside Clinical Trials Unit, School of Medicine, University of Dundee, Scotland (United Kingdom); Nabi, Ghulam [Academic Section of Urology, Division of Cancer Research, School of Medicine, University of Dundee, Scotland (United Kingdom)

2016-01-01

Purpose: To determine whether participants taking angiotensin-converting enzyme inhibitors (ACEIs) and treated with radical radiation therapy with neoadjuvant/adjuvant hormone therapy have less incidence, severity, and duration of radiation proctitis. Methods and Materials: A propensity score analysis of 817 patients who underwent radical radiation therapy with neoadjuvant or adjuvant hormone therapy as primary line management in a cohort study during 2009 to 2013 was conducted. Patients were stratified as follows: group 1, hypertensive patients taking ACEIs (as a study group); group 2, nonhypertensive patients not taking ACEIs; and group 3, hypertensive patients not taking ACEIs (both as control groups). The incidence, severity, and duration of proctitis were the main outcome. χ{sup 2} tests, Mann-Whitney U tests, analysis of variance, risk ratio (RR), confidence interval (CI), Kaplan-Meier plots, and log-rank tests were used. Results: The mean age of the participants was 68.91 years, with a follow-up time of 3.38 years. Based on disease and age-matched comparison, there was a statistically significant difference of proctitis grading between the 3 groups: χ{sup 2} (8, n=308) = 72.52, P<.001. The Mann-Whitney U test indicated that grades of proctitis were significantly lower in hypertensive patients taking ACEIs than in nonhypertensive patients not taking ACEIs and hypertensive patients not taking ACEIs (P<.001). The risk ratio (RR) of proctitis in hypertensive patients taking ACEIs was significantly lower than in hypertensive patients not taking ACEIs (RR 0.40, 95% CI 0.30-0.53, P<.001) and in nonhypertensive patients not taking ACEIs (RR 0.58, 95% CI 0.44-0.77, P<.001). Time to event analysis revealed that hypertensive patients taking ACEIs were significantly different from the control groups (P<.0001). Furthermore, hypertensive patients taking ACEIs had significantly faster resolution of proctitis (P<.0001). Conclusion: Patients who were taking ACEIs were

Association of UV radiation with Parkinson disease incidence: A nationwide French ecologic study

International Nuclear Information System (INIS)

Kravietz, Adam; Kab, Sofiane; Wald, Lucien; Dugravot, Aline; Singh-Manoux, Archana; Moisan, Frédéric; Elbaz, Alexis

2017-01-01

Background: Vitamin D is thought to contribute to brain health, but it is unclear whether low vitamin D levels are associated with increased incidence of Parkinson's disease (PD). Using ultraviolet B (UV-B) as a surrogate for vitamin D levels, we conducted a nationwide ecologic study in France in order to examine the association of UV-B with PD incidence. Methods: We used French national drug claims databases to identify PD cases using a validated algorithm. UV-B data from the solar radiation database were derived from satellite images. We estimated PD incidence (2010–2012) at the canton level (small administrative French unit) and used multilevel Poisson regression to examine its association with UV-B (2005 annual average), after adjustment for age, sex, deprivation index, density of neurologists, smoking, proportion of agricultural land, and vitamin D supplementation. Results: Analyses are based on 69,010 incident PD patients. The association between UV-B and PD incidence was quadratic (P<0.001) and modified by age (P<0.001). Below 70y, incidence was higher in the bottom quintile (relative risk, RR Q1:45-49y =1.18, 95% CI=1.08–1.29) compared with the middle UV-B quintile, and lower in the top quintile (RR Q5:45-49y =0.85 [0.77–0.94]). An opposite pattern was observed in older subjects (RR Q1:85-89y =0.92 [0.89–0.96]; RR Q5:85-89y =1.06 [1.02–1.11]). Analysis based on continuous UV-B yielded similar conclusions. Conclusions: In this nationwide study, there was an age-dependent quadratic association between UV-B and PD incidence. This study suggests that reasonable UV-B exposure is associated with lower PD risk in younger persons and that future studies should examine dose-response relations and take age into account. - Highlights: • There is an age-dependent quadratic association between UV-B and PD incidence. • Reasonable UV-B exposure is beneficial in younger persons for the risk of PD. • Our findings are consistent with a role of vitamin D

Effect of radiation environment on radiation use efficiency and growth of sunflower

International Nuclear Information System (INIS)

Bange, M.P.; Hammer, G.L.; Rickert, K.G.

1997-01-01

The level of incident radiation and the proportion of radiation that is diffuse affects radiation use efficiency (RUE) in crops. However, the degree of this effect, and its importance to growth and yield of sunflower (Helianthus annuus L.) have not been established. A field experiment was conducted to investigate the effects of radiation environment on RUE, growth, and yield of sunflower. A fully irrigated crop was sown on an alluvial-prairie soil (Fluventic Haplustoll) and was exposed to three distinct radiation environments. In two treatments, the level of incident radiation was reduced by 14 and 20% by suspending two different types of polyethylene plastic films well above the crop. In addition to the reductions in incident radiation, the proportion of radiation that was diffuse was increased by about 14% in these treatments. Lower incident radiation and increased proportion of diffuse radiation had no effect on total biomass, phenology, leaf area, and the canopy light extinction coefficient (k = 0.89). However, yield was reduced in shaded treatments due to smaller grain size and lower harvest index. Although crop RUE measured over the entire crop cycle (1.25 g/MJ) did not differ significantly among treatments, there was a trend where RUE compensated for less intercepted incident radiation. Theoretical derivations of the response of RUE to different levels of incident radiation supported this finding. Shaded sunflower crops have the ability to produce biomass similar to unshaded crops by increasing RUE, but have lower harvest indices

High resolution, monochromatic x-ray topography capability at CHESS

Energy Technology Data Exchange (ETDEWEB)

Finkelstein, K. D., E-mail: kdf1@cornell.edu; Pauling, A.; Brown, Z. [CHESS, Cornell University, Ithaca, NY (United States); Jones, R. [Department of Physics, University of Connecticut, Storrs, CT (United States); Tarun, A.; Misra, D. S. [IIa Technologies (Singapore); Jupitz, S. [St. Mary’s College of Maryland, St. Mary’s City, MD (United States); Sagan, D. C. [CLASSE, Cornell University, Ithaca, NY (United States)

2016-07-27

CHESS has a monochromatic x-ray topography capability serving continually expanding user interest. The setup consists of a beam expanding monochromator, 6-circle diffactometer, and CHESS designed CMOS camera with real time sample-alignment capability. This provides rocking curve mapping with angle resolution as small as 2 µradians, spatial resolution to 3 microns, and field of view up to 7mm. Thus far the capability has been applied for: improving CVD-diamond growth, evaluating perfection of ultra-thin diamond membranes, correlating performance of diamond-based electronics with crystal defect structure, and defect analysis of single crystal silicon carbide. This paper describes our topography system, explains its capabilities, and presents experimental results from several applications.

High resolution, monochromatic x-ray topography capability at CHESS

International Nuclear Information System (INIS)

Finkelstein, K. D.; Pauling, A.; Brown, Z.; Jones, R.; Tarun, A.; Misra, D. S.; Jupitz, S.; Sagan, D. C.

2016-01-01

CHESS has a monochromatic x-ray topography capability serving continually expanding user interest. The setup consists of a beam expanding monochromator, 6-circle diffactometer, and CHESS designed CMOS camera with real time sample-alignment capability. This provides rocking curve mapping with angle resolution as small as 2 µradians, spatial resolution to 3 microns, and field of view up to 7mm. Thus far the capability has been applied for: improving CVD-diamond growth, evaluating perfection of ultra-thin diamond membranes, correlating performance of diamond-based electronics with crystal defect structure, and defect analysis of single crystal silicon carbide. This paper describes our topography system, explains its capabilities, and presents experimental results from several applications.

Impact of curcumin supplementation in monochromatic light on lipid serum profile of sexually mature female Magelang ducks

Directory of Open Access Journals (Sweden)

K. Kasiyati

2018-03-01

Full Text Available An experiment was conducted to study the effect of curcumin supplementation inexpose monochromatic light on serum lipid concentrations of sexually mature female magelang duck. One hundred and ninety two female magelang ducks were assigned into a completely randomized design with a 4×4 factorial arrangement and each experimental unit was repeated 3 times, each with 4 female magelang ducks. The first factor was dose of curcumin supplementation consisted of 4 levels i.e., 0, 9, 18, and 36 mg/duck/day. The second factor was the color of monochromatic light consisted of 4 levels i.e., white, red, green, and blue colors. The data were analyzed by two-way ANOVA. The result showed that serum concentrations of triglyceride, cholesterol, very low density lipoprotein (VLDL, and low density lipoprotein (LDL were lower (P<0.05 while high density lipoprotein (HDL were higher (P<0.05 in experimental ducks supplemented with a curcumin dose of 36 mg/duck/day in variety of monochromatic light colors compared to control experimental ducks without curcumin supplementation. The curcumin doses of 18 or 36 mg/duck/day within red, green, or blue light had the potential to modulate lipid metabolism, as indicated by the increased serum concentration of HDL and the decreased serum concentrations of triglyceride, cholesterol, VLDL, and LDL of the experimental female magelang ducks.

Quantifying metal artefact reduction using virtual monochromatic dual-layer detector spectral CT imaging in unilateral and bilateral total hip prostheses

Energy Technology Data Exchange (ETDEWEB)

Wellenberg, R.H.H., E-mail: r.h.wellenberg@amc.uva.nl [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Boomsma, M.F., E-mail: m.f.boomsma@isala.nl [Department of Radiology, Isala, Zwolle (Netherlands); Osch, J.A.C. van, E-mail: j.a.c.van.osch@isala.nl [Department of Radiology, Isala, Zwolle (Netherlands); Vlassenbroek, A., E-mail: alain.vlassenbroek@philips.com [Philips Medical Systems, Brussels (Belgium); Milles, J., E-mail: julien.milles@philips.com [Philips Medical Systems, Eindhoven (Netherlands); Edens, M.A., E-mail: m.a.edens@isala.nl [Department of Innovation and Science, Isala, Zwolle (Netherlands); Streekstra, G.J., E-mail: g.j.streekstra@amc.uva.nl [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Slump, C.H., E-mail: c.h.slump@utwente.nl [MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede (Netherlands); Maas, M., E-mail: m.maas@amc.uva.nl [Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

2017-03-15

Highlights: • Dual-layer detector CT reduces metal artefacts at high monochromatic energies (keV). • 130 keV images were optimal based on quantitative analysis on CNRs. • Optimal keVs varied from 74 to 150 keV for different hip prostheses configurations. • The Titanium alloy resulted in less severe artefacts compared to the Cobalt alloy. • Severe metal artefacts, caused by extensive photon-starvation, were not reduced. - Abstract: Purpose: To quantify the impact of prosthesis material and design on the reduction of metal artefacts in total hip arthroplasties using virtual monochromatic dual-layer detector Spectral CT imaging. Methods: The water-filled total hip arthroplasty phantom was scanned on a novel 128-slice Philips IQon dual-layer detector Spectral CT scanner at 120-kVp and 140-kVp at a standard computed tomography dose index of 20.0 mGy. Several unilateral and bilateral hip prostheses consisting of different metal alloys were inserted and combined which were surrounded by 18 hydroxyapatite calcium carbonate pellets representing bone. Images were reconstructed with iterative reconstruction and analysed at monochromatic energies ranging from 40 to 200 keV. CT numbers in Hounsfield Units (HU), noise measured as the standard deviation in HU, signal-to-noise-ratios (SNRs) and contrast-to-noise-ratios (CNRs) were analysed within fixed regions-of-interests placed in and around the pellets. Results: In 70 and 74 keV virtual monochromatic images the CT numbers of the pellets were similar to 120-kVp and 140-kVp polychromatic results, therefore serving as reference. A separation into three categories of metal artefacts was made (no, mild/moderate and severe) where pellets were categorized based on HU deviations. At high keV values overall image contrast was reduced. For mild/moderate artefacts, the highest average CNRs were attained with virtual monochromatic 130 keV images, acquired at 140-kVp. Severe metal artefacts were not reduced. In 130 keV images

Sensitivity and specificity of monochromatic photography of the ocular fundus in differentiating optic nerve head drusen and optic disc oedema: optic disc drusen and oedema.

Science.gov (United States)

Gili, Pablo; Flores-Rodríguez, Patricia; Yangüela, Julio; Orduña-Azcona, Javier; Martín-Ríos, María Dolores

2013-03-01

Evaluation of the efficacy of monochromatic photography of the ocular fundus in differentiating optic nerve head drusen (ONHD) and optic disc oedema (ODE). Sixty-six patients with ONHD, 31 patients with ODE and 70 healthy subjects were studied. Colour and monochromatic fundus photography with different filters (green, red and autofluorescence) were performed. The results were analysed blindly by two observers. The sensitivity, specificity and interobserver agreement (k) of each test were assessed. Colour photography offers 65.5 % sensitivity and 100 % specificity for the diagnosis of ONHD. Monochromatic photography improves sensitivity and specificity and provides similar results: green filter (71.20 % sensitivity, 96.70 % specificity), red filter (80.30 % sensitivity, 96.80 % specificity), and autofluorescence technique (87.8 % sensitivity, 100 % specificity). The interobserver agreement was good with all techniques used: autofluorescence (k = 0.957), green filter (k = 0.897), red filter (k = 0.818) and colour (k = 0.809). Monochromatic fundus photography permits ONHD and ODE to be differentiated, with good sensitivity and very high specificity. The best results were obtained with autofluorescence and red filter study.

Sci-Fri AM: Quality, Safety, and Professional Issues 06: An Evaluation of Incident Reporting and Learning using the Canadian National System for Incident Reporting – Radiation Treatment

Energy Technology Data Exchange (ETDEWEB)

Montgomery, Logan; Kildea, John [McGill University Health Centre (Canada)

2016-08-15

We report on the development and clinical deployment of an in-house incident reporting and learning system that implements the taxonomy of the Canadian National System for Incident Reporting – Radiation Treatment (NSIR-RT). In producing our new system, we aimed to: Analyze actual incidents, as well as potentially dangerous latent conditions. Produce recommendations on the NSIR-RT taxonomy. Incorporate features to divide reporting responsibility among clinical staff and expedite incident categorization within the NSIR-RT framework. Share anonymized incident data with the national database. Our multistep incident reporting workflow is focused around an initial report and a detailed follow-up investigation. An investigator, chosen at the time of reporting, is tasked with performing the investigation. The investigation feature is connected to our electronic medical records database to allow automatic field population and quick reference of patient and treatment information. Additional features include a robust visualization suite, as well as the ability to flag incidents for discussion at monthly Risk Management meetings and task ameliorating actions to staff. Our system was deployed into clinical use in January 2016. Over the first three months of use, 45 valid incidents were reported; 31 of which were reported as actual incidents as opposed to near-misses or reportable circumstances. However, we suspect there is ambiguity within our centre in determining the appropriate event type, which may be arising from the taxonomy itself. Preliminary trending analysis aided in revealing workflow issues pertaining to storage of treatment accessories and treatment planning delays. Extensive analysis will be undertaken as more data are accrued.

Sci-Fri AM: Quality, Safety, and Professional Issues 06: An Evaluation of Incident Reporting and Learning using the Canadian National System for Incident Reporting – Radiation Treatment

International Nuclear Information System (INIS)

Montgomery, Logan; Kildea, John

2016-01-01

We report on the development and clinical deployment of an in-house incident reporting and learning system that implements the taxonomy of the Canadian National System for Incident Reporting – Radiation Treatment (NSIR-RT). In producing our new system, we aimed to: Analyze actual incidents, as well as potentially dangerous latent conditions. Produce recommendations on the NSIR-RT taxonomy. Incorporate features to divide reporting responsibility among clinical staff and expedite incident categorization within the NSIR-RT framework. Share anonymized incident data with the national database. Our multistep incident reporting workflow is focused around an initial report and a detailed follow-up investigation. An investigator, chosen at the time of reporting, is tasked with performing the investigation. The investigation feature is connected to our electronic medical records database to allow automatic field population and quick reference of patient and treatment information. Additional features include a robust visualization suite, as well as the ability to flag incidents for discussion at monthly Risk Management meetings and task ameliorating actions to staff. Our system was deployed into clinical use in January 2016. Over the first three months of use, 45 valid incidents were reported; 31 of which were reported as actual incidents as opposed to near-misses or reportable circumstances. However, we suspect there is ambiguity within our centre in determining the appropriate event type, which may be arising from the taxonomy itself. Preliminary trending analysis aided in revealing workflow issues pertaining to storage of treatment accessories and treatment planning delays. Extensive analysis will be undertaken as more data are accrued.

Response of TAPS to monochromatic photons with energies between 45 and 790 MeV

Energy Technology Data Exchange (ETDEWEB)

Gabler, A.R. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Doering, W. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Fuchs, M. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Krusche, B. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Metag, V. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Novotny, R. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Roebig-Landau, M. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Stroeher, H. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Tries, V. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Molenaar, C. (Kernfysisch Versneller Instituut, Groningen (Netherlands)); Loehner, H. (Kernfysisch Versneller Instituut, Groningen (Netherlands)); Van Pol, J.H

1994-07-15

The Two Arm Photon Spectrometer TAPS - comprising 384 plastic-BaF[sub 2] scintillator telescopes - was tested with monochromatic photons in the energy range between 45 and 790 MeV. The energy resolution for a collimated photon beam hitting the central detector module was determined to [sigma]/E=0.59%xE[sup -1/2][sub [gamma

Solar ultraviolet radiation in Syria measurements and relationship with skin cancer incidence

International Nuclear Information System (INIS)

Othman, I; Baydon, S.A.; Dawood, S.

1994-11-01

Seasonal variations of solar UVB (285-320) and UVA (320-400) were measured in three sites in Syria (33-37 N sup O) for two years: 1992-1993. UVB measurements were performed using polysulphone films and Robertson-Berger meter, while UVA measurements were done by NVA intensity meter. Two sets of measurements were carried out : - Maximal daily doses three times a week (every other day) - Diurnal variations from sun-rise to sun-set every two hours twice a month (every fortnight). The biological consequences of ultraviolet radiation withreference to some epidemiological data of skin cancer incidence in Syria since 1980 were discussed .(author). 36 refs., 21 figs., 11 tabs

Incident report and estimates of personnel exposure for a staff present in maze corridor of linac room while radiation beam on

International Nuclear Information System (INIS)

Ravichandran, R.; Davis, C.A.; Ghamrawy, Kamal El; Arunkumar, L.S.

2007-01-01

The radiation safety features of high energy linear accelerator installations include primary and secondary barriers made of concrete (radiation bunkers), provision of maze wall for eliminating first scatter reaching the entrance door, locating room entrance perpendicular to maze corridor to reduce neutron dose. In addition, special motorized doors with lead lining and paraffin blocks, electrically interlocked to beam on-off system is provided for radiation safety. A radiation incident took place involving presence of a staff inside the Clinac 2300 CD room in September 2006 has been described

Factors influencing incidence of acute grade 2 morbidity in conformal and standard radiation treatment of prostate cancer

International Nuclear Information System (INIS)

Hanks, Gerald E.; Schultheiss, Timothy E.; Hunt, Margie A.; Epstein, Barry

1995-01-01

Purpose: The fundament hypothesis of conformal radiation therapy is that tumor control can be increased by using conformal treatment techniques that allow a higher tumor dose while maintaining an acceptable level of complications. To test this hypothesis, it is necessary first to estimate the incidence of morbidity for both standard and conformal fields. In this study, we examine factors that influence the incidence of acute grade 2 morbidity in patients treated with conformal and standard radiation treatment for prostate cancer. Methods and Materials: Two hundred and forty-seven consecutive patients treated with conformal technique are combined with and compared to 162 consecutive patients treated with standard techniques. The conformal technique includes special immobilization by a cast, careful identification of the target volume in three dimensions, localization of the inferior border of the prostate using the retrograde urethrogram, and individually shaped portals that conform to the Planning Target Volume (PTV). Univariate analysis compares differences in the incidence of RTOG-EORTC grade two acute morbidity by technique, T stage, age, irradiated volume, and dose. Multivariate logistic regression includes these same variables. Results: In nearly all categories, the conformal treatment group experienced significantly fewer acute grade 2 complications than the standard treatment group. Only volume (prostate ± whole pelvis) and technique (conformal vs. standard) were significantly related to incidence of morbidity on multivariate analysis. When dose is treated as a continuous variable (rather than being dichotomized into two levels), a trend is observed on multivariate analysis, but it does not reach significant levels. The incidence of acute grade 2 morbidity in patients 65 years or older is significantly reduced by use of the conformal technique. Conclusion: The conformal technique is associated with fewer grade 2 acute toxicities for all patients. This

Establishment Of Illumination System For Investigation Of Monochromatic Lights Combination Effects On In Vitro Plant Growth

International Nuclear Information System (INIS)

Le Tien Thanh; Le Ngoc Trieu; Nguyen Tuong Mien; Huynh Thi Trung; Phan Quoc Minh

2014-01-01

Super blue and red light LEDs and other electric, electronic components are used to design and establish 11 independent illumination systems, each system can arbitrarily control to operate at 55 molarities of illumination which are different from together in monochromatic lights combination and total illumination intensity based on the microcontrollers. Programs for loading to microcontrollers were created to base on theoretical calculation and experimental correction. The illumination cycles can be controlled by setting the timer. These 11 systems and another fluorescent light illumination were used to execute the experiment for investigation the effects of monochromatic lights combination on in vitro shoot proliferation stage in Chrysanthemum and Phalaenopsis orchid. Results from this experiment showed that illumination intensity of 400 lux is suitable for chrysanthemum, 750 lux is suitable for Phalaenopsis orchid and rate of 70% red light-30% blue light are suitable for both kinds of these plants. (author)

Radiative transfer with finite elements. Pt. 1. Basic method and tests

Energy Technology Data Exchange (ETDEWEB)

Richling, S. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Astrophysik; Meinkoehn, E. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Astrophysik]|[Heidelberg Univ. (Germany). Inst. fuer Angewandte Mathematik; Kryzhevoi, N. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Astrophysik]|[Heidelberg Univ. (DE). Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen (IWR); Kanschat, G. [Heidelberg Univ. (Germany). Inst. fuer Angewandte Mathematik]|[Heidelberg Univ. (DE). Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen (IWR)

2001-10-01

A finite element method for solving the monochromatic radiation transfer equation including scattering in three dimensions is presented. The algorithm employs unstructured grids which are adaptively refined. Adaptivity as well as ordinate parallelization reduce memory requirements and execution time and make it possible to calculate the radiation field across several length scales for objects with strong opacity gradients. An a posteriori error estimate for one particular quantity is obtained by solving the dual problem. The application to a sample of test problems reveals the properties of the implementation. (orig.)

Free-Free Transitions in the Presence of Laser Fields and Debye Potential at Very Low Incident Electron Energies

Science.gov (United States)

Bhatia, Anand

2012-01-01

We study the free-free transition in electron-helium ion in the ground state and embedded in a Debye potential in the presence of an external laser field at very low incident electron energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen as monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing Volkov wave function for it. The scattering wave function for the incident electron on the target embedded in a Debye potential is solved numerically by taking into account the effect of electron exchange. We calculate the laser-assisted differential and total cross sections for free-free transition for absorption/emission of a single photon or no photon exchange. The results will be presented at the conference.

Medical applications with synchrotron radiation in Japan

Energy Technology Data Exchange (ETDEWEB)

Takeda, T.; Itai, Y. [Univ. of Tsukuba, Inst. of Clinical Medicine, Tsukuba (Japan); Hyodo, K.; Ando, M. [KEK, Tsukuba (Japan); Akatsuka, T. [Yamagata Univ., Faculty of Engineering, Yamagata (Japan); Uyama, C. [National Cardiovascular Centre, Suita (Japan)

1998-05-01

In Japan, various medical applications of synchrotron X-ray imaging, such as angiography, monochromatic X-ray computed tomography (CT), radiography and radiation therapy, are being developed. In particular, coronary arteriography (CAG) is quite an important clinical application of synchrotron radiation. Using a two-dimensional imaging method, the first human intravenous CAG was carried out at KEK in May 1996; however, further improvements of image quality are required in clinical practice. On the other hand, two-dimensional aortographic CAG revealed canine coronary arteries as clearly as those on selective CAG, and coronary arteries less than 0.2 mm in diameter. Among applications of synchrotron radiation to X-ray CT, phase-contrast X-ray CT and fluorescent X-ray CT are expected to be very interesting future applications of synchrotron radiation. For actual clinical applications of synchrotron radiation, a medical beamline and a laboratory are now being constructed at SPring-8 in Harima. 55 refs.

X-ray topography under conditions of monochromatic spherical wave diffraction

International Nuclear Information System (INIS)

Aristov, V.V.; Polovinkina, V.I.; Ibhikawa, Tetsuya; Kiduta, Seishi.

1981-01-01

An X-ray topographic scheme was developed in which there is a large distance between the X-ray source and the specimen. A monochromatic X-ray beam with an angular divergence 6 x 10 - 5 rad obtained by double successive diffraction in the (n 1 , +n 2 ) setting was used. This scheme enables diffraction focusing of a weakly absorbed wave field onto the exit surface of the crystal to be performed. Topographs of a wedge-shaped silicon crystal were obtained. Interference effects such as focusing, anomalous and ordinary Pendelloesung effects peculiar to X-ray spherical wave diffraction were observed in the topographs with high resolution. (author)

Association of UV radiation with Parkinson disease incidence: A nationwide French ecologic study

Energy Technology Data Exchange (ETDEWEB)

Kravietz, Adam [University of Miami Miller School of Medicine, Miami, Florida (United States); Kab, Sofiane [Santé publique France, Direction santé travail, F-94415 Saint-Maurice (France); CESP, Fac. de médecine - Univ. Paris-Sud, Fac. de médecine - UVSQ, INSERM, Université Paris-Saclay, 94805 Villejuif (France); Wald, Lucien [MINES ParisTech, PSL Research University, Sophia Antipolis (France); Dugravot, Aline [CESP, Fac. de médecine - Univ. Paris-Sud, Fac. de médecine - UVSQ, INSERM, Université Paris-Saclay, 94805 Villejuif (France); Singh-Manoux, Archana [CESP, Fac. de médecine - Univ. Paris-Sud, Fac. de médecine - UVSQ, INSERM, Université Paris-Saclay, 94805 Villejuif (France); Department of Epidemiology and Public Health, University College London, London (United Kingdom); Moisan, Frédéric [Santé publique France, Direction santé travail, F-94415 Saint-Maurice (France); Elbaz, Alexis, E-mail: alexis.elbaz@inserm.fr [Santé publique France, Direction santé travail, F-94415 Saint-Maurice (France); CESP, Fac. de médecine - Univ. Paris-Sud, Fac. de médecine - UVSQ, INSERM, Université Paris-Saclay, 94805 Villejuif (France)

2017-04-15

Background: Vitamin D is thought to contribute to brain health, but it is unclear whether low vitamin D levels are associated with increased incidence of Parkinson's disease (PD). Using ultraviolet B (UV-B) as a surrogate for vitamin D levels, we conducted a nationwide ecologic study in France in order to examine the association of UV-B with PD incidence. Methods: We used French national drug claims databases to identify PD cases using a validated algorithm. UV-B data from the solar radiation database were derived from satellite images. We estimated PD incidence (2010–2012) at the canton level (small administrative French unit) and used multilevel Poisson regression to examine its association with UV-B (2005 annual average), after adjustment for age, sex, deprivation index, density of neurologists, smoking, proportion of agricultural land, and vitamin D supplementation. Results: Analyses are based on 69,010 incident PD patients. The association between UV-B and PD incidence was quadratic (P<0.001) and modified by age (P<0.001). Below 70y, incidence was higher in the bottom quintile (relative risk, RR{sub Q1:45-49y}=1.18, 95% CI=1.08–1.29) compared with the middle UV-B quintile, and lower in the top quintile (RR{sub Q5:45-49y}=0.85 [0.77–0.94]). An opposite pattern was observed in older subjects (RR{sub Q1:85-89y}=0.92 [0.89–0.96]; RR{sub Q5:85-89y}=1.06 [1.02–1.11]). Analysis based on continuous UV-B yielded similar conclusions. Conclusions: In this nationwide study, there was an age-dependent quadratic association between UV-B and PD incidence. This study suggests that reasonable UV-B exposure is associated with lower PD risk in younger persons and that future studies should examine dose-response relations and take age into account. - Highlights: • There is an age-dependent quadratic association between UV-B and PD incidence. • Reasonable UV-B exposure is beneficial in younger persons for the risk of PD. • Our findings are consistent with a

Variation in yield ratios of fragment ions and of ion-pairs from CF2Cl2 following monochromatic soft X-ray absorption

International Nuclear Information System (INIS)

Suzuki, I.H.; Saito, N.; Bozek, J.D.

1995-01-01

Fragment ions produced from CF 2 Cl 2 have been measured from 44 to 1200eV using a time-of-flight mass spectrometer and monochromatized synchrotron radiation. Positively charged ion pairs from this molecule were observed in the inner-shell excitation regions using a Selected photoion-photoion coincidence technique. Obtained yield ratios of fragment ions indicate that the atomic chlorine ion, Cl + , has the greatest intensity at all photon energies above 60eV and exhibits a steep increase at the Cl L 2,3 -edges. Some fragment ions, in particular CF 2 + , have a clear intensity increase at the transitions of inner-shell electrons to unoccupied molecular orbitals. The ion pair F + - Cl + exhibits the highest yield at most photon energies, and some of the branching ratios for ion-pair production changed significantly near the Cl L 2,3 -edges. (author)

Lessons Learnt from Past Incidents and Accidents in Radiation Oncology.

Science.gov (United States)

Knöös, T

2017-09-01

The purpose of this report is to review and compile what have been and can be learnt from incidents and accidents in radiation oncology, especially in external beam and brachytherapy. Some major accidents from the last 20 years will be discussed. The relationship between major events and minor or so-called near misses is mentioned, leading to the next topic of exploring the knowledge hidden among them. The main lessons learnt from the discussion here and elsewhere are that a well-functioning and safe radiotherapy department should help staff to work with awareness and alertness and that documentation and procedures should be in place and known by everyone. It also requires that trained and educated staff with the required competences are in place and, finally, functions and responsibilities are defined and well known. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Effects of the chromatic defocus caused by interchange of two monochromatic lights on refraction and ocular dimension in guinea pigs.

Science.gov (United States)

Qian, Yi-Feng; Dai, Jin-Hui; Liu, Rui; Chen, Min-Jie; Zhou, Xing-Tao; Chu, Ren-Yuan

2013-01-01

To investigate refractive and axial responses to the shift of focal plane resulting from the interchange of two monochromatic lights separately corresponding to the peak wavelengths of the cones absorption spectrum in retina, fifty 2-week-old pigmented guinea pigs were randomly assigned to five groups based on the mode of illumination: short-wavelength light (SL), middle-wavelength light (ML) and broad-band white light (BL) for 20 weeks, SL for 10 weeks followed by ML for 10 weeks (STM), as well as ML for 10 weeks followed by SL for 10 weeks (MTS). Biometric and refractive measurements were then performed every 2 weeks. After 10 weeks, SL and STM groups became more hyperopic and had less vitreous elongation than BL group. However, ML and MTS groups became more myopic and had more vitreous elongation. After interchange of the monochromatic light, the refractive error decreased rapidly by about 1.93D and the vitreous length increased by 0.14 mm in STM group from 10 to 12 weeks. After that, there were no significant intergroup differences between STM and BL groups. The interchange from ML to SL quickly increased the refractive error by about 1.53D and decreased the vitreous length by about 0.13 mm in MTS group after two weeks. At this time, there were also no significant intergroup differences between MTS and BL groups. The guinea pig eye can accurately detect the shift in focal plane caused by interchange of two monochromatic lights and rapidly generate refractive and axial responses. However, an excessive compensation was induced. Some properties of photoreceptors or retina may be changed by the monochromatic light to influence the following refractive development.

SU-E-T-208: Incidence Cancer Risk From the Radiation Treatment for Acoustic Neuroma Patient

Energy Technology Data Exchange (ETDEWEB)

Kim, D [Kyung Hee University International Med. Serv., Seoul (Korea, Republic of); Chung, W [Kyung Hee University Hospital at Gangdong, Seoul, Seoul (Korea, Republic of); Shin, D [Kyung Hee University Hospital, Seoul, Seoul (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

2014-06-01

Purpose: The present study aimed to compare the incidence risk of a secondary cancer from therapeutic doses in patients receiving intensitymodulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Methods: Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their incidnece excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) were estimated using the corresponding therapeutic doses measured at various organs by radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. Results: When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, normal liver, colon, bladder, prostate (or ovary), and rectum were measured. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A LAR were estimated that more than 0.03% of AN patients would get radiation-induced cancer. Conclusion: The tyroid was highest radiation-induced cancer risk after radiation treatment for AN. We found that LAR can be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

The incidence of breast cancer following mantle field radiation therapy as a function of dose and technique

International Nuclear Information System (INIS)

Tinger, Alfred; Wasserman, Todd H.; Klein, Eric E.; Miller, Elizabeth A.; Roberts, Tracy; Piephoff, James V.; Kucik, Nancy A.

1997-01-01

Purpose: There is an increased incidence of breast cancer following mantle field radiation therapy for Hodgkin's disease (HD). We reviewed the experience at the Mallinckrodt Institute of Radiology (MIR) for radiation factors related to the development of breast cancer after mantle field radiation therapy for HD. Methods: The radiation therapy records of 152 women treated with mantle field irradiation for HD at MIR between 1966-1985 were reviewed for the development of breast cancer and treatment-related factors. All patients had a minimum of 5 years of follow-up. The treatment era (1966-1974 vs. 1975-1985), stage of HD, mediastinal dose, axillary dose, maximum dose from the anterior field (anterior d max dose), the anterior-posterior:posterior-anterior (AP:PA) ratio, age at the time of treatment, length of follow-up, and history of splenectomy were analyzed as possible contributing factors for the development of breast cancer. The observed number of breast cancers was compared to the expected number based on age-adjusted incidences from the Connecticut Tumor Registry. Results: Ten breast cancers occurred in the population. Eight involved an upper outer quadrant. In a multivariate analysis, the development of breast cancer was significantly associated with axillary dose. Patients in the early treatment era were at an increased risk for the development of breast cancer due to high anterior d max and breast doses from weighting the fields anteriorly on a low energy linear accelerator. The use of current radiation therapy techniques was not related to an increased risk of breast cancer with a median follow-up of 13 years. Conclusions: A high dose to the axilla and the anterior d max point is significantly associated with the development of breast cancer after mantle field irradiation for HD. Efforts to protect the breast from high doses will likely lessen the increased risk of breast cancer in women treated with radiation therapy for HD

Study of electron densities of normal and neoplastic human breast tissues by Compton scattering using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Antoniassi, M.; Conceicao, A.L.C. [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto-Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil); Poletti, M.E., E-mail: poletti@ffclrp.usp.br [Departamento de Fisica-Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto-Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo (Brazil)

2012-07-15

Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a monochromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%. - Highlights: Black-Right-Pointing-Pointer Electron density of normal and neoplastic breast tissues was measured using Compton scattering. Black-Right-Pointing-Pointer Monochromatic synchrotron radiation was used to obtain the Compton scattering data. Black-Right-Pointing-Pointer The area of Compton peaks was used to determine the electron densities of samples. Black-Right-Pointing-Pointer Adipose tissue shows the lowest electron density values whereas the malignant tissue the highest. Black-Right-Pointing-Pointer Comparison with previous results showed differences smaller than 4%.

Study of electron densities of normal and neoplastic human breast tissues by Compton scattering using synchrotron radiation

International Nuclear Information System (INIS)

Antoniassi, M.; Conceição, A.L.C.; Poletti, M.E.

2012-01-01

Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a monochromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%. - Highlights: ► Electron density of normal and neoplastic breast tissues was measured using Compton scattering. ► Monochromatic synchrotron radiation was used to obtain the Compton scattering data. ► The area of Compton peaks was used to determine the electron densities of samples. ► Adipose tissue shows the lowest electron density values whereas the malignant tissue the highest. ► Comparison with previous results showed differences smaller than 4%.

Observation of Intravascular Changes of Superabsorbent Polymer Microsphere (SAP-MS) with Monochromatic X-Ray Imaging

International Nuclear Information System (INIS)

Tanimoto, Daigo; Ito, Katsuyoshi; Yamamoto, Akira; Sone, Teruki; Kobatake, Makito; Tamada, Tsutomu; Umetani, Keiji

2010-01-01

This study was designed to evaluate the intravascular transformation behavior of superabsorbent polymer microsphere (SAP-MS) in vivo macroscopically by using monochromatic X-ray imaging and to quantitatively compare the expansion rate of SAP-MS among different kinds of mixtures. Fifteen rabbits were used for our study and transcatheter arterial embolization (TAE) was performed for their auricular arteries using monochromatic X-ray imaging. We used three kinds of SAP-MS (particle diameter 100-150 μm) mixture as embolic spherical particles: SAP-MS(H) absorbed with sodium meglumine ioxaglate (Hexabrix 320), SAP-MS(V) absorbed with isosmolar contrast medium (Visipaque 270), and SAP-MS(S) absorbed with 0.9% sodium saline. The initial volume of SAP-MS particles just after TAE and its final volume 10 minutes after TAE in the vessel were measured to calculate the expansion rate (ER) (n = 30). Intravascular behavior of SAP-MS particles was clearly observed in real time at monochromatic X-ray imaging. Averaged initial volumes of SAP-MS (H) (1.24 x 10 7 μm 3 ) were significantly smaller (p 7 μm 3 ) and SAP-MS (S) (5.85 x 10 7 μm 3 ). Averaged final volumes of SAP-MS (H) were significantly larger than averaged initial volumes (4.41 x 10 7 μm 3 vs. 1.24 x 10 7 μm 3 ; p < 0.0001, ER = 3.55). There were no significant difference between averaged final volumes and averaged initial volumes of SAP-MS (V) and SAP-MS (S). SAP-MS (H), which first travels distally, reaches to small arteries, and then expands to adapt to the vessel lumen, is an effective particle as an embolic agent, causing effective embolization.

Dependence of laser radiation intensity on the elastic deformation of a revolving optical disk with a reflective coating

Science.gov (United States)

Gladyshev, V. O.; Portnov, D. I.

2016-12-01

The physical mechanism of alteration of intensity of linearly polarized monochromatic electromagnetic radiation with λ = 630 nm in a revolving dielectric disk with a mirror coating is examined. The effect is induced by elastic deformation due to the revolution and by thermoelastic deformation of the optically transparent disk. These deformations result in birefringence, the polarization plane rotation, and a 30-40% change in the intensity of reflected radiation.

New sub-Doppler absorption resonances in a thin gas cell produced by means of a running monochromatic wave

International Nuclear Information System (INIS)

Tajalli, H; Ahmadi, S; Izmailov, A Ch

2002-01-01

A theoretical investigation is carried out through the interaction of the plane running monochromatic light wave, having an arbitrary intensity, with atoms (molecules) of a rarefied gas in the plane cell (at the normal incidence of the wave). Cases of closed and open resonance transitions from the non-degenerate ground (or metastable) quantum level are considered. Possible sub-Doppler resonances are analysed in the wave absorption, caused by the transient establishment of the optical coherence on the transition, Rabi oscillations between its levels, and optical pumping during the free flights of particles between the walls of the cell. Results of the previous works on given problems are generalized, which were obtained at definite restrictions on the wave intensity and cell length. Moreover, non-trivial sub-Doppler spectral structures, resulting as a consequence of the dependence of the absorption saturation on the transit relaxation of particles, have been established and investigated. Such structures may consist of a number of peaks and dips caused by Rabi oscillations between the transition levels. The results obtained can be used in sub-Doppler spectroscopy and for the stabilization of laser frequencies in thin gas cells

Radiation-shielded double crystal X-ray monochromator for JET

International Nuclear Information System (INIS)

Barnsley, R.; Morsi, H.W.; Rupprecht, G.; Kaellne, E.

1989-01-01

A double crystal X-ray monochromator for absolute wavelength and intensity measurements with very effective shielding of its detector against neutrons and hard X-rays was brought into operation at JET. Fast wavelength scans were taken of impurity line radiation in the wavelength region from about 0.1 nm to 2.3 nm, and monochromatic as well as spectral line scans, for different operational modes of JET. (author) 5 refs., 4 figs

Incidence of and factors related to late complications in conformal and conventional radiation treatment of cancer of the prostate

Energy Technology Data Exchange (ETDEWEB)

Schultheiss, Timothy E; Hanks, Gerald E; Hunt, Margie A; Lee, W Robert

1995-06-15

Purpose: The fundament hypothesis of conformal radiation therapy is that tumor control can be increased by using conformal treatment techniques that allow a higher tumor dose while maintaining an acceptable level of complications. To test this hypothesis, it is necessary first to estimate the incidence of morbidity for both standard and conformal fields. In this study, we examine factors that influence the incidence of late Grade 3 and 4 morbidity in patients treated with conformal and standard radiation treatment for prostate cancer. Methods and Materials: Six hundred sixteen consecutive patients treated with conformal or standard techniques between 1986 and 1994 to doses greater than 65 Gy and with more than 3 months follow-up were analyzed. No patients treated with prostatectomies were included in the analysis. The conformal technique includes special immobilization by a cast, careful identification of the target volume in three dimensions, localization of the inferior border of the prostate using a retrograde urethrogram, and individually shaped portals that conform to the Planning Target Volume (PTV). Multivariate analysis using a proportional hazards model compares differences in the incidence of Radiation Therapy Oncology Group/European Organization for Research and Center Treatment (RTOG/EORTC) Grade 3 and 4 late gastrointestinal (GI) and genitourinary (GU) morbidity by technique, T-stage, grade, age, hormonal treatment, irradiated volume, dose, and comorbid conditions. Grade 3 rectal bleeding was defined as requiring three or more cautery procedures. Results: The overall actuarial incidence of genitourinary (GU) toxicities at 5 years was 3.4%, with the crude incidence being six cases in 616 patients satisfying the selection criteria; for gastrointestinal (GI) toxicities, the overall actuarial incidence was 2.7%, with the crude incidence being 13 cases out of 616 patients. The average time to complication for our patients was 12.8 months for GI toxicity and

Blue cone monochromatism in a female due to skewed X-inactivation

DEFF Research Database (Denmark)

Frederiksen, Anja Lisbeth; Duno, Morten; Welinder, Lotte G

2012-01-01

Blue cone monochromatism (BCM) is a rare cone dystrophy with recessive X-linked inheritance and therefore diagnosed in males whereas females are clinically unaffected. We present a female with clinically manifested BCM. The diagnosis was genetically verified with the identification of one single...... red-green OPN1LW/MW hybrid gene harboring a point mutation c.607C>G, p.Cys203Arg that associates with BCM and in addition a completely biased X-inactivation in DNA isolated from full blood and buccal mucosa. The present case illustrates that females may develop symptoms of recessive X-linked eye...

Incidence of Leukoencephalopathy After Whole-Brain Radiation Therapy for Brain Metastases

International Nuclear Information System (INIS)

Ebi, Junko; Sato, Hisashi; Nakajima, Masaru; Shishido, Fumio

2013-01-01

Purpose: To evaluate the incidence of leukoencephalopathy after whole-brain radiation therapy (WBRT) in patients with brain metastases. Methods and Materials: We retrospectively reviewed 111 patients who underwent WBRT for brain metastases from April 2001 through March 2008 and had evaluable computed tomography (CT) and/or magnetic resonance imaging (MRI) at least 1 month after completion of WBRT. We evaluated the leukoencephalopathy according to the Common Terminology Criteria for Adverse Events, version 3.0. The patients who had brain tumor recurrence after WBRT were censored at the last follow-up CT or MRI without recurrence. To evaluate the risk factors for leukoencephalopathy, bivariate analysis was performed using a logistic regression analysis adjusted for follow-up time. Factors included in the analysis were age, gender, dose fractionation, 5-fluorouracil, methotrexate, cisplatin, and other chemotherapeutic agents. Results: The median age of the 111 patients was 60.0 years (range, 23-89 years). The median follow-up was 3.8 months (range, 1.0-38.1 months). Leukoencephalopathy developed in 23 of the 111 patients. Grades 1, 2, and 3 were observed in 8, 7, and 8 patients, respectively. The incidence was 34.4% (11 of 32), 42.9% (6 of 14), 66.7% (2 of 3), and 100% (2 of 2) of the patients who were followed up for ≥6, ≥12, ≥24, and ≥36 months, respectively. In the bivariate analysis, older age (≥65 years) was significantly correlated with higher risk of leukoencephalopathy (odds ratio 3.31; 95% confidence interval 1.15-9.50; P=.03). Conclusions: The incidence of leukoencephalopathy after WBRT was 34.4% with ≥6 months follow-up, and increased with longer follow-up. Older age was a significant risk factor. The schedule of WBRT for patients with brain metastases should be carefully determined, especially for favorable patients

Incidence, Causative Mechanisms, and Anatomic Localization of Stroke in Pituitary Adenoma Patients Treated With Postoperative Radiation Therapy Versus Surgery Alone

Energy Technology Data Exchange (ETDEWEB)

Sattler, Margriet G.A., E-mail: g.a.sattler@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Vroomen, Patrick C. [Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Sluiter, Wim J. [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Schers, Henk J. [Department of Primary and Community Care, Radboud University Nijmegen Medical Centre (Netherlands); Berg, Gerrit van den [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Bergh, Alphons C.M. van den [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Beek, André P. van [Department of Endocrinology and Metabolic Diseases, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

2013-09-01

Purpose: To assess and compare the incidence of stroke and stroke subtype in pituitary adenoma patients treated with postoperative radiation therapy (RT) and surgery alone. Methods and Materials: A cohort of 462 pituitary adenoma patients treated between 1959 and 2008 at the University Medical Center Groningen in The Netherlands was studied. Radiation therapy was administered in 236 patients. The TOAST (Trial of ORG 10172 in Acute Stroke Treatment) and the Oxfordshire Community Stroke Project classification methods were used to determine causative mechanism and anatomic localization of stroke. Stroke incidences in patients treated with RT were compared with that observed after surgery alone. Risk factors for stroke incidence were studied by log–rank test, without and with stratification for other significant risk factors. In addition, the stroke incidence was compared with the incidence rate in the general Dutch population. Results: Thirteen RT patients were diagnosed with stroke, compared with 12 surgery-alone patients. The relative risk (RR) for stroke in patients treated with postoperative RT was not significantly different compared with surgery-alone patients (univariate RR 0.62, 95% confidence interval [CI] 0.28-1.35, P=.23). Stroke risk factors were coronary or peripheral artery disease (univariate and multivariate RR 10.4, 95% CI 4.7-22.8, P<.001) and hypertension (univariate RR 3.9, 95% CI 1.6-9.8, P=.002). There was no difference in TOAST and Oxfordshire classification of stroke. In this pituitary adenoma cohort 25 strokes were observed, compared with 16.91 expected (standard incidence ratio 1.48, 95% CI 1.00-1.96, P=.049). Conclusions: In pituitary adenoma patients, an increased incidence of stroke was observed compared with the general population. However, postoperative RT was not associated with an increased incidence of stroke or differences in causative mechanism or anatomic localization of stroke compared with surgery alone. The primary stroke risk

Incidence, Causative Mechanisms, and Anatomic Localization of Stroke in Pituitary Adenoma Patients Treated With Postoperative Radiation Therapy Versus Surgery Alone

International Nuclear Information System (INIS)

Sattler, Margriet G.A.; Vroomen, Patrick C.; Sluiter, Wim J.; Schers, Henk J.; Berg, Gerrit van den; Langendijk, Johannes A.; Wolffenbuttel, Bruce H.R.; Bergh, Alphons C.M. van den; Beek, André P. van

2013-01-01

Purpose: To assess and compare the incidence of stroke and stroke subtype in pituitary adenoma patients treated with postoperative radiation therapy (RT) and surgery alone. Methods and Materials: A cohort of 462 pituitary adenoma patients treated between 1959 and 2008 at the University Medical Center Groningen in The Netherlands was studied. Radiation therapy was administered in 236 patients. The TOAST (Trial of ORG 10172 in Acute Stroke Treatment) and the Oxfordshire Community Stroke Project classification methods were used to determine causative mechanism and anatomic localization of stroke. Stroke incidences in patients treated with RT were compared with that observed after surgery alone. Risk factors for stroke incidence were studied by log–rank test, without and with stratification for other significant risk factors. In addition, the stroke incidence was compared with the incidence rate in the general Dutch population. Results: Thirteen RT patients were diagnosed with stroke, compared with 12 surgery-alone patients. The relative risk (RR) for stroke in patients treated with postoperative RT was not significantly different compared with surgery-alone patients (univariate RR 0.62, 95% confidence interval [CI] 0.28-1.35, P=.23). Stroke risk factors were coronary or peripheral artery disease (univariate and multivariate RR 10.4, 95% CI 4.7-22.8, P<.001) and hypertension (univariate RR 3.9, 95% CI 1.6-9.8, P=.002). There was no difference in TOAST and Oxfordshire classification of stroke. In this pituitary adenoma cohort 25 strokes were observed, compared with 16.91 expected (standard incidence ratio 1.48, 95% CI 1.00-1.96, P=.049). Conclusions: In pituitary adenoma patients, an increased incidence of stroke was observed compared with the general population. However, postoperative RT was not associated with an increased incidence of stroke or differences in causative mechanism or anatomic localization of stroke compared with surgery alone. The primary stroke risk

Unusual reflection of electromagnetic radiation from a stack of graphene layers at oblique incidence

International Nuclear Information System (INIS)

Bludov, Yu V; Peres, N M R; Vasilevskiy, M I

2013-01-01

We study the interaction of electromagnetic (EM) radiation with single-layer graphene and a stack of parallel graphene sheets at arbitrary angles of incidence. It is found that the behavior is qualitatively different for transverse magnetic (or p-polarized) and transverse electric (or s-polarized) waves. In particular, the absorbance of single-layer graphene attains a minimum (maximum) for the p (s)-polarization at the angle of total internal reflection when the light comes from a medium with a higher dielectric constant. In the case of equal dielectric constants of the media above and beneath graphene, for grazing incidence graphene is almost 100% transparent to p-polarized waves and acts as a tunable mirror for the s-polarization. These effects are enhanced for a stack of graphene sheets, so the system can work as a broad band polarizer. It is shown further that a periodic stack of graphene layers has the properties of a one-dimensional photonic crystal, with gaps (or stop bands) at certain frequencies. When an incident EM wave is reflected from this photonic crystal, the tunability of the graphene conductivity renders the possibility of controlling the gaps, and the structure can operate as a tunable spectral-selective mirror. (paper)

Role of radiation therapy in the management of plasma cell tumors. [Incidence of complications

Energy Technology Data Exchange (ETDEWEB)

Mill, W.B.; Griffith, R.

1980-02-15

A retrospective review is reported of 128 patients presenting with multiple myeloma and 16 patients presenting with solitary plasmacytoma. Ninety-one percent of 116 evaluable patients treated for palliation of painful bone disease received some degree of subjective pain relief. The radiation dose most frequently prescribed was between 1500 and 2000 rad. Of the 278 ports treated, only 17 (6.1%) were re-treated to the same area at a later date. There was no increase in incidence of re-treatment with lower radiation doses. Ten of the 13 patients treated for a solitary plasmacytoma with a minimum follow-up period of three years have local tumor control. The median survival in the solitary plasmacytomas is five and one-half years. Data from the literature on 27 additional solitary plasmacytomas combined with our data suggest an improved local control and a decrease in dissemination with doses greater than 5000 rad. It is concluded that low doses of radiation are usually adequate to treat painful bone lesions of multiple myeloma and doses of 5000 to 6500 rad in six to seven weeks are recommended for solitary plasmacytomas.

Effects of the chromatic defocus caused by interchange of two monochromatic lights on refraction and ocular dimension in guinea pigs.

Directory of Open Access Journals (Sweden)

Yi-Feng Qian

Full Text Available To investigate refractive and axial responses to the shift of focal plane resulting from the interchange of two monochromatic lights separately corresponding to the peak wavelengths of the cones absorption spectrum in retina, fifty 2-week-old pigmented guinea pigs were randomly assigned to five groups based on the mode of illumination: short-wavelength light (SL, middle-wavelength light (ML and broad-band white light (BL for 20 weeks, SL for 10 weeks followed by ML for 10 weeks (STM, as well as ML for 10 weeks followed by SL for 10 weeks (MTS. Biometric and refractive measurements were then performed every 2 weeks. After 10 weeks, SL and STM groups became more hyperopic and had less vitreous elongation than BL group. However, ML and MTS groups became more myopic and had more vitreous elongation. After interchange of the monochromatic light, the refractive error decreased rapidly by about 1.93D and the vitreous length increased by 0.14 mm in STM group from 10 to 12 weeks. After that, there were no significant intergroup differences between STM and BL groups. The interchange from ML to SL quickly increased the refractive error by about 1.53D and decreased the vitreous length by about 0.13 mm in MTS group after two weeks. At this time, there were also no significant intergroup differences between MTS and BL groups. The guinea pig eye can accurately detect the shift in focal plane caused by interchange of two monochromatic lights and rapidly generate refractive and axial responses. However, an excessive compensation was induced. Some properties of photoreceptors or retina may be changed by the monochromatic light to influence the following refractive development.

TU-D-201-04: Veracity of Data Elements in Radiation Oncology Incident Learning Systems

International Nuclear Information System (INIS)

Kapur, A; Evans, S; Brown, D; Ezzell, G; Hoopes, D; Dieterich, S; Kapetanovic, K; Tomlinson, C

2016-01-01

Purpose: Incident learning systems encompass volumes, varieties, values, and velocities of underlying data elements consistent with the V’s of big data. Veracity, the 5th V however exists only if there is high inter-rater reliability (IRR) within the data elements. The purpose of this work was to assess IRR in the nationally deployed RO-ILS: Radiation Oncology-Incident Learning System (R) sponsored by the American Society for Radiation Oncology (ASTRO) and the American Association of Physicists in Medicine (AAPM). Methods: Ten incident reports covering a wide range of scenarios were created in standardized narrative and video formats and disseminated to 67 volunteers of multiple disciplines from 26 institutions along with two published narratives from the International Commission of Radiological Protection to assess IRR on a nationally representative level. The volunteers were instructed to independently enter the associated data elements in a test version of RO-ILS over a 3-week period. All responses were aggregated into a spreadsheet to assess IRR using free-marginal kappa metrics. Results: 48 volunteers from 21 institutions completed all reports in the study period. The average kappa score for all raters across all critical data elements was 0.659 [range 0.326–1.000]. Statistically significant differences (p <0.05) were noted between reporters of different disciplines and raters with varying levels of experience. Kappa scores were high for event classification (0.781) and contributory factors (0.777) and low for likelihood-of-harm (0.326). IRR was highest among AAPM-ASTRO members (0.672) and lowest among trainees (0.463). Conclusion: A moderate-to-substantial level of IRR in RO-ILS was noted in this study. Although the number of events reviewed in this study was small, opportunities for improving the taxonomy for the lower scoring data elements as well as specific educational targets for training were identified by assessing data veracity quantitatively

TU-D-201-04: Veracity of Data Elements in Radiation Oncology Incident Learning Systems

Energy Technology Data Exchange (ETDEWEB)

Kapur, A [Northwell Health System, New Hyde Park, NY (United States); Evans, S [Yale University New Haven, CT (United States); Brown, D [University of California, San Diego, La Jolla, CA (United States); Ezzell, G [Mayo Clinic Arizona, Phoenix, AZ (United States); Hoopes, D [The University of California San Diego, San Diego, CA (United States); Dieterich, S [UC Davis Medical Center, Sacramento, CA (United States); Kapetanovic, K; Tomlinson, C [American Society for Radiation Oncology, Fairfax, VA (United States)

2016-06-15

Purpose: Incident learning systems encompass volumes, varieties, values, and velocities of underlying data elements consistent with the V’s of big data. Veracity, the 5th V however exists only if there is high inter-rater reliability (IRR) within the data elements. The purpose of this work was to assess IRR in the nationally deployed RO-ILS: Radiation Oncology-Incident Learning System (R) sponsored by the American Society for Radiation Oncology (ASTRO) and the American Association of Physicists in Medicine (AAPM). Methods: Ten incident reports covering a wide range of scenarios were created in standardized narrative and video formats and disseminated to 67 volunteers of multiple disciplines from 26 institutions along with two published narratives from the International Commission of Radiological Protection to assess IRR on a nationally representative level. The volunteers were instructed to independently enter the associated data elements in a test version of RO-ILS over a 3-week period. All responses were aggregated into a spreadsheet to assess IRR using free-marginal kappa metrics. Results: 48 volunteers from 21 institutions completed all reports in the study period. The average kappa score for all raters across all critical data elements was 0.659 [range 0.326–1.000]. Statistically significant differences (p <0.05) were noted between reporters of different disciplines and raters with varying levels of experience. Kappa scores were high for event classification (0.781) and contributory factors (0.777) and low for likelihood-of-harm (0.326). IRR was highest among AAPM-ASTRO members (0.672) and lowest among trainees (0.463). Conclusion: A moderate-to-substantial level of IRR in RO-ILS was noted in this study. Although the number of events reviewed in this study was small, opportunities for improving the taxonomy for the lower scoring data elements as well as specific educational targets for training were identified by assessing data veracity quantitatively

Exergy of partially coherent thermal radiation

International Nuclear Information System (INIS)

Wijewardane, S.; Goswami, Yogi

2012-01-01

Exergy of electromagnetic radiation has been studied by a number of researchers for well over four decades in order to estimate the maximum conversion efficiencies of thermal radiation. As these researchers primarily dealt with solar and blackbody radiation, which have a low degree of coherence, they did not consider the partial coherence properties of thermal radiation. With the recent development of surface structures, which can emit radiation with high degree of coherence, the importance of considering the partial coherent properties in exergy calculation has become a necessity as the coherence properties directly influence the entropy of the wave field. Here in this paper we derive an expression for the exergy of quasi-monochromatic radiation using statistical thermodynamics and show that it is identical with the expressions derived using classical thermodynamics. We also present a method to calculate the entropy, thereby the exergy of partially coherent radiation using statistical thermodynamics and a method called matrix treatment of wave field. -- Highlights: ► Considered partial coherence of radiation for the first time to calculate exergy. ► The importance of this method is emphasized with energy conversion examples. ► Derived an expression for the exergy of radiation using statistical thermodynamics. ► Adopted a method to calculate intensity of statistically independent principle wave.

Compton scattering and γ-quanta monochromatization

International Nuclear Information System (INIS)

Goryachev, B.I.; Shevchenko, V.G.

1979-01-01

The γ-quanta monochromatization method is proposed for sdudying high-excited states and mechanisms of nuclei photodisintegration. The method is based on the properties of photon Compton scattering. It permits to obtain high energy resolution without accurate analysis of the particle energies taking part in the scattering process. A possible design of the compton γ- monochromator is presented. The γ-quanta scatterer of the elements with a small nucleus charge (e.g. LiH) is placed inside the β-spectrometer of low resolution. The monochromator is expected to operate in the γ-beam of the high-current synchrotron, and it provides for a rather good energy resolution rho(W) while studying the high-excited nucleus states (rho(W) approximately 2% in the range of the giant dipole resonance). With the γ-quanta energy growth rho(W) increases as Wsup(0.6). The monochromator permits to obtain high statistical accuracy for a smaller period of time (at a considerably better energy resolution) than while working with a bremsstrahlung spectrum. The yield of quasimonochromatic photons related to the ΔW(ΔW = rho(W)W) range of energy resolution increases as Wsup(0.6). This fact makes it promjssing to use monochromator in the energy range considerably exceeding the characteristic energy of the gigantic dipole resonance

Radiological incidents in radiotherapy

International Nuclear Information System (INIS)

Hobzova, L.; Novotny, J.

2008-01-01

In many countries a reporting system of radiological incidents to national regulatory body exists and providers of radiotherapy treatment are obliged to report all major and/or in some countries all incidents occurring in institution. State Office for Nuclear Safety (SONS) is providing a systematic guidance for radiotherapy departments from 1997 by requiring inclusion of radiation safety problems into Quality assurance manual, which is the basic document for obtaining a license of SONS for handling with sources of ionizing radiation. For that purpose SONS also issued the recommendation 'Introduction of QA system for important sources in radiotherapy-radiological incidents' in which the radiological incidents are defined and the basic guidance for their classification (category A, B, C, D), investigation and reporting are given. At regular periods the SONS in co-operation with radiotherapy centers is making a survey of all radiological incidents occurring in institutions and it is presenting obtained information in synoptic communication (2003 Motolske dny, 2005 Novy Jicin). This presentation is another summary report of radiological incidents that occurred in our radiotherapy institutions during last 3 years. Emphasis is given not only to survey and statistics, but also to analysis of reasons of the radiological incidents and to their detection and prevention. Analyses of incidents in radiotherapy have led to a much broader understanding of incident causation. Information about the error should be shared as early as possible during or after investigation by all radiotherapy centers. Learning from incidents, errors and near misses should be a part of improvement of the QA system in institutions. Generally, it is recommended that all radiotherapy facilities should participate in the reporting, analyzing and learning system to facilitate the dissemination of knowledge throughout the whole country to prevent errors in radiotherapy.(authors)

Assessment of radiation doses due to normal operation, incidents and accidents of the final disposal facility

International Nuclear Information System (INIS)

Rossi, J.; Raiko, H.; Suolanen, V.; Ilvonen, M.

1999-03-01

Radiation doses for workers of the encapsulation and disposal facility and for inhabitants in the environment caused by the facility during its operation were considered. The study covers both the normal operation of the plant and some hypothetical incidents and accidents. Occupational radiation doses inside the plant during normal operation are based on the design basis, assuming that highest permitted dose levels are prevailing in control rooms during fuel transfer and encapsulation processes. Release through the ventilation stack is assumed to be filtered both in normal operation and in hypothetical incident and accident cases. Calculation of the offsite doses from normal operation is based on the hypothesis that one fuel pin per 100 fuel bundles for all batches of spent fuel transported to the encapsulation facility is leaking. The release magnitude in incidents and accidents is based on the event chains, which lead to loss of fuel pin tightness followed by a discharge of radionuclides into the handling chamber and to some degree through the ventilation stack into atmosphere. The weather data measured at the Olkiluoto meteorological mast was employed for calculating of offsite doses. Therefore doses could be calculated in a large amount of different dispersion conditions, the statistical frequencies of which have, been measured. Finally doses were combined into cumulative distributions, from which a dose value representing the 99.5 % confidence level, is presented. The dose values represent the exposure of a critical group, which is assumed to live at the distance of 200 meters from the encapsulation and disposal plant and thus it will receive the largest doses in most dispersion conditions. Exposure pathways considered were: cloudsnine, inhalation, groundshine and nutrition (milk of cow, meat of cow, green vegetables, grain and root vegetables). Nordic seasonal variation is included in ingestion dose models. The results obtained indicate that offsite doses

Monte Carlo mixture model of lifetime cancer incidence risk from radiation exposure on shuttle and international space station

International Nuclear Information System (INIS)

Peterson, L.E.; Cucinotta, F.A.

1999-01-01

Estimating uncertainty in lifetime cancer risk for human exposure to space radiation is a unique challenge. Conventional risk assessment with low-linear-energy-transfer (LET)-based risk from Japanese atomic bomb survivor studies may be inappropriate for relativistic protons and nuclei in space due to track structure effects. This paper develops a Monte Carlo mixture model (MCMM) for transferring additive, National Institutes of Health multiplicative, and multiplicative excess cancer incidence risks based on Japanese atomic bomb survivor data to determine excess incidence risk for various US astronaut exposure profiles. The MCMM serves as an anchor point for future risk projection methods involving biophysical models of DNA damage from space radiation. Lifetime incidence risks of radiation-induced cancer for the MCMM based on low-LET Japanese data for nonleukemia (all cancers except leukemia) were 2.77 (90% confidence limit, 0.75-11.34) for males exposed to 1 Sv at age 45 and 2.20 (90% confidence limit, 0.59-10.12) for males exposed at age 55. For females, mixture model risks for nonleukemia exposed separately to 1 Sv at ages of 45 and 55 were 2.98 (90% confidence limit, 0.90-11.70) and 2.44 (90% confidence limit, 0.70-10.30), respectively. Risks for high-LET 200 MeV protons (LET=0.45 keV/μm), 1 MeV α-particles (LET=100 keV/μm), and 600 MeV iron particles (LET=180 keV/μm) were scored on a per particle basis by determining the particle fluence required for an average of one particle per cell nucleus of area 100 μm 2 . Lifetime risk per proton was 2.68x10 -2 % (90% confidence limit, 0.79x10 -3 %-0.514x10 -2 %). For α-particles, lifetime risk was 14.2% (90% confidence limit, 2.5%-31.2%). Conversely, lifetime risk per iron particle was 23.7% (90% confidence limit, 4.5%-53.0%). Uncertainty in the DDREF for high-LET particles may be less than that for low-LET radiation because typically there is very little dose-rate dependence. Probability density functions for

Fast and Accurate Hybrid Stream PCRTMSOLAR Radiative Transfer Model for Reflected Solar Spectrum Simulation in the Cloudy Atmosphere

Science.gov (United States)

Yang, Qiguang; Liu, Xu; Wu, Wan; Kizer, Susan; Baize, Rosemary R.

2016-01-01

A hybrid stream PCRTM-SOLAR model has been proposed for fast and accurate radiative transfer simulation. It calculates the reflected solar (RS) radiances with a fast coarse way and then, with the help of a pre-saved matrix, transforms the results to obtain the desired high accurate RS spectrum. The methodology has been demonstrated with the hybrid stream discrete ordinate (HSDO) radiative transfer (RT) model. The HSDO method calculates the monochromatic radiances using a 4-stream discrete ordinate method, where only a small number of monochromatic radiances are simulated with both 4-stream and a larger N-stream (N = 16) discrete ordinate RT algorithm. The accuracy of the obtained channel radiance is comparable to the result from N-stream moderate resolution atmospheric transmission version 5 (MODTRAN5). The root-mean-square errors are usually less than 5x10(exp -4) mW/sq cm/sr/cm. The computational speed is three to four-orders of magnitude faster than the medium speed correlated-k option MODTRAN5. This method is very efficient to simulate thousands of RS spectra under multi-layer clouds/aerosols and solar radiation conditions for climate change study and numerical weather prediction applications.

A parameter quantifying radiation damping of bay oscillations excited by incident tsunamis

Science.gov (United States)

Endoh, Takahiro; Inazu, Daisuke; Waseda, Takuji; Hibiya, Toshiyuki

2018-04-01

The transient response of a bay with a narrow mouth to incident tsunamis is interpreted as the convolution of the input signal with the impulse response obtained by an inverse Fourier transform of the response curve of the oscillatory system with one degree of freedom. The rate of radiation damping associated with energy escaping seaward through the bay mouth is expressed in terms of the quality factor Q, which determines the decaying envelope of the impulse response. The value of Q of the resonant peak is approximated by the ratio of the resonant frequency ω0 to the bandwidth between frequencies at which the power spectral density of sea level within the bay drops to half of the peak value. Since the shape of the frequency power spectrum during the tsunami event is almost similar to that in the normal state in the neighborhood of ω0, Q can be estimated from sea level datasets in the normal state. Although the amplitude and phase of the impulse response need to be adjusted using the first crest or trough of the observed leading wave, this approach proves to work well in examining the transient responses of Miyako Bay and Kushimoto Bay on the Japanese Pacific coast to incident tsunamis.

Entropy flow and generation in radiative transfer between surfaces

Energy Technology Data Exchange (ETDEWEB)

Zhang, Z.M.; Basu, S. [Georgia Institute of Technolgy, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

2007-02-15

Entropy of radiation has been used to derive the laws of blackbody radiation and determine the maximum efficiency of solar energy conversion. Along with the advancement in thermophotovoltaic technologies and nanoscale heat radiation, there is an urgent need to determine the entropy flow and generation in radiative transfer between nonideal surfaces when multiple reflections are significant. This paper investigates entropy flow and generation when incoherent multiple reflections are included, without considering the effects of interference and photon tunneling. The concept of partial equilibrium is applied to interpret the monochromatic radiation temperature of thermal radiation, T{sub l}(l,{omega}), which is dependent on both wavelength l and direction {omega}. The entropy flux and generation can thus be evaluated for nonideal surfaces. It is shown that several approximate expressions found in the literature can result in significant errors in entropy analysis even for diffuse-gray surfaces. The present study advances the thermodynamics of nonequilibrium thermal radiation and will have a significant impact on the future development of thermophotovoltaic and other radiative energy conversion devices. (author)

Radiation injury

International Nuclear Information System (INIS)

Hubner, K.F.

1988-01-01

Radiation accidents and incidents continue to be of great interest and concern to the public. Issues such as the threat of nuclear war, the Chernobyl reactor accident, or reports of sporadic incidences of accidental radiation exposure keep this interest up and maintain a high level of fear among the public. In this climate of real concern and radiation phobia, physicians should not only be prepared to answer questions about acute or late effects of ionizing radiation, but also be able to participate in the initial assessment and management of individuals who have been exposed to ionizing radiation or contaminated with radioactive material. Some of the key facts about radiation injury and its medical treatment are discussed by the author

Contaminated Mexican steel incident

International Nuclear Information System (INIS)

1985-01-01

This report documents the circumstances contributing to the inadvertent melting of cobalt 60 (Co-60) contaminated scrap metal in two Mexican steel foundries and the subsequent distribution of contaminated steel products into the United States. The report addresses mainly those actions taken by US Federal and state agencies to protect the US population from radiation risks associated with the incident. Mexico had much more serious radiation exposure and contamination problems to manage. The United States Government maintained a standing offer to provide technical and medical assistance to the Mexican Government. The report covers the tracing of the source to its origin, response actions to recover radioactive steel in the United States, and return of the contaminated materials to Mexico. The incident resulted in significant radiation exposures within Mexico, but no known significant exposure within the United States. Response to the incident required the combined efforts of the Nuclear Regulatory Commission (NRC), Department of Energy, Department of Transportation, Department of State, and US Customs Service (Department of Treasury) personnel at the Federal level and representatives of all 50 State Radiation Control Programs and, in some instances, local and county government personnel. The response also required a diplomatic interface with the Mexican Government and cooperation of numerous commercial establishments and members of the general public. The report describes the factual information associated with the event and may serve as information for subsequent recommendations and actions by the NRC. 8 figures

Fluorescence-type Monochromatic X-ray Beam-position Monitor with High-spatial Resolution for the NSLS-II Beamlines

International Nuclear Information System (INIS)

Yoon, Phil S.; Siddons, D. Peter

2010-01-01

We developed a fluorescence-type monochromatic X-ray beam-position monitor (X-BPM) with high-spatial resolution for end-station experiments at the initial project beamlines of the NSLS-II. We designed a ring array of multi-segmented Si PIN-junction photodiodes to use as a position sensor. Further, we integrated a low-noise charge-preamplification HERMES4 ASIC chip into an electronic readout system for photon-counting application. A series of precision measurements to characterize electronically the Si-photodiode sensor and the ASIC chip demonstrated that the inherent noise from the detector system is sufficiently low to meet our stringent requirements. Using a Gaussian beam, we parametrically modeled the optimum working distance to ensure the detector's best performance. Based upon the results from the parametric modeling, prototypes of the next versions of the X-BPM are being developed. In this paper, we describe the methodology for developing the new compact monochromatic X-ray BPM, including its instrumentation, detector modeling, and future plan.

Monochromatic light-emitting diode (LED source in layers hens during the second production cycle

Directory of Open Access Journals (Sweden)

Rodrigo Borille

2015-09-01

Full Text Available ABSTRACTLight is an important environmental factor for birds, allowing not only their vision, but also influencing their physiological responses, such as behavioral and reproductive activity. The objective of this experiment was to evaluate the impact of different colors of monochromatic light (LED sources in laying hens production during the second laying cycle. The study was conducted in an experimental laying house during 70 days. A total of 300 laying hens Isa Brown® genetic strain, aged 95 weeks, in the second laying cycle were used in the study. The artificial light sources used were blue, yellow, green, red and white. The light regimen was continuous illumination of 17 h per day (12 h natural and 5 h artificial in a daily light regimen of 17L:5D (light: dark. The Latin Square design was adopted with five treatments (five colors divided into five periods, and five boxes, with six replicates of ten birds in each box. The production and egg quality were evaluated. The different colors of light source did not affect production parameters or egg quality (p > 0.05. The monochromatic light source may be considered as an alternative to artificial lighting in laying hens during the second production cycle.

Radiation protection measures in the case of incidents and radiation accidents

International Nuclear Information System (INIS)

Herzberg, B.

1976-01-01

Measures to be taken in the case of radiation accidents connected with an unusually high radiation exposure to persons, the amounts of which exceed the limiting values, with depend on whether there has been an external or an internal exposure. In order to give further treatment in the case of whole-body or partial-body irradiation, it is necessary to estimate the exposure dose. In nuclear medicine the accident doses are generally low, i.e. acute radiation damage does not occur here, and immediate measures are not necessary. Therapeutic measures in the case of incorporation accidents are only necessary when the maximum amounts for the nuclide in question recommended by the ICRP has been reached or exceeded in the organism. However, decorporation measures ought to be carried out only by qualified radiation protection physicians. The type of radiation accident which occurs most frequently in nuclear medicine is radiation exposure as a result of contamination. If in the case of contamination of a person the measurement exceeds the radioactivity limit, the decontamination measures are necessary. In the present contribution, these measures for cases without injuries are described in detail. (orig./HP) [de

A magnet lattice for a tau-charm factory suitable for both standard scheme and monochromatization scheme

International Nuclear Information System (INIS)

Beloshitsky, P.

1992-06-01

A versatile magnet lattice for a tau-charm factory is considered in this report. The main feature of this lattice is the possibility to use it for both standard flat beam scheme and beam monochromatization scheme. The detailed description of the lattice is given. The restrictions following the compatibility of both schemes are discussed

Non-Directional Radiation Spread Modeling and Non-Invasive Estimating the Radiation Scattering and Absorption Parameters in Biological Tissue

Directory of Open Access Journals (Sweden)

S. Yu. Makarov

2015-01-01

Full Text Available The article dwells on a development of new non-invasive measurement methods of optical parameters of biological tissues, which are responsible for the scattering and absorption of monochromatic radiation. It is known from the theory of radiation transfer [1] that for strongly scattering media, to which many biological tissues pertain, such parameters are parameters of diffusion approximation, as well as a scattering coefficient and an anisotropy parameter.Based on statistical modeling the paper examines a spread of non-directional radiation from a Lambert light beam with the natural polarization that illuminates a surface of the biological tissue. Statistical modeling is based on the Monte Carlo method [2]. Thus, to have the correct energy coefficient values of Fresnel reflection and transmission in simulation of such radiation by Monte Carlo method the author uses his finding that is a function of the statistical representation for the incidence of model photons [3]. The paper describes in detail a principle of fixing the power transmitted by the non-directional radiation into biological tissue [3], and the equations of a power balance in this case.Further, the paper describes the diffusion approximation of a radiation transfer theory, often used in simulation of radiation propagation in strongly scattering media and shows its application in case of fixing the power transmitted into the tissue. Thus, to represent an uneven power distribution is used an approximating expression in conditions of fixing a total input power. The paper reveals behavior peculiarities of solution on the surface of the biological tissue inside and outside of the incident beam. It is shown that the solution in the region outside of the incident beam (especially far away from it, essentially, depends neither on the particular power distribution across the surface, being a part of the tissue, nor on the refractive index of the biological tissue. It is determined only by

Properties of light transition radiation of 660 MeV proton inclined incidence (γ=1.7) on a thick nickel plate. II

International Nuclear Information System (INIS)

Zrelov, V.P.; Pavlovic, P.; Ruzicka, J.

1975-01-01

The basic properties of transition radiation in the visible fraction of the spectrum have been calculated for 660 MeV protons (γ=1.7) obliquely incident on a thick nickel plate in vacuum. The angular distributions of the summary radiation (i.e. the sums of radiations of various polarizations) both 'forward' and 'backward' for different azimuthal planes are presented in tables and diagrams for different particle inclination angles to the separation boundary. The examples of angular distributions of radiation having various polarizations (at the inclination angle of 45 0 ) show that they differ considerably. The spectra of summary radiation are of a monotonous character. The calculations have shown that in a relativistic case the forward radiation is concentrated near the direction of particle motion and backward radiation moves in an opposite direction with respect to that of the particle inclination. The dependence of the total yield of forward and backward transition radiations upon the particle inclination angle is approximately cos 2 psi. (Auth.)

Incidence, causative mechanisms, and anatomic localization of stroke in pituitary adenoma patients treated with postoperative radiation therapy versus surgery alone

NARCIS (Netherlands)

Sattler, Margriet; Vroomen, Patrick; Sluiter, Wim J.; Schers, Henk J.; van den Berg, Gerrit; Langendijk, Johannes A.; Wolffenbuttel, Bruce H. R.; van den Bergh, Alphons C. M.; van Beek, Andre P.

2013-01-01

PURPOSE: To assess and compare the incidence of stroke and stroke subtype in pituitary adenoma patients treated with postoperative radiation therapy (RT) and surgery alone. METHODS AND MATERIALS: A cohort of 462 pituitary adenoma patients treated between 1959 and 2008 at the University Medical

Physics Reach with a Monochromatic Neutrino Beam from Electron Capture

CERN Document Server

Bernabeu, J.; Espinoza, C.; Lindroos, M.

2005-01-01

Neutrino oscillation experiments from different sources have demonstrated non-vanishing neutrino masses and flavour mixings. The next experiments have to address the determination of the connecting mixing U(e3) and the existence of the CP violating phase. Whereas U(e3) measures the strength of the oscillation probability in appearance experiments, the CP phase acts as a phase-shift in the interference pattern. Here we propose to separate these two parameters by energy dependence, using the novel idea of a monochromatic neutrino beam facility based on the acceleration of ions that decay fast through electron capture. Fine tuning of the boosted neutrino energy allows precision measurements able to open a window for the discovery of CP violation, even for a mixing as small as 1 degree

Suppressing effect of low-dose ionizing radiation on incidence of type I diabetes of NOD mice

International Nuclear Information System (INIS)

Nomura, T.; Makino, N.; Oda, T.; Sakai, K.

2002-01-01

In the present study we examined the effects of 0.5 Gy of ionizing radiation, given acutely or chronically, on the incidence of type I diabetes in non-obese diabetic mice was examined. NOD mice are characterized by a progressive loss of insulin-producing cells in the pancreas by autoimmune mechanisms. The results suggest that the suppressive effects on the onset of he diabetes by the low dose irradiation are explain by the induction of the antioxidative activity

3D IMAGING USING COHERENT SYNCHROTRON RADIATION

Directory of Open Access Journals (Sweden)

Peter Cloetens

2011-05-01

Full Text Available Three dimensional imaging is becoming a standard tool for medical, scientific and industrial applications. The use of modem synchrotron radiation sources for monochromatic beam micro-tomography provides several new features. Along with enhanced signal-to-noise ratio and improved spatial resolution, these include the possibility of quantitative measurements, the easy incorporation of special sample environment devices for in-situ experiments, and a simple implementation of phase imaging. These 3D approaches overcome some of the limitations of 2D measurements. They require new tools for image analysis.

Accuracy of Dual-Energy Virtual Monochromatic CT Numbers: Comparison between the Single-Source Projection-Based and Dual-Source Image-Based Methods.

Science.gov (United States)

Ueguchi, Takashi; Ogihara, Ryota; Yamada, Sachiko

2018-03-21

To investigate the accuracy of dual-energy virtual monochromatic computed tomography (CT) numbers obtained by two typical hardware and software implementations: the single-source projection-based method and the dual-source image-based method. A phantom with different tissue equivalent inserts was scanned with both single-source and dual-source scanners. A fast kVp-switching feature was used on the single-source scanner, whereas a tin filter was used on the dual-source scanner. Virtual monochromatic CT images of the phantom at energy levels of 60, 100, and 140 keV were obtained by both projection-based (on the single-source scanner) and image-based (on the dual-source scanner) methods. The accuracy of virtual monochromatic CT numbers for all inserts was assessed by comparing measured values to their corresponding true values. Linear regression analysis was performed to evaluate the dependency of measured CT numbers on tissue attenuation, method, and their interaction. Root mean square values of systematic error over all inserts at 60, 100, and 140 keV were approximately 53, 21, and 29 Hounsfield unit (HU) with the single-source projection-based method, and 46, 7, and 6 HU with the dual-source image-based method, respectively. Linear regression analysis revealed that the interaction between the attenuation and the method had a statistically significant effect on the measured CT numbers at 100 and 140 keV. There were attenuation-, method-, and energy level-dependent systematic errors in the measured virtual monochromatic CT numbers. CT number reproducibility was comparable between the two scanners, and CT numbers had better accuracy with the dual-source image-based method at 100 and 140 keV. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Synchrotron-radiation experiments with recoil ions

International Nuclear Information System (INIS)

Levin, J.C.

1989-01-01

Studies of atoms, ions and molecules with synchrotron radiation have generally focused on measurements of properties of the electrons ejected during, or after, the photoionization process. Much can also be learned, however, about the atomic or molecular relaxation process by studies of the residual ions or molecular fragments following inner-shell photoionization. Measurements are reported of mean kinetic energies of highly charged argon, krypton, and xenon recoil ions produced by vacancy cascades following inner-shell photoionization using white and monochromatic synchrotron x radiation. Energies are much lower than for the same charge-state ions produced by charged-particle impact. The results may be applicable to design of future angle-resolved ion-atom collision experiments. Photoion charge distributions are presented and compared with other measurements and calculations. Related experiments with synchrotron-radiation produced recoil ion, including photoionization of stored ions and measurement of shakeoff in near-threshold excitation, are briefly discussed. 24 refs., 6 figs., 1 tab

Parametrization of the average ionization and radiative cooling rates of carbon plasmas in a wide range of density and temperature

OpenAIRE

Gil de la Fe, Juan Miguel; Rodriguez Perez, Rafael; Florido, Ricardo; Garcia Rubiano, Jesus; Mendoza, M.A.; Nuez, A. de la; Espinosa, G.; Martel Escobar, Carlos; Mínguez Torres, Emilio

2013-01-01

In this work we present an analysis of the influence of the thermodynamic regime on the monochromatic emissivity, the radiative power loss and the radiative cooling rate for optically thin carbon plasmas over a wide range of electron temperature and density assuming steady state situations. Furthermore, we propose analytical expressions depending on the electron density and temperature for the average ionization and cooling rate based on polynomial fittings which are valid for the whole range...

Causality of relationship between paternal radiation exposure and leukaemia incidence in the children of Sellafield workers

International Nuclear Information System (INIS)

Wheldon, T.E.; Mairs, R.J.; Barrett, A.

1992-01-01

In this letter the author comments on K.E. Baverstock's case (1991) against the likelihood of a causal relationship between reported leukemia incidence and paternal radiation dose in the children of Sellafield workers, and emphasizes the desirability of devising experimental tests of the germ-cell line damage hypothesis as well as the evaluation of its plausibility. Particular reference is made to the role played by dose-rates and by the two-hit model for childhood acute leukemia. (Letter to the Editor)

Increased incidence of myelodysplastic syndrome and acute myeloid leukemia following breast cancer treatment with radiation alone or combined with chemotherapy: a registry cohort analysis 1990-2005

International Nuclear Information System (INIS)

Kaplan, Henry G; Malmgren, Judith A; Atwood, Mary K

2011-01-01

Our objective was to measure myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML) risk associated with radiation and/or chemotherapy breast cancer (BC) treatment. Our study cohort was composed of BC patients diagnosed from 1990 to 2005 and followed up for blood disorders, mean length of follow up = 7.17 years, range 2-18 years. 5790 TNM stage 0-III patients treated with surgery alone, radiation and/or chemotherapy were included. Patients without surgery (n = 111), with stem cell transplantation (n = 98), unknown or non-standard chemotherapy regimens (n = 94), lost to follow up (n = 66) or 'cancer status unknown' (n = 67) were excluded. Rates observed at our community based cancer care institution were compared to SEER incidence data for rate ratio (RR) calculations. 17 cases of MDS/AML (10 MDS/7 AML) occurred during the follow up period, crude rate .29% (95% CI = .17, .47), SEER comparison RR = 3.94 (95% CI = 2.34, 6.15). The RR of MDS in patients age < 65 comparing our cohort incidence to SEER incidence data was 10.88 (95% CI = 3.84, 24.03) and the RR of AML in patients age < 65 was 5.32 (95% CI = 1.31, 14.04). No significant increased risk of MDS or AML was observed in women ≥ 65 or the surgery/chemotherapy-only group. A RR of 3.32 (95% CI = 1.42, 6.45) was observed in the surgery/radiation-only group and a RR of 6.32 (95% CI = 3.03, 11.45) in the surgery/radiation/chemotherapy group. 3 out of 10 MDS cases died of disease at an average 3.8 months post diagnosis and five of seven AML cases died at an average 9 months post diagnosis. An elevated rate of MDS and AML was observed among breast cancer patients < 65, those treated with radiation and those treated with radiation and chemotherapy compared to available population incidence data. Although a small number of patients are affected, leukemia risk associated with treatment and younger age is significant

Effects of radiation on the incidence of prostate cancer among Nagasaki atomic bomb survivors.

Science.gov (United States)

Kondo, Hisayoshi; Soda, Midori; Mine, Mariko; Yokota, Kenichi

2013-10-01

Atomic bomb survivors have been reported to have an increased risk of some cancers, especially leukemia. However, the risk of prostate cancer in atomic bomb survivors is not known to have been examined previously. This study examined the association between atomic bomb radiation and the incidence of prostate cancer among male Nagasaki atomic bomb survivors. The subjects were classified by distance from the hypocenter into a proximal group (bomb survivors who were alive in 1996. The Cox proportional hazard model was used to estimate the risk of prostate cancer development, with adjustment for age at atomic bomb explosion, attained age, smoking status, and alcohol consumption. Compared with the distal group, the proximal group had significant increased risks of total, localized, and high-grade prostate cancer (relative risk and 95% confidence interval: 1.51 [1.21-1.89]; 1.80 [1.26-2.57]; and 1.88 [1.20-2.94], respectively). This report is the first known to reveal a significant relationship between atomic bomb radiation and prostate cancer. © 2013 Japanese Cancer Association.

Epidemiological studies on disturbances of human fetal development in areas with various doses of natural background radiation. I. Relationship between incidences of Down's syndrome or visible malformation and gonad dose equivalent rate of natural background radiation

International Nuclear Information System (INIS)

Ujeno, Y.

1985-01-01

The relationship between environmental radiation to the gonads and incidences of Down's syndrome and visible malformation was analyzed using Kendall's rank correlation method. The subjects, studied during a 3-yr period (1979-1981), were inhabitants of 46 prefectures in Japan that had various dose rates of natural background ionizing radiation. Results showed that the natural background very low-dose radiation rate was not a predominant factor responsible for inducing Down's syndrome or other visible malformations

Measurement of the radiation incident on ALS NdFeB permanent magnet insertion device structures and a determination of their lifetime

International Nuclear Information System (INIS)

Krebs, G.F.; Holmes, M.

1997-05-01

Measurements of the radiation incident on ALS insertion device NdFeB permanent magnet structures were carried out using thermoluminescence dosimeters. A plastic scintillator gamma telescope was utilized to unravel the various contributions to the integrated dose. Magnet lifetimes were calculated for various operational conditions

Direct detection of darkmatter in radiative seesaw model

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Daniel; Schwetz, Thomas [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Toma, Takashi [Institute for Theoretical Physics, Kanazawa University (Japan)

2012-07-01

In the radiative seesaw model proposed by Ma, we assume that the lightest right-handed neutrino is the Dark Matter candidate and almost degenerated with the second lightest right-handed neutrino. Thus, elastic Dark Matter-nucleus scattering is suppressed. Inelastic scattering is induced by a lepton-loop coupled to the photon. Effectively, there are charge-charge, dipole-charge and dipole-dipole interactions. We present the event rate of the model and compare it with existing data. Moreover, monochromatic photons from the decay of the excited Dark Matter state are discussed.

Effects of synchrotron radiation spectrum energy on polymethyl methacrylate photosensitivity to deep x-ray lithography

International Nuclear Information System (INIS)

Mekaru, Harutaka; Utsumi, Yuichi; Hattori, Tadashi

2003-01-01

Since X-ray lithography requires a high photon flux to achieve deep resist exposure, a synchrotron radiation beam, which is not monochromatized, is generally used as a light source. If the synchrotron radiation beam is monochromatized, photon flux will decrease rapidly. Because of this reason, the wavelength dependence of the resist sensitivity has not been investigated for deep X-ray lithography. Measuring the spectrum of a white beam with a Si solid-state detector (SSD) is difficult because a white beam has a high intensity and an SSD has a high sensitivity. We were able to measure the spectrum and the photocurrent of a white beam from a beam line used for deep X-ray lithography by keeping the ring current below 0.05 mA. We evaluated the characteristics of the output beam based on the measured spectrum and photocurrent, and used them to investigate the relationship between the total exposure energy and the dose-processing depth with polymethyl methacrylate (PMMA). We found that it is possible to guess the processing depth of PMMA from the total exposure energy in deep X-ray lithography. (author)

X-ray topographic method of investigation of phase objects

International Nuclear Information System (INIS)

Levonyan, L.V.

2001-01-01

The intensity distribution of the monochromatized synchrotron radiation transmitting through the phase object and crystal-analyzer in Laue geometry is considered. It is shown that the local angular deviation of the incident radiation caused by the refraction on structural inhomogeneities of the object under investigation is directly transferred to the X-ray topographic image. In the absence of the phase object the latter consists of parallel straight fringes with a slowly decreasing period. The presence of the phase object changes the shape and period of fringes. The influence of the spatial and temporal coherence on the image is discussed. 5 refs

Low-energy x-ray dosimetry studies (7 to 17.5 keV) with synchroton radiation

International Nuclear Information System (INIS)

Ipe, N.E.; Bellamy, H.; Flood, J.R.

1995-06-01

Unique properties of synchrotron radiation (SR), such as its high intensity, brightness, polarization, and broad spectral distribution (extending from x-ray to infra-red wavelengths) make it an attractive light source for numerous experiments. As SR facilities are rapidly being built all over the world, they introduce the need for low-energy x-ray dosemeters because of the potential radiation exposure to experimenters. However, they also provide a unique opportunity for low-energy x-ray dosimetry studies because of the availability of monochromatic x-ray beams. Results of such studies performed at the Stanford Synchrotron Radiation Laboratory are described. Lithium fluoride TLDs (TLD-100) of varying thicknesses (0.015 to 0.08 cm) were exposed free in air to monochromatic x-rays (7 to 17.5 keV). These exposures were monitored with ionization chambers. The response (nC/Gy) was found to increase with increasing TLD thickness and with increasing beam energy. A steeper increase in response with increasing energy was observed with the thicker TLDs. The responses at 7 and 17.5 keV were within a factor of 2.3 and 5.2 for the 0.015 and 0.08 cm-thick TLDs, respectively. The effects of narrow (beam size smaller than the dosemeter) and broad (beam size larger than the dosemeter) beams on the response of the TLDs are also reported

X-ray radiation damage of organic semiconductor thin films during grazing incidence diffraction experiments

Energy Technology Data Exchange (ETDEWEB)

Neuhold, A., E-mail: alfred.neuhold@tugraz.at [Institute of Solid State Physics, Graz University of Technology, Graz (Austria); Novak, J.; Flesch, H.-G.; Moser, A.; Djuric, T. [Institute of Solid State Physics, Graz University of Technology, Graz (Austria); Grodd, L.; Grigorian, S.; Pietsch, U. [Institute of Physics, University Siegen (Germany); Resel, R. [Institute of Solid State Physics, Graz University of Technology, Graz (Austria)

2012-08-01

Since modern synchrotrons with highly intense X-ray beams are in use to investigate organic materials, the stability of soft matter materials during beam exposure is a crucial issue. Grazing incidence X-ray diffraction and specular X-ray reflectivity measurements were performed on thin films of organic semiconducting materials, like poly(3-hexylthiophene) (P3HT), sexithiophene and pentacene. These films were irradiated with an average flux density between 10{sup 15} and 10{sup 16} photons/(s mm{sup 2}) and evidenced a different stability in synchrotron X-ray radiation. The semi-crystalline P3HT showed a clear intensity decrease of the 1 0 0 Bragg peak and 0 2 0 Bragg peak compared to the rather stable diffraction features of the molecular crystals sexithiophene and pentacene. The difference in synchrotron X-ray radiation stability is explained by the interaction of the X-ray beam with the individual chemical components in the molecules as well as by the different crystallinities of the materials. Furthermore, the semi-crystalline P3HT film exhibited an increase of film thickness after irradiation and the surface roughness slightly decreased. To summarize, this study shows a strong influence of synchrotron X-ray radiation to specific organic thin films like e.g. P3HT, while others like pentacene and sexithiophene are observed as quite stable.

Fusion of colour and monochromatic images with edge emphasis

Directory of Open Access Journals (Sweden)

Rade M. Pavlović

2014-02-01

Full Text Available We propose a novel method to fuse true colour images with monochromatic non-visible range images that seeks to encode important structural information from monochromatic images efficiently but also preserve the natural appearance of the available true chromacity information. We utilise the β colour opponency channel of the lαβ colour as the domain to fuse information from the monochromatic input into the colour input by the way of robust grayscale fusion. This is followed by an effective gradient structure visualisation step that enhances the visibility of monochromatic information in the final colour fused image. Images fused using this method preserve their natural appearance and chromacity better than conventional methods while at the same time clearly encode structural information from the monochormatic input. This is demonstrated on a number of well-known true colour fusion examples and confirmed by the results of subjective trials on the data from several colour fusion scenarios. Introduction The goal of image fusion can be broadly defined as: the representation of visual information contained in a number of input images into a single fused image without distortion or loss of information. In practice, however, a representation of all available information from multiple inputs in a single image is almost impossible and fusion is generally a data reduction task.  One of the sensors usually provides a true colour image that by definition has all of its data dimensions already populated by the spatial and chromatic information. Fusing such images with information from monochromatic inputs in a conventional manner can severely affect natural appearance of the fused image. This is a difficult problem and partly the reason why colour fusion received only a fraction of the attention than better behaved grayscale fusion even long after colour sensors became widespread. Fusion method Humans tend to see colours as contrasts between opponent

AlGaAs/GaAs photovoltaic converters for high power narrowband radiation

Energy Technology Data Exchange (ETDEWEB)

Khvostikov, Vladimir; Kalyuzhnyy, Nikolay; Mintairov, Sergey; Potapovich, Nataliia; Shvarts, Maxim; Sorokina, Svetlana; Andreev, Viacheslav [Ioffe Physical-Technical Institute, 26 Polytechnicheskaya, St. Petersburg, 194021 (Russian Federation); Luque, Antonio [Ioffe Physical-Technical Institute, 26 Polytechnicheskaya, St. Petersburg, 194021, Russia and Instituto de Energia Solar, Universidad Politecnica de Madrid, Madrid (Spain)

2014-09-26

AlGaAs/GaAs-based laser power PV converters intended for operation with high-power (up to 100 W/cm{sup 2}) radiation were fabricated by LPE and MOCVD techniques. Monochromatic (λ = 809 nm) conversion efficiency up to 60% was measured at cells with back surface field and low (x = 0.2) Al concentration 'window'. Modules with a voltage of 4 V and the efficiency of 56% were designed and fabricated.

Effect of an external alternating electric field non-monochromaticity on parametric excitation of surface ion cyclotron X-modes

International Nuclear Information System (INIS)

Girka, V O; Puzyrkov, S Yu; Shpagina, V O; Shpagina, L O

2012-01-01

The application of an external alternating electric field in the range of ion cyclotron frequencies is a well-known method for the excitation of surface electromagnetic waves. The present paper is devoted to the development of a kinetic theory of parametric excitation of these eigenwaves propagating across an external steady magnetic field along the plasma boundary at the second harmonic of the ion cyclotron frequency. Unlike previous papers on this subject, parametric excitation of surface ion cyclotron X-modes is studied here under the condition of non-monochromaticity of an external alternating electric field. Non-monochromaticity of the external alternating electric field is modeled by the superposition of two uniform and monochromatic electric fields with different amplitudes and frequencies. The nonlinear boundary condition is formulated for a tangential magnetic field of the studied surface waves. An infinite set of equations for the harmonics of a tangential electric field is solved using the approximation of the wave packet consisting of the main harmonic and two nearest satellite harmonics. Two different regimes of instability have been considered. If one of the applied generators has an operation frequency that is close to the ion cyclotron frequency, then changing the amplitude of the second generator allows one to enhance the growth rate of the parametric instability or to diminish it. But if the operation frequencies of the both generators are not close to the ion cyclotron frequency, then changing the amplitudes of their fields allows one to decrease the growth rate of the instability and even to suppress its development. The problem is studied both analytically and numerically.

Advances in thin film diffraction instrumentation by X-ray optics

International Nuclear Information System (INIS)

Haase, A.

1996-01-01

The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves

Advances in thin film diffraction instrumentation by X-ray optics

Energy Technology Data Exchange (ETDEWEB)

Haase, A [Rich. Seifert and Co., Analytical X-ray Systems, Ahrensburg (Germany)

1996-09-01

The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves.

Parallel beam microradiography of dental hard tissue using synchrotron radiation and X-ray image magnification

International Nuclear Information System (INIS)

Takagi, S.; Chow, L.C.; Brown, W.E.; Dobbyn, R.C.; Kuriyama, M.

1984-01-01

A novel technique utilizing a highly parallel beam of monochromatic synchrotron radiation combined with X-ray image magnification has been used to obtain microradiographs of caries lesions in relatively thick tooth sections. Preliminary results reveal structural features not previously reported. This technique holds the promise of allowing one to follow the structural changes accompanying the formation, destruction and chemical repair of mineralized tissue in real time. (orig.)

Cancer incidence in atomic bomb survivors. Part IV: Comparison of cancer incidence and mortality

International Nuclear Information System (INIS)

Ron, E.; Preston, D.L.; Mabuchi, Kiyohiko; Thompson, D.E.; Soda, Midori

1994-01-01

This report compares cancer incidence and mortality among atomic bomb survivors in the Radiation Effects Research Foundation Life Span Study (LSS) cohort. Because the incidence data are derived from the Hiroshima and Nagasaki tumor registries, case ascertainment is limited to the time (1958-1987) and geographic restrictions (Hiroshima and Nagasaki) of the registries, whereas mortality data are available from 1950-1987 anywhere in Japan. With these conditions, there were 9,014 first primary incident cancer cases identified among LSS cohort members compared with 7,308 deaths for which cancer was listed as the underlying cause of death on death certificates. When deaths were limited to those occurring between 1958-1987 in Hiroshima or Nagasaki, there were 3,155 more incident cancer cases overall, and 1,262 more cancers of the digestive system. For cancers of the oral cavity and pharynx, skin, breast, female and male genital organs, urinary system and thyroid, the incidence series was at least twice as large as the comparable mortality series. Although the incidence and mortality data are dissimilar in many ways, the overall conclusions regarding which solid cancers provide evidence of a significant dose response generally confirm the mortality findings. When either incidence or mortality data are evaluated, significant excess risks are observed for all solid cancers, stomach, colon, liver (when it is defined as primary liver cancer or liver cancer not otherwise specified on the death certificate), lung, breast, ovary and urinary bladder. No significant radiation effect is seen for cancers of the pharynx, rectum, gallbladder, pancreas, nose, larynx, uterus, prostate or kidney in either series. There is evidence of a significant excess of nonmelanoma skin cancer in the incidence data, but not in the mortality series. 19 refs., 2 figs., 10 tabs

Report on promotion of utilization of radiation

International Nuclear Information System (INIS)

1987-01-01

This report presents results of studies made by the Atomic Energy Commission concerning research and development activities to be carried out in future to promote the utilization of radiation. First, the current state of radiation utilization is described, centering on practical applications, research and development activities (for practical and advanced applications), and international cooperation (with developing and advanced nations). The second part deals with activities required in future to promote practical utilization of radiation, research and development of advanced techniques, and cooperation to be offered to developing countries. Third, specific measures to be carried out for effective radiation utilization are described. For γ-rays and electron beams, which are widely in use at present, there are some economic and social problems remaining to be solved. For advanced utilization of radiation beams, further efforts should be focused on basic research on π-meson and μ-particle beams and their application to canser treatment and nuclear fusion; research on monochromatic neutron beams; application of RI beams to the development of new materials and new analysis techniques, application of epithermal neutron beams to elementary radiography and CT; etc. The utilization, application and development of tracers are also described. (Nogami, K.)

A quasi-monochromatic X-rays source for art painting pigments investigation

Energy Technology Data Exchange (ETDEWEB)

Albertin, F.; Franconieri, A.; Gambaccini, M.; Petrucci, F.; Chiozzi, S. [University of Ferrara, Department of Physics and INFN, Ferrara (Italy); Moro, D. [University of Padova, Department of Physics, Padova (Italy); LNL - INFN, Legnaro, Padova (Italy)

2009-08-15

Monochromatic X-ray sources can be used for several applications, like in medicine or in studying our cultural heritage. We are investigating imaging systems based on a tuneable energy band X-ray source, to obtain an element mapping of painting layers using the K-edge technique. The narrow energy band beams are obtained with conventional X-ray source via Bragg diffraction on a mosaic crystal; such an analysis has been performed at different diffraction angles, tuning the energy to investigate spectra of interest from the artistic point of view, like zinc and copper. In this paper the characteristics of the system in terms of fluence rate are reported, and first results of this technique on canvas samples and painting are presented. (orig.)

Recovery from Iridium-192 flakes of a radioactive source for industrial use after a radiation incident

International Nuclear Information System (INIS)

Cruz, W.H.; Zapata, L.A.

2013-01-01

The Iridium-192 ( 192 Ir) is the most used and ideal for industrial radiography applications, especially in petrochemical plants and pipelines and provides better contrast sensitivity for thick (25.4 mm). This source has constructive sealed double encapsulation, the internal capsule containing stainless steel to radioactive material in the form of flakes and welded with TIG process. The radiological incident happened at a gas station fuel sales in circumstances in which there was a homogeneity test welds a tank, the flakes or Ir-192 fell off his ponytail and left scattered over an area of 2 m 2 , some fell flat areas and other land so collected in lead shielding and metal container and ground source. Full recovery of the leaflets was performed at the Division of radioactive waste management (GRRA) gaining a total of 22 flakes with no radiation risk to staff performance and installation and the conclusion was reached that the misapplicaion of TIG welding was the main cause the incident. (author)

Results of the implementation of a learning system with incidents in an radiotherapy department

International Nuclear Information System (INIS)

Radicchi, Lucas Augusto; Vilela, Ellen Pedroso Severino; Faustino, Fabio de Lima C.; Rodrigues, Fernanda Arantes C.; Gomes, Franciele N.; Souza, Guilherme Vicente de; Silva, Rose Marta S.; Toledo, Jose Carlos de

2016-01-01

An incident learning system (ILS) is an important tool for improving aspects of patient and staff safety. In radiation oncology, ILS has been implemented both at the institutional level as at the national level, allowing to share lessons learned from incidents that have already occurred. The objective of this study is to present the preliminary results of the ILS implemented in a radiation oncology department. In total, 128 incidents were reviewed by a multidisciplinary committee, and the professional groups that registered more were medical physicists, radiation oncologists and radiation therapists. In addition, incidents have occurred and have been detected mainly in the treatment step. The incident learning system proved to be an important process improvement tool, according to the results shown,the improvement actions proposed and the perception of the people involved. (author)

Cancer incidence study in Mesa County, Colorado

International Nuclear Information System (INIS)

Ouimette, D.R.; Ferguson, S.W.; Zoglo, D.; Murphy, S.; Alley, S.; Bahler, S.

1983-01-01

In November of 1982 the Colorado Department of Health completed an epidemiologic investigation of leukemia, multiple myeloma, and cancers of the lung, stomach, pancreas and colon in Mesa County, Colorado for the years 1970 to 1979. This investigation was performed in response to a concern that the presence of uranium mill tailings in some Mesa County homes presents a potential cancer hazard. The results of the investigation show that the incidence of multiple myeloma, colon, stomach and pancreatic cancer are not above expected rates. The incidence of leukemia is not above expected rates for the entire study period, 1970 to 1979. The incidence of lung cancer appears elevated when compared to the The Third National Cancer Survey data for Colorado but lower than expected when compared to Surveillance, Epidemiology and End Results data. To further examine the leukemia and lung cancer incidence findings, a case/control study was conducted. The controls consisted of colon, stomach and pancreatic cancer cases. The results of the leukemia case/control analysis show no association with the radiation exposure variables: occupational radiation exposure; uranium mining exposure; having ever lived in a type A home (uranium tailings home); and radiation therapy. The lung cancer case/control analysis shows a significant association with only the radiation exposure variable, uranium mining history, indicating cases were more likely to have been uranium miners than were controls. As with leukemia, the study found no association between lung cancer and living in a uranium mill tailings home. The relatively low radiation exposures typical of type A homes and the small number of persons exposed make it very difficult to establish, by epidemiologic methods, that a risk exists

2011 Japanese Nuclear Incident

Science.gov (United States)

EPA’s RadNet system monitored the environmental radiation levels in the United States and parts of the Pacific following the Japanese Nuclear Incident. Learn about EPA’s response and view historical laboratory data and news releases.

Selective surface functionalization of polystyrene induced by synchrotron or UV radiation in the presence of oxygen or acrylic acid vapors

International Nuclear Information System (INIS)

Kessler, Felipe; Kuhn, Sidiney; Weibel, Daniel E.

2009-01-01

Efficient surface functionalization of Polystyrene (PS) thin films by electromagnetic radiation in combination with a reactive gaseous atmosphere was obtained. Monochromatic synchrotron (SR) or polychromatic UV radiation were used as excitation sources. When SR was used, O 2 was introduced after irradiation into the UHV chamber. UV irradiation was carried out keeping a constant flow of O 2 or acrylic acid (AA) vapors during the photolysis. FTIR-ATR and XPS-NEXAFS spectra were obtained at the UFRGS and the LNLS, Campinas respectively. PS films were functionalized by monochromatic SR and then expose to O 2 at specific transitions such us C 1s →σ * C-C excitation. It was found a high rate of COO, C=O and C-O groups at the surface (> 70%). UV-assisted treatment in the presence of AA vapors showed that an efficient polymerization process took place, such as, it was observed in previous AA low pressure RF plasma treatments. UV-assisted functionalization has the advantage of lower costs and simple set-up compared to plasma treatments. (author)

Effect of low-energy coherent radiation with lambda=6328 A on the survival rate of Saccharomyces cerevisial of strain 14

International Nuclear Information System (INIS)

Abramova, N.V.

1978-01-01

The effect of the continuous monochromatic coherent laser radiation on the survival rate of Saccharomyces cerevisiae of strain 14 is studied. The effect of laser radiation is judged by the change in the survival rate of the yeast culture before and after the irradiation. The decrease of the number of the yeast cells in the initial moments of the irradiation was observed as a result of the laser irradiation. Then the rapid decrease of the number of cells with time changes into their constant number. It is established that the low-energy coherent radiation decreases the survival rate by 30-40%

Grazing incidence optics; Proceedings of the Meeting, Orlando, FL, Apr. 3, 4, 1986

Science.gov (United States)

Osantowski, John F. (Editor); Van Speybroeck, Leon (Editor)

1986-01-01

Papers are presented on the diffraction-limited performance of grazing incidence optical systems; transverse ray aberrations of Wolter type 1 telescopes; hybrid X-ray telescope systems; surface characterization of grazing incidence optics in the extreme UV and X-ray regions; and the surface roughness properties of synchrotron radiation optics. Topics discussed include the simulation of free-abrasive grinding of grazing incidence mirrors with vertical-honing and flexible blades; mirrors for the Extreme Ultraviolet Explorer; the design and development of conical X-ray imaging mirrors; thermal loading considerations for synchrotron radiation mirrors; and grazing incidence optics for synchrotron radiation insertion-device beams. Consideration is given to the interpretation of glancing incidence scattering measurements; damage processes in short wavelength coated FEL optics; the replication of grain incidence optics; and the assembly and alignment of the Technology Mirror Assembly.

Analysis of a radiation incident with intraoral dental radiological equipment

International Nuclear Information System (INIS)

Malone, J.F.

1996-01-01

A case is described involving a serious incident with dental radiological equipment, containing many lessons that may be applied to the preparation of other cases. The description includes an account of the incident, the circumstances surrounding it, the dosimetry, risk estimates and the medical consequences of the incident. In addition, some aspects of the associated legal proceedings are reviewed and assessed. As a result of the incident described, a number of conclusions are drawn with respect to important practices in ensuring the safety of installations and the value of evidence brought forward by expert witnesses. (author)

Response of vegetable organisms to quasi-monochromatic light of different duration, intensity and wavelength

Energy Technology Data Exchange (ETDEWEB)

Budagovsky, A V; Solovykh, N V [I.V.Michurin All-Russian Recearch Institute of Fruit Crops Genetics and Breeding (Russian Federation); Budagovskaya, O N [I.V.Michurin All-Russia Research and Development Institute of Gardening, Michurinsk, Tambov region (Russian Federation); Budagovsky, I A [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2015-04-30

By the example of vegetable organisms differing in structure and functional properties it is shown that their response to the action of quasi-monochromatic light from laser sources does not obey the Bunsen – Roscoe dose law. The dependence of biological effect on the irradiation time has the multimodal (multiextremal) form with alternating maxima and minima of the stimulating effect. Such a property manifests itself in the spectral ranges, corresponding to photoinduced conversion of chromoproteins of photocontrol systems and is probably related to the cyclic variations of metabolic activity in vegetable cells. (biophotonics)

Solar monochromatic images in magneto-sensitive spectral lines and maps of vector magnetic fields

Science.gov (United States)

Shihui, Y.; Jiehai, J.; Minhan, J.

1985-01-01

A new method which allows by use of the monochromatic images in some magneto-sensitive spectra line to derive both the magnetic field strength as well as the angle between magnetic field lines and line of sight for various places in solar active regions is described. In this way two dimensional maps of vector magnetic fields may be constructed. This method was applied to some observational material and reasonable results were obtained. In addition, a project for constructing the three dimensional maps of vector magnetic fields was worked out.

Ascent of arches of a monochromatic corona during the eclipse on July 31, 1981

Energy Technology Data Exchange (ETDEWEB)

Delone, A B; Makarova, E A; Sikora, Yu [Moskovskij Gosudarstvennyj Univ. (USSR). Gosudarstvennyj Astronomicheskij Inst. ' ' GAISh' ' ; Slovenska Akademia Vied, Bratislava [Czechoslovakia

1984-04-01

Velocities of some details of monochromatic corona on July 31, 1981, were measured in the sky plane at the west limb. The ascent of arches and plasmoids clots in the condensations with velocities of about 10 km/s were observed in the green line Fe 14lambda5303. In the red line Fe10lambda6374 the velocities of ascent of two arches were about 11-25 km/s. Each of the investigated details is seen only in one emission line and is absent bout 11-25 km/s.

Energy dependence of CP-violation reach for monochromatic neutrino beam

Science.gov (United States)

Bernabéu, José; Espinoza, Catalina

2008-06-01

The ultimate goal of future neutrino facilities is the determination of CP violation in neutrino oscillations. Besides | U (e 3) | ≠ 0, this will require precision experiments with a very intense neutrino source and energy control. With this objective in mind, the creation of monochromatic neutrino beams from the electron capture decay of boosted ions by the SPS of CERN has been proposed. We discuss the capabilities of such a facility as a function of the energy of the boost and the baseline for the detector. We compare the physics potential for two different configurations: (I) γ = 90 and γ = 195 (maximum achievable at present SPS) to Frejus; (II) γ = 195 and γ = 440 (maximum achievable at upgraded SPS) to Canfranc. We conclude that the SPS upgrade to 1000 GeV is important to reach a better sensitivity to CP violation iff it is accompanied by a longer baseline.

Energy dependence of CP-violation reach for monochromatic neutrino beam

International Nuclear Information System (INIS)

Bernabeu, Jose; Espinoza, Catalina

2008-01-01

The ultimate goal of future neutrino facilities is the determination of CP violation in neutrino oscillations. Besides |U(e3)|≠0, this will require precision experiments with a very intense neutrino source and energy control. With this objective in mind, the creation of monochromatic neutrino beams from the electron capture decay of boosted ions by the SPS of CERN has been proposed. We discuss the capabilities of such a facility as a function of the energy of the boost and the baseline for the detector. We compare the physics potential for two different configurations: (I) γ=90 and γ=195 (maximum achievable at present SPS) to Frejus; (II) γ=195 and γ=440 (maximum achievable at upgraded SPS) to Canfranc. We conclude that the SPS upgrade to 1000 GeV is important to reach a better sensitivity to CP violation iff it is accompanied by a longer baseline

Targeting safety improvements through identification of incident origination and detection in a near-miss incident learning system

International Nuclear Information System (INIS)

Novak, Avrey; Nyflot, Matthew J.; Ermoian, Ralph P.; Jordan, Loucille E.; Sponseller, Patricia A.; Kane, Gabrielle M.; Ford, Eric C.; Zeng, Jing

2016-01-01

Purpose: Radiation treatment planning involves a complex workflow that has multiple potential points of vulnerability. This study utilizes an incident reporting system to identify the origination and detection points of near-miss errors, in order to guide their departmental safety improvement efforts. Previous studies have examined where errors arise, but not where they are detected or applied a near-miss risk index (NMRI) to gauge severity. Methods: From 3/2012 to 3/2014, 1897 incidents were analyzed from a departmental incident learning system. All incidents were prospectively reviewed weekly by a multidisciplinary team and assigned a NMRI score ranging from 0 to 4 reflecting potential harm to the patient (no potential harm to potential critical harm). Incidents were classified by point of incident origination and detection based on a 103-step workflow. The individual steps were divided among nine broad workflow categories (patient assessment, imaging for radiation therapy (RT) planning, treatment planning, pretreatment plan review, treatment delivery, on-treatment quality management, post-treatment completion, equipment/software quality management, and other). The average NMRI scores of incidents originating or detected within each broad workflow area were calculated. Additionally, out of 103 individual process steps, 35 were classified as safety barriers, the process steps whose primary function is to catch errors. The safety barriers which most frequently detected incidents were identified and analyzed. Finally, the distance between event origination and detection was explored by grouping events by the number of broad workflow area events passed through before detection, and average NMRI scores were compared. Results: Near-miss incidents most commonly originated within treatment planning (33%). However, the incidents with the highest average NMRI scores originated during imaging for RT planning (NMRI = 2.0, average NMRI of all events = 1.5), specifically

Targeting safety improvements through identification of incident origination and detection in a near-miss incident learning system

Energy Technology Data Exchange (ETDEWEB)

Novak, Avrey; Nyflot, Matthew J.; Ermoian, Ralph P.; Jordan, Loucille E.; Sponseller, Patricia A.; Kane, Gabrielle M.; Ford, Eric C.; Zeng, Jing, E-mail: jzeng13@uw.edu [Department of Radiation Oncology, University of Washington Medical Center, 1959 NE Pacific Street, Campus Box 356043, Seattle, Washington 98195 (United States)

2016-05-15

Purpose: Radiation treatment planning involves a complex workflow that has multiple potential points of vulnerability. This study utilizes an incident reporting system to identify the origination and detection points of near-miss errors, in order to guide their departmental safety improvement efforts. Previous studies have examined where errors arise, but not where they are detected or applied a near-miss risk index (NMRI) to gauge severity. Methods: From 3/2012 to 3/2014, 1897 incidents were analyzed from a departmental incident learning system. All incidents were prospectively reviewed weekly by a multidisciplinary team and assigned a NMRI score ranging from 0 to 4 reflecting potential harm to the patient (no potential harm to potential critical harm). Incidents were classified by point of incident origination and detection based on a 103-step workflow. The individual steps were divided among nine broad workflow categories (patient assessment, imaging for radiation therapy (RT) planning, treatment planning, pretreatment plan review, treatment delivery, on-treatment quality management, post-treatment completion, equipment/software quality management, and other). The average NMRI scores of incidents originating or detected within each broad workflow area were calculated. Additionally, out of 103 individual process steps, 35 were classified as safety barriers, the process steps whose primary function is to catch errors. The safety barriers which most frequently detected incidents were identified and analyzed. Finally, the distance between event origination and detection was explored by grouping events by the number of broad workflow area events passed through before detection, and average NMRI scores were compared. Results: Near-miss incidents most commonly originated within treatment planning (33%). However, the incidents with the highest average NMRI scores originated during imaging for RT planning (NMRI = 2.0, average NMRI of all events = 1.5), specifically

Combined effects of radiation and other agents on the stomach cancer incidence among Mayak Atomic Plant workers

International Nuclear Information System (INIS)

Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D.; Rovny, S.I.; Sirchikov, V.A.

2000-01-01

The gravity of a problem of the combined action of radiation and other factors again was confirmed sessions UNSCEAR in May, 1998. It especially is important at study of cancer diseases in connection with the polyetiology and multistage of them development. The estimation of radiation, medico-biological factors and condition of life in occurrence of a stomach cancer among Mayak personnel was specified by case-cohort research. For a quota 503 men (157 cases of a stomach cancer, 346 men of the healthy personnel) attributive risk of the radiation factors was 8.8%, medico-biological - 57,2% (from them by greatest was influence chronic gastritis with secreting insufficiency - 35.4%), tobacco consumption - 31,6%. At an estimation of risk of a stomach cancer depending on external γ-irradiation best fitting was received at use of square-law model. The excess relative risk was 0,27 Gr -2 (F=44,5; P=0,007). For 239 Pu incorporation was not revealed of distinct connection with stomach cancer incidences. Interaction of the radiation and non-radiation factors also was appreciated. The interaction of gastritis with external γ-irradiation or 239 Pu was multiplicate. The interaction of smoking with γ-irradiation or 239 Pu incorporation was multiplicate also. The distribution histological types of a stomach cancer among the workers of Mayak plant differed in comparison with not working. Among the workers the increase poorly differentiated adenocarcinoma was observed. (author)

Combined effects of radiation and other agents on the stomach cancer incidence among Mayak Atomic Plant workers

Energy Technology Data Exchange (ETDEWEB)

Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D. [Branch No 1 of State Research Center of Public Health Ministry of the Russian Federation, Ozyorsk (Russian Federation). Biophysics Inst.; Rovny, S.I.; Sirchikov, V.A.

2000-05-01

The gravity of a problem of the combined action of radiation and other factors again was confirmed sessions UNSCEAR in May, 1998. It especially is important at study of cancer diseases in connection with the polyetiology and multistage of them development. The estimation of radiation, medico-biological factors and condition of life in occurrence of a stomach cancer among Mayak personnel was specified by case-cohort research. For a quota 503 men (157 cases of a stomach cancer, 346 men of the healthy personnel) attributive risk of the radiation factors was 8.8%, medico-biological - 57,2% (from them by greatest was influence chronic gastritis with secreting insufficiency - 35.4%), tobacco consumption - 31,6%. At an estimation of risk of a stomach cancer depending on external {gamma}-irradiation best fitting was received at use of square-law model. The excess relative risk was 0,27 Gr{sup -2} (F=44,5; P=0,007). For {sup 239}Pu incorporation was not revealed of distinct connection with stomach cancer incidences. Interaction of the radiation and non-radiation factors also was appreciated. The interaction of gastritis with external {gamma}-irradiation or {sup 239}Pu was multiplicate. The interaction of smoking with {gamma}-irradiation or {sup 239}Pu incorporation was multiplicate also. The distribution histological types of a stomach cancer among the workers of Mayak plant differed in comparison with not working. Among the workers the increase poorly differentiated adenocarcinoma was observed. (author)

Radiation tolerance of the cervical spinal cord: incidence and dose-volume relationship of symptomatic and asymptomatic late effects following high dose irradiation of paraspinal tumors

International Nuclear Information System (INIS)

Liu, Mitchell C.C.; Munzenrider, John E.; Finkelstein, Dianne; Liebsch, Norbert; Adams, Judy; Hug, Eugen B.

1997-01-01

Purpose: Low grade chordomas and chondrosarcomas require high radiation doses for effective, lasting tumor control. Fractionated, 3-D planned, conformal proton radiation therapy has been used for lesions along the base of skull and spine to deliver high target doses, while respecting constraints of critical, normal tissues. In this study, we sought to determine the incidence of myelopathy after high dose radiotherapy to the cervical spine and investigated the influence of various treatment parameters, including dose-volume relationship. Methods and Materials: Between December 1980 and March 1996, 78 patients were treated at the Massachusetts General Hospital and Harvard Cyclotron Laboratory for primary or recurrent chordomas and chondrosarcomas of the cervical spine using combined proton and photon radiation therapy. In general, the tumor dose given was between 64.5 to 79.2 CGE (Cobalt Gray Equivalent). The guidelines for maximum permissible doses to spinal cord were: ≤ 64 CGE to the spinal cord surface and ≤ 53 CGE to the spinal cord center. Dose volume histograms of the spinal cord were analyzed to investigate a possible dose and volume relationship. Results: With a mean follow-up period of 46.6 months (range: 3 - 157 months), 4 of 78 patients (5.1%) developed high-grade (RTOG Grade 3 and 4) late toxicity: 3 patients (3.8%) experienced sensory deficits without motor deficits, none had any limitations of daily activities. One patient (1.2%) developed motor deficit with loss of motor function of one upper extremity. The only patient, who developed permanent motor damage had received additional prior radiation treatment and therefore received a cumulative spinal cord dose higher than the treatment guidelines. No patient treated within the guidelines experienced any motor impairment. Six patients (7.7%) experienced transient Lhermitt's syndrome and 1 patient (1.2%) developed asymptomatic radiographic MR findings only. Time to onset of symptoms of radiographic

Breast tomography with synchrotron radiation: preliminary results

International Nuclear Information System (INIS)

Pani, Silvia; Longo, Renata; Dreossi, Diego; Montanari, Francesco; Olivo, Alessandro; Arfelli, Fulvia; Bergamaschi, Anna; Poropat, Paolo; Rigon, Luigi; Zanconati, Fabrizio; Palma, Ludovico Dalla; Castelli, Edoardo

2004-01-01

A system for in vivo breast imaging with monochromatic x-rays has been designed and built at the synchrotron radiation facility Elettra in Trieste (Italy) and will be operational in 2004. The system design involves the possibility of performing both planar mammography and breast tomography. In the present work, the first results obtained with a test set-up for breast tomography are shown and discussed. Tomographic images of in vitro breasts were acquired using monochromatic x-ray beams in the energy range 20-28 keV and a linear array silicon pixel detector. Tomograms were reconstructed using standard filtered backprojection algorithms; the effect of different filters was evaluated. The attenuation coefficients of fibroglandular and adipose tissue were measured, and a quantitative comparison of images acquired at different energies was performed by calculating the differential signal-to-noise ratio of fibroglandular details in adipose tissue. All images required a dose comparable to the dose delivered in clinical, conventional mammography and showed a high resolution of the breast structures without the overlapping effects that limit the visibility of the structures in 2D mammography. A quantitative evaluation of the images proves that the image quality at a given dose increases in the considered energy range and for the considered breast sizes

Feasibility of dual-energy computed tomography in radiation therapy planning

Science.gov (United States)

Sheen, Heesoon; Shin, Han-Back; Cho, Sungkoo; Cho, Junsang; Han, Youngyih

2017-12-01

In this study, the noise level, effective atomic number ( Z eff), accuracy of the computed tomography (CT) number, and the CT number to the relative electron density EDconversion curve were estimated for virtual monochromatic energy and polychromatic energy. These values were compared to the theoretically predicted values to investigate the feasibility of the use of dual-energy CT in routine radiation therapy planning. The accuracies of the parameters were within the range of acceptability. These results can serve as a stepping stone toward the routine use of dual-energy CT in radiotherapy planning.

Risk management of radiation therapy. Survey by north Japan radiation therapy oncology group

International Nuclear Information System (INIS)

Aoki, Masahiko; Abe, Yoshinao; Yamada, Shogo; Hareyama, Masato; Nakamura, Ryuji; Sugita, Tadashi; Miyano, Takashi

2004-01-01

A North Japan Radiation Oncology Group (NJRTOG) survey was carried out to disclose the risk management of radiation therapy. During April 2002, we sent questionnaires to radiation therapy facilities in northern Japan. There were 31 replies from 27 facilities. Many incidents and accidents were reported, including old cases. Although 60% of facilities had a risk management manual and/or risk manager, only 20% had risk management manuals for radiation therapy. Eighty five percent of radiation oncologists thought that incidents may be due to a lack of manpower. Ninety percent of radiation oncologists want to know the type of cases happened in other facilities. The risk management system is still insufficient for radiation therapy. We hope that our data will be a great help to develop risk management strategies for radiation therapy for all radiation oncologists in Japan. (author)

Quantifying metal artefact reduction using virtual monochromatic dual-layer detector spectral CT imaging in unilateral and bilateral total hip prostheses

NARCIS (Netherlands)

Wellenberg, R. H. H.; Boomsma, M. F.; van Osch, J. A. C.; Vlassenbroek, A.; Milles, J.; Edens, M. A.; Streekstra, G. J.; Slump, C. H.; Maas, M.

2017-01-01

To quantify the impact of prosthesis material and design on the reduction of metal artefacts in total hip arthroplasties using virtual monochromatic dual-layer detector Spectral CT imaging. The water-filled total hip arthroplasty phantom was scanned on a novel 128-slice Philips IQon dual-layer

Rapid determination of trace phosphorus, sulfur, chlorine, bromine and iodine by energy dispersive X-ray fluorescence analysis with monochromatic excitations

International Nuclear Information System (INIS)

Wakisaka, Tatsushi; Morita, Naoki; Hirabayashi, Tadashi; Nakahara, Taketoshi

1998-01-01

A useful and rapid procedure is described for the determination of trace phosphorus, sulfur, chlorine, bromine, and iodine by means of an energy dispersive X-ray fluorescence spectrometer (EDXRF) with monochromatic excitations. Using monochromatic excitations, the detection limits for phosphorus, sulfur, chlorine (Cr-Kα, 5.41 keV), bromine (Mo-Kα, 17.44 keV), and iodine (W-continuum, 40 keV) were found to be 4.6, 1.7, 0.7, 0.09 and 0.5 μg g -1 , respectively. The relative standard deviations in five replicate measurements were 0.9-1.3%. The proposed method was applied to the direct determination of sulfur in the NIST Residual Fuel Oil, and others. The results obtained by the proposed method were in good agreement with the certified values. Bromine in a seawater sample, as well as iodine and bromine in a brine sample were determined by the proposed method. The obtained results were in good agreement with those obtained by ion chromatography. (author)

Determination, through of thermoluminescence dosimetry, of the incident radiation in critical organs, during cephalometric radiographies

International Nuclear Information System (INIS)

Hipolito Junior, O. di; Goncalves, N.; Boscolo, F.N.; Montebelo Filho, A.

1985-01-01

The object of this paper was to value and to compare the doses of X-ray incident in critical orgas of patient and operator, during cephalometric radiography. Each patient was submited for two radiographics expositions. First of all, they use the followings factors: 85 kVp, 15 mA and 4/10 s of exposition; while of the second radiography the conditions were of 70 kVp, 15 mA and 1.2 s of exposition. The dosimetric method was the thermoluminescent through the LiF-700. Although the cephalometric radiographies showed similars qualities, in bot conditions where the equipment functioned, the situation of high voltage was noted small doses of radiation. (author) [pt

Intravenous coronary angiography using the orbital radiation

Energy Technology Data Exchange (ETDEWEB)

Ohtsuka, Sadanori; Yamaguchi, Iwao; Wu, Jin; Takeda, Toru; Itai, Yuji; Maruhashi, Akira [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Hyodo, Kazuyuki; Ando, Masami [High Energy Accelerator Research Org., Tsukuba, Ibaraki (Japan). Inst. of Materials Structure Science

2002-09-01

This review described the progress and current status of intravenous coronary angiography (IVCAG) using the orbital radiation generated by the synchrotron. Authors diagnosed 4 patients of coronary artery disease in 1996 and 33 until 2000. Monochromatic 2-D X-ray beam (2.0 X 10{sup 10} photons/mm{sup 2}/sec, 130 X 75 mm) of 37 keV was obtained by non-symmetrical reflection of synchrotron radiation generated by 5.0 GeV accelerated electron. The use of 2-D beam enabled to give the dynamic IVCAG image in contrast with the static image by the 1-D slit beam. Intermittent irradiation (5 msec/100 msec) reduced the exposure dose to <750 mSv. Images were recorded in the Sony digital video-recorder placed behind the Sony Charge-coupled device (CCD) camera and Toshiba photo-multiplier, and gave the precision of 1 mm of the artery. The IVCAG by synchrotron radiation reduced patients' burden and was expected to be more widely used in future. (K.H.)

Spectral CT with monochromatic imaging and metal artifacts reduction software for artifacts reduction of ¹²⁵I radioactive seeds in liver brachytherapy.

Science.gov (United States)

Yang, Qiuxia; Peng, Sheng; Wu, Jing; Ban, Xiaohua; He, Mingyan; Xie, Chuanmiao; Zhang, Rong

2015-11-01

To investigate the optimal monochromatic energy for artifacts reduction from (125)I seeds as well as image improvement in the vicinity of seeds on monochromatic images with and without metal artifacts reduction software (MARS) and to compare this with traditional 120-kVp images, so as to evaluate the application value of gemstone spectral imaging for reducing artifacts from (125)I seeds in liver brachytherapy. A total of 45 tumors from 25 patients treated with (125)I seed brachytherapy in the liver were enrolled in this study. Multiphasic spectral computed tomography (CT) scanning was performed for each patient. After a delay time of 15 s of portal vein phase, a traditional 120-kVp scan was performed, focusing on several planes of (125)I seeds only. The artifact index (AI) in the vicinity of seeds and the standard deviation (SD) of the CT density of region of interest in the outside liver parenchyma were calculated. Artifact appearance was evaluated and classified on reconstructed monochromatic S and 120-kVp images. Image quality in the vicinity of seeds of three data sets were evaluated using a 1-5 scale scoring method. The Friedman rank-sum test was used to estimate the scoring results of image quality. The greatest noise in monochromatic images was found at 40 keV (SD = 27.38, AI = 206.40). The optimal monochromatic energy was found at 75 keV, which provided almost the least image noise (SD = 10.01) and good performance in artifact reduction (AI = 102.73). Image noise and AI reduction at 75 keV was decreased by 63.44 and 50.23%, compared with at 40 keV. Near-field thick artifacts were obvious in all 45 lesions, in 120-kVp images, and 75-keV images, but basically reduced in 75 keV MARS images and artifacts completely invisible in 7 lesions. The number of diagnosable images (score ≥3) was significantly more in the 75-keV MARS group (28/45), and the 75-keV group (22/45) than in the 120-kVp group (11/45) (p improve image quality, even to a state of being

Interstrand DNA crosslinking by 4,5',8-trimethylpsoralen plus monochromatic ultraviolet light

International Nuclear Information System (INIS)

Cohen, L.F.; Ewig, R.A.G.; Kohn, K.W.; Glaubiger, D.

1980-01-01

DNA crosslinking by 4,5',8-trimethylpsoralen plus monochromatic ultraviolet light of wavelength 365 nm was studied in mouse L1210 leukemia cells. DNA breaks and crosslinking were evaluated by alkaline elution of DNA from poly(vinyl chloride) filters. Trimethylpsoralen plus 365 nm light produced DNA crosslinks but not breaks. The kinetics of crosslinging were linear with respect to concentration and second-order with respect to light exposure time. The latter finding supports the proposed two photon mechanism for the formation of diadducts. In contrast to DNA crosslinking agents such as nitrogen mustard, nitrosoureas and platinums, trimethylpsoralen crosslinks were resistant to proteolytic digestion. Thus, trimethylpsoralen plus 365 nm light produced interstrand crosslinks, as proposed for a bifunctional agent binding to bases on opposite DNA strands. (Auth.)

Cancer incidence among Nordic airline cabin crew.

Science.gov (United States)

Pukkala, Eero; Helminen, Mika; Haldorsen, Tor; Hammar, Niklas; Kojo, Katja; Linnersjö, Anette; Rafnsson, Vilhjálmur; Tulinius, Hrafn; Tveten, Ulf; Auvinen, Anssi

2012-12-15

Airline cabin crew are occupationally exposed to cosmic radiation and jet lag with potential disruption of circadian rhythms. This study assesses the influence of work-related factors in cancer incidence of cabin crew members. A cohort of 8,507 female and 1,559 male airline cabin attendants from Finland, Iceland, Norway and Sweden was followed for cancer incidence for a mean follow-up time of 23.6 years through the national cancer registries. Standardized incidence ratios (SIRs) were defined as ratios of observed and expected numbers of cases. A case-control study nested in the cohort (excluding Norway) was conducted to assess the relation between the estimated cumulative cosmic radiation dose and cumulative number of flights crossing six time zones (indicator of circadian disruption) and cancer risk. Analysis of breast cancer was adjusted for parity and age at first live birth. Among female cabin crew, a significantly increased incidence was observed for breast cancer [SIR 1.50, 95% confidence interval (95% CI) 1.32-1.69], leukemia (1.89, 95% CI 1.03-3.17) and skin melanoma (1.85, 95% CI 1.41-2.38). Among men, significant excesses in skin melanoma (3.00, 95% CI 1.78-4.74), nonmelanoma skin cancer (2.47, 95% CI 1.18-4.53), Kaposi sarcoma (86.0, 95% CI 41.2-158) and alcohol-related cancers (combined SIR 3.12, 95% CI 1.95-4.72) were found. This large study with complete follow-up and comprehensive cancer incidence data shows an increased incidence of several cancers, but according to the case-control analysis, excesses appear not to be related to the cosmic radiation or circadian disruptions from crossing multiple time zones. Copyright © 2012 UICC.

Incidence of thyroid carcinoma in patients with Hashimoto's thyroiditis and solitary cold nodules

International Nuclear Information System (INIS)

Ott, R.A.; Calandra, D.B.; McCall, A.; Shah, K.H.; Lawrence, A.M.; Paloyan, E.

1985-01-01

The reported incidence of thyroid carcinoma in Hashimoto's thyroiditis varies widely. For this reason the specific subpopulation of patients with Hashimoto's thyroiditis and a solitary cold nodule was analyzed. Between 1972 and 1984 we operated on 146 consecutive patients with solitary cold nodules and Hashimoto's thyroiditis. There were 47 carcinomas, for an incidence of 32%. The mean age of the 146 patients was 43 1/2 years (median 44 years), with 126 females and 20 males. There was a history of prior head and neck radiation exposure in 54 patients, with a 33% incidence of thyroid carcinoma. The 92 patients without a history of radiation exposure had a 31.5% incidence of carcinoma. The frequency of multicentricity (bilateralism) was 33% in the group that underwent radiation and 24% in the group that did not. To date, with a mean follow-up of 4.7 years, there have been no deaths and no evidence of recurrence. In conclusion, we report a 32% incidence of thyroid carcinoma in patients with Hashimoto's thyroiditis and a solitary cold nodule, with no apparent difference between the patients with or without a history of radiation exposure, although there was a higher incidence of bilateralism (33% versus 24%) in the carcinomas of the patients with a history of head and neck irradiation. We suggest that the operative management of these patients is total thyroidectomy for those with a history of head and neck radiation and thyroid lobectomy for patients with no history of radiation, followed by contralateral lobectomy if a carcinoma is demonstrated

Radiological Cs-137 accidents/incidents in Estonia

International Nuclear Information System (INIS)

Sinisso, Mark

1997-01-01

Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

Radiological Cs-137 accidents/incidents in Estonia

Energy Technology Data Exchange (ETDEWEB)

Sinisso, Mark [Ministry of Foreign Affairs, Tallin (Estonia)

1997-12-31

Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

Acoustic manipulation of active spherical carriers: Generation of negative radiation force

Energy Technology Data Exchange (ETDEWEB)

Rajabi, Majid, E-mail: majid_rajabi@iust.ac.ir; Mojahed, Alireza

2016-09-15

This paper examines theoretically a novel mechanism of generating negative (pulling) radiation force for acoustic manipulation of spherical carriers equipped with piezoelectric actuators in its inner surface. In this mechanism, the spherical particle is handled by common plane progressive monochromatic acoustic waves instead of zero-/higher- order Bessel beams or standing waves field. The handling strategy is based on applying a spatially uniform harmonic electrical voltage at the piezoelectric actuator with the same frequency of handling acoustic waves, in order to change the radiation force effect from repulsive (away from source) to attractive (toward source). This study may be considered as a start point for development of contact-free precise handling and entrapment technology of active carriers which are essential in many engineering and medicine applications.

Multiple energy computed tomography with monochromatic x rays from the NSLS

International Nuclear Information System (INIS)

Dilmanian, F.A.; Nachaliel, E.; Garrett, R.F.; Thomlinson, W.C.; Chapman, L.D.; Moulin, H.R.; Oversluizen, T.; Rarback, H.M.; Rivers, M.; Spanne, P.; Thompson, A.C.; Zeman, H.D.

1991-01-01

We used monochromatic x rays from the X17 superconducting wiggler beamline at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, for dual-energy quantitative computed tomography (CT) of a 27 mm-diameter phantom containing solutions of different KOH concentrations in cylindrical holes of 5-mm diameter. The CT configuration was a fixed horizontal fan-shaped beam of 1.5 mm height and 30 mm width, and a subject rotating around a vertical axis. The transmitted x rays were detected by a linear-array Si(Li) detector with 120 elements of 0.25 mm width each. We used a two-crystal Bragg-Bragg fixed-exit monochromator with Si crystals. Dual photon absorptiometry (DPA) CT data were taken at 20 and 38 keV. The reconstructed phantom images show the potential of the system for quantitative CT

Nitrogen capillary plasma as a source of intense monochromatic radiation at 2.88 nm

Czech Academy of Sciences Publication Activity Database

Vrba, Pavel; Vrbová, M.; Zakharov, S.V.; Zakharov, V.S.; Jančárek, A.; Nevrkla, M.

2014-01-01

Roč. 196, October (2014), s. 24-30 ISSN 0368-2048 R&D Projects: GA ČR GAP102/12/2043; GA MŠk(CZ) LG13029 Grant - others:GA MŠk(CZ) CZ.1.07/2.3.00/20.0092 Institutional support: RVO:61389021 Keywords : Capillary Z-pinch * Water window radiation source * RHMD Code Z* Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.436, year: 2014 http://dx.doi.org/10.1016/j.elspec.2013.12.015

[Skin cancer incidence in Zacatecas].

Science.gov (United States)

Pinedo-Vega, José Luis; Castañeda-López, Rosalba; Dávila-Rangel, J Ignacio; Mireles-García, Fernando; Ríos-Martínez, Carlos; López-Saucedo, Adrián

2014-01-01

Skin cancer is the most frequent cancer related to ultraviolet radiation. The aim was to estimate the incidence of skin cancer type, melanoma and non-melanoma in Zacatecas, Mexico. An epidemiological study was carried out during the period from 2008 to 2012. The data were obtained from the Instituto Mexicano del Seguro Social (IMSS), Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE), Secretaría de Salud de Zacatecas (SSZ) and a private source, the Centro Médico Alameda. The incidence and the global prevalence were estimated. We studied 958 skin cancer cases, histopathologically confirmed. The cases were distributed as: 63.6 % basal cell carcinomas, 25.8 % squamous cell carcinomas, and 10.6 % melanoma. Significantly higher proportions were observed in women in the basal cell carcinomas (60.4 %) and squamous cell carcinomas (53.4 %). However, in the case of melanoma, the major proportion was observed in men (55.9 %). The more frequent skin cancer location was the face and for basal cell carcinoma was the nose (53 %); for squamous cell carcinomas were the lips (36 %), and for melanoma it was also the nose (40 %). The skin cancer incidence was estimated in 20 cases for each 100 000 inhabitants. Linear regression analysis showed that the skin cancer is increasing at an annual rate of 10.5 %. The anatomical location indicates that solar UV radiation is a risk factor, since the face is the zone with major exposure to solar radiation.

Dual Energy CT (DECT) Monochromatic Imaging: Added Value of Adaptive Statistical Iterative Reconstructions (ASIR) in Portal Venography.

Science.gov (United States)

Zhao, Liqin; Winklhofer, Sebastian; Jiang, Rong; Wang, Xinlian; He, Wen

2016-01-01

To investigate the effect of the adaptive statistical iterative reconstructions (ASIR) on image quality in portal venography by dual energy CT (DECT) imaging. DECT scans of 45 cirrhotic patients obtained in the portal venous phase were analyzed. Monochromatic images at 70keV were reconstructed with the following 4 ASIR percentages: 0%, 30%, 50%, and 70%. The image noise (IN) (standard deviation, SD) of portal vein (PV), the contrast-to-noise-ratio (CNR), and the subjective score for the sharpness of PV boundaries, and the diagnostic acceptability (DA) were obtained. The IN, CNR, and the subjective scores were compared among the four ASIR groups. The IN (in HU) of PV (10.05±3.14, 9.23±3.05, 8.44±2.95 and 7.83±2.90) decreased and CNR values of PV (8.04±3.32, 8.95±3.63, 9.80±4.12 and 10.74±4.73) increased with the increase in ASIR percentage (0%, 30%, 50%, and 70%, respectively), and were statistically different for the 4 ASIR groups (pASIR percentages (pASIR (pASIR addition in DECT portal venography could improve the 70 keV monochromatic image quality.

Note: Diagnosing femtosecond laser-solid interactions with monochromatic Kα imager and x-ray pinhole camera

International Nuclear Information System (INIS)

Lin, X. X.; Li, Y. T.; Liu, F.; Du, F.; Wang, S. J.; Chen, L. M.; Zhang, L.; Zheng, Y.; Liu, X.; Liu, X. L.; Wang, Z. H.; Ma, J. L.; Wei, Z. Y.; Liu, B. C.; Zhang, J.

2011-01-01

An x-ray pinhole camera and a monochromatic K α imager are used to measure the interactions of intense femtosecond laser pulses with Cu foil targets. The two diagnostics give different features in the spot size and the laser energy scaling, which are resulted from different physical processes. Under our experimental conditons, the K α emission is mainly excited by the fast electrons transporting inside the cold bulk target. In contrast, the x-ray pinhole signals are dominated by the broadband thermal x-ray emission from the hot plasma at the front target surface.

Correlation between the time-series of air temperature and incident solar radiation at Port Harcourt, Nigeria

International Nuclear Information System (INIS)

Adjepong, S.K.; Okujagu, C.

1987-12-01

We present the preliminary results of an investigation of the correlation between the temporal variations of the time-series of ground air temperature and incident solar radiation recorded at Port Harcourt (lat. 4 deg. 51' N, long. 7 deg. 01' E), Nigeria, during a five-year period (1981 through 1985). Computed cross-correlation functions of the daily time-series reveal correlation at time lags which are approximate harmonics of the 27-day solar rotation cycle. The cross-correlation function of the mean monthly series shows correlation at a time lag of 12 months implying a dominant annual-cycle component in the variation of either series. (author). 12 refs, 2 figs

Radiological incidents in industrial gamma radiography in the Philippines, 1979-1993

International Nuclear Information System (INIS)

Borras, A.M.

1994-01-01

Among the many practices of radiation sources, the practice of industrial gamma radiography in the country has the most number of reported radiological incidents. During the past fourteen (14) years, from 1979-1993, twenty (20) incidents that have occurred were reported to the Institute. This paper presents the nature and extent of the 20 reported incidents as well as the results of the analysis of why these incidents happened. The results of the analysis showed that the causes of these incidents are mainly human error and equipment failure. Hence, the factors that can minimize or prevent the chance of occurrence and/or recurrence of incidents and in minimizing the hazard in case of radiological incidents are: a) proper training and re-training of personnel; b) proper and regular inspection and maintenance of equipment; c) adequate radiation survey; and d) proper storage and inventory of the radiography sealed sources. (author). 3 refs.; 5 figs.; 1 tab

Calibration of photographic dosemeters to evaluate the personal equivalent dose, Hp (10), irradiated by different radiation qualities and angles of incidence

International Nuclear Information System (INIS)

Santoro, Christiana; Antonio Filho, Joao

2013-01-01

To use radiation detectors, should periodically perform tests and calibrations on instruments in order to verify its good functionality. One way to ascertain the quality of the instrument is to conduct a study of the angular dependence of the response of the radiation detectors. The photographic dosimetry has been used widely to quantify the radiation doses and to estimate levels of doses received by workers involved with X-and gamma radiation. Photographic dosimeters are used because provide wide range of exposure and good accuracy. One of the sources of error have been introduced by different irradiation geometries between calibration and measurement in radiation fields used in x-ray and gamma ray sources, therefore, there is a need for an evaluation of the sensitivity of dosimeters with variation of the angle of the incident beam. In this study were tested 190 photographic dosemeters in the Metrology Laboratory of the Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) using the phantom H p (10), where the dosimeters are evaluated on the basis of the new operational magnitude for individual monitoring, the equivalent personal dose, H p (10). Angular dependence of these radiation detectors was studied in X radiation fields (in the range of 45 keV energy to 164 keV) and gamma radiation ( 137 Cs-662 keV e 60 Co - 1250 keV)

Free-Free Transitions in the Presence of Laser Fields at Very Low Incident Electron Energy

Science.gov (United States)

Bhatia, A. K.; Sinha, Chandana

2010-01-01

We study the free-free transition in electron-hydrogenic systems in ground state in presence of an external laser field at very loud incident energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen to be monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser in a nonperturbative manner by choosing a Volkov wave function for it. The scattering weave function for the electron is solved numerically by taking into account the effect of the electron exchange, short-range as well as of the long-range interactions to get the S and P wave phase shifts while for the higher angular momentum phase shifts the exchange approximation has only been considered. We calculate the laser assisted differential cross sections (LADCS) for the aforesaid free-free transition process for single photon absorption/emission. The laser intensity is chosen to be much less than the atomic field intensity. A strong suppression is noted in the LADCS as compared to the field free (FF) cross sections. Unlike the FF ones, the LADCS exhibit some oscillations having a distinct maximum at a low value of the scattering angle depending on the laser parameters as well as on the incident energies.

Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media

Science.gov (United States)

Stamnes, Knut; Tsay, S.-CHEE; Jayaweera, Kolf; Wiscombe, Warren

1988-01-01

The transfer of monochromatic radiation in a scattering, absorbing, and emitting plane-parallel medium with a specified bidirectional reflectivity at the lower boundary is considered. The equations and boundary conditions are summarized. The numerical implementation of the theory is discussed with attention given to the reliable and efficient computation of eigenvalues and eigenvectors. Ways of avoiding fatal overflows and ill-conditioning in the matrix inversion needed to determine the integration constants are also presented.

Effective beam method for element concentrations

International Nuclear Information System (INIS)

Tolhurst, Thomas; Barbi, Mauricio; Tokaryk, Tim

2015-01-01

A method to evaluate chemical element concentrations in samples by generating an effective polychromatic beam using as initial input real monochromatic beam data is presented. There is a great diversity of research being conducted at synchrotron facilities around the world and a diverse set of beamlines to accommodate this research. Time is a precious commodity at synchrotron facilities; therefore, methods that can maximize the time spent collecting data are of value. At the same time the incident radiation spectrum, necessary for some research, may not be known on a given beamline. A preliminary presentation of a method applicable to X-ray fluorescence spectrocopic analyses that overcomes the lack of information about the incident beam spectrum that addresses both of these concerns is given here. The method is equally applicable for other X-ray sources so long as local conditions are considered. It relies on replacing the polychromatic spectrum in a standard fundamental parameters analysis with a set of effective monochromatic photon beams. A beam is associated with each element and can be described by an analytical function allowing extension to elements not included in the necessary calibration measurement(s)

X-ray resonant Raman scattering cross sections of Mn, Fe, Cu and Zn

International Nuclear Information System (INIS)

Sanchez, Hector Jorge; Valentinuzzi, MarIa Cecilia; Perez, Carlos

2006-01-01

X-ray fluorescence spectra present singular characteristics produced by the different scattering processes. When atoms are irradiated with incident energy lower and close to an absorption edge, scattering peaks appear due to an inelastic process known as resonant Raman scattering. It constitutes an important contribution to the background of the fluorescent line. The resonant Raman scattering must be taken into account in the determination of low concentration contaminants, especially when the elements have proximate atomic numbers. The values of the mass attenuation coefficients experimentally obtained when materials are analysed with monochromatic x-ray beams under resonant conditions differ from the theoretical values (between 5% and 10%). This difference is due, in part, to the resonant Raman scattering. Monochromatic synchrotron radiation was used to study the Raman effect on pure samples of Mn, Fe, Cu and Zn. Energy scans were carried out in different ranges of energy near the absorption edge of the target element. As the Raman peak has a non-symmetric shape, theoretical models for the differential cross section, convoluted with the instrument function, were used to determine the RRS cross section as a function of the incident energy

A Study on the Interaction Mechanism between Thermal Radiation and Materials

Institute of Scientific and Technical Information of China (English)

Dehong XIA; Tao YU; Chuangu WU; Qingqing CHANG; Honglei JIAO

2005-01-01

From the viewpoint of field synergy principle and dipole radiation theory, the interaction between the incident thermal radiation wave and materials is analyzed to reveal the mechanism of selective absorption of incident thermal radiation. It is shown that the frequency of the incident thermal radiation and the damping constant of damping oscillators in materials are of vital importance for the thermal radiation properties (reflectivity, absorptivity, transmissivity, etc.) of materials.

Incidence of radiation pneumonitis after thoracic irradiation: Dose-volume correlates

International Nuclear Information System (INIS)

Schallenkamp, John M.; Miller, Robert C.; Brinkmann, Debra H.; Foote, Tyler; Garces, Yolanda I.

2007-01-01

Purpose: To define clinical and dosimetric parameters correlated with the risk of clinically relevant radiation pneumonitis (RP) after thoracic radiotherapy. Methods and Materials: Records of consecutive patients treated with definitive thoracic radiotherapy were retrospectively reviewed for the incidence of RP of Grade 2 or greater by the Common Toxicity Criteria. Dose-volume histograms using total lung volume (TL) and TL minus gross tumor volume (TL-G) were created with and without heterogeneity corrections. Mean lung dose (MLD), effective lung volume (V eff ), and percentage of TL or TL-G receiving greater than or equal to 10, 13, 15, 20, and 30 Gy (V10-V30, respectively) were analyzed by logistic regression. Receiver operating characteristic (ROC) curves were generated to estimate RP predictive values. Results: Twelve cases of RP were identified in 92 eligible patients. Mean lung dose, V10, V13, V15, V20, and V eff were significantly correlated to RP. Combinations of MLD, V eff , V20, and V30 lost significance using TL-G and heterogeneity corrections. Receiver operating characteristic analysis determined V10 and V13 as the best predictors of RP risk, with a decrease in predictive value above those volumes. Conclusions: Intrathoracic radiotherapy should be planned with caution when using radiotherapy techniques delivering doses of 10 to 15 Gy to large lung volumes

Radiological incident preparedness for community hospitals: a demonstration project.

Science.gov (United States)

Jafari, Mary Ellen

2010-08-01

In November 2007, the Wisconsin Division of Public Health Hospital Disaster Preparedness Program State Expert Panel on Radiation Emergencies issued a report titled The Management of Patients in a Radiological Incident. Gundersen Lutheran Health System was selected to conduct a demonstration project to implement the recommendations in that report. A comprehensive radiological incident response plan was developed and implemented in the hospital's Trauma and Emergency Center, including the purchase and installation of radiation detection and identification equipment, staff education and training, a tabletop exercise, and three mock incident test exercises. The project demonstrated that the State Expert Panel report provides a flexible template that can be implemented at community hospitals using existing staff for an approximate cost of $25,000.

Mark IV 'Grasshopper' grazing incidence mono-chromator for the Canadian Synchrotron Radiation Facility (CSRF)

International Nuclear Information System (INIS)

Tan, K.H.; Bancroft, G.M.; Coatsworth, L.L.; Yates, B.W.

1982-01-01

The vacuum, mechanical, and optical characteristics of a 'Grasshopper' grazing incidence monochromator for use with a synchrotron radiation source in the 30-300 eV range is described. The monochromator is compatible with ultrahigh vacuum ( -10 Torr throughout), and the motor driven scan mechanism is linear and reliable. The monchromator has been calibrated using several known absorption edges between 36 and 102 eV and a nonlinear least squares fit to the scan equation. These same absorption edges, plus a scan over zero order, show that the present resolution of the monochromator (with 10 and 16 μm exit and entrance slits respectively) is 0.16 A (0.06 eV at the AlLsub(2,3) edge). With 10 μm entrance and exit slits the resolution will be very close to the theoretical Δlambda = 0.083 A

Measurement of K-line transition rates for Ti, V, Cr, Mn, Fe and Co using synchrotron radiation

International Nuclear Information System (INIS)

Carreras, A.; Stutz, G.; Castellano, G.

2003-01-01

Transition rates were obtained from spectra for pure metallic samples of atomic number ranging from 22 to 27, measured with monochromatic incident X-ray beams from a synchrotron source. The experimental setup for this consisted of an energy dispersive spectrometer in a conventional 45-45 deg. geometry, mounted in an evacuated chamber. Absorption, detector efficiency and multiple scattering were taken into account. The results obtained are compared with recent theoretical and experimental data as well as with the well-known theoretical predictions from Scofield

Measurement of K-line transition rates for Ti, V, Cr, Mn, Fe and Co using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Carreras, A. E-mail: alejo@quechua.fis.uncor.edu; Stutz, G.; Castellano, G

2003-08-01

Transition rates were obtained from spectra for pure metallic samples of atomic number ranging from 22 to 27, measured with monochromatic incident X-ray beams from a synchrotron source. The experimental setup for this consisted of an energy dispersive spectrometer in a conventional 45-45 deg. geometry, mounted in an evacuated chamber. Absorption, detector efficiency and multiple scattering were taken into account. The results obtained are compared with recent theoretical and experimental data as well as with the well-known theoretical predictions from Scofield.

Acoustic radiation force control: Pulsating spherical carriers.

Science.gov (United States)

Rajabi, Majid; Mojahed, Alireza

2018-02-01

The interaction between harmonic plane progressive acoustic beams and a pulsating spherical radiator is studied. The acoustic radiation force function exerted on the spherical body is derived as a function of the incident wave pressure and the monopole vibration characteristics (i.e., amplitude and phase) of the body. Two distinct strategies are presented in order to alter the radiation force effects (i.e., pushing and pulling states) by changing its magnitude and direction. In the first strategy, an incident wave field with known amplitude and phase is considered. It is analytically shown that the zero- radiation force state (i.e., radiation force function cancellation) is achievable for specific pulsation characteristics belong to a frequency-dependent straight line equation in the plane of real-imaginary components (i.e., Nyquist Plane) of prescribed surface displacement. It is illustrated that these characteristic lines divide the mentioned displacement plane into two regions of positive (i.e., pushing) and negative (i.e., pulling) radiation forces. In the second strategy, the zero, negative and positive states of radiation force are obtained through adjusting the incident wave field characteristics (i.e., amplitude and phase) which insonifies the radiator with prescribed pulsation characteristics. It is proved that zero radiation force state occurs for incident wave pressure characteristics belong to specific frequency-dependent circles in Nyquist plane of incident wave pressure. These characteristic circles divide the Nyquist plane into two distinct regions corresponding to positive (out of circles) and negative (in the circles) values of radiation force function. It is analytically shown that the maximum amplitude of negative radiation force is exactly equal to the amplitude of the (positive) radiation force exerted upon the sphere in the passive state, by the same incident field. The developed concepts are much more deepened by considering the required

X-ray Laue diffraction with allowance for second derivatives of amplitudes in dynamical diffraction equations

International Nuclear Information System (INIS)

Balyan, M.K.

2014-01-01

Asymmetrical Laue diffraction in a perfect crystal with a plane entrance surface is considered. The second derivatives of amplitudes in the direction, perpendicular to diffraction plane in the dynamical diffraction equations are taken into account. Using the corresponding Green function a general form for the amplitude of diffracted wave in the crystal is derived. The sizes of the source in both directions as well as the source of crystal distance and non-monochromaticity of the radiation incident on the crystal are taken into account. On the basis of obtained expression the coherent properties of the field depending on the sizes of the source and on the width of the spectrum of the incident radiation are analyzed. Taking into account the second derivatives of amplitudes with respect to the direction, perpendicular to the diffraction plane, the time dependent propagation equations for an X-ray pulse in a perfect crystal are given

MO-F-CAMPUS-J-01: Effect of Iodine Contrast Agent Concentration On Cerebrovascular Dose for Synchrotron Radiation Microangiography Based On a Simple Mouse Head Model and a Voxel Mouse Head Phantom

Energy Technology Data Exchange (ETDEWEB)

Lin, H; Jing, J; Xie, C [Hefei University of Technology, Hefei (China); Lu, Y [Shanghai Jiao Tong University, Shanghai (China)

2015-06-15

Purpose: To find effective setting methods to mitigate the irradiation injure in synchrotron radiation microangiography(SRA) by Monte Carlo simulation. Methods: A mouse 1-D head model and a segmented voxel mouse head phantom were simulated by EGSnrc/Dosxyznrc code to investigate the dose enhancement effect of the iodine contrast agent irradiated by a monochromatic synchrotron radiation(SR) source. The influence of, like iodine concentration (IC), vessel width and depth, with and without skull layer protection and the various incident X ray energies, were simulated. The dose enhancement effect and the absolute dose based on the segmented voxel mouse head phantom were evaluated. Results: The dose enhancement ratio depends little on the irradiation depth, but strongly on the IC, which is linearly increases with IC. The skull layer protection cannot be ignored in SRA, the 700µm thick skull could decrease 10% of the dose. The incident X-ray energy can significantly affact the dose. E.g. compared to the dose of 33.2keV for 50mgI/ml, the 32.7keV dose decreases 38%, whereas the dose of 33.7 keV increases 69.2%, and the variation will strengthen more with enhanced IC. The segmented voxel mouse head phantom also showed that the average dose enhancement effect and the maximal voxel dose per photon depends little on the iodine voxel volume ratio, but strongly on IC. Conclusion: To decrease dose damage in SRA, the high-Z contrast agent should be used as little as possible, and try to avoid radiating locally the injected position immediately after the contrast agent injection. The fragile vessel containing iodine should avoid closely irradiating. Avoiding irradiating through the no or thin skull region, or appending thin equivalent material from outside to protect is also a better method. As long as SRA image quality is ensured, using incident X-ray energy as low as possible.

Photofission of {sup NAT} Pt by monochromatic and polarized photons in the quasi-deuteron region; Fotofissao da {sup NAT} Pt por fotons monocromaticos e polarizados na regiao do quase-deuteron

Energy Technology Data Exchange (ETDEWEB)

Paiva, Eduardo de

1992-01-01

The measurement of the Nat Pt photofission yield at 69 MeV of effective average energy of the incident photon is made using a polarized and monochromatic photon beam from the LADON system of the National Laboratory of Frascati, Italy, produced by inverse Compton scattering of laser light by high energy electrons of the ADONE Accelerator and using as fission track solid detector the Makrofol, being the developing made by usual procedure. The experimental value of the nuclear fissionability is compared to a theoretical value obtained following a model at two stages: in the first, the photon energy is absorbed by a neutron-proton pair inducing to the nucleus excitation, and in the second the nucleus de-excites due to the competition between nucleon evaporation and fission. The effect of fast nucleon emission during the first stage and the successive evaporation of neutrons in the second stage are considered. 40 refs, 12 figs, 9 tabs.

Ambient ultraviolet radiation exposure and hepatocellular carcinoma incidence in the United States.

Science.gov (United States)

VoPham, Trang; Bertrand, Kimberly A; Yuan, Jian-Min; Tamimi, Rulla M; Hart, Jaime E; Laden, Francine

2017-08-18

Hepatocellular carcinoma (HCC), the most commonly occurring type of primary liver cancer, has been increasing in incidence worldwide. Vitamin D, acquired from sunlight exposure, diet, and dietary supplements, has been hypothesized to impact hepatocarcinogenesis. However, previous epidemiologic studies examining the associations between dietary and serum vitamin D reported mixed results. The purpose of this study was to examine the association between ambient ultraviolet (UV) radiation exposure and HCC risk in the U.S. The Surveillance, Epidemiology, and End Results (SEER) database provided information on HCC cases diagnosed between 2000 and 2014 from 16 population-based cancer registries across the U.S. Ambient UV exposure was estimated by linking the SEER county with a spatiotemporal UV exposure model using a geographic information system. Poisson regression with robust variance estimation was used to calculate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for the association between ambient UV exposure per interquartile range (IQR) increase (32.4 mW/m 2 ) and HCC risk adjusting for age at diagnosis, sex, race, year of diagnosis, SEER registry, and county-level information on prevalence of health conditions, lifestyle, socioeconomic, and environmental factors. Higher levels of ambient UV exposure were associated with statistically significant lower HCC risk (n = 56,245 cases; adjusted IRR per IQR increase: 0.83, 95% CI 0.77, 0.90; p ambient UV and HCC risk was observed among males (p for interaction = 0.01) and whites (p for interaction = 0.01). Higher ambient UV exposure was associated with a decreased risk of HCC in the U.S. UV exposure may be a potential modifiable risk factor for HCC that should be explored in future research.

High-accuracy X-ray detector calibration based on cryogenic radiometry

Science.gov (United States)

Krumrey, M.; Cibik, L.; Müller, P.

2010-06-01

Cryogenic electrical substitution radiometers (ESRs) are absolute thermal detectors, based on the equivalence of electrical power and radiant power. Their core piece is a cavity absorber, which is typically made of copper to achieve a short response time. At higher photon energies, the use of copper prevents the operation of ESRs due to increasing transmittance. A new absorber design for hard X-rays has been developed at the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the electron storage ring BESSY II. The Monte Carlo simulation code Geant4 was applied to optimize its absorptance for photon energies of up to 60 keV. The measurement of the radiant power of monochromatized synchrotron radiation was achieved with relative standard uncertainties of less than 0.2 %, covering the entire photon energy range of three beamlines from 50 eV to 60 keV. Monochromatized synchrotron radiation of high spectral purity is used to calibrate silicon photodiodes against the ESR for photon energies up to 60 keV with relative standard uncertainties below 0.3 %. For some silicon photodiodes, the photocurrent is not linear with the incident radiant power.

High-accuracy X-ray detector calibration based on cryogenic radiometry

International Nuclear Information System (INIS)

Krumrey, M.; Cibik, L.; Mueller, P.

2010-01-01

Cryogenic electrical substitution radiometers (ESRs) are absolute thermal detectors, based on the equivalence of electrical power and radiant power. Their core piece is a cavity absorber, which is typically made of copper to achieve a short response time. At higher photon energies, the use of copper prevents the operation of ESRs due to increasing transmittance. A new absorber design for hard X-rays has been developed at the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the electron storage ring BESSY II. The Monte Carlo simulation code Geant4 was applied to optimize its absorptance for photon energies of up to 60 keV. The measurement of the radiant power of monochromatized synchrotron radiation was achieved with relative standard uncertainties of less than 0.2 %, covering the entire photon energy range of three beamlines from 50 eV to 60 keV. Monochromatized synchrotron radiation of high spectral purity is used to calibrate silicon photodiodes against the ESR for photon energies up to 60 keV with relative standard uncertainties below 0.3 %. For some silicon photodiodes, the photocurrent is not linear with the incident radiant power.

Contribution of Topography and Incident Solar Radiation to Variation of Soil and Plant Litter at an Area with Heterogeneous Terrain

Directory of Open Access Journals (Sweden)

Felipe Cito Nettesheim

2015-06-01

Full Text Available Natural processes that determine soil and plant litter properties are controlled by multiple factors. However, little attention has been given to distinguishing the effects of environmental factors from the effects of spatial structure of the area on the distribution of soil and litter properties in tropical ecosystems covering heterogeneous topographies. The aim of this study was to assess patterns of soil and litter variation in a tropical area that intercepts different levels of solar radiation throughout the year since its topography has slopes predominantly facing opposing geographic directions. Soil data (pH, C, N, P, H+Al, Ca, Mg, K, Al, Na, sand, and silt and plant litter data (N, K, Ca, P, and Mg were gathered together with the geographic coordinates (to model the spatial structure of 40 sampling units established at two sites composed of slopes predominantly facing northwest and southeast (20 units each. Soil and litter chemical properties varied more among slopes within similar geographic orientations than between the slopes facing opposing directions. Both the incident solar radiation and the spatial structure of the area were relevant in explaining the patterns detected in variation of soil and plant litter. Individual contributions of incident solar radiation to explain the variation in the properties evaluated suggested that this and other environmental factors may play a particularly relevant role in determining soil and plant litter distribution in tropical areas with heterogeneous topography. Furthermore, this study corroborates that the spatial structure of the area also plays an important role in the distribution of soil and litter within this type of landscape, which appears to be consistent with the action of water movement mechanisms in such areas.

Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

Energy Technology Data Exchange (ETDEWEB)

Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

2014-09-08

A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

Analysis of a radiological incident and lessons to be learned: a case of industrial radiographic incident in great Britain

International Nuclear Information System (INIS)

Croft, J.; Lefaure, Ch.

2000-01-01

This note describes a case study to provide feedback analysis and lessons to be learned from a radiological incident. This one occurred in the UK. It has been published in the European ALARA Newsletter no. 2 (January 1997) and has been selected from the IRID database (Ionising Radiation Incident Database) managed by the Health and Safety Executive, National Radiological Protection Board and Environmental Agency. (authors)

Statistical analysis of monochromatic whistler waves near the Moon detected by Kaguya

Directory of Open Access Journals (Sweden)

Y. Tsugawa

2011-05-01

Full Text Available Observations are presented of monochromatic whistler waves near the Moon detected by the Lunar Magnetometer (LMAG on board Kaguya. The waves were observed as narrowband magnetic fluctuations with frequencies close to 1 Hz, and were mostly left-hand polarized in the spacecraft frame. We performed a statistical analysis of the waves to identify the distributions of their intensity and occurrence. The results indicate that the waves were generated by the solar wind interaction with lunar crustal magnetic anomalies. The conditions for observation of the waves strongly depend on the solar zenith angle (SZA, and a high occurrence rate is recognized in the region of SZA between 40° to 90° with remarkable north-south and dawn-dusk asymmetries. We suggest that ion beams reflected by the lunar magnetic anomalies are a possible source of the waves.

Incidence of hypothyroidism after radioiodine treatment of hyperthyroidism

International Nuclear Information System (INIS)

Anno, Yasuro; Sasaki, Tsutomu; Takeshita, Akihisa; Nakamura, Yoshiyuki; Torizuka, Kanji.

1975-01-01

To investigate whether the incidence of hypothyroidism after 131 I treatment of patients with hyperthyroidism is lower in Japan than in the Western countries, the results of treatment were retrospectively analyzed with patients to whom 131 I had been administered, individually estimating radiation dose to the thyroid. A total of 1119 patients treated at five clinics from 1955 to 1967 were evaluated in 1969. The average initial dose of 131 I in the present series was 5.6 m Ci and 6340 rads to the thyroid, and this was an average dose used in Japan for the corresponding period. The results of treatment were analyzed by the one-dose group (625 cases) and the repeat-dose group (494 cases), as well as for total cases. The incidence of hypothyroidism was calculated by the life table method and, of the total cases, the incidence was 9.4, 18, and 26%, 5, 10, and 12 years respectively after the initial treatment. The rate of hypothyroidism was generally a little higher and the increment by the end of 5 years was steeper in the one-dose group than in the repeat-dose group. In reviewing the results between the Western countries and Japan, including the present series, fairly good correlation was found between radiation dose to the thyroid in the initial dose and the incidence of hypothyroidism 5 years after the initial dose. The lower incidence of hypothyroidism in Japan appeared due mainly to a lower radiation dose to the thyroid in the initial treatment. Radiation doses to the thyroid glands of patients who became hypothyroid in the one-dose group were 7220 +- 2810 rads and ranged from less than 3000 rads to more than 14000 rads. Of the patients in the one-dose group, whose thyroid received a definite dose ranging from 6000 to 8000 rads, those with less thyroid enlargement were more apt to develop hypothyroidism. (auth.)

Preventing radiation retinopathy with hyperfractionation

International Nuclear Information System (INIS)

Monroe, Alan T.; Bhandare, Niranjan; Morris, Christopher G.; Mendenhall, William M.

2005-01-01

Purpose: The purpose of this study was to determine factors associated with the development of radiation retinopathy in a large series of patients with head-and-neck cancer. In particular, we addressed whether the use of hyperfractionated radiation therapy was effective in reducing the risk of retinopathy. Methods and materials: One hundred eighty-six patients received a significant dose to the retina as part of curative radiotherapy. Primary sites included: nasopharynx, 46; paranasal sinus, 64; nasal cavity, 69; and palate, 7. Prescription doses varied depending on primary site and histology. Hyperfractionated (twice-daily) radiation was delivered to 42% of the patients in this study, typically at 1.10 to 1.20 Gy per fraction. The remainder were treated once-daily. Retinal doses were determined from computerized dosimetry plans when available. For all other patients, retinal doses were retrospectively calculated using reconstructed off-axis dosimetry taken from contours through the center of the globes. Retinal dose was defined as the minimum dose received by at least 25% of the globe. The median retinal dose was 56.85 Gy. Patients were followed for a median of 7.6 years. Results: Thirty-one eyes in 30 patients developed radiation retinopathy, resulting in monocular blindness in 25, bilateral blindness in 1, and decreased visual acuity in 4. The median time to the diagnosis of retinopathy was 2.6 years (range, 11 months to 5.3 years). The actuarial incidence of developing radiation retinopathy was 20% at both 5 and 10 years. The incidence of developing ipsilateral blindness due to retinopathy was 16% at 5 years and 17% at 10 years. Site-specific incidences varied considerably, with ethmoid sinus (9 of 25, 36%), nasal cavity (13 of 69, 19%), and maxillary sinus (6 of 35, 17%) being the most common sites associated with radiation retinopathy. Three of 72 patients (4%) receiving retinal doses less than 50 Gy developed retinopathy. Higher retinal doses resulted in a

Performance study of monochromatic synchrotron X-ray computed tomography using a linear array detector

Energy Technology Data Exchange (ETDEWEB)

Kazama, Masahiro; Takeda, Tohoru; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Akiba, Masahiro; Yuasa, Tetsuya; Hyodo, Kazuyuki; Ando, Masami; Akatsuka, Takao

1997-09-01

Monochromatic x-ray computed tomography (CT) using synchrotron radiation (SR) is being developed for detection of non-radioactive contrast materials at low concentration for application in clinical diagnosis. A new SR-CT system with improved contrast resolution, was constructed using a linear array detector which provides wide dynamic ranges and a double monochromator. The performance of this system was evaluated in a phantom and a rat model of brain ischemia. This system consists of a silicon (111) double crystal monochromator, an x-ray shutter, an ionization chamber, x-ray slits, a scanning table for the target organ, and an x-ray linear array detector. The research was carried out at the BLNE-5A bending magnet beam line of the Tristan Accumulation Ring in KEK, Japan. In this experiment, the reconstructed image of the spatial-resolution phantom clearly showed the 1 mm holes. At 1 mm slice thickness, the above K-edge image of the phantom showed contrast resolution at the concentration of 200 {mu}g/ml iodine-based contrast materials whereas the K-edge energy subtraction image showed contrast resolution at the concentration of 500 {mu}g/ml contrast materials. The cerebral arteries filled with iodine microspheres were clearly revealed, and the ischemic regions at the right temporal lobe and frontal lobe were depicted as non-vascular regions. The measured minimal detectable concentration of iodine on the above K-edge image is about 6 times higher than the expected value of 35.3 {mu}g/ml because of the high dark current of this detector. Thus, the use of a CCD detector which is cooled by liquid nitrogen to improve the dynamic range of the detector, is being under construction. (author)

Photomorphogenic effects of UV-B radiation on plants: consequences for light competition

International Nuclear Information System (INIS)

Barnes, P.W.; Ballaré, C.L.; Caldwell, M.M.

1996-01-01

A combination of field and labotatory studies were conducted to explore the nature of photomorphogenic effects of ultraviolet-B radiation (UV-B; 280–320 nm) on plant morphology and to evaluate the ecological consequences of these alterations in morphology for interspecific competition. Under laboratory conditions, seedlings of cucumber (Cucumis sativus L.) and tomato (Lycopersicon esculentum Mill.) exhibited appreciable (ca. 50%) and rapid (< 3h) inhibition in hypocotyl elongation in response to UV-B exposure. In cucumber, this inhibition was reversible, occurred without any associated changes in dry matter production and was caused by UV-B incident on the cotyledons and not the stem or growing tip. Inhibition of stem elongation in etiolated tomato seedlings occurred at least 3 h prior to the onset of accumulation of UV-absorbing pigments and monochromatic UV supplied against a background of visible radiation revealed maximum effectiveness in inhibition around 300 nm. Collectively, these findings suggest that a specific, but yet unidentified, UV-B photoreceptor is involved in mediating certain morphological responses to UV-B. For mixtures of wheat (Triticum aestivum L.) and wild oat (Avena fatua L.), a common weedy competitor, supplemental UV-B irradiation in the field differentially altered shoot morphology which resulted in changes in canopy structure, light interception and calculated stand photosynthesis. It is argued that, because of its asymmetrical nature, competition for light can potentially amplify the effects of UV-B on shoot morphology and may, therefore, be an important mechanism by which changes in the solar UV-B spectrum associated with stratospheric ozone reduction could alter the composition and character of terrestrial vegetation

Simulation of Solar Radiation Incident on Horizontal and Inclined Surfaces

Directory of Open Access Journals (Sweden)

MA Basunia

2012-12-01

Full Text Available A computer model was developed to simulate the hourly, daily and monthly average of daily solar radiation on horizontal and inclined surfaces. The measured hourly and daily solar radiation was compared with simulated radiation, and favourable agreement was observed for the measured and predicted values on clear days. The measured and simulated monthly averages of total (diffuse and beam daily solar radiation were compared and a reasonable agreement was observed for a number of stations in Japan. The simulation showed that during the rice harvesting season, September to October, there is a daily average of 14.7 MJ/m2 of solar irradiation on a horizontal surface in Matsuyama, Japan. There is a similar amount of solar radiation on a horizontal surface during the major rice harvesting season, November to December, in Bangladesh. This radiation can be effectively utilized for drying rough rice and other farm crops.

Room-temperature effects of UV radiation in KBr:Eu{sup 2+} crystals

Energy Technology Data Exchange (ETDEWEB)

Perez-Salas, R; Melendrez, R [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada - IFUNAM, Ensenada, Apartado Postal 2732 Ensenada, BC, 22800 (Mexico); Aceves, R; Rodriguez, R; Barboza-Flores, M [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088 Hermosillo, Sonora, 83190 (Mexico)

1996-07-01

Thermoluminescence and optical absorption measurements have been carried out in KBr:Eu{sup 2+} crystals irradiated with monochromatic UV light (200-300 nm) and x-rays at room temperature. For UV- and x-irradiated crystals strong similarities between the thermoluminescence glow curves have been found, suggesting that the low-energy UV radiation produces the same defects as produced by x-irradiation in this material. The thermoluminescence glow curves are composed of six glow peaks located at 337, 383, 403, 435, 475 and 509 K. Thermal annealing experiments in previously irradiated crystals show clearly a correlation between the glow peak located at 383 K and the F-centre thermal bleaching process. Also, the excitation spectrum for each thermoluminescence glow peak has been investigated, showing that the low-energy radiation induces the formation of F centres. (author)

Gamma radiation influences postharvest disease incidence of pineapple fruits

International Nuclear Information System (INIS)

Damayanti, M.; Sharma, G.J.; Kundu, S.C.

1992-01-01

The application of gamma radiation for improving the storage of pineapple fruits [Ananas comosus (L.) Merr. cv. Queen] has been studied in an attempt to reduce decay caused by fungal pathogens such as Ceratocystis paradoxa (Dade)-Moreau and Penicillium purpurogenum Stoll. Gamma radiation at 50, 75, 100, 150, and 250 Gy improved shelf life. The maximum tolerable dose was approximately 250 Gy. Fruits irradiated with up to 150 Gy and then stored at 25 to 28C maintained their texture better than did the controls. Radiation, particularly at doses 250 Gy, caused browning of the skin and softening of tissues. Browning increased with increasing radiation dose and storage duration. Excessively high doses promoted spoilage. Doses in the range of 50 to 250 Gy, in combination with storage at 11 to 13C, can be used to reduce postharvest losses in pineapple due to fungal diseases and senescence, thereby extending shelf life

Cell response to quasi-monochromatic light with different coherence

Energy Technology Data Exchange (ETDEWEB)

Budagovsky, A V; Solovykh, N V [I.V.Michurin All-Russian Recearch Institute of Fruit Crops Genetics and Breeding (Russian Federation); Budagovskaya, O N [I.V.Michurin All-Russia Research and Development Institute of Gardening, Michurinsk, Tambov region (Russian Federation); Budagovsky, I A [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2015-04-30

The problem of the light coherence effect on the magnitude of the photoinduced cell response is discussed. The origins of ambiguous interpretation of the known experimental results are considered. Using the biological models, essentially differing in anatomy, morphology and biological functions (acrospires of radish, blackberry microsprouts cultivated in vitro, plum pollen), the effect of statistical properties of quasi-monochromatic light (λ{sub max} = 633 nm) on the magnitude of the photoinduced cell response is shown. It is found that for relatively low spatial coherence, the cell functional activity changes insignificantly. The maximal enhancement of growing processes (stimulating effect) is observed when the coherence length L{sub coh} and the correlation radius r{sub cor} are greater than the cell size, i.e., the entire cell fits into the field coherence volume. In this case, the representative indicators (germination of seeds and pollen, the spears length) exceeds those of non-irradiated objects by 1.7 – 3.9 times. For more correct assessment of the effect of light statistical properties on photocontrol processes, it is proposed to replace the qualitative description (coherent – incoherent) with the quantitative one, using the determination of spatial and temporal correlation functions and comparing them with the characteristic dimensions of the biological structures, e.g., the cell size. (biophotonics)

Training of an incidence of radiation on surfaces by vectorial representation; Didactica del analisis de la incidencia de radiacion solar mediante una representacion vectorial

Energy Technology Data Exchange (ETDEWEB)

Luis, F. J. de; Perez-Garcia, M.; Barbero, F. J.; Batlles, F. J.

2004-07-01

This work gathers and it exposes a set of educational contents extracted from the general bibliography and from the own experience in Engineering studies and courses on the application of a vector representation to the description of the apparent movement of the sun, the shading evaluation and the incidence of radiation on surfaces. (Author)

Base substitution spectra of nalidixylate resistant mutations induced by monochromatic soft X and 60Co γ-rays in bacillus subtilis spores

International Nuclear Information System (INIS)

Takahashi, Nobuhiro; Hieda, Kotaro; Morohoshi, Fumiko; Munakata, Nobuo

1999-01-01

Bacillus subtilis spores were exposed to three types of photons, monochromatic soft X-rays with the energy corresponding to the absorption peak of phosphorus K-shell electron (2,153 eV) and with the slightly lower energy (2,147 eV), and 60 Co γ-rays. From the irradiated spores, 233 mutants exhibiting nalidixic acid resistance were isolated, and together with 94 spontaneous mutants, the sequence changes in the 5'-terminal region of the gyrA gene coding for DNA gyrase subunit A were determined. Among eighteen alleles of the gyrA mutations, eight were single-base substitutions, nine were tandem double-base substitutions, and one was a double substitution skipping a middle base pair. About 6% of the radiation-induced mutations were tandem double-base substitutions, whereas none was observed among the spontaneous ones. Among spontaneous mutations, A:T and G:C pairs were equally subjected to mutations, whereas the substitutions from G:C pairs and those to A:T pairs predominated among those induced with soft X-rays. The peak-energy X-rays were more effective in killing and causing mutations than the low-energy X-rays, however, there seemed no base-change events uniquely attributable to phosphorus K-shell absorption. (author)

Radiation characteristics of helical tomotherapy

International Nuclear Information System (INIS)

Jeraj, Robert; Mackie, Thomas R.; Balog, John; Olivera, Gustavo; Pearson, Dave; Kapatoes, Jeff; Ruchala, Ken; Reckwerdt, Paul

2004-01-01

Helical tomotherapy is a dedicated intensity modulated radiation therapy (IMRT) system with on-board imaging capability (MVCT) and therefore differs from conventional treatment units. Different design goals resulted in some distinctive radiation field characteristics. The most significant differences in the design are the lack of flattening filter, increased shielding of the collimators, treatment and imaging operation modes and narrow fan beam delivery. Radiation characteristics of the helical tomotherapy system, sensitivity studies of various incident electron beam parameters and radiation safety analyses are presented here. It was determined that the photon beam energy spectrum of helical tomotherapy is similar to that of more conventional radiation treatment units. The two operational modes of the system result in different nominal energies of the incident electron beam with approximately 6 MeV and 3.5 MeV in the treatment and imaging modes, respectively. The off-axis mean energy dependence is much lower than in conventional radiotherapy units with less than 5% variation across the field, which is the consequence of the absent flattening filter. For the same reason the transverse profile exhibits the characteristic conical shape resulting in a 2-fold increase of the beam intensity in the center. The radiation leakage outside the field was found to be negligible at less than 0.05% because of the increased shielding of the collimators. At this level the in-field scattering is a dominant source of the radiation outside the field and thus a narrow field treatment does not result in the increased leakage. The sensitivity studies showed increased sensitivity on the incident electron position because of the narrow fan beam delivery and high sensitivity on the incident electron energy, as common to other treatment systems. All in all, it was determined that helical tomotherapy is a system with some unique radiation characteristics, which have been to a large extent

Computational study of nonlinear plasma waves. I. Simulation model and monochromatic wave propagtion

International Nuclear Information System (INIS)

Matda, Y.; Crawford, F.W.

1974-12-01

An economical low noise plasma simulation model is applied to a series of problems associated with electrostatic wave propagation in a one-dimensional, collisionless, Maxwellian plasma, in the absence of magnetic field. The model is described and tested, first in the absence of an applied signal, and then with a small amplitude perturbation, to establish the low noise features and to verify the theoretical linear dispersion relation at wave energy levels as low as 0.000,001 of the plasma thermal energy. The method is then used to study propagation of an essentially monochromatic plane wave. Results on amplitude oscillation and nonlinear frequency shift are compared with available theories. The additional phenomena of sideband instability and satellite growth, stimulated by large amplitude wave propagation and the resulting particle trapping, are described. (auth)

Atmospheric radiative transfer modeling: a summary of the AER codes

Energy Technology Data Exchange (ETDEWEB)

Clough, S.A. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States); Shephard, M.W. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States)]. E-mail: mshephar@aer.com; Mlawer, E.J. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States); Delamere, J.S. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States); Iacono, M.J. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States); Cady-Pereira, K. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States); Boukabara, S. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States); Brown, P.D. [Atmospheric and Environmental Research (AER) Inc., 131 Hartwell Avenue, Lexington, MA 02421-3126 (United States)

2005-03-01

The radiative transfer models developed at AER are being used extensively for a wide range of applications in the atmospheric sciences. This communication is intended to provide a coherent summary of the various radiative transfer models and associated databases publicly available from AER (http://www.rtweb.aer.com). Among the communities using the models are the remote sensing community (e.g. TES, IASI), the numerical weather prediction community (e.g. ECMWF, NCEP GFS, WRF, MM5), and the climate community (e.g. ECHAM5). Included in this communication is a description of the central features and recent updates for the following models: the line-by-line radiative transfer model (LBLRTM); the line file creation program (LNFL); the longwave and shortwave rapid radiative transfer models, RRTM{sub L}W and RRTM{sub S}W; the Monochromatic Radiative Transfer Model (MonoRTM); the MT{sub C}KD Continuum; and the Kurucz Solar Source Function. LBLRTM and the associated line parameter database (e.g. HITRAN 2000 with 2001 updates) play a central role in the suite of models. The physics adopted for LBLRTM has been extensively analyzed in the context of closure experiments involving the evaluation of the model inputs (e.g. atmospheric state), spectral radiative measurements and the spectral model output. The rapid radiative transfer models are then developed and evaluated using the validated LBLRTM model.

Incidence of thyroid carcinoma in patients with Hashimoto's thyroiditis and solitary cold nodules

Energy Technology Data Exchange (ETDEWEB)

Ott, R.A.; Calandra, D.B.; McCall, A.; Shah, K.H.; Lawrence, A.M.; Paloyan, E.

1985-12-01

The reported incidence of thyroid carcinoma in Hashimoto's thyroiditis varies widely. For this reason the specific subpopulation of patients with Hashimoto's thyroiditis and a solitary cold nodule was analyzed. Between 1972 and 1984 we operated on 146 consecutive patients with solitary cold nodules and Hashimoto's thyroiditis. There were 47 carcinomas, for an incidence of 32%. The mean age of the 146 patients was 43 1/2 years (median 44 years), with 126 females and 20 males. There was a history of prior head and neck radiation exposure in 54 patients, with a 33% incidence of thyroid carcinoma. The 92 patients without a history of radiation exposure had a 31.5% incidence of carcinoma. The frequency of multicentricity (bilateralism) was 33% in the group that underwent radiation and 24% in the group that did not. To date, with a mean follow-up of 4.7 years, there have been no deaths and no evidence of recurrence. In conclusion, we report a 32% incidence of thyroid carcinoma in patients with Hashimoto's thyroiditis and a solitary cold nodule, with no apparent difference between the patients with or without a history of radiation exposure, although there was a higher incidence of bilateralism (33% versus 24%) in the carcinomas of the patients with a history of head and neck irradiation. We suggest that the operative management of these patients is total thyroidectomy for those with a history of head and neck radiation and thyroid lobectomy for patients with no history of radiation, followed by contralateral lobectomy if a carcinoma is demonstrated.

Effect of front and rear incident proton irradiation on silicon solar cells

Science.gov (United States)

Anspaugh, Bruce; Kachare, Ram

1987-01-01

Four solar cell types of current manufacture were irradiated through the front and rear surfaces with protons in the energy range between 1 and 10 MeV. The solar cell parameters varied for this study were cell thickness and back surface field (BSF) vs. no BSF. Some cells were irradiated at normal incidence and an equal number were irradiated with simulated isotropic fluences. The solar cell electrical characteristics were measured under simulated AM0 illumination after each fluence. Using the normal incidence data, proton damage coefficients were computed for all four types of cells for both normal and omnidirectional radiation fields. These were found to compare well with the omnidirectional damage coefficients derived directly from the rear-incidence radiation data. Similarly, the rear-incidence omnidirectional radiation data were used to compute appropriate damage coefficients. A method for calculating the effect of a spectrum of energies is derived from these calculations. It is suitable for calculating the degradation of cells in space when they have minimal rear-surface shielding.

Asymmetric-cut variable-incident-angle monochromator.

Science.gov (United States)

Smither, R K; Graber, T J; Fernandez, P B; Mills, D M

2012-03-01

A novel asymmetric-cut variable-incident-angle monochromator was constructed and tested in 1997 at the Advanced Photon Source of Argonne National Laboratory. The monochromator was originally designed as a high heat load monochromator capable of handling 5-10 kW beams from a wiggler source. This was accomplished by spreading the x-ray beam out on the surface an asymmetric-cut crystal and by using liquid metal cooling of the first crystal. The monochromator turned out to be a highly versatile monochromator that could perform many different types of experiments. The monochromator consisted of two 18° asymmetrically cut Si crystals that could be rotated about 3 independent axes. The first stage (Φ) rotates the crystal around an axis perpendicular to the diffraction plane. This rotation changes the angle of the incident beam with the surface of the crystal without changing the Bragg angle. The second rotation (Ψ) is perpendicular to the first and is used to control the shape of the beam footprint on the crystal. The third rotation (Θ) controls the Bragg angle. Besides the high heat load application, the use of asymmetrically cut crystals allows one to increase or decrease the acceptance angle for crystal diffraction of a monochromatic x-ray beam and allows one to increase or decrease the wavelength bandwidth of the diffraction of a continuum source like a bending-magnet beam or a normal x-ray-tube source. When the monochromator is used in the doubly expanding mode, it is possible to expand the vertical size of the double-diffracted beam by a factor of 10-15. When this was combined with a bending magnet source, it was possible to generate an 8 keV area beam, 16 mm wide by 26 mm high with a uniform intensity and parallel to 1.2 arc sec that could be applied in imaging experiments.

Incidence Probability of Delayed Health Consequences of the Chernobyl Accident

International Nuclear Information System (INIS)

Abdel-Ghani, A.H.; El-Naggar, A.M.; El-Kadi, A.A.

2000-01-01

During the first international Conference on the long -term consequences of the Chernobyl disaster in 1995 at Kiev, and also during the 1996 International Conference at Vienna, Summing up the consequences of the Chernobyl accident, the data regarding the delayed health consequences were mainly related to thyroid cancer, hereditary disorders, general morbidity, mortality and psychological disturbances. Contrary to expectations, the incidences of Leukemia and Soft Tissue tumors were similar to the spontaneous incident. The expected delayed effects, however, among the accident survivors, the liquidators and populations resident in contaminated areas would show higher incidence probability to Leukemia. These population groups have been continuously exposed to low level radiation both externally and internally. Application of the new ICRP concept of radiation-induced Detriment, and the Nominal Probability Coefficient for Cancer and hereditary effects for both workers and populations are used as the rationale to calculate the incidence probability of occurrence of delayed health effects of the Chernobyl accidents

Ultraviolet Radiation Exposure and the Incidence of Oral, Pharyngeal and Cervical Cancer and Melanoma: An Analysis of the SEER Data.

Science.gov (United States)

Adams, Spencer; Lin, Jie; Brown, Derek; Shriver, Craig D; Zhu, Kangmin

2016-01-01

Based on the hypothesis that ultraviolet radiation (UVR) exposure can cause DNA damage that may activate dormant viruses such as human papilloma virus, a recent ecological study, which estimated state-level UVR exposure, reported positive correlations between annual UVR exposure and the incidence of oral, pharyngeal, and cervical cancer in 16 U.S. states using the International Agency for Research on Cancer (IARC) data. The purpose of the current study was to further investigate whether the annual UVR level, estimated on a county level, is associated with incidence rates of such cancers using the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) 18 data. If UVR exposure is associated with incidence of these cancer types, we would expect to see a similar or stronger association with melanoma because UVR exposure is a well-demonstrated risk factor for this disease. Thus, we also included melanoma in the study. The study subjects were White and Black individuals with oral, pharyngeal, cervical cancer or melanoma diagnosed between 1973 and 2011 from the SEER 18 data. UVR was estimated at the county level and grouped into high-, medium- and low-exposure levels. Age-adjusted incidence rates of cancer were calculated and compared among the UVR exposure groups. The comparisons were also stratified by sex and race. There was an inverse association between UVR exposure and incidence of oral, pharyngeal, and cervical cancer. The inverse association was also observed for melanoma. When stratified by race and sex, the inverse associations remained except for melanoma among Blacks. In contrast to a previous study, our study found that there were inverse associations between UVR exposure and the incidence of oral, pharyngeal, and cervical cancer, as well as of melanoma. Our findings are in agreement with several other published studies reporting no positive correlation between UVR exposure and the incidence rates of oral, pharyngeal, and cervical

Incidences of types of cancer in irradiated parabiont rats

International Nuclear Information System (INIS)

Warren, S.; Chute, R.N.; Brown, C.E.; Gates, O.

1982-01-01

A total body dose of 1000 R X radiation to 1252 male and 1366 female NEDH rats protected by permanent parabiosis to an untreated partner yielded respective cancer incidences of 42.7 and 38.3% within mean life-spans slightly less than single controls. These incidences were significant at the 1% level of probability compared with lower rates in shielded partners as well as in over 600 control parabiont partners and 700 single controls in which both sexes were nearly equally represented. Significant cancer incidences were induced in skin and islet cells of males, soft supporting tissue, renal tubules, bone of males and females, and ovary. Parabiosis per se provided local conditions conducive to the development of sarcomas, possibly enhanced by radiation, in anastomosed tissue as well as systemic changes promoting the spontaneous development of lymphoma and leukemia in females and inhibiting that of mammary carcinoma in females and malignant pheochromocytoma in males. The effects in females were largely canceled by radiation. The function of dose and its modification by factors contingent to parabiosis are discussed in relation to reported data on rats of other strains exposed to sublethal or lethal total-body X-ray doses

Radiation-induced Pulmonary Damage in Lung Cancer Patients

International Nuclear Information System (INIS)

Chung, Su Mi; Choi, Ihl Bohng; Kang, Mi Mun; Kim, In Ah; Shinn, Kyung Sub

1993-01-01

Purpose: A retrospective analysis was performed to evaluate the incidence of radiation induced lung damage after the radiation therapy for the patients with carcinoma of the lung. Method and Materials: Sixty-six patients with lung cancer (squamous cell carcinoma 27, adenocarcinoma 14, large cell carcinoma 2, small cell carcinoma 13, unknown 10) were treated with definitive, postoperative or palliative radiation therapy with or without chemotherapy between July 1987 and December 1991. There were 50 males and 16 females with median age of 63 years(range: 33-80 years). Total lung doses ranged from 500 to 6,660 cGy (median 3960 cGy) given in 2 to 38 fractions (median 20) over a range of 2 to 150 days (median 40 days) using 6 MV or 15 MV linear accelerator. To represent different fractionation schedules of equivalent biological effect, the estimated single dose(ED) model, ED=D·N-0.377·T-0.058 was used in which D was the lung dose in cGy, N was the number of fractions, and T was the overall treatment time in days. The range of ED was 370 to 1357. The endpoint was a visible increase in lung density within the irradiated volume on chest X-ray as observed independently by three diagnostic radiologists. Patients were grouped according to ED, treatment duration, treatment modality and age, and the percent incidence of pulmonary damage for each group was determined. Result: In 40 of 66 patients, radiation induced change was seen on chest radiographs between 11 days and 314 days after initiation of radiation therapy. The incidence of radiation pneumonitis was increased according to increased ED, which was statistically significant (p=0.001). Roentgenographic charges consistent with radiation pneumonitis were seen in 100% of patients receiving radiotherapy after lobectomy or pneumonectomy, which was not statistically significant. In 32 patients who also received chemotherapy, there was no difference in the incidence of radiation induced charge between the group with radiation

The measurement and analysis of normal incidence solar UVB radiation and its application to the photoclimatherapy protocol for psoriasis at the Dead Sea, Israel.

Science.gov (United States)

Kudish, Avraham I; Harari, Marco; Evseev, Efim G

2011-01-01

The broad-band normal incidence UVB beam radiation has been measured at Neve Zohar, Dead Sea basin, using a prototype tracking instrument composed of a Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The diffuse and beam fraction of the solar global UVB radiation have been determined using the concurrently measured solar global UVB radiation. The diffuse fraction was observed to exceed 80% throughout the year. The application of the results of these measurements to the possible revision of the photoclimatherapy protocol for psoriasis patients at the Dead Sea medical spas is now under investigation. The suggested revision would enable the sun-exposure treatment protocol to take advantage of the very high diffuse fraction by allowing the patient to receive the daily dose of UVB radiation without direct exposure to the sun, viz. receive the diffuse UVB radiation under a sunshade. This would require an increase in sun-exposure time intervals, as the UVB radiation intensity beneath a sunshade is less than that on an exposed surface. © 2010 The Authors. Photochemistry and Photobiology © 2010 The American Society of Photobiology.

A Photodegradation Study of Three Common Paint and Plaster Biocides under monochromatic UV Light

DEFF Research Database (Denmark)

Minelgaite, Greta; Vollertsen, Jes; Nielsen, Asbjørn Haaning

2014-01-01

Photodegradation of the three common paint-and-plaster biocides (carbendazim, diuron and terbutryn) was investigated at controlled laboratory conditions. Samples prepared in two types of water (demineralized water and pond water) were subjected to 254 nm monochromatic UV light. Light intensity (W m......-2) in the experimental chamber was measured by a fiber optic spectrometer. The observed decline in biocide concentration was related with the light energy, accumulated during the time of degradation (kJ m-2), and 1st order photodegradation rate constants (m2 kJ-1) were determined. The obtained...... at selected laboratory conditions, as well as emphasize the importance of water type when investigating pollutant’s photo fate, as certain constituents might act as reaction enhancers or inhibitors....

The incidence of other primary cancers in patients with an oral cancer treated with radiation therapy

International Nuclear Information System (INIS)

Shimizutani, Kiminari; Koseki, Yonoshin; Ikeda, Hiroshi

1992-01-01

From January 1980 through April 1990, a total of 317 patients with an oral cancer were treated with radiation therapy at Department of Radiology, Osaka University Hospital. Twenty-seven (8.5%) of these 317 patients had other primary cancers. For statistical purposes, the expected number of other primary cancers was estimated by multiplying the age-sex specific incidence rates among Osaka residents with the Person-year at risk figures, based on the Osaka Prefectural Cancer Registry. The observed/expected [0/E] ratios were 16.00 (p<0.01) for the esophagus and 28.42 (p<0.01) for the oropharynx. The present study suggested the necessity of following up oral cancer patients, especially those who have had carcinoma of the mouth floor, in order to enable the early diagnosis of upper digestive tract cancer. (author)

The capabilities of monochromatic EC neutrino beams with the SPS upgrade

International Nuclear Information System (INIS)

Espinoza, C; Bernabeu, J

2008-01-01

The goal for future neutrino facilities is the determination of the U(e3) mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source and energy control. With this objective in mind, the creation of monochromatic neutrino beams from the electron capture decay of boosted ions by the SPS of CERN has been proposed. We discuss the capabilities of such a facility as a function of the energy of the boost and the baseline for the detector. We conclude that the SPS upgrade to 1000 GeV is crucial to reach a better sensitivity to CP violation iff it is accompanied by a longer baseline. We compare the physics potential for two different configurations: I) γ = 90 and γ = 195 (maximum achievable at present SPS) to Frejus; II) γ = 195 and γ = 440 (maximum achievable at upgraded SPS) to Canfranc. The main conclusion is that, whereas the gain in the determination of U(e3) is rather modest, setup II provides much better sensitivity to CP violation

The capabilities of monochromatic EC neutrino beams with the SPS upgrade

Science.gov (United States)

Espinoza, C.; Bernabéu, J.

2008-05-01

The goal for future neutrino facilities is the determination of the U(e3) mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source and energy control. With this objective in mind, the creation of monochromatic neutrino beams from the electron capture decay of boosted ions by the SPS of CERN has been proposed. We discuss the capabilities of such a facility as a function of the energy of the boost and the baseline for the detector. We conclude that the SPS upgrade to 1000 GeV is crucial to reach a better sensitivity to CP violation iff it is accompanied by a longer baseline. We compare the physics potential for two different configurations: I) γ = 90 and γ = 195 (maximum achievable at present SPS) to Frejus; II) γ = 195 and γ = 440 (maximum achievable at upgraded SPS) to Canfranc. The main conclusion is that, whereas the gain in the determination of U(e3) is rather modest, setup II provides much better sensitivity to CP violation.

Micron-CT using quasi-monochromatic x-rays produced in micro-PIXE

International Nuclear Information System (INIS)

Ishii, K.

2009-01-01

In ion-atom collision, characteristic X-rays are intensively produced and can be considered as a monochromatic X-ray source. We apply this feature to X-ray CT. By using micro-beams, cross sectional images can be provided with a spatial resolution of about 1 μm. On the basis of this idea, we developed a micron-CT consisting of a micro-beam system and an X-ray CCD camera. A tube holding samples was rotated by a stepping motor and the transmission images of the sample were taken with characteristic K-X-rays of Ti (4.558 keV) produced by 3 MeV proton micro-beams. After image reconstruction, images of cross sections of small objects were obtained with a spatial resolution of 3 μm. Using an absorption edge, we can identify an element in a sample. It is expected that our micron-CT can provide cross sectional images of in-vivo cellular samples and can be applied to a wide range of researches in biology and medicine. (author)

Theoretical comparison of light scattering and guided wave coupling in multilayer coated optical components with random interface roughness

International Nuclear Information System (INIS)

Elson, J.M.

1995-01-01

In this work, we use first-order perturbation theory to calculate and then compare the (1) angular distribution of incident light scattered from a multilayer-coated optical component and (2) the angular distribution of incident light coupled into guided waves supported by the multilayer component. The incident beam is assumed to be a monochromatic plane wave and the scattering/coupling is assumed to be caused by roughness at the interfaces of the optical component. Numerical results show that for high quality (low root mean square roughness) optical components, comparison of the relative amounts of incident energy (1) scattered out of the specular beam and (2) coupled into guided waves are comparable. It follows that the guided wave energy will further contribute to the scattered field via radiative decay or be converted to heat. Thus, this work can help provide an estimation of when guided wave coupling can occur along with the expected magnitude. (orig.)

Computational study of nonlinear plasma waves. I. Simulation model and monochromatic wave propagation

International Nuclear Information System (INIS)

Matsuda, Y.; Crawford, F.W.

1975-01-01

An economical low-noise plasma simulation model originated by Denavit is applied to a series of problems associated with electrostatic wave propagation in a one-dimensional, collisionless, Maxwellian plasma, in the absence of magnetic field. The model is described and tested, first in the absence of an applied signal, and then with a small amplitude perturbation. These tests serve to establish the low-noise features of the model, and to verify the theoretical linear dispersion relation at wave energy levels as low as 10 -6 of the plasma thermal energy: Better quantitative results are obtained, for comparable computing time, than can be obtained by conventional particle simulation models, or direct solution of the Vlasov equation. The method is then used to study propagation of an essentially monochromatic plane wave. Results on amplitude oscillation and nonlinear frequency shift are compared with available theories

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

International Nuclear Information System (INIS)

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

2001-01-01

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

Radiation imaging

Energy Technology Data Exchange (ETDEWEB)

Redmayne, I.

1986-05-21

A detector for the detection of radiation such as X-ray radiation comprises an array of scintillation elements embedded in a sheet of radiation absorbing material. The scintillation elements are monitored individually, for example by a corresponding array of photodiodes, to build up a picture of the incident radiation. The front face of the sheet and the inner walls of the bores may be coated with a reflective material. The detector finds particular application in weld radiography. The detector may be stepped relative to the radiation source, the signals produced by the rows of the detector as they pass a predetermined point being summed.

Radiation imaging

International Nuclear Information System (INIS)

Redmayne, Ian.

1986-01-01

A detector for the detection of radiation such as X-ray radiation comprises an array of scintillation elements embedded in a sheet of radiation absorbing material. The scintillation elements are monitored individually, for example by a corresponding array of photodiodes, to build up a picture of the incident radiation. The front face of the sheet and the inner walls of the bores may be coated with a reflective material. The detector finds particular application in weld radiography. The detector may be stepped relative to the radiation source, the signals produced by the rows of the detector as they pass a predetermined point being summed. (author)

Ionizing radiations

International Nuclear Information System (INIS)

Newton, W.

1984-01-01

The purpose of this article is to simplify some of the relevant points of legislation, biological effects and protection for the benefit of the occupational health nurse not familiar with the nuclear industries. The subject is dealt with under the following headings; Understanding atoms. What is meant by ionizing radiation. Types of ionizing radiation. Effects of radiation: long and short term somatic effects, genetic effects. Control of radiation: occupational exposure, women of reproductive age, medical aspects, principles of control. The occupational health nurse's role. Emergency arrangements: national arrangements for incidents involving radiation, action to be taken by the nurse. Decontamination procedures: external and internal contamination. (U.K.)

Mirror and grating surface figure requirements for grazing incidence synchrotron radiation beamlines: Power loading effects

Energy Technology Data Exchange (ETDEWEB)

Hulbert, S.L.; Sharma, S.

1987-01-01

At present, grazing incidence mirrors are used almost exclusively as the first optical element in VUV and soft x-ray synchrotron radiation beamlines. The performance of these mirrors is determined by thermal and mechanical stress-induced figure errors as well as by figure errors remaining from the grinding and polishing process. With the advent of VUV and soft x-ray undulators and wigglers has come a new set of thermal stress problems related to both the magnitude and the spatial distribution of power from these devices. In many cases the power load on the entrance slits and gratings in these beamlines is no longer negligible. The dependence of thermally-induced front-end mirror figure errors on various storage ring and insertion device parameters (especially those at the National Synchrotron Light Source) and the effects of these figure errors on two classes of soft x-ray beamlines are presented.

On the stochastic interaction of monochromatic Alfven waves with toroidally trapped particles

International Nuclear Information System (INIS)

Krlin, L.; Pavlo, P.; Tluchor, Z.; Gasek, Z.

1987-07-01

Monochromatic Alfven wave interaction with toroidaly trapped particles in the intrinsic stochasticity regime is discussed. Both the diffusion in velocities and in the radial position of bananas is studied. Using a suitable Hamiltonian formalism, the effect of wave parallel components E-tilde paral and B-tilde paral is investigated. The stochasticity threshold is estimated for plasma electrons and for thermonuclear alpha-particles (neglecting the effect of B-tilde paral ) by means of direct numerical integration of the corresponding canonical equations. Stochasticity causes transfer between trapped and untrapped regimes and the induced radial diffusion of bananas. The latter effect can considerably exceed neoclassical diffusion. The effect of B-tilde paral was only estimated analytically. It consisted in frequency modulation of the banana periodic motion coupled with a possible Mathieu instability. Nevertheless, for B-tilde paral corresponding to E-tilde paral , the effect seems to be weaker than the effect of E-tilde paral when the thermonuclear regime is considered. (author). 14 figs., 36 refs

Inactivation of the lactose permease of Escherichia coli by monochromatic ultraviolet light

Energy Technology Data Exchange (ETDEWEB)

Robb, F T; Peak, M J [Rhodes Univ., Grahamstown (South Africa)

1979-09-01

The lactose permease of E. coli was inactivated exponetially by seven wavelengths of monochromatic UV light. An action spectrum revealed that the shorter wavelengths (243, 290 and 313 nm) were much more efficient than longer wavelengths. Inactivation at 290 nm was most efficient and was not due to generalized membrane damage. The rate of counterflux of intracellular ..beta..-galactoside in response to externally added ..beta..-galactoside was slowed by 290 nm irradiation, indicating destruction of the facilitated diffusion mechanism. The induction of ..beta..-galactosidase and ..beta..-galactoside permease was co-ordinate both with and without pre-irradiation by 290 nm light. The ..beta.. galactosidase was approximately 26-fold more resistant to 290 nm than the permease. These results are discussed in terms of a greater sensitivity of membrane proteins to 290 nm light, which may be due to the role of aromatic amino acids in conferring stability to the permease in the membrane.

Radiation damage characterization in reactor pressure vessel steels with nonlinear ultrasound

International Nuclear Information System (INIS)

Matlack, K. H.; Kim, J.-Y.; Wall, J. J.; Qu, J.; Jacobs, L. J.

2014-01-01

Nuclear generation currently accounts for roughly 20% of the US baseload power generation. Yet, many US nuclear plants are entering their first period of life extension and older plants are currently undergoing assessment of technical basis to operate beyond 60 years. This means that critical components, such as the reactor pressure vessel (RPV), will be exposed to higher levels of radiation than they were originally intended to withstand. Radiation damage in reactor pressure vessel steels causes microstructural changes such as vacancy clusters, precipitates, dislocations, and interstitial loops that leave the material in an embrittled state. The development of a nondestructive evaluation technique to characterize the effect of radiation exposure on the properties of the RPV would allow estimation of the remaining integrity of the RPV with time. Recent research has shown that nonlinear ultrasound is sensitive to radiation damage. The physical effect monitored by nonlinear ultrasonic techniques is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave, arising from the interaction of the ultrasonic wave with microstructural features such as dislocations, precipitates, and their combinations. Current findings relating the measured acoustic nonlinearity parameter to increasing levels of neutron fluence for different representative RPV materials are presented

Radiation damage characterization in reactor pressure vessel steels with nonlinear ultrasound

Science.gov (United States)

Matlack, K. H.; Kim, J.-Y.; Wall, J. J.; Qu, J.; Jacobs, L. J.

2014-02-01

Nuclear generation currently accounts for roughly 20% of the US baseload power generation. Yet, many US nuclear plants are entering their first period of life extension and older plants are currently undergoing assessment of technical basis to operate beyond 60 years. This means that critical components, such as the reactor pressure vessel (RPV), will be exposed to higher levels of radiation than they were originally intended to withstand. Radiation damage in reactor pressure vessel steels causes microstructural changes such as vacancy clusters, precipitates, dislocations, and interstitial loops that leave the material in an embrittled state. The development of a nondestructive evaluation technique to characterize the effect of radiation exposure on the properties of the RPV would allow estimation of the remaining integrity of the RPV with time. Recent research has shown that nonlinear ultrasound is sensitive to radiation damage. The physical effect monitored by nonlinear ultrasonic techniques is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave, arising from the interaction of the ultrasonic wave with microstructural features such as dislocations, precipitates, and their combinations. Current findings relating the measured acoustic nonlinearity parameter to increasing levels of neutron fluence for different representative RPV materials are presented.

Biological implications of radiation

International Nuclear Information System (INIS)

Bond, V.P.

1977-01-01

Some topics discussed are as follows: effects of diagnostic and therapeutic radiation on dividing cells, DNA, and blood cells; radiation sickness in relation to dose; early and late effects of radiation; effects of low dose irradiation; dose-effect curves; radioinduction of tumors in animals; and incidence of cancer in children following in utero exposure to diagnostic x rays

Radiation practices. Annual report 2008

International Nuclear Information System (INIS)

Rantanen, E.

2009-09-01

1775 safety licences for the use of radiation were current at the end of 2008. 1831 responsible parties were engaged in notifiable licence-exempt dental X-ray activities. Use of radiation was controlled through regular inspections performed at places of use, test packages sent by post to dental X-ray facilities and maintenance of the Dose Register. Radiation safety guides were also published and research was conducted in support of regulatory control. STUK conducted 424 inspections of licensed practices and 18 inspections of notifiable licence-exempt dental X-ray practices in 2008. 209 repair orders and recommendations were issued. Use of one appliance was prohibited. A total of just over 11 500 workers were subject to individual monitoring in 2008, and about 140 000 dose entries were made in the Dose Register maintained by STUK. Regulatory control of natural radiation focused on radon at workplaces and exposure of aircrews to cosmic radiation. 89 workplaces including a total of 201 work areas were subject to radon monitoring during 2008. Some 3700 pilots and cabin crew members were monitored for exposure to cosmic radiation. Metrological activities continued with calibration and development work as in previous years. Regulatory control of the use of non-ionizing radiation in 2008 focused particularly on mobile phones, sunbeds and lasers. Ten mobile phone types and five baby monitors were tested in market surveillance of wireless communication devices. 25 sunbed facilities were inspected and nine laser display inspections were performed. There were 22 abnormal incidents involving the use of radiation in 2008. Seventeen of these incidents concerned the use of radiation in industry, research or transportation, four concerned the use of radiation in health care, and one concerned the use of non-ionizing radiation. None of these incidents had serious consequences. (orig.)

Safety-related incidents at the Finnish nuclear power plants

International Nuclear Information System (INIS)

Lehtinen, P.

1986-03-01

This report contains detailed descriptions of operating incidents and other safety-related matters at the Finnish nuclear power plants regarded as significant by the regulatory authority, the Finnish Centre for Radiation and Nuclear Safety. In this connection, an account is given of the practical actions caused by the incidents, and their significance to reactor safety is evaluated. The main features of the incidents are also described in the general Quartely Reports, Operation of Finnish Nuclear Power Plants, which are supplemented by this report intended for experts. (author)

Safety-related incidents at the Finnish nuclear power plants

International Nuclear Information System (INIS)

Lehtinen, P.

1985-01-01

This report contains detailed descriptions of operating incidents and other safety-related matters at the Finnish nuclear power plants regarded as significant by the regulatory authority, the Finnish Centre for Radiation and Nuclear Safety. In this connection, an account is given of the practical actions caused by the incidents, and their significance to reactor safety is evaluated. The main features of the incidents are also described in the general Quartely Reports, Operation of Finnish Nuclear Power Plants, which are supplemented by this report intended for experts. (author)

Radiation produced by electrons incident on molecules

International Nuclear Information System (INIS)

Moehlman, G.R.

1977-01-01

The work described in this thesis deals with light intensity measurements of emission spectra (1850-9000 A) produced by a continuous or pulsed beam of monoenergetic electrons (0 - 2000 eV) incident on a variety of molecular gases like H 2 , D 2 , H 2 O, HCl, NH 3 and several hydrocarbons. The emission spectra are dominated by fluorescence from excited fragments produced via dissociative excitation, besides fluorescence from excited parent molecules themselves. The experimental results thus obtained are expressed in terms of emission cross sections and lifetimes

Changes of plasma growth hormone, insulin-like growth factors-I, thyroid hormones, and testosterone concentrations in embryos and broiler chickens incubated under monochromatic green light

Directory of Open Access Journals (Sweden)

Lin Zhang

2014-07-01

Full Text Available Previous studies showed that monochromatic green light stimuli during embryogenesis accelerated posthatch body weight and pectoral muscle growth of broilers. In this experiment, we further investigated whether the regulation of broiler embryonic or posthatch growth by green light stimulus during incubation is associated with the changes of some important hormones at different ages of embryos and broiler chickens. Fertile broiler eggs (Arbor Acres, n=880 were pre-weighed and randomly assigned 1 of 2 incubation treatment groups: i dark condition (control group, and ii monochromatic green light group (560 nm. The monochromatic lighting systems sourced from light-emitting diode lamps were equalised at the intensity of 15 lux (lx at eggshell level. The dark condition was set as a commercial control from day one until hatching. After hatch, 120 day-old male chicks from each group were housed under white light with an intensity of 30 lx at bird-head level. Compared with the dark condition, chicks incubated under the green light showed significantly higher growth hormone (GH levels from 19 d of embryogenesis (E19 to 5 d of posthatch (H5, and higher plasma insulinlike growth factor (IGF-I levels from both E17 to E19 and H3 to H35. No significant differences were found in plasma thyroxine, triiodothyronine, and testosterone in embryos or hatched birds between the 2 groups. These results indicate that somatotropic axis hormones (GH and IGF-I may be the most important contributor to chicken growth promoted by green light stimuli during embryogenesis.

Dual Energy CT (DECT Monochromatic Imaging: Added Value of Adaptive Statistical Iterative Reconstructions (ASIR in Portal Venography.

Directory of Open Access Journals (Sweden)

Liqin Zhao

Full Text Available To investigate the effect of the adaptive statistical iterative reconstructions (ASIR on image quality in portal venography by dual energy CT (DECT imaging.DECT scans of 45 cirrhotic patients obtained in the portal venous phase were analyzed. Monochromatic images at 70keV were reconstructed with the following 4 ASIR percentages: 0%, 30%, 50%, and 70%. The image noise (IN (standard deviation, SD of portal vein (PV, the contrast-to-noise-ratio (CNR, and the subjective score for the sharpness of PV boundaries, and the diagnostic acceptability (DA were obtained. The IN, CNR, and the subjective scores were compared among the four ASIR groups.The IN (in HU of PV (10.05±3.14, 9.23±3.05, 8.44±2.95 and 7.83±2.90 decreased and CNR values of PV (8.04±3.32, 8.95±3.63, 9.80±4.12 and 10.74±4.73 increased with the increase in ASIR percentage (0%, 30%, 50%, and 70%, respectively, and were statistically different for the 4 ASIR groups (p<0.05. The subjective scores showed that the sharpness of portal vein boundaries (3.13±0.59, 2.82±0.44, 2.73±0.54 and 2.07±0.54 decreased with higher ASIR percentages (p<0.05. The subjective diagnostic acceptability was highest at 30% ASIR (p<0.05.30% ASIR addition in DECT portal venography could improve the 70 keV monochromatic image quality.

Use of risk projection models to estimate mortality and incidence from radiation-induced breast cancer in screening programs

International Nuclear Information System (INIS)

Ramos, M; Ferrer, S; Villaescusa, J I; Verdu, G; Salas, M D; Cuevas, M D

2005-01-01

The authors report on a method to calculate radiological risks, applicable to breast screening programs and other controlled medical exposures to ionizing radiation. In particular, it has been applied to make a risk assessment in the Valencian Breast Cancer Early Detection Program (VBCEDP) in Spain. This method is based on a parametric approach, through Markov processes, of hazard functions for radio-induced breast cancer incidence and mortality, with mean glandular breast dose, attained age and age-at-exposure as covariates. Excess relative risk functions of breast cancer mortality have been obtained from two different case-control studies exposed to ionizing radiation, with different follow-up time: the Canadian Fluoroscopy Cohort Study (1950-1987) and the Life Span Study (1950-1985 and 1950-1990), whereas relative risk functions for incidence have been obtained from the Life Span Study (1958-1993), the Massachusetts tuberculosis cohorts (1926-1985 and 1970-1985), the New York post-partum mastitis patients (1930-1981) and the Swedish benign breast disease cohort (1958-1987). Relative risks from these cohorts have been transported to the target population undergoing screening in the Valencian Community, a region in Spain with about four and a half million inhabitants. The SCREENRISK software has been developed to estimate radiological detriments in breast screening. Some hypotheses corresponding to different screening conditions have been considered in order to estimate the total risk associated with a woman who takes part in all screening rounds. In the case of the VBCEDP, the total radio-induced risk probability for fatal breast cancer is in a range between [5 x 10 -6 , 6 x 10 -4 ] versus the natural rate of dying from breast cancer in the Valencian Community which is 9.2 x 10 -3 . The results show that these indicators could be included in quality control tests and could be adequate for making comparisons between several screening programs

Assessment of risk from radiation sources

International Nuclear Information System (INIS)

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

1976-01-01

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

Radiation protection aspects of the incident recovery

International Nuclear Information System (INIS)

Tibor, Bujtas; Arpad, Nenyei

2006-01-01

On the 10. April 2003 a serious accident occurred at PAKS nuclear power plant. The cleaning of fuel assemblies unloaded from the reactor of unit 2 was commencing under water in the fuel-cleaning equipment in the maintenance shaft number 1. There was no chain reaction in the cleaning tank but the fission products, accumulated in the previous operational time still produced a significant heat. Due to the inadequate cooling of the cleaning tank the assemblies overheated within a few hours. After opening the lid of the tank the entering cold water caused thermal shock and significant damage to the fuel assemblies. cladding of the fuel elements opened up and the uranium dioxide pellets got also damaged. The removal of the damaged fuel assemblies and the released debris must be managed. There are technical difficulties and radiation protection problems to reduce the radiation exposure of the workers as well as the minimization of the radioactive materials released into the environment. The description of the situation and the different actions are detailed. (N.C.)

Response of TAPS to monochromatic photons with energies between 45 and 790 MeV

International Nuclear Information System (INIS)

Gabler, A.R.; Doering, W.; Fuchs, M.; Krusche, B.; Metag, V.; Novotny, R.; Roebig-Landau, M.; Stroeher, H.; Tries, V.; Molenaar, C.; Loehner, H.; Van Pol, J.H.G.; Raschke, A.; Sumbera, M.; Venema, L.B.; Wilschut, H.W.; Averbeck, R.; Niebur, W.; Schubert, A.; Simon, R.S.; Beck, R.; Peise, J.; Miller, G.J.; Owens, R.O.; Anton, G.

1994-01-01

The Two Arm Photon Spectrometer TAPS - comprising 384 plastic-BaF 2 scintillator telescopes - was tested with monochromatic photons in the energy range between 45 and 790 MeV. The energy resolution for a collimated photon beam hitting the central detector module was determined to σ/E=0.59%xE -1/2 γ +1.9% (E γ given in GeV). For the the fast scintillation component alone σ/E=0.79%xE -1/2 γ +1.8% has been measured. The position resolution of the point of impact amounts to Δx=2 cm (FWHM) at the highest energies which corresponds to 30% of the diameter of an individual module. Monte Carlo simulations using the code GEANT3 are in good agreement with the experimental results. ((orig.))

Monochromatic Spectral Computed Tomography with Low Iodine Concentration Contrast Medium in a Rabbit VX2 Liver Model:: Investigation of Image Quality and Detection Rate.

Science.gov (United States)

Zhou, Yue; Xu, Han; Hou, Ping; Dong, Jun Q; Wang, Ming Y; Gao, Jian B

2016-04-01

This study aimed to validate the feasibility of using virtual monochromatic spectral computed tomography (CT) with isotonic low iodine concentration contrast medium for VX2 hepatic tumors. Sixty New Zealand white rabbits with implanted VX2 hepatic tumors underwent two-phase contrast-enhanced spectral CT imaging on the 14th day after tumor implantation. They were randomly divided into groups A, B, and C, with 20 rabbits each (group A: 270 mg I/mL, monochromatic spectral images; group B: 370 mg I/mL, conventional 120 kVp images, 100% filtered back projection [FBP]; group C: 270 mg I/mL, conventional 120 kVp images, 100% FBP). Group A was further divided into two subgroups (subgroup A1: 100% FBP; subgroup A2: 50% FBP + 50% adaptive statistical iterative reconstruction). Objective evaluation (signal-to-noise ratio [SNR], contrast-to-noise ratio [CNR], and image noise), subjective rating score (image noise score, anatomical details score, overall image quality score, and lesion conspicuity score), CT dose index volume, and dose length product were compared between groups during two-phase contrast enhancement. The detection rates of the four groups were calculated as percentages. Image noise (SNR and CNR) among the four groups was statistically significant (P noise in group A2 was lower than in group A1, but higher than that in groups B and C (P noise score of group A2 was higher than that of the other three groups. In terms of the anatomic details score, the overall image quality score, and the lesion conspicuity score, the images of group A2 were superior to that of groups A1 and C. For hepatic tumor diameters more than or equal to 1.0 cm and less than 3.0 cm, group A achieved a higher detection rate than groups B and C. The CT dose index volume, dose length product, and effective dose in group A were significantly lower than that in groups B and C (P noise, increase detection rate for small tumors, and decrease radiation dose and iodine load in

High incidence of hydrocephalus following prenatal exposure to X-irradiation at early gestational stage in mice

International Nuclear Information System (INIS)

Aolad, H.; Inouye, Minoru; Hayasaka, Shizu; Darmanto, W.; Murata, Yoshiharu

1998-01-01

Hydrocephalus is one of the severe brain anomalies. Several causes of congenital hydrocephalus have been reported and, it is known that radiation is one of those. The current study was designed to obtain postnatally viable hydrocephalic offspring at a high incidence following X-radiation. This finding will be helpful to elucidate the mechanism of congenital hydrocephalus caused by X-radiation. Twenty pregnant Slc:ICR mice, 5 in each group, were exposed to X-irradiation at a dose of 1.0 Gy on gestational days 7 (G7), G8, G9 or G10. The incidence of hydrocephalus was high in the group exposed on G7. An additional 21 pregnant mice were then exposed to a dose of 1.2 Gy, 1.3 Gy, 1.4 Gy or 1.5 Gy X-radiation on G7. The highest incidence of hydrocephalic offspring was found following exposure to 1.4 Gy X-radiation. (author)

Naturally occurring and radiation-induced tumors in SPF mice, and genetic influence in radiation leukemogenesis

International Nuclear Information System (INIS)

Kasuga, T.

1979-01-01

The data obtained so far in this study point to a strong genetic influence not only on the types and incidence of naturally occurring and radiation-induced tumors but also on radiation leukemogenesis. (Auth.)

Updated estimates of the proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionising radiation

International Nuclear Information System (INIS)

Little, Mark P; Wakeford, Richard; Kendall, Gerald M

2009-01-01

The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to update the previous results. Using the newer dosimetry we calculate that the best estimate of the proportion of cases of childhood leukaemia in Great Britain predicted to be attributable to this source of exposure is 15-20%, although the uncertainty associated with certain stages in the calculation (e.g. the nature of the transfer of risk between populations and the pertinent dose received from naturally occurring alpha-particle-emitting radionuclides) is significant. The slightly lower attributable proportions compared with those previously derived by Wakeford et al (Leukaemia 2009 23 770-6) are largely due to the lower doses (and in particular lower high LET doses) for the first year of life.

Medical application of Synchrotron Radiation

International Nuclear Information System (INIS)

Hyodo, Kazuyuki; Nishimura, Katsuyuki.

1990-01-01

The number of patients suffering from ischemic heart disease is also increasing rapidly in Japan. The standard method for assessing coronary artery diseases is the coronary angiography. Excellent images are taken by this method, however, it is an invasive method in which a catheter into a peripheral artery. The patients would obtain great benefit if the coronary arteries could be distinguished by intravenous injection of the contrast material. The K-edge subtraction method, which uses the K-edge discontinuity in the attenuation coefficient of the contrast material, is considered to be the most suitable method for coronary angiography by peripheral venous injection. Synchrotron Radiation (SR) is so intense that it allows selection of monochromatic X-rays, and studies on K-edge subtraction using SR has been started at some facilities. Recent activities K-edge subtraction method at the Accumulation Ring are briefly described here. (author)

A simple method for controlling the line width of SASE X-ray FELs

International Nuclear Information System (INIS)

Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

2010-04-01

This paper describes a novel single-bunch self-seeding scheme for generating highly monochromatic X-rays from a baseline XFEL undulator. A self-seeded XFEL consists of two undulators with an X-ray monochromator located between them. Previous self-seeding schemes made use of a four-crystal fixed-exit monochromator in Bragg geometry. In such monochromator the X-ray pulse acquires a cm-long path delay, which must be compensated. For a single-bunch self-seeding scheme this requires a long electron beam bypass, implying modifications of the baseline undulator configuration. To avoid this problem, a double bunch self-seeding scheme based on a special photoinjector setup was recently proposed. At variance, here we propose a new time-domain method of monochromatization exploiting a single crystal in the transmission direction, thus avoiding the problem of extra-path delay for the X-ray pulse. The method can be realized using a temporal windowing technique, requiring a magnetic delay for the electron bunch only. When the incident X-ray beam satisfies the Bragg diffraction condition, multiple scattering takes place and the transmittance spectrum in the crystal exhibits an absorption resonance with a narrow linewidth. Then, the temporal waveform of the transmitted radiation pulse is characterized by a long monochromatic wake. The radiation power within this wake is much larger than the shot noise power. At the entrance of the second undulator, the monochromatic wake of the radiation pulse is combined with the delayed electron bunch, and amplified up to saturation level. The proposed setup is extremely simple and composed of as few as two simple elements. These are the crystal and the short magnetic chicane, which accomplishes three tasks by itself. It creates an offset for crystal installation, it removes the electron micro-bunching produced in the first undulator, and it acts as a delay line for temporal windowing. Using a single crystal installed within a short magnetic

Monochromatic neutrinos from massive fourth generation neutrino annihilation in the Sun and Earth

International Nuclear Information System (INIS)

Belotskij, K.M.; Khlopov, M.Yu.; Shibaev, K.I.

2001-01-01

Accumulation inside the Earth and Sun of heavy (with the mass of 50 GeV) primordial neutrinos and antineutrinos of the fourth generation and their successive annihilation is considered. The minimal estimations of annihilational fluxes of monochromatic e, μ, τ neutrinos (neutrinos and antineutrinos) with the energy of 50 GeV are 4.1·10 -6 cm -2 ·s -1 from the Earth core and 1.1·10 -7 cm -2 ·s -1 from the Sun core. That makes the analysis of underground neutrino observatory data the additional source of information on the existence of massive stable 4th generation neutrino. It is shown that due to the kinetic equilibrium between the influx of the neutrinos and their annihilation the existence of new U(1)-gauge interaction of the 4th generation neutrino does not virtually influence the estimations of annihilational e-, μ-, τ-neutrino fluxes

Investigation of an incident due to orphan sources in Iran

Energy Technology Data Exchange (ETDEWEB)

Mehdizadeh, S. [Shiraz Univ. (Iran, Islamic Republic of); Kardan, M.R.; Abdollah Miangi, F.; Rastkhah, N. [National Radiation Protection Dept., Tehran (Iran, Islamic Republic of)

2006-07-01

This paper discusses an incident occurred in one of the radiation application centers in Iran, and follow up investigations as well as lessons learnt. In January 2004 the Regulatory Authority was informed through Shiraz University R.P.O. of an incident regarding orphan radioactive sources which belonged to a Radiation Application Center (R.A.C.) in Shiraz. In this incident a metallic box containing a neutron emitting and three gamma emitting sources belonging to the above mentioned center were unearthed from a burial site outside of Shiraz by some person or persons and the box was eventually set on fire. Investigations conducted later on, showed that despite the melting of the paraffin shield of neutron emitting source, the capsules containing sources were intact and unharmed, and no radioactive leaking had occurred. Further investigations showed that this box contained one Am-Be source and three Cs-137 sources which had been given to the above mentioned center, long time before by a foreign well logging company from former Czech Republic and without notifying the Regulatory Authority. Follow up measurements indicated the maximum dose rate of 111 GBq Am-Be and 3.7 GBq Cs-137 sources to be 13 mSv/h and 7 mSv/hr accordingly. Therefore the maximum dose for the people involved in this incident is estimated to have been about 100 mSv, consequently no severe deterministic effects to individuals is expected: the findings showed that the main reasons for the incident were as follows: 1. Lack of professionalism in working with radioactive materials. 2. Violation of obligation under Radiation protection act and related regulations by the owner of the sources which was a well logging foreign company. 3. Leaving the sources in an improper storage condition. 4. Unauthorized access to the radiation sources in the owner center. 5. Lack of an effective national register system in the Regulatory Authority. 6. Lack of a well scheduled and risk base inspection program for the

Health effects of radiation and the implications for radiation safety

International Nuclear Information System (INIS)

Gonzalez, A.J.; Anderer, J.

1991-01-01

In this Paper two elements of a multiphase analysis of radiation exposures in the living environment - the human health effects of ionizing radiation and the implications for radiation safety policy and practices - are presented. Part 1 draws together the current state of scientific knowledge and insight about the human health effects of radiation, describing these in terms of known cause-related deterministic effects and of the estimated incidence of stochastic effects as defined by biostatistics and biological models. The 1988 UNSCEAR report provides an authoritative basis for such an examination. Part 2 explores some of the major implications that the state-of-the-art of radiation biology has - or should have - for radiation safety policy and practices. (author)

Investigation of the possible increased incidence of cancer in West Cumbria

International Nuclear Information System (INIS)

Rubery, E.D.

1985-01-01

The report of the Black Advisory Group on an investigation of the possible increased incidence of cancer in West Cumbria is briefly considered. The Advisory Group was unable to reach definite conclusions as to whether there is a link between discharges of radioactive material from BNFL Sellafield and the incidence of cancer due to uncertainties in the available epidemiological data and the radiation dose estimate data. The implementation of ten recommendations of the Black Advisory Group are briefly described covering epidemiological, radiation protection and organisational matters in an effort to clarify the situation and to enhance public safety. (U.K.)

Solid state radiation detector system

International Nuclear Information System (INIS)

1977-01-01

A solid state radiation flux detector system utilizes a detector element, consisting of a bar of semiconductor having electrical conductance of magnitude dependent upon the magnitude of photon and charged particle flux impinging thereon, and negative feedback circuitry for adjusting the current flow through a light emitting diode to facilitate the addition of optical flux, having a magnitude decreasing in proportion to any increase in the magnitude of radiation (e.g. x-ray) flux incident upon the detector element, whereby the conductance of the detector element is maintained essentially constant. The light emitting diode also illuminates a photodiode to generate a detector output having a stable, highly linear response with time and incident radiation flux changes

Gamma-ray lines from radiative dark matter decay

International Nuclear Information System (INIS)

Garny, Mathias; Ibarra, Alejandro; Tran, David; Weniger, Christoph

2011-01-01

The decay of dark matter particles which are coupled predominantly to charged leptons has been proposed as a possible origin of excess high-energy positrons and electrons observed by cosmic-ray telescopes PAMELA and Fermi LAT. Even though the dark matter itself is electrically neutral, the tree-level decay of dark matter into charged lepton pairs will generically induce radiative two-body decays of dark matter at the quantum level. Using an effective theory of leptophilic dark matter decay, we calculate the rates of radiative two-body decays for scalar and fermionic dark matter particles. Due to the absence of astrophysical sources of monochromatic gamma rays, the observation of a line in the diffuse gamma-ray spectrum would constitute a strong indication of a particle physics origin of these photons. We estimate the intensity of the gamma-ray line that may be present in the energy range of a few TeV if the dark matter decay interpretation of the leptonic cosmic-ray anomalies is correct and comment on observational prospects of present and future Imaging Cherenkov Telescopes, in particular the CTA

Radiation-attenuated vaccine for lungworm disease

International Nuclear Information System (INIS)

Singh, C.M.

1977-01-01

The work done at the Indian Veternary Research Institute, Izatnagar, on the development of a vaccine for lungworm diseases is reported. Research work done includes: (1) studies on the epidemiology and the incidence of the lungworm infections, (ii) studies on the radiation-attenuated lungworm Dictyocaulus filaria vaccine, (iii) studies on other parasites using ionizing radiation, (iv) incidence of lungworm infection in sheep in Jammu and Kashmir State, (v) suitable dose of gamma radiation for attenuation, (vi) laboratory studies with radiation-attenuated D. filaria vaccine, (vii) serology of D. filaria infection, (viii) field trials with the radiation-attenuated vaccine, (ix) immune response of previously exposed lambs to vaccination, (x) comparative susceptibility of sheep and goats to infection with D. filaria, (xi) quantitative studies of D. filaria in lambs and (xii) production and supply of lungworm vaccine. (A.K.)

Radiation Practices. Annual Report 2005

International Nuclear Information System (INIS)

Rantanen, E.

2006-06-01

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

Wave-flume experiments of soft-rock cliff erosion under monochromatic waves

Science.gov (United States)

Regard, Vincent; Astruc, Dominique; Caplain, Bastien

2017-04-01

We investigate how cliffs erode under wave attack. Rocky coast erosion works through cycles, each one corresponding to three successive phases: (i) notch creation at cliff toe by mechanical action of waves, (ii) cliff fracturation leading to collapse, and (iii) evacuation of scree aprons by waves and currents. We performed experiments in a 5m x 14cm x 25cm wave flume (15 cm water depth) to investigate how waves are eroding a rocky coast. The cliff is made of wet sand and models a relatively soft rock. We used 3 different grain size (D50 = 0.28-0.41-0.48 mm), changing the cliff rheology. Waves are monochromatic; their height and period differ for the various experiments. Actual wave parameters are estimated by capacitive probes located offshore. The experiments are monitored by two video cameras both on the side and above the flume. Pictures are taken at a rate of 1Hz during the first 4h and then the rate is decreased to 0.1Hz till the end of experiment (about 1 day). The monitoring ensure a confident characterization of experiments in terms of waves (surf similarity parameter ξ and the incident wave energy flux F) and in terms of sediment (Dean number Ω and Shields number θb at breakers). Experiments begin by an initial phase of quick cliff retreat. Then the system evolves with slower cliff retreat. We focus on bottom morphology which we characterize in function of wave forcing (ξ, F). We show that the bottom morphology mainly depends on ξ. For our reference sediment (Dm = 0.41 mm), we observed: (i) surging breakers on a steep terrace (type T1) for ξ > 0.65; (ii)collapsing breakers on a bared profile attached to the inner platform (type T2) for 0.55< ξ <0.6; (iii) spilling breakers on gentle terrace (type T3) for F < 1.3 W/m and 0.55< ξ <0.6. Another bottom morphology, type T4, displays two sub-systems, an outer system with a double-bar profile where breaking waves are plunging, and an inner system with a T1, T2 or T3 profile. Some of these bottom

Undulator commissioning by characterization of radiation in x-ray free electron lasers

Directory of Open Access Journals (Sweden)

Takashi Tanaka

2012-11-01

Full Text Available In x-ray free electron lasers (XFELs where a long undulator composed of many segments is installed, there exist a number of error sources to reduce the FEL gain such as the trajectory error, K value discrepancy, and phase mismatch, which are related to the segmented-undulator structure. Undulator commissioning, which refers to the tuning and alignment processes to eliminate the possible error sources, is thus an important step toward realization of lasing. In the SPring-8 angstrom compact free electron laser (SACLA facility, the undulator commissioning has been carried out by means of characterization of x-ray radiation, i.e., measurements of the spatial and spectral profiles of monochromatized spontaneous undulator radiation as well as by probing the FEL intensity. The achieved tuning and alignment accuracies estimated from the statistics of actual measurements in SACLA show the effectiveness of this commissioning scheme.

Effect of contamination on gynecological disease incidence in women

International Nuclear Information System (INIS)

Agamova, K.A.; Sotnikova, E.N.; Gladunova, Z.D.; Novikova, E.G.; Aleksandrova, L.M.

1995-01-01

Epithelial tissues of neck of the womb, cervical canal and endometritis in women residing on the territories with increased radiation background after the Chernobyl accident have been examined. The cytologic diagnosis method employed demonstrated a high information content. Incidence of background, precancer and inflammatory processes has been ascertained in compliance with cytological classification. Cytomorphological signs of possible radiation-induced injury of cells have been studied

Radiation practices. Annual report 2011

Energy Technology Data Exchange (ETDEWEB)

Rantanen, E. (ed.)

2012-09-15

conducted by an international expert group. There were 46 abnormal incidents involving the use of radiation in 2011. 13 of these incidents concerned the use of radiation in industry, research and education, 29 involved medical uses of radiation, 1 arose in transportation of radiation sources and 3 concerned the use of non-ionizing radiation. None of these incidents had serious consequences. (orig.)

Resources planning for radiological incidents management

Science.gov (United States)

Hamid, Amy Hamijah binti Ab.; Rozan, Mohd Zaidi Abd; Ibrahim, Roliana; Deris, Safaai; Yunus, Muhd. Noor Muhd.

2017-01-01

Disastrous radiation and nuclear meltdown require an intricate scale of emergency health and social care capacity planning framework. In Malaysia, multiple agencies are responsible for implementing radiological and nuclear safety and security. This research project focused on the Radiological Trauma Triage (RTT) System. This system applies patient's classification based on their injury and level of radiation sickness. This classification prioritizes on the diagnostic and treatment of the casualties which include resources estimation of the medical delivery system supply and demand. Also, this system consists of the leading rescue agency organization and disaster coordinator, as well as the technical support and radiological medical response teams. This research implemented and developed the resources planning simulator for radiological incidents management. The objective of the simulator is to assist the authorities in planning their resources while managing the radiological incidents within the Internal Treatment Area (ITA), Reception Area Treatment (RAT) and Hospital Care Treatment (HCT) phases. The majority (75%) of the stakeholders and experts, who had been interviewed, witnessed and accepted that the simulator would be effective to resolve various types of disaster and resources management issues.

Modification of radiation carcinogenesis by marihuana

International Nuclear Information System (INIS)

Montour, J.L.; Dutz, W.; Harris, L.S.

1981-01-01

Male, female, and ovariectomized female Sprague-Dawley rats were irradiated with 400 rads, 150 rads, or 300 rads, respectively, of 60 Co gamma rays when they were between 40 and 50 days of age. The animals were injected three times weekly with either marihuana extract or with alcohol-emulphor carrier. Comparable unirradiated groups were similarly injected. Mean survival time in males was significantly shorter in the 400 rad + marihuana group compared with the three other groups whose mean survival times did not differ. Through the 546 days that the males were observed, the total number of tumors other than fibrosarcomas was significantly greater following radiation and marihuana (22) than radiation alone (6). Fifteen of the tumors were of breast or endocrine tissues. No differences were seen in the unirradiated groups. In the females, which were observed for 635 days, the total number of breast tumors was greater with the combined treatment (38) compared with radiation alone (22). This was entirely due to a marked difference in the adenocarcinoma incidence, which was 21 (radiation + marihuana) compared with four (radiation alone). The number of adenofibromas was similar in the two groups. In the unirradiated female groups the breast adenocarcinoma incidence was eight in the marihuana group and two in the control group. Ovariectomy resulted in a lower breast tumor incidence in all groups. Nonbreast tumors were more frequent in the ovariectomized-irradiated groups. Radiation plus marihuana produced more nonbreast tumors (25) than radiation alone (17) in the ovariectomized females

Modification of radiation carcinogenesis by marijuana

International Nuclear Information System (INIS)

Montour, J.L.; Dutz, W.; Harris, L.S.

1981-01-01

Male, female, and ovariectomized female Sprague-Dawley rats were irradiated with 400 rads, 150 rads, or 300 rads, respectively, of 60 Co gamma rays when they were between 40 and 50 days of age. The animals were injected three times weekly with either marihuana extract or with alcohol-emulphor carrier. Comparable unirradiated groups were similarly injected. Mean survival time in males was significantly shorter in the 400 rad + marihuana group compared with the three other groups whose mean survival times did not differ. Through the 546 days that the males were observed, the total number of tumors other than fibrosarcomas was significantly greater following radiation and marihuana (22) than radiation alone (6). Fifteen of the tumors were of breast or endocrine tissues. No differences were seen in the unirradiated groups. In the females, which were observed for 635 days, the total number of breast tumors was greater with the combined treatment (38) compared with radiation alone (22). This was entirely due to a marked difference in the adenocarcinoma incidence, which was 21 (radiation + marihuana) compared with four (radiation alone). The number of adenofibromas was similar in the two groups. In the unirradiated female groups the breast adenocarcinoma incidence was eight in the marihuana group and two in the control group. Ovariectomy resulted in a lower breast tumor incidence in all groups. Nonbreast tumors were more frequent in the ovariectomized-irradiated groups. Radiation plus marihuana produced more nonbreast tumors (25) than radiation alone (17) in the ovariectomized females

A compact design for monochromatic OSL measurements in the wavelength range 380-1020 NM

DEFF Research Database (Denmark)

Bøtter-Jensen, L.; Poolton, N.R.J.; Willumsen, F.

1994-01-01

automated Riso TL/OSL dating apparatus, thus allowing for either routine scanning or more detailed thermo-optical investigations. The high throughput efficiency of the unit means that the existing 75 W tungsten-halogen lamp can be directly used for such measurements on both quartz and feldspar samples......The development and performance of a compact module is described that allows for the monochromatic illumination of samples in the wavelength range 380-1020 nm, enabling the measurement of energy-resolved optically stimulated luminescence. The unit is designed to couple directly to the existing....... The design allows for rapid spectral scanning with a choice of resolution of anywhere between 10 and 80 nm: stray light levels are less than 0.01%. The unit can equally be used for recording wavelength-resolved emission spectra, whether photo-excited or thermally stimulated; the capabilities of the system...

Exposure of vitamins to UVB and UVA radiation generates singlet oxygen.

Science.gov (United States)

Knak, Alena; Regensburger, Johannes; Maisch, Tim; Bäumler, Wolfgang

2014-05-01

Deleterious effects of UV radiation in tissue are usually attributed to different mechanisms. Absorption of UVB radiation in cell constituents like DNA causes photochemical reactions. Absorption of UVA radiation in endogenous photosensitizers like vitamins generates singlet oxygen via photosensitized reactions. We investigated two further mechanisms that might be involved in UV mediated cell tissue damage. Firstly, UVB radiation and vitamins also generate singlet oxygen. Secondly, UVB radiation may change the chemical structure of vitamins that may change the role of such endogenous photosensitizers in UVA mediated mechanisms. Vitamins were irradiated in solution using monochromatic UVB (308 nm) or UVA (330, 355, or 370 nm) radiation. Singlet oxygen was directly detected and quantified by its luminescence at 1270 nm. All investigated molecules generated singlet oxygen with a quantum yield ranging from 0.007 (vitamin D3) to 0.64 (nicotinamide) independent of the excitation wavelength. Moreover, pre-irradiation of vitamins with UVB changed their absorption in the UVB and UVA spectral range. Subsequently, molecules such as vitamin E and vitamin K1, which normally exhibit no singlet oxygen generation in the UVA, now produce singlet oxygen when exposed to UVA at 355 nm. This interplay of different UV sources is inevitable when applying serial or parallel irradiation with UVA and UVB in experiments in vitro. These results should be of particular importance for parallel irradiation with UVA and UVB in vivo, e.g. when exposing the skin to solar radiation.

Avoiding radioactive accidents in Israel 1996-1997: summary of incidents occurred

Energy Technology Data Exchange (ETDEWEB)

Keren, M.; Neeman, E.; Rosental, J.J.; Brenner, S. [Tel Aviv Univ. (Israel). Medical School

1997-12-31

Radiation Safety Division of the Ministry of the Environment is responsible for radiation protection of the Israeli public and environment from radiation hazards. Notification, justification, registration and ALARA principles are important requirements to get license to use radioactive materials or instrumentation. Some incidents investigated from January 96 to the end of June 97 by the Chief National Radiation Safety Officer (CNRSO) of the division are reported 1 tab,; e-mail: envirad at post.tau.ac.il; env{sub r}ad.netvision.net.il

Relative efficiency calibration between two silicon drift detectors performed with a monochromatized X-ray generator over the 0.1-1.5 keV range

Science.gov (United States)

Hubert, S.; Boubault, F.

2018-03-01

In this article, we present the first X-ray calibration performed over the 0.1-1.5 keV spectral range by means of a soft X-ray Manson source and the monochromator SYMPAX. This monochromator, based on a classical Rowland geometry, presents the novelty to be able to board simultaneously two detectors and move them under vacuum in front of the exit slit of the monochromatizing stage. This provides the great advantage to perform radiometric measurements of the monochromatic X-ray photon flux with one reference detector while calibrating another X-ray detector. To achieve this, at least one secondary standard must be operated with SYMPAX. This paper presents thereby an efficiency transfer experiment between a secondary standard silicon drift detector (SDD), previously calibrated on BESSY II synchrotron Facility, and another one ("unknown" SDD), devoted to be used permanently with SYMPAX. The associated calibration process is described as well as corresponding results. Comparison with calibrated measurements performed at the Physikalisch-Technische Bundesanstalt (PTB) Radiometric Laboratory shows a very good agreement between the secondary standard and the unknown SDD.

Safe management of spent radiation source

International Nuclear Information System (INIS)

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

2003-01-01

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

A synchrotron-based X-ray exposure station for radiation biology experiments

International Nuclear Information System (INIS)

Thompson, A.C.; Blakely, E.A.; Bjornstad, K.A.; Chang, P.Y.; Rosen, C.J.; Schwarz, R.I.

2007-01-01

Synchrotron X-ray sources enable radiation biology experiments that are difficult with conventional sources. A synchrotron source can easily deliver a monochromatic, tunable energy, highly collimated X-ray beam of well-calibrated intensity. An exposure station at beamline 10.3.1 of the Advanced Light Source (ALS) has been developed which delivers a variable energy (5-20 keV) X-ray fan beam with very sharp edges (10-90% in less than 3 μm). A series of experiments have been done with a four-well slide where a stripe (100 μm widex18 mm long) of cells in each well has been irradiated and the dose varied from well to well. With this facility we have begun a series of experiments to study cells adjacent to irradiated cells and how they respond to the damage of their neighbors. Initial results have demonstrated the advantages of using synchrotron radiation for these experiments

A synchrotron-based X-ray exposure station for radiation biology experiments

Energy Technology Data Exchange (ETDEWEB)

Thompson, A.C. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States)], E-mail: acthompson@lbl.gov; Blakely, E.A.; Bjornstad, K.A. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States); Chang, P.Y. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States); SRI International, Menlo Park, CA (United States); Rosen, C.J.; Schwarz, R.I. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States)

2007-11-11

Synchrotron X-ray sources enable radiation biology experiments that are difficult with conventional sources. A synchrotron source can easily deliver a monochromatic, tunable energy, highly collimated X-ray beam of well-calibrated intensity. An exposure station at beamline 10.3.1 of the Advanced Light Source (ALS) has been developed which delivers a variable energy (5-20 keV) X-ray fan beam with very sharp edges (10-90% in less than 3 {mu}m). A series of experiments have been done with a four-well slide where a stripe (100 {mu}m widex18 mm long) of cells in each well has been irradiated and the dose varied from well to well. With this facility we have begun a series of experiments to study cells adjacent to irradiated cells and how they respond to the damage of their neighbors. Initial results have demonstrated the advantages of using synchrotron radiation for these experiments.

General Purpose Fortran Program for Discrete-Ordinate-Method Radiative Transfer in Scattering and Emitting Layered Media: An Update of DISORT

Science.gov (United States)

Tsay, Si-Chee; Stamnes, Knut; Wiscombe, Warren; Laszlo, Istvan; Einaudi, Franco (Technical Monitor)

2000-01-01

This update reports a state-of-the-art discrete ordinate algorithm for monochromatic unpolarized radiative transfer in non-isothermal, vertically inhomogeneous, but horizontally homogeneous media. The physical processes included are Planckian thermal emission, scattering with arbitrary phase function, absorption, and surface bidirectional reflection. The system may be driven by parallel or isotropic diffuse radiation incident at the top boundary, as well as by internal thermal sources and thermal emission from the boundaries. Radiances, fluxes, and mean intensities are returned at user-specified angles and levels. DISORT has enjoyed considerable popularity in the atmospheric science and other communities since its introduction in 1988. Several new DISORT features are described in this update: intensity correction algorithms designed to compensate for the 8-M forward-peak scaling and obtain accurate intensities even in low orders of approximation; a more general surface bidirectional reflection option; and an exponential-linear approximation of the Planck function allowing more accurate solutions in the presence of large temperature gradients. DISORT has been designed to be an exemplar of good scientific software as well as a program of intrinsic utility. An extraordinary effort has been made to make it numerically well-conditioned, error-resistant, and user-friendly, and to take advantage of robust existing software tools. A thorough test suite is provided to verify the program both against published results, and for consistency where there are no published results. This careful attention to software design has been just as important in DISORT's popularity as its powerful algorithmic content.

The incidence of radiation necrosis following stereotactic radiotherapy for melanoma brain metastases: the potential impact of immunotherapy.

Science.gov (United States)

Kaidar-Person, Orit; Zagar, Timothy M; Deal, Allison; Moschos, Stergios J; Ewend, Matthew G; Sasaki-Adams, Deanna; Lee, Carrie B; Collichio, Frances A; Fried, David; Marks, Lawrence B; Chera, Bhishamjit S

2017-07-01

Stereotactic radiotherapy (SRT) is the standard treatment for patients with limited number of brain metastases. In the past few years, newer immunotherapies (immune checkpoint inhibitors) have been proven to prolong survival in patients with metastatic melanoma. The safety of the combination of SRT and immunotherapy for brain metastases is unknown. We retrospectively identified patients with melanoma brain metastases treated with SRT between 2007 and 2015. Patients who did not have at least 3 months of follow-up with imaging after SRT were excluded from the analysis. Outcomes were compared between patients who were treated with or without immunotherapy. A total of 58 patients were included; of these, 29 were treated with SRT and immunotherapy. MAPK inhibitors (BRAF, MEK inhibitors) were used more often in the immunotherapy group (nine vs. two patients). There was a higher incidence of intracranial complications in patients treated with immunotherapy and SRT. Eight patients had radiation necrosis; all occurred in patients who were treated with immunotherapy. Nine patients had hemorrhage, of which seven occurred in patients who were treated with immunotherapy (P=0.08). However, patients treated with immunotherapy and SRT had a significant overall survival advantage compared with SRT without immunotherapy (15 vs. 6 months, P=0.0013). Patients treated with SRT and immunotherapy have a higher incidence/risk of intracranial complications, but a longer overall survival.

Radiation Practices. Annual Report 2003

International Nuclear Information System (INIS)

Rantanen, E.

2004-01-01

2003, STUK investigated 15 abnormal incidents involving the use of radiation. Eight of these incidents concerned the use of radiation in industry, research and education, six involved medical uses of radiation and one concerned the use of non-ionizing radiation. None of these incidents resulted in serious consequences. (orig.)

GLERL Radiation Transfer Through Freshwater Ice

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Radiation transmittance (ratio of transmitted to incident radiation) through clear ice, refrozen slush ice and brash ice, from ice surface to ice-water interface in...

Radiation tolerance of the cervical spinal cord

International Nuclear Information System (INIS)

McCunniff, A.J.; Liang, M.J.

1989-01-01

The incidence of permanent injury to the spinal cord as a complication of radiation therapy generally correlates positively with total radiation dosage. However, several reports in the literature have indicated that fraction size is also an important factor in the development or nondevelopment of late injuries in normal tissue. To determine the effect of fraction size on the incidence of radiation-induced spinal cord injuries, we reviewed 144 cases of head and neck cancer treated at our institution between 1971 and 1980 with radiation greater than 5600 cGy to a portion of the cervical spinal cord. Most of these patients received greater than or equal to 6000 cGy, with fraction sizes ranging from 133 cGy to 200 cGy. Fifty-three of the 144 patients have been followed up for 2 years or more. Nearly half of these (26 patients) received greater than 6000 cGy with fraction sizes of 133 cGy to 180 cGy. Only 1 of the 53 (1.9%) has sustained permanent spinal cord injury; 20 months after completion of radiation treatments he developed Brown-Sequard syndrome. Our experience suggests that radiation injuries to the spinal cord correlate not only with total radiation dosage, but also with fraction size; low fraction sizes appear to decrease the incidence of such injuries

Indoor ionizing radiation

International Nuclear Information System (INIS)

Ericson, S.O.; Lindvall, T.; Maansson, L-G.

1986-01-01

Radiation in indoor air is discussed in the perspective of the effective dose equivalents from other sources of radiation. Estimates of effective doses equivalents from indoor radon and its contribution to lung cancer incidence are reviewed. Swedish experiences with cost effective remedial actions are presented. The authors present optimal strategies for screening measurements and remedial actions in cost-benefit perspective. (author.)

Solar radiation in forest and pasture areas in the Amazonia

International Nuclear Information System (INIS)

Feitosa, J.R.P.; Costa, R.F. da; Fisch, G.; Souza, S.S. de; Nobre, C.A.

1998-01-01

The average daytime behavior of the global incident radiation (Rg) over grassland (NS) and forest (RJ) in Rondonia State during dry and wet seasons were analyzed. The data set originated from the ABRACOS Project’s automatic meteorological stations in years 1992 through 1996. Results showed that incident radiation is smaller in pasture than in forest (17.1MJ m -2 dia -1 pasture versus 18.3M Jm -2 dia -1 forest) during the dry season. In the wet season, incident radiation is smaller than dry season, with 16.9MJ m -2 dia -1 for pasture and 17.1MJ m -2 dia -1 for forest. Atmospheric transmittance in pasture was smaller than forest (0.58 versus 0.66) in the dry season. This difference is equivalent a reduction of 2.8M Jm -2 dia -1 in the surface incident radiation. In the wet season the transmittances were 0.52 for the pasture and 0.50 for the forest. (author) [pt

Studies and comparisons of two photon-tagging systems for the production of monochromatic photon beams for photonuclear experiments

International Nuclear Information System (INIS)

Aniel, Thierry.

1982-06-01

The performance of photon beams obtained by two different tagging processes (tagging of ''hard'' annihilation photons with ''soft'' associated photons, tagging of bremstrahlung photons with associated electrons) on the same facility was studied. The two processes are described and experimental results on the characteristics of the resulting beams given. The respective advantages of both methods are compared with one another and with those of a quasi-monochromatic beam obtained by the in-flight annihilation of a positron beam. A development based on the second process is then studied together with its applications to photonuclear physics [fr

Monitoring System For Improving Radiation Safety Management

International Nuclear Information System (INIS)

Osovizky, A.; Paran, J.; Tal, N.; Ankry, N.; Ashkenazi, B.; Tirosh, D.; Marziano, R.; Chisin, R.

1999-01-01

Medi SMARTS (Medical Survey Mapping Automatic Radiation Tracing System), a gamma radiation monitoring system, was installed in a nuclear medicine department. In this paper the evaluation of the system's ability to improve radiation safety management is presented. The system is based on a state of the art software that continuously collects on line radiation measurements for display, analysis and logging. Radiation is measured by GM tubes; the signal is transferred to a data processing unit and then via an RS-485 communication line to a computer. The system automatically identifies the detector type and its calibration factor, thus providing compatibility, maintainability and versatility when changing detectors. Radiation levels are displayed on the nuclear medicine department map at six locations. The system has been operating continuously for more than one year, documenting abnormal events caused by routine operation or failure incidents. In cases where abnormal working conditions were encountered, an alarm message was sent automatically to the supervisor via his tele-pager. An interesting issue observed during the system evaluation, was the inability to distinguish between high radiation levels caused by proper routine operation and those caused by safety failure incidents. The solution included examination of two parameters, radiation levels as well as their duration period. A careful analysis of the historical data, applying the appropriated combined parameters determined for each location, verified that such a system can identify abnormal events, provide alarms to warn in case of incidents and improve standard operating procedures

Radiation detector arrangements and methods

International Nuclear Information System (INIS)

Jackson, J.

1989-01-01

The patent describes a radiation detector arrangement. It comprises at least one detector element in the form of a temperature-sensitive resistor whose electrical resistance changes in response to radiation incident on the detector element, the resistor having a high positive temperature coefficient of electrical resistance at a transition in its electrical conductance, circuit means for applying a voltage across the resistor during operation of the detector arrangement, and temperature-regulation means for regulating the temperature of the resistor so as to operate the resistor in the transition, characterised in that the temperature-regulation means comprises the resistor and the circuit means which passes sufficient current through the resistor by resistance heating to a position in the transition at which a further increase in its temperature in response to incident radiation reduces the resistance heating by reducing the current, thereby stabilizing the temperature of the resistor at the position. The positive temperature coefficient at the position being sufficiently high that the change in the resistance heating produced by a change in the temperature of the resistor at the position is larger than a change in power of the incident radiation required to produce that same change in temperature of the resistor in the absence of any change in resistance heating