Experiment on direct nn scattering - The radiation-induced outgassing complication

Energy Technology Data Exchange (ETDEWEB)

Stephenson, S.L., E-mail: sstephen@gettysburg.edu [Gettysburg College, Gettysburg, PA 17325 (United States); Crawford, B.E. [Gettysburg College, Gettysburg, PA 17325 (United States); Furman, W.I.; Lychagin, E.V.; Muzichka, A.Yu.; Nekhaev, G.V.; Sharapov, E.I.; Shvetsov, V.N.; Strelkov, A.V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Levakov, B.G.; Lyzhin, A.E.; Chernukhin, Yu.I. [Russian Federal Nuclear Center - All Russian Research Institute of Technical Physics, P.O. Box 245, 456770 Snezhinsk (Russian Federation); Howell, C.R. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Mitchell, G.E. [North Carolina State University, Raleigh, NC 27695-8202 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Tornow, W. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Showalter-Bucher, R.A. [Northeastern University, Boston, MA 02115 (United States)

2012-12-01

The first direct neutron-neutron scattering experiment using the YAGUAR pulsed reactor has yielded initial results. They show a unforeseen significant thermal neutron background as a result of radiation-induced desorption within the scattering chamber. Thermal neutrons are mostly scattering not from other neutrons but instead from the desorbed gas molecules. Analysis of the obtained neutron time-of-flight spectra suggests neutron scattering from H{sub 2} molecules. The presented desorption model agrees with our experimental value of the desorption yield {eta}{sub {gamma}}=0.02 molecules/gamma. Possible techniques to reduce the effect of the desorption background are presented.

Validation of MCNP4A for repository scattered radiation analysis

International Nuclear Information System (INIS)

Haas, M.N.; Su, S.

1998-02-01

Comparison is made between experimentally determined albedo (scattered) radiation and MCNP4A predictions in order to provide independent validation for repository shielding analysis. Both neutron and gamma scattered radiation fields from concrete ducts are compared in this paper. Satisfactory agreement is found between actual and calculated results with conservative values calculated by the MCNP4A code for all conditions

Consequences of the factorization hypothesis in nucleon-nucleon, $\\gamma p and \\gamma \\gamma$ scattering

CERN Document Server

Block, Martin M

2002-01-01

Using an eikonal structure for the scattering amplitude, factorization theorems for nucleon-nucleon, gamma p and gamma gamma scattering at high energies have been derived, using only some very general assumptions. Using a QCD-inspired eikonal analysis of nucleon-nucleon scattering, we present here experimental confirmation for factorization of cross sections, nuclear slope parameters B and rho -values (ratio of real to imaginary portion of forward scattering amplitudes), showing that: 1) the three factorization theorems of Block and Kaidalov [2000] hold, 2) the additive quark model holds to approximately=1%, and 3) vector dominance holds to better than approximately=4%. Predictions for the total cross section, elastic cross section and other forward scattering parameters at the LHC (14 TeV) are given. (12 refs).

Density measurement by means of once scattered gamma radiation the ETG probe, principles and equipment

International Nuclear Information System (INIS)

Joergensen, J.L.; Oelgaard, P.L.; Berg, F.

1987-01-01

The Department of Electrophysics, the Technical University of Denmark, and the Danish National Road Laboratory have together developed a new patent claimed device for measurements of the in situ density of materials. This report describes the principles of the system and some experimental results. The system is based on the once scattered gamma radiation. In a totally non-destructive and fast way it is possible to measure the density of up to 25 cm thick layers. Furthermore, an estimate of the density variation through the layer may be obtained. Thus the gauge represents a new generation of equipment for e.g. compaction control of road constructions. (author)

Detection of gamma-neutron radiation by solid-state scintillation detectors. Detection of gamma-neutron radiation by novel solid-state scintillation detectors

Energy Technology Data Exchange (ETDEWEB)

Ryzhikov, V.; Grinyov, B.; Piven, L.; Onyshchenko, G.; Sidletskiy, O. [Institute for Scintillation Materials of the NAS of Ukraine, Kharkov, (Ukraine); Naydenov, S. [Institute for Single Crystals of the National Academy of Sciences of Ukraine, Kharkov, (Ukraine); Pochet, T. [DETEC-Europe, Vannes (France); Smith, C. [Naval Postgraduate School, Monterey, CA (United States)

2015-07-01

It is known that solid-state scintillators can be used for detection of both gamma radiation and neutron flux. In the past, neutron detection efficiencies of such solid-state scintillators did not exceed 5-7%. At the same time it is known that the detection efficiency of the gamma-neutron radiation characteristic of nuclear fissionable materials is by an order of magnitude higher than the efficiency of detection of neutron fluxes alone. Thus, an important objective is the creation of detection systems that are both highly efficient in gamma-neutron detection and also capable of exhibiting high gamma suppression for use in the role of detection of neutron radiation. In this work, we present the results of our experimental and theoretical studies on the detection efficiency of fast neutrons from a {sup 239}Pu-Be source by the heavy oxide scintillators BGO, GSO, CWO and ZWO, as well as ZnSe(Te, O). The most probable mechanism of fast neutron interaction with nuclei of heavy oxide scintillators is the inelastic scattering (n, n'γ) reaction. In our work, fast neutron detection efficiencies were determined by the method of internal counting of gamma-quanta that emerge in the scintillator from (n, n''γ) reactions on scintillator nuclei with the resulting gamma energies of ∼20-300 keV. The measured efficiency of neutron detection for the scintillation crystals we considered was ∼40-50 %. The present work included a detailed analysis of detection efficiency as a function of detector and area of the working surface, as well as a search for new ways to create larger-sized detectors of lower cost. As a result of our studies, we have found an unusual dependence of fast neutron detection efficiency upon thickness of the oxide scintillators. An explanation for this anomaly may involve the competition of two factors that accompany inelastic scattering on the heavy atomic nuclei. The transformation of the energy spectrum of neutrons involved in the (n, n

Determination of the gamma radiation scattering with geometry changes in the system

International Nuclear Information System (INIS)

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

1988-07-01

Three different experimental systems were used for the determination of the radiation scattering due to the walls, ceiling and floor of the Calibration Laboratory. The radiation detection was made with a portable ionization chamber Victoreen model Panoramic 470. The measurements were taken with and without the use of a lead shield block between the detector and the radioactive source. The results showed that the scattering contribution increased about 80%, as the distance between detector and source was varied from 1,0 to 2,0 m. Therefore the scattering contribution determination is very important for the establishment of the standard radiation fields for instruments calibration. (author) [pt

Compact FEL-driven inverse compton scattering gamma-ray source

Energy Technology Data Exchange (ETDEWEB)

Placidi, M. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Di Mitri, S., E-mail: simone.dimitri@elettra.eu [Elettra - Sincrotrone Trieste S.C.p.A., 34149 Basovizza, Trieste (Italy); Pellegrini, C. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); University of California, Los Angeles, CA 90095 (United States); Penn, G. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2017-05-21

Many research and applications areas require photon sources capable of producing gamma-ray beams in the multi-MeV energy range with reasonably high fluxes and compact footprints. Besides industrial, nuclear physics and security applications, a considerable interest comes from the possibility to assess the state of conservation of cultural assets like statues, columns etc., via visualization and analysis techniques using high energy photon beams. Computed Tomography scans, widely adopted in medicine at lower photon energies, presently provide high quality three-dimensional imaging in industry and museums. We explore the feasibility of a compact source of quasi-monochromatic, multi-MeV gamma-rays based on Inverse Compton Scattering (ICS) from a high intensity ultra-violet (UV) beam generated in a free-electron laser by the electron beam itself. This scheme introduces a stronger relationship between the energy of the scattered photons and that of the electron beam, resulting in a device much more compact than a classic ICS for a given scattered energy. The same electron beam is used to produce gamma-rays in the 10–20 MeV range and UV radiation in the 10–15 eV range, in a ~4×22 m{sup 2} footprint system.

Isospin breaking in pion-nucleon scattering at threshold by radiative processes

CERN Document Server

Ericson, Torleif Eric Oskar

2006-01-01

We investigate the dispersive contribution by radiative processes such as (pi- proton to neutron gamma) and (pi- proton to Delta gamma) to the pion-nucleon scattering lengths of charged pions in the heavy baryon limit. They give a large isospin violating contribution in the corresponding isoscalar scattering length, but only a small violation in the isovector one. These terms contribute 6.3(3)% to the 1s level shift of pionic hydrogen and give a chiral constant F_pi^2f_1=-25.8(8) MeV.

Application of gamma radiation backscattering in determining density and Zsub(eff) of scattering material Monte Carlo optimization of configuration

International Nuclear Information System (INIS)

Cechak, T.

1982-01-01

Applying Gardner's method of double evaluation one detector should be positioned such that its response should be independent of the material density and the second detector should be positioned so as to maximize changes in response due to density changes. The experimental scanning for optimal energy is extremely time demanding. A program was written based on the Monte Carlo method which solves the problem of error magnitude in case the computation of gamma radiation backscattering neglects multiply scattered photons, the problem of how this error depends on the atomic number of the scattering material as well as the problem of whether the representation of individual scatterings in the spectrum of backscattered photons depends on the positioning of the detector. 42 detectors, 8 types of material and 10 different density values were considered. The computed dependences are given graphically. (M.D.)

Differential sensitivity of Chironomus and human hemoglobin to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Gaikwad, Pallavi S. [Stress Biology Research Laboratory, Department of Zoology, Savitribai Phule University, Pune, 411007 (India); Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Panicker, Lata [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Mohole, Madhura; Sawant, Sangeeta [Bioinformatics Center, Savitribai Phule Pune University, Pune, 411007 (India); Mukhopadhyaya, Rita [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Nath, Bimalendu B., E-mail: bbnath@gmail.com [Stress Biology Research Laboratory, Department of Zoology, Savitribai Phule University, Pune, 411007 (India)

2016-08-05

Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively. Stability and integrity of Chironomus and human Hb to gamma radiation was compared using biophysical techniques like Dynamic Light Scattering (DLS), UV-visible spectroscopy, fluorescence spectrometry and CD spectroscopy after exposure of whole larvae, larval hemolymph, human peripheral blood, purified Chironomus and human Hb. Sequence- and structure-based bioinformatics methods were used to analyze the sequence and structural similarities or differences in the heme pockets of respective Hbs. Resistivity of Chironomus Hb to gamma radiation is remarkably higher than human Hb. Human Hb exhibited loss of heme iron at a relatively low dose of gamma radiation exposure as compared to Chironomus Hb. Unlike human Hb, the heme pocket of Chironomus Hb is rich in aromatic amino acids. Higher hydophobicity around heme pocket confers stability of Chironomus Hb compared to human Hb. Previously reported gamma radiation tolerance of Chironomus can be largely attributed to its evolutionarily ancient form of extracellular Hb as evident from the present study. -- Highlights: •Comparison of radiation tolerant Chironomus Hb and radiation sensitive Human Hb. •Amino acid composition of midge and human heme confer differential hydrophobicity. •Heme pocket of evolutionarily ancient midge Hb provide gamma radiation resistivity.

Differential sensitivity of Chironomus and human hemoglobin to gamma radiation

International Nuclear Information System (INIS)

Gaikwad, Pallavi S.; Panicker, Lata; Mohole, Madhura; Sawant, Sangeeta; Mukhopadhyaya, Rita; Nath, Bimalendu B.

2016-01-01

Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively. Stability and integrity of Chironomus and human Hb to gamma radiation was compared using biophysical techniques like Dynamic Light Scattering (DLS), UV-visible spectroscopy, fluorescence spectrometry and CD spectroscopy after exposure of whole larvae, larval hemolymph, human peripheral blood, purified Chironomus and human Hb. Sequence- and structure-based bioinformatics methods were used to analyze the sequence and structural similarities or differences in the heme pockets of respective Hbs. Resistivity of Chironomus Hb to gamma radiation is remarkably higher than human Hb. Human Hb exhibited loss of heme iron at a relatively low dose of gamma radiation exposure as compared to Chironomus Hb. Unlike human Hb, the heme pocket of Chironomus Hb is rich in aromatic amino acids. Higher hydophobicity around heme pocket confers stability of Chironomus Hb compared to human Hb. Previously reported gamma radiation tolerance of Chironomus can be largely attributed to its evolutionarily ancient form of extracellular Hb as evident from the present study. -- Highlights: •Comparison of radiation tolerant Chironomus Hb and radiation sensitive Human Hb. •Amino acid composition of midge and human heme confer differential hydrophobicity. •Heme pocket of evolutionarily ancient midge Hb provide gamma radiation resistivity.

Random pulsing of neutron source for inelastic neutron scattering gamma ray spectroscopy

International Nuclear Information System (INIS)

Hertzog, R.C.

1981-01-01

Method and apparatus are described for use in the detection of inelastic neutron scattering gamma ray spectroscopy. Data acquisition efficiency is enhanced by operating a neutron generator such that a resulting output burst of fast neutrons is maintained for as long as practicably possible until a gamma ray is detected. Upon the detection of a gamma ray the generator burst output is terminated. Pulsing of the generator may be accomplished either by controlling the burst period relative to the burst interval to achieve a constant duty cycle for the operation of the generator or by maintaining the burst period constant and controlling the burst interval such that the resulting mean burst interval corresponds to a burst time interval which reduces contributions to the detected radiation of radiation occasioned by other than the fast neutrons

Measurement and Calculation of Gamma Radiation from HWZPR Reactor

International Nuclear Information System (INIS)

Jalali, Majid

2006-01-01

HWZPR is a research reactor with natural uranium fuel, D 2 O moderator and graphite reflector with maximum power of 100 W. It is a suitable means for theoretical research and heavy water reactor experiments. Neutrons from the core participate in different nuclear reactions by interactions with fuel, moderator, graphite and the concrete around the reactor. The results of these interactions are the production of prompt gammas in the environment. Useful information is gained by the reactor gamma spectrum measurement from point of view of relative quantity and energy distribution of direct and scattered radiations. Reactor gamma ray spectrum has been gathered in different places around the reactor by HPGe detector. In analysis of these spectra, 1 H(n,γ) 2 H, 16 O(n,n'γ) 16 O, 2 H(n,γ) 3 H and 238 U(n,γ) 239 U reactions occurring in reactor moderator and fuel, are important. The measured spectrum has been primarily estimated by the MCNP code. There is agreement between the code and the experiments in some points. The scattered gamma rays from 27 Al (n,γ) 28 Al reaction in the reactor tank, are the most among the gammas scattered in the reactor environment. Also the dose calculations by MCNP code show that 72% of gamma dose belongs to the energy range 3-11 MeV from reactor gamma spectrum and the danger of exposure from the reactor high-energy photons is serious. (author)

Poster - 11: Radiation barrier thickness calculations for the GammaPod

International Nuclear Information System (INIS)

La Russa, Daniel; Vandervoort, Eric; Wilkins, David

2016-01-01

A consortium of radiotherapy centers in North America is in the process of evaluating a novel new 60 Co teletherapy device, called the GammaPod™ (Xcision Medical Systems, Columbia Maryland), designed specifically for breast SBRT. The GammaPod consists of 36 collimated 60 Co sources with a total activity of 4320 Ci. The sources are housed in a hemispherical source carrier that rotates during treatment to produce a cylindrically symmetric cone of primary beam spanning 16° – 54° degrees from the horizontal. This unique beam geometry presents challenges when designing or evaluating room shielding for the purposes of meeting regulatory requirements, and for ensuring the safety of staff and the public in surrounding areas. Conventional methods for calculating radiation barrier thicknesses have been adapted so that barrier transmission factors for the GammaPod can be determined from a few relevant distances and characteristics of the primary beam. Simple formalisms have been determined for estimating shielding requirements for primary radiation (with a rotating and non-rotating source carrier), patient-scattered radiation, and leakage radiation. When making worst case assumptions, it was found that conventional barrier thicknesses associated with linac treatment suites are sufficient for shielding all sources of radiation from the GammaPod.

Poster - 11: Radiation barrier thickness calculations for the GammaPod

Energy Technology Data Exchange (ETDEWEB)

La Russa, Daniel; Vandervoort, Eric; Wilkins, David [Radiation Medicine Program, The Ottawa Hospital (Canada)

2016-08-15

A consortium of radiotherapy centers in North America is in the process of evaluating a novel new {sup 60}Co teletherapy device, called the GammaPod™ (Xcision Medical Systems, Columbia Maryland), designed specifically for breast SBRT. The GammaPod consists of 36 collimated {sup 60}Co sources with a total activity of 4320 Ci. The sources are housed in a hemispherical source carrier that rotates during treatment to produce a cylindrically symmetric cone of primary beam spanning 16° – 54° degrees from the horizontal. This unique beam geometry presents challenges when designing or evaluating room shielding for the purposes of meeting regulatory requirements, and for ensuring the safety of staff and the public in surrounding areas. Conventional methods for calculating radiation barrier thicknesses have been adapted so that barrier transmission factors for the GammaPod can be determined from a few relevant distances and characteristics of the primary beam. Simple formalisms have been determined for estimating shielding requirements for primary radiation (with a rotating and non-rotating source carrier), patient-scattered radiation, and leakage radiation. When making worst case assumptions, it was found that conventional barrier thicknesses associated with linac treatment suites are sufficient for shielding all sources of radiation from the GammaPod.

Influences of scattering radiation in a TLD irradiation room, 2

International Nuclear Information System (INIS)

Suzuki, Osamu; Suwa, Shigeo

1985-01-01

The influence of scattering radiation (SR) on radiation dose rate (DR) in a TLD irradiation room was assessed. A single SD from a standard TLD apparatus, i.e., an acrylic or aluminum table, was examined. The maximum DR was attained at approximately 80 cm from the radiation source. Energy spectra of SR ranged up to the energy of direct radiation beam. Circular SD at one m from the radiation source, which contributed to DR to the direct radiation beam, was almost homogeneous. SD was large near the irradiation table, and the influence of SD on DR became smaller with SD being vertically farther from the apparatus. The influence of SD on RD to the direct radiation beam became less with an increase in gamma ray energy. At one m from the radiation source, 6 - 7 % of SD contributed to DR to the direct radiation beam for 0.662 MeV of gamma ray. This figure was one half of that with NaI (Tl) scintillation detector. (Namekawa, K.)

Determining the water content in concrete by gamma scattering method

International Nuclear Information System (INIS)

Priyada, P.; Ramar, R.; Shivaramu

2014-01-01

Highlights: • Gamma scattering technique for estimation of water content in concrete is given. • The scattered intensity increases with the volumetric water content. • Attenuation correction is provided to the scattered intensities. • Volumetric water content of 137 Cs radioactive source and a high resolution HPGe detector based energy dispersive gamma ray spectrometer. Concrete samples of uniform density ≈2.4 g/cm 3 are chosen for the study and the scattered intensities found to vary with the amount of water present in the specimen. The scattered intensities are corrected for attenuation effects and the results obtained with reference to a dry sample are compared with those obtained by gravimetrical and gamma transmission methods. A good agreement is seen between gamma scattering results and those obtained by gravimetric and transmission methods within accuracy of 6% and <2% change in water content can be detected

Light scattering reviews 8 radiative transfer and light scattering

CERN Document Server

Kokhanovsky, Alexander A

2013-01-01

Light scattering review (vol 8) is aimed at the presentation of recent advances in radiative transfer and light scattering optics. The topics to be covered include: scattering of light by irregularly shaped particles suspended in atmosphere (dust, ice crystals), light scattering by particles much larger as compared the wavelength of incident radiation, atmospheric radiative forcing, astrophysical radiative transfer, radiative transfer and optical imaging in biological media, radiative transfer of polarized light, numerical aspects of radiative transfer.

Laser Compton Scattering Gamma Ray Induced Photo-Trasmutation

CERN Document Server

Li, Dazhi

2004-01-01

High brightness beams of gamma rays produced with laser Compton scattering have the potential to realize photo-transmutation through (γ,n) reaction, implying an efficient method to dispose long-lived fission products. Preliminary investigations have been carried out in understanding the feasibility of development of a transmutation facility to repose nuclear waste. A laser Compton scattering experimental setup based on a storage ring started to generate gamma-ray beams for studying the coupling of gamma photons and nuclear giant resonance. This paper demonstrates the dependency of nuclear transmutation efficiency on target dimensions and gamma ray features. 197Au sample was adopted in our experiment, and experimental results correspond to the theoretical estimations.

Gravitational scattering of electromagnetic radiation

Science.gov (United States)

Brooker, J. T.; Janis, A. I.

1980-01-01

The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-11-15

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

Cosmic ray-dark matter scattering: a new signature of (asymmetric) dark matter in the gamma ray sky

International Nuclear Information System (INIS)

Profumo, Stefano; Ubaldi, Lorenzo

2011-01-01

We consider the process of scattering of Galactic cosmic-ray electrons and protons off of dark matter with the radiation of a final-state photon. This process provides a novel way to search for Galactic dark matter with gamma rays. We argue that for a generic weakly interacting massive particle, barring effects such as co-annihilation or a velocity-dependent cross section, the gamma-ray emission from cosmic-ray scattering off of dark matter is typically smaller than that from dark matter pair-annihilation. However, if dark matter particles cannot pair-annihilate, as is the case for example in asymmetric dark matter scenarios, cosmic-ray scattering with final state photon emission provides a unique window to detect a signal from dark matter with gamma rays. We estimate the expected flux level and its spectral features for a generic supersymmetric setup, and we also discuss dipolar and luminous dark matter. We show that in some cases the gamma-ray emission might be large enough to be detectable with the Fermi Large Area Telescope

Estimation of photon energy distribution in gamma calibration field

International Nuclear Information System (INIS)

Takahashi, Fumiaki; Shimizu, Shigeru; Yamaguchi, Yasuhiro

1997-03-01

Photon survey instruments used for radiation protection are usually calibrated at gamma radiation fields, which are traceable to the national standard with regard to exposure. Whereas scattered radiations as well as primary gamma-rays exit in the calibration field, no consideration for the effect of the scattered radiations on energy distribution is given in routine calibration works. The scattered radiations can change photon energy spectra in the field, and this can result in misinterpretations of energy-dependent instrument responses. Construction materials in the field affect the energy distribution and magnitude of the scattered radiations. The geometric relationship between a gamma source and an instrument can determine the energy distribution at the calibration point. Therefore, it is essential for the assurance of quality calibration to estimate the energy spectra at the gamma calibration fields. Then, photon energy distributions at some fields in the Facility of Radiation Standard of the Japan Atomic Energy Research Institute (JAERI) were estimated by measurements using a NaI(Tl) detector and Monte Carlo calculations. It was found that the use of collimator gives a different feature in photon energy distribution. The origin of scattered radiations and the ratio of the scattered radiations to the primary gamma-rays were obtained. The results can help to improve the calibration of photon survey instruments in the JAERI. (author)

Positron annihilation radiation from the Galactic center - Cheshire cat' Compton scattering and the origin of excess continuum

International Nuclear Information System (INIS)

Bildsten, L.; Zurek, W.H.

1988-01-01

Two observations of the gamma-ray spectrum from the direction of the Galactic center were made by HEAO 3 in the fall of 1979 and the spring of 1980. The 2-gamma 511 keV annihilation line flux decreased by a factor of about three during the 6 months between these observations, while the excess gamma-ray continuum below the annihilation line, often interpreted as 3-gamma decay of orthopositronium, barely changed. This discrepancy in temporal behavior makes the identification of the bulk of excess continuum as 3-gamma decay of positronium difficult. It is shown that Compton scattering of the line and high-energy radiation provides a natural explanation for the surprisingly small changes seen in the excess continuum. Scattered photons are delayed by a time corresponding to the size of the scattering region. For the annihilation source in the Galactic center, this distance is probably a fraction of a parsec. Thus, even after the high-energy continuum and annihilation line are gone, low-energy Compton-scattered photons can still be detected with an almost unchanged flux. 23 references

Sources of gamma radiation in a reactor core

Energy Technology Data Exchange (ETDEWEB)

Roos, Matts

1959-05-15

In a thermal reactor the gamma ray sources of importance for shielding calculations and related aspects are 1) fission, 2) decay of fission products, 3) capture processes in fuel, poison and other materials, 4) inelastic scattering in the fuel and 5) decay of capture products. The energy release and the gamma ray spectra of these sources have been compiled or estimated from the latest information available, and the results are presented in a general way to permit application to any thermal reactor, fueled with a mixture of {sup 235}U and {sup 238}U. As an example the total spectrum and the spectrum of radiation escaping from a fuel rod in the Swedish R3-reactor are presented.

Gamma response study of radiation sensitive MOSFETs for their use as gamma radiation sensor

Energy Technology Data Exchange (ETDEWEB)

Srivastava, Saurabh; Kumar, A. Vinod [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai (India); Aggarwal, Bharti; Singh, Arvind; Topkar, Anita, E-mail: anita@barc.gov.in [Electronics Division, Bhabha Atomic Research Centre, Mumbai (India)

2016-05-23

Continuous monitoring of gamma dose is important in various fields like radiation therapy, space-related research, nuclear energy programs and high energy physics experiment facilities. The present work is focused on utilization of radiation-sensitive Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) to monitor gamma radiation doses. Static characterization of these detectors was performed to check their expected current-voltage relationship. Threshold voltage and transconductance per unit gate to source voltage (K factor) were calculated from the experimental data. The detector was exposed to gamma radiation in both, with and without gate bias voltage conditions, and change in threshold voltage was monitored at different gamma doses. The experimental data was fitted to obtain equation for dependence of threshold voltage on gamma dose. More than ten times increase in sensitivity was observed in biased condition (+3 V) compared to the unbiased case.

Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

Energy Technology Data Exchange (ETDEWEB)

Scott Wilde, Raymond Keegan

2008-07-01

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

Spatial and energy distributions of skyshine neutron and gamma radiation from nuclear reactors on the ground-air boundary

Energy Technology Data Exchange (ETDEWEB)

Orlov, Y.; Netecha, M.E.; Vasiliev, A.P.; Avaev, V.N.; Vasiliev, G.A. [Research and Development Institute of Power Engineering, Moscow (Russian Federation); Zelensky, D.I.; Istomin, Y.L.; Cherepnin, Y.S. [Institute of Atomic Energy of the National Nuclear Center of the Republic of Kazakhstan, Semipalatinsk-21 (Kazakhstan); Nomura, Y. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2000-03-01

A set of measurements on skyshine radiation was conducted at two special research reactors. A broad range of detectors was used in the measurements to record neutron and gamma radiations. Dosimetric and radiometric field measurements of the neutrons and gamma quanta of the radiation scattered in the air were performed at distances of 50 to 1000 m from the reactor during different weather conditions. The neutron spectra in the energy range of 1 eV to 10 MeV and the gamma quanta spectra in the range of 0.1-10 MeV were measured. (author)

Effect of scatter media on small gamma camera imaging characteristics

International Nuclear Information System (INIS)

Ser, H. K.; Choi, Y.; Yim, K. C.

2001-01-01

Effect of scatter media materials and thickness, located between radioactivity and small gamma camera, on imaging characteristics was evaluated. The small gamma camera developed for breast imaging was consisted of collimator, NaI(TI) crystal (60x60x6 mm 3 ). PSPMT (position sensitive photomultiplier tube), NIMs and personal computer. Monte Carlo simulation was performed to evaluate the system sensitivity with different scatter media thickness (0∼8 cm) and materials (air and acrylie) with parallel hole collimator and diverging collimator. The sensitivity and spatial resolution was measured using the small gamma camera with the same condition applied to the simulation. Counts was decreased by 10% (air) and 54% (acrylic) with the parallel hole collimator and by 35% (air) and 63% (acrylic) with the diverging collimator. Spatial resolution was decreased as increasing the thickness of scatter media. This study substantiate the importance of a gamma camera positioning and the minimization of the distance between detector and target lesion in the clinical application of a gamma camera

Tomographic imaging of matter using primary and secondary X-and gamma-radiation

International Nuclear Information System (INIS)

Holloway, I.E.

1991-04-01

Gamma rays may interact with matter by a variety of processes, many of which give rise to secondary radiations. This thesis examines the possibility of performing tomographic imaging by means of these secondary photons using low-cost apparatus. The techniques are compared with each other and with transmission tomography, which plays such an important role in modern diagnostic imaging. The progress of industrial tomography is reviewed as are techniques of investigation using gamma ray scattering in both industry and medicine. Some new applications of a simple gamma ray computerized tomography (CT) scanner have been performed. A method of determining the spatial distribution of pure beta emitters in matter by performing tomographic imaging using the bremsstrahlung radiation produced by the beta particles has been demonstrated. This technique has been shown to permit imaging at depths in material greatly exceeding the range of beta particles in matter. All the imaging techniques using secondary radiation have displayed two principal limitations: long scanning times and poor quantitative accuracy. The low scanning rate results from the small number of secondary photons that are detected. The major contributing factors to poor accuracy are attenuation and the noise produced by unwanted in-scattering. The possible applications for secondary photon imaging have been briefly outlined and some suggestions for future work are included. Although techniques based upon imaging using secondary radiation will not be able to compete with transmission CT in the vast majority of applications, they may prove valuable in a range of specialised fields. (author)

Scatter Dose in Patients in Radiation Therapy

International Nuclear Information System (INIS)

Schmidt, W. F. O.

2003-01-01

Patients undergoing radiation therapy are often treated with high energy radiation (bremsstrahlung) which causes scatter doses in the patients from various sources as photon scatter coming from collimator, gantry, patient, patient table or room (walls, floor, air) or particle doses resulting from gamma-particle reactions in the atomic nucleus if the photon energies are above 8 MeV. In the last years new treatment techniques like IMRT (esp the step-and-shoot- or the MIMIC-techniques) have increased interest in these topics again. In the lecture an overview about recent measurements on scatter doses resulting from gantry, table and room shall be given. Scatter doses resulting from the volume treated in the patient to other critical parts of the body like eyes, ovarii etc. have been measured in two diploma works in our institute and are compared with a program (PERIDOSE; van der Giessen, Netherlands) to estimate them. In some cases these scatter doses have led to changes of treatment modalities. Also an overview and estimation of doses resulting from photon-particle interactions is given according to a publication from Gudowska et al.(Gudowska I, Brahme A, Andreo P, Gudowski W, Kierkegaard J. Calculation of absorbed dose and biological effectiveness from photonuclear reactions in a bremsstrahlung beam of end point 50 MeV. Phys Med Biol 1999; 44(9):2099-2125.). Energy dose has been calculated with Monte Carlo-methods and is compared with analytical methods for 50 MV bremsstrahlung. From these data biologically effective doses from particles in different depths of the body can be estimated also for energies used in normal radiotherapy. (author)

[Gamma scattering in condensed matter with high intensity Moessbauer radiation

International Nuclear Information System (INIS)

1989-01-01

There are four areas where major progress has occurred this year. We have applied the Fourier-transform method of describing and analyzing Moessbauer effect (ME) line shapes to make measurements of the temperature dependence of the recoilless fraction in tungsten. We have carried out quasi-elastic measurements of the gamma scattering from viscous liquids, learning about diffusive motion in polydimethylsiloxane, pentadecane, and glycerol. We have made major progress in fundamental physics, having shown for the first time how to determine precise quantum interference parameters, obtaining experimental results on the 46.5 keV line of 183 W and the 129 keV line of 191 Ir. Finally, we have continued our development of MICE detectors, with a theoretical analysis of the MICE lineshape and its relation to the lineshape of conventional transmission ME spectroscopy. 12 refs

Radiative corrections to the beam spin asymmetry in photon electroproduction e polarized p {yields} ep{gamma}

Energy Technology Data Exchange (ETDEWEB)

Fonvieille, H.; Bensafa, I. [LPC-Clermont-Fd, Universite Blaise Pascal, F-63170 Aubiere Cedex (France)

2006-11-15

We have measured at MAMI the beam single spin asymmetry (SSA) in exclusive photon electroproduction (e polarized p {yields} ep{gamma}) with a longitudinally polarized beam, in the region of the {delta}(1232) resonance. In this document the value of the radiative correction to this asymmetry is obtained for our kinematics. Although the correction is expected to be very small and negligible, its value is needed as a confirmation and for the purpose of systematic error estimate. The parameter of kinematics are given as follows: four-momentum transfer of the virtual photon, Q{sup 2} = 0.35 GeV{sup 2}; total energy in the ({gamma}p) center of mass, W=1.190 GeV; polarization of the virtual photon, {epsilon}=0.48; azimuthal angle (lepton-hadron planes), {phi} = 220 angle; polar angle of Compton scattering in center of mass, {theta}{sub {gamma}}{sub {gamma}} in [0 angle, 40 angle]; incoming electron beam energy, E{sub e} = 0.88 GeV; scattered electron energy, E{sub 0}' = 0.40 GeV; polar angle of scattered electron {theta}{sub e} = 59.9 angle. The radiative correction is calculated by the radcorr code written by M. Vanderhaeghen, in a version adapted to beam spin asymmetries.In practice, the conclusions are twofold: - the asymmetry that was measured in the VCS channel does not need to be corrected for radiative effects, given the large statistical error bar attached to the experimental values (an asymmetry of 1-10 % with a statistical error bar of 3-4 %); - a systematic error {delta}SSA{sub syst} on the asymmetry will be considered, related to uncertainties in the calculation of the radiative correction (at least two of them have been mentioned here: the cross section model and the soft photon limit). To estimate this error a 100 % variation of the radiative correction was assumed. For the radiative correction itself the maximal value found was taken. Therefore one can take: {delta}SSA{sub syst} = {+-}2.7 x 10{sup -3}.

Location of alien bodies in a media according to the data of scattering gamma radiation

International Nuclear Information System (INIS)

Vasil'ev, M.B.; Chuvashov, N.F.; Skuchaev, Yu.K.; Markov, V.I.

1995-01-01

Locations of alien bodies in a medium are studied by the method of model experiment using scattering γ-radiation. 60 Co and 137 Cs were used as radiation sources. The scattering bodies were made in the form of aluminium, iron and lead cylinders of different diameters inserted inside hollow cylindrical water, aluminium and iron media. The cases are reviewed when the alien bodies are in the center of cylindrical media. The obtained data are presented in the graphical form and in the form of tables. 4 refs., 4 figs. 1 tab

Transition radiation and transition scattering

International Nuclear Information System (INIS)

Ginzburg, V.L.

1982-01-01

Transition radiation is a process of a rather general character. It occurs when some source, which does not have a proper frequency (for example, a charge) moves at a constant velocity in an inhomogeneous and (or) nonstationary medium or near such a medium. The simplest type of transition radiation takes place when a charge crosses a boundary between two media (the role of one of the media may be played by vacuum). In the case of periodic variation of the medium, transition radiation possesses some specific features (resonance transition radiation or transition scattering). Transition scattering occurs, in particular, when a permittivity wave falls onto an nonmoving (fixed) charge. Transition scattering is closely connected with transition bremsstrahlung radiation. All these transition processes are essential for plasma physics. Transition radiation and transition scattering have analogues outside the framework of electrodynamics (like in the case of Vavilov-Cherenkov radiation). In the present report the corresponding range of phenomena is elucidated, as far as possible, in a generally physical aspect. (Auth.)

Attenuation of Reactor Gamma Radiation and Fast Neutrons Through Large Single-Crystal Materials

International Nuclear Information System (INIS)

Adib, M.

2009-01-01

A generalized formula is given which, for neutron energies in the range 10-4< E< 10 eV and gamma rays with average energy 2 MeV , permits calculation of the transmission properties of several single crystal materials important for neutron scattering instrumentation. A computer program Filter was developed which permits the calculation of attenuation of gamma radiation, nuclear capture, thermal diffuse and Bragg-scattering cross-sections as a function of materials constants, temperature and neutron energy. The applicability of the deduced formula along with the code checked from the obtained agreement between the calculated and experimental neutron transmission through various single-crystals A feasibility study for use of Si, Ge, Pb, Bi and sapphire is detailed in terms of optimum crystal thickness, mosaic spread and cutting plane for efficient transmission of thermal reactor neutrons and for rejection of the accompanying fast neutrons and gamma rays.

Earth formation pulsed neutron porosity logging system utilizing epithermal neutron and inelastic scattering gamma ray detectors

International Nuclear Information System (INIS)

Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

1978-01-01

An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector and an inelastic scattering gamma ray detector is moved through a borehole. The detection of inelastic gamma rays provides a measure of the fast neutron population in the vicinity of the detector. repetitive bursts of neutrons irradiate the earth formation and, during the busts, inelastic gamma rays representative of the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. the fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

External exposure from gamma radiation in uranium mines

International Nuclear Information System (INIS)

Thomson, J.E.

1982-01-01

Radiation doses received by workers in a high ore grade uranium mine are compared to those of other radiation workers and the need to be able to calculate the exposure rate from an ore body is indicated. The uranium-238 decay chain is presented and particular reference is made to the main gamma emitters and secular equilibrium of the members of the chain. Difficulties in dealing with a self attenuating volume source, in which scattering is important, are pointed out and traditional methods of solution are mentioned. It is shown that in the special case of an infinite ore body a simple solution may be obtained using the energy conservation principle. A straightforward method for calculating the exposure rate from an arbitrarily shaped ore body is given and corrections due to air attenuation, different soil types and possible lack of secular equilibrium are dealt with. The gamma ray spectrum from the ore is discussed with specific reference to the selection of suitable exposure monitors and the calculation of transmission through shields

Cyclotron resonant scattering in the spectra of gamma-ray bursts

International Nuclear Information System (INIS)

Lamb, D.Q.; Wang, J.C.L.; Loredo, T.J.; Wasserman, I.; Fenimore, E.E.

1989-01-01

Data on the GB880205 gamma-ray bursts are presented that have implications for the nature of gamma-ray burst sources. It is shown that cyclotron resonant scattering and Raman scattering account well for the positions, strengths, and shapes of the relative strengths of the first and second harmonics and their narrow widths. These results imply the existence of a superstrong (B of about 2 x 10 to the 12th G) magnetic field in the vicinity of the X-ray emission region of GB880205. Such a superstrong magnetic field points to a strongly magnetic neutron star as the origin of gamma-ray bursts, and to the fact that the gamma-ray sources belong to the Galaxy. 59 refs

Experimental observation of energy dependence of saturation thickness of multiply scattered gamma photons

International Nuclear Information System (INIS)

Singh, Manpreet; Singh, Gurvinderjit; Singh, Bhajan; Sandhu, B.S.

2008-01-01

The gamma photons continue to soften in energy as the number of scatterings increases in the target having finite dimensions both in depth and lateral dimensions. The number of multiply scattered photons increases with an increase in target thickness, and saturates at a particular value of the target thickness known as saturation thickness (depth). The present measurements are carried out to study the energy dependence of saturation thickness of multiply scattered gamma photons from targets of various thicknesses. The scattered photons are detected by a properly shielded NaI(Tl) gamma ray detector placed at 90 deg. to the incident beam. We observe that the saturation thickness increases with increasing incident gamma photon energy. Monte Carlo calculations based upon the package developed by Bauer and Pattison [Compton scattering experiments at the HMI (1981), HMI-B 364, pp. 1-106] support the present experimental results

Design Study for Direction Variable Compton Scattering Gamma Ray

Science.gov (United States)

Kii, T.; Omer, M.; Negm, H.; Choi, Y. W.; Kinjo, R.; Yoshida, K.; Konstantin, T.; Kimura, N.; Ishida, K.; Imon, H.; Shibata, M.; Shimahashi, K.; Komai, T.; Okumura, K.; Zen, H.; Masuda, K.; Hori, T.; Ohgaki, H.

2013-03-01

A monochromatic gamma ray beam is attractive for isotope-specific material/medical imaging or non-destructive inspection. A laser Compton scattering (LCS) gamma ray source which is based on the backward Compton scattering of laser light on high-energy electrons can generate energy variable quasi-monochromatic gamma ray. Due to the principle of the LCS gamma ray, the direction of the gamma beam is limited to the direction of the high-energy electrons. Then the target object is placed on the beam axis, and is usually moved if spatial scanning is required. In this work, we proposed an electron beam transport system consisting of four bending magnets which can stick the collision point and control the electron beam direction, and a laser system consisting of a spheroidal mirror and a parabolic mirror which can also stick the collision point. Then the collision point can be placed on one focus of the spheroid. Thus gamma ray direction and collision angle between the electron beam and the laser beam can be easily controlled. As the results, travelling direction of the LCS gamma ray can be controlled under the limitation of the beam transport system, energy of the gamma ray can be controlled by controlling incident angle of the colliding beams, and energy spread can be controlled by changing the divergence of the laser beam.

A method for determination mass absorption coefficient of gamma rays by Compton scattering.

Science.gov (United States)

El Abd, A

2014-12-01

A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

A method for determination mass absorption coefficient of gamma rays by Compton scattering

International Nuclear Information System (INIS)

El Abd, A.

2014-01-01

A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed. - Highlights: • Compton scattering of γ−rays was used for determining mass absorption coefficient. • Scattered intensities were determined by the MCSHAPE software. • Mass absorption coefficients were determined for some compounds, mixtures and alloys. • Mass absorption coefficients were calculated by Winxcom software. • Good agreements were found between determined and calculated results

The use of gamma radiation in fluid flow measurements

International Nuclear Information System (INIS)

Tjugum, S.A.; Johansen, G.A.

2000-01-01

The use of gamma radiation in densitometry measurements is a well known principle. These measurements are often used in the oil industry where there is a need for finding the gas fraction of an oil/water/gas flow. The traditional gamma densitometer has a simple construction, where the measured parameter is the attenuation of a single gamma beam. High reliability, robustness and the clamp-on possibility are advantages that this type of instruments offer. More information can be found by studying how radiation is scattered and absorbed by matter. This information is needed in new multiphase flow meters. Problems to be solved in these instruments are how to find volume fractions of more than two components, how to handle different flow regimes in non-homogeneous flow, and how to do measurements independent of the salinity of the water. The new technology involves multi-energy, multi-mode and multi-sensor systems. At the University of Bergen the focus has been on how to do flow regime and salinity independent measurements by using multi-sensor and multi-mode systems. This paper gives an overview of the different techniques, and presents the latest results within this field of research at the University of Bergen. (author)

gamma. radiation of ionium

Energy Technology Data Exchange (ETDEWEB)

Curie, I

1948-12-08

Following the work of Ward (Proc Cambridge Phil Soc 35 322(1939)), the ..gamma..-radiation of ionium (from an IoTh preparation) was studied with the aid of Ta and W screens, and an aluminum counter. The screen measurements confirmed Ward's findings of two radiations, of 68 keV and of about 200 keV. The number of quanta per second of each radiation was determined with the counter, which has been calibrated on certain L lines of radium. The global quanta number of L lines of ionium was also determined. The results were as follows: 0.7 quanta ..gamma.. of 68 keV for 100 ..cap alpha..-particles; 0.2 quanta ..gamma.. of 200 keV for 100 ..cap alpha..-particles; 10 quanta L for 100 ..cap alpha..-particles. These data, which show an important internal conversion, agree with the findings of Teillac (Compt Rend 227 1227 (1948)), who investigated the ..beta..-radiation of ionium. It is the radiation 68 keV which is highly converted. On the other hand, these results do no agree with the data on the fine structure of ionium found by Rosenblum, Valadares, and Vial (Compt Rend 227 1088(1948)).

Project Marna Natural Gamma Radiation MAP

International Nuclear Information System (INIS)

Suarez, E.; Fernandez, J.A.

1997-01-01

The confusion created by the accident that occurred in one of the Chernobyl reactors in April of 1986 made the general public and governments aware of the need for improved monitoring of environmental radiation levels. The levels of total gamma radiation or total gamma exposure rate over large areas reached values as high as 400 micro Roentgen/hour (mu R/h) and at points exceeded 1000 mu R/h. It should be borne in mind that, depending on the type of geological formations, normal values range from 5 to 30 mu R/h. The IAEA recommended to all countries that natural gamma radiation maps be made available to evaluate the levels of natural gamma radiation and possible increases, and it also indicated its concern that information be standardized. In addition, it stressed the advisability of using data obtained from uranium prospecting. (Author)

Directional Stand-off Detection of Fast Neutrons and Gammas Using Angular Scattering Distributions

Energy Technology Data Exchange (ETDEWEB)

Vanier P. e.; Dioszegi, I.; Salwen, C.; Forman, L.

2009-10-25

We have investigated the response of a DoubleScatter Neutron Spectrometer (DSNS) for sources at long distances (gr than 200 meters). We find that an alternative method for analyzing double scatter data avoids some uncertainties introduced by amplitude measurements in plastic scintillators.Time of flight is used to discriminate between gamma and neutron events, and the kinematic distributions of scattering angles are assumed to apply. Non-relativistic neutrons are most likely to scatter at 45°, while gammas with energies greater than 2 MeV are most likely to be forward scattered. The distribution of scattering angles of fission neutrons arriving from a distant point source generates a 45° cone, which can be back-projected to give the source direction. At the same time, the distribution of Compton-scattered gammas has a maximum in the forward direction, and can be made narrower by selecting events that deposit minimal energy in the first scattering event. We have further determined that the shape of spontaneous fission neutron spectra at ranges gr than 110 m is still significantly different from thecosmic ray background.

SU-E-J-142: Prompt Gamma Emission Measurements From a Passively Scattered Proton Beam On Targets Containing 16O, 12C and 14N

Energy Technology Data Exchange (ETDEWEB)

Jeyasugiththan, J [Department of Physics, University of Cape Town, Cape Town (South Africa); Department of Clinical Oncology, Teaching Hospital, Jeffna (Sri Lanka); Peterson, S [Department of Physics, University of Cape Town, Cape Town (South Africa)

2015-06-15

Purpose: To measure the prompt gamma emission from the important elements found in tissue ({sup 16}O,{sup 12}C and {sup 14}N) in a clinical passive-scatter treatment environment. Methods: The targets (composed of water, Perspex, graphite and liquid nitrogen) were irradiated with a 200 MeV passive-scatter proton beam and the discrete prompt gamma energy spectra was detected by a high resolution 2′ × 2′ LaBr. detector. In order to reduce the high level of radiation produced by the beam line elements, the detector was surrounded by 10 cm of lead to attenuate the scattered gamma-rays entering the detector with an extra 5 cm thick layer of lead added along the beam direction. A 10 cm thick collimator with a 5 cm × 10 cm rectangular opening was also used. Results: The prompt gamma peaks at 6.13 MeV and 4.44 MeV were clearly identified as a Result of the inelastic nuclear reaction between the protons and the 16O atoms found in the water target. The 6.13 MeV peak was 5% higher than the peak at 4.44 MeV for the water target. The 4.44 MeV peak was the only identified emission in the prompt gamma energy spectra from the graphite target ({sup 12}C). The expected 2.313 MeV peak form the{sup 14}N (liquid nitrogen target) was identified, but the other expected {sup 14}N peaks could not be resolved. Conclusion: Prompt gamma measurements with a passive-scatter proton beam are possible, but the presence of a high amount of background radiation from the patient final collimator presents a challenge at the treatment isocenter. The prominent prompt gamma peaks at 6.13 MeV and 4.44 MeV were identified from the water, Perspex and graphite targets. The prompt gammas from the liquid nitrogen target were difficult to see, but may not be significant in the in-vivo verification process.

Gamma irradiators for radiation processing

International Nuclear Information System (INIS)

2006-01-01

Radiation technology is one of the most important fields which the IAEA supports and promotes, and has several programmes that facilitate its use in the developing Member States. In view of this mandate, this Booklet on 'Gamma Irradiators for Radiation Processing' is prepared which describes variety of gamma irradiators that can be used for radiation processing applications. It is intended to present description of general principles of design and operation of the gamma irradiators available currently for industrial use. It aims at providing information to industrial end users to familiarise them with the technology, with the hope that the information contained here would assist them in selecting the most optimum irradiator for their needs. Correct selection affects not only the ease of operation but also yields higher efficiency, and thus improved economy. The Booklet is also intended for promoting radiation processing in general to governments and general public

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

Directory of Open Access Journals (Sweden)

Ivanov Kirill E.

2008-01-01

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

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

International Nuclear Information System (INIS)

Ivanov, K. E.; Ponomaryev-Stepnoi, N. N.; Stepennov, B. S.; Teterin, Y. A.; Teterin, A. Y.; Kharitonov, V. V.

2008-01-01

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

Observation of galactic gamma radiation

International Nuclear Information System (INIS)

Paul, J.A.

1982-09-01

A complete and deep survey of the galactic high-energy gamma radiation is now available, thanks to the gamma-ray telescopes on board of the SAS-2 and COS-B spacecrafts. A comparison of the COS-B gamma-ray survey with a fully sampled CO survey together with an Hsub(I) survey is used to show that a simple model, in which uniformly distributed cosmic rays interact with the interstellar gas, can account for almost all the gamma-ray emission observed in the first galactic quadrant. At medium galactic latitudes, it is shown that a relationship exists between the gamma radiation and the interstellar absorption derived from galaxy counts. Therefore gamma rays from the local galactic environment can be used as a valuable probe of the content and structure of the local interstellar medium. The large scale features of the local interstellar gas are revealed, in particular wide concentrations of nearby molecular hydrogen. On a smaller scale, the detection of numerous localized gamma-ray sources focuses the attention on some particular phases of clusters of young and massive stars where diffuse processes of gamma-ray emission may also be at work

SGR-76 gamma radiation level indicator

International Nuclear Information System (INIS)

Chubinskij-Nadezhdin, I.V.

1978-01-01

The design of a gamma-radiation level indicator is described; the instrument is part of a mobile radiometric laboratory (MRL). The design of the instrument permits gamma-radiation dose rates recording at 0.2-200 R/hr, and signals on gamma-background levels. The instrument has two separate threshold levels of signalling actuation. The light signalling at the first level is precautionary, and the sound signalling at the second level indicates the necessity of taking a decision as to whether or not the MRL can remain in the gamma-radiation field. Halogenic counters operating in a current mode are used as detectors. The basic error in recording the dose rate amounts to +-25%. Overall dimensions of the instrument 150x280x100 mm; weight less than 2.5 kg

Radiation shielding analysis

International Nuclear Information System (INIS)

Moon, S.H.; Ha, C.W.; Kwon, S.K.; Lee, J.K.; Choi, H.S.

1982-01-01

The theoretical bases of radiation streaming analysis in power reactors, such as ducts or reactor cavity, have been investigated. Discrete ordinates-Monte Carlo or Monte Carlo-Monte Carlo coupling techniques are suggested for the streaming analysis of ducts or reactor cavity. Single albedo scattering approximation code (SINALB) has been developed for simple and quick estimation of gamma-ray ceiling scattering, where the ceiling is assumed to be semi-infinite medium. This code has been employed to calculate the gamma-ray ceiling scattering effects in the laboratory containing a Co-60 source. The SINALB is applicable to gamma-ray scattering, only where the ceiling is thicker than Σsup(-1) and the height is at least twice higher than the shield wall. This code can be used for the purpose of preliminary radiation shield design. The MORSE code has been improved to analyze the gamma-ray scattering problem with on approximation method in respect to the random walk and estimation processes. This improved MORSE code has been employed to the gamma-ray ceiling scattering problem. The results of the improved MORSE calculation are in good agreement with the SINALB and standard MORSE. (Author)

Scattered radiation from applicators in clinical electron beams

International Nuclear Information System (INIS)

Battum, L J van; Zee, W van der; Huizenga, H

2003-01-01

In radiotherapy with high-energy (4-25 MeV) electron beams, scattered radiation from the electron applicator influences the dose distribution in the patient. In most currently available treatment planning systems for radiotherapy this component is not explicitly included and handled only by a slight change of the intensity of the primary beam. The scattered radiation from an applicator changes with the field size and distance from the applicator. The amount of scattered radiation is dependent on the applicator design and on the formation of the electron beam in the treatment head. Electron applicators currently applied in most treatment machines are essentially a set of diaphragms, but still do produce scattered radiation. This paper investigates the present level of scattered dose from electron applicators, and as such provides an extensive set of measured data. The data provided could for instance serve as example input data or benchmark data for advanced treatment planning algorithms which employ a parametrized initial phase space to characterize the clinical electron beam. Central axis depth dose curves of the electron beams have been measured with and without applicators in place, for various applicator sizes and energies, for a Siemens Primus, a Varian 2300 C/D and an Elekta SLi accelerator. Scattered radiation generated by the applicator has been found by subtraction of the central axis depth dose curves, obtained with and without applicator. Scattered radiation from Siemens, Varian and Elekta electron applicators is still significant and cannot be neglected in advanced treatment planning. Scattered radiation at the surface of a water phantom can be as high as 12%. Scattered radiation decreases almost linearly with depth. Scattered radiation from Varian applicators shows clear dependence on beam energy. The Elekta applicators produce less scattered radiation than those of Varian and Siemens, but feature a higher effective angular variance. The scattered

Modification of genetic effects of gamma radiation by laser radiation

International Nuclear Information System (INIS)

Khotyljova, L.V.; Khokhlova, S.A.; Khokhlov, I.V.

1988-01-01

Full text: Mutants obtained by means of ionizing radiation and chemical mutagens often show low viability and productivity that makes their use in plant breeding difficult. Methods reducing the destructive mutagen action on important functions of plant organism and increasing quality and practical value of induced mutants would be interesting. We believe that one method for increasing efficiency of experimental mutagenesis in plants is the application of laser radiation as a modificator of genetic effects of ionizing radiation and chemical mutagens. Combined exposure of wheat seedlings to a gamma radiation dose of 2 kR and to laser radiation with the wave length of 632.8 nm (power density - 20 mVt/cm 2 , exposure - 30 min.) resulted in reducing the chromosomal aberration percentage from 30.5% in the gamma version to 16.3% in the combined treatment version. A radiosensibilizing effect was observed at additional exposure of gamma irradiated wheat seeds to laser light with the wave length of 441.6 nm where chromosomal aberration percentage increased from 22% in the gamma-irradiation version to 31% in the combined treatment version. By laser radiation it is also possible to normalize mitotic cell activity suppressed by gamma irradiation. Additional seedling irradiation with the light of helium-neon laser (632.8 nm) resulted in recovery of mitotic cell activity from 21% to 62% and increasing the average content of DNA per nucleus by 10%. The influence of only laser radiation on plant variability was also studied and it was shown that irradiation of wheat seeds and seedlings with pulsed and continuous laser light of visible spectrum resulted in phenotypically altered forms in M 2 . Their frequencies was dependent upon power density, dose and radiation wave length. Number of altered forms increased in going from long-wave to short-wave spectrum region. In comparing efficiency of different laser types of pulsed and continuous exposure (dose - 180 J/cm 2 ) 2% of altered

Gamma radiation shielding analysis of lead-flyash concretes

International Nuclear Information System (INIS)

Singh, Kanwaldeep; Singh, Sukhpal; Dhaliwal, A.S.; Singh, Gurmel

2015-01-01

Six samples of lead-flyash concrete were prepared with lead as an admixture and by varying flyash content – 0%, 20%, 30%, 40%, 50% and 60% (by weight) by replacing cement and keeping constant w/c ratio. Different gamma radiation interaction parameters used for radiation shielding design were computed theoretically and measured experimentally at 662 keV, 1173 keV and 1332 keV gamma radiation energy using narrow transmission geometry. The obtained results were compared with ordinary-flyash concretes. The radiation exposure rate of gamma radiation sources used was determined with and without lead-flyash concretes. - Highlights: • Concrete samples with lead as admixture were casted with flyash replacing 0%, 20%, 30%, 40%, 50% and 60% of cement content (by weight). • Gamma radiation shielding parameters of concretes for different gamma ray sources were measured. • The attenuation results of lead-flyash concretes were compared with the results of ordinary flyash concretes

Environmental Gamma Radiation Measurements in Baskil District

International Nuclear Information System (INIS)

Canbazoglu, C.

2008-01-01

In this study, we have determined environmental gamma radiation dose rate in Baskil district which has very high granite content in its geographical structure. Gamma radiation dose rate measurements were achieved by portable radiation monitoring equipment based on the energy range between 40 keV and 1.3 MeV. The measurements were performed on asphalt and soil surface level and also one meter above the ground surface. The gamma dose rate was also performed inside and outside of buildings over the district. The dose rates were found to be between 8.46μR/h and 34.66 μR/h. Indoor and outdoor effective dose rate of the gamma radiation exposure has been calculated to be 523μSv/y and 196μSv/y, respectively

Investigation of epigenetic gene regulation in Arabidopsis modulated by gamma radiation

International Nuclear Information System (INIS)

Woo, Hye Ryun; Kim, Jae Sung; Lee, Myung Jin; Lee, Dong Joon; Kim, Young Min; Jung, Joon Yong; Han, Wan Keun; Kang, Soo Jin

2011-12-01

To investigate epigenetic gene regulation in Arabidopsis modulated by gamma radiation, we examined the changes in DNA methylation and histone modification after gamma radiation and investigated the effects of gamma radiation on epigenetic information and gene expression. We have selected 14 genes with changes in DNA methylation by gamma radiation, analyzed the changes of histone modification in the selected genes to reveal the relationship between DNA methylation and histone modification by gamma radiation. We have also analyzed the effects of gamma radiation on gene expression to investigate the relationship between epigenetic information and gene expression by gamma radiation. The results will be useful to reveal the effects of gamma radiation on DNA methylation, histone modification and gene expression. We anticipate that the information generated in this proposal will help to find out the mechanism underlying the changes in epigenetic information by gamma radiation

Environmental gamma radiation monitoring at Visakhapatnam using thermoluminescence dosimeters

International Nuclear Information System (INIS)

Swarnkar, M.; Sahu, S.K.; Takale, R.A.; Shetty, P.G.; Pundit, G.G.; Puranik, V.D.

2012-01-01

The gamma rays are the most significant part of environmental dose due to its large range and deep penetrating power. The environmental gamma radiation is mainly originated from two sources natural radiation and artificially produced radiation. The natural radiation dose arises from the cosmic radiation (galactic and solar) and from the Earth (terrestrial) surface. In the last few decades there is a growing concern all over the world about radiation and their exposure to population. Thus it is necessary to conduct radiological environmental surveillance. The radiation survey data are useful to establish the natural background gamma radiation levels. Extensive gamma radiation survey was carried out around the surroundings of Vishakhapatnam using Thermoluminescence Dosimeters (TLDs). The CaSO 4 :(0.2 mole %) Dy Teflon TLD discs, specifically designed for environmental gamma radiation monitoring purpose were used. These TLD badge are having very high TL sensitivity, a negligible fading rate and a stable TL response. TLDs were deployed on quarterly basis for two years to obtain the cumulative gamma background radiation levels in the study area. The radiological survey was also carried out by using a calibrated radiation survey meter. The annual dose rates were computed from quarterly values actually found and normalised to 365 days. The environmental gamma radiation levels around Vishakhapatnam were found to be in the range of 0.79 mGy/y to 1.86 mGy/y. It is clearly seen from the results that location to location there is a large variation in external gamma radiation levels. During the cycle of the TLD survey, spot readings of the background radiation levels were taken, both while placing the TLDs and while removing them. The instantaneous dose rates measured using survey meter, are also following the large variation as found in TLDs. It varies between 110 nGy/hr to 210 nGy/hr. (author)

Characterization of hydrothermal green quartz produced by gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Enokihara, Cyro T.; Rela, Paulo R., E-mail: cteiti@ipen.br, E-mail: prela06@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Schultz-Güttler, Rainer A., E-mail: rainersgut@gmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Geociencias

2015-07-01

A specific variety of quartz showing a green color in nature or induced artificially by radiation gamma ({sup 60}Co) is quite rare. Only two occurrences are known today, where this type of quartz can be found: Canada, at the Thunder Bay Amethyst Mine, Ontario and Brazil, at widely scattered geode occurrences along a 600 km stretch from Quarai at Brazils southern most tip to Uberlandia in Minas Gerais. These two occurrences have been formed by strong hydrothermal activities.That way much quartz crystals showed a very fast growth history facilitating the formation of growth defects (twinning, small angle tilting, mosaic growth, striations) and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work the material analyzed is from hydrothermal regimes found in intrusions of basaltic rocks located in the Rio Grande do Sul state. To characterize these materials, colored green by gamma rays, analyses by ICP, electron microscopy, water loss techniques and UV-VIS or NIR-FTIR spectroscopic measurements have been made. Silanol complexes are formed, which by radiation due to gamma rays form the color center NBOHC (Non-bonding Oxygen Hole Center), showing absorption between 590 to 620 nm, responsible for the green color. The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li). There is no correlation between water content and cations as in other color varieties. (author)

Mathematical simulation of gamma-radiation angle distribution measurements

International Nuclear Information System (INIS)

Batij, V.G.; Batij, E.V.; Egorov, V.V.; Fedorchenko, D.V.; Kochnev, N.A.

2008-01-01

We developed mathematical model of the facility for gamma-radiation angle distribution measurement and calculated response functions for gamma-radiation intensities. We developed special software for experimental data processing, the 'Shelter' object radiation spectra unfolding and Sphere detector (ShD) angle resolution estimation. Neuronet method using for detection of the radiation directions is given. We developed software based on the neuronet algorithm, that allows obtaining reliable distribution of gamma-sources that make impact on the facility detectors at the measurement point. 10 refs.; 15 figs.; 4 tab

Sterilization plants equipped with the isotopic gamma radiation sources

International Nuclear Information System (INIS)

Mehta, K.; Chmielewski, A.G.

2007-01-01

Presentation describes different isotopic gamma radiation sources applicable for sterilization of food and medical materials. Certain gamma pallet irradiators, mini gamma irradiators and different scale gamma tote irradiators are presented. It is concluded, that about two hundreds plants with gamma radiation sources operates in different countries. However, industrially developed countries must construct much more plants than operates now

Development of radiation safety monitoring system at gamma greenhouse gamma facility

International Nuclear Information System (INIS)

Hairul Nizam Idris; Azimawati Ahmad, Ahmad Zaki Hussain; Ahmad Fairuz Mohd Nasir

2009-01-01

This paper is discussing about installation of radiation safety monitoring system at Gamma Greenhouse Gamma facility, Agrotechnology and Bioscience Division (BAB). This facility actually is an outdoor type irradiation facility, which first in Nuclear Malaysia and the only one in Malaysia. Source Cs-137 (801 Curie) was use as radiation source and it located at the centre of 30 metres diameter size of open irradiation area. The radiation measurement and monitoring system to be equipped in this facility were required the proper equipment and devices, specially purpose for application at outside of building. Research review, literature study and discussion with the equipment manufacturers was being carried out, in effort to identify the best system should be developed. Factors such as tropical climate, environment surrounding and security were considered during selecting the proper system. Since this facility involving with panoramic radiation type, several critical and strategic locations have been fixed with radiation detectors, up to the distance at 200 meter from the radiation source. Apart from that, this developed system also was built for capable to provide the online real-time reading (using internet). In general, it can be summarized that the radiation safety monitoring system for outdoor type irradiation facility was found much different and complex compared to the system for indoor type facility. Keyword: radiation monitoring, radiation safety, Gamma Greenhouse, outdoor irradiation facility, panoramic radiation. (Author)

Effects of gamma radiation in soybean

International Nuclear Information System (INIS)

Franco, Jose Gilmar; Franco, Suely Salumita Haddad; Arthur, Valter; Arthur, Paula Bergamin; Franco, Caio Haddad

2015-01-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Soya dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.245 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. Five treatments radiation doses were applied as follows: 0 (control); 25; 50; 75 and 100 Gy. Seed germination and harvest of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were doses of 25, 50 and 75 Gy. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Effects of gamma radiation in soybean

Energy Technology Data Exchange (ETDEWEB)

Franco, Jose Gilmar; Franco, Suely Salumita Haddad; Arthur, Valter; Arthur, Paula Bergamin, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio Haddad [Centro Nacional de Pesquisa em Energia e Materiais (LNBio/CNPEM), Campinas, SP (Brazil). Laboratorio Nacional de Biociencias; Villavicencio, Anna Lucia, E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Soya dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.245 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. Five treatments radiation doses were applied as follows: 0 (control); 25; 50; 75 and 100 Gy. Seed germination and harvest of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were doses of 25, 50 and 75 Gy. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Study of the gamma radiation of ionium

Energy Technology Data Exchange (ETDEWEB)

Curie, I

1949-12-01

A Geiger counter study has been made of the ..gamma.. radiation of ionium. Eleven quanta of the L radiation of radium were observed for every hundred ..cap alpha.. disintegrations, and three ..gamma.. rays were found with energies of 68, 140, and 240 keV at a rate of 0.85, 0.33, 0.05 quanta, respectively, for 100 disintegrations. It is noted that the radiation spectrum of ionium as a whole is difficult to interpret. In the course of this work, the author calculated the efficiency of a thin-walled aluminum counter, both for the L radiation of radium and for ..gamma.. rays of 68 keV. The author also measured, for soft radiation, the ratio between the efficiency of a thin-walled aluminum counter and that of a similar counter lined with 0.11 mm of lead.

Cosmic gamma-ray background radiation. Current understandings and problems

International Nuclear Information System (INIS)

Inoue, Yoshiyuki

2015-01-01

The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space telescope has recently measured it at 0.1-820 GeV and revealed that the cosmic GeV gamma-ray background is composed of blazars, radio galaxies, and star-forming galaxies. However, Fermi still leaves the following questions. Those are dark matter contribution, origins of the cosmic MeV gamma-ray background, and the connection to the IceCube TeV-PeV neutrino events. In this proceeding, I will review the current understandings of the cosmic gamma-ray background and discuss future prospects of cosmic gamma-ray background radiation studies. (author)

Time-domain, nuclear-resonant, forward scattering: the classical approach

International Nuclear Information System (INIS)

Hoy, G.R.

1997-01-01

This paper deals with the interaction of electromagnetic radiation with matter assuming the matter to have nuclear transitions in resonance with incident electromagnetic radiation. The source of the radiation is taken to be of two types; natural radioactive gamma decay and synchrotron radiation. Numerical examples using 57 Fe are given for the two types of source radiation. Calculated results are contrasted for the two cases. Electromagnetic radiation produced by recoil-free gamma-ray emission has essentially the natural linewidth. Electromagnetic radiation from a synchrotron, even with the best monochromators available, has a relatively broad-band spectrum, essentially constant for these considerations. Polarization effects are considered. In general, the nuclear-resonant medium changes the polarization of the input radiation on traversing the medium. Calculations are presented to illustrate that synchrotron radiation studies using nuclear-resonant forward scattering have the potential for making high-precision measurements of hyperfine fields and recoilless fractions. An interesting aspect of nuclear-resonant forward scattering, relative to possible gamma-ray laser development, is the so-called 'speed-up' effect

Gamma holography from multiple scattering

International Nuclear Information System (INIS)

Coussement, R.

2007-01-01

Since the introduction of heterodyne methods for synchrotron radiation (Cousesement et al. in Phys. Rev. B 54:16003, 1996; Callens et al. in Phys. Rev. 67:104423, 2003) one observes interferences between two scattering amplitudes; the scattering amplitude of resonant nuclei in a reference sample and the scattering amplitude of nuclei in the sample under investigation. Theses interferences can easily been observed as resonances in velocity spectra when one uses a time integrated method. They can also been observed as quantum beats, when one would use the time differential method. For both methods it is important that one uses a reference sample and therefore both methods disserved the name 'heterodyne methods.' As theses interferences are a product of two scattering amplitudes, the amplitude of a wave scattered form the investigated sample can be known with its phase. But it is assumed that the reference wave is known in advance by a proper choice of the reference sample. At first sight it is very likely that multiple scattering would add more complexity but in this paper it is claimed that on the contrary it provide a bonus, especially for single crystals. It provokes only a line broadening and a line shift of the resonances in the velocity spectra (or a change in the damping and frequency of the quantum beats when the time spectra are registered). Moreover these changes in the line shapes can easily be measured and they provide all the information needed to reconstruct a 3-D picture of the atomic arrangement of resonant nuclei and moreover they distinguish between different hyperfine sites. The method may be more practical for measurements on synchrotron radiation but it does also apply to velocity spectra obtained from resonant scattering with strong sources. The use of radioactive sources suffer from the disadvantage of poorer statistics or much longer accumulation times but they enjoy the advantage to be table-top and at-home experiments. As strong sources are

Kernel integration scatter model for parallel beam gamma camera and SPECT point source response

International Nuclear Information System (INIS)

Marinkovic, P.M.

2001-01-01

Scatter correction is a prerequisite for quantitative single photon emission computed tomography (SPECT). In this paper a kernel integration scatter Scatter correction is a prerequisite for quantitative SPECT. In this paper a kernel integration scatter model for parallel beam gamma camera and SPECT point source response based on Klein-Nishina formula is proposed. This method models primary photon distribution as well as first Compton scattering. It also includes a correction for multiple scattering by applying a point isotropic single medium buildup factor for the path segment between the point of scatter an the point of detection. Gamma ray attenuation in the object of imaging, based on known μ-map distribution, is considered too. Intrinsic spatial resolution of the camera is approximated by a simple Gaussian function. Collimator is modeled simply using acceptance angles derived from the physical dimensions of the collimator. Any gamma rays satisfying this angle were passed through the collimator to the crystal. Septal penetration and scatter in the collimator were not included in the model. The method was validated by comparison with Monte Carlo MCNP-4a numerical phantom simulation and excellent results were obtained. The physical phantom experiments, to confirm this method, are planed to be done. (author)

Measuring scatter radiation in diagnostic x rays for radiation protection purposes

International Nuclear Information System (INIS)

Panayiotakis, George; Vlachos, Ioannis; Delis, Harry; Tsantilas, Xenophon; Kalyvas, Nektarios; Kandarakis, Ioannis

2015-01-01

During the last decades, radiation protection and dosimetry in medical X-ray imaging practice has been extensively studied. The purpose of this study was to measure secondary radiation in a conventional radiographic room, in terms of ambient dose rate equivalent H*(10) and its dependence on the radiographic exposure parameters such as X-ray tube voltage, tube current and distance. With some exceptions, the results indicated that the scattered radiation was uniform in the space around the water cylindrical phantom. The results also showed that the tube voltage and filtration affect the dose rate due to the scatter radiation. Finally, the scattered X-ray energy distribution was experimentally calculated. (authors)

The effect of gamma-radiation on bilirubin

International Nuclear Information System (INIS)

Iqbal, M.S.; Shad, M.A.; Akhtar, M.I.

2001-01-01

The effect of gamma-radiations on bilirubin, in vitro, has been studied. It was found that gamma-radiation causes oxidation of bilirubin to biliverdine as one of the products. The likely implication of this effect in transformation of bilirubin to excretable products, in vino, in case of jaundice is discussed. (author)

Scaling, scattering, and blackbody radiation in classical physics

International Nuclear Information System (INIS)

Boyer, Timothy H

2017-01-01

Here we discuss blackbody radiation within the context of classical theory. We note that nonrelativistic classical mechanics and relativistic classical electrodynamics have contrasting scaling symmetries which influence the scattering of radiation. Also, nonrelativistic mechanical systems can be accurately combined with relativistic electromagnetic radiation only provided the nonrelativistic mechanical systems are the low-velocity limits of fully relativistic systems. Application of the no-interaction theorem for relativistic systems limits the scattering mechanical systems for thermal radiation to relativistic classical electrodynamic systems, which involve the Coulomb potential. Whereas the naive use of nonrelativistic scatterers or nonrelativistic classical statistical mechanics leads to the Rayleigh–Jeans spectrum, the use of fully relativistic scatterers leads to the Planck spectrum for blackbody radiation within classical physics. (paper)

Dosimetry and Shielding of X and Gamma Radiation

International Nuclear Information System (INIS)

Oncescu, M.; Panaitescu, I.

1992-01-01

This book covers the following problems: 1. X and Gamma radiations, 2. Interaction of X-ray and gamma radiations with matter, 3. Interaction of electrons with matter, 4. Principles and basic concepts of dosimetry, 5. Ionization dosimetry, 6. Calorimetric chemical and photographic dosimetry, 7. Solid state dosimetry, 8. Computation of dosimetric quantities, 9. Dosimetry in radiation protection, 10. Shielding of X and gamma radiations. The authors, well-known Romanian experts in Radiation Physics and Engineering, gave an up-dated, complete and readable account of this subject matter. The analyses of physical principles and concepts, of materials and instruments and of computational methods and applications are all well balanced to meat the needs of a broad readership

Effects of gamma radiation in tomato seeds

International Nuclear Information System (INIS)

Wiendl, Toni A.; Wiendl, Fritz W.; Franco, Suely S.H.; Franco, Jose G.; Althur, Valter; Arthur, Paula B.

2013-01-01

Tomato dry seeds of the hybrid 'Gladiador' F1 were exposed to low doses of gamma radiation from Co-60 source at 0,509 kGy tax rate in order to study stimulation effects of radiation on germination and plant growth. Eight treatments radiation doses were applied as follows: 0 (control); 2,5; 5,0; 7,5; 10,0; 12,5; 15,0; 20,0 Gy. Seed germination as well as green fruits number, harvested fruit number, fruit weight and total production were assessed to identify occurrence of stimulation. Tomato seeds and plants were handled as for usual tomato production in Brazil. Low doses of gamma radiation treatment in the seeds stimulate germination and substantially increase fruit number and total production up to 86% at 10 Gy dose. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production thus, showing hormetic effects. (author)

Effects of gamma radiation in annatto seeds

Energy Technology Data Exchange (ETDEWEB)

Franco, Camilo F. de Oliveira, E-mail: camilo.urucum@hotmail.com [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA/EMEPA), Joao Pessoa, PB (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Harder, Marcia N.C., E-mail: marcia.harder@fatec.sp.gov.br [Centro Paula Souza, Curso Superior de Tecnologia em Bicombustiveis (FATEC), Piracicaba, SP (Brazil); Filho, Jose C.; Neto, Miguel B., E-mail: jorgecazefilho@yahoo.com.br [Empresa Estadual de Pesquisa Agropecuaria da Paraiba (EMEPA), Joao Pessoa, PB (Brazil)

2015-07-01

The annatto bixin has emerged as a major source of natural dyes used in the world notably by the substitution of synthetics harmful to human health and ecologic tendency in obtaining industrial products free of additives with applications in industries textiles; cosmetics; pharmaceutical and food mainly. The aim of this research was to obtain increased of germination rate and dormancy breaking on annatto seeds by gamma radiation. Annatto dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.456 kGy/hour dose rate. In order to study stimulation effects of radiation on germination rate and dormancy breaking in the seeds. Five treatments with gamma radiation doses were applied as follows: 0 (control); 100; 125; 150 and 175 Gy. After irradiation the annatto seeds were planted as for usual seed production. According to the results obtained in this experiment we can conclude that the low doses of gamma radiation utilized on the annatto seeds did not presented significantly effect on the germination of plants. But the best dose to increase the germination of seeds was 150 Gy. (author)

Effects of gamma radiation in annatto seeds

International Nuclear Information System (INIS)

Franco, Camilo F. de Oliveira; Arthur, Valter; Arthur, Paula B.; Harder, Marcia N.C.; Filho, Jose C.; Neto, Miguel B.

2015-01-01

The annatto bixin has emerged as a major source of natural dyes used in the world notably by the substitution of synthetics harmful to human health and ecologic tendency in obtaining industrial products free of additives with applications in industries textiles; cosmetics; pharmaceutical and food mainly. The aim of this research was to obtain increased of germination rate and dormancy breaking on annatto seeds by gamma radiation. Annatto dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.456 kGy/hour dose rate. In order to study stimulation effects of radiation on germination rate and dormancy breaking in the seeds. Five treatments with gamma radiation doses were applied as follows: 0 (control); 100; 125; 150 and 175 Gy. After irradiation the annatto seeds were planted as for usual seed production. According to the results obtained in this experiment we can conclude that the low doses of gamma radiation utilized on the annatto seeds did not presented significantly effect on the germination of plants. But the best dose to increase the germination of seeds was 150 Gy. (author)

Exposure of luminous marine bacteria to low-dose gamma-radiation.

Science.gov (United States)

Kudryasheva, N S; Petrova, A S; Dementyev, D V; Bondar, A A

2017-04-01

The study addresses biological effects of low-dose gamma-radiation. Radioactive 137 Cs-containing particles were used as model sources of gamma-radiation. Luminous marine bacterium Photobacterium phosphoreum was used as a bioassay with the bioluminescent intensity as the physiological parameter tested. To investigate the sensitivity of the bacteria to the low-dose gamma-radiation exposure (≤250 mGy), the irradiation conditions were varied as follows: bioluminescence intensity was measured at 5, 10, and 20°С for 175, 100, and 47 h, respectively, at different dose rates (up to 4100 μGy/h). There was no noticeable effect of gamma-radiation at 5 and 10°С, while the 20°С exposure revealed authentic bioluminescence inhibition. The 20°С results of gamma-radiation exposure were compared to those for low-dose alpha- and beta-radiation exposures studied previously under comparable experimental conditions. In contrast to ionizing radiation of alpha and beta types, gamma-emission did not initiate bacterial bioluminescence activation (adaptive response). As with alpha- and beta-radiation, gamma-emission did not demonstrate monotonic dose-effect dependencies; the bioluminescence inhibition efficiency was found to be related to the exposure time, while no dose rate dependence was found. The sequence analysis of 16S ribosomal RNA gene did not reveal a mutagenic effect of low-dose gamma radiation. The exposure time that caused 50% bioluminescence inhibition was suggested as a test parameter for radiotoxicity evaluation under conditions of chronic low-dose gamma irradiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gamma spectrometry and plastic-scintillator inherent background

International Nuclear Information System (INIS)

Pomerantsev, V.V.; Gagauz, I.B.; Mitsai, L.I.; Pilipenko, V.S.; Solomonov, V.M.; Chernikov, V.V.; Tsirlin, Y.A.

1988-01-01

The authors measured the energy resolution for a linear dependence of light yield on gamma radiation energy of gamma spectrometers based on plastic scintillation detectors for several plastic scintillators. If there were several gamma lines from the source the line with the highest energy was used to eliminate distortion due to overlap from the Compton background from gamma radiation of higher energy. Attenuation lengths were calculated. The tests were based on three modes of interaction between the gamma radiation and the scintillator: Compton scattering, the photoelectric effect, and pair formation. The contribution from light collection was also considered. The scintillators tested included polystyrene, polymethyl methacrylate, cesium iodide, and sodium iodide. Gamma sources included cesium 137, sodium 22, potassium 40, yttrium 88, thorium 232, and plutonium-beryllium

Characteristic Investigation of Unfolded Neutron Spectra with Different Priori Information and Gamma Radiation Interference

International Nuclear Information System (INIS)

Kim, Bong Hwan

2006-01-01

Neutron field spectrometry using multi spheres such as Bonner Spheres (BS) has been almost essential in radiation protection dosimetry for a long time at workplace in spite of poor energy resolution because it is not asking the fine energy resolution but requiring easy operation and measurement performance over a wide range of energy interested. KAERI has developed and used extended BS system based on a LiI(Eu) scintillator as the representative neutron spectrometry system for workplace monitoring as well as for the quantification of neutron calibration fields such as those recommended by ISO 8529. Major topics in using BS are how close the unfolded spectra is the real one and to minimize the interference of gamma radiation in neutron/gamma mixed fields in case of active instrument such as a BS with a LiI(Eu) scintillator. The former is related with choosing a priori information when unfolding the measured data and the latter is depend on how to discriminate it in intense gamma radiation fields. Influence of a priori information in unfolding and effect of counting loss due to pile-up of signals for the KAERI BS system were investigated analyzing the spectral measurement results of Scattered Neutron Calibration Fields (SNCF)

Measurement of the radiative decay width {gamma}[{lambda}(1520)->{lambda}{gamma}] with the SPHINX spectrometer

Energy Technology Data Exchange (ETDEWEB)

Antipov, Yu.M. [Institute for High Energy Physics, Protvino (Russian Federation); Artamonov, A.V. [Institute for High Energy Physics, Protvino (Russian Federation); Batarin, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Vavilov, D.V. [Institute for High Energy Physics, Protvino (Russian Federation); Victorov, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Eroshin, O.V. [Institute for High Energy Physics, Protvino (Russian Federation); Golovkin, S.V. [Institute for High Energy Physics, Protvino (Russian Federation); Gorin, Yu.P. [Institute for High Energy Physics, Protvino (Russian Federation); Kolganov, V.Z. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Kozhevnikov, A.P. [Institute for High Energy Physics, Protvino (Russian Federation); Konstantinov, A.S. [Institute for High Energy Physics, Protvino (Russian Federation); Kubarovsky, V.P. [Institute for High Energy Physics, Protvino (Russian Federation); Kurshetsov, V.F. [Institute for High Energy Physics, Protvino (Russian Federation); Landsberg, L.G. [Institute for High Energy Physics, Protvino (Russian Federation)]. E-mail: lgl@mx.ihep.su; Leontiev, V.M. [Institute for High Energy Physics, Protvino (Russian Federation); Lomkatsi, G.S. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Molchanov, V.V. [Institute for High Energy Physics, Protvino (Russian Federation)]. E-mail: molchanov@mx.ihep.su; Mukhin, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Nilov, A.F. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Patalakha, D.I. [Institute for High Energy Physics, Protvino (Russian Federation); Petrenko, S.V. [Institute for High Energy Physics, Protvino (Russian Federation); Smolyankin, V.T. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)

2004-12-16

The radiative decay {lambda}(1520)->{lambda}{gamma} was measured directly in the study of the exclusive diffractive-like reaction p+N->{lambda}(1520)K{sup +}+N, {lambda}(1520)->{lambda}{gamma} with the SPHINX spectrometer. The values of the branching and partial width of this radiative decay were obtained: BR[{lambda}(1520)->{lambda}{gamma}]=(1.02+/-0.21(stat)+/-0.15(syst))x10{sup -2} and {gamma}[{lambda}(1520)->{lambda}{gamma}]=159+/-33(stat)+/-26(syst)-bar keV.

Gamma Radiation from Fission Fragments

International Nuclear Information System (INIS)

Higbie, Jack

1969-10-01

The gamma radiation from the fragments of the thermal neutron fission of 235 U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10 -10 sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass

Gamma Radiation from Fission Fragments

Energy Technology Data Exchange (ETDEWEB)

Higbie, Jack

1969-10-15

The gamma radiation from the fragments of the thermal neutron fission of {sup 235}U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10{sup -10} sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass.

Some aspects of transition radiation and scattering theory

International Nuclear Information System (INIS)

Ginzburg, V.L.; Tsytovich, V.N.

1978-01-01

Some aspects of transition radiation and transition scattering theory are considered. The transition radiation in vacuum is analysed in the presence of a strong magnetic field. It is shown, that the constant electro-magnetic field makes vacuum similar to the uniaxial ferrodielectric. The appearance of the transition radiation in the nonstationary medium is discussed when its properties in the medium change abruptly in time. It is obtained, that both types of the transition radiation for nonrelativistic particles (on an abrupt boundary of the two media interface and under an abrupt change in time of the medium properties) differ quantitatively (on the order of the value). The role of the radiation transition and scattering in plasma physics has been elucidated from different points. Four most important features of these processes are pointed out. Particularly, essential is shown to be the type of the transition scattering when one plasma wave, being the dielectric constant wave transforms into another one also a plasma wave. In the processes of the transition scattering an essential part is played by the effects of the space dispersion, particularly when the scattering takes place on the small velocity particles. Finally besides transition scattering there exists in plasma or in some cases prevails a Thomson scattering. In this case an important role in plasma is played by the interference between the Thomson and the transition scattering

Effects of gamma radiation in tomato seeds

Energy Technology Data Exchange (ETDEWEB)

Wiendl, Toni A.; Wiendl, Fritz W.; Franco, Suely S.H.; Franco, Jose G.; Althur, Valter, E-mail: tawiendl@hotmail.com, E-mail: gilmita@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

2013-07-01

Tomato dry seeds of the hybrid 'Gladiador' F1 were exposed to low doses of gamma radiation from Co-60 source at 0,509 kGy tax rate in order to study stimulation effects of radiation on germination and plant growth. Eight treatments radiation doses were applied as follows: 0 (control); 2,5; 5,0; 7,5; 10,0; 12,5; 15,0; 20,0 Gy. Seed germination as well as green fruits number, harvested fruit number, fruit weight and total production were assessed to identify occurrence of stimulation. Tomato seeds and plants were handled as for usual tomato production in Brazil. Low doses of gamma radiation treatment in the seeds stimulate germination and substantially increase fruit number and total production up to 86% at 10 Gy dose. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production thus, showing hormetic effects. (author)

Induced Compton-scattering effects in radiation-transport approximations

International Nuclear Information System (INIS)

Gibson, D.R. Jr.

1982-02-01

The method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

Investigation of zones with increased ground surface gamma radiation

International Nuclear Information System (INIS)

Butkus, D.V.; Morkunas, G.S.; Styro, B.I.

1989-01-01

Measurements of the increased gamma radiation zones of soils were conducted in the South-Western part of the Litvinian. The shores of lakes in the north-eastern part of the Suduva high land were investigated. the maximum values of the gamma radiation dose rates were distributed along the lake shores at a distance of 1 m from the water surface, while farther than 1.5 m from it the dose rate was close to the natural value. The increased gamma radiation intensity zones on the ground surface were found only at the northern (Lake Reketija) or the western shore (other lakes under investigation). The highest values of the gamma radiation dose 200-600 μR/h (0.5-1.5 nGy/s) were observed in the comparatively small areas (up to several square metres). The gamma radiation intensity of soil surface increased strongly moving towards the point where the maximum intensity was obsered. 10 figs

Radiation breeding researches in gamma field. Results of researches

International Nuclear Information System (INIS)

Morishita, Toshikazu

2006-01-01

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

Scattered Radiation Emission Imaging: Principles and Applications

Directory of Open Access Journals (Sweden)

M. K. Nguyen

2011-01-01

Full Text Available Imaging processes built on the Compton scattering effect have been under continuing investigation since it was first suggested in the 50s. However, despite many innovative contributions, there are still formidable theoretical and technical challenges to overcome. In this paper, we review the state-of-the-art principles of the so-called scattered radiation emission imaging. Basically, it consists of using the cleverly collected scattered radiation from a radiating object to reconstruct its inner structure. Image formation is based on the mathematical concept of compounded conical projection. It entails a Radon transform defined on circular cone surfaces in order to express the scattered radiation flux density on a detecting pixel. We discuss in particular invertible cases of such conical Radon transforms which form a mathematical basis for image reconstruction methods. Numerical simulations performed in two and three space dimensions speak in favor of the viability of this imaging principle and its potential applications in various fields.

Study of radiation detectors response in standard X, gamma and beta radiation standard beams

International Nuclear Information System (INIS)

Nonato, Fernanda Beatrice Conceicao

2010-01-01

The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams ( 37 Cs and 60 Co), and some of them were tested in beta radiation ( 90 Sr+ 9' 0Y e 204 Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author)

Some factors affecting urokinase inactivation. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Iwata, Hiroo; Iketa, Yoshito

1985-10-01

The enzymatic activity of urokinase adsorbed on various polymer surfaces was measured to study the interaction between protein and polymers. The polymer films on which urokinase was adsorbed were exposed to either a high temperature or ..gamma..-radiation. The thermal inactivation rates were higher on hydrophobic polymers such as poly(ethylene terephthalate), nylon 6, and poly(vinylidene fluoride) than hydrophilic polymers like cellulose and ethylene-vinyl alcohol copolymer, indicating their substantial dependence on the interfacial free energy between the polymer and water. A similar dependence was also seen for the ..gamma..-radiation inactivation. Urokinase adsorbed on the hydrophobic polymers lost more easily its enzymatic activity by exposure to ..gamma..-radiation. The interfacial free energy seems to be one of the driving forces to denaturate proteins on polymers.

Induced Compton scattering effects in radiation transport approximations

International Nuclear Information System (INIS)

Gibson, D.R. Jr.

1982-01-01

In this thesis the method of characteristics is used to solve radiation transport problems with induced Compton scattering effects included. The methods used to date have only addressed problems in which either induced Compton scattering is ignored, or problems in which linear scattering is ignored. Also, problems which include both induced Compton scattering and spatial effects have not been considered previously. The introduction of induced scattering into the radiation transport equation results in a quadratic nonlinearity. Methods are developed to solve problems in which both linear and nonlinear Compton scattering are important. Solutions to scattering problems are found for a variety of initial photon energy distributions

THE ORIGIN OF GAMMA RAYS FROM GLOBULAR CLUSTERS

International Nuclear Information System (INIS)

Cheng, K. S.; Chernyshov, D. O.; Dogiel, V. A.; Hui, C. Y.; Kong, A. K. H.

2010-01-01

Fermi has detected gamma-ray emission from eight globular clusters (GCs). It is commonly believed that the energy sources of these gamma rays are millisecond pulsars (MSPs) inside GCs. Also it has been standard to explain the spectra of most Fermi Large Area Telescope pulsars including MSPs resulting from the curvature radiation (CR) of relativistic electrons/positrons inside the pulsar magnetosphere. Therefore, gamma rays from GCs are expected to be the collection of CR from all MSPs inside the clusters. However, the angular resolution is not high enough to pinpoint the nature of the emission. In this paper, we calculate the gamma rays produced by the inverse Compton (IC) scattering between relativistic electrons/positrons in the pulsar wind of MSPs in the GCs and background soft photons including cosmic microwave/relic photons, background star lights in the clusters, the galactic infrared photons, and the galactic star lights. We show that the gamma-ray spectrum from 47 Tucanae can be explained equally well by upward scattering of either the relic photons, the galactic infrared photons, or the galactic star lights, whereas the gamma-ray spectra from the other seven GCs are best fitted by the upward scattering of either the galactic infrared photons or the galactic star lights. We also find that the observed gamma-ray luminosity is correlated better with the combined factor of the encounter rate and the background soft photon energy density. Therefore, the IC scattering may also contribute to the observed gamma-ray emission from GCs detected by Fermi in addition to the standard CR process. Furthermore, we find that the emission region of high-energy photons from GCs produced by the IC scattering is substantially larger than the cores of GCs with a radius >10 pc. The diffuse radio and X-rays emitted from GCs can also be produced by the synchrotron radiation and IC scattering, respectively. We suggest that future observations including radio, X-rays, and gamma rays

Gamma radiation in ceramic capacitors: a study for space missions

Science.gov (United States)

dos Santos Ferreira, Eduardo; Sarango Souza, Juliana

2017-10-01

We studied the real time effects of the gamma radiation in ceramic capacitors, in order to evaluate the effects of cosmic radiation on these devices. Space missions have electronic circuits with various types of devices, many studies have been done on semiconductor devices exposed to gamma radiation, but almost no studies for passive components, in particular ceramic capacitors. Commercially sold ceramic capacitors were exposed to gamma radiation, and the capacitance was measured before and after exposure. The results clearly show that the capacitance decreases with exposure to gamma radiation. We confirmed this observation in a real time capacitance measurement, obtained using a data logging system developed by us using the open source Arduino platform.

Residual water treatment for gamma radiation

International Nuclear Information System (INIS)

Mendez, L.

1990-01-01

The treatment of residual water by means of gamma radiation for its use in agricultural irrigation is evaluated. Measurements of physical, chemical, biological and microbiological contamination indicators were performed. For that, samples from the treatment center of residual water of San Juan de Miraflores were irradiated up to a 52.5 kGy dose. The study concludes that gamma radiation is effective to remove parasites and bacteria, but not for removal of the organic and inorganic matter. (author). 15 refs., 3 tabs., 4 figs

Assembly of gamma radiation detection with directivity properties

International Nuclear Information System (INIS)

Stoica, M.; Talpalariu, C.

2016-01-01

An assembly of gamma radiation detection with directivity properties and small size enables the development of portable equipment or robots specialized in finding and signaling radioactively contaminated areas in case of nuclear incidents or decommissioning of nuclear installations. Directivity characteristic of the assembly of gamma radiation detection is very important when aiming to build an equipment for searching radioactively contaminated areas. In order to obtain a suitable directivity characteristics in terms of detection of gamma rays, it was necessary to construct a lead collimator with a cylindrical shape. The detector, preamplifier and amplifier pulse were placed inside the collimator and pulse discriminator circuit and power source were placed beside the collimator, all being disposed within the housing cylindrical experimental. A PIN photodiode type was used as a detector of gamma radiation. (authors)

Low doses of gamma radiation in soybean

International Nuclear Information System (INIS)

Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C.; Arthur, Valter; Arthur, Paula B.; Franco, Caio H.

2017-01-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Low doses of gamma radiation in soybean

Energy Technology Data Exchange (ETDEWEB)

Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C., E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio H. [Universidade Federal de São Paulo (UNIFESP), SP (Brazil). Departamento de Microbiologia, Imunologia e Parasitologia

2017-07-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Improving degradation of paracetamol by integrating gamma radiation and Fenton processes.

Science.gov (United States)

Cruz-González, Germán; Rivas-Ortiz, Iram B; González-Labrada, Katia; Rapado-Paneque, Manuel; Chávez-Ardanza, Armando; Nuevas-Paz, Lauro; Jáuregui-Haza, Ulises J

2016-10-14

Degradation of paracetamol (N-(4-hydroxiphenyl)acetamide) in aqueous solution by gamma radiation, gamma radiation/H2O2 and gamma radiation/Fenton processes was studied. Parameters affecting the radiolysis of paracetamol such as radiation dose, initial concentration of pollutant, pH and initial oxidant concentration were investigated. Gamma radiation was performed using a (60)Co source irradiator. Paracetamol degradation and mineralization increased with increasing absorbed radiation dose, but decreased with increasing initial concentration of the drug in aqueous solution. The addition of H2O2 resulted in an increased effect on irradiation-driven paracetamol degradation in comparison with the performance of the irradiation-driven process alone: paracetamol removal increased from 48.9% in the absence of H2O2 to 95.2% for H2O2 concentration of 41.7 mmol/L. However, the best results were obtained with gamma radiation/Fenton process with 100% of the drug removal at 5 kGy, for optimal H2O2 and Fe(2+) concentrations at 13.9 and 2.3 mmol/L, respectively, with a high mineralization of 63.7%. These results suggest gamma radiation/H2O2 and gamma radiation/Fenton processes as promising methods for paracetamol degradation in polluted wastewaters.

Polyvinyl Alcohol-Lead Nitrate Paint for Gamma Radiation Installations

International Nuclear Information System (INIS)

EI-Ahdal, M.A.

2007-01-01

Dealing with gamma ray installations represents an important problem for radiation protection workers. Radiation shielding is used to avoid the risk resulting from these gamma sources. This study suggested the use of polyvinyl alcohol (PVA) solution that contains lend nitrate (with lead metal/PVA= 1.72) to lower the gamma radiation intensity and reduce its risk to workers. This can be achieved by painting the radiation shielding with this solution Temperature relief of the irradiated solution shows the degradation of the polymer content up to 50 degree C, which starts to crosslink increasing the protection capability of this solution

Measurement of background gamma radiation in the northern Marshall Islands.

Science.gov (United States)

Bordner, Autumn S; Crosswell, Danielle A; Katz, Ainsley O; Shah, Jill T; Zhang, Catherine R; Nikolic-Hughes, Ivana; Hughes, Emlyn W; Ruderman, Malvin A

2016-06-21

We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of (137)Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered.

Effect of gamma radiation on graphite – PTFE dry lubrication system

International Nuclear Information System (INIS)

Singh, Sachin; Tyagi, Mukti; Seshadri, Geetha; Tyagi, Ajay Kumar; Varshney, Lalit

2017-01-01

An effect of gamma radiation on lubrication behavior of graphite -PTFE dry lubrication system has been studied using (TR-TW-30L) tribometer with thrust washer attachment in plane contact. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Gamma radiation exposure significantly improves the tribological properties indicated by decrease in coefficient of friction and wear properties of graphite -PTFE dry lubrication system. SEM and XRD analysis confirm the physico-chemical modification of graphite-PTFE on gamma radiation exposure leading to a novel dry lubrication system with good slip and anti friction properties. - Highlights: • Novel dry lubrication system of graphite -PTFE using gamma radiation. • Gamma radiation processing. • Reduction in coefficient of friction, frictional torque and wear loss of developed dry lubrication system.

Well logging with natural gamma radiation

International Nuclear Information System (INIS)

Ellis, D.V.

1983-01-01

An invention is described for use in natural gamma radiation well logging in which measurements taken in a borehole are used in the search for valuable underground resources such as oil or gas. The invention comprises deriving a log of natural gamma radiation detected in selected energy windows for a selected borehole depth interval and converting it into a log of the selected subsurface materials, e.g. Th, U, K. This log is corrected for the effects of 1) either a gamma ray emitter in the borehole fluid, e.g. potassium salts and/or 2) a gamma ray attenuator in the borehole fluid, e.g. a strong attenuator such as barite and/or hematite. The Th, U, K log is particularly useful in the exploration of oil and gas resources since the Th, U, K concentrations are a good indication as to the presence, type and volume of shale and clay in the formations surrounding the borehole. (U.K.)

Measuring element for the detection and determination of radiation doses of gamma radiation and neutrons

International Nuclear Information System (INIS)

Jahn, W.; Piesch, E.

1975-01-01

A measuring element detects and proves both gamma and neutron radiation. The element includes a photoluminescent material which stores gamma radiation and particles of arsenic and phosphorus embedded in the photoluminescent material for detecting neutron radiation. (U.S.)

Radiation scattering techniques

International Nuclear Information System (INIS)

Edmonds, E.A.

1986-01-01

Radiation backscattering techniques are useful when access to an item to be inspected is restricted to one side. These techniques are very sensitive to geometrical effects. Scattering processes and their application to the determination of voids, thickness measuring, well-logging and the use of x-ray fluorescence techniques are discussed. (U.K.)

The effect of Compton scattering on quantitative SPECT imaging

International Nuclear Information System (INIS)

Beck, J.W.; Jaszczak, R.J.; Starmer, C.F.

1982-01-01

A Monte Carlo code has been developed to simulate the response of a SPECT system. The accuracy of the code has been verified and has been used in this research to study and illustrate the effects of Compton scatter on quantitative SPECT measurements. The effects of Compton scattered radiation on gamma camera response have been discussed by several authors, and will be extended to rotating gamma camera SPECT systems. The unique feature of this research includes the pictorial illustration of the Compton scattered and the unscattered components of the photopeak data on SPECT imaging by simulating phantom studies with and without Compton scatter

Experimental observation of Z-dependence of saturation depth of 0.662 MeV multiply scattered gamma rays

International Nuclear Information System (INIS)

Singh, Gurvinderjit; Singh, Manpreet; Singh, Bhajan; Sandhu, B.S.

2006-01-01

The gamma photons continue to soften in energy as the number of scatterings increases in the sample having finite dimensions both in depth and lateral dimensions. The number of multiply scattered photons increases with an increase in target thickness and saturates at a particular value of the target thickness known as saturation depth. The present experiment is undertaken to study the effect of atomic number of the target on saturation depth of 0.662 MeV incident gamma photons multiply scattered from targets of various thicknesses. The scattered photons are detected by an HPGe gamma detector placed at 90 o to the incident beam direction. We observe that with an increase in target thickness, the number of multiply scattered photons also increases and saturates at a particular value of the target thickness. The saturation depth decreases with increasing atomic number. The double Compton scattered peak is also observed in the experimental spectra

GammaCam trademark radiation imaging system

International Nuclear Information System (INIS)

1998-02-01

GammaCam trademark, a gamma-ray imaging system manufactured by AIL System, Inc., would benefit a site that needs to locate radiation sources. It is capable of producing a two-dimensional image of a radiation field superimposed on a black and white visual image. Because the system can be positioned outside the radiologically controlled area, the radiation exposure to personnel is significantly reduced and extensive shielding is not required. This report covers the following topics: technology description; performance; technology applicability and alternatives; cost; regulatory and policy issues; and lessons learned. The demonstration of GammaCam trademark in December 1996 was part of the Large-Scale Demonstration Project (LSDP) whose objective is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) Chicago Pile-5 Research Reactor (CP-5). The purpose of the LSDP is to demonstrate that by using innovative and improved decontamination and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies

The determination of electron momentum densities by inelastic scattering gamma-ray-electron coincidence measurements: The (γ,eγ)-experiment

International Nuclear Information System (INIS)

Rollason, A.J.; Bell, F.; Schneider, J.R.

1989-09-01

Measurements have been made of the recoiling electron in 320 keV gamma ray inelastic scattering collisions in thin aluminium targets. The angular correlation of these electrons detected in coincidence with the scattered photon is in agreement with the kinematic requirements of the Compton effect and is correctly predicted by Monte Carlo simulations based on the impulse approximation. Further simulations of ideal-geometry experiments indicate that information about the initial electron momenta is available from an examination of those electron-photon events originating in a surface layer of one electronic mean free path depth and that elastic scattering of the recoil electrons from greater depths produces a nearly flat background to this signal. The results clearly demonstrate the feasibility of the (γ,eγ) experiment for studying electron momentum densities with synchrotron radiation. (orig.) With 23 refs., 17 figs

Angular distribution of 662keV multiply-Compton scattered gamma rays in copper

International Nuclear Information System (INIS)

Singh, Manpreet; Singh, Gurvinderjit; Sandhu, B.S.; Singh, Bhajan

2007-01-01

The angular distribution of multiple Compton scattering of 662keV gamma photons, obtained from six Curie 137 Cs source, incident on copper scatterer of varying thickness is studied experimentally in both the forward and backward hemispheres. The scattered photons are detected by a 51mmx51mm NaI(Tl) scintillation detector. The full-energy peak corresponding to singly scattered events is reconstructed analytically. We observe that the numbers of multiply scattered events, having same energy as in the singly scattered distribution, first increases with increase in target thickness and then saturate. The optimum thickness at which the multiply scattered events saturate is determined at different scattering angles

A study of effects of scattered reaction on physical parameters of a new gamma camera used in nuclear medicine

International Nuclear Information System (INIS)

Maury, Martine.

1979-01-01

This work is devoted to the analysis of the performance of a new gamma camera. This camera is characterized by the introduction of an image amplifier between the crystal detector and the localization system which compound four photomultipliers. The appreciation of performances of this new instrument is based on the measure of the physical parameters usually studied in this purpose: energy resolution, spatial resolution, modulation transfert fonction and contrast, sensitivity and deadtime. Furthermore, we have studied the influence of scattered radiation on the value of these parameters. Two studies complete this work: the artificial deterioration of the energy resolution of the camera inserting a noise, to estimate the importance of the energy resolution on the image contrast; the scanning of pulse amplitude spectra obtained from brain of patients in order to evaluate the participation of scattered radiation in the peak's constitution. We present, at last, a quality control programm for scintillation camera [fr

On the honeybee resistance to gamma radiation

International Nuclear Information System (INIS)

Courtois, G.; Lecomte, J.

1960-01-01

The honeybee, when irradiated by gamma radiations from a cobalt-60 source can stand a 18000 r dose without any apparent harm. Noticeable harm is observed for 90000 r. while immediate death of 100% of the individuals is obtained with a 200000 r dose. The physiological condition of the honeybee plays an important role in its resistance to gamma radiation. Reprint of a paper published in Annales de l'abeille, IV, 1959, p. 285-290 [fr

Effect of gamma radiation on graphite - PTFE dry lubrication system

Science.gov (United States)

Singh, Sachin; Tyagi, Mukti; Seshadri, Geetha; Tyagi, Ajay Kumar; Varshney, Lalit

2017-12-01

An effect of gamma radiation on lubrication behavior of graphite -PTFE dry lubrication system has been studied using (TR-TW-30L) tribometer with thrust washer attachment in plane contact. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Gamma radiation exposure significantly improves the tribological properties indicated by decrease in coefficient of friction and wear properties of graphite -PTFE dry lubrication system. SEM and XRD analysis confirm the physico-chemical modification of graphite-PTFE on gamma radiation exposure leading to a novel dry lubrication system with good slip and anti friction properties.

Stationary radiation of objects with scattering media

International Nuclear Information System (INIS)

Vasil'eva, Inna A

2001-01-01

The radiation observed inside or outside a stationary radiator with a scattering medium is a sum of components, each being determined by, first, the primary radiation from some part of the radiator and, second, the probability of this radiation reaching the region where it is observed. In this review, general and rather simple relations between these components are discussed. These relations, unlike the components themselves, are independent of the specific optical characteristics of the object as well as of its geometry, inhomogeneity, etc. In deriving the relations, the situations in which geometrical optics is either applicable or inapplicable to radiation in a scattering medium are considered. For the case where geometrical optics does apply, stationary relations are derived from the probabilistic stationarity condition for radiation passing through the medium, i.e., from the fact that all radiation emitted in a stationary regime disappears with probability unity. Equilibrium relations are derived from the stationary relations in the particular case of a thermal radiator in an isothermal cavity. To derive the stationary relations in the geometrical optics approximation, we obtain general solutions of the linear equation of transfer using the Green function approach. If geometrical optics cannot be applied to a scattering and radiating medium, only relations for the components of outgoing thermal radiation are obtained, and the generalized Kirchhoff law, obtained by Levin and Rytov using statistical radio-physics methods, is employed. In this case, stationary relations are also derived from a probabilistic stationarity condition; the equilibrium relations follow from the stationary ones as well as from the equilibrium condition for radiation in the isothermal cavity. The quantities involved in all the relations obtained are a subject of experimental and computational spectroscopic studies. Examples of current and potential applications are given. The relations

Scattering of Non-Relativistic Charged Particles by Electromagnetic Radiation

Science.gov (United States)

Apostol, M.

2017-11-01

The cross-section is computed for non-relativistic charged particles (like electrons and ions) scattered by electromagnetic radiation confined to a finite region (like the focal region of optical laser beams). The cross-section exhibits maxima at scattering angles given by the energy and momentum conservation in multi-photon absorption or emission processes. For convenience, a potential scattering is included and a comparison is made with the well-known Kroll-Watson scattering formula. The scattering process addressed in this paper is distinct from the process dealt with in previous studies, where the scattering is immersed in the radiation field.

First experimental observation of double-photon Compton scattering using single gamma detector

International Nuclear Information System (INIS)

Sandhu, B.S.; Saddi, M.B.; Singh, B.; Ghumman, B.S.

2003-01-01

Full text: The phenomenon of double-photon Compton scattering has been successfully observed using single gamma detector, a technique avoiding the use of complicated slow-fast coincidence set-up used till now for observing this higher order process. Here doubly differentiated collision cross-section integrated over direction of one of the two final photons, the direction of other one being kept fixed, has been measured experimentally for 0.662 MeV incident gamma photons. The energy spectra of the detected photons are observed as a long tail to the single-photon Compton line on the lower side of the full energy peak in the recorded scattered energy spectrum. The present results are in agreement with theory of this process

Fluorescent L-radiation and the. gamma. -radiation of ionium

Energy Technology Data Exchange (ETDEWEB)

Riou, M

1949-02-21

Irene Curie, Compt. rend. 227, 1225(1948), has shown that the ..gamma..-radiation of ionium is accompanied by a soft radiation that can be identified with the fluorescent L-lines of radium. The present author submitted these radiations to a further study, using as a source a ionium--thorium mixture, (100 mg of hydrate), containing 9% ionium. The Geiger--Mueller counters had 5 mg/cm/sup 2/ aluminum ends and were filled with alcohol + xenon at 10-21 cm Hg. The absorption curves in Cu, Mo, and Ag showed that the energy of the soft radiation was about 14 keV. For the separation of lines, the selective absorption was determined in elements from Z = 28 to Z = 53. The results confirmed the attribution of the spectrum to the L-radiation of Ra. Similar measurements on radioactinium revealed the same lines with approximately the same intensities. In both cases a radium isotope is formed: /sub 90/Th/sup 230/(Io) ..-->.. /sub 88/Ra/sup 226/ ..-->.. ..cap alpha.., /sub 90/Th/sup 227/ (RaAc) ..-->.. /sub 88/Ra/sup 223/ (AcX) + ..cap alpha... The identity of the spectra shows that the atomic number of the formed atom alone determines the L-spectrum, and that in both cases the L level is excited as a result of an internal conversion of ..gamma..-lines: the line 68 keV in the case of ionium, eight lines 26-100 keV in that of radioactinium. On the basis of the intensities found, the relative numbers of photons corresponding to the levels L/sub I/, L/sub II/, and L/sub III/ could be calculated; they are L/sub I/:L/sub II/:L/sub III/ = 50:20:26. The ..gamma..-rays of ionium, as determined from the absorption in Cu, Ta, and Pb, are 68 and 200 kev. By assuming that the efficiency of the counters is equal to 1 - exp (-m..mu../rho), (where m is the efficient superficial mass of xenon, and ..mu../rho is the absorption coefficient in xenon), the intensities of the L- and ..gamma..-radiations of ionium can be given in terms of numbers of quanta per 100 disintegrations.

ZZ SAIL, Albedo Scattering Data Library for 3-D Monte-Carlo Radiation Transport in LWR Pressure Vessel

International Nuclear Information System (INIS)

1982-01-01

1 - Description of problem or function: Format: SAIL format; Number of groups: 23 neutron / 17 gamma-ray; Nuclides: Type 04 Concrete and Low Carbon Steel (A533B). Origin: Science Applications, Inc (SAI); Weighting spectrum: yes. SAIL is a library of albedo scattering data to be used in three-dimensional Monte Carlo codes to solve radiation transport problems specific to the reactor pressure vessel cavity region of a LWR. The library contains data for Type 04 Concrete and Low Carbon Steel (A533B). 2 - Method of solution: The calculation of the albedo data was perform- ed with a version of the discrete ordinates transport code DOT which treats the transport of neutrons, secondary gamma-rays and gamma- rays in one dimension, while maintaining the complete two-dimension- al treatment of the angular dependence

Advanced gamma spectrum processing technique applied to the analysis of scattering spectra for determining material thickness

International Nuclear Information System (INIS)

Hoang Duc Tam; VNUHCM-University of Science, Ho Chi Minh City; Huynh Dinh Chuong; Tran Thien Thanh; Vo Hoang Nguyen; Hoang Thi Kieu Trang; Chau Van Tao

2015-01-01

In this work, an advanced gamma spectrum processing technique is applied to analyze experimental scattering spectra for determining the thickness of C45 heat-resistant steel plates. The single scattering peak of scattering spectra is taken as an advantage to measure the intensity of single scattering photons. Based on these results, the thickness of steel plates is determined with a maximum deviation of real thickness and measured thickness of about 4 %. Monte Carlo simulation using MCNP5 code is also performed to cross check the results, which yields a maximum deviation of 2 %. These results strongly confirm the capability of this technique in analyzing gamma scattering spectra, which is a simple, effective and convenient method for determining material thickness. (author)

Exploring gamma radiation effect on exoelectron emission properties of bone

International Nuclear Information System (INIS)

Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V.

2006-01-01

Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

Exploring gamma radiation effect on exoelectron emission properties of bone

Energy Technology Data Exchange (ETDEWEB)

Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V. [Riga Technical Univ., Biomedical Engineering and Nanotechnology Institute (Latvia)

2006-07-01

Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

Energy distribution of 0. 279 MeV gamma rays Compton scattered from bound electrons

Energy Technology Data Exchange (ETDEWEB)

Singh, B; Singh, P; Singh, G; Ghumman, B S

1984-11-01

Energy and intensity distribution of 0.279 MeV gamma rays Compton scattered from K-shell electrons of tantalum is measured at scattering angle of 70deg. The experimental results are compared with the available theoretical data. Spectral distribution is also obtained as a function of scatterer thickness to account for the contribution of false events. 13 refs.

Research progress in airborne surveys of terrestrial gamma radiation

International Nuclear Information System (INIS)

Burson, Z.G.

1974-01-01

Progress during the last few years in airborne surveys of terrestrial gamma radiation, i.e. in the measuring, recording, and interpreting of gamma ray signals in NaI(Tl) crystals, is discussed. Non-terrestrial background contributions have been accurately characterized. The feasibility of determining the water equivalent of snow cover by aerial survey techniques has been demonstrated. Repeat surveys over areas surrounding reactor sites can now be used to detect average differences of less than 1.0 μR/hr in terrestrial gamma radiation levels. New data acquisition and recording systems allow isotope concentrations and total inventories to be measured in spatial resolutions of a few hundred feet. Aerial survey data have been combined with population distribution data to obtain population exposure values from natural terrestrial gamma radiation around reactor sites

Increase in. gamma. -radiation from powdered milk and beef

Energy Technology Data Exchange (ETDEWEB)

Sievert, R M; Gustafsson, S; Sylander, C G

1956-01-01

Samples of powdered milk and beef preserved during the years 1953 to 1956 were examined for the presence of ..gamma..-radiation. The higher ..gamma..-radiation found in the last year was attributed to an increase in fission products. Data are compared with measurements on a series of children.

Inelastic scattering in condensed matter with high intensity moessbauer radiation

International Nuclear Information System (INIS)

Yelon, W.B.; Schupp, G.

1991-05-01

We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is not fully operational at the University of Missouri Research Reactor (MURR) as well as a facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using Bragg scattering filters to suppress unwanted radiation. These have led to a Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to make a novel independent determination of interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na metal and the charge density wave satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. Using a specially constructed sample cell which enables us to vary temperatures from -10 C to 110 C, we have begun quasielastic diffusion studies in viscous liquids and current results are summarized. Included are the temperature and Q dependence of the scattering in pentadecane and diffusion in glycerol

Environmental gamma radiation levels around various DAE research centres

International Nuclear Information System (INIS)

Takale, R.A.; Swarnakar, M.; Shetty, P.G.; Sahu, S.K.; Pandit, G.G.

2014-01-01

This paper presents the gamma radiation levels of four research centres viz. Bhabha Atomic Research Centre (BARC), Trombay; Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam; Variable Energy Cyclotron Centre (VECC), Kolkata; Raja Ramanna Centre for Advanced Technology (RRCAT), Indore; and an industry Board of Radiation and Isotope Technology (BRIT), Vashi. BARC is India's premier nuclear research facility and is a multi-disciplinary research centre with extensive infrastructure for advanced research and development (R and D). IGCAR, Kalpakkam is engaged in scientific research and advanced engineering programme towards the development of Fast Breeder Reactor technology. VECC Kolkata is dedicated to carry out frontier R and D in the fields of Accelerator Science and Technology, Nuclear Science (Theoretical and Experimental), and Material Science etc. RRCAT, Indore has rapidly grown into a premier institute for R and D in lasers, accelerators and their applications. BRIT, Vashi unit is involved in production, development, and supply of radioisotope based products and provision of isotope applications, radiation processing, radio analytical services etc. With an objective to keep a watch on the prevailing environmental background gamma radiation level around all the DAE installations, routine monitoring programme are being carried out using the Thermo Luminescent Dosimeters (TLDs). TLDs provide the simple, inexpensive and precise measurement of small, integrated, external gamma radiation dose rate. The general practice of this programme is to observe the outdoor gamma radiation levels. This paper summarizes the methodology and gamma radiation levels of four research centres viz. BARC, IGCAR, VECC, RRCAT and an industry BRIT, Vashi

Field Deployable Gamma Radiation Detectors for DHS Use

Energy Technology Data Exchange (ETDEWEB)

Sanjoy Mukhopadhyay

2007-08-01

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

Field Deployable Gamma Radiation Detectors for DHS Use

International Nuclear Information System (INIS)

Sanjoy Mukhopadhyay

2007-01-01

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

Light scattering reviews 9 light scattering and radiative transfer

CERN Document Server

Kokhanovsky, Alexander A

2014-01-01

This book details modern methods of the radiative transfer theory. It presents recent advances in light scattering (measurements and theory) and highlights the newest developments in remote sensing of aerosol and cloud properties.

Effect of gamma radiation on honey quality control

International Nuclear Information System (INIS)

Bera, A.; Almeida-Muradian, L.B.; Sabato, S.F.

2009-01-01

Honey is one of the most complex substances produced by bees, mainly from the nectar of flowers. Gamma radiation is a technique that can be used to decrease the number of microbiological problems associated with food and increase the shelf life of certain products. The objective of this study was to verify the effect of gamma radiation with source of cobalto-60 (10 kGy) on some parameters used in honey quality control. Seven samples of pure honey were obtained from local markets in Sao Paulo, Brazil, in 2007. The methods used are in accordance with Brazilian Regulations. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The results showed that gamma radiation, in the dose mentioned above, did not cause significant physicochemical alterations.

Effect of gamma radiation on honey quality control

Energy Technology Data Exchange (ETDEWEB)

Bera, A. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: berale@usp.br; Almeida-Muradian, L.B. [Av. Prof. Lineu Prestes, 580-Cidade Universitaria, Sao Paulo (Brazil); Sabato, S.F. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: sfsabato@ipen.br

2009-07-15

Honey is one of the most complex substances produced by bees, mainly from the nectar of flowers. Gamma radiation is a technique that can be used to decrease the number of microbiological problems associated with food and increase the shelf life of certain products. The objective of this study was to verify the effect of gamma radiation with source of cobalto-60 (10 kGy) on some parameters used in honey quality control. Seven samples of pure honey were obtained from local markets in Sao Paulo, Brazil, in 2007. The methods used are in accordance with Brazilian Regulations. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The results showed that gamma radiation, in the dose mentioned above, did not cause significant physicochemical alterations.

Gamma radiation in dwellings

International Nuclear Information System (INIS)

Mjoenes, L.

1981-08-01

A nationwide investigation has been made into the gamma radiation in Swedish dwellings. The measurements were made with small detectors containing thermoluminescent dosimeters. The detectors were sent to the selected participants by mail. 1300 dwellings were included in the investigation. In each dwelling three measurements were made: one detector was placed in the kitchen, one in the living-room and one in the bedroom. The mean annual absorbed tissue dose in dwellings in Sweden was found to be 0.65 mGy (corresponding to an exposition rate of 12 μR/h) when the contribution from cosmic radiation had been subtracted. That represents an annual collective dose of about 4000 mansieverts to the population of Sweden. From a previous investigation we have calculate the mean value for the gamma radiation in Swedish dwellings for 1950 to be 0.4 mGy/a (8μR/h). The reason for the relatively large increase in the mean value is an increased use of building materials on stone, particularly of lightweight concrete based on alum shale, from 1940 to middle 1960s. The production of this type of lightweight concrete was discontinued in 1975 and the use of other stone-based building materials has decreased. The mean value of gamma radiation in Swedish dwellings is therefore expected to decrease slowly in the future if this tendency holds. Sweden has some 3.5 million dwellings. About 10 % of them have mean values of 1 mGy/a (19 μR/h) or more, 0.2 % have 3 mGy/a (57 μR/h) or more and a couple of hundred 5 mGy/a (95 μR/h or more. The mean value for detached houses was found to be 0.43 mGy/a (8 μR/h) and for dwellings in multi-family houses 0.80 mGy/a (15 μR/h). The investigation dwellings have also been classified according to the building materials, the year of construction and the degree of urbanization of the area. (author)

SCAP-82, Single Scattering, Albedo Scattering, Point-Kernel Analysis in Complex Geometry

International Nuclear Information System (INIS)

Disney, R.K.; Vogtman, S.E.

1987-01-01

1 - Description of problem or function: SCAP solves for radiation transport in complex geometries using the single or albedo scatter point kernel method. The program is designed to calculate the neutron or gamma ray radiation level at detector points located within or outside a complex radiation scatter source geometry or a user specified discrete scattering volume. Geometry is describable by zones bounded by intersecting quadratic surfaces within an arbitrary maximum number of boundary surfaces per zone. Anisotropic point sources are describable as pointwise energy dependent distributions of polar angles on a meridian; isotropic point sources may also be specified. The attenuation function for gamma rays is an exponential function on the primary source leg and the scatter leg with a build- up factor approximation to account for multiple scatter on the scat- ter leg. The neutron attenuation function is an exponential function using neutron removal cross sections on the primary source leg and scatter leg. Line or volumetric sources can be represented as a distribution of isotropic point sources, with un-collided line-of-sight attenuation and buildup calculated between each source point and the detector point. 2 - Method of solution: A point kernel method using an anisotropic or isotropic point source representation is used, line-of-sight material attenuation and inverse square spatial attenuation between the source point and scatter points and the scatter points and detector point is employed. A direct summation of individual point source results is obtained. 3 - Restrictions on the complexity of the problem: - The SCAP program is written in complete flexible dimensioning so that no restrictions are imposed on the number of energy groups or geometric zones. The geometric zone description is restricted to zones defined by boundary surfaces defined by the general quadratic equation or one of its degenerate forms. The only restriction in the program is that the total

Inverse compton emission of gamma rays near the pulsar surface

International Nuclear Information System (INIS)

Morini, M.

1981-01-01

The physical conditions near pulsar surface that might give rise to gamma ray emission from Crab and Vela pulsars are not yet well understood. Here I suggest that, in the context of the vacuum discharge mechanism proposed by Ruderman and Sutherland (1975), gamma rays are produced by inverse Compton scattering of secondary electrons with the thermal radiation of the star surface as well as for curvature and synchotron radiation. It is found that inverse Compton scattering is relevant if the neutron star surface temperature is greater than 10 6 K or of the polar cap temperature is of the order of 5 x 10 6 K. Inverse Compton scattering in anisotropic photon fields and Klein-Nishina regime is here carefully considered. (orig.)

Ore sorting using natural gamma radiation

International Nuclear Information System (INIS)

Clark, G.J.; Dickson, B.L.; Gray, F.E.

1980-01-01

A method of sorting an ore which emits natural gamma radiation is described, comprising the steps of: (a) mining the ore, (b) placing, substantially at the mining location, the sampled or mined ore on to a moving conveyor belt, (c) measuring the natural gamma emission, water content and mass of the ore while the ore is on the conveyor belt, (d) using the gamma, water content and mass measurements to determine the ore grade, and (e) directing the ore to a location characteristic of its grade when it leaves the conveyor belt

Simultaneous analysis of qualitative parameters of solid fuel using complex neutron gamma method

International Nuclear Information System (INIS)

Dombrovskij, V.P.; Ajtsev, N.I.; Ryashchikov, V.I.; Frolov, V.K.

1983-01-01

A study was made on complex neutron gamma method for simultaneous analysis of carbon content, ash content and humidity of solid fuel according to gamma radiation of inelastic fast neutron scattering and radiation capture of thermal neutrons. Metrological characteristics of pulse and stationary neutron gamma methods for determination of qualitative solid fuel parameters were analyzed, taking coke breeze as an example. Optimal energy ranges of gamma radiation detection (2-8 MeV) were determined. The advantages of using pulse neutron generator for complex analysis of qualitative parameters of solid fuel in large masses were shown

Designing equipment for use in gamma radiation environments

International Nuclear Information System (INIS)

Vandergriff, K.U.

1990-05-01

High levels of gamma radiation are known to cause degradation in a variety of materials and components. When designing systems to operate in a high radiation environment, special precautions and procedures should be followed. This report (1) outlines steps that should be followed in designing equipment and (2) explains the general effects of radiation on various engineering materials and components. Much information exists in the literature on radiation effects upon materials. However, very little information is available to give the designer a step-by-step process for designing systems that will be subject to high levels of gamma radiation, such as those found in a nuclear fuel reprocessing facility. In this report, many radiation effect references are relied upon to aid in the design of components and systems. 11 refs., 4 tabs

First measurement of $Z/\\gamma^{*}$ production in Compton scattering of quasi-real photons

CERN Document Server

Abbiendi, G.; Alexander, G.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Bartoldus, R.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bird, S.D.; Blobel, V.; Bloodworth, I.J.; Bobinski, M.; Bock, P.; Bohme, J.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Burgard, C.; Burgin, R.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Davis, R.; De Jong, S.; del Pozo, L.A.; De Roeck, A.; Desch, K.; Dienes, B.; Dixit, M.S.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Eatough, D.; Estabrooks, P.G.; Etzion, E.; Evans, H.G.; Fabbri, F.; Fanti, M.; Faust, A.A.; Fiedler, F.; Fierro, M.; Fleck, I.; Folman, R.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon, J.; Gascon-Shotkin, S.M.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Hargrove, C.K.; Hartmann, C.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hillier, S.J.; Hobson, P.R.; Hocker, James Andrew; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Koetke, D.S.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kyberd, P.; Lafferty, G.D.; Lanske, D.; Lauber, J.; Lautenschlager, S.R.; Lawson, I.; Layter, J.G.; Lazic, D.; Lee, A.M.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Ludwig, J.; Lui, D.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Markopoulos, C.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menke, S.; Merritt, F.S.; Mes, H.; Meyer, J.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nellen, B.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Oreglia, M.J.; Orito, S.; Palinkas, J.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Polok, J.; Przybycien, M.; Rembser, C.; Rick, H.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharf, F.; Scharff-Hansen, P.; Schieck, J.; Schmitt, B.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seiler, T.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Sittler, A.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Sproston, M.; Stahl, A.; Stephens, K.; Steuerer, J.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Tanaka, S.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomson, M.A.; von Torne, E.; Torrence, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turcot, A.S.; Turner-Watson, M.F.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Yekutieli, G.; Zacek, V.; Zer-Zion, D.

1998-01-01

We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the final state electrons is undetected. Approximately 55 pb-1 of data collected in the year 1997 at an e+e- centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been analysed. The Z/gamma* from Compton scattering has been detected in the hadronic decay channel. Within well defined kinematic bounds, we measure the product of cross-section and Z/gamma* branching ratio to hadrons to be (0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV, dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60 GeV, dominated by (e)egamma* production, this product is found to be (4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo event generators, grc4f and PYTHIA.

Attenuation studies near K-absorption edges using Compton scattered 241Am gamma rays

International Nuclear Information System (INIS)

Abdullah, K.K.; Ramachandran, N.; Karunakaran Nair, K.; Babu, B.R.S.; Joseph, Antony; Thomas, Rajive; Varier, K.M.

2008-01-01

We have carried out photon attenuation measurements at several energies in the range from 49.38 keV to 57.96 keV around the K-absorption edges of the rare earth elements Sm, Eu, Gd, Tb, Dy and Er using 59.54 keV gamma rays from 241 Am source after Compton scattering from an aluminium target. Pellets of oxides of the rare earth elements were chosen as mixture absorbers in these investigations. A narrow beam good geometry set-up was used for the attenuation measurements. The scattered gamma rays were detected by an HPGe detector. The results are consistent with theoretical values derived from the XCOM package. (author)

Spatial distribution of reflected gamma rays by Monte Carlo simulation

International Nuclear Information System (INIS)

Jehouani, A.; Merzouki, A.; Boutadghart, F.; Ghassoun, J.

2007-01-01

In nuclear facilities, the reflection of gamma rays of the walls and metals constitutes an unknown origin of radiation. These reflected gamma rays must be estimated and determined. This study concerns reflected gamma rays on metal slabs. We evaluated the spatial distribution of the reflected gamma rays spectra by using the Monte Carlo method. An appropriate estimator for the double differential albedo is used to determine the energy spectra and the angular distribution of reflected gamma rays by slabs of iron and aluminium. We took into the account the principal interactions of gamma rays with matter: photoelectric, coherent scattering (Rayleigh), incoherent scattering (Compton) and pair creation. The Klein-Nishina differential cross section was used to select direction and energy of scattered photons after each Compton scattering. The obtained spectra show peaks at 0.511 * MeV for higher source energy. The Results are in good agreement with those obtained by the TRIPOLI code [J.C. Nimal et al., TRIPOLI02: Programme de Monte Carlo Polycinsetique a Trois dimensions, CEA Rapport, Commissariat a l'Energie Atomique.

Experimental arrangement for production and use of gamma radiation from neutron capture

International Nuclear Information System (INIS)

Mafra, Olga Yajgunovitch

1969-01-01

This dissertation presents the main characteristics and construction details of collimator system for gamma radiation emitted by atomic nuclei after capturing thermal neutrons. This construction was made in one of the cross channels of IEAR-1 swimming pool reactor of the Atomic Energy Institute of Sao Paulo, Brazil. The energies of gamma radiation available vary range from about 4 MeV and 11 MeV, discreetly. With this experimental arrangement is obtained: high intensity, good collimation and monochrome gamma radiation, important for conducting experiments with gamma radiation. It is also present in this dissertation the description of the techniques employed in determining the intensity of gamma radiation and the extent of contamination in the neutron beam as well as the program list GAMAU that adjusts the gamma spectrum photopeak taken as a Gaussian curve. We intend to use this experimental arrangement for the measurement of cross sections of photonuclear reactions

Effect of gamma radiation on chemical composition and storability of lime RTS

International Nuclear Information System (INIS)

Pandey, S.K.; Bisen, A.; Dwivedi, V.

2008-01-01

In the present investigation, the RTS was irradiated with different doses of gamma radiation to study their effect on chemical composition and storability of lime RTS and vitamin C content only was influenced significantly by 50 Gy gamma radiation during storage (16 days) without adversely affecting the quality of lime fruits, whereas, under control and higher doses of gamma radiation, the quality of lime RTS was deteriorated. The irradiation of lime with 50 Gy gamma radiation may be useful for extending storability of lime of RTS and stabilizing the market demand. (author)

Sensitiveness of jasmine cuttings to gamma radiation

International Nuclear Information System (INIS)

Devaiah, K.A.; Srivastava, H.C.

1989-01-01

Half lethal dose (LD 50 ) gamma radiation for five genotypes of jasmine and the effect of such radiation on their rooting parameters were studied. The LD 50 was close to 2.5 krad for Jasminum grandiflorum var. Pink Pin, 0.5 krad for var. Pink Thrum, 2.5 krad for J. flexile Valh., 1 krad for J. calophyllum Wall and 2 krad for J. sambac Ait var. 'Gundumalli'. Percentage of rooting, number of roots per cutting, length and thickness of roots decreased with increase in intensity of gamma irradiation. (author) 8 refs.; 4 tabs

Measurements of computed tomography radiation scatter

International Nuclear Information System (INIS)

Van Every, B.; Petty, R.J.

1992-01-01

This paper describes the measurement of scattered radiation from a computed tomography (CT) scanner in a clinical situation and compares the results with those obtained from a CT performance phantom and with data obtained from CT manufacturers. The results are presented as iso-dose contours. There are significant differences between the data obtained and that supplied by manufacturers, both in the shape of the iso-dose contours and in the nominal values. The observed scatter in a clinical situation (for an abdominal scan) varied between 3% and 430% of the manufacturers' stated values, with a marked reduction in scatter noted a the head and feet of the patient. These differences appear to be due to the fact that manufacturers use CT phantoms to obtain scatter data and these phantoms do not provide the same scatter absorption geometry as patients. CT scatter was observed to increase as scan field size and slice thickness increased, whilst there was little change in scatter with changes in gantry tilt and table slew. Using the iso-dose contours, the orientation of the CT scanner can be optimised with regard to the location and shielding requirements of doors and windows. Additionally, the positioning of staff who must remain in the room during scanning can be optimised to minimise their exposure. It is estimated that the data presented allows for realistic radiation protection assessments to be made. 13 refs., 5 tabs., 6 figs

Effect of gamma radiation on optical and electrical properties of ...

Indian Academy of Sciences (India)

Wintec

Tellurium dioxide; thin films; optical bandgap; gamma radiation dose; dosimeter. 1. Introduction. It is now ... material to ionizing radiations (such as X-rays, gamma rays, beta ..... Mag. 19 19. Mott N F and Davis E 1979 Electronic process in non-.

Transient radiative transfer in a scattering slab considering polarization.

Science.gov (United States)

Yi, Hongliang; Ben, Xun; Tan, Heping

2013-11-04

The characteristics of the transient and polarization must be considered for a complete and correct description of short-pulse laser transfer in a scattering medium. A Monte Carlo (MC) method combined with a time shift and superposition principle is developed to simulate transient vector (polarized) radiative transfer in a scattering medium. The transient vector radiative transfer matrix (TVRTM) is defined to describe the transient polarization behavior of short-pulse laser propagating in the scattering medium. According to the definition of reflectivity, a new criterion of reflection at Fresnel surface is presented. In order to improve the computational efficiency and accuracy, a time shift and superposition principle is applied to the MC model for transient vector radiative transfer. The results for transient scalar radiative transfer and steady-state vector radiative transfer are compared with those in published literatures, respectively, and an excellent agreement between them is observed, which validates the correctness of the present model. Finally, transient radiative transfer is simulated considering the polarization effect of short-pulse laser in a scattering medium, and the distributions of Stokes vector in angular and temporal space are presented.

Physics of radiation

International Nuclear Information System (INIS)

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

2004-01-01

This chapter discusses the following topics: concept of atom and elements; molecules and compounds; basic principles of radiation; types of radiations; radioactivity, unit of radioactivity, specific activity, radioactive decay, ionisation and ions, interaction of radiation with matters, modes of interaction: photoelectric absorption: Compton scattering, pair-production; attenuation of x and gamma radiation; build-up factors

Residual water treatment for gamma radiation. Tratamiento de aguas residuales por radiacion gamma

Energy Technology Data Exchange (ETDEWEB)

Mendez, L [Universidad Nacional Mayor de San Marcos. Facultad de Quimica (Peru)

1990-07-01

The treatment of residual water by means of gamma radiation for its use in agricultural irrigation is evaluated. Measurements of physical, chemical, biological and microbiological contamination indicators were performed. For that, samples from the treatment center of residual water of San Juan de Miraflores were irradiated up to a 52.5 kGy dose. The study concludes that gamma radiation is effective to remove parasites and bacteria, but not for removal of the organic and inorganic matter. (author). 15 refs., 3 tabs., 4 figs.

Gastric emptying of liquid meals: validation of the gamma camera technique

Energy Technology Data Exchange (ETDEWEB)

Lawaetz, Otto; Dige-Petersen, Harriet

1989-05-01

To assess the extent of errors and to provide correction factors for gamma camera gastric emptying studies of liquid meals labelled with radionuclides (/sup 99/Tc/sup m/ or /sup 113/In/sup m/), phantom studies were performed with different gastric emptying procedures, gamma cameras and data handling systems. To validate the overall accuracy of the method, 24 combined aspiration and gamma camera gastric emptying studies were carried out in three normal volunteers. Gastric meal volume was underestimated due to scattered radiation from the stomach. The underestimation was 7-20% varying with the size of the gastric region of interest (ROI), the energy of the nuclide and the fraction of meal in the stomach. The overestimation, due to scattered radiation from the gut, was negligible (1-3%) for any of the procedures. The gamma camera technique eliminated much of the error due to variations of stomach geometry and produced accurate quantitative gastric emptying data comparable to those obtained by evacuation (P > 0.10), when the entire field maximum 1-min count achieved within the first 20 min of a study was taken as representing the original volume of the meal ingested, and when corrections for area related errors due to scattered radiation from the stomach were performed. (author).

High-energy gamma-ray emission in compact binaries

International Nuclear Information System (INIS)

Cerutti, Benoit

2010-01-01

Four gamma-ray sources have been associated with binary systems in our Galaxy: the micro-quasar Cygnus X-3 and the gamma-ray binaries LS I +61 degrees 303, LS 5039 and PSR B1259-63. These systems are composed of a massive companion star and a compact object of unknown nature, except in PSR B1259-63 where there is a young pulsar. I propose a comprehensive theoretical model for the high-energy gamma-ray emission and variability in gamma-ray emitting binaries. In this model, the high-energy radiation is produced by inverse Compton scattering of stellar photons on ultra-relativistic electron-positron pairs injected by a young pulsar in gamma-ray binaries and in a relativistic jet in micro-quasars. Considering anisotropic inverse Compton scattering, pair production and pair cascade emission, the TeV gamma-ray emission is well explained in LS 5039. Nevertheless, this model cannot account for the gamma-ray emission in LS I +61 degrees 303 and PSR B1259-63. Other processes should dominate in these complex systems. In Cygnus X-3, the gamma-ray radiation is convincingly reproduced by Doppler-boosted Compton emission of pairs in a relativistic jet. Gamma-ray binaries and micro-quasars provide a novel environment for the study of pulsar winds and relativistic jets at very small spatial scales. (author)

Magnetic X-Ray Scattering with Synchrotron Radiation

DEFF Research Database (Denmark)

Moncton, D. E.; Gibbs, D.; Bohr, Jakob

1986-01-01

With the availability of high-brilliance synchrotron radiation from multiple wigglers, magnetic X-ray scattering has become a powerful new probe of magnetic structure and phase transitions. Similar to the well-established magnetic neutron scattering technique, magnetic X-ray scattering methods have...... many complementary advantages. A brief review is presented of the history of magnetic X-ray scattering as well as recent results obtained in studies of the rare-earth magnet holmium with emphasis on instrumentational aspects. In particular, the development of a simple polarization analyzer...... to distinguish charge and magnetic scattering is described....

Effect of gamma radiation on ''in vitro''' efficiency of fungicides

International Nuclear Information System (INIS)

Menten, J.O.M.; Oliveira, G.C.X.

1984-01-01

The activity of 60 Co gamma radiation on eight fungicides used in post-harvesting treatment of agricultural products, was studied. Rhizoctonia solani was used in biological test as indicator-fungus. The fungicides were submitted to gamma radiation doses of O (control), 1, 10, 100, 1000 and 10.000 kR, samples of the fungicides were added to the PSA culture media to obtain 0, 1, 10 and 100 ppm concentrations of the active component of each product and of each radiation dose. The ED 50 (concentration of fungicide necessary to cause 50% radial reduction of the fungic mycelium) of each fungicide in the different gamma radiation doses was determined. (M.A.C.) [pt

Scattering of light and other electromagnetic radiation

CERN Document Server

Kerker, Milton

1969-01-01

The Scattering of Light and Other Electromagnetic Radiation discusses the theory of electromagnetic scattering and describes some practical applications. The book reviews electromagnetic waves, optics, the interrelationships of main physical quantities and the physical concepts of optics, including Maxwell's equations, polarization, geometrical optics, interference, and diffraction. The text explains the Rayleigh2 theory of scattering by small dielectric spheres, the Bessel functions, and the Legendre functions. The author also explains how the scattering functions for a homogenous sphere chan

Inelastic scattering in condensed matter with high intensity Moessbauer radiation

International Nuclear Information System (INIS)

Yelon, W.B.; Schupp, G.

1990-10-01

We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is now fully operational at the University of Missouri Research Reactor (MURR) as well as facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using scattering to filter the unwanted radiation. These have led to a new Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption (SRSA) and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to more precisely determine interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both the fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na and the satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. We have begun quasielastic diffusion studies in viscous liquids and current results are summarized. These advances, coupled to our improvements in MIcrofoil Conversion Electron spectroscopy lay the foundation for the proposed research outlined in this request for a three-year renewal of DOE support

Dose Rate of Environmental Gamma Radiation in Java Island

International Nuclear Information System (INIS)

Gatot Suhariyono; Buchori; Dadong Iskandar

2007-01-01

The dose rate Monitoring of environmental gamma radiation at some locations in Java Island in the year 2005 / 2006 has been carried out. The dose rate measurement of gamma radiation is carried out by using the peripheral of Portable Gamma of Ray Spectrometer with detector of NaI(Tl), Merck Exploranium, Model GR-130- MINISPEC, while to determine its geographic position is used by the GPS (Global Positioning System), made in German corporation of GPS III Plus type. The division of measurement region was conducted by dividing Java Island become 66 parts with same distance, except in Jepara area that will built PLTN (Nuclear Energy Power), distance between measurement points is more closed. The results of dose rate measurement are in 66 locations in Java Island the range of (19.24 ± 4.05) nSv/hour until (150.78 ± 12.26) nSv/hour with mean (51.93 ± 36.53) nSv/h. The lowest dose rate was in location of Garut, while highest dose rate was in Ujung Lemah Abang, Jepara location. The data can be used for base line data of dose rate of environmental gamma radiation in Indonesia, specially in Java Island. The mean level of gamma radiation in Java monitoring area (0.46 mSv / year) was still lower than worldwide average effective dose rate of terrestrial gamma rays 0.5 mSv / year (report of UNSCEAR, 2000). (author)

Measurement of Z dependence of elastic scattering cross-sections of 0. 145 MeV gamma rays

Energy Technology Data Exchange (ETDEWEB)

Ghumman, B S [Punjabi Univ., Patiala (India). Dept. of Physics

1981-11-01

The Z dependence of elastic scattering cross-sections of 0.145 MeV gamma rays is investigated at large scattering angles. Measurements are made with scatterers of Pb, W, Sn, Ag, Mo, Zn, Cu, Fe and Al at scattering angles from 75 deg to 150 deg. The experimental results are compared with the available theoretical and experimental data.

Gamma radiation effects on peanut skin antioxidants

International Nuclear Information System (INIS)

Camargo, Adriano Costa de; Canniatti-Brazaca, Solange Guidolin; Vieira, Thais Maria Ferreira de Souza; Regitano-d'Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia

2011-01-01

Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The viability of using natural sources of antioxidants to replace synthetic antioxidants was assessed. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays at a dose rate of 7.5 kGy/h using a 60 Co source. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached deodorized (RBD) soybean oil that was free from synthetic antioxidants. The oxidative stability of the oil samples was determined using the Rancimat method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. Ethanolic extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Rancimat method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT but lower than THBQ. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative level when added to soybean oil. The induction period of the control soybean oil was 5.7 h, while soybean oil with added ethanolic peanut skin extract had an induction period of 7.2 h, on average. (author)

Gamma radiation effects on peanut skin antioxidants

Energy Technology Data Exchange (ETDEWEB)

Camargo, Adriano Costa de [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Canniatti-Brazaca, Solange Guidolin; Vieira, Thais Maria Ferreira de Souza; Regitano-d' Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia, E-mail: sgcbraza@usp.b, E-mail: tvieira@esalq.usp.b, E-mail: mabra@esalq.usp.b, E-mail: macdomin@esalq.usp.b [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao

2011-07-01

Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The viability of using natural sources of antioxidants to replace synthetic antioxidants was assessed. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays at a dose rate of 7.5 kGy/h using a {sup 60}Co source. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached deodorized (RBD) soybean oil that was free from synthetic antioxidants. The oxidative stability of the oil samples was determined using the Rancimat method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. Ethanolic extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Rancimat method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT but lower than THBQ. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative level when added to soybean oil. The induction period of the control soybean oil was 5.7 h, while soybean oil with added ethanolic peanut skin extract had an induction period of 7.2 h, on average. (author)

Development of a novel gamma probe for detecting radiation direction

Science.gov (United States)

Pani, R.; Pellegrini, R.; Cinti, M. N.; Longo, M.; Donnarumma, R.; D'Alessio, A.; Borrazzo, C.; Pergola, A.; Ridolfi, S.; De Vincentis, G.

2016-01-01

Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security.

Development of a novel gamma probe for detecting radiation direction

International Nuclear Information System (INIS)

Pani, R.; Pellegrini, R.; Cinti, M.N.; Longo, M.; Donnarumma, R.; Borrazzo, C.; D'Alessio, A.; Pergola, A.; Ridolfi, S.; Vincentis, G. De

2016-01-01

Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security

Somatic mutation frequency in the stamen hairs of Tradescantia KU 7 and KU 9 clones exposed to low-level gamma rays

International Nuclear Information System (INIS)

Ichikawa, S.; Nagashima, C.; Takahashi, C.S.

1981-01-01

Two triploid clones (KU 7 and KU 9) of Tradescantia heterozygous for flower color were exposed to 1 to 42.3R of gamma rays or the scattering radiation in the gamma field of the Institute of Radiation . Breeding. Occurrence of somatic pink mutations in the stamen hairs was investigated 10 to 16 (or 14) days after irradiation. The mutation frequency was found to increase linearly with increasing gamma-ray exposure in the both clones, and the frequencies of 0.437 and 0.468 pink mutant events per 10 3 hairs per R were determined for KU 7 and KU 9, respectively. When the data collected in the present study were analyzed together with those obtained in earlier experiments in the gamma field, linear relationships of the somatic mutation frequency with gamma-ray (2.1 to 201.6R) and scattering radiation (0.72 to 57.6R) exposures were confirmed. Scattering radiation was found to have a genetical efficiency more than two times higher than that of gamma rays. Variation of spontaneous mutation frequency observed in the present study and in earlier studies was inversely correlated to temperature variation

Effect of gamma radiation on polyvinylpyrrolidone hydrogels

International Nuclear Information System (INIS)

Oliveira, M.J.A.; Vásquez, P.A.S.; Alcântara, M.T.S.; Munhoz, M.M.L.; Lugão, A.B.

2017-01-01

Polyvinylpyrrolidone (PVP) hydrogels have been investigated as drug delivery matrices for the treatment of wounds, such as cutaneous leishmaniasis, and matrices with silver nanoparticles for chronic wounds and burns. The preparation of such hydrogels can occur by various cross-linking methods, such as gamma, chemical, physical, among others. The most feasible for wound dressings is gamma irradiation from cobalt-60, because gamma irradiation simultaneously promotes crosslinking and sterilization, leaving the wound dressing ready for use. The objective of this work was to investigate the effect on physico- chemical properties of gamma radiation on PVP hydrogel according to the radiation absorbed dose variation. The PVP hydrogels were irradiated with doses of 5, 15, 25, 35, 45, 55, 65, 75 and 95kGy at dose rate of 5 kGy/h and characterized by swelling, thermogravimetric and mechanical analysis. Results shown a favorable dose range window for processing of these hydrogels related to the application. The results showed that mechanical strength was affected at doses starting at 25 kGy. (author)

Effect of gamma radiation on polyvinylpyrrolidone hydrogels

Energy Technology Data Exchange (ETDEWEB)

Oliveira, M.J.A.; Vásquez, P.A.S.; Alcântara, M.T.S.; Munhoz, M.M.L.; Lugão, A.B., E-mail: mariajhho@yahoo.com.br, E-mail: pavsalva@ipen.br, E-mail: ablugao@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Polyvinylpyrrolidone (PVP) hydrogels have been investigated as drug delivery matrices for the treatment of wounds, such as cutaneous leishmaniasis, and matrices with silver nanoparticles for chronic wounds and burns. The preparation of such hydrogels can occur by various cross-linking methods, such as gamma, chemical, physical, among others. The most feasible for wound dressings is gamma irradiation from cobalt-60, because gamma irradiation simultaneously promotes crosslinking and sterilization, leaving the wound dressing ready for use. The objective of this work was to investigate the effect on physico- chemical properties of gamma radiation on PVP hydrogel according to the radiation absorbed dose variation. The PVP hydrogels were irradiated with doses of 5, 15, 25, 35, 45, 55, 65, 75 and 95kGy at dose rate of 5 kGy/h and characterized by swelling, thermogravimetric and mechanical analysis. Results shown a favorable dose range window for processing of these hydrogels related to the application. The results showed that mechanical strength was affected at doses starting at 25 kGy. (author)

Bioburden assessment and gamma radiation inactivation patterns in parchment documents

International Nuclear Information System (INIS)

Nunes, Inês; Mesquita, Nuno; Cabo Verde, Sandra; Carolino, Maria Manuela; Portugal, António; Botelho, Maria Luísa

2013-01-01

Parchment documents are part of our cultural heritage and, as historical artifacts that they are, should be preserved. The aim of this study was to validate an appropriate methodology to characterize the bioburden of parchment documents, and to assess the growth and gamma radiation inactivation patterns of the microbiota present in that material. Another goal was to estimate the minimum gamma radiation dose (D min ) to be applied for the decontamination of parchment as an alternative treatment to the current toxic chemical and non-chemical decontamination methods. Two bioburden assessment methodologies were evaluated: the Swab Method (SM) and the Destructive Method (DM). The recovery efficiency of each method was estimated by artificial contamination, using a Cladosporium cladosporioides spore suspension. The parchment samples' microbiota was typified using morphological methods and the fungal isolates were identified by ITS-DNA sequencing. The inactivation pattern was assessed using the DM after exposure to different gamma radiation doses, and using C. cladosporioides as reference. Based on the applied methodology, parchment samples presented bioburden values lower than 5×10 3 CFU/cm 2 for total microbiota, and lower than 10 CFU/cm 2 for fungal propagules. The results suggest no evident inactivation trend for the natural parchment microbiota, especially regarding the fungal community. A minimum gamma radiation dose (D min ) of 5 kGy is proposed for the decontamination treatment of parchment. Determining the minimal decontamination dose in parchment is essential for a correct application of gamma radiation as an alternative decontamination treatment for this type of documents avoiding the toxicity and the degradation promoted by the traditional chemical and non-chemical treatments. - Highlights: • Characterization of the microbial population of parchment documents. • Study the inactivation pattern of parchment microbiota by gamma radiation. • Assessment of

Gamma radiation effect study in polycarbonate optical and mechanics properties

International Nuclear Information System (INIS)

Araujo, E.S. de.

1991-02-01

Polycarbonates (PC) are used in different industrial applications due to their excellent dielectric characteristics, impact resistance, and high temperature resistance. In some of these applications, the polycarbonates are exposed to gamma radiation which produces molecular scissions, causing changes in the polycarbonate properties. To estimate the radiation effects in the Durolon polycarbonate, samples were irradiated with 60 Co gamma rays with doses between 0,2 kGy and 300 kGy. The results obtained showed that the PC mechanical properties are not changed due to the gamma radiation. However the results showed an expressive variation in the yellowness index for doses above 1 kGy. The results showed that it is possible to use the gamma sterilization of PC in applications where the coloration of PC is not critical. (author). 21 refs, 25 figs, 3 tabs

Monte Carlo simulation of the scattered component of neutron capture prompt gamma-ray analyzer responses

International Nuclear Information System (INIS)

Jin, Y.; Verghese, K.; Gardner, R.P.

1986-01-01

This paper describes a major part of our efforts to simulate the entire spectral response of the neutron capture prompt gamma-ray analyzer for bulk media (or conveyor belt) samples by the Monte Carlo method. This would allow one to use such a model to augment or, in most cases, essentially replace experiments in the calibration and optimum design of these analyzers. In previous work, we simulated the unscattered gamma-ray intensities, but would like to simulate the entire spectral response as we did with the energy-dispersive x-ray fluorescence analyzers. To accomplish this, one must account for the scattered gamma rays as well as the unscattered and one must have available the detector response function to translate the incident gamma-ray spectrum calculated by the Monte Carlo simulation into the detected pulse-height spectrum. We recently completed our work on the germanium detector response function, and the present paper describes our efforts to simulate the entire spectral response by using it with Monte Carlo predicted unscattered and scattered gamma rays

Studying and measuring the gamma radiation doses in Homs city

International Nuclear Information System (INIS)

Sofaan, A. H.

2001-01-01

The gamma radiation dose was measured in Homs city by using many portable dosimeters (electronic dosimeter and Geiger-Muller). The measurements were carried out in the indoor and outdoor buildings, for different time period, through one year (1999-2000). High purity germanium detector with low back ground radiation (HpGe) was used to determine radiation element contained in some building and the surrounding soil. The statistical analysis laws were applied to make sure that the measured dose distribution around average value is normal distribution. The measurement indicates that the gamma indoor dose varies from 312μSv/y to 511μSv/y, with the average annual dose of 385μSv/y. However the gamma outdoor dose rate varies from 307μSv/y to 366μSv/y with an average annual dose 385μSv/y. The annual outdoor gamma radiation dose is about %16 lower than the outdoor dose in Homs City. These measurements have indicated that environmental gamma doses in Homs City are relatively low. This is because that most of the soils and rocks in the area are limestone. (author)

Brilliant GeV gamma-ray flash from inverse Compton scattering in the QED regime

Science.gov (United States)

Gong, Z.; Hu, R. H.; Lu, H. Y.; Yu, J. Q.; Wang, D. H.; Fu, E. G.; Chen, C. E.; He, X. T.; Yan, X. Q.

2018-04-01

An all-optical scheme is proposed for studying laser plasma based incoherent photon emission from inverse Compton scattering in the quantum electrodynamic regime. A theoretical model is presented to explain the coupling effects among radiation reaction trapping, the self-generated magnetic field and the spiral attractor in phase space, which guarantees the transfer of energy and angular momentum from electromagnetic fields to particles. Taking advantage of a prospective ˜ 1023 W cm-2 laser facility, 3D particle-in-cell simulations show a gamma-ray flash with unprecedented multi-petawatt power and brightness of 1.7 × 1023 photons s-1 mm-2 mrad-2/0.1% bandwidth (at 1 GeV). These results bode well for new research directions in particle physics and laboratory astrophysics exploring laser plasma interactions.

Dibasic calcium phosphate dihydrate, USP material compatibility with gamma radiation

Science.gov (United States)

Betancourt Quiles, Maritza

Gamma radiation is a commonly used method to reduce the microbial bioburden in compatible materials when it is applied at appropriate dose levels. Gamma irradiation kills bacteria and mold by breaking down the organism’s DNA and inhibiting cell division. The purpose of this study is to determine the radiation dosage to be used to treat Dibasic Calcium Phosphate Dihydrate, USP (DCPD) and to evaluate its physicochemical effects if any, on this material. This material will be submitted to various doses of gamma radiation that were selected based on literature review and existing regulations that demonstrate that this method is effective to reduce or eliminate microbial bioburden in natural source and synthetic materials. Analytical testing was conducted to the DCPD exposed material in order to demonstrate that gamma radiation does not alter the physicochemical properties and material still acceptable for use in the manufacture of pharmaceutical products. The results obtained through this study were satisfactory and demonstrated that the gamma irradiation dosages from 5 to 30 kGy can be applied to DCPD without altering its physicochemical properties. These are supported by the Assay test data evaluation of lots tested before and after gamma irradiation implementation that show no significant statistical difference between irradiated and non irradiated assay results. The results of this study represent an achievement for the industry since they provide as an alternative the use of Gamma irradiation technology to control the microbial growth in DCPD.

On the omnipresent background gamma radiation of the continuous spectrum

Energy Technology Data Exchange (ETDEWEB)

Banjanac, R.; Maletić, D.; Joković, D., E-mail: yokovic@ipb.ac.rs; Veselinović, N.; Dragić, A.; Udovičić, V.; Aničin, I.

2014-05-01

The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere, is studied by means of absorption measurements, both in a ground level and in an underground laboratory. The low-energy continuous portion of this background spectrum that peaks at around 100 keV, which is its most intense component, is found to be of very similar shape at the two locations. It is established that it is mostly due to the radiations of the real continuous spectrum, which is quite similar to the instrumental one. The intensity of this radiation is in our cases estimated to about 8000 photons/(m{sup 2}s·2π·srad) in the ground level laboratory, and to about 5000 photons/(m{sup 2}s·2π·srad) in the underground laboratory, at the depth of 25 m.w.e. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is predominantly of terrestrial origin, due to environmental gamma radiations scattered off the materials that surround the detector (the “skyshine radiation”), and to a far less extent to cosmic rays of degraded energy. - Highlights: • We studied the low-energy part of continuous background spectra of germanium detectors. • The study was performed at the ground level and at the shallow underground sites. • The instrumental spectrum is due to radiations of the similar continuous spectrum. • The low-energy radiation is of both terrestrial and cosmic-ray origin. • In our study, we find that this radiation is of predominantly terrestrial origin.

Distance factor on reducing scattered radiation risk during interventional fluoroscopy

International Nuclear Information System (INIS)

Husaini Salleh; Mohd Khalid Matori; Muhammad Jamal Mat Isa; Zainal Jamaluddin; Mohd Firdaus Abdul Rahman; Mohd Khairusalih Mohd Zin

2012-01-01

Interventional Radiology (IR) is subspecialty of diagnostic radiology where minimally invasive procedures are performed using an x-ray as a guidance. This procedure can deliver high radiation doses to patient and medical staff compared with other radiological method due to long screening time. The use of proper shielding, shorten the exposure time and keep the distance are the practices to reduce scattered radiation risks to staff involve in this procedure. This project is to study the distance factor on reducing the scattered radiation effect to the medical staff. It also may provide the useful information which can be use to establish the scattered radiation profile during the IR for the sake of radiation protection and safety to the medical staff involved. (author)

Prompt Gamma Radiation from Fragments in the Thermal Fission of 235U

International Nuclear Information System (INIS)

Albinsson, H.; Lindow, L.

1970-06-01

Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of 235 U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from 252 Cf-fission. Attention is drawn to some features which seem to be the same in 235 U and 252 Cf-fission

Quality assurance of environmental gamma radiation monitoring in Slovenia

International Nuclear Information System (INIS)

Stuhec, M.; Zorko, B.; Mitic, D.; Miljanic, S.; Ranogajec-Komor, M.

2006-01-01

Environmental gamma radiation monitoring established in Slovenia consists of a network of multifunctional gamma monitors (MFMs) based on pairs of Geiger-Mueller counters and a network of measuring sites with high-sensitive thermoluminescence dosemeters. The measuring points are evenly spread across Slovenia, located at the meteorological stations and more densely on additional locations around the Krsko NPP. The MFM network has a 2-fold function with one sensor used for the purpose of early warning system in near surroundings of the NPP and the other, more sensitive, for natural radiation monitoring. The paper summarises activities to establish quality assurance of the environmental gamma radiation measurements in Slovenia, with a critical view of the results in comparison with the international standards and recommendations. While the results of linearity and energy dependence tests were satisfying, on-field intercomparison showed that the inherent signal of one of the monitors (MFM) has to be taken into account in the range of environmental background radiation. (authors)

Gamma radiation from PSR B1055-52

DEFF Research Database (Denmark)

Thompson, D.J.; Bailes, M.; Bertsch, D.L.

1999-01-01

The telescopes on the Compton Gamma Ray Observatory (CGRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics that distinguish this pulsar: the light...... curve is complex; there is no detectable unpulsed emission; the energy spectrum is hat, with no evidence of a sharp high-energy cutoff up to greater than 4 GeV. Comparisons of the gamma-ray data with observations at longer wavelengths show that no two of the known gamma-ray pulsars have quite the same...

Ornithogalum virens as a plant assay for beta and gamma radiation effects

International Nuclear Information System (INIS)

Herron, V.J.

1979-01-01

The purpose of this study was to determine if the monocotyledonous angiosperm, Ornithogalum virens (Quintanilha and Cabral, 1947), could be used in such a biological assay system. After exposing O. virens plants to acute ( 60 Co) and chronic ( 137 Cs) gamma radiation and internal beta radiation ( 32 P), lethality (LD 50 , LD 100 ), growth inhibition, and chromosome aberrations were investigated. The LD 50 and LD 100 for acute gamma radiation were estimated to be between 0.91 to 1.8 krad and less than 3.6 krad, respectively. Though growth inhibition and abnormal growth were observed in the acute and chronic gamma radiation studies, the changes in the growth of the plants were so variable that these parameters were found to be unreliable measures of radiation effects. Chromosome aberrations were a more reliable measure of radiation damage because linear relationships between total aberrations and dose were found for both gamma and beta radiation

X-ray echoes from gamma-ray bursts

International Nuclear Information System (INIS)

Dermer, C.D.; Hurley, K.C.; Hartmann, D.H.

1991-01-01

The identification of an echo of reflected radiation in time histories of gamma-ray burst spectra can provide important information about the existence of binary companions or accretion disks in gamma-ray burst systems. Because of the nature of Compton scattering, the spectrum of the echo will be attenuated at gamma-ray energies compared with the spectrum of the primary burst emission. The expected temporal and spectral signatures of the echo and a search for such echoes are described, and implications for gamma-ray burst models are discussed. 35 refs

Lethality of gamma radiation and malathion to the indian meal moth, plodia interpunctella

International Nuclear Information System (INIS)

Eesa, N.M.; Moursy, L.E.

1991-01-01

The lethality of gamma radiation and the organo phosphorous insecticide, malathion, as well as the combined action of both was determined for the five larval instars of the indian meal moth, plodia interpunctella (Hubner). The younger instars were more susceptible to both gamma radiation and malathion. The L D 50 values of gamma radiation increased gradually with the instar. Malathion was highly toxic to the first four instars, but the fifth instar required a much larger dose. Gamma radiation combined with malathion at the L D 25 values was antagonistic when evaluated against each of the five larval instars of the indian meal moth. Thus, the use of gamma radiation with malathion does not seem to be a promising control strategy. However, further research investigations are needed to confirm this finding.3 tab

A didactic experiment showing the Compton scattering by means of a clinical gamma camera.

Science.gov (United States)

Amato, Ernesto; Auditore, Lucrezia; Campennì, Alfredo; Minutoli, Fabio; Cucinotta, Mariapaola; Sindoni, Alessandro; Baldari, Sergio

2017-06-01

We describe a didactic approach aimed to explain the effect of Compton scattering in nuclear medicine imaging, exploiting the comparison of a didactic experiment with a gamma camera with the outcomes from a Monte Carlo simulation of the same experimental apparatus. We employed a 99m Tc source emitting 140.5keV photons, collimated in the upper direction through two pinholes, shielded by 6mm of lead. An aluminium cylinder was placed on the source at 50mm of distance. The energy of the scattered photons was measured on the spectra acquired by the gamma camera. We observed that the gamma ray energy measured at each step of rotation gradually decreased from the characteristic energy of 140.5keV at 0° to 102.5keV at 120°. A comparison between the obtained data and the expected results from the Compton formula and from the Monte Carlo simulation revealed a full agreement within the experimental error (relative errors between -0.56% and 1.19%), given by the energy resolution of the gamma camera. Also the electron rest mass has been evaluated satisfactorily. The experiment was found useful in explaining nuclear medicine residents the phenomenology of the Compton scattering and its importance in the nuclear medicine imaging, and it can be profitably proposed during the training of medical physics residents as well. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Preparation of cobra (Naja naja) venom toxoid using gamma-radiations. Part I

International Nuclear Information System (INIS)

Gaitonde, B.B.; Kankonkar, S.R.

1975-01-01

Detoxification of venom by radiation was investigated. Two concentrations i.e. 0.01% of venom solution were irradiated with different doses of gamma-radiations from cobalt-60 source. The results obtained indicate that the toxicity of venom is markedly attenuated by gamma-radiation. (author)

Measurement of gamma radiation doses in nuclear power plant environment

International Nuclear Information System (INIS)

Bochvar, I.A.; Keirim-Markus, I.B.; Sergeeva, N.A.

1976-01-01

Considered are the problems of measuring gamma radiation dose values and the dose distribution in the nuclear power plant area with the aim of estimating the extent of their effect on the population. Presented are the dosimeters applied, their distribution throughout the controlled area, time of measurement. The distribution of gamma radiation doses over the controlled area and the dose alteration with the increase of the distance from the release source are shown. The results of measurements are investigated. The conclusion is made that operating nuclear power plants do not cause any increase in the gamma radiation dose over the area. Recommendations for clarifying the techniques for using dose-meters and decreasing measurement errors are given [ru

X-ray and. gamma. -ray sources: a comparison of their characteristics

Energy Technology Data Exchange (ETDEWEB)

Freund, A K [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)

1979-11-01

A comparison of the various source characteristics, in particular the available fluxes of radiation in the X-ray/..gamma..-ray region from (1) high power rotary anode X-ray generators, (2) radioactive ..gamma..-ray sources and (3) high energy electron storage rings is presented. Some of the specific characteristics and possible applications of synchrotron radiation as a source are discussed in detail, together with problems associated with the monochromatization of the continuous radiation in the X-ray/..gamma..-ray region. The new high energy machines PEP at Stanford, the 8 GeV storage ring CESR at Cornell and the PETRA storage ring in Hamburg, which will soon come into operation provide a spectrum of high intensity radiation reaching well above h..gamma..sub(photon)=100 keV. The possibilities of using ondulators (wigglers), and laser-electron scattering for constructing high repetition rate tunable ..gamma..-ray sources are also discussed. Finally the potentials of using the powerful spontaneous emission of ..gamma..-quanta by relativistic channeled particles are mentioned.

The selection of radiation tolerant electrical/electronic components for gamma radiation environments in the nuclear power industry

International Nuclear Information System (INIS)

Garlick, D.R.

1984-09-01

This report briefly describes the mechanisms, units and effects of 1 MeV range gamma radiation on electrical/electronic components and materials. Information is tabulated on the gamma radiation tolerance of a wide range of components and materials. A radiation testing service, based at Harwell, is described. Lists of interested manufacturers and organisations are given. (author)

Sewage sterilization through gamma radiation

International Nuclear Information System (INIS)

Vieira, D.V.; Teixeira, W.M.S.; Silva, F.C.A. da

2017-01-01

Lack of sewage treatment and adequate sanitation conditions can contribute to the proliferation of numerous parasitic and infectious diseases in addition to water degradation. Approximately fifty types of infections can be transmitted from a sick to a healthy person through different pathways involving human excreta. Untreated sewage can contaminate water, food, hands, soil, etc. Epidemics of certain diseases such as typhoid, cholera, dysenteries, etc., and countless cases of worms are responsible for high mortality rates in third world countries. In the work the different techniques of sewage treatment by disinfestation and sterilization were analyzed, highlighting the use and the advantages of the gamma radiation as well as the aspects of the radiological protection involved. The technique of sewage sterilization using gamma radiation is a method of controlling bacteria and microorganisms. It is estimated that more than 200 large irradiators are in operation worldwide, of which 5 are in Brazil, for general sterilization use. These facilities use a large amount of radioactive material, in the order of millions of Becquerel, for sterilization with high doses of radiation, which can generate lethal doses in a few minutes. These industrial facilities use Cobalt-60, being classified by the International Atomic Energy Agency - IAEA as Category 1 of high risk, and must possess a high level of radiological protection to carry out the sterilization, standing out the defense in depth. Specific legislation on radiological protection should be drafted for safe work and avoid future radiation accidents

Uranium measurement by airborne gamma-ray spectrometry

International Nuclear Information System (INIS)

Grasty, R.L.

1975-01-01

In the airborne measurement of uranium, window type gamma-ray spectrometers are used and it is necessary to correct for scattered high energy radiation from thallium 208 in the thorium decay series. This radiation can be scattered in the crystal, in the ground, and in the air. A theory, analogous to the theory of radioactive decay, is developed; it can adequately explain the spectrum buildup in the uranium window for a point source of thorium oxide immersed to different depths in water and for a detector above the water. The theory is extended to predict the buildup as a function of altitude for detectors of different sizes and shows that errors in the airborne measurement of uranium can be significant if no allowance is made for radiation scattered in the ground and in the air

Gamma radiation in apartments

International Nuclear Information System (INIS)

Grindborg, J.-E.

1983-05-01

This investigation forms the basis for the description of methods for the detection of gamma radiation. The aim is to control that the dose limit will not exceed 50 μR/h in a room where people reside. The distribution of dose rates in different rooms has been calculated and the results have been compared with experimental data. Various instruments have been calibrated and their specifications are discussed. (G.B.)

Application of the Radiative Transfer Equation (RTE) to Scattering by ...

African Journals Online (AJOL)

Application of the Radiative Transfer Equation (RTE) to Scattering by a Dust Aerosol Layer. ... Incident radiation in its journey through the atmosphere before reaching the earth surface encounters particles of different sizes and composition such as dust aerosols resulting in interactions that lead to absorption and scattering.

Gamma radiation effects on physical properties of parchment documents: Assessment of Dmax

International Nuclear Information System (INIS)

Nunes, Inês; Mesquita, Nuno; Cabo Verde, Sandra; João Trigo, Maria; Ferreira, Armando; Manuela Carolino, Maria; Portugal, António; Luísa Botelho, Maria

2012-01-01

Parchments are important documents that give testimony for History; therefore these materials should be respected and preserved. Considering incremental biodeterioration problems that have to be faced daily, the Archive of the University of Coimbra (AUC) is involved in different scientific projects in order to evaluate and determine new methods for document decontamination and preservation. The aim of this study was to evaluate gamma radiation effects on the colour and texture of the AUC parchment documents. The assessment of these effects was used to estimate the maximum gamma radiation dose (D max ) that could guarantee parchment documents′ decontamination treatment, without significant alteration of their physical properties. Parchment samples were exposed to gamma radiation doses ranging from 10 to 30 kGy. The texture and colour of samples were assessed before and after the irradiation procedure, using a texture analyser and an electronic colorimeter. Hardness and springiness were determined based on texture spectra. Lightness (L⁎), Chroma (C), greenness vs. redness (a*) and yellowness vs. blueness (b*) values were obtained from colorimetric measures. Results indicate no significant effects of gamma radiation on the texture and colour of parchment for the studied doses. - Highlights: ► Study on the effects of gamma radiation in parchment physical properties. ► Evaluation of the uniformity of parchment samples′ physical parameters. ► Proposal of a maximum gamma radiation dose for parchment decontamination treatment.

Gamma radiation effects on polydimethylsiloxane rubber foams under different radiation conditions

Science.gov (United States)

Sui, H. L.; Liu, X. Y.; Zhong, F. C.; Li, X. Y.; Wang, L.; Ju, X.

2013-07-01

Polydimethylsiloxane rubber foams were irradiated by gamma ray under different radiation conditions designed by orthogonal design method. Compression set measurement, infrared attenuated total reflectance spectroscopy (ATR) and X-ray induced photoelectron spectroscopy (XPS) were used. Three aging factors' influence effects on the mechanical property and chemical structure were studied. It was found that among the three factors and the chosen levels, both properties were affected most by radiation dose, while radiation dose rate had no obvious influence on both properties. The stiffening of the rubber foams was caused by cross-linking reactions in the Si-CH3. At the same radiation dose, the rigidity of the foams irradiated in air was lower than that in nitrogen. When polydimethylsiloxane was irradiated at a high dose in sealed nitrogen atmosphere, carbon element distribution would be changed. Hydrocarbons produced by gamma ray in the sealed tube would make the carbon content in the skin-deep higher than that in the middle, which indicated that polydimethylsiloxane rubber foams storing in a sealed atmosphere filled with enough hydrocarbons should be helpful to extend the service life.

Gamma radiation effects on polydimethylsiloxane rubber foams under different radiation conditions

Energy Technology Data Exchange (ETDEWEB)

Sui, H.L. [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China); Institute of Chemical Materials, CAEP, Mianyang 621900 (China); Liu, X.Y.; Zhong, F.C. [Institute of Chemical Materials, CAEP, Mianyang 621900 (China); Li, X.Y. [Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900 (China); Wang, L. [Institute of Chemical Materials, CAEP, Mianyang 621900 (China); Ju, X., E-mail: jux@ustb.edu.cn [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China)

2013-07-15

Polydimethylsiloxane rubber foams were irradiated by gamma ray under different radiation conditions designed by orthogonal design method. Compression set measurement, infrared attenuated total reflectance spectroscopy (ATR) and X-ray induced photoelectron spectroscopy (XPS) were used. Three aging factors’ influence effects on the mechanical property and chemical structure were studied. It was found that among the three factors and the chosen levels, both properties were affected most by radiation dose, while radiation dose rate had no obvious influence on both properties. The stiffening of the rubber foams was caused by cross-linking reactions in the Si–CH{sub 3}. At the same radiation dose, the rigidity of the foams irradiated in air was lower than that in nitrogen. When polydimethylsiloxane was irradiated at a high dose in sealed nitrogen atmosphere, carbon element distribution would be changed. Hydrocarbons produced by gamma ray in the sealed tube would make the carbon content in the skin-deep higher than that in the middle, which indicated that polydimethylsiloxane rubber foams storing in a sealed atmosphere filled with enough hydrocarbons should be helpful to extend the service life.

Gamma radiation of quartz from Entre Rios (SC) and QuaraÍ (RS)

International Nuclear Information System (INIS)

Enokihara, Cyro T.; Rela, Paulo R.; Schultz-Güttler, Rainer A.

2017-01-01

The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with many colored commercial varieties. A specific variety of quartz showing a green color in nature or induced artificially by radiation gamma ( 60 Co) is quite rare. In Brazil the widely scattered geode occurrences along a 600 km stretch from Quaraí at Brazil southernmost tip to Uberlandia in Minas Gerais is one of these. Quartz from these occurrences have been formed by strong hydrothermal activities. That way much quartz crystals showed a very fast growth history facilitating the formation of growth defects and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work the material analyzed is from hydrothermal regimes located near the towns Entre Rios (SC) and Quaraí (RS). To characterize these materials analyses have been made by ICP, NAA, electron microscopy, water loss techniques and UV-VIS and NIR-FTIR spectroscopic measurements. Silanol complexes are found, which by radiation due to gamma rays form the color center NBOHC (Non-Bonding Oxygen Hole Center), showing absorption between 590 to 620 nm and leaving a transmission window at about 550nm, responsible for the green color. The spectroscopic water determination showed less molecular water (up to 2300 ppm by weight), probably due to remaining silanol complexes.The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li). (author)

Gamma radiation of quartz from Entre Rios (SC) and QuaraÍ (RS)

Energy Technology Data Exchange (ETDEWEB)

Enokihara, Cyro T.; Rela, Paulo R., E-mail: cteiti@ipen.br, E-mail: prela06@yahoo.com.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Schultz-Güttler, Rainer A., E-mail: rainersgut@gmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Geociências

2017-07-01

The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with many colored commercial varieties. A specific variety of quartz showing a green color in nature or induced artificially by radiation gamma ({sup 60}Co) is quite rare. In Brazil the widely scattered geode occurrences along a 600 km stretch from Quaraí at Brazil southernmost tip to Uberlandia in Minas Gerais is one of these. Quartz from these occurrences have been formed by strong hydrothermal activities. That way much quartz crystals showed a very fast growth history facilitating the formation of growth defects and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work the material analyzed is from hydrothermal regimes located near the towns Entre Rios (SC) and Quaraí (RS). To characterize these materials analyses have been made by ICP, NAA, electron microscopy, water loss techniques and UV-VIS and NIR-FTIR spectroscopic measurements. Silanol complexes are found, which by radiation due to gamma rays form the color center NBOHC (Non-Bonding Oxygen Hole Center), showing absorption between 590 to 620 nm and leaving a transmission window at about 550nm, responsible for the green color. The spectroscopic water determination showed less molecular water (up to 2300 ppm by weight), probably due to remaining silanol complexes.The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li). (author)

Resistance of Salmonella enteritidis variety typhimurium to gamma radiation

International Nuclear Information System (INIS)

Norberg, A.N.; Maliska, C.

1988-01-01

The use of ionizing radiations to kill microrganisms responsible for food deterioration, and toxinfections is an example of peaceful use of nuclear energy. Food toxinfections are, amongus, produced mostly by Salmonella enteritidis var. typhimurium. Due to the pauncity of information on the resistance to gamma radiation of Salmonella enteritidis var. typhimurium this paper has the aim to define the 60-Cobalt gamma radiation lethal dose to these bacteria, in experimentally contaminated milk by samples recovered from our geographycal area. One hundred nineteen samples of milk containing about 150.000 bacteria per ml were irradiated with doses ranging from 100 to 1.100 Gy. Two samples of surving bacteria were again irradiated by doses up to 2.500 Gy. The bacteria not previously irradiated were killed by doses of 1.100 Gy. It was concluded that the 60-Cobalt gamma radiation minimal lethal dose to Salmonella enteritidis var. typhimurium is 1.200 Gy. The surviving strains to smaller doses than 1.200 Gy when re-irradiated prompt the forthcoming of more radio-resistant germs. (author) [pt

Calculation of gamma-ray flux density above the Venus and Earth surfaces

International Nuclear Information System (INIS)

Surkov, Yu.A.; Manvelyan, O.S.

1987-01-01

Calculational results of dependence of flux density of nonscattered gamma-quanta on the height above the Venus and Earth planet surfaces are presented in the paper. Areas, where a certain part of gamma quanta is accumulated, are calaculted for each height. Spectra of scattered gamma quanta and their integral fluxes at different heights above the Venera planet surface are calculated. Effect of the atmosphere on gamma radiation recorded is considered. The results obtained allow to estimate optimal conditions for measuring gamma-fields above the Venus and Earth planet surfaces, to determine the area of the planet surface investigated. They are also necessary to determine the elementary composition of the rock according to the characteristic gamma radiation spectrum recorded

Effects of gamma radiation in cauliflower (Brassica spp) minimally processed

International Nuclear Information System (INIS)

Nunes, Thaise C.F.; Rogovschi, Vladimir D.; Thomaz, Fernanda S.; Trindade, Reginaldo A.; Villavicencio, Anna L.C.H.; Alencar, Severino M.

2007-01-01

Consumers demand for health interests and the latest diet trends. The consumption of vegetables worldwide has increased every year over the past decade, consequently, less extreme treatments or additives are being required. Minimally processed foods have fresh-like characteristics and satisfy the new consumer demand. Food irradiation is an exposure process of the product to controlled sources of gamma radiation with the intention to destroy pathogens and to extend the shelf life. Minimally processed cauliflower (Brassica oleraceae) exposed to low dose of gamma radiation does not show any change in sensory attributes. The aim of this study was to analyze the effects of the low doses of gamma radiation on sensorial aspects like appearance, texture and flavor of minimally processed cauliflower. (author)

Effect of gamma-radiation on a water-insoluble arabinoxylan

International Nuclear Information System (INIS)

Ebringerová, A.; Pružinec, J.; Kačuráková, M.; Hromádková, Z.

1989-01-01

The effect of gamma radiation on a water-insoluble L-arabino-D-xylan has been studied by functional group and structural analysis using chemical methods and IR spectroscopy, by sugar composition analysis, and by viscosity measurements. The gamma irradiation has been shown to modify both sugar components of the arabinoxylan, accompanied by cleavage of the glycosidic linkages, depolymerization, and sugar decomposition, depending on the applied radiation dose, thus increasing the molecular and chemical heterogeneity of the polysaccharide. (author)

Insect disinfestation of packed dates by gamma-radiation

International Nuclear Information System (INIS)

Ahmed, M.S.H.; Hameed, A.A.; Kadhum, A.A.; Ali, S.R.

1985-01-01

The effect of gamma-radiation on insect disinfestation of commercially packed dry dates was studied in collaboration with the Iraqui Date Administration. The wrapping of ''window carton lunch boxes'' (each holding 250 g of dry dates, Zahdi variety) with polyethylene film, compared to cellophane, prevented reinfestation for a long period of storage if treated with 0.70 kGy of gamma-radiation. All live insects that were found in the irradiated boxes and tested were genetically sterile, and those in different developmental stages died within a short period of time without passing through metamorphosis. In all cases (treated or control batches), cellophane-sealed boxes proved to be more vulnerable to reinfestation. Dates packed in plastic cups, used for N/sub 2/ vacuum packaging, were also effectively disinfested by the same dose of radiation. The value of airtight packaging will certainly add to the advantage of the high penetration power of gamma-radiation relative to methyl bromide fumigation. Results of the assessment of the damaging ability of irradiated insects indicate that treatment of packed dates with 0.70 kGy is sufficient as far as quarantine measures are concerned where the possible increase in infestation rate, brought about by radio-resistant insect stages that usually constitute a small fraction in nature, is negligible

Gamma radiation detectors for safeguards applications

International Nuclear Information System (INIS)

Carchon, R.; Moeslinger, M.; Bourva, L.; Bass, C.; Zendel, M.

2007-01-01

The IAEA uses extensively a variety of gamma radiation detectors to verify nuclear material. These detectors are part of standardized spectrometry systems: germanium detectors for High-Resolution Gamma Spectrometry (HRGS); Cadmium Zinc Telluride (CZT) detectors for Room Temperature Gamma Spectrometry (RTGS); and NaI(Tl) detectors for Low Resolution Gamma Spectrometry (LRGS). HRGS with high-purity Germanium (HpGe) detectors cooled by liquid nitrogen is widely used in nuclear safeguards to verify the isotopic composition of plutonium or uranium in non-irradiated material. Alternative cooling systems have been evaluated and electrically cooled HpGe detectors show a potential added value, especially for unattended measurements. The spectrometric performance of CZT detectors, their robustness and simplicity are key to the successful verification of irradiated materials. Further development, such as limiting the charge trapping effects in CZT to provide improved sensitivity and energy resolution are discussed. NaI(Tl) detectors have many applications-specifically in hand-held radioisotope identification devices (RID) which are used to detect the presence of radioactive material where a lower resolution is sufficient, as they benefit from a generally higher sensitivity. The Agency is also continuously involved in the review and evaluation of new and emerging technologies in the field of radiation detection such as: Peltier-cooled CdTe detectors; semiconductor detectors operating at room temperature such as HgI 2 and GaAs; and, scintillator detectors using glass fibres or LaBr 3 . A final conclusion, proposing recommendations for future action, is made

Radiation-mediated Shocks in Gamma-Ray Bursts: Pair Creation

Science.gov (United States)

Lundman, Christoffer; Beloborodov, Andrei M.; Vurm, Indrek

2018-05-01

Relativistic sub-photospheric shocks are a possible mechanism for producing prompt gamma-ray burst (GRB) emission. Such shocks are mediated by scattering of radiation. We introduce a time-dependent, special relativistic code which dynamically couples Monte Carlo radiative transfer to the flow hydrodynamics. The code also self-consistently follows electron–positron pair production in photon–photon collisions. We use the code to simulate shocks with properties relevant to GRBs. We focus on plane-parallel solutions, which are accurate deep below the photosphere. The shock generates a power-law photon spectrum through the first-order Fermi mechanism, extending upward from the typical upstream photon energy. Strong (high Mach number) shocks produce rising νF ν spectra. We observe that in non-relativistic shocks the spectrum extends to {E}\\max ∼ {m}e{v}2, where v is the speed difference between the upstream and downstream. In relativistic shocks the spectrum extends to energies E> 0.1 {m}e{c}2 where its slope softens due to Klein–Nishina effects. Shocks with Lorentz factors γ > 1.5 are prolific producers of electron–positron pairs, yielding hundreds of pairs per proton. The main effect of pairs is to reduce the shock width by a factor of ∼ {Z}+/- -1. Most pairs annihilate far downstream of the shock, and the radiation spectrum relaxes to a Wien distribution, reaching equilibrium with the plasma at a temperature determined by the shock jump conditions and the photon number per proton. We discuss the implications of our results for observations of radiation generated by sub-photospheric shocks.

Gamma radiation effects on vitamin C standard solutions

International Nuclear Information System (INIS)

Amaro, Jose Daniel V.; Mansur Netto, Elias

1995-01-01

This word shows the physical - chemical effects of gamma radiation on standard solutions of vitamin C. Samples with concentration of 50 mg/ml were exposed to different doses of gamma radiations: 1,0 2,5 and 5,0 kGy, using a cobalt-60 source, with storing periods of 0,15 and 30 days. The results showed a vitamin C concentration loss, with a minimum of 17% for the dose of 1,0 kGy immediately after irradiation and a maximum of 81% for the dose of 5 kGy and 30 days after irradiation. (author). 3 refs., 2 tabs

Study of local Agregate for Gamma radiation concrete shield

International Nuclear Information System (INIS)

Tochrul-Binowo; Endro-Kismolo; Darsono

1996-01-01

Investigation on the composition of gamma radiation concrete shield made of local barite, manganese fine and coarse aggregates from Kulon Progo, Yogyakarta has been done. The purpose of the research was to find out the quality of these local material for an aggregate of gamma radiation concrete shield. The research was done where each mineral was used as coarse aggregate and the fine aggregate from Kulon Progo was used as fine basic aggregate. Firstly a normal concrete was made by mixing cement, fine aggregate, coarse aggregate and water at a weight ratio of cement: fine aggregate: coarse: water 1: 2.304: 3.456: 0.58. The gamma radiation absorption capacity of the concrete tested by using Cs-137 as source standard. The same method was done on barite concrete at the weight ratio of cement: fine aggregate: barite aggregate: water 1: 2.303: 3.456: 0.58 and manganese concrete at the weight ratio of cement: fine aggregate: manganese aggregate: and water 1: 1.896: 2.844: 0.58. The result of the study showed that the gamma radiation absorption capacity of barite aggregate was greater than that of normal concrete and manganese concrete. The coefficient linear attenuation (for 6.0 cm thickness) of each concrete were μ barite concrete = 0.23071 cm -1 , μ manganese concrete = 0.08401 cm -1 and μ normal concrete = 0.1669 cm -1

Characterization of TL dosimeters for determination of the gamma component in a mixed n+γ radiation field

International Nuclear Information System (INIS)

Ranogajec-Komor, M.; Miljanic, S.; Ferek, S.; Dvornik, I.; Osvay, M.

1996-01-01

In the International Intercomparison of the Criticality Accident Dosimetry Systems organized by the Commission of European Communities at SILENE Reactor in Valduc, France, 1993, the Ruder Boskovic Institute (RBI) measured the total neutron and gamma tissue absorbed dose (D n+γ ) at the body surface irrespective of neutron and gamma energy spectra variations using the chemical dosimeters DL-M4. For deriving the neutron dose i.e recoil dose, D n , from the differences D n = D n+γ - D t , the total gamma dose (D tγ ) has to be measured with highest accuracy. The determination of the gamma dose in a mixed field is complicated because TL dosimeters are sensitive both to neutrons and gammas. Besides, the radiation doses and energy spectra vary because of scattering and absorption in the body or phantom. Therefore dosimeters with different sensitivities, energy dependences and encapsulations have to be used. In this paper only the study of some characteristics of various TL detectors, such as sensitivity, linearity, supralinearity and fading, for measurement of the gamma component are described. These investigations were carried out in RBI before and after the Valduc intercomparison experiments. The encapsulations, TL response corrections for thermal and fast neutron effects as well as the discussion of Valduc results will be published later

Prompt Gamma Radiation from Fragments in the Thermal Fission of {sup 235}U

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goteborg (Sweden); Lindow, L [AB Atomenergi, Nykoeping (Sweden)

1970-06-15

Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of {sup 235}U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from {sup 252} Cf-fission. Attention is drawn to some features which seem to be the same in {sup 235}U and {sup 252} Cf-fission.

Variation of Neutron Moderating Power on HDPE by Gamma Radiation

International Nuclear Information System (INIS)

Park, Kwang June; Ju, June Sik; Kang, Hee Young; Shin, Hee Sung; Kim, Ho Dong

2009-01-01

High density polyethylene (HDPE) is degraded due to a radiation-induced oxidation when it is used as a neutron moderator in a neutron counter for a nuclear material accounting of spent fuels. The HDPE exposed to the gamma-ray emitted from the fission products in a spent nuclear fuel results in a radiation-induced degradation which changes its original molecular structure to others. So a neutron moderating power variation of HDPE, irradiated by a gamma radiation, was investigated in this work. Five HDPE moderator structures were exposed to the gamma radiation emitted from a 60 Co source to a level of 10 5 -10 9 rad to compare their post-irradiation properties. As a result of the neutron measurement test with 5 irradiated HDPE structures and a neutron measuring system, it was confirmed that the neutron moderating power for the 105 rad irradiated HDPE moderator revealed the largest decrease when the un-irradiated pure one was used as a reference. It implies that a neutron moderating power variation of HDPE is not directly proportional to the integrated gamma dose rate. To clarify the cause of these changes, some techniques such as a FTIR, an element analysis and a densitometry were employed. As a result of these analyses, it was confirmed that the molecular structure of the gamma irradiated HDPEs had partially changed to others, and the contents of hydrogen and oxygen had varied during the process of a radiation-induced degradation. The mechanism of these changes cannot be explained in detail at present, and thus need further study

Development of a Compact Gamma-ray Detector for a Neural-Network Radiation Monitoring

Energy Technology Data Exchange (ETDEWEB)

Kim, H. S.; Ha, J. H.; Lee, K. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, C. H. [Hanyang Univ., Seoul (Korea, Republic of)

2012-03-15

Radiation monitoring is very important to secure safety in nuclear-related facilities and against nuclear terrorism. For wide range of radiation monitoring, neutral network system of radiation detection is most efficient way. Thus, a compact radiation detector is useful to install in wide range to be concerned. A compact gamma-ray detector was fabricated by using a CsI(Tl) scintillator, which was matched with the formerly developed PIN photodiode, for a neural network radiation monitoring. At room temperature, the fabricated compact gamma-ray detector demonstrates an energy resolution of 13.3 % for 662 keV 6.9% for 1330 keV. The compactness, the low-voltage power consumption and the physical hardness are very useful features for a neural network radiation monitoring. In this study, characteristics of a fabricated compact gamma-ray detector were presented. An important aspect to consider in a neural-network radiation monitoring such as reaction probability of the fabricated compact detector for angle of incident gamma-ray was also addressed.

Concrete for. gamma. radiation shielding

Energy Technology Data Exchange (ETDEWEB)

de Azevedo e Souza, A.C. (Rio de Janeiro Univ. (Brazil). Inst. de Quimica); Rogers, J D [Rio de Janeiro Univ. (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

1980-06-01

The attenuation characteristics of ..gamma.. radiation in concrete slabs, considering their mechanical resistence and densities were determined. One heavy concrete which was used, was prepared using as additives iron ore and Fe/sub 2/ O/sub 3/ pellets in various grain sizes. Fortran programs were used for analysing data and determining the absorption coefficients and attenuation factors.

Reduction of the scattered radiation during X-ray examination with screen-film systems

Energy Technology Data Exchange (ETDEWEB)

Vasiliev, V N; Stavitsky, R V [Moscow Research Inst. for Roentgenology and Radiology, Moscow (Russian Federation); Oshomkov, Yu V [Mosroentgen, Moscow Region (Russian Federation)

1993-01-01

In diagnostic radiography, during X-ray examination, photons scattered in the patient's body are detected by the intensifying screen and decrease the image contrast. A conventional way to avoid this image degradation is to attenuate the scattered radiation by an antiscatter grid placed between the patient's body and the screen. A grid selectivity effect originates from the greater attenuation of scattered as opposed to primary radiation. Previous authors calculated the primary and scattered radiation transmission factor of photons with initial energy 30-120 keV for a number of typical grids. The primary radiation transmission factor varied from 0.34 to 0.67 and the secondary radiation factor was equal from 0.03 to 0.13. This effect results in a contrast improvement from 2 to 6, but the patient exposure increases up to a factor of 10. In this work we studied the possibility of improving the image contrast by attenuating the scattered radiation by a secondary filter placed between the patient's body and the screen and made of an appropriate material. A selectivity effect due to the secondary filter arises from two circumstances. First, tilting incidence of the scattered radiation results in the path inside the filter being greater than the primary one. Second, the average energy of the scattered radiation is less than the primary and, hence, the attenuation coefficient is greater. (author).

Characterization of crumb rubber modified by gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Faldini, Sonia B.; Terence, Mauro C.; Miranda, Leila F.; Munhoz, Antonio H.; Domingues, Leandro S.; Coghetto, Gregory, E-mail: sfaldini@yahoo.com.br, E-mail: mauroterence@yahoo.com.br [Universidade Presbiteriana Mackenzie (UPM), Sao Paulo, SP (Brazil). Escola de Engenharia. Engenharia de Materiais

2013-07-01

The use of crumb rubber from scrap tires has become a common practice in the construction of roads, leading to improved properties of the asphalt and decreasing the environmental pollution. In this study, crumb rubber was modified by gamma radiation to eventually incorporate it into the asphalt and verify potential improvements of their properties. The crumb rubber modified by gamma radiation in the dose 500 kGy and 1000kGy was characterized by thermal analysis, infrared spectroscopy and scanning electron microscopy. The dose of radiation used has no effect on degradation temperatures. It is observed that the IV spectra of untreated rubbers and rubbers irradiated have substantially the same profile. The results indicate that despite small morphological changes in the irradiated rubber, they do not influence its degradation temperature and composition. (author)

Characterization of crumb rubber modified by gamma radiation

International Nuclear Information System (INIS)

Faldini, Sonia B.; Terence, Mauro C.; Miranda, Leila F.; Munhoz, Antonio H.; Domingues, Leandro S.; Coghetto, Gregory

2013-01-01

The use of crumb rubber from scrap tires has become a common practice in the construction of roads, leading to improved properties of the asphalt and decreasing the environmental pollution. In this study, crumb rubber was modified by gamma radiation to eventually incorporate it into the asphalt and verify potential improvements of their properties. The crumb rubber modified by gamma radiation in the dose 500 kGy and 1000kGy was characterized by thermal analysis, infrared spectroscopy and scanning electron microscopy. The dose of radiation used has no effect on degradation temperatures. It is observed that the IV spectra of untreated rubbers and rubbers irradiated have substantially the same profile. The results indicate that despite small morphological changes in the irradiated rubber, they do not influence its degradation temperature and composition. (author)

Observations of nesting avifauna under gamma-radiation exposure

International Nuclear Information System (INIS)

Buech, R.R.

1977-01-01

An opportunity arose to observe the nesting success of birds (up to the time of fledging) when the Enterprise Forest Radiation Facility was established for a study of the effects of gamma radiation on the flora and fauna of northern forest communities. The results of these observations on the fate of the nest occupants in relation to radiation exposure are presented

Galactic structure and gamma radiation

International Nuclear Information System (INIS)

Casse, Michel; Cesarsky, Catherine; Paul Jacques

1977-01-01

A model of spiral structure of the Galaxy is outlined from radiosynchrotron and gamma observations. The most interesting observations in the galactic context, obtained by the SAS II American satellite are concerned with the distribution of the γ photoemission at energies higher than 10 8 eV, along the galactic equator. The model proposed is in quantitative agreement with the present ideas on the spiral structure of the Galaxy, the galactic magnetic field, and the confinement of cosmic rays by the magnetic field and of the magnetic field by matter. Following the American era, the European COS-B satellite opens the European phase towards an identification of the discrete gamma radiation sources [fr

Combined effect of gamma radiation and stress cracking in polystyrene

International Nuclear Information System (INIS)

Amorim, Fernando A.; Rabello, Marcelo S.; Silva, Leonardo G.A.

2011-01-01

This study aimed to evaluate the combined effect of gamma radiation and stress cracking in polystyrene. Three different grades of polystyrene were analysed. The material was submitted to tensile tests and relaxation, analysis of molecular weight and determination of crosslinking. The results showed an increase in tensile strength in the specimens that had been exposed to radiation. The higher the molecular weight polystyrene showed better mechanical properties and after suffering the effects of gamma radiation there was an increase of 5.67% in the resistance to stress cracking effects. (author)

Gamma radiation combined with cinnamon oil to maintain fish quality

Science.gov (United States)

Lyu, Fei; Zhang, Jing; Wei, Qianqian; Gao, Fei; Ding, Yuting; Liu, Shulai

2017-12-01

Effects of gamma radiation combined with cinnamon oil on quality of Northern Snakehead fish fillets were observed during storage at 4 °C. Fish fillets were treated with 1-5 kGy gamma radiation, 0.05-0.5% cinnamon oil or the combination of radiation and cinnamon oil. The antimicrobial activity increased with radiation dose and cinnamon oil concentration. During storage, the combination of 1 kGy radiation and 0.5% cinnamon oil displayed better inhibiting activities on aerobic plate counts, total volatile basic nitrogen, thiobarbituric acid reaction substances than 1 kGy radiation or 0.5% cinnamon oil used alone. Moreover, the combination could arrive at the similar inhibiting activities of cinnamon oil with higher concentration of 0.5% or radiation with higher dose of 5 kGy. Thus, the combination could decrease the radiation dose and cinnamon oil concentration without decreasing the effect of them on maintaining fish quality.

Compton scattering study of electron momentum distribution in lithium fluoride using 662 keV gamma radiations

Science.gov (United States)

Vijayakumar, R.; Shivaramu; Ramamurthy, N.; Ford, M. J.

2008-12-01

Here we report the first ever 137Cs Compton spectroscopy study of lithium fluoride. The spherical average Compton profiles of lithium fluoride are deduced from Compton scattering measurements on poly crystalline sample at gamma ray energy of 662 keV. To compare the experimental data, we have computed the spherical average Compton profiles using self-consistent Hartree-Fock wave functions employed on linear combination of atomic orbital (HF-LCAO) approximation. The directional Compton profiles and their anisotropic effects are also calculated using the same HF-LCAO approximation. The experimental spherical average profiles are found to be in good agreement with the corresponding HF-LCAO calculations and in qualitative agreement with Hartree-Fock free atom values. The present experimental isotropic and calculated directional profiles are also compared with the available experimental isotropic and directional Compton profiles using 59.54 and 159 keV γ-rays.

Scatter radiation exposure during knee arthrography

International Nuclear Information System (INIS)

Light, M.C.; Molloi, S.Y.; Yandow, D.R.; Ranallo, F.N.

1987-01-01

Knee arthrography, as performed at the authors' institution, was simulated and scattered radiation exposure to a radiologist's gonads, thyroid, and eye lens was measured with a sensitive ionization chamber. Results show that radiologists who regularly conduct knee arthrography examinations can incur doses to the gonads that are less than 6% of the U.S. limits, and to the thyroid and eye that are approximately 10% of the U.S. limits. Since the scatter radiation from overhead imaging of stress views constituted most (greater than or equal to 60%) of the dose to the lens of the eye and the thyroid, spot imaging was evaluated as a substitute for overhead imaging in the assessment of the anterior cruciate ligament. This substitution resulted in no loss of clinical information and has now completely replaced overhead imaging of stress views at this institution

Thomson scattering if FIR radiation

International Nuclear Information System (INIS)

Evans, D.E.

1976-12-01

The frequency spectrum of radiation scattered by collective density fluctuations of electrons in a hot plasma is influenced by ion and electron temperatures, impurity concentration and plasma effective charge, magnetic field, and the level of microturbulence. A pulsed laser suitable for measuring collective scattering in a tokamak will have infrared wavelength, power of the order of MWs and bandwidth of a few 10s of MHz. The extent to which these conditions can be met by optically pumped submillimetre lasers, including narrow band oscillators, amplifiers and superradiance - injection assemblies operated in CH 3 F and D 2 O, under development at the Culham Laboratory, is discussed. (author)

Effects of Scattering of Radiation on Wormholes

Directory of Open Access Journals (Sweden)

Alexander Kirillov

2018-02-01

Full Text Available Significant progress in the development of observational techniques gives us the hope to directly observe cosmological wormholes. We have collected basic effects produced by the scattering of radiation on wormholes, which can be used in observations. These are the additional topological damping of cosmic rays, the generation of a diffuse background around any discrete source, the generation of an interference picture, and distortion of the cosmic microwave background (CMB spectrum. It turns out that wormholes in the leading order mimic perfectly analogous effects of the scattering of radiation on the standard matter (dust, hot electron gas, etc.. However, in higher orders, a small difference appears, which allows for disentangling effects of wormholes and ordinary matter.

Papain incorporated chitin dressings for wound debridement sterilized by gamma radiation

International Nuclear Information System (INIS)

Singh, Durgeshwer; Singh, Rita

2012-01-01

Wound debridement is essential for the removal of necrotic or nonviable tissue from the wound surface to create an environment conducive to healing. Nonsurgical enzymatic debridement is an attractive method due to its effectiveness and ease of use. Papain is a proteolytic enzyme derived from the fruit of Carica papaya and is capable of breaking down a variety of necrotic tissue substrates. The present study was focused on the use of gamma radiation for sterilization of papain dressing with wound debriding activity. Membranes with papain were prepared using 0.5% chitin in lithium chloride/dimethylacetamide solvent and sterilized by gamma radiation. Fluid absorption capacity of chitin–papain membranes without glycerol was 14.30±6.57% in 6 h. Incorporation of glycerol resulted in significant (p 2 /24 h at 24 h. Gamma irradiation at 25 kGy was found suitable for sterilization of the dressings. Infrared (IR) spectral scanning has shown that papain was stable on gamma irradiation at 25–35 kGy. The irradiated chitin–papain membranes were impermeable to different bacterial strains and also exhibited strong bactericidal action against both Gram-positive and Gram-negative bacteria. The fluid handling characteristics and the antimicrobial properties of chitin–papain membranes sterilized by gamma radiation were found suitable for use as wound dressing with debriding activity. - Highlight: ► Use of gamma radiation for sterilization of papain wound dressing was studied. ► Fluid handling and antimicrobial properties of irradiated dressings was evaluated. ► Gamma irradiation at 25 kGy was found suitable for sterilization of the dressings.

Comparison of gamma radiation - induced effects in two human prostate cancer cells

International Nuclear Information System (INIS)

Vucic, V.; Adzic, M.; Ruzdijic, S.; Radojcic, M.B. . E-mail address of corresponding author: vesnav@vin.bg.ac.yu; Vucic, V.)

2005-01-01

In this study, the effects of gamma radiation on two hormone refractory human prostate cancer cell lines, DU 145 and PC-3, were followed. It was shown that gamma radiation induced significant inhibition of cell proliferation and viability in dose dependent manner. Antiproliferative effects of radiation were similar in both cell lines, and more pronounced than cytotoxic effects. In addition to that, PC-3 cell line was more resistant to radiation -induced cytotoxicity. (author)

Investigation of the effect of gamma radiation on lincomycin

International Nuclear Information System (INIS)

Al-Zier, A; Al- Kassiri, H.; Al Aji, Z.

2001-01-01

Sterilization of materials used in medical applications is necessary. Since the use of ethylene oxide will be forbidden in the next future and other sterilization methods as wet, and dry hot sterilization are not suitable for sterilization of drugs, further methods are needed which do not cause a significant decrease in the physical and chemical drug properties. Radiation sterilization can help in many cases. So Gamma or electron radiations were used for sterilization of antibiotics in the solid state as mentioned in the literature. Some antibiotics are already exposed to gamma or electron beam irradiation, and showed significant radiation resistance for low doses, but even small amounts of degradation products are not desirable

Feasibility Study on Fiber-optic Radiation Sensor for Remote Gamma-ray Spectroscopy

International Nuclear Information System (INIS)

Jeon, Hyesu; Jang, Kyoung Won; Shin, Sang Hun and others

2014-01-01

In this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors. As a result, the BGO was suitable for the sensing probe of fiber-optic radiation sensor due to its high scintillation output and exact photoelectric peak for the gamma-ray energy. The basic principle of radiation detection is to detect the signals caused by interactions between radiations and materials. There are various types of radiation detectors depending on types of radiation to be detected and physical quantities to be measured. As one of the radiation detectors, a fiber-optic radiation sensor using a scintillator and an optical fiber has two advantages such as no space restraint and remote sensing. Moreover, in nuclear environments, this kind of sensor has immunities for electromagnetic field, temperature, and pressure. Thus, the fiber-optic radiation sensor can be used in various fields including nondestructive inspection, radioactive waste management, nuclear safety, radiodiagnosis and radiation therapy. As a fundamental study of the fiber-optic radiation sensor for remote gamma-ray spectroscopy, in this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors

Scattered radiation in fan beam imaging systems

International Nuclear Information System (INIS)

Johns, P.C.; Yaffe, M.

1982-01-01

Scatter-to-primary energy fluence ratios (S/P) have been studied for fan x-ray beams as used in CT scanners and slit projection radiography systems. The dependence of S/P on phantom diameter, distance from phantom to image receptor, and kilovoltage is presented. An empirical equation is given that predicts S/P over a wide range of fan beam imaging configurations. For CT body scans on a 4th-generation machine, S/P is approximately 5%. Scattered radiation can produce a significant cupping artefact in CT images which is similar to that due to beam hardening. When multiple slices are used in scanned slit radiography, they can be arranged such that the increase in S/P is negligible. Calculations of scatter-to-primary ratios for first order scattering showed that for fan beams the contribution of coherent scatter is comparable to or greater than that of incoherent first scatter

Several problems of the theory of transition radiation and transition scattering

International Nuclear Information System (INIS)

Ginzburg, V.L.; Tsytovich, V.N.

1979-01-01

The process of transition radiation is a very general one. It appears if some source, which does not have a proper frequency (for example a point charge, multipole etc), is moving with a constant velocity in an inhomogeneous and/or nonstationary medium. In the case of a periodic medium the transition radiation has some special peculiarities and is called the resonance transition radiation or transition scattering. Transition scattering occurs particularly in the case when some wave of dielectric permittivity acts on a nonmoving (fixed) charge. The processes of transition radiation and transition scattering have analogies outside electrodynamics similarly to the Vavilov-Cherenkov emission. The latter occurs also for a source moving with a constant velocity but in a homogeneous medium (and only if the velocity of the source exceeds the wave phase velocity in the medium). The present review is dealing with several problems of the theory of transition radiation and transition scattering. Attention is paid mainly to the formulation of the problems and to revealing characterisic features and peculiarities of the phenomena described. (Auth.)

Qualitative evaluation of the DNA degradation in plague insects exposed to gamma radiation

International Nuclear Information System (INIS)

Ortega, Yuriko; Agapito, Juan; Vargas, Johnny; Vivanco, Monica; Martinez, Norberta

2014-01-01

Insects produce large losses in stored grain depending on the type of cereal and storage time and other factors. The rice weevil Sitophilus oryzae L and the false flour beetle Tribolium confusum are important pests of stored grain. The study aimed to qualitatively evaluate the effect of gamma radiation on the DNA of two species of insect pests from samples stored Chullpi and white corn infested with adult weevils. Samples were treated with radiation doses of 100, 400, 1000 and 2000 Gy and DNA extraction was obtained by three methods: TNES-urea, CTAB and NaOH. The DNA damage induced by gamma radiation in weevils was determined by gel electrophoresis. As a result, it was found that exposure of adult weevils to a radiation dose of 100 Gy and 400 caused an average mortality of the insects, showing a degree of resistance to gamma radiation. However, radiation doses of 1000 and 2000 Gy caused 100 % mortality of insects. Preliminary results show that DNA damage is proportional to the amount of gamma radiation. (authors).

Repair effects of exogenous SOD on Bacillus subtilis against gamma radiation exposure

International Nuclear Information System (INIS)

Chen, Xiaoming; Zhang, E.; Fang, Liu; Zhang, Jianguo; Zhu, Jie; He, Wei; Luo, Xuegang

2013-01-01

Superoxide dismutase (SOD) is an enzyme that removes free radicals from cells in many organisms. In order to further characterize these repair effects and their mechanism when subjected to radiation, Bacillus subtilis cells were exposed to gamma radiation and the cell survival rate, intracellular SOD activity, and DNA double-strand breakage were investigated. Vegetative cells of B. subtilis were irradiated by 60 Co gamma radiation at varying doses and subsequently exposed to varying levels of exogenous SOD. Standard plate-count, xanthine oxidase, and pulsed-field gel electrophoresis (PFGE) methods were employed to investigate the repair effects. The results showed that the exogenous SOD could significantly improve cell survival rate and intracellular SOD activity after gamma radiation. The cell survival rate was elevated 30–87 times above levels observed in control samples. Adding exogenous SOD into gamma irradiated cells may dramatically increase intracellular SOD activity (p 60 Co γ radiation and exposed to exogenous SOD. • Adding exogenous SOD into γ-irradiated cells may dramatically increase cell survival rate. • DNA strand scission may be prevented by addition of SOD. • Exogenous SOD may have the ability to repair cell damage after γ-rays radiation

Gamma radiation and gamma ray protection factors of ships in various situations of radioactive fall-out

International Nuclear Information System (INIS)

Brehm, E.H.; Holst, T.

1975-01-01

In this report the development of methods of evaluating gamma ray protection factors (GSF) of ships for various situations of radioactive fall-out is described. The joining calculations of gamma ray protection factors are performed by the newly developed computer procedure GASUFA. These protection factors determine - in connection with a measured gamma radiation dose at a given detector point - the gamma radiation in different compartments of the ships. The computer program GASUFA is able to perform calculations considering the dependence of energy, place and time for the following situations: - the ship is under a radioactive cloud without fall-out; - the ship is under a radioactive cloud with fall-out; - the ship is contaminated by radioactive fall-out; - the clean or decontaminated ship is going through a zone, which is contaminated by radioactive fall-out; - the ship and the surrounding water surface are contaminated by radioactive fall-out. (orig.) [de

Risk to Krakow population of gamma radiation from building materials

International Nuclear Information System (INIS)

Koperski, J.; Jasinska, M.

1980-01-01

A statistics was made of 7128 dwelling-houses considering their age, types of building materials and density of population. Gamma dose rates were measured by means of the TL and pressurized ionization chamber techniques inside 300 buildings and in 44 points outdoors over different kinds of beddings. Personal doses of 49 inhabitants of the buildings monitored were also recorded. By means of the spectrometric analysis of gamma radiation, and basing on a specially developed computational programme ''DOZA'' mean concentrations of 40 K, 226 Ra and 232 Th in 61 samples of building materials were evaluated. It was found that the mean personal dose rate as well as the mean indoor dose rate equals 5.7 urad/h /15.8 pGy/s/ and is about 19% higher than the dose outdoors which equals 4.8 urad/h /13.3 pGy/s/. Gamma dose rates inside the buildings made of gravel-sand concrete elements are about 10% lower than those in the buildings made of red bricks. Mean annual dose equivalent per capita from gamma radiation of building materials equals 40.6 mrem/y /406 uSv/y/, which constitutes about 57% of total annual dose equivalent per capita from all environmental sources of gamma radiation in the residential districts in Krakow. (author)

Use of implicit Monte Carlo radiation transport with hydrodynamics and compton scattering

International Nuclear Information System (INIS)

Fleck, J.A. Jr.

1971-03-01

It is shown that the combination of implicit radiation transport and hydrodynamics, Compton scattering, and any other energy transport can be simply carried out by a ''splitting'' procedure. Contributions to material energy exchange can be reckoned separately for hydrodynamics, radiation transport without scattering, Compton scattering, plus any other possible energy exchange mechanism. The radiation transport phase of the calculation would be implicit, but the hydrodynamics and Compton portions would not, leading to possible time step controls. The time step restrictions which occur on radiation transfer due to large Planck mean absorption cross-sections would not occur

Degradation of electrical insulation of polyethylene under thermal and radiation environment, (4). [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Shuhei; Murabayashi, Fumio; Sawa, Goro [Mie Univ., Tsu (Japan); Yamaguchi, Shinji; Ieda, Masayuki

1982-12-01

Although the quality assurance guideline for the cables used for the safety and protection systems of nuclear power plants is given by IEEE Standards 323 and 383-1974, in addition, it is important to clarify the aging process under the complex environment of heat and radiation and the equivalence of the accelerated aging test of insulating materials. The authors performed the sequential (H.T-..gamma.. or ..gamma..-HT) and simultaneous (..gamma.., HT) application of respective aging factors of heat and radiation to non-additive low density polyethylene films by changing dose rate as the first stage, to clarify the dose rate dependence of the aging. They mainly investigated the dielectric properties, and forwarded investigation based on the change of carbonyl group by infrared spectrometry and residual free radicals by ESR analysis. In the samples irradiated with ..gamma..-ray only and those irradiated with ..gamma..-ray after thermal treatment for 7 hours at 90 deg C, the absorption coefficient ..cap alpha.. of carbonyl group increased with dose in the range from 3 Mrad to 60 Mrad, and both samples showed approximately the same ..cap alpha.. value. The ..cap alpha.. value of the samples thermally treated after irradiation was larger than that of the samples treated in the reverse order, and the difference between them increased with the increase of dose. The values of dielectric tangent delta at room temperature and 1 kHz for the samples (..gamma..) and (HT-..gamma..) increased with dose, and were almost the same, but those for the samples (..gamma..-HT) and (..gamma.., HT) were larger than the former two.

Portable neutron and gamma-radiation instruments

International Nuclear Information System (INIS)

Murray, W.S.; Butterfield, K.B.

1990-01-01

This paper reports on the design and building of a smart neutron and gamma-radiation detection systems with embedded microprocessors programmed in the FORTH language. These portable instruments can be battery-powered and can provide many analysis functions not available in most radiation detectors. Local operation of the instruments is menu-driven through a graphics liquid crystal display and hex keypad; remote operation is through a serial communications link. While some instruments simply count particles, others determine the energy of the radiation as well as the intensity. The functions the authors have provided include absolute source-strength determination. Feynmann variance analysis, sequential-probability ratio test, and time-history recording

Co-60 gamma radiation assisted diffusion of iodine in polypropylene

Energy Technology Data Exchange (ETDEWEB)

Mathakari, N.L.; Bhoraskar, V.N. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune, Maharashtra 411007 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ernet.i [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune, Maharashtra 411007 (India)

2010-09-15

Thin films of polypropylene having dimensions 50 mm x 15 mm x 350 {mu}m were immersed in 1 N iodine solution and then irradiated with Co-60 gamma radiation for the periods of 48, 96 and 144 h at the doses varying from 14.4 to 43.2 kGy. The films were also kept immersed in iodine solution for similar periods but without irradiation. Furthermore, the films were also directly-irradiated with Co-60 gamma radiation for similar periods and doses. The radiation-iodinated, plain-iodinated and directly-irradiated samples were characterized by using various techniques such as weight gain EDS, SEM, FTIR, UV-visible spectroscopy, contact angle and XRD. Weight gain, EDS and SEM collectively reveal that gamma irradiation enhances iodine intake in polypropylene. FTIR, EDS and contact angle measurements indicate that presence of iodine during irradiation resists radiation induced carbonylation of polypropylene. FTIR also shows presence of HOI (Hypoiodous acid) species instead of expected C-I bonds. UV-visible analysis unambiguously shows that presence of iodine enhances radiation induced band gap reduction process of polypropylene. XRD indicates that iodine decreases the crystallinity of polypropylene.

Application of the equivalent radiator method for radiative corrections to the spectra of elastic electron scattering by nuclei

Directory of Open Access Journals (Sweden)

I. S. Timchenko

2015-07-01

Full Text Available For calculating the radiative tails in the spectra of inelastic electron scattering by nuclei, the approximation, namely, the equivalent radiator method (ERM, is used. However, the applicability of this method for evaluating the radiative tail from the elastic scattering peak has been little investigated, and therefore, it has become the subject of the present study for the case of light nuclei. As a result, spectral regions were found, where a significant discrepancy between the ERM calculation and the exact-formula calculation was observed. A link was established between this phenomenon and the diffraction minimum of the squared form-factor of the nuclear ground state. Varieties of calculations were carried out for different kinematics of electron scattering by nuclei. The analysis of the calculation results has shown the conditions, at which the equivalent radiator method can be applied for adequately evaluating the radiative tail of the elastic scattering peak.

Level of terrestrial gamma radiation and doses to population in Jiangsu province

International Nuclear Information System (INIS)

1985-01-01

In this paper the results of investigation of terrestrial gamma radiation level in Jiangsu Province are reported and the population doses due to this radiation are estimated. The sketch map of the geographical distribution of the terrestrial gamma radiation level is given. In this investigation FD-71 portable scintillation counters and RSS-111 high pressure ionization chambers were used. The results showed that the terrestrial gamma absorbed dose rates in air for indoors and outdoors were 10.7 x 10 -8 Gy/h and 6.5 x 10 -8 Gy/h (weighted values) respectively. The indoors-to-outdoors ratio was 1.65. The total (indoor plus outdoor) annual effective dose equivalent from terrestrial gamma radiation, averaged over the population in this province, was 6.0 x 10 -4 Sv. The collective annual effective dose equivalent was 3.6 x 10 4 man.Sv. Therefore, the absorbed dose to population in Jiangsu Province is in the range of the normal background

Disinfection of sewage water and sludge using gamma radiation

International Nuclear Information System (INIS)

Musaad, R.M.A.

2008-04-01

This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6 0 cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D 10 ) and 50% (D 50 ) were determined for each species. The D 10 values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D 50 fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

Inhaled /sup 147/Pm and/or total-body gamma radiation: Early mortality and morbidity in rats

Energy Technology Data Exchange (ETDEWEB)

Filipy, R.E.; Lauhala, K.E.; McGee, D.R.; Cannon, W.C.; Buschbom, R.L.; Decker, J.R.; Kuffel, E.G.; Park, J.F.; Ragan, H.A.; Yaniv, S.S.; Scott, B.R.

1989-05-01

Rats were given doses of /sup 60/Co gamma radiation and/or lung burdens of /sup 147/Pm (in fused aluminosilicate particles) within lethal ranges in an experiment to determine and compare morbidity and mortality responses for the radiation insults within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Acute mortality and morbidity from inhaled promethium were caused primarily by radiation pneumonitis and pulmonary fibrosis that occurred more than 53 days after exposure. Acute mortality and morbidity from total-body gamma irradiation occurred within 30 days of exposure and resulted from the bone-marrow radiation syndrome. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell levels and by reduced body weight gain in animals that survived the acute gamma radiation syndrome. Inhaled promethium caused a loss of body weight and diminished pulmonary function, but its only effect on blood cell levels was lymphocytopenia. Combined gamma irradiation and promethium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Promethium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the later effect of promethium lung burdens. 70 refs., 68 figs., 21 tabs.

Characteristics of liver tissue for attenuate the gamma radiation

International Nuclear Information System (INIS)

Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R.

2005-01-01

It was determined the lineal attenuation coefficient of hepatic tissue before gamma radiation of a source of 137 Cs. When exposing organic material before X or gamma radiation fields, part of the energy of the photons is absorbed by the material, while another part crosses it without producing any effect. The quantity of energy that is absorbed is a measure of the dose that receives the material. The three main mechanisms by means of which the gamma rays interacting with the matter are: The Photoelectric Effect, the Compton dispersion and the Even production; the sum of these three processes is translated in the attenuation coefficient of the radiation. In this work we have used hepatic tissue of bovine, as substitute of the human hepatic tissue, and we have measured the lineal attenuation coefficient for photons of 0.662 MeV. Through a series of calculations we have determined the lineal attenuation coefficient for photons from 10 -3 to 10 -5 MeV and the measured coefficient was compared with the one calculated. (Author)

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

Science.gov (United States)

Vurm, Indrek; Metzger, Brian D.

2018-01-01

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

In vitro cell culture lethal dose submitted to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: carolina_sm@hotmail.com; Ikeda, Tamiko I.; Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

2009-07-01

The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that {sup 60}Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

In vitro cell culture lethal dose submitted to gamma radiation

International Nuclear Information System (INIS)

Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto; Ikeda, Tamiko I.; Cruz, Aurea S.

2009-01-01

The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that 60 Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

Control device intended for a gamma radiation measuring instrument

International Nuclear Information System (INIS)

1976-01-01

This invention concerns a monitoring device for a gamma radiation measuring instrument or radiation meter, in which the radiation to be measured brings about, inter alia, the ionisation of a gas and the generation of current pulses. The dial of this meter is generally calibrated in roentgens per hour, i.e. in radiation rate units. This instrument of very simple design is remarkable for its operating reliability. Preferably placed at the inlet to a radioactive area, it enables every user of a ratemeter to check, over the entire measuring range of this instrument, its proper operation prior to entering the area. To this effect, the monitoring device in question has a thick wall lead castle, having an internal cavity in which is mounted a radioactive source delivering a gamma radiation with given constant characteristics, through a measurement window closed by a calibrated plug. Lead doors articulated on the castle can be superimposed on this window to bring about a given attenuation of the radiation coming from the source and delivered to the exterior of the castle [fr

Radiation anomaly detection algorithms for field-acquired gamma energy spectra

Science.gov (United States)

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

2015-08-01

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

Measurement of gamma radiation doses at the RA reactor by thermoluminescent dosemeters

International Nuclear Information System (INIS)

Prokic, M.

1974-01-01

This paper presents the procedures and gamma radiation doses measured at the exit from the horizontal experimental channel HK-5, vertical experimental channel VK-5 and in the thermal column of the RA reactor in Vinca. Measurement of gamma radiation dose in the mixed intense gamma and neutron radiation field was done by two types of thermoluminescent dosemeters, LiF (TLD-700) and CaF 2 (TLD-08). Gamma dose in the VK-5 was measured in the air and on the bottle filled with tissue-equivalent solution. Increase of the dose on the surface of the bottle was 2.3 compared to the gamma dose value in the air. Correction for the influence of neutrons having different energies was done by using the known sensitivity values of both TL dosemeter types for thermal, intermediate and fast neutrons. Results showed that the TLD-700 dosemeter contains 5 time more Li-6 isotopes (0.035%) than the declared value causing increased neutron sensitivity of this dosemeter. This paper includes numerical sensitivity data for neutrons of different energies for both types of TL dosemeters. Neutron sensitivity values for TLD-700 are related to LiF with 0.035% of Li-6 isotope. Result of measurement have also shown that the CaF 2 :Mn (TLD-08) thermoluminescent dosemeter is more suitable for gamma radiation dose measurements in mixed n-gamma fields with intensive neutron fluxes due to lower neutron sensitivity compared to TLD-700 [sr

Nonlinear Scattering of VLF Waves in the Radiation Belts

Science.gov (United States)

Crabtree, Chris; Rudakov, Leonid; Ganguli, Guru; Mithaiwala, Manish

2014-10-01

Electromagnetic VLF waves, such as whistler mode waves, control the lifetime of trapped electrons in the radiation belts by pitch-angle scattering. Since the pitch-angle scattering rate is a strong function of the wave properties, a solid understanding of VLF wave sources and propagation in the magnetosphere is critical to accurately calculate electron lifetimes. Nonlinear scattering (Nonlinear Landau Damping) is a mechanism that can strongly alter VLF wave propagation [Ganguli et al. 2010], primarily by altering the direction of propagation, and has not been accounted for in previous models of radiation belt dynamics. Laboratory results have confirmed the dramatic change in propagation direction when the pump wave has sufficient amplitude to exceed the nonlinear threshold [Tejero et al. 2014]. Recent results show that the threshold for nonlinear scattering can often be met by naturally occurring VLF waves in the magnetosphere, with wave magnetic fields of the order of 50-100 pT inside the plasmapause. Nonlinear scattering can then dramatically alter the macroscopic dynamics of waves in the radiation belts leading to the formation of a long-lasting wave-cavity [Crabtree et al. 2012] and, when amplification is present, a multi-pass amplifier [Ganguli et al. 2012]. By considering these effects, the lifetimes of electrons can be dramatically reduced. This work is supported by the Naval Research Laboratory base program.

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

International Nuclear Information System (INIS)

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

2001-01-01

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

Characterizing the behavior of scattered radiation in multi-energy x-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Sossin, Artur, E-mail: artur.sossin@gmail.com [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Rebuffel, V.; Tabary, J. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Létang, J.M.; Freud, N. [Univ Lyon, INSA-Lyon, Université Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Centre Léon Bérard, CREATIS UMR 5220 U1206, F-69373 Lyon (France); Verger, L. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France)

2017-04-01

Scattered radiation results in various undesirable effects in medical diagnostics, non-destructive testing (NDT) and security x-ray imaging. Despite numerous studies characterizing this phenomenon and its effects, the knowledge of its behavior in the energy domain remains limited. The present study aims at summarizing some key insights on scattered radiation originating from the inspected object. In addition, various simulations and experiments with limited collimation on both simplified and realistic phantoms were conducted in order to study scatter behavior in multi-energy x-ray imaging. Results showed that the spectrum shape of the scatter component can be considered preserved in the first approximation across the image plane for various acquisition geometries and phantoms. The variations exhibited by the scatter spectrum were below 10% for most examined cases. Furthermore, the corresponding spectrum shape proved to be also relatively invariant for different experimental angular projections of one of the examined phantoms. The observed property of scattered radiation can potentially lead to the decoupling of spatial and energy scatter components, which can in turn enable speed ups in scatter simulations and reduce the complexity of scatter correction.

Inelastic scattering in condensed matter with high intensity Mossbauer radiation: Progress report, March 1, 1985-October 31, 1987

International Nuclear Information System (INIS)

Yelon, W.B.; Schupp, G.

1987-10-01

A facility for high intensity Moessbauer scattering has been commissioned at the University of Missouri Research Reactor (MURR) as well as a facility at Purdue University using special isotopes produced at MURR. A number of scattering studies have been successfully carried out, including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na and the satellite reflection Debye-Waller factor in TaS 2 which indicates phason rather than phonon behavior. High precision, fundamental Moessbauer effect studies have also been carried out using scattering to filter unwanted radiation. These have led to a new Fourier transform method for describing Moessbauer effect (ME) lineshape. This method allows complete correction for source resonance self-absorption (SRSA) and the accurate representation of interference effects that add an asymmetric component to the ME lines. This analysis is important to both the funadmental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct elastic fractions and lineshape parameters. These advances, coupled to our improvements in MIcrofoil Conversion Electron (MICE) spectroscopy, lay the foundation for the proposed research outlined in this request for a three-year renewal of DOE support

Gamma-radiation effect on diamond and steel during their irradiation in WWER type reactors

International Nuclear Information System (INIS)

Nikolaenko, V.A.; Karpukhin, V.I.; Amaev, A.D.; Vikhrov, V.I.; Korolev, Yu.N.; Krasikov, E.A.

1996-01-01

A study is made into the influence of reactor gamma radiation on expansion of crystal lattice in diamond. The data obtained are compared to those on radiation embrittlement of reactor vessel steels. The necessity of taking into consideration gamma radiation effects on WWER reactor vessel radiation resistance during long-term operation is shown [ru

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

Gamma radiation shielding and optical properties measurements of zinc bismuth borate glasses

International Nuclear Information System (INIS)

Yasaka, P.; Pattanaboonmee, N.; Kim, H.J.; Limkitjaroenporn, P.; Kaewkhao, J.

2014-01-01

Highlights: • 10ZnO:xBi 2 O 3 :(90−x)B 2 O 3 , (ZBB) glasses were prepared. • Radiation shielding and optical properties were investigated. • Higher 25 mol% of Bi 2 O 3 show better shielding property compared with concretes. • ZBB glasses can develop as a Pb-free radiation shielding material. - Abstract: In this work, the zinc bismuth borate (ZBB) glasses of the composition 10ZnO:xBi 2 O 3 :(90−x)B 2 O 3 (where x = 15, 20, 25 and 30 mol%) were prepared by the melt quenching technique. Their radiation shielding and optical properties were investigated and compared with theoretical calculations. The mass attenuation coefficients of ZBB glasses have been measured at different energies obtained from a Compton scattering technique. The results show a decrease of the mass attenuation coefficient, effective atomic number and effective electron density values with increasing of gamma-ray energies; and good agreements between experimental and theoretical values. The glass samples with Bi 2 O 3 concentrations higher than 25 mol% (25 and 30 mol%) were observed with lower mean free path (MFP) values than all the standard shielding concretes studied. These results are indications that the ZBB glasses in the present study may be developed as a lead-free radiation shielding material in the investigated energy range

Method and apparatus for measuring incombustible content of coal mine dust using gamma-ray backscatter

International Nuclear Information System (INIS)

Armstrong, F.E.

1976-01-01

A method and apparatus for measuring incombustible content of particulate material, particularly coal mine dust, include placing a sample of the particulate material in a container to define a pair of angularly oriented surfaces of the sample, directing an incident gamma-ray beam from a radiation source at one surface of the sample and detecting gamma-ray backscatter from the other surface of the sample with a radiation detector having an output operating a display to indicate incombustible content of the sample. The positioning of the source and detector along different surfaces of the sample permits the depth of the scattering volume defined by intersection of the incident beam and a detection cone from the detector to be selected such that variations in scattered radiation produced by variations in density of the sample are compensated by variations in the attenuation of the incident beam and the gamma-ray backscatter. 17 claims 5 figures

Investigation of Electricity Generation by Using Gamma Radiation from Spent Fuels

International Nuclear Information System (INIS)

Lee, Haneol; Yim, Man-Sung Yim

2015-01-01

The purpose of this study is to investigate the electric power generation with scale spent fuel. OrigenArp has analyzed gamma radiation environment of spent fuel assembly, MCNPX has analyzed the scintillator behavior, and experimental work has analyzed the electric output of photovoltaic cell. Gamma radiation environment analysis result indicates gamma source rapidly decreases for the early storage period. Scintillator analysis result calculates the photon flux distribution which enters photovoltaic cell. Photovoltaic cell experiment calculates electric current, voltage current generation per each system unit. Generated electric power can be used to cope with existing safety system (i.e. storage monitoring system) under severe accident or to operate security system under external invasion situation (i.e. passive physical barrier system). Several researchers have shown that converting radiation energy into electric energy is possible. Karl Scharf studied the direct electric conversion of radiation energy by using photovoltaic cells. Researchers in University of Massachusetts Lowell have studied radiation-electric energy conversion by using gadolinium oxide scintillator and dye sensitized solar cell (DSSCs) and N. Horuichi et al. studied radiation-electric energy conversion by using inorganic scintillators and amorphous and crystal photovoltaic cells

Quality control of gamma radiation measuring systems

International Nuclear Information System (INIS)

Surma, M.J.

2002-01-01

The problem of quality control and assurance of gamma radiation measuring systems has been described in detail. The factors deciding of high quality of radiometric measurements as well as statistical testing and calibration of measuring systems have been presented and discussed

Automated TLD system for gamma radiation monitoring

International Nuclear Information System (INIS)

Nyberg, P.C.; Ott, J.D.; Edmonds, C.M.; Hopper, J.L.

1979-01-01

A gamma radiation monitoring system utilizing a commercially available TLD reader and unique microcomputer control has been built to assess the external radiation exposure to the resident population near a nuclear weapons testing facility. Maximum use of the microcomputer was made to increase the efficiency of data acquisition, transmission, and preparation, and to reduce operational costs. The system was tested for conformance with an applicable national standard for TLD's used in environmental measurements

Coherence effects in radiative scattering

International Nuclear Information System (INIS)

Knoll, J.; Lenk, R.

1993-03-01

The bremsstrahl-production of photons in dense matter is reinvestigated using the example of an exactly solvable quantum mechanical model in one space dimension. Coherence phenomena between successive radiative scatterings among the constituents lead to a modification of the production cross section in the medium relative to the incoherent quasi-free prescription used in kinetic models. Analytic expressions for the correction factor have been derived comparing the quantum rates with the corresponding incoherent quasi-free rates. The result has implications for the kinetic description of all kinds of radiative processes in nucleus-nucleus collisions, both on the level of hadron and parton dynamics. (orig.)

Rheology of Indian Honey: Effect of Temperature and Gamma Radiation

Directory of Open Access Journals (Sweden)

Sudhanshu Saxena

2014-01-01

Full Text Available Honey brands commonly available in Indian market were characterized for their rheological and thermal properties. Viscosity of all the honey samples belonging to different commercial brands was found to decrease with increase in temperature (5–40°C and their sensitivity towards temperature varied significantly as explained by calculating activation energy based on Arrhenius model and ranged from 54.0 to 89.0 kJ/mol. However, shear rate was not found to alter the viscosity of honey indicating their Newtonian character and the shear stress varied linearly with shear rate for all honey samples. Honey is known to contain pathogenic microbial spores and in our earlier study gamma radiation was found to be effective in achieving microbial decontamination of honey. The effect of gamma radiation (5–15 kGy on rheological properties of honey was assessed, and it was found to remain unchanged upon radiation treatment. The glass transition temperatures (Tg of these honey analyzed by differential scanning calorimetry varied from −44.1 to −54.1°C and remained unchanged upon gamma radiation treatment. The results provide information about some key physical properties of commercial Indian honey. Radiation treatment which is useful for ensuring microbial safety of honey does not alter these properties.

Towards a new thickness-independent gamma radiation plastic film dosimeter

International Nuclear Information System (INIS)

Vieira, Marli Barbosa; Araujo, Patricia L.; Araujo, Elma S.

2013-01-01

A 100% national single-use gamma radiation plastic film dosimeter is presented in this work. A new approach for the development of this material allowed a step forward in the performance of poly (methyl metacrylate) films (PMMA) colored with bromothymol blue (BTB) acid-base indicator. We manage to improve dosimeter performance by introducing a gamma radiation insensitive dye to compensate film thickness variations. By doing so, we were able to obtain consistent dose-response correlations within a set of samples presenting 46 to 110 micrometers in thickness. Hence, our PMMA/BTB-P film dosimeter is suitable to measure absorbed dose in the 2-100kGy range even when film thickness undergoes more than 100% of variation. In addition, dose response data remain practically unaltered for four months after the exposure, when dosimeter films are kept in dark conditions and under refrigeration. The radiation effects on the optical properties were evaluated for Ultraviolet-Visible (UV-Vis) spectrophotometric analysis. Data of characteristic dose-response correlation in terms of changes in the maximum UV-Vis absorption due to radiation, and stability in time are also described. This potential new product is a promising tool for industrial radiation facilities, especially in gamma sterilization of medical supplies. (author)

The effect of gamma radiation and caffeine during the embrionic development of Biomphalaria glabrata

International Nuclear Information System (INIS)

Kawano, T.

1982-01-01

Some experiments have been carried out, dealing with the interations of caffeine and gamma radiation in the embryonic development of Biomphalaria glabrata. Gamma radiation was used in a dosis of 1000r (exposure time of 1/2 hour) and caffeine concentration was 0.1% (Exposure time of 24 hours). Experiment I. The embryos were irradiated before treatment with caffeine. In this experiment we have observed a synergistic effect between caffeine and gamma radiation. Experiment II. The embryos in the caffeine solution were irradiated 8 hours after the beginning of the experiment. The synergistic effect observed in this experiment was reduced when compared with the first one. Experiment III. In this experiment we made the pre-treatment with caffeine. We have not observed any synergistic effect between the drug and gamma radiation. Experiment IV. Embryos were irradiated, and after 24 hours treated with caffeine during another 24 hours. As in the previous experiment, we have not observed any synergism between the radiation and the drug. According to the above results, we conclude that the synergistic effect between caffeine and gamma radiation in the embryos was more effective when the embryos have been treated with caffeine after irradiation. (Author) [pt

Disinfection of sewage water and sludge using gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Musaad, R M.A. [Department of Radiation Chemistry, Atomic Energy Research Coordination Council, Sudan Academy of Sciences, Khartoum (Sudan)

2008-04-15

This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6{sup 0} cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D{sub 10}) and 50% (D {sub 50}) were determined for each species. The D{sub 10} values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D{sub 50} fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

Dose rate modelled for the outdoors of a gamma irradiation

International Nuclear Information System (INIS)

Mangussi, J

2012-01-01

A model for the absorbed dose rate calculation on the surroundings of a gamma irradiation plant is developed. In such plants, a part of the radiation emitted upwards reach's the outdoors. The Compton scatterings on the wall of the exhausting pipes through de plant roof and on the outdoors air are modelled. The absorbed dose rate generated by the scattered radiation as far as 200 m is calculated. The results of the models, to be used for the irradiation plant design and for the environmental studies, are showed on graphics (author)

Scatter radiation from chest radiographs: is there a risk to infants in a typical NICU?

International Nuclear Information System (INIS)

Trinh, Angela M.; Schoenfeld, Alan H.; Levin, Terry L.

2010-01-01

To evaluate the dose of scatter radiation to infants in a NICU in order to determine the minimal safe distance between isolettes. Dose secondary to scattered radiation from an acrylic phantom exposed to vertical and horizontal beam exposures at 56 kVp was measured at 93 cm and 125 cm from the center of the phantom. This corresponds to 2 and 3 ft between standard isolettes, respectively. For horizontal exposures, the dosimeter was placed directly behind a CR plate and scatter dose at 90-degrees and 135-degrees from the incident beam was also measured. Exposures were obtained at 160 mAs and the results were extrapolated to correspond to 2.5 mAs. Four measurements were taken at each point and averaged. At 125 cm and 93 cm there was minimal scatter compared to daily natural background radiation dose (8.493 μGy). Greatest scatter dose obtained from a horizontal beam exposure at 135 from the incident beam was still far below background radiation. Scatter radiation dose from a single exposure as well as cumulative scatter dose from numerous exposures is significantly below natural background radiation. Infants in neighboring isolettes are not at added risk from radiation scatter as long as the isolettes are separated by at least 2 ft. (orig.)

Density measurement using gamma radiation - theory and application

International Nuclear Information System (INIS)

Springer, E.K.

1979-01-01

There are still widespread uncertainties about the use and safety of gamma radiation in industries. This paper describes, by the example of radiometric density measurement, the theory of gamma radiation. The differences and advantages of both types of detectors, the ionization chamber and the scintillation counter, are discussed. The degree of accuracy which can be expected from the radiometric density meter will be defined, and the inter-relationship: source strength - measuring range - measuring length(normally the pipe diameter) in relation to the measuring accuracy required will be explained in detail. The use of radioactive material requires the permission of the Atomic Energy Board. The formalities involved to receive a user's licence and the implementations of safety standards set by the local authorities are discussed in depth [af

Gamma radiation in pest control at the storehouses

International Nuclear Information System (INIS)

Tsvetkov, D.; Atanasov, Khr.; Berberov, D.

1974-01-01

The prospects of radiation control of wheat grain pests in Bulgaria are shown, drawing the following main conclusions: The lethal doses of gamma rays for the granary weevil, grain borer and confused flour beetle are fairly high - of the order of 300,000-400,000 r; the sterilizing doses of gamma rays arrest the reproduction of granary and rice weevils as well as of confused flour beetles. The irradiated insects, however, retain their sex activity and so may inhibit the reproduction of fertile populations. Irradiation strongly reduces the life span of, and consequently the damage done by, the insects; radiation control of stored-grain pests by using sterilizing doses does not deteriorate the technological quality of the wheat grain. (E.T.)

Sensitivity of hyperthermia-treated human cells to killing by ultraviolet or gamma radiation

International Nuclear Information System (INIS)

Mitchel, R.E.; Smith, B.P.; Wheatly, N.; Chan, A.; Child, S.; Paterson, M.C.

1985-01-01

Human xeroderma pigmentosum (XP) or Fanconi anemia (FA) fibroblasts displayed shouldered 45 0 C heat survival curves not significantly different from normal fibroblasts, a result similar to that previously found for ataxia telangiectasia (AT) cells, indicating heat resistance is not linked to either uv or low-LET ionizing radiation resistance. Hyperthermia (45 0 C) sensitized normal and XP fibroblasts to killing by gamma radiation but failed to sensitize the cells to the lethal effects of 254 nm uv radiation. Thermal inhibition of repair of ionizing radiation lesions but not uv-induced lesions appears to contribute synergistically to cell death. The thermal enhancement ratio (TER) for the synergistic interaction of hyperthermia (45 0 C, 30 min) and gamma radiation was significantly lower in one FA and two strains (TER = 1.7-1.8) than that reported previously for three normal strains (TER = 2.5-3.0). These XP and FA strains may be more gamma sensitive than normal human fibroblasts. Since hyperthermia treatment only slightly increases the gamma-radiation sensitivity of ataxia telangiectasia (AT) fibroblasts compared to normal strains, it is possible that the degree of thermal enhancement attainable reflects the genetically inherent ionizing radiation repair capacity of the cells. The data indicate that both repair inhibition and particular lesion types are required for lethal synergism between heat and radiation. We therefore postulate that the transient thermal inhibition of repair results in the conversion of gamma-induced lesions to irrepairable lethal damage, while uv-type damage can remain unaltered during this period

Analysis and characterization. Nuclear resonant scattering with the synchrotron radiation

International Nuclear Information System (INIS)

Ruffer, R.; Teillet, J.

2003-01-01

The nuclear resonant scattering using the synchrotron radiation combines the uncommon properties of the Moessbauer spectroscopy and those of the synchrotron radiation. Since its first observation in 1984, this technique and its applications have been developed rapidly. The nuclear resonant scattering is now a standard technique for all the synchrotron radiation sources of the third generation. As the Moessbauer spectroscopy, it is a method of analysis at the atomic scale and a non destructive method. It presents the advantage not to require the use of radioactive sources of incident photons which can be difficult to make, of a lifetime which can be short and of an obviously limited intensity. The current applications are the hyperfine spectroscopy and the structural dynamics. In hyperfine spectroscopy, the nuclear resonant scattering can measure the same size than the Moessbauer spectroscopy. Nevertheless, it is superior in the ranges which exploit the specific properties of the synchrotron radiation, such as the very small samples, the monocrystals, the measures under high pressures, the geometry of small angle incidence for surfaces and multilayers. The structural dynamics, in a time scale of the nanosecond to the microsecond can be measured in the temporal scale. Moreover, the nuclear inelastic scattering gives for the first time a tool which allows to have directly the density of states of phonons and then allow to deduce the dynamical and thermodynamical properties of the lattice. The nuclear resonant scattering technique presented here, which corresponds to the Moessbauer spectroscopy technique (SM), is called 'nuclear forward scattering' (NFS). Current applications in physics and chemistry are develop. The NFS is compared to the usual SM technique in order to reveal its advantages and disadvantages. (O.M.)

Neutron inelastic scattering cross sections of 232Th obtained from (n,n/prime/sub gamma/) measurements

International Nuclear Information System (INIS)

Egan, J.J.; Menachery, J.D.; Kegel, G.H.R.; Pullen, D.J.

1980-01-01

The /sup 232/Th(n,n/prime/sub gamma/) reaction has been studied up to 2.1 MeV bombarding energy for states with excitation energies from 700 to 1700 keV. Seventy-five gamma-ray transitions from forty-three above the first excited state have been observed from a disk scatterer with a 40-cm/sup 3/ Ge(Li) detector surrounded by an anti-Compton annulus of NaI(Tl). The time-of-flight technique was employed to further reduce background. Cross sections for twenty-two states are reported here. The data have been corrected for the finite sample effects of neutron and gamma-ray attenuation, and neutron multiple scattering. The results are compared to those of McMurray et al. and to the predictions of the compound nucleus statistical model. A compound nucleus plus direct interaction calculation is also shown for the 1/sup -/ state at 714 kev. 7 refs

Research of pulse gamma ray radiation effect on microcontroller system

International Nuclear Information System (INIS)

Yang Shanchao; Ma Qiang; Jin Xiaoming; Li Ruibin; Lin Dongsheng; Chen Wei; Liu Yan

2012-01-01

An experimental result of power chip LM7805 and microcontroller EE80C196KC20 based on the EE80C196KC20 testing system was presented. The pulse gamma ray radiation effect was investigated using 'Qiangguang-Ⅰ' accelerator. Latchup threshold of the microcontroller was obtained, and the relationship of supply current and I/O output with the transient dose rate was observed. The result shows that the restrainability of power chip on pulse gamma ray radiation induces microcontroller latchup effect. (authors)

Gamma radiation effects in vertically aligned carbon nanotubes

OpenAIRE

Lubkowski, Grzegorz; Kuhnhenn, Jochen; Suhrke, Michael; Weinand, Udo; Endler, Ingolf; Meißner, Frank; Richter, Sylvia

2011-01-01

This paper describes an experimental study of gamma radiation effects in low-density arrays of vertically aligned carbon nanotubes. These arrays are characterized by excellent anti-reflective and absorbing properties for wavelengths from UV to IR, which makes them an interesting option for stray light control in optical space applications. Gamma irradiation equivalent to an estimated surface lifetime exposition in geostationary orbit does not affect the reflectivity of the structures. First h...

CaSO4: Dy + Teflon dosimetric pellets for X, beta and gamma radiation detection

International Nuclear Information System (INIS)

Campos, L.L.; Lima, M.F.

1987-08-01

CaSO 4 : Dy + TEFLON dosimetric pellets with high sensitivity and low cost for X, beta and gamma radiation monitoring were studied and developed by the Dosimetric Material Production Laboratory of the Radiological Protection Departament and are disposable for sale. The thickness of the pellets are suitable for X, beta and gamma radiation measurements. The dosimetric properties of these pellets were determined and presented in this work. The results show the usefulness of 0,20mm thick pellets for beta radiation monitoring and 0,80mm thick pellets for x and gamma radiation detection. (Author) [pt

Gamma radiation scanning of nuclear waste storage tile holes

International Nuclear Information System (INIS)

Das, A.; Yue, S.; Sur, B.; Johnston, J.; Gaudet, M.; Wright, M.; Burton, N.

2010-01-01

Nuclear waste management facilities at Chalk River Laboratories use below-ground 'tile holes' to store solid waste from various activities such as medical radioisotope production. A silicon PIN (p-type-intrinsic-n-type semiconductor) diode based gamma radiation scanning system has been developed and used to profile the gamma radiation fields along the depth of waste storage tile holes by deploying the sensor into verification tubes adjacent to the tile holes themselves. The radiation field measurements were consistent with expected radiation fields in the tile holes based on administrative knowledge of the radioactive contents and their corresponding decay rates. Such measurements allow non-invasive verification of tile hole contents and provide input to the assessment of radiological risk associated with removal of the waste. Using this detector system, radioactive waste that has decayed to very low levels may be identified based on the radiation profile. This information will support planning for possible transfer of this waste to a licensed waste storage facility designed for low level waste, thus freeing storage space for possible tile hole re-use for more highly radioactive waste. (author)

X-Ray and Gamma-Ray Radiation Detector

DEFF Research Database (Denmark)

2015-01-01

Disclosed is a semiconductor radiation detector for detecting X-ray and / or gamma-ray radiation. The detector comprises a converter element for converting incident X-ray and gamma-ray photons into electron-hole pairs, at least one cathode, a plurality of detector electrodes arranged with a pitch...... (P) along a first axis, a plurality of drift electrodes, a readout circuitry being configured to read out signals from the plurality of detector electrodes and a processing unit connected to the readout circuitry and being configured to detect an event in the converter element. The readout circuitry...... is further configured to read out signals from the plurality of drift electrodes, and the processing unit is further configured to estimate a location of the event along the first axis by processing signals obtained from both the detector electrodes and the drift electrodes, the location of the event along...

Responses of a grassland arthropod community to chronic beta and gamma radiation

International Nuclear Information System (INIS)

Styron, C.E.; Dodson, G.J.; Beauchamp, J.J.; Miller, F.L. Jr.

1976-01-01

A long-term project was initiated in 1968 at Oak Ridge National Laboratory to assess effects of mixed beta and gamma radiation from simulated fallout on a grassland ecosystem. Beta and gamma radiation dose rates in microhabitats of the experimentally contaminated enclosure were measured with LiF thermoluminescent microdosimeters. Extensive statistical analyses of data on numbers of individuals collected for each of 76 arthropod and 2 molluscan taxa have identified no lasting significant changes in similarity or species diversity of experimental versus control communities as the result of the long-term irradiation at low dose rates. Natural fluctuations in community dynamics obscured any possible radiation effects. Thus, the apparent threshold for mixed beta and gamma radiation inducing changes in community structure must be above the exposure rate range of 2.3 to 13 rad/day delivered during the 5 yr of observation. Establishing such a threshold is of importance in assessing the impact of communities subjected to chronic, low level environmental exposure to ionizing radiation

Effect of gamma radiation on growth, productivity and protein content of chlorella pyrenoidosa

International Nuclear Information System (INIS)

Fernandez Gonzalez, J.; Martin Moreno, C.

1983-01-01

The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy at a dose rate of 4.500 Gy/h on growth, productivity and protein content of Chlorella Pyroneidosa has been studied. High doses of gamma radiation have been observed to inhibit cellular division of Chlorella Pyrenoidosa. Culture growth stopped 48 hours after irradiation at 5.000 Gy and 72 hours after irradiation at 500 and 1000 Gy. The lowest dose (10 Gy) produced a little growth stimulation that as not statistically significative. Protein and aminoacid content did not show any change for gamma radiation doses studied. (author)

Effect of gamma radiation on growth, productivity and protein content of Chlorella Pyrenoidosa

International Nuclear Information System (INIS)

Martin Moreno, C.; Fernandez Gonzalez, J.

1983-01-01

The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy at a dose rate of 4.500 Gy/h on growth, productivity and protein content of Chlorella pyroneidosa has been studied. High doses of gamma radiation have been observed to inhibit cellular division of Chlorella pyrenoidosa. Culture growth stopped 48 hours after irradiation at 5.000 Gy and 72 hours after irradiation at 500 and 1000 Gy. The lowest dose (10 Gyl produced a little growth stimulation that not statistically significative. Protein and aminoacid content did not show any change for gamma radiation doses studied. (Author) 32 refs

Gamma radiation utilization for polymers synthesis

International Nuclear Information System (INIS)

Santos, L.G. dos; Silva Filho, E.

1990-01-01

Samples of styrene monomer were irradiated with gamma rays from a sup(60)Co source, with doses in the range of zero to 32600 Gray (Gy). Viscosity analysis performed by using the method of Stokes showed an increase in the viscosity of the material. This result characterizes the occurrence of polymerization induced by the radiation. (author)

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

International Nuclear Information System (INIS)

Yuliati, Helfi; Akhadi, Mukhlis

2000-01-01

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

Snowpack snow water equivalent measurement using the attenuation of cosmic gamma radiation

International Nuclear Information System (INIS)

Osterhuber, R.; Condreva, K.

1998-01-01

Incoming, background cosmic radiation constantly fluxes through the earth's atmosphere. The high energy gamma portion of this radiation penetrates many terrestrial objects, including the winter snowpack. The attenuation of this radiation is exponentially related to the mass of the medium through which it penetrates. For the past three winters, a device measuring cosmic gamma radiation--and its attenuation through snow--has been installed at the Central Sierra Snow Laboratory, near Donner Pass, California. This gamma sensor, measuring energy levels between 5 and 15 MeV, has proved to be an accurate, reliable, non-invasive, non-mechanical instrument with which to measure the total snow water equivalent of a snowpack. This paper analyzes three winters' worth of data and discusses the physics and practical application of the sensor for the collection of snow water equivalent data from a remote location

Coherent scattering of electromagnetic radiation by a polarized particle system

International Nuclear Information System (INIS)

Agre, M.Ya.; Rapoport, L.P.

1996-01-01

The paper deals with the development of the theory of coherent scattering of electromagnetic waves by a polarized atom or molecular system. Peculiarities of the angular distribution and polarization peculiarities of scattered radiation are discussed

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

Inactivation and stability of viral diagnostic reagents treated by gamma radiation

International Nuclear Information System (INIS)

White, L.A.; Freeman, C.Y.; Hall, H.E.; Forrester, B.D.

1990-01-01

The objective of this study was to apply the pertinent findings from gamma inactivation of virus infectivity to the production of high quality diagnostic reagents. A Gammacell 220 was used to subject 38 viruses grown in either susceptible tissue cultures or embryonated chicken eggs to various doses of gamma radiation from a cobalt-60 source. The radiation required to reduce viral infectivity was 0.42 to 3.7 megarads (Mrad). The effect of gamma treatment on the antigenic reactivity of reagents for the complement fixation (CF), hemagglutination (HA) and neuraminadase assays was determined. Influenza antigens inactivated with 1.7 Mrad displayed comparable potency, sensitivity, specificity and stability to those inactivated by standard procedures with beta-propiolactone (BPL). Significant inactivation of influenza N1 and B neuraminidase occurred with >2.4 Mrad radiation at temperatures above 4 0 C. All 38 viruses were inactivated, and CF or HA antigens were prepared successfully. Antigenic potency remained stable with all antigens for 3 years and with 83% after 5 years storage. Influenza HA antigens evaluated after 9 years of storage demonstrated 86% stability. Gamma radiation is safer than chemical inactivation procedures and is a reliable and effective replacement for BPL in preparing diagnostic reagents. (author)

Inactivation and stability of viral diagnostic reagents treated by gamma radiation

Energy Technology Data Exchange (ETDEWEB)

White, L A; Freeman, C Y; Hall, H E; Forrester, B D [Department of Health and Human Services, Atlanta, GA (USA)

1990-10-01

The objective of this study was to apply the pertinent findings from gamma inactivation of virus infectivity to the production of high quality diagnostic reagents. A Gammacell 220 was used to subject 38 viruses grown in either susceptible tissue cultures or embryonated chicken eggs to various doses of gamma radiation from a cobalt-60 source. The radiation required to reduce viral infectivity was 0.42 to 3.7 megarads (Mrad). The effect of gamma treatment on the antigenic reactivity of reagents for the complement fixation (CF), hemagglutination (HA) and neuraminadase assays was determined. Influenza antigens inactivated with 1.7 Mrad displayed comparable potency, sensitivity, specificity and stability to those inactivated by standard procedures with beta-propiolactone (BPL). Significant inactivation of influenza N1 and B neuraminidase occurred with >2.4 Mrad radiation at temperatures above 4{sup 0}C. All 38 viruses were inactivated, and CF or HA antigens were prepared successfully. Antigenic potency remained stable with all antigens for 3 years and with 83% after 5 years storage. Influenza HA antigens evaluated after 9 years of storage demonstrated 86% stability. Gamma radiation is safer than chemical inactivation procedures and is a reliable and effective replacement for BPL in preparing diagnostic reagents. (author).

Inactivation of bacteria in sewage sludge by gamma radiation

International Nuclear Information System (INIS)

Pandya, G.A.; Kapila, Smita; Kelkar, V.B.; Negi, Shobha; Modi, V.V.

1987-01-01

The survival of certain bacterial cultures suspended in sewage sludge and exposed to gamma-radiation was studied. The inactivation patterns of most of the organisms were significantly different when irradiation was performed using sewage samples collected in the summer and monsoon seasons. The summer sample collected from the anaerobic digester afforded significant protection to both Gram negative and Gram positive organisms. This was evident by the increase in dose required to bring about a 6 log cycle reduction in viable count of the bacterial cultures, when suspended in sewage samples instead of phosphate buffer. The observations made using monsoon digester samples were quite different. This sewage sludge greatly enhanced inactivation by gamma-radiation in most cases. The effects of certain chemicals on the inactivation patterns of two organisms - Salmonella typhi and Shigella flexneri - were examined. Arsenate, mercury and lead salts sensitised S. typhi, while barium acetate and sodium sulphide protected this culture against gamma-radiation. In the case of Sh. flexneri, barium acetate and iodacetamide proved to be radioprotectors. The effects of some chemicals on the inactivation pattern of Sh. flexneri cells irradiated in sludge are also discussed. (author)

Analysis of portable gamma flaw detectors concerning radiation hygiene

International Nuclear Information System (INIS)

Makarova, T.V.

1982-01-01

Design and shields of gamma flaw detectors as one of the main factors responsible for personnel dose were studied. The analysis was conducted using the results of radiation hygienic surveys of gamma flaw detection laboratories functioning constantly in Estonia. It is shown that recently the replacement of GUP apparatuses by flaw detectors of RID and ''Gamma-RID'' (types which have design and shielding advantages is observed. However personnel doses have not reduced considerably for the last 10 years. This fact is attributed to design disadvantages of the RID and ''Gamma-RID'' apparatuses the removing of which will give the decreasing of annual personnel dose by 80 %

Very Strong TeV Emission as $\\gamma$-Ray Burst Afterglows

CERN Document Server

Totani, T

1998-01-01

Gamma-ray bursts (GRBs) and following afterglows are considered to be produced by dissipation of kinetic energy of a relativistic fireball and radiation process is widely believed as synchrotron radiation or inverse Compton scattering of electrons. We argue that the transfer of kinetic energy of ejecta into electrons may be inefficient process and hence the total energy released by a GRB event is much larger than that emitted in soft gamma-rays, by a factor of \\sim (m_p/m_e). We show that, in this case, very strong emission of TeV gamma-rays is possible due to synchrotron radiation of protons accelerated up to \\sim 10^{21} eV, which are trapped in the magnetic field of afterglow shock and radiate their energy on an observational time scale of \\sim day. This suggests a possibility that GRBs are most energetic in TeV range and such TeV gamma-rays may be detectable from GRBs even at cosmological distances, i.e., z gives a quantitative explanation for the famous long-duration GeV photons detected from GRB940217. ...

Forward-scattered radiation from the compression paddle should be considered in glandular dose estimations

International Nuclear Information System (INIS)

Hemdal, B.

2011-01-01

From major protocols on dosimetry in mammography, there is no doubt that the incident air kerma should be evaluated without backscattered radiation to the dosemeter. However, forward-scattered radiation from the compression paddle is neglected. The aim of this work was to analyse the contribution of forward-scattered radiation for typical air kerma measurements. Measurements of forward-scatter were performed with a plane-parallel ionisation chamber on four mammography units. The forward-scatter contribution to the air kerma was 2-10 % and increased with the compression paddle thickness, but also with the half-value layer value. For incident air kerma in mammography, it can be as important to consider forward scattered as backscattered radiation. If an ionisation chamber is used, the compression paddle should be in contact with the chamber; otherwise the air kerma and absorbed dose will be underestimated. If a dosemeter based on semiconductors with much less sensitivity to scattered radiation is used, it is suggested that a forward-scatter factor (FSF) is applied. Based on the results of this work, FSF=1.06 will lead to a maximum error of ∼4 %. (authors)

Effect of neutron and gamma radiations on zeolite and zeotype materials

International Nuclear Information System (INIS)

Durrani, S.K.

1994-01-01

The influence of gamma and (n, gamma)-radiation on the cation exchange and the structure of zeolite and zeotype materials has been studied. Samples were subjected to different doses of gamma-irradiation varying between 0.5 and 10 MGy and Neutron irradiation flux varied from 1.14 x 10/sup 17/ to 3.88 x /sup 10/sup 17/n cm/sup -2/. Structural effects consequent to gamma irradiation were examined by x-ray diffraction, electron scanning micrographs and FTIR measurements. Neutron and gamma-irradiation and not lead by any appreciable change in the structure, however, the displacement cations to locked-in sites results partial reduced barium and caesium uptake. The decrease of the intensities of the absorption bands of the hydroxy-groups reveals that gamma-irradiation has a strong dehydrating influence. THe effects of gamma-radiation on (UO/sub 2/)/sup 2+/ and Am/sup 3+/ uptake into NH/sub 4/-L and NH/sub 4/-SAPO-34 was also observed. K alpha of the uranyl ions increased with increasing pH up to 6.3. At pH > 3.5, the uranyl ions were precipitated and consequently K alpha values were continued to increased. (author)

Enhancement of ZnO-rGO nanocomposite thin films by gamma radiation for E. coli sensor

Energy Technology Data Exchange (ETDEWEB)

Noor Azmy, Noor Azwen [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Bakar, Ahmad Ashrif A., E-mail: ashrif@ukm.edu.my [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Arsad, Norhana [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Idris, Sarada [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Radiation Facilities Division, Block 42, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Mohmad, Abdul Rahman [MEMS-NEMS and Nanoelectronics, Institute of Microengineering and Nanoelectronics (IMEN), 43650 UKM, Bangi, Selangor (Malaysia); Abdul Hamid, Aidil [School of Biosciences and Biotechnology, Faculty of Science and Technology, 43650 UKM, Bangi, Selangor (Malaysia)

2017-01-15

Highlights: • ZnO-rGO nanocomposite thin films by gamma radiation for E. coli sensor were fabricated for the first time. • Exposed to gamma radiation leads to the change the microstructure of the films. • The optical behaviors of thin films were found to be gamma dose dependent. • The sensors had a linear response with GO concentration. • The sensors exhibited enhanced sensitivity at higher gamma radiation. - Abstract: The fabricated E. coli sensor of ZnO-rGO nanocomposite thin films by gamma radiation was investigated. Nanocomposite films were prepared via sol–gel method and were irradiated at 10 kGy at room temperature. The surface characteristic of as-prepared samples have been characterized by x-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The proposed structure shows that exposed gamma radiation may change the microstructure of the films occurs as a result of their flexible structure. Uv–vis spectra of nanocomposite were studied to investigate the optical behavior of ZnO-rGO films and the optical energy band gap and Urbach energy were found to be gamma dose dependent. The sensing properties were identified by measuring the changes of conductivity of film using I-V measurement. Upon exposure to E. coli, the radiated ZnO-rGO films (1.00 vol% GO) exhibited higher sensitivity, as much as 4.62 × 10{sup −3}, than un-radiated films, 1.04 × 10{sup −3}. This enhancement of the I-V response was attributed to a positive influence of the gamma radiation in these films. The results prove that our ZnO-rGO nanocomposites thin films by gamma radiation demonstrate a strong performance for the detection of microbiological organisms in water.

Gamma radiation in space and in the atmosphere; Rayonnement gamma dans l'espace et dans l'atmosphere

Energy Technology Data Exchange (ETDEWEB)

Rocchia, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-07-01

We have shown that the {gamma} radiation existing in the atmosphere is caused mainly by the Bremsstrahlung of the electrons of the electromagnetic cascades ({approx} 50 per cent of the measured radiation), by the 511 keV radiation produced by the annihilation of positrons created in cascades (8 per cent of the measured intensity) and by the Compton {gamma} degradation of this line (30 per cent of the measured intensity). The rest, slightly over 10 per cent, must be attributed to secondary causes such as the nuclear de-excitation {gamma} to the internal Bremsstrahlung of charged particles created in nuclear stars, and to charged particles crossing our detector, since the latter was not fitted with a device for rejecting these particles. Experiments carried out in rockets at Colomb-Bechar confirm these results and have made it possible to detect and measure a primary {gamma} radiation having an intensity of {approx} 2 {gamma} cm{sup 2} s{sup -1} above 100 keV. The primary spectrum obeys an approximate E{sup -2} law. (author) [French] Nous avons montre que le rayonnement {gamma} existant dans l'atmosphere est provoque principalement por le bremsstrohlung des electrons des cascades electromagnetiques ({approx} 50 pour cent du rayonnement mesure), au rayonnement 511 keV provoque par l'annihilation des positrons crees dans les cascades (8 pour cent de l'intensite mesuree) et aux {gamma} de degradation Compton de cette raie (30 pour cent de l'intensite mesuree). Le reste, soit un peu plus de 10 pour cent, doit etre attribue a des causes secondaires telles que les {gamma} de desexcitation nucleaire, le bremsstrahlung interne des particules chargees creees dans les etoiles nucleaires, et aux particules chargees traversant notre detecteur car celui-ci ne comportait pas de dispositif de rejet de ces particules. Les experiences faites en fusees a Colomb-Bechar ont confirme ces resultats et permis de detecter et mesurer un rayonnement {gamma} primaire dont l

Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation

Energy Technology Data Exchange (ETDEWEB)

Gomes, Tânia, E-mail: tania.gomes@niva.no [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349, Oslo (Norway); Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Xie, Li [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349, Oslo (Norway); Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Brede, Dag; Lind, Ole-Christian [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department for Environmental Sciences, Faculty of Environmental Science & Technology, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432, Ås (Norway); Solhaug, Knut Asbjørn [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Postbox 5003, N-1432, Ås (Norway); Salbu, Brit [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department for Environmental Sciences, Faculty of Environmental Science & Technology, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432, Ås (Norway); and others

2017-02-15

Highlights: • Chlorophyll fluorescence parameters affected at higher dose rates. • Changes in PSII associated with electron transport and energy dissipation pathways. • Dose-dependent ROS production in algae exposed to gamma radiation. • Decrease in photosynthetic efficiency connected to ROS formation. - Abstract: The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49–1677 mGy/h) for 6 h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H{sub 2}DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6 h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first

Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation

International Nuclear Information System (INIS)

Gomes, Tânia; Xie, Li; Brede, Dag; Lind, Ole-Christian; Solhaug, Knut Asbjørn; Salbu, Brit

2017-01-01

Highlights: • Chlorophyll fluorescence parameters affected at higher dose rates. • Changes in PSII associated with electron transport and energy dissipation pathways. • Dose-dependent ROS production in algae exposed to gamma radiation. • Decrease in photosynthetic efficiency connected to ROS formation. - Abstract: The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49–1677 mGy/h) for 6 h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H 2 DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6 h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first report

Calculation of point isotropic buildup factors of gamma rays for water and lead

Directory of Open Access Journals (Sweden)

A. S. H.

2001-12-01

Full Text Available   Exposure buildup factors for water and lead have been calculated by the Monte-Carlo method for an isotropic point source in an infinite homogeneous medium, using the latest cross secions available on the Internet. The types of interactions considered are ,photoelectric effect, incoherent (or bound-electron Compton. Scattering, coherent (or Rayleigh scattering and pair production. Fluorescence radiations have also been taken into acount for lead. For each material, calculations were made at 10 gamma ray energies in the 40 keV to 10 MeV range and up to penetration depths of 10 mean free paths at each energy point. The results presented in this paper can be considered as modified gamma ray exposure buildup factors and be used in radiation shielding designs.

Effects of chemical sensitizers on gamma radiation processing of ...

African Journals Online (AJOL)

The potential of gamma radiation processing in cross-linking natural rubber latex (NRL) for production of dipped goods has been studied. NRL produced in Ghana was irradiated to 10, 20, 30, 40 and 50 kGy, respectively, in a Gamma Chamber of dose rate 0.65 kGy/h. Irradiation of the NRL was also carried out in the ...

On the honeybee resistance to gamma radiation; Sur la resistance au rayonnement gamma de l'abeille ouvriere

Energy Technology Data Exchange (ETDEWEB)

Courtois, G.; Lecomte, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Section des Applications des Radioelements, Centre d' Etudes Nucleaires, Saclay, Station de Recherches Apicoles, Bures-sur-Yvette (France)

1960-07-01

The honeybee, when irradiated by gamma radiations from a cobalt-60 source can stand a 18000 r dose without any apparent harm. Noticeable harm is observed for 90000 r. while immediate death of 100% of the individuals is obtained with a 200000 r dose. The physiological condition of the honeybee plays an important role in its resistance to gamma radiation. Reprint of a paper published in Annales de l'abeille, IV, 1959, p. 285-290 [French] L'Abeille butineuse irradiee par le rayonnement gamma issu d'une source de Cobalt 60 supporte sans dommages apparents une dose de 18000 r. Des dommages tres appreciables sont observes pour 90000 r. Une dose de 200000 r entraine la mort immediate de 100% des individus. L'etat physiologique de l'Abeille joue un role important dans la resistance au rayonnement gamma. Reproduction d'un article publie dans Annales de l'abeille, IV, 1959, p. 285-290.

Gamma radiation effects on photorefractive and photoelectric properties of lithium niobate crystals

Energy Technology Data Exchange (ETDEWEB)

Vartanyan, Eh.S.; Ovsepyan, R.K.; Pogosyan, A.R.; Timofeev, A.L.

1984-08-01

Investigations into the gamma radiation effect on the photorefractive aned photoelectric properties of lithium niobate crystals have been carried out for the first time. Gamma irradiation has been found to lead to an increase in the photorefractive sensitivity. The effect of optical decoloration has been discovered for the first time along with photorelaxation currents resulting from radiation center decay under the action of light. It has been shown that an increase of photorefractive sensitivity in gamma-irradiated lithium niobate crystals is caused by a new photorefraction mechanism - photorelaxation currents.

Mechanism of obtaining carbon monoxide and hydrogen during brown coal radiolysis. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Rustamov, V R; Kurbanov, M A; Dzantiev, B T; Kerimov, V K; Musaeva, P F

1982-05-01

This article analyzes effects of gamma radiation on the yield of products of coal gasification: hydrogen and carbon monoxide. Samples of brown coal from the Kansk-Achins basin were treated by gamma radiation with cobalt 60 radiation source. Analyses show that accumulation of hydrogen and carbon monoxide in brown coal under influence of gamma radiation is characterized by a constant rate. Yields of carbon monoxide and hydrogen amount to 0.16 molecule/100 electro volt and 0.21 molecule/electro volt respectively. Reducing radiation dose from 2.5 to 0.7 millirad/h reduces yields of hydrogen and carbon monoxide. Increasing temperature of vacuum brown coal pyrolysis from 200 to 600 C causes decrease of hydrogen yield. Hydrogen yield decrease during temperature increase is caused by a high content of aromatic nuclei in the samples used in the radiolysis. (5 refs.)

STUDIES CONCERNING THE EFFECT OF GAMMA RADIATION AND MAGNETIC FIELD EXPOSURE ON GLADIOLUS

Directory of Open Access Journals (Sweden)

M CANTOR

2003-04-01

Full Text Available Gladiolus (Gladiolus sp. is one of the most floral species cultivated over in the world and in Romania. There are many studies concerning the effect of gamma radiation on ornamental plants but little is known about the synergetic effect of gamma radiation and exposure to magnetic fields on Gladiolus. In our investigation we have tested the effect of gamma irradiation and magnetic field exposure of gladiolus corms and cormels of the cultivars: Her Majesty, Applause and Speranţa. The corms and cormels were irradiated for 72 hrs with 137 Cs gamma source on cylindrical exposure geometry. At medium dose of 1 Gy has been accumulated for each corm and cormel. For each variety we used 10 corms and 30 cormels in five variants. The comportment of various varieties was evaluated by recording the following characteristics: length of roots and growth tip. Significant effect was obtained at the variants which was irradiated with 1 Gy gamma radiation and 3 Gauss magnetic fields.

Electromagnetic radiation and scattering from small canonical structures of double-negative metamaterials

DEFF Research Database (Denmark)

Arslanagic, Samel

2007-01-01

aspects associated with DNG materials, and was subsequently extended to investigations of the radiation and scattering from two- and three-dimensional (2D and 3D) MTM-based canonical problems in electromagnetic theory. As to the theoretical aspects of DNG materials, the sign, or more generally the branch......, cylindrical and spherical configurations to design electrically small, resonant structures such as cavities, waveguides, scatterers and radiators. These ideas are extended here to canonical antenna and scattering configurations which consist of electrically small resonant cylindrical and spherical MTM......-based structures excited by an arbitrarily located electric line source and an arbitrarily located and oriented electric Hertzian dipole, respectively. Exact analytical solutions, based on eigenfunction series, are derived and then numerically evaluated to study the radiation and scattering from these structures...

Measuring the incombustible content of mine dust using backscatter of low energy gamma rays

International Nuclear Information System (INIS)

Stewart, R.F.; Martin, J.W.

1970-01-01

Low energy gamma radiation directionally applied in a method, and by an adjustable apparatus to a layer of mine dust produces scattered gammas whose reflected radiation detected at a predetermined distance from the mine dust acts to cause the generation of an electrical control input for a meter indicating the incombustible content of the mine dust substantially independently of the effects on such indicating which are normally due to its bulk density and any moisture content thereof. (U.S.)

Gamma radiation effects on different sorts of onions

International Nuclear Information System (INIS)

Burov, B.A.

1977-01-01

Gamma radiation effects on different sorts of onions were studied to improve ways of obtaining agricultural vegetation mutations and to find out the genotype role in induced mutagenesis. It is established that rhizome onion seeds are more radiosensitive than bulbous ones, ephemeroide form seeds are most stable among bulbous plants. Table data on dependence of seed germination and plant survival on radiation dose are presented

Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation.

Science.gov (United States)

Gomes, Tânia; Xie, Li; Brede, Dag; Lind, Ole-Christian; Solhaug, Knut Asbjørn; Salbu, Brit; Tollefsen, Knut Erik

2017-02-01

The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49-1677mGy/h) for 6h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H 2 DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first report on changes in several chlorophyll fluorescence parameters associated with photosynthetic performance and ROS formation in microalgae after exposure to gamma radiation. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of defects in the structure of PIN dosimetry diodes exposed to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Sopko, V. [Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, CZ-18081 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Sopko, B., E-mail: bruno.sopko@cern.ch [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, CZ 16000 Prague 6 (Czech Republic); Faculty of Production Technology and Management, J. E. Purkyně Univerzity in Ústí nad Labem, Na Okraji 1001, 400 01 Ústí nad Labem (Czech Republic); Chren, D. [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, CZ 16000 Prague 6 (Czech Republic); Dammer, J. [Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, CZ-18081 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Charles University in Prague, First Faculty of Medicine, Salmovská 1,CZ-12000 Prague 2 (Czech Republic)

2013-12-01

Studies of radiation induced defects continue to be relevant as they find an ever greater application due to the increasing radiation doses to which semiconductor detectors are exposed. Efforts of figuring out the changes due to high radiation doses provide the fundamental motivation for this type of experiments. The PIN diode is described, and a developmental disorder caused thereto by 60Co source gamma quanta ranging from 100 kGy to 1 MGy. The calibration curve shows the effect of disturbances on the volt-ampere characteristics as a function of the dose of gamma radiation. The results are compared with earlier published data. Highlights: •We have studied Si PIN diode dosimeters irradiated by gamma. •We measured DLTS spectra and calculated energy traps caused by gamma irradiation. •Increasing dose caused creation of new traps and disappearance of others.

Effects of chronic gamma radiation on the lichen Parmelia sulcata Tayl. in the Enterprise Radiation Forest

International Nuclear Information System (INIS)

Erbisch, F.H.

1977-01-01

Within the Enterprise Radiation Forest, the foliose lichen Parmelia sulcata Tayl. exhibited radiation damage. Only those lichens which received in excess of 100 krad manifested damage. The damage was evidenced as a lifting and subsequent breaking of lobes, a coalescing of fungal hyphae, a formation of a brown pigment by the coalescing hyphae, a distortion of the chloroplastid of the algal component, and eventual death of the lichen. The radiation also affected thallus growth by slowing it and rhizinae branching by increasing the number of branches. Damage was not manifested until the late spring (June) of the year following radiation. Apparently P. sulcata is able to maintain itself until conditions are favorable for growth, after receiving a large dose of gamma radiation. Under favorable growth conditions, the lichen cannot carry out its normal growth functions and deteriorates. Although environmental changes did occur within the forest, evidence obtained indicates that gamma radiation was the principal factor affecting the lichens

Dose rate on the environment generated by a gamma irradiation plant

International Nuclear Information System (INIS)

Mangussi, J.

2011-01-01

A model for the absorbed dose rate calculation on the surroundings of a gamma irradiation plant is developed. In such plants, a part of the radiation emitted upwards reach the outdoors. The Compton scatterings on the wall of the exhausting pipes through de plant roof and on the outdoors air are modelled. The absorbed dose rate generated by the scattered radiation reaching the outdoors floor is calculated. The results of the models, to be used for the irradiation plant design and for the environmental studies, are showed on tables and graphics. (author) [es

Effect of ionizing (gamma and non-ionizing (UV radiation on the development of Trichogramma euproctidis (Hymenoptera: Trichogrammatidae

Directory of Open Access Journals (Sweden)

Tuncbilek Aydin S.

2012-01-01

Full Text Available The potential of using gamma and ultraviolet radiation as an alternative treatment to increase the efficiency of Trichogramma euproctidis (Girault 1911 (Hymenoptera: Trichogrammatidae was investigated in the laboratory. The developmental and adult stages of T. euproctidis were exposed to gamma radiation of different doses (0-30 Gy and ultraviolet radiation of 254 nm wavelengths (UV-C for different durations (0-10 min to assess their effect on each of the instars and their potential in breaking the developmental cycle of the egg parasitoid. The LD50 values for eggs, prepupae, pupae and adults were 8.1, 10.0, 22.7 and 9.5 Gy for gamma radiation and 9.5, 0.12, 2.0 and 11.9 min for UV radiation, respectively. The pupa and adult stages were more radioresistant to both gamma and UV radiation. The most interesting and unexpected result obtained for the prepupal stage was that UV radiation has a greater effect on prepupal stages than gamma radiation.

Investigations on insect disinfestation of dried dates by using gamma radiation

International Nuclear Information System (INIS)

Ahmed, M.S.H.

1981-01-01

Reviews the laboratory experiments carried out in Iraq to control the most important insect pests of dates in storage, viz. the fig moth, Ephestia cautella and the saw-toothed grain beetle, oryzaephilus surinamensis by gamma-radiation. Developmental stages of Ecutella in general had a much higher resistance to gamma-radiation than the corresponding stages of O-surinamensis. Treatment with a dose of 20 Krad resulted in 100 mortality in the most damaging developmental stages of the species. (46 refs.)

Titanium-Water Thermosyphon Gamma Radiation Exposure and Results

Science.gov (United States)

Sanzi, James, L.A; Jaworske, Donald, A.; Goodenow, Debra, A.

2012-01-01

Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some gamma irradiation. Noncondensable gas formation from radiation-induced breakdown of water over time may render portions of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature under accelerated gamma irradiation, with exposures on the same order of magnitude as that expected in 8 years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon: evaporator, condenser, and condenser end cap. Some noncondensable gas was evident; however, thermosyphon performance was not affected because the noncondensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of noncondensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the noncondensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of one thermosyphon in a vacuum chamber and at temperature revealed that the noncondensable gas diffused out of the thermosyphon over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

Titanium-Water Thermosyphon Gamma Radiation Effects and Results

Science.gov (United States)

Sanzi, James L.; Jaworske, Donald A.; Goodenow, Debra A.

2012-01-01

Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some exposure to gamma irradiation. Non-condensable gas formation from radiation may breakdown water over time and render a portion of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature with accelerated gamma irradiation exposures on the same order of magnitude that is expected in eight years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon; evaporator, condenser, and condenser end cap. Some non-condensable gas was evident, however thermosyphon performance was not affected because the non-condensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of non-condensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the non-condensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of selected thermosyphons at temperature and in a vacuum chamber revealed that the non-condensable gas likely diffused out of the thermosyphons over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

Preservation of photographic and cinematographic films by gamma radiation: Preliminary analyses

Energy Technology Data Exchange (ETDEWEB)

Nagai, Maria Luiza E.; Santos, Paulo S.; Otubo, Larissa; Oliveira, Maria José A.; Vasquez, Pablo A.S., E-mail: malunagai@usp.br, E-mail: pavsalva@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

Brazilian weather conditions affect directly tangible materials causing deterioration notably getting worse by insects and fungi attack. In this sense, gamma radiation provided from the cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because it has biocidal action. Radiation processing using gamma radiation for cultural heritage materials for disinfection has been widely used around the world in the last decades. Many cultural heritage objects especially made on paper and wood were studied in scientific publications aiming mechanical, physical and chemical properties changes. Over the last fifteen years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute located inside the Sao Paulo University campus has been irradiated many collections of archived materials, books, paintings and furniture. Adequate storage of photographic and cinematographic materials is a challenge for conservators from preservation institutions. Contamination by fungi is one of leading causes of problem in photographic and cinematographic collections. Several Sao Paulo University libraries have been affected by fungi in their photographic and cinematographic collections making it impossible to research on these materials either manipulate them for health and safety reasons. In this work are presented preliminary results of effects of the ionizing radiation in photographic and cinematographic films. Selected film samples made on cellulose acetate were prepared and characterized by FTIR-ATR spectroscopy. Samples were irradiated by gamma rays with absorbed dose between 2 kGy and 50 kGy. Irradiated samples were analyzed by UV-VIS spectroscopy and electron microscopy techniques. Results shown that disinfection by gamma radiation can be achieved safely applying the disinfection dose between 6 kGy to 15 kGy with no significant change or modification of main properties of the constitutive materials. (author)

Preservation of photographic and cinematographic films by gamma radiation: Preliminary analyses

International Nuclear Information System (INIS)

Nagai, Maria Luiza E.; Santos, Paulo S.; Otubo, Larissa; Oliveira, Maria José A.; Vasquez, Pablo A.S.

2017-01-01

Brazilian weather conditions affect directly tangible materials causing deterioration notably getting worse by insects and fungi attack. In this sense, gamma radiation provided from the cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because it has biocidal action. Radiation processing using gamma radiation for cultural heritage materials for disinfection has been widely used around the world in the last decades. Many cultural heritage objects especially made on paper and wood were studied in scientific publications aiming mechanical, physical and chemical properties changes. Over the last fifteen years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute located inside the Sao Paulo University campus has been irradiated many collections of archived materials, books, paintings and furniture. Adequate storage of photographic and cinematographic materials is a challenge for conservators from preservation institutions. Contamination by fungi is one of leading causes of problem in photographic and cinematographic collections. Several Sao Paulo University libraries have been affected by fungi in their photographic and cinematographic collections making it impossible to research on these materials either manipulate them for health and safety reasons. In this work are presented preliminary results of effects of the ionizing radiation in photographic and cinematographic films. Selected film samples made on cellulose acetate were prepared and characterized by FTIR-ATR spectroscopy. Samples were irradiated by gamma rays with absorbed dose between 2 kGy and 50 kGy. Irradiated samples were analyzed by UV-VIS spectroscopy and electron microscopy techniques. Results shown that disinfection by gamma radiation can be achieved safely applying the disinfection dose between 6 kGy to 15 kGy with no significant change or modification of main properties of the constitutive materials. (author)

Gamma radiation and chickens

International Nuclear Information System (INIS)

Toropilova, D.; Takac, L.; Toropila, M.; Tomko, M. M.

2014-01-01

In our work, we focused the effect of low doses of gamma radiation on metabolic parameters in chickens. In the first group of chickens we monitor changes of the concentration in glucose and cholesterol after whole body irradiation dose of chicken (3 Gy). In the second group of chickens we studied the combined effect of radiation and intraperitoneal application solution of zinc chloride to changes of the concentration in glucose and total cholesterol. In the tissues of organisms are found only in a very small amount of microelements however are of particular importance in a number of enzymatic catalytic and regulatory processes. Zinc is found in all cells of the body. However, it is the highest percentage of zinc contained in muscle and bone cells. Resorption takes place in the small intestine, especially in the duodenum. For both groups of chickens, we performed analyzes on the 3 rd , 7 th , 14 th , 21 st and 30 day. Results and an overview of the work can be helpful in the peaceful uses of nuclear energy and in preventing diseases from exposure to radiation, but also in the case of the consequences after nuclear accidents. (authors)

A comparison of ionizing radiation damage in CMOS devices from 60Co gamma rays, electrons and protons

International Nuclear Information System (INIS)

He Baoping; Yao Zhibin; Zhang Fengqi

2009-01-01

Radiation hardened CC4007RH and non-radiation hardened CC4011 devices were irradiated using 60 Co gamma rays, 1 MeV electrons and 1-9 MeV protons to compare the ionizing radiation damage of the gamma rays with the charged particles. For all devices examined, with experimental uncertainty, the radiation induced threshold voltage shifts (ΔV th ) generated by 60 Co gamma rays are equal to that of 1 MeV electron and 1-7 MeV proton radiation under 0 gate bias condition. Under 5 V gate bias condition, the distinction of threshold voltage shifts (ΔV th ) generated by 60 Co gamma rays and 1 MeV electrons irradiation are not large, and the radiation damage for protons below 9 MeV is always less than that of 60 Co gamma rays. The lower energy the proton has, the less serious the radiation damage becomes. (authors)

The simple analytical method for scattered radiation calculation in contrast X-ray diagnostic techniques

Energy Technology Data Exchange (ETDEWEB)

Markovic, S; Pavlovic, R [Inst. of Nuclear Science Vinca, Belgrade (Yugoslavia). Radiation and Environmental Protection Lab.; Boreli, F [Fac. of Electrical Engineering, Belgrade (Yugoslavia)

1996-12-31

In realization of radiation protection measures for medical staff present during diagnostic procedures, the necessary condition is knowledge of the space - energy distributions of the scattered radiation from the patient. In this paper, the simple calculation procedure for the scattered radiation field of the actual diagnostic energies is presented. Starting from the single Compton scattering model and using the justified transformations the final equations in elementary form are derived. For numerical calculations the computer code ANGIO was created. The calculated results were confirmed by detailed dosimetric measurements of the scattered field around patient (the water phantom) in SSDL in the Institute of nuclear sciences `Vinca`, Belgrade. These results are good base for assessment of irradiation. The main irradiation source for the physician and the other members of the medical team is the back scattered radiation from patient - albedo. (author). 3 figs., 3 refs.

Radiation scatter apparatus and method

International Nuclear Information System (INIS)

Molbert, J. L.; Riddle, E. R.

1985-01-01

A radiation scatter gauge includes multiple detector locations for developing separate and independent sets of data from which multiple physical characteristics of a thin material and underlying substrate may be determined. In an illustrated embodiment, the apparatus and method of the invention are directed to determining characteristics of resurfaced pavement by nondestructive testing. More particularly, the density and thickness of a thin asphalt overlay and the density of the underlying pavement may be determined

A method to describe inelastic gamma field distribution in neutron gamma density logging.

Science.gov (United States)

Zhang, Feng; Zhang, Quanying; Liu, Juntao; Wang, Xinguang; Wu, He; Jia, Wenbao; Ti, Yongzhou; Qiu, Fei; Zhang, Xiaoyang

2017-11-01

Pulsed neutron gamma density logging (NGD) is of great significance for radioprotection and density measurement in LWD, however, the current methods have difficulty in quantitative calculation and single factor analysis for the inelastic gamma field distribution. In order to clarify the NGD mechanism, a new method is developed to describe the inelastic gamma field distribution. Based on the fast-neutron scattering and gamma attenuation, the inelastic gamma field distribution is characterized by the inelastic scattering cross section, fast-neutron scattering free path, formation density and other parameters. And the contribution of formation parameters on the field distribution is quantitatively analyzed. The results shows the contribution of density attenuation is opposite to that of inelastic scattering cross section and fast-neutron scattering free path. And as the detector-spacing increases, the density attenuation gradually plays a dominant role in the gamma field distribution, which means large detector-spacing is more favorable for the density measurement. Besides, the relationship of density sensitivity and detector spacing was studied according to this gamma field distribution, therefore, the spacing of near and far gamma ray detector is determined. The research provides theoretical guidance for the tool parameter design and density determination of pulsed neutron gamma density logging technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gamma-ray detectors for intelligent, hand-held radiation monitors

International Nuclear Information System (INIS)

Fehlau, P.E.

1983-01-01

Small radiation detectors based on HgI 2 , bismuth germanate (BGO), plastic, or NaI(Tl) detector materials were evaluated for use in small, lighweight radiation monitors. The two denser materials, HgI 2 and BGO, had poor resolution at low-energy and thus performed less well than NaI(Tl) in detecting low-energy gamma rays from bare, enriched uranium. The plastic scintillator, a Compton recoil detector, also performed less well at low gamma-ray energy. Two small NaI(Tl) detectors were suitable for detecting bare uranium and sheilded plutonium. One became part of a new lightweight hand-held monitor and the other found uses as a pole-mounted detector for monitoring hard-to-reach locations

Effects of gamma radiation in vitro culture on protocorm development of dendrobium pattaya beauty

International Nuclear Information System (INIS)

Flores, John Martin R.; Lanic, Alvin D.; Matuto, Mark Anthony C.; Vidal, John Faustus C.

2006-01-01

This study sought to determine if gamma radiation had an efect on in-vitro cultured orchids in its regeneration of a protocorm into plantlet within 20 days duration. To find the effects of gamma radiation in terms of weight development, the method used was experimental procedure. The design used in this study was Random Complete Block Design. The researchers used dendrobium pattaya beauty as a subject of the study. Applying gamma radiation to change the maturing time of the protocorm. The researchers' findings about the study shows that the average weights increase of each treatment/s in the three (3) data observation after inoculation vary from sample to sample. As can be seen in the table that the average weight increase of dendrobium pattaya beauty protocorm does not have an obvious trend considering the increase of gamma radiation on the diferent treatments. It can be seen that the converted f average of 1.5 is lower than the critical f value of 4.07 at 0.05 level of significance with the degree s of freedom of 3/8. The null hypothesis stating that gamma radiation has no effects on the weight of dendrobium pattaya beauty protocorm is accepted. Therefore the researchers concluded, that out of the eight (8) samples the general average weight increase for the control (1.01 grams), 30 Gy (1.22 grams), 50 Gy (1.06 grams), 70 Gy (0.44 grams). Hence, it can be concluded that the radiation does not show positive effect on the weight of dendrobium pattaya beauty protocorm. One-way Anova shows that there is no significant effect on the weight of dendrobium protocorm. The researchers recommend that dendrobium pattaya beauty is a good example of plant, to have undergone this kind of experiment. The researchers also recommend that gamma radiation would not affect the growth of the protocorm upon the result of one-way Anova that there is no significance using gamma radiation. The researchers would like to recommend continuing this study, from embryo to complete plantlet

Measuring stations for gamma radiation - measured results 1982

International Nuclear Information System (INIS)

Kjelle, P.E.

1983-01-01

Gamma radiation is recorded continuously at 25 stations in Sweden. The evaluation of the data from five of the stations is made in a most accurate way, and the results are presented in this report. (G.B.)

Effects of 60Co gamma radiation on crotamine

Directory of Open Access Journals (Sweden)

Boni-Mitake M.

2001-01-01

Full Text Available Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide (pI 10.3 from Crotalus durissus terrificus venom composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated crotamine. Crotamine was purified from C.d. terrificus venom by Sephadex G-100 gel filtration followed by ion-exchange chromatography, and irradiated at 2 mg/ml in 0.15 M NaCl with 2.0 kGy gamma radiation emitted by a 60Co source. The native and irradiated toxins were evaluated in terms of structure and toxic activity (LD50. Irradiation did not change the protein concentration, the electrophoretic profile or the primary structure of the protein although differences were shown by spectroscopic techniques. Gamma radiation reduced crotamine toxicity by 48.3%, but did not eliminate it.

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.

Gamma radiation and HZE treatment of seedlings in Arabidopsis

Data.gov (United States)

National Aeronautics and Space Administration — Plants exhibit a robust transcriptional response to gamma radiation which includes the induction of transcripts required for homologous recombination and the...

Influence of gamma radiation onto polymeric matrix with papain

International Nuclear Information System (INIS)

Zulli, Gislaine; Lopes, Patricia Santos; Velasco, Maria Valeria Robles; Alcantara, Mara Tania Silva; Rogero, Sizue Ota; Lugao, Ademar Benevolo; Mathor, Monica Beatriz

2010-01-01

Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed; the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied.

Physiological quality of rice seed submitted to gamma radiation

International Nuclear Information System (INIS)

Miranda, Helen Lucia da Cruz; Tillmann, Maria Angela Andre; Meneghello, Geri Eduardo

2009-01-01

The objective of this research was to evaluate the effects of the gamma radiation ( 60 Co) on the physiological quality of rice seeds. The research was carried out through three tests; in the first test rice seeds were irradiated at dosages of 0; 1; 2.5 and 5Gy, while for the second and third tests the seeds were subjected to accelerated aging before being irradiated. For the second test the seeds were divided into wet and dry and both groups subjected to accelerated aging previous to irradiation at dosages of 0; 1; 2.5 and 5Gy. For the third test the seeds were dried after being subjected to accelerated aging, and then irradiated at dosages of 0, 10, 25 and 50Gy. To assess the physiological effects of the gamma radiation, all seeds were tested for germination and their germination speed index recorded. Seedling growth was graded through the measurement of the lengths of the first leaf and seminal root system and total seedling dry weight, across all tests. The enzymatic activity of acid phosphatase and alpha-amylase was measured on dry seeds from the second test. The results from all tests indicate that the applied gamma radiation dosages did not cause any changes to the physiological quality of rice seeds. (author)

Influence of gamma radiation onto polymeric matrix with papain

Energy Technology Data Exchange (ETDEWEB)

Zulli, Gislaine [Nuclear and Energetic Research Institute, IPEN-CNEN/SP, Sao Paulo, SP 05508-000 (Brazil); Lopes, Patricia Santos, E-mail: patricia.lopes@prof.uniso.b [Pharmacy Department, University of Sorocaba, Sorocaba, SP 18023-000 (Brazil); Velasco, Maria Valeria Robles [Pharmacy Department, University of Sao Paulo, Sao Paulo, SP 05508-900 (Brazil); Alcantara, Mara Tania Silva; Rogero, Sizue Ota; Lugao, Ademar Benevolo; Mathor, Monica Beatriz [Nuclear and Energetic Research Institute, IPEN-CNEN/SP, Sao Paulo, SP 05508-000 (Brazil)

2010-03-15

Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed; the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied.

Influence of gamma radiation onto polymeric matrix with papain

Science.gov (United States)

Zulli, Gislaine; Lopes, Patrícia Santos; Velasco, Maria Valéria Robles; Alcântara, Mara Tânia Silva; Rogero, Sizue Ota; Lugao, Ademar Benévolo; Mathor, Monica Beatriz

2010-03-01

Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed; the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied.

Effect of temperature and gamma radiation on pupae of tenebrio molitor LINNE

International Nuclear Information System (INIS)

Arthur, Valter; Arthur, Paula Bergamin

2001-01-01

Among insect pests of grains and stored products Tenebrio molitor (Coleoptera : Tenebriodae) is one of the species of insects that attack flours, corn meal, rations, macaronis and damages grains. Chemical treatment is not always the remedy because it causes problems of residue on treated food. One alternative method of control is the application of ionization radiations as suggested by Hunter, some others recommended the use of gamma radiation to control insects that attack grains and stored products. Arthur and Wiendl reported that the sterilizing dose to adults of this species is 60 Gy. The effect of temperature after and before the gamma radiation to Laemophleous spp. Zabrotes subfasciatus and Sitophilus oryzae has been studied by many workers. Since no study with radiological effects in combination with temperature is reported on T. molitor, research work has been carried out to study the synergistic effects of gamma radiation and temperature on pupae of this insect

Application of Glycine-TTC dosimeter in gamma radiation processing facility

International Nuclear Information System (INIS)

Shinde, S.H.; Mondal, S.; Kulkarni, M.S.

2018-01-01

Glycine-TTC dosimeter was found to have a useful dose range of 5 to 30 kGy using spectro-photometric read-out method. Potential use of this dosimeter was demonstrated by measuring dose-rate in gamma chamber GC 900. The aim of the present study was to verify the performance of this dosimeter in actual industrial processing conditions encountered in radiation processing facility such as Gamma Radiation Processing Plant for Spices (GRPPS), BRIT, Vashi. Accordingly, glycine-TTC dosimeters were irradiated along with routine dosimeter viz. ceric-cerous of GRPPS and reference standard dosimeter viz. alanine EPR

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

CERN Document Server

Bratchenko, M I; Rozhkov, V V

2001-01-01

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

Gamma radiation sterilises bacteria-contaminated waste

International Nuclear Information System (INIS)

Anon.

1978-01-01

The use of gamma radiation for the sterilisation of sewage and hospital waste etc., is briefly described. A sterilisation plant delivered by Sulzer is illustrated diagrammatically and its functioning explained, while a photograph illustrates a similar plant delivered by Geodel Systems, of Canada. The latter firm has adapted this type of plant for the radiolytical destruction of phenols, cyanides, alkyl benzenesulphonates and similar wastes. (JIW)

Polarization effects in coherent and incoherent photon scattering: survey of measurements and theory relevant to radiation transport calculations

International Nuclear Information System (INIS)

Hubbell, J.H.

1993-01-01

This report reviews available information on polarization effects arising when photons in the X-ray and gamma-ray energy regime undergo coherent (Rayleigh) scattering and incoherent (Compton) scattering by atomic electrons. In addition to descriptions and discussions of these effects, including estimates of their magnitudes as they apply to radiation transport calculations, an annotated bibliography of 102 selected works covering the period 1905-1991 is provided, with particularly relevant works for the purpose of this report flagged with asterisks (*). A major resource for this report is a 1948 unpublished informal report by L.V. Spencer which has been quoted here almost in its entirety, since, of all the works cited in the annotated bibliography, it appears to be the only one which explicitly and directly addresses the purpose of this report. Hence this valuable material should be re-introduced into the available and current literature. (author). 119 refs., 7 figs

OBSERVATIONAL SIGNATURES OF SUB-PHOTOSPHERIC RADIATION-MEDIATED SHOCKS IN THE PROMPT PHASE OF GAMMA-RAY BURSTS

International Nuclear Information System (INIS)

Levinson, Amir

2012-01-01

A shock that forms below the photosphere of a gamma-ray burst (GRB) outflow is mediated by Compton scattering of radiation advected into the shock by the upstream fluid. The characteristic scale of such a shock, a few Thomson depths, is larger than any kinetic scale involved by several orders of magnitude. Hence, unlike collisionless shocks, radiation-mediated shocks cannot accelerate particles to nonthermal energies. The spectrum emitted by a shock that emerges from the photosphere of a GRB jet reflects the temperature profile downstream of the shock, with a possible contribution at the highest energies from the shock transition layer itself. We study the properties of radiation-mediated shocks that form during the prompt phase of GRBs and compute the time-integrated spectrum emitted by the shocked fluid following shock breakout. We show that the time-integrated emission from a single shock exhibits a prominent thermal peak, with the location of the peak depending on the shock velocity profile. We also point out that multiple shock emission can produce a spectrum that mimics a Band spectrum.

Radiation protection in category III large gamma irradiators

International Nuclear Information System (INIS)

Costa, Neivaldo; Furlan, Gilberto Ribeiro; Itepan, Natanael Marcio

2011-01-01

This article discusses the advantages of category III large gamma irradiator compared to the others, with emphasis on aspects of radiological protection, in the industrial sector. This category is a kind of irradiators almost unknown to the regulators authorities and the industrial community, despite its simple construction and greater radiation safety intrinsic to the model, able to maintain an efficiency of productivity comparable to those of category IV. Worldwide, there are installed more than 200 category IV irradiators and there is none of a category III irradiator in operation. In a category III gamma irradiator, the source remains fixed in the bottom of the tank, always shielded by water, negating the exposition risk. Taking into account the benefits in relation to radiation safety, the category III large irradiators are highly recommended for industrial, commercial purposes or scientific research. (author)

Inverse Compton gamma-rays from pulsars

International Nuclear Information System (INIS)

Morini, M.

1983-01-01

A model is proposed for pulsar optical and gamma-ray emission where relativistic electrons beams: (i) scatter the blackbody photons from the polar cap surface giving inverse Compton gamma-rays and (ii) produce synchrotron optical photons in the light cylinder region which are then inverse Compton scattered giving other gamma-rays. The model is applied to the Vela pulsar, explaining the first gamma-ray pulse by inverse Compton scattering of synchrotron photons near the light cylinder and the second gamma-ray pulse partly by inverse Compton scattering of synchrotron photons and partly by inverse Compton scattering of the thermal blackbody photons near the star surface. (author)

Gamma radiation effects on rice, substrate for Sitophilus oryzae (L.) rearing

International Nuclear Information System (INIS)

Wiendl, F.M.; Arthur, V.; Walder, J.M.M.; Domarco, R.E.

1987-01-01

The gamma radiation effects (800 Krad, 60 Co) on rice are studied. Degraded substances by the radiation and how this degradation affects the biology of Sitophilus oryzae (L.) are searched. The vitamins, proteins and stard of the rice are affected by the radiation. (M.A.C.) [pt

Incoherent scattering functions of 145 keV gamma rays by K-shell electrons in Y, Ag and Au

International Nuclear Information System (INIS)

Raghava Rao, A.; Ramana Reddy, S.V.S.; Premchand, K.; Narasimham, K.L.; Parthasaradhi, K.; Lakshminarayana, V.

1982-01-01

The values of incoherent scattering functions are determined experimentally for 145 keV gamma rays in elements Au, Ag and Y at scattering angles 40 0 , 70 0 and 100 0 , using a x-ray gamma coincidence technique. The corresponding theoretical values are obtained from the tabulations of Hubbell et al, and computed from the models of Jauch and Rohrlich and Shimizu et al. A comparison between the theoretical and experimental results showed that the non-relativistic approach adopted in the theory of Shimizu et al is inapplicable to the present cases. A gross agreement is noticed between the present experimental results and the other theoretical values. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Protective role of radish oil (raphson sativus) against gamma radiation on lipids and carbohydrate in male rats

International Nuclear Information System (INIS)

Omran, M.F.; Soliman, N.K.I.

2005-01-01

The present work was carried out to investigate the effects of ionizing radiation on some biochemical parameters in rats. The rats were exposed to sublethal whole body gamma irradiation dose (1Gy x 4). The protective role of radish oil (Raphanus sativus) was evaluated by oral administration to rats before gamma radiation exposure and the lipid profile, serum glucose and liver glycogen were investigated. Exposed rats to gamma radiation showed significant alterations in the assayed parameters indicating disturbances in lipid and carbohydrate metabolisms. Oral administration of radish oil (Raphanus sativus) before gamma irradiation exerted marked ameliorations in the disorders induced by gamma radiation in most of the tested parameters such as lipid profile, serum glucose and liver glycogen

Scatter radiation in digital tomosynthesis of the breast

International Nuclear Information System (INIS)

Sechopoulos, Ioannis; Suryanarayanan, Sankararaman; Vedantham, Srinivasan; D'Orsi, Carl J.; Karellas, Andrew

2007-01-01

Digital tomosynthesis of the breast is being investigated as one possible solution to the problem of tissue superposition present in planar mammography. This imaging technique presents various advantages that would make it a feasible replacement for planar mammography, among them similar, if not lower, radiation glandular dose to the breast; implementation on conventional digital mammography technology via relatively simple modifications; and fast acquisition time. One significant problem that tomosynthesis of the breast must overcome, however, is the reduction of x-ray scatter inclusion in the projection images. In tomosynthesis, due to the projection geometry and radiation dose considerations, the use of an antiscatter grid presents several challenges. Therefore, the use of postacquisition software-based scatter reduction algorithms seems well justified, requiring a comprehensive evaluation of x-ray scatter content in the tomosynthesis projections. This study aims to gain insight into the behavior of x-ray scatter in tomosynthesis by characterizing the scatter point spread functions (PSFs) and the scatter to primary ratio (SPR) maps found in tomosynthesis of the breast. This characterization was performed using Monte Carlo simulations, based on the Geant4 toolkit, that simulate the conditions present in a digital tomosynthesis system, including the simulation of the compressed breast in both the cranio-caudal (CC) and the medio-lateral oblique (MLO) views. The variation of the scatter PSF with varying tomosynthesis projection angle, as well as the effects of varying breast glandular fraction and x-ray spectrum, was analyzed. The behavior of the SPR for different projection angle, breast size, thickness, glandular fraction, and x-ray spectrum was also analyzed, and computer fit equations for the magnitude of the SPR at the center of mass for both the CC and the MLO views were found. Within mammographic energies, the x-ray spectrum was found to have no appreciable

Study of stability of chloramphenicol in different forms to gamma radiation

International Nuclear Information System (INIS)

Tawfik, Z.S.

1985-01-01

The effect of radiation dose, in the range from 5 KGY to 250 KGY, on chloramphenicol in either the solid form or as aqueous solution was studied. The results obtained showed that the radiation had no effect on the antibiotic when it was irradiated in the solid form. Minor changes were detected when the antibiotic was exposed to radiation in solution, at doses as small as 5 KGY. These changes were detected by UV-visible, infrared and HPLC techniques. Bioassay experiments performed using the antibiotic concentration recommended by pharmacopoeia were not sensitive enough to detect these small changes. Lower concentrations of the studied antibiotic in the chloramphenicol as a result of exposure to radiation in solution or as eye drops. Accordingly, sterilization of chloramphenicol using gamma radiation could be considered a safe process if the antibiotic is in the solid form but aqueous solutions of the studied antibiotic are not recommended for sterilization by gamma radiation. (author)

Effects of gamma radiation on lichens and lichen-forming fungi and algae

International Nuclear Information System (INIS)

Erbisch, F.H.

1977-06-01

Initial literature reports indicated that lichens were highly resistant to gamma radiation. A series of experiments were undertaken to determine why lichens were so resistant. In experiments with Cladonia mitis, C. sylvatica, C. verticillata, Parmelia sulcata and P. subaurifera, using both acute and chronic radiation, it was found that these lichens were not highly resistant to gamma radiation. The lichens appeared to be resistant as long as they were in a dormant condition. But, when allowed to pass through a period which was suitable for growth, radiation damage was quickly manifested. Radiation damage was seen in various ways, including the change of thallus color, disintegration of phycobiant chloroplastids, coalescing of fungal hyphae, reduced CO 2 uptake, and reduction in thallus tensile strength

Measuring main-ion temperatures in ASDEX upgrade using scattering of ECRH radiation

DEFF Research Database (Denmark)

Pedersen, Morten Stejner; Nielsen, Stefan Kragh; Jacobsen, Asger Schou

2016-01-01

We demonstrate that collective Thomson scattering of millimeter wave electron cyclotron resonance heating radiation can be used for measurements of the main-ion temperature in the ASDEX Upgrade tokamak.......We demonstrate that collective Thomson scattering of millimeter wave electron cyclotron resonance heating radiation can be used for measurements of the main-ion temperature in the ASDEX Upgrade tokamak....

A non-destructive technique for assigning effective atomic number to scientific samples by scattering of 59.54 keV gamma photons

International Nuclear Information System (INIS)

Singh, M.P.; Sharma, Amandeep; Singh, Bhajan; Sandhu, B.S.

2010-01-01

The objective of present experiment, employing a scattering of 59.54 keV gamma photons, is to assign effective atomic number (Z eff ) to scientific samples (rare earths) of known composition. An HPGe semiconductor detector, placed at 90 o to the incident beam, detects gamma photons scattered from the sample under investigation. The experiment is performed on various elements with atomic number satisfying, 6≤Z≤82, for 59.54 keV incident photons. The intensity ratio of Rayleigh to Compton scattered peaks, corrected for photo-peak efficiency of gamma detector and absorption of photons in the sample and air, is plotted as a function of atomic number and constituted a best fit-curve. From this fit-curve, the respective effective atomic numbers to samples of rare earths are determined. The agreement of measured values of Z eff with theoretical calculations is quite satisfactory.

Effect of glucocorticoids and gamma radiation on epidermal Langerhans cells

International Nuclear Information System (INIS)

Belsito, D.V.; Baer, R.L.; Thorbecke, G.J.; Gigli, I.

1984-01-01

The effect of 750 rads of gamma radiation on the rate of return of epidermal Langerhans cells (LC) following suppressive doses of topical glucorticoids was studied in guinea pigs. Gamma radiation alone had no effect on the LC as assessed by staining for cell membrane ATPase activity and Ia antigen. It did, however, delay the expected return of Ia but not ATPase surface markers on the LC after perturbation with glucocorticoids. The delayed return of surface Ia antigen is possibly related to a radiation-induced defect in the production of a required lymphokine and/or in intracellular Ia transport. Although our data do not rule out a cytolytic effect of steroids on the LC, they do strongly suggest that, at least in part, glucocorticoids act on the LC by altering cell surface characteristics

Investigations on image improvement in radiodiagnosis under special consideration of reducing scattered radiation

International Nuclear Information System (INIS)

Becker, R.

1976-10-01

In the study, image improvement is proposed for scintiscanning, X-ray and neutron diagnosis as well as computer axial tomography. In order to reduce the scattered radiation, mainly two-dimensional radiation transport calculations are carried out, and the imaging properties are studied by simulation on a large computer. It was found, among other things, that in contrast to X-ray techniques, in diagnosis with fast neutrons the image quality can hardly be improved by screens for scattered radiation. Here the problem of scattered radiation can only be solved by using scanners with narrow beams. The new method of neutron diagnosis resulting from this is especially suited for representing structures behind bones or for the localization of bone tumors invisible to X-rays, but not for representing fatty tissue. For large depths of irradiation, the scattered radiation with neutron sources below 1 MeV gets so intensive that diagnosis becomes impossible. When fast neutrons are used are used, the method is applicable for computer axial tomography because of the narrow beams. (ORU) [de

The gamma-ray radiation preservation technology for files and books

International Nuclear Information System (INIS)

Fan Chengfa; Tian Kaizen; Zhang Yunlu; Gan Saohan; Wang Zhengfu; Xiang Jiafang

1988-01-01

In this paper, a radiation appliance using CO-60 Gamma-ray to preserve the files and books is introduced. The lump and transport radiation techniques for processing files and books with this radiation appliance is described. The cost of preserving files and books with this method has been estimated. Comparison of this method with other processing techniques has been taken. (author)

Gamma radiation sterilization of Bactrocera invadens (Diptera ...

African Journals Online (AJOL)

The African invader fly, Bactrocera invadens, an invasive pest in Africa since 2003, causes damage and poses a threat to the mango and horticultural industry. Its control is therefore needed. Sterilization of males using gamma radiation doses (25, 50 and 75 Gy) as a means of population control was investigated. Irradiation ...

Effect of ionizing radiations on bacterial endotoxins: comparison between gamma radiations and accelerated electrons

Energy Technology Data Exchange (ETDEWEB)

Guyomard, S; Goury, V; Darbord, J C

1988-01-01

Determinations of the effect of radiation sterilization processing on purified endotoxins, in aqueous solution or on dried support, are reported. These observations allow us to accept gamma radiations for sterilization of parenteral devices with an estimated probability of existence of non apyrogenic items, based upon a similar definition of the usual Sterility Assurance Level (SAL = 10/sup -6/).

Inactivation of rabies diagnostic reagents by gamma radiation

International Nuclear Information System (INIS)

Gamble, W.C.; Chappell, W.A.; George, E.H.

1980-01-01

Treatment of CVS-11 rabies adsorbing suspensions and street rabies infected mouse brains with gamma radiation resulted in inactivated reagents that are safer to distribute and use. These irradiated reagents were as sensitive and reactive as the nonirradiated control reagents

Effect of Gamma Radiation on Nutritional Indices of Larval and Adults Stages of Tribolium castaneum (Coleoptera: Tenebrionidae)

International Nuclear Information System (INIS)

Ahmadi, M.; Moharramipour, S.

2012-01-01

In this study antifeedant effect of different doses of gamma radiation as a controlling safe method on flour weevil, Tribolium castaneum (Herbst) larvae and adult was studied. Doses of 100, 400, 600, 800 and 1000 Gy of gamma radiation were used and after 72 hours, nutritional indices were evaluated. The relative growth rate, relative consumption rate, efficiency of conversion of ingested food and feeding deterrence index as nutritional indices were evaluated. Treatments were assessed by flour wheat disc at 27±1 d egree C and 65 p ercent h umidity in a dark condition. The results showed that the relative growth rate of flour weevil larvae and adults decreased significantly (P<0.05) by gamma radiation and the severity of this reduction in larvae was higher than the adults. Although the relative growth rates decreased in adults, this rate in doses of 400, 600, 800 and 1000 Gy showed no significant difference. The relative food consumption rate also decreased with the gamma radiation and its value found to be inversely proportional to the dose radiation. Our experiments showed that the use of gamma radiation exposure to 800 Gy had no significant effect on the efficiency of conversion of ingested food of larvae and reduction was observed only when the gamma radiation was used in 1000 Gy. The feeding deterrence effect of gamma radiation, especially on the larvae was high but no significant difference between doses of 100 to 800 Gy was observed. The results showed that gamma radiation that induces antifeedant effect can be applied as an effective method in control of T. castaneum.

Characterization of the gamma radiation in space and in the atmosphere

International Nuclear Information System (INIS)

Lee, M.A.

1986-05-01

A characterization of the gamma-ray fields found in space and in the atmosphere is given. Included are values for the energies and intensities of gamma rays as observed in several experiments and reported in the open literature. Characteristics of the diffuse gamma-ray continuum are presented along with a brief discussion of the sources of this radiation. Also given are discrete gamma-ray line energies and intensities which have been observed in space and in the atmosphere. 37 refs., 7 figs., 12 tabs

Synergistic interaction between the neutron and gamma radiation on LACA mice hemopoietic stem cells

Energy Technology Data Exchange (ETDEWEB)

Xu, H

1982-02-01

Based on the radiation action dual theory of DNA single and double strand breaks, a hypothetical RBE mathematical model for the effect of the mixed radiation of neutron and gamma rays on LACA mice hemopoietic stem cells was formulated. In comparison of the RBE values of different ratio of neutron and gamma-ray mixed radiation with their theoretical additive RBE values, the preliminary impression is that the mixed radiation is more effective than that of the theoretical additive effect. It seems that the existence of synergist in the mixed radiation might be valid.

The effect of gamma radiation on the properties of activated carbon cloth

Directory of Open Access Journals (Sweden)

DANIJELA R. SEKULIĆ

2009-09-01

Full Text Available Activated carbon cloth dressing is an appropriate wound healing material due to its biocompatibility and adsorption characteristics. The in-fluence of gamma radiation as a sterilization process on the adsorption and mechanical properties of activated carbon cloth was investigated. The specific surface area, micropore volume, pore size distribution, surface chemistry as well as the breaking load of activated carbon cloth before and after gamma radiation were examined. Characterization by nitrogen adsorption showed that the activated carbon cloth was a microporous material with a high specific surface area and micropores smaller than 1 nm. Gamma radiation decreased the specific surface area and micropore volume but increased the pore width. The sterilization process changed the surface chemistry quantitatively, but not qualitatively. In addition, the breaking load decreased but without any influence considering the further application of this material.

Scatter radiation intensities around a clinical digital breast tomosynthesis unit and the impact on radiation shielding considerations

Energy Technology Data Exchange (ETDEWEB)

Yang, Kai, E-mail: kyang11@mgh.harvard.edu; Li, Xinhua; Liu, Bob [Division of Diagnostic Imaging Physics, Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts 02114 (United States)

2016-03-15

Purpose: To measure the scattered radiation intensity around a clinical digital breast tomosynthesis (DBT) unit and to provide updated data for radiation shielding design for DBT systems with tungsten-anode x-ray tubes. Methods: The continuous distribution of scattered x-rays from a clinical DBT system (Hologic Selenia Dimensions) was measured within an angular range of 0°–180° using a linear-array x-ray detector (X-Scan 0.8f3-512, Detection Technology, Inc., Finland), which was calibrated for the x-ray spectrum range of the DBT unit. The effects of x-ray field size, phantom size, and x-ray kVp/filter combination were investigated. Following a previously developed methodology by Simpkin, scatter fraction was determined for the DBT system as a function of angle around the phantom center. Detailed calculations of the scatter intensity from a DBT system were demonstrated using the measured scatter fraction data. Results: For the 30 and 35 kVp acquisition, the scatter-to-primary-ratio and scatter fraction data closely matched with data previously measured by Simpkin. However, the measured data from this study demonstrated the nonisotropic distribution of the scattered radiation around a DBT system, with two strong peaks around 25° and 160°. The majority scatter radiation (>70%) originated from the imaging detector assembly, instead of the phantom. With a workload from a previous survey performed at MGH, the scatter air kerma at 1 m from the phantom center for wall/door is 1.76 × 10{sup −2} mGy patient{sup −1}, for floor is 1.64 × 10{sup −1} mGy patient{sup −1}, and for ceiling is 3.66 × 10{sup −2} mGy patient{sup −1}. Conclusions: Comparing to previously measured data for mammographic systems, the scatter air kerma from Holgoic DBT is at least two times higher. The main reasons include the harder primary beam with higher workload (measured with total mAs/week), added tomosynthesis acquisition, and strong small angle forward scattering. Due to the

Improvement of gamma-ray Sn transport calculations including coherent and incoherent scatterings and secondary sources of bremsstrahlung and fluorescence: Determination of gamma-ray buildup factors

International Nuclear Information System (INIS)

Kitsos, S.; Diop, C.M.; Assad, A.; Nimal, J.C.; Ridoux, P.

1996-01-01

Improvements of gamma-ray transport calculations in S n codes aim at taking into account the bound-electron effect of Compton scattering (incoherent), coherent scattering (Rayleigh), and secondary sources of bremsstrahlung and fluorescence. A computation scheme was developed to take into account these phenomena by modifying the angular and energy transfer matrices, and no modification in the transport code has been made. The incoherent and coherent scatterings as well as the fluorescence sources can be strictly treated by the transfer matrix change. For bremsstrahlung sources, this is possible if one can neglect the charged particles path as they pass through the matter (electrons and positrons) and is applicable for the energy range of interest for us (below 10 MeV). These improvements have been reported on the kernel attenuation codes by the calculation of new buildup factors. The gamma-ray buildup factors have been carried out for 25 natural elements up to 30 mean free paths in the energy range between 15 keV and 10 MeV

Effect of Gamma Radiation and Microwave Cooking on Aeromonas Hydrophila in Bolti Fish Fillet

International Nuclear Information System (INIS)

Mohamad, W.S.; Megahed, A.A.; El-Ghaiaty, H.A.; Hafez, T.A.

2016-01-01

The objective of this study is to determine the bactericidal effect of gamma and microwave radiation on Aeromonas hydrophila inoculated in fish fillets. The study revealed that treatment of fish fillets with a dose of 1 kGy gamma radiation reduced the population of A.hydrophila by 104 cfu/g, while the dose of 2 and 3 kGy completely eliminated the microorganism. Treatment of fish fillets with microwave cooking for 1 and 2 minutes completely eliminated the microorganism. The physical examination of fish after gamma radiation treatment revealed that the used doses had no significant changes on fish fillets. The changes in protein profile (amino acids %) depended on radiation dose and period of cooking in microwave alongside controls while the total protein content was not affected.

Discrete level schemes and their gamma radiation branching ratios (CENPL-DLS). Pt. 1

International Nuclear Information System (INIS)

Su Zongdi; Zhang Limin; Zhou Chunmei; Sun Zhengjun

1994-01-01

The DLS data file, which is a sub-library (version 1) of Chinese Evaluated Nuclear Parameter Library (CENPL), consists of data and information of discrete levels and gamma radiations. The data and information of this data file are translated from the Evaluated Nuclear Structure Data File (ENSDF). The transforming code from ENSDF to DLS was written. In the DLS data file, there are the data on discrete levels with determinate energy and their gamma radiations. At present, this file contains the data of 79456 levels and 100411 gammas for 1908 nuclides

Environmental gamma radiation measurements in Bangladeshi houses

International Nuclear Information System (INIS)

Idrish Miah, M.

2002-01-01

The indoor gamma dose rate in air measured using TLDs in the Dhaka district is not wide ranging and follows a normal distribution with an arithmetic mean of 1.54±0.26 mGy.y -1 . The result has been compared with those found by other investigators for different locations of the world. Measurements were made on a monthly basis for a year period, and a sinusoidal variation of monthly indoor gamma radiation of the type: d = 160 + 65 cos p/6 (m -1 ), where d is the indoor dose rate (nGy.h -1 ) and m the month, was observed. This might be due to seasonally varied air exchange rates of the houses. The average annual effective dose and the collective dose equivalent for the residents were estimated to be 0.86 mSv and 172.20 man-Sv respectively based on the indoor gamma exposure. (author)

Environmental gamma radiation measurements in Bangladeshi houses

International Nuclear Information System (INIS)

Miah, M.I.

2004-01-01

Indoor gamma dose rate in air measured using TLDs in the Dhaka district is not wide ranging and follows a normal distribution with an arithmetic mean of 1.54±0.26 mGy y -1 . The result has been compared with those found by other investigators for different locations of the world. Measurements were made on a monthly basis for a year period, and a sinusoidal variation of monthly indoor gamma radiation of the type: d=160+65 cos π/6 (m-1), where d is the indoor dose rate (nGy h -1 ) and m the month. This might be due to the seasonally varied air exchange rates of the houses. The average annual effective dose and the collective dose equivalent for the residents were estimated to be 0.86 mSv and 172.20 man-Sv, respectively, based on the indoor gamma exposure

Environmental gamma radiation measurements in Bangladeshi houses

Energy Technology Data Exchange (ETDEWEB)

Miah, M.I. E-mail: idrish_physics@yahoo.com

2004-06-01

Indoor gamma dose rate in air measured using TLDs in the Dhaka district is not wide ranging and follows a normal distribution with an arithmetic mean of 1.54{+-}0.26 mGy y{sup -1}. The result has been compared with those found by other investigators for different locations of the world. Measurements were made on a monthly basis for a year period, and a sinusoidal variation of monthly indoor gamma radiation of the type: d=160+65 cos {pi}/6 (m-1), where d is the indoor dose rate (nGy h{sup -1}) and m the month. This might be due to the seasonally varied air exchange rates of the houses. The average annual effective dose and the collective dose equivalent for the residents were estimated to be 0.86 mSv and 172.20 man-Sv, respectively, based on the indoor gamma exposure.

Effects of gamma radiations on certain tissues of heteropneustes fossils bloch

International Nuclear Information System (INIS)

Purohit, R.K.; Rathore, N.; Ahluwalia, P.; Srivastava, M.; Gupta, M.L.

1992-01-01

In the present investigation effect of gamma radiation on certain tissues (kidney, stomach and gills) of Heteropneustes fossilis Bloch, an Indian Cat fish, were studied. The fish were irradiated with 10 Gy of gamma radiations at the dose rate of 1.60 Gy/minute from a 60 Co source. Five fish were autopsied at each post-irradiation time of 1,2,3,7,15 and 30 days. Radiation induced histopathology was observed in all the tissues studied. The radio lesions appeared on day-1 after exposure which became exaggerated on day-2 and 3. Signs of recovery were noticed on day-7 which progressed on day-15 and normal histology was observed on day-30. (author). 18 refs

The development of gamma energy identify algorithm for compact radiation sensors using stepwise refinement technique

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hyun Jun [Div. of Radiation Regulation, Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Ye Won; Kim, Hyun Duk; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Yi, Yun [Dept. of of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)

2017-06-15

A gamma energy identifying algorithm using spectral decomposition combined with smoothing method was suggested to confirm the existence of the artificial radio isotopes. The algorithm is composed by original pattern recognition method and smoothing method to enhance the performance to identify gamma energy of radiation sensors that have low energy resolution. The gamma energy identifying algorithm for the compact radiation sensor is a three-step of refinement process. Firstly, the magnitude set is calculated by the original spectral decomposition. Secondly, the magnitude of modeling error in the magnitude set is reduced by the smoothing method. Thirdly, the expected gamma energy is finally decided based on the enhanced magnitude set as a result of the spectral decomposition with the smoothing method. The algorithm was optimized for the designed radiation sensor composed of a CsI (Tl) scintillator and a silicon pin diode. The two performance parameters used to estimate the algorithm are the accuracy of expected gamma energy and the number of repeated calculations. The original gamma energy was accurately identified with the single energy of gamma radiation by adapting this modeling error reduction method. Also the average error decreased by half with the multi energies of gamma radiation in comparison to the original spectral decomposition. In addition, the number of repeated calculations also decreased by half even in low fluence conditions under 104 (/0.09 cm{sup 2} of the scintillator surface). Through the development of this algorithm, we have confirmed the possibility of developing a product that can identify artificial radionuclides nearby using inexpensive radiation sensors that are easy to use by the public. Therefore, it can contribute to reduce the anxiety of the public exposure by determining the presence of artificial radionuclides in the vicinity.

Influence of gamma-radiation on the nutritional and functional qualities of lotus seed flour.

Science.gov (United States)

Bhat, Rajeev; Sridhar, Kandikere Ramaiah; Karim, Alias A; Young, Chiu C; Arun, Ananthapadmanabha B

2009-10-28

In the present study, we investigated the physicochemical and functional properties of lotus seed flour exposed to low and high doses of gamma-radiation (0-30 kGy; the dose recommended for quarantine and hygienic purposes). The results indicated raw seed flour to be rich in nutrients with minimal quantities of antinutritional factors. Irradiation resulted in a dose-dependent increase in some of the proximal constituents. The raw and gamma-irradiated seeds meet the Food and Agricultural Organization-World Health Organization recommended pattern of essential amino acids. Some of the antinutritional factors (phytic acid, total phenolics, and tannins) were lowered with gamma-irradiation, while the seed flours were devoid of lectins, L-3,4-dihydroxyphenylalanine, and polonium-210. The functional properties of the seed flour were significantly improved with gamma-radiation. gamma-radiation selectively preserved or improved the desired nutritional and functional traits of lotus seeds, thus ensuring a safe production of appropriate nutraceutically valued products.

SENSITIVITY OF THE CUMIN SEEDS ASSOCIATED FUNGI TO GAMMA RADIATION

International Nuclear Information System (INIS)

BOTROS, H.W.; HELAL, I.M.; EL TOBGY, K.M.K.

2008-01-01

The present study was carried out to investigate the sensitivity of fungi associated to cumin seeds for gamma radiation. In this regard, the isolated seed associated fungi from the cumin seeds were fifteen fungal species belonging to five genera. The fungal species concerning, Aspergillus ochraceus, Fusarium oxysporium and Aspergillus flavus were the predominant fungi in percentages of 17.8, 15.83 and 12.78 %, respectively. Aspergillus ochraceus was the most effective prevalent fungi on the seed germination causing highest percentage of seed invasion followed by Fusarium oxysporium and Aspergillus flavus. The amylolytic, proteolytic and lipolytic activity and mycotoxin production of the three predominant fungi were negatively influenced by gamma radiation when exposed to doses of 1.0 , 1.5 , 2.5 , 3.5 , 5.0 and 7.5 kGy a behaviour which was parallel to the inhibition in the amount of growth by gamma irradiation

Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation

International Nuclear Information System (INIS)

Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

1987-01-01

Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y

A high-energy, high-flux source of gamma-rays from all-optical non-linear Thomson scattering

Energy Technology Data Exchange (ETDEWEB)

Corvan, D.J., E-mail: dcorvan01@qub.ac.uk; Zepf, M.; Sarri, G.

2016-09-01

γ-Ray sources are among the most fundamental experimental tools currently available to modern physics. As well as the obvious benefits to fundamental research, an ultra-bright source of γ-rays could form the foundation of scanning of shipping containers for special nuclear materials and provide the bases for new types of cancer therapy. However, for these applications to prove viable, γ-ray sources must become compact and relatively cheap to manufacture. In recent years, advances in laser technology have formed the cornerstone of optical sources of high energy electrons which already have been used to generate synchrotron radiation on a compact scale. Exploiting the scattering induced by a second laser, one can further enhance the energy and number of photons produced provided the problems of synchronisation and compact γ-ray detection are solved. Here, we report on the work that has been done in developing an all-optical and hence, compact non-linear Thomson scattering source, including the new methods of synchronisation and compact γ-ray detection. We present evidence of the generation of multi-MeV (maximum 16–18 MeV) and ultra-high brilliance (exceeding 10{sup 20} photons s{sup −1}mm{sup −2}mrad{sup −2} 0.1% BW at 15 MeV) γ-ray beams. These characteristics are appealing for the paramount practical applications mentioned above. - Highlights: • How synchrotron radiation can be produced in an all optical setting using laser-plasmas. • Generating high-energy, high-flux gamma ray beams. • Presenting results from a recent NLTS experimental campaign. • Reveal insight into the experimental techniques employed.

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

International Nuclear Information System (INIS)

Liu Suping; Wu Huailong; Gu Dangchang; Gong Jian; Hao Fanhua; Hu Guangchun

2002-01-01

Radiation fingerprints sometimes can be used to label and identify the radiation resources. For instance, in a future nuclear reduction treaty that requires verification of irreversible dismantling of reduced nuclear warheads, the radiation fingerprints of nuclear warheads are expected to play a key role in labelling and identifying the reduced warheads. It would promote the development of nuclear warheads deep-cuts verification technologies if authors start right now some investigations on the issues related to the radiation fingerprints. The author dedicated to the investigation of gamma-ray fingerprint identifying mechanism for the types of radiation resources. The purpose of the identifying mechanism investigation is to find a credible way to tell whether any two gamma-ray spectral fingerprints that are under comparison are radiated from the same resource. The authors created the spectrum pattern comparison (SPC) to study the comparability of the two radiation fingerprints. Guided by the principle of SPC, the authors programmed a software dedicated to identify the types of radiation resources. The efficiency of the software was tested by a series of experiments with some laboratory gamma-ray resources. The experiments were designed to look into the relations between comparability and radioactive statistics, and the relations between comparability and some measurement conditions such as real time, resource activity and background etc. Two main results can be drawn from the investigation: 1) it is quite feasible to use the concept of spectral comparability to answer the question whether any two gamma-ray fingerprints are identity or not; 2) the identifying mechanism can only identify the types of radiation resources, and cannot identify the individuals with the same type and small differences

A national-wide survey of radon and gamma radiation levels in Australian homes

International Nuclear Information System (INIS)

Langaroo, M.K.; Wise, K.N.; Duggleby, J.K.; Kotler, L.H.