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Determination of absorbed dose in a patient irradiated by beams of x or gamma rays in radiotherapy procedures

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The structural variations of amorphous metals, such as Pd/sub 80/Si/sub 20/, with irradiation of helium ion, neutron, and gamma ray have been mainly pursued by the method of X-ray diffraction and thermal analysis. It should be noticed that the amorphous metals show a radiation resistance, that is, no remarkable structural changes under helium ion, neutron, and gamma ray irradiation.

International Nuclear Information System (INIS)

Pearls change their color to grey by #gamma#-ray irradiation. Grey densities were determined from darkness of pearl nuclei and thickness of the pearl layers. The densities are independent of both diameters of nuclei and pearls. The fading rate increases with increasing storage temperature. The rate of fading for irradiated pearls is lower than that for natural blue pearls. Comparison of photomicrographs (x 12) for pearls irradiated and then stored at room temperature for about 6 years revealed that their surfaces are not substantially different from the surfaces of unirradiated cultured pearls, indicating that #gamma# irradiation hardly gives rise to deterioration. #gamma#-Ray irradiation is a technique for coloration of pearls. Irradiated blue pearls seem to have resistivity to fading and to ...

Science.gov (United States)

The availability of rice, gamma -irradiated up to 4.6 x 10/sup 4/ and 3.5 x 10/sup 5/r for koji was studied. The enzyme activities of koji of the steamed samples were stronger than the unirradiated rice in amylase and protease. The sensory test on the once-steamed irradiated rice was almost the same as the twice-steamed unirradiated rice. (OID)

Science.gov (United States)

Dislocation priming measurements were performed in the kHz range in ASARCO copper. The samples and irradiation facilities are constructed so as to allow successive irradiation of samples both with electrons and gamma rays. The gamma rays were produced by stopping 2.8-MeV electrons in a gold target. The change of the type of irradiation could be achieved without any handling of the sample. Thus it is possible to detect rather small differences between the two types of irradiation. Recovery experiments at 400 deg K after 75 deg K irradiation and pinning rates during irradiation at 400 deg K and 75 deg K were made. (GE)

International Nuclear Information System (INIS)

Ferrite of system, namely Ni_1_-_xZn_xFe_2O_4 with x = (0.0, 0.2, 0.4, 0.6, 0.8, 1.0), have been prepared by solid state reaction to investigate the effect of gamma rays irradiations using Co"6"0 source on the cation distribution, structural and magnetic properties. The unirradiated and irradiated samples were then subjected to characterization techniques such as X-ray diffraction, magnetization and AC susceptibility. The results of these characterizations are found to be different for irradiated from that of the pristine sample. The modifications in respect of irradiated samples are explained in terms of the ion-induced disorder. The important result of #gamma#-irradiation on the cation distribution, structural and magnetic properties is the change of ratio Fe"2"+/Fe"3"+. Possible reasons on the results are proposed.

International Nuclear Information System (INIS)

Recently, foods are often exposed to radiation under packed states with various wrapping materials. In this study, the effects of #gamma#-ray radiation were investigated on the additives in wrapping materials on the market. 10 - 50 kGy #gamma# radiation was irradiated to samples under sealed condition in a glass-ware. Polyethylene bag and wrapping film, polypropylene wrapping film, cup and sheet, and polystyrene cup were used as samples. And the additives in these materials were analyzed by GC/MS to evaluate the radiation effects on them. The irradiation was found to induce rapid degradation of antioxidants, especially, Irgafos 168. Some fatty acid amides used as a lubricant and a plasticizer, DBP were also reduced, but not aliphatic hydrocarbons. However, all polystyrene products used in this study included no additives. The contents of styrene dimer and trimer in those wrapping materials were not ...

International Nuclear Information System (INIS)

Lupinus albus L. plants were grown from seeds and irradiated at various stages of development with acute or chronic gamma rays. All plants were greenhouse grown (pre- and post-irradiation) and allowed to proceed through their normal growth cycle. The purpose of these experiments was to establish a Plactochron Index for Lupinus albus L. and to determine the effects of acute and chronic irradiation on development at the macro and microscopic levels. A Plastochron Index was calculated and used as an indirect time scale to evaluate the effects of gamma rays from a common base line. Acute radiation treatment lasted for a period of a few days, whereas chronic treatment was initiated at the seedling stage and lasted for the entire growth season. Vegetative plants were used to study the effects of acute radiation exposure on apical meristem ...

International Nuclear Information System (INIS)

We report on measurements of radiation hardness of the plastic scintillating fiber SCSF-81. Fibers were irradiated with "6"0Co #gamma#-rays and fast neutrons up to 105 Gy and up to 5 x 1013 n/cm"2, respectively. Deterioration of the attenuation length of the scintillating fiber was studied. Some significant deterioration was observed at the integrated dose of about 1 x 103 Gy and at the integrated neutron flux (neutron fluence) of about 1 x 1012 n/cm"2 for #gamma#-ray and neutron irradiation, respectively. (author).

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The detection efficiency of gamma scanning system in irradiated materials examination facility has been measured. Gamma-ray sources used in this experiment are Cs-Co standard sources a PWR spent fuel rod in which {sup 134}Cs and {sup 154}Eu peaks are clearly identified in the energy region of 500 to 1,600 keV. The distance between source and detector is about 1.6 m. A slit type collimator with 3 mm-width window and 30 mm-thick lead block are installed between source and detector. The detector is a HPGe detector. This equipment is mainly used in gamma scanning of irradiated nuclear fuel. The measured detection efficiency seems to be 1.89 x 10{sup -6} % for 1 MeV gamma-ray. With these results the activities of unknown sources could be measured. This results are expected to be used in the measurement of the absolute distribution of gamma ...

British Library Electronic Table of Contents (United Kingdom)

Polymer insulating materials used in radioactive environments are subjected to a risk of surface degradation caused by tracking. The tracking behavior becomes more complex with the presence of magnetic field. This paper presents investigation of tracking failure of gamma-ray irradiated polybutylene naphthalate (PBN) and polybutylene terephthalate (PBT) under magnetic field. The samples were irradiated in air up to 100 kGy and then up to 1000 kGy with dose rate of 10 kGy/h by using a 60Co gamma-source. Magnetic field Formula Not Shown with flux density of 250 mT was assembled perpendicularly to electric field Formula Not Shown , which gave rise to relative angle between Formula Not Shown and surface normal vector Formula Not Shown of 0degree, 90degree and 180degree, respectively. The experi...

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Neutron and gamma ray energy spectra were measured using an NE-213 scintillator at depths of 7.2, 15.2, and 22.2 cm in a tissue-equivalent phantom which was uniformly irradiated on one face by deuterium--tritium (DT) neutrons. Coupled neutron--gamma ray multigroup discrete-ordinates calculations were performed using semi-infinite slab geometry. These calculations were used to supplement the measured spectra below 1 MeV. Similar calculations were performed to study the perturbation in the phantom due to the detector. The measured and calculated spectra were used to determine the kerma distributions for neutrons and gamma rays at each location. The gamma radiation was determined to contribute more than 10% of the total dose at each depth. The calculated kerma also reveals that a knowledge of the gamma ...

International Nuclear Information System (INIS)

Samples from 314 broiler chickens at 2 months age were analyzed for blood serum level of lysozyme and 311 of them were analyzed also for activity of alternative path-way of complement activity (APCA). Chickens were hatched from eggs, irradiated immediately before incubation with different doses of gamma-rays using Rocus M device - group 1 - control (non irradiated), and groups 2, 3 and 4 - irradiated with doses of 0.15, 0.30 and 0.60 Gy, respectively. Lysozyme concentration was highest for the control group, and for the experimental ones it was lower (p<0.001) which is an indication of the strongly negative effect of gamma-rays on this indicator. For APCA the oppsite relationship was observed - increasing of its activity with increasing of irradiation dose (from p<0.05 to p<0.001) which gave reason to suggest that this phenomenon is due to the ...

KoreaScience (Korea)

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The effect of ionizing radiation (2, 5, and 10 KGy of gamma rays) on muscle ultrastructure of grass shrimps (Penaeus monodon Fabricius) tails at ambient or frozen (-18{sup 0}C) temperature was investigated by transmission electron microscopy (TEM). No significant change was found in muscle ultrastructure of shrimp meat irradiated at doses of 2 or 5 KGy and then stored at 4{sup 0}C for 0 and 8 days. However, in shrimps which were irradiated at ambient temperature at a dose of 10 KGy, the margin of A-band of the myofibrils in longitudinal sections exhibited an irregular zig-zag pattern. In cross section some myosin filaments in the A-band regions were missing. A possible interpretation of these results would be that 10 KGy gamma irradiation dose at ambient temperature depolymerized myosin in the A-band from the tail of thick filament. Actin damage was also ...

International Nuclear Information System (INIS)

The present study was designed to assess the radioprotective effects of amifostine on ovarian follicles. Three week-old female mice with or without pretreatment of amifostine were irradiated with 6.42 Gy of #gamma# -ray. Ovaries were collected 0 and 6h after irradiation. DNA fragmentation pattern and expression of genes and activity of proteins related with apoptosis were investigated by means of RT-PCR and Western blot. Proliferation of granulosa cells was reduced and incidence rate of follicular atresia was increased in ovarian follicles in #gamma# -ray irradiated mice compared to those in control or amifostine-treated group. DNA fragmentation was increased in time-dependent manner in granulosa cells of all irradiated groups. However, no difference between amifostine pre-treated group and ...

British Library Electronic Table of Contents (United Kingdom)

Purpose Study the radiolysis of solid-state metoclopramide hydrochloride at various absorbed doses. Elucidate the structure of the degradation products to gain information on the radiolysis mechanisms. Methods Solid-state metoclopramide samples were irradiated at several doses with gamma rays and high-energy electrons to evaluate the influence of the dose rate. High-performance liquid chromatography with a diode array detector was used to measure the chemical potency as a function of the absorbed dose and to quantify the degradation products. The characterization of degradation products was performed by liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Results The degradation of solid-state metoclopramide after irradiation was negligible. No qualitati...

Energy Technology Data Exchange (ETDEWEB)

A algorithm was developed to determine the characteristic parameters of PWR spent fuel, such as burnup, cooling time and initial enrichment of {sup 235}U by use of gamma-ray activity ratios of {sup 134}Cs/{sup 137}Cs, {sup 154}Eu/{sup 137}Cs and {sup 106}Ru/{sup 137}Cs from the high resolution gamma-ray spectroscopy and ORIGEN-S calculations. For the verification of the method developed, gamma-ray measurements of Kori-1 and Kori-2 nuclear fuel rods were carried out using HPGe gamma ray scanning system. As a results, it is revealed that the measured values are in a good agreement with the operator declared values within the about {+-} 5% errors. Besides, the under-water burnup measuring device has been designed to measure the gamma-ray from the PWR spent fuel assembly. This device will be set up in the pool of Post-Irradiation Examination ...

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The molar of guinea pigs was irradiated with /sup 60/Co-..gamma.. ray for daily observations of the manifestation of disturbed tooth formation by microradiography and the time registration by tetracycline-labelling. Irradiation first injured young blast cells of the dentin in the growth phase, dental pulp cells, and cells of the enamel. The portion composed of injured cells formed a depressed ''constriction'' from the dental pulp side toward the border between the enamel and dentin. The cells of the enamel injured by irradiation in the growth phase later formed a very thin irregular stroma. In contrast, cells in the differentiation or subsequent phase at the time of irradiation and cells probably having started to grow after irradiation proceeded with formation of a normal stroma and calcification. No ...

International Nuclear Information System (INIS)

The inverse Compton scattering between positron bunches and the Free Electron Laser (FEL) of the SuperAco storage ring generates a collimated and tunable gamma-ray beam. The use of the FEL instead of a conventional laser, automatically provides the transverse alignment and synchronisation of the electron and optical beams. The Super-ACO FEL is operated in the 300-430 nm range at 800 MeV with a high repetition rate (8 MHz) and an average transmitted power of 300 mW at 350 nm. High energy gamma rays of 35 MeV are produced with a rate of 1.5 10 7 photons/second and good monocromaticity (about 10%). Applications of the SuperAco FEL installation for diamond irradiation and biological studies are envisaged. (author)

International Nuclear Information System (INIS)

Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by #gamma#-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H_5_0 according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from "4"0K contained in the ...

International Nuclear Information System (INIS)

Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85"0C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to #gamma#-rays. A thin aluminium foil was used to cover the inner wall of the reaction vessel so that the extent of homo polymer could be reduced to be less than 1.6% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmations of graft copolymerization and saponification reactions were made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the same total dose on the extent of grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.

International Nuclear Information System (INIS)

... electrophoresis fission products gamma radiation gamma spectra half-life

International Nuclear Information System (INIS)

Seven types of shellfish were irradiated by gamma ray at doses of 0, 3 and 6 kGy. Pulse photo-stimulated luminescence (PPSL) and thermoluminescence (TL) methods were employed to detect the radiation treatment. The screening of irradiation was carried out by the PPSL method followed by identification using the TL technique. Most of the irradiated shellfish were screened out correctly and only a few showed photon counts a bit higher than the lower threshold value by much lower than the upper threshold value. The TL method was employed using minerals isolated from all the control and irradiated shellfish samples by density gradient treatment. Three parameters, integrated intensities of first glow curves (TL1), ratios of first to that of second glow curves (TL1/TL2), and the shapes of maxima of first glow curves, were utilized for the identification of ...

International Nuclear Information System (INIS)

In future collider experiments, where a background radiation level is estimated to be very high, e.g. around 10"2 #approx# 10"5 Gy/yr and 10"1"1 #approx# 10"1"4 n/cm"2/yr at SSC, the detectors operating around the collision point in the experiments will encounter a considerable amount of radiation. Therefore, the detectors, especially the calorimeter, are required to be resistive against high radiation levels. From this point of view, it is of great importance to study the effects of radiation damage on the performance of the detectors. The authors report preliminary results of measurements of radiation hardness of the plastic scintillating fiber Kuraray SCSF-81 against irradiation with fast neutrons and "6"0Co #gamma#-rays in the region of the neutron fluence from 1 x 10"1"1 to 5 x 10"1"3 n/cm"2 and the integrated #gamma#-ray dose from 890 to 10"5 Gy, respectively. Deterioration of both intrinsic light yield and light ...

CERN Document Server

Polarization measurements in the X-ray and gamma-ray energy range can provide crucial information on massive compact objects such as black holes and neutron stars. The Polarized Gamma-ray Observer (PoGO) is a new balloon-borne instrument designed to measure polarization from astrophysical objects in the 30-100 keV range, under development by an international collaboration with members from United States, Japan, Sweden and France. To examine PoGO's capability, a beam test of a simplified prototype detector array was conducted at the Argonne National Laboratory Advanced Photon Source. The detector array consisted of seven plastic scintillators, and was irradiated by polarized photon beams at 60, 73, and 83 keV. The data showed a clear polarization signal, with a measured modulation factor of $0.42 \\pm 0.01$. This was successfully reproduced at the 10% level by the computer simulation package Geant4 after ...

International Nuclear Information System (INIS)

Radiation damage and its recovery in the light emittance efficiency and the attenuation length of barium fluoride (BaF_2) scintillator have been investigated. The light yield and transmittance of small samples of BaF_2 scintillator were measured after #gamma#-irradiation from 0.5x10"4 to 1.1x10"5 Gy for deterioration, and after sunlight exposure for recovery. Suspension of deterioration was observed both in light yield and in attenuation length at an integrated dose of #gamma#-rays of about 10"4 Gy. Fairly good and quick recovery of the deteriorated BaF_2 scintillator was obtained by sunlight exposure. Using a Monte Carlo simulation method, the dependence of the light emittance efficiency on #gamma#-irradiation and sunlight exposure was studied. It has been found that the light emittance efficiency, as well as the attenuation length, is influenced by #gamma#-irradiation and sunlight exposure. (orig.).

International Nuclear Information System (INIS)

Juvenile trees of kalmia derived from shoot tip culture, and seedlings of kobus were irradiated with #gamma#-rays. In kalmia, two mutation lines were obtained which had narrowlong leaves. In kobus two mutation lines were obtained. One mutation line has flowers with 7 to 13 petals. Another mutation line has yellow-green variegated leaves. (author).

International Nuclear Information System (INIS)

(1) Young chrysanthemums were planted after being irradiated at the time of shoot tip culture and the influence of irradiation was evaluated from the point of view of establishment of mutants. (2) Two cultivars, Kin-tenryu and Tenryu-no-asa were used in this experiment. The percentage of cultivars healthy enough to transplant on June 10, 1972 showed a decrease in proportion to the increase of dosage. Some plants of cultivar Kin-tenryu died after being transplanted. (3) Few plants of either cultivar could overwinter, and in particular no plant irradiated by gamma-rays of 20 kR. (4) Plant height showed a tendency of inhibition in both cultivars. (5) Three chlorophyll mutants showing chimera appeared. One of them was in the cultivar Tenryu-no-asa irradiated by 10 kR at 3 days after planting; two of them were in the cultivar Tenryu-no-asa irradiated by 10 kR at 5 ...

International Nuclear Information System (INIS)

... chemical radiation effects decomposition extraction columns gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Upon irradiation of aqueous ethylene glycol/water solutions of native chloroperoxidase (CPO) with {sup 60}Co-gamma rays at 77K one observes the one-electron reduction of the enzyme active site by radiolytically generated thermolyzed electrons. In the present study the first absorption spectrum of a low-spin ferrous form of CPO is reported which has peaks at 438, 532 and 563 nm, similar to those observed previously for cytochrome P-450. All previously described ferrous forms of CPO are high spin. In order to observe the final results of the CPO reaction with electrons, the spectral changes of native enzyme after room temperature-gamma-irradiation have also been investigated. Evidence of changes is also presented probably connected with disruption of the tertiary structure of enzyme, correlated with decrease of enzyme activity.

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The objective of this work was to combine asymmetric somatic hybridization (donor-recipient fusion or gamma fusion) to microprotoplast-mediated chromosome transfer, as a tool to be used for chromosome mapping in Citrus. Swinglea glutinosa micro protoplasts were irradiated either with 50, 70, 100 or 200 gamma rays and fused to cv. Ruby Red grapefruit or Murcott tangor protoplasts. Cell colonies were successfully formed and AFLP analyses confirmed presence of S. glutinosa in both 'Murcott' tangor and 'Ruby Red' grapefruit genomes. (author)

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This study was carried out to evaluate the biochemical and morphological effects of ionizing radiation on ovary. Immature mice (ICR, 3 week-old) were irradiated at a dose of LD{sub 80(30)} at KAERI. The ovaries were collected after 6 hours, 12 hours, 1 day, and 2 days post irradiation. To analyze the morphological changes, histological staining with hematoxylin-eosin, immuno- histochemical preparation using in situ 3'-end labeling was performed. DNA fragmentation analysis and flowcytometric evaluation of DNA extracted from whole ovary were performed. As a result of DNA fragmentation analysis, DNA fragments with 185, 370, and 555 base pairs were clearly shown at 6 hours post irradiation. The percentage of A{sub 0} cell cycle was significantly increased in the irradiated group than control. In situ 3'-end labeled follicles were increased at 6 hours post irradiation. ...

International Nuclear Information System (INIS)

Carcinogenesis is now generally recognized to be an important detrimental effect in man after low dose irradiation. The carcinogenic action of ionizing radiation is clearly demonstrated after exposure to relatively high doses (in excess of 0.5 Gy) but for lower dose levels reliable direct observations are not available. With the introduction of special protocols for the performance of large scale screening programs by mammography the average absorbed dose in glandular tissue in the average breast can be restricted to a value of 3 mGy per mammogram. The risk for tumor induction after exposure to these low doses can never be established from human epidemiology. In order to investigate the risk of repeated exposure to small dose of ionizing radiation the induction of mammary tumors has been investigated in rats of the WAG/Rij strain after single and fractionated irradiations with gamma-rays. (author). 8 refs., 3 figs.

International Nuclear Information System (INIS)

There are several on-going projects of e"+e"- colliders. If they are constructed, we can convert them into photon-photon (#gamma#-#gamma#) colliders by converting electron beams into #gamma# beams, irradiating laser beams just before the interaction point. In this report we discuss the technical issues on the accelerator.

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To obtain Pinus wood-plastic composites, wood samples were impregnated with methyl methacrylate and polymerized by the use of gamma rays from a /sup 60/Co at different dose exposure and total dose. The best percentage of polymerization was obtained with the exposure of 2.0 MR of gamma radiation. It was found that the impregnation and polymerization, determined by the density values along the samples were uniform. The density became 2.6 times higher in relation to the control samples. The storage of the impregnated wood samples showed losses of the monomer, even when wrapped with aluminum or polyethylene film. It is recommended that the wood samples should be irradiated soon after impregnation.

International Nuclear Information System (INIS)

In the fields of medical imaging, geophysical well logging, and industrial radiography, it is often of interest to characterize the spatially distributed sensitivities of neutron and gamma-ray measurement devices to the physical properties of the materials being examined. For instance, one may wish to know how the count rate in a detector varies in response to small changes in the local density of the irradiated object as a function of position. Experimental determination of such sensitivity functions is often impractical. Consequently, we have developed a general three-dimensional Monte Carlo numerical technique that allows us to directly compute the differential sensitivity of an arbitrary integral response parameter, such as a time- or energy-discriminated count rate, with respect to the spatial distribution of macroscopic cross sections and sources in the irradiated medium. Sensitivities to object density, porosity, ...

International Nuclear Information System (INIS)

This paper reports regulation of hypoxia inducible factor-1 ? (HIF-1 ?)in hepatoma cells by irradiation. Cobalt chloride (CoCl2), a chemical mimic agent for hypoxia research, was utilized to induce the stable expression of HIF-1 ? in HepG2 cells. The HepG2 cells were irradiated to different doses to observe the changes of HIF-1 ?. The level of intracellular reactive oxygen species (ROS) was assayed by fluorescent microscope and flow cytometry (FCM). The results showed that there were obvious changes in expression of HIF-1 ? after HepG2 cells exposed to radiation, and the changes were positively related with the irradiation dose from 1 Gy to 5 Gy. Moreover, contents of incellular ROS were negatively correlated with above levels of HIF-1 ? from 1 Gy to 3 Gy. The results indicate that irradiation may enhance hypoxic cells HIF-1 ?, and the reduction of intracellular ROS can contribute to the regulation of ...

International Nuclear Information System (INIS)

Irradiation of live bivalve molluscs is a promising new technique to reduce the public health threats of viral and bacterial pathogens in the consumption of raw shellfish. In studies conducted within the past year, live hardshelled clams and oysters were innoculated with Simian Rotavirus SA-11, Poliovirus I, and Hepatitis-A virus and treated with gamma ray ionizing radiation from University of Lowell/DOE 800,000 Curie "6"0Co source over a dose range of 0.5--10 kiloGray (50--1000 kilorad) to determine the effectiveness of the process in eliminating viral activity and thus easing the potential viral health threats associated with uncooked bivalves. Two viral strains, SA-11 and Poliovirus I, were employed as models to perfect laboratory technique and to estimate the most appropriate range of dose exposures necessary for optimal inactivation of the infectious pathogen, Hepatitis A. Post-irradiation ...

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Natural rubber latexes were vulcanized by ..gamma..-rays with two polyfunctional monomers, neopentylglycol diacrylate (A-NPG) and dimethacrylate (NPG). In comparison with A-NPG, NPG was more soluble in rubber particles, but it was less effective as an accelerating agent for the vulcanization because of the smaller rate of polymerization. On the other hand, the colloidal stability of the latex containing A-NPG was low because it was localized on the surface of rubber particles due to its poor solubility to the particles. The solubility of A-NPG was improved by adding A-NPG with solvents. The maximum tensile strength of the irradiated latex film was 350 kg/cm/sup 2/ at 3 Mrad.

International Nuclear Information System (INIS)

Carrier-free "8"8Y radioisotope, which has the longest half life (T=106.6 d) of yttrium radioisotopes and is a #gamma#-ray emitter, was obtained by proton irradiation of strontium, followed by cooling for one month. Then, "8"8Y was purified by precipitating strontium as strontium nitrate and extracting yttrium with tri-n-butyl phosphate (TBP). The decontamination factor of strontium to yttrium was more than 4x10"3 and chemically pure yttrium radioisotope was obtained. (author) 6 refs.

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For a new and practical {sup 99m}Tc generator using not (n, f){sup 99}Mo, but (n, {gamma}){sup 99}Mo, an inorganic polymer adsorbent framed with oxygen-zirconium-chlorine bonds with a high adsorption performance of Mo has been developed; the polymer adsorbent was named PZC. The amounts of {sup 99}Mo (Mo) adsorbed are stably more than 250 mg/g(PZC). But, the current experiments with 0.5 MBq to 1.85 GBq of {sup 99}Mo gave a subject that the breakthrough of {sup 99}Mo in the elution of {sup 99m}Tc from the adsorbent was 0.05-0.5 %, although the breakthrough of Zr was less than the detection limit of 5 x 10{sup -2} mg(Zr) to 1 g of PZC, and {sup 99m}Tc was eluted constantly with 78{+-}4%. To apply the adsorbent as a generator commercially in Japan, the {sup 99}Mo breakthroughed from the generator must be suppressed to less than 0.15 kBp({sup 99}Mo)/MBq({sup 99m}Tc) by law which is equivalent to 0.015 %, and the {sup 99}Mo breakthrough is controlled practically to less ...

Science.gov (United States)

A computer-based beam dosimetry measurement system for boron neutron capture therapy provides accurate, sensitive, and rapid readout and recording of all beam dose components, epithermal and thermal neutron flux, and gamma-ray dose rate. This dosimetric system includes input from the characterization of the epithermal neutron beam developed at the Massachusetts Institute of Technology, actual BPA pharmacokinetic data from a specific human subject being irradiated, output of MacNCTPLAN, a treatment planning system developed by the authors group, and input from the five on-line beam detectors. The purpose of this system and associated readout systems is to ensure that the desired dose is delivered to the subject within acceptable dose tolerances, e.g., {+-}5% of the target dose, and that any perturbations in the neutron beam that may occur during irradiation can be rapidly evaluated and the appropriate measures taken.

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An apparatus for non-invasively inspecting an object, such as an item of luggage, for explosives material is described. It comprises a multi-channel thermal neutron inspection system having a plurality of neutron irradiation chambers. Simultaneous operation of several channels increases the maximum system throughput several times. Each chamber has a lithium neutron source which is stimulated to neutron production by a proton beam. Beam switching magnets are energised by pulsing to divert a common proton beam to each source in turn. The initial beam is generated by a radio frequency quadrupole accelerator. The advantages of this system are very low residual source activity and controllable neutron production thereby minimising safety hazards. The irradiation chamber may contain several different gamma ray detectors to identify the elements present in explosives material. In addition, a neutron ...

International Nuclear Information System (INIS)

Soybean is one of the most economical and nutritious food packed with basic nutrients that combat diseases stemming from mal- and under-nutrition. Despite its rich nutritional profile, use of soybean in food has been limited because soybean proteins are often associated with compounds, which could exert a negative impact on the nutritional quality of the protein. Trypsin inhibitor (TI) is one of the important anti-nutritional factors that exert negative effect by causing growth inhibition. Soybean cultivar VLS-2 was irradiated with 250 Gy gamma rays in a gamma cell (200) with 60Co source installed at BARC to induce mutations for low trypsin inhibitor content. Three mutants with lower levels of TI content were identified and can be utilized for developing elite varieties of soybean. (author)

Science.gov (United States)

... Accession Number : AD0268549. Title : POTENTIATION BY PENTOBARBITAL OF THE PROTECTIVE EFFECT OF AET AGAINST GAMMA RAYS. ...

Energy Technology Data Exchange (ETDEWEB)

This patent describes a {gamma}-ray detector. It comprises: a dislocation-free single crystal having an input surface and a transmission surface at opposite ends thereof; an active shield surrounding the crystal and functioning as an anticoincidence counter; and {gamma}-ray detector means disposed adjacent the transmission surface of the crystal for receiving and detecting {gamma}-rays of a predetermined wavelength incident on the input surface of the crystal at a specific Bragg angle and transmitted through the crystal.

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Cell death in general can be a physiological process of cell number regulation in tissue, or it can be the result of exo or endogenous injuries, such a low-dose of radiation. Chicken B cell population in the bursa of Fabricius are very susceptible to PCD. Our present studies concern the development of radiation damage of chicken defence mechanisms. In 6 experiments pathogen free chicken were irradiated by gamma rays with the total doses of 0.25, 0.5, 1.0, 2.0 and 4.0 Gy. The induction of apoptosis was checked by Flow-cyto-meter 12 h after irradiation in bursa cell suspension. There is some increase in the number of induced apoptotic cells 12 h after irradiation at the dose 0.5-.4.0 Gy. There were no significant changes in the proportion of proliferating lymphocytes (G2 M), but cellularity decreased significantly at dose 2.0 and 4.0 Gy/12 h after irradiation. ...

Energy Technology Data Exchange (ETDEWEB)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

Energy Technology Data Exchange (ETDEWEB)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

Energy Technology Data Exchange (ETDEWEB)

Massive particle candidates for dark matter provide a potentially observable signature by virtue of their annihilations in the galactic halo at a known but model-dependent rate. Possible signatures are described, including cosmic ray antiproton and gamma-ray production. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Two neutron emesis experiments were conducted at the Armed Forces Radiobiology Research Institute (AFRRI). In both experiments (described as Phase I and Phase II) the radiation dose required to cause emesis in 50% of subjects (ED50) was determined for both neutron reactor and gamma reactor source radiation. Emesis onset, offset and duration times post-exposure are reported. Neutrons were maximized from the reactor by passing the beam through a 15.25 cm (6 in.) thick lead wall to filter out gamma photons. Gamma rays were maximized by thermalizing neutrons in 30.5 cm (12 in.) of water, then absorbing the thermal neutrons in a gadolinium-cadmium shield. In Phase I, 28 dogs were exposed to radiation: 12 were exposed to gamma photons at the rate of 0.69 Gy/min and 16 were exposed to neutrons at 1.2 Gy/min. In Phase II, 58 dogs in 3 groups were exposed to radiation: 19 were exposed in the ...

Science.gov (United States)

For abstract, see NSA 26 23, number 56263.

International Nuclear Information System (INIS)

Effects of #gamma#-irradiation on synthetic polymers and paper used as packaging materials for irradiated food have been studied by NMR. Polystyrene, polybutadiene and some copolymers were studied before and after the #gamma#-irradiation treatment and in the presence or absence of antioxidants and stabilisers. In the absence of additives, the effect of #gamma#-irradiation on polystyrene is negligible even irradiating at high doses. In turn, the role of antioxidants and stabilisers is crucial in polybutadiene and butadiene-containing copolymers. Wood pulp paper was also studied by NMR. Preliminary measurements on #gamma#-irradiated wood pulp sheets show a shortening in the T_2 relaxation time component due to the bound water, i.e. some of the bound water is lost. (author)

Energy Technology Data Exchange (ETDEWEB)

Effects of gamma irradiation on hygienic quality and extraction yields in twenty-one kinds of Korean medicinal herbs were investigated. Gamma irradiation at 5-10 kGy inactivated contaminating microorganisms. The total extraction yield in fifteen kinds of the investigated medicinal herbs increased by 5-25% by a dose of 10 kGy. (author)

International Nuclear Information System (INIS)

In this experiment, we measured the detection efficiency of gamma-scanning system of Irradiated Materials Examination Facility (IMEF) in Korea Atomic Energy Research Institute(KAERI) for the spent PWR fuel and activity known sources with high activity. We measured the absolute detection efficiency of gamma scanning system of IMEF to the "1"3"7Cs-source with 10.4 GBq and "6"0Co source with 25.9 GBq High-activity sources as standard sources, and a fuel burned in the KORI -1 reactor of the Kori Nuclear power plant. In analyzing, we used three peeks those were the 661.64 keV peak form "1"3"7 Cs 1173.23 and 1332.51 keV"6"0 Co sources, and 14 peaks of "1"3"4Cs and "1"5"4Eu on the spent fuel gamma spectrum which are in the energy range from 500 to 1,600 keV. We find second order equations for detection efficiency by using our experimental results. The equation show that the detection efficiency of ...

Energy Technology Data Exchange (ETDEWEB)

AGROSTER Co irradiates food packaging material and some types of spices for the meat industry. The step by step strategy of AGROSTER has been very successful. In the last year, its gamma facility was used as much as possible to irradiate food items. The government of Hungary has recognized the benefit of this technology and has given financial assistance to establish a large commercial gamma irradiator in Budapest.

Energy Technology Data Exchange (ETDEWEB)

This report compares the performance characteristics of /sup 10/B-lined and fission-neutron detectors in gamma-ray fluxes typical of the fields to be encountered during nondestructive testing of irradiated light-water fuel assemblies stored in water. Using the optimum time constants for each of the /sup 10/B-lined detectors, the 0.25-in.-dia detector had a 5% loss in neutron count sensitivity at 7000 rad/h. Similarly, the 0.5-in.-dia detector had a 7% loss at 13,000 rad/h and the 1-in.-dia detector had a 5% loss in sensitivity at 1000 rad/h. Uranium-235 fission chambers were operated successfully in fields above 100,000 rad/h with no loss in neutron counting sensitivity. Shielding calculations were done to determine the appropriate shield thickness needed for a /sup 10/B-lined neutron detector to operate in a 50,000 rad/h field, typical of light-water-reactor spent-fuel assemblies stored in water. 7 refs., 4 figs., 9 tabs.

Energy Technology Data Exchange (ETDEWEB)

The rates of hydrogen release from simulated high-level liquid waste (SHLLW) during irradiation of {sup 60}Co {gamma}-rays have been studied using a laboratory-scale apparatus. The SHLLW used was made up of 28 different metal elements, the concentrations of which were determined from a computed data (ORIGEN-2) for a Purex spent fuel (burn-up of 4.5 GWd/t, cooling time of 4 years) except for those of corrosion products (Fe, Cr and Ni) and of chemical process additive (P). The nitrate ion concentration of the SHLLW was 4.97 M. The G-value of hydrogen release was 0.0164 for stirred conditions, but for nonstirred conditions with dose rate : 2.8 kGy/h and with the SHLLW solution height more than 8 cm, the following relation was found between the G-value and the solution height (d cm); G(H{sub 2}) = 0.100 d{sup -1.6}. The G-values of oxygen and nitrogen releases were also determined. (author)

International Nuclear Information System (INIS)

A brief description of the physical process of dose enhancement effects produced by X-ray radiation on materials is given, with emphasis on the influence on electronic devices. The damages caused by X-ray radiation dose enhancement is more serious than that of #gamma#-ray with higher energy.

Energy Technology Data Exchange (ETDEWEB)

This project has intended to develop alternative techniques to be used in food industry for food processing and utilization by safe irradiation methods. For improvement of rheology and processing in corn starch by irradiation, the production of modified starch with low viscosity as well as with excellent viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added inorganic peroxides to starch. Also, this project was developed the improvement methods of hygienic quality and long-term storage of dried red pepper by gamma irradiation. And, in Korean medicinal plants, 10 kGy gamma irradiation was effective for improving sanitary quality and increasing extraction yield of major components. For the sanitization of health and convenience foods, gamma ...

Energy Technology Data Exchange (ETDEWEB)

The X-ray properties of the main sequence Be stars conclude that they are a widely separated binary system containing an accreting neutron star.

International Nuclear Information System (INIS)

Full text: A Large Sample Neutron Activation Analysis (LSNAA) facility is under development at GRR-1 research reactor, NCSR 'Demokritos'. The LSNAA facility design incorporates sample irradiation in the reactor's graphite thermal neutron column and subsequent measurement of the activity induced at a gamma spectroscopy system with gamma ray transmission measurement options included. Monte Carlo neutron and photon transport code MCNP-4C was used to model the facility. Appropriate correction factors accounting for neutron field perturbation during sample irradiation, high purity germanium detector efficiency for the volume source and gamma ray self-absorption within the sample itself were derived. The results of the computations were experimentally verified by activation foil measurements for a set of known materials and a range of sample sizes ...

International Nuclear Information System (INIS)

Metabolic profile is an important biological marker of neoplastic processes not only in the tumor itself but also in the host organism. The neuro-hormone melatonin has been implicated in the experiments as an oncostatic agent. Female Wistar:Han SPF rats (Velaz, Prague, Czech Republic) were irradiated continuously for 15 days using a daily gamma rays dose of 96 mGy. At the end of exposure one group of rats was administered 5 mg/kg b.w. of dimethylbenz/a/anthracene (DMBA) intragastrically. During the period of exposure to ionizing radiation a part of the animals was supplied with melatonin (M) at a concentration of 20 #mu#l/ml in drinking water. Selected parameters of lipid and carbohydrate metabolism and levels of selected hormones were determined 2, 30 and 100 days post-irradiation. The irradiation itself caused only small changes in tissue lipids. The application of a single low ...

International Nuclear Information System (INIS)

The effects of the antioxidants, vitamin E, propyl gallate, 2-t-butyl-4-methoxy phenol (BHA), 2,6-di-t-butyl-4-methoxy phenol (BHT), nor-dihydroguaiaretic acid (NDGA) and diphenyl-p-phenylene diamine (DPPD) in concentrations ranging between 0.001 per cent and 0.1 per cent have been tested on lipid peroxide formation in synthetic diet mixtures containing herring oil (10 per cent) mixed with starch (90 per cent) irradiated with #gamma#-ray doses of 100 to 2000 krad. On a weight basis NDGA, DPPD, BHA and BHT were most effective and vitamin E and propyl gallate were least effective. An antioxidant concentration of 0.01 per cent normally protected against peroxide formation after a dose of 500 krad but if the dose was increased to 1000 or 2000 krad, much higher doses of antioxidant, up to 0.1 per cent, were required to give protection. Antioxidants prevented peroxide developing during post-irradiation storage even when added ...

Energy Technology Data Exchange (ETDEWEB)

To study CdZnTe as a high energy resolution gamma ray detector with a novel new design, and to build a detector array from the new detector design

Energy Technology Data Exchange (ETDEWEB)

We summarize some initial results in our investigation of the nuclear physics issues of gamma-ray lasers. We describe what is known thus far from existing experimental data and illustrate how theoretical models may be employed for systematic searches of candidate nuclei.

International Nuclear Information System (INIS)

The synthetic process of polyethylene cation exchange capillary via radiation grafting polystyrene by simultaneous irradiation with "6"0Co #gamma#-ray source and sulfonation with concentrated H_2SO_4 was studied. The effects of dose, dose rate, monomer concentration, solvents, temperature and crosslinking agents on the graft copolymerization of styrene with polyethylene capillary were illustrated. The relationship between the radiation grafting conditions and the properties of ion-exchange capillary were examined. A polyethylene cation exchange capillary with I.D. 0.8 mm, length 20 m, exchange capacity 0.7 Meq/g 60% capacity in 10 s (flow rate 20 ml/min) was prepared. No significant loss of copacity was found from this ion-exchange capillary after 200 adsorption/regeneration cycles.

International Nuclear Information System (INIS)

The first part of the study contains a literature compilation of more than 50 original publications reporting the radiation induced effects in 17 different high polymer materials and glass which are relevant in the manufacturing of medical devices or packing materials. The results collected demonstrate that high energy radiation, i.e. gamma- or X-rays, causes various physical and chemical alterations in high polymer materials. A detailed summary and discussion of the results of the original publications is not included in the present report, it will be presented in the second part of the study. Furthermore, the second part of the study will refer to the aspect of wholesomeness of irradiated medical devices or packing materials in a more general manner of representation. (orig.).

International Nuclear Information System (INIS)

The excitation functions of the reactions "9"8Mo(d,p)"9"9Mo and "1"0"0Mo(d,p)"1"0"1Mo have been determined by irradiation of stacked foils with deuterons of energies less than 13 MeV and non-destructive determination of the absolute activity of the Mo radioisotopes by semiconductor #gamma#-ray spectrometry. From the excitation functions, the thick-target yields and the saturation production rates of "9"9Mo and "1"0"1Mo for deuteron energies of 13.0 MeV and 11.7 MeV have been calculated. Implications for the production of "9"9Mo for generators of sup(99m)Tc are discussed. (author).

Energy Technology Data Exchange (ETDEWEB)

Specific parts of several plants (fruits, leaves, stem, bark and roots) often used as medicines in the Indian Ayurvedic system have been analysed for 20 elements (As, Ba, Br, Ca, Cl, Co, Cr, Cu, Fe, K, Mn, Mo, Na, P, Rb, Sb, Sc, Se, Sr and Zn) by employing instrumental neutron activation analysis (INAA). The samples were irradiated with thermal neutrons in a nuclear reactor and the induced activity was counted using high resolution gamma ray spectrometry. Most of the medicinal herbs have been found to be rich in one or more of the elements under study. (Author).

Science.gov (United States)

Black holes have been predicted since the 1940's from solutions of Einstein's general relativity

International Nuclear Information System (INIS)

Presented are the investigation results of electrophysical and physico-mechanical properties of KLF-20, Viksint U-4-21, Viksint KT-73, UF-7-21, KG-184, KL-4, KL-16SE-305, VIAT-1 and PPK-21 sealants, irradiated with sources of continuous and pulse #gamma#-radiation, as well as pulse #gamma#-neutron radiation. It is shown that electrophysical and physico-mechanical properties of sealants after irradiation by continuous #gamma#-radiation up to 10"6 doses and pulse gamma-neutron radiation with neutron fluence of 10"1"3 neutron/cm"2 and #gamma#-radiation dose of 10"4R do not practically change. Electric conductivity and tangent of the angle of dielectric losses increase in the process of irradiation. Electric conductivity depends on irradiation type, is proportional to dose rate and does not depend on ...

Energy Technology Data Exchange (ETDEWEB)

Wood/polymer composites (WPC) have been prepared from pinewood with different compounds using gamma irradiation: butyl acrylate, butyl methacrylate, styrene, acrylamide, acrylonitrile, and unsaturated polyester styrene resin. The polymer loading was determined with respect to the compound concentration and the irradiation dose. The polymer loading increases generally with increase in the monomer or polymer concentration. Tensile and compression strength have been improved in the four cases, but no improvement was observed using unsaturated polyester styrene resin or acrylamide.

CERN Document Server

Based on BACODINE network notification the Whipple Observatory gamma-ray telescope has been used to search for the delayed TeV counterpart to BATSE-detected gamma-ray bursts. In the fast slew mode, any point in the sky can be reached within two minutes of the burst notification. The search strategy, necessary because of the uncertainty in burst position and limited FOV of the camera, is described.

Energy Technology Data Exchange (ETDEWEB)

Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model ...

International Nuclear Information System (INIS)

Calculations have been made to determine the production of "1"8"8W from "1"8"6W in several US fission reactor systems, e.g., Fast Flux Test Facility (FFTF), the High Flux Isotope Reactor (HFIR), and the Advanced Test Reactor (ATR). Important input to these calculations are the cross-section parameters for "1"8"6W, "1"8"7W, and "1"8"8W. Only two values have been measured for "1"8"7W and none for "1"8"8W. Consequently, results from integral measurements play a crucial role in determining the "1"8"7W and "1"8"8W values. This has been studied for irradiations in the FFTF and the Oregon State Univ. (OSU) research reactor. Short irradiation of enriched "1"8"6W in both the FFTF and the OSU reactors have produced #mu#Ci/g quantities of "1"8"8W/"1"8"8Re. Measurements were made of the "1"8"8W gamma ray emission. These results were incorporated with other available data to provide more accurate "1"8"8W ...

International Nuclear Information System (INIS)

For ages, herbs have been used as medicine and food. Nowadays, the interest in phytotherapeutics is increasing as well as the consumer attention. Some biochemical compounds synthesized by plants as alkaloids, phenolics, flavonoids, essential oils, tannins and vitamins, influence the composition of these plant pharmacologicals, which may produce various reactions in the human body. The microbial contamination in these raw plant materials is common, and the radiation processing is one appropriate technique for the reduction of microorganism. In herbs used as food products, the changes in total #beta#-carotene and flavonoids upon the radiation treatment were tested. The powdered and dehydrated herbs were irradiated with "6"0Co gamma rays applying doses of 0, 10, 20 and 30 kGy. The botanical species investigated were rosemary (Rosmarinus officinalis Linne), watercress (Nasturtium officinale R. Br), artichoke (Cynara scolymus ...

International Nuclear Information System (INIS)

The authors describe a new method which makes it possible to determine the radial distribution of the diffuse component of galactic gamma rays outside the solar circle. They use the observation that a good correlation exists between gamma-ray intensities and total column densities of the local interstellar gas and that the fractional column density of H_2<0.1 HI outside the solar circle. Thus the gamma-ray intensities are shown to be proportional to N(HI). The authors use the kinematics of the HI to determine the distances from which various fractions of the emission originate in the second and third galactic quadrants. Preliminary results of our analysis show that a significant flux of gamma rays originates from distances as large as 18 kpc from the galactic centre. (Auth.).

Energy Technology Data Exchange (ETDEWEB)

We construct the time-dependent radiation model for the pulsar wind nebulae (PWNe), assuming that leptons are accelerated in resonant scattering with heavy nuclei, which are injected into the nebula by the pulsar. The equilibrium spectra of these particles inside the nebula are calculated taking into account their radiation and adiabatic energy losses. The spectra of {gamma}-rays produced by these particles are compared with the observations of the PWNe emitting TeV {gamma}-rays and predictions are made for the expected {gamma}-ray fluxes from other PWNe. Expected neutrino fluxes and neutrino event rates in a 1 km{sup 2} neutrino detector from these nebulae are also calculated. It is concluded that only the Crab Nebula can produce a detectable neutrino event rate in the 1 km{sup 2} neutrino detector. Other PWNe can emit TeV {gamma}-rays on the level of a few percent of that observed from the Crab ...

Energy Technology Data Exchange (ETDEWEB)

A complete code based on the finite element method (FEM) is used to study the attenuation of gamma rays, of source energy 9 MeV, in simple homogeneous lead and water systems. The results are compared, in tables and graphs, with those produced by a Monte Carlo method of solution. In the comparison, particular attention is paid to the annihilation gamma rays generated by the pair production process, to energy deposition, and to the leakage spectra. A model, multilayer, slab shield, having a fission neutron source impinging on the left-hand face, is also solved by the FEM code, using data from a coupled neutron/gamma ray cross section library. The resulting neutron and gamma ray flux distributions, and the leakage spectra, are shown graphically. (author).

International Nuclear Information System (INIS)

75 mg (NH_4)_6Mo_7O_24 #centre dot# 4H_2O solution was irradiated for 20 min in miniature neutron source reactor (MNSR) and cooled for 12 min. In the conditions of 0.8 mol/L HNO_3, phase ratio 1:1, the solution of "1"0"1Tc sample was extracted twice with #alpha#-benzoin oxime/ethyl acetate phase to remove "1"0"1Mo and a radiochemically pure and carrier-free "1"0"1Tc product was obtained. The half-life of "1"0"1Tc was accurately measured with a HPGe #gamma#-detector by following 306.8 keV #gamma#-ray about 150 min, and processed the data by three methods, R-value method, iterative method and translation method. Five parallel measurments gave a half-life (14.02 #+-# 0.01) min (n=5) for "1"0"1Tc. (authors)

International Nuclear Information System (INIS)

Thermal analysis testing revealed slight weight changes, which were a function of gamma irradiation, in a highly reduced Defense Waste Processing Facility (DWPF) simulated waste glass. Transmission electron microscopy (TEM) was performed on this glass to determine if the weight change corresponded to microstructural variations. TEM analyses showed that no microstructural changes were attributable to gamma irradiation. Exposure of the samples to the electron beam in the TEM did cause changes in the glass microstructures in some cases. These changes were likely due to localized heating of the glass due to interactions with the transmitted electrons.

Energy Technology Data Exchange (ETDEWEB)

The effects of gamma and e-beam irradiation on mechanical and structural properties of nylon 66 (Ny 66), nylon 6 (Ny 6) and poly(ethylene terephthalate) (PET) fabrics used in tyres were investigated. The untreated (greige), treated cords and calendered fabrics were irradiated at different doses. It is found that the effects of high energy irradiation on greige, treated cords and calendered fabrics are similar. No protective effect of compounds used in calendering was observed against radiation-induced oxidative degradation. The deterioration effect of gamma irradiation on mechanical properties is much higher than that of e-beam irradiation for all types of samples. Limiting viscosity numbers of both gamma and e-beam irradiated nylon 6 and nylon 66 cords were found to decrease with increasing dose. It ...

International Nuclear Information System (INIS)

Radiation exposure of members of the public can be increased appreciably by the use of building materials containing above-normal levels of natural radioactivity. This phenomenon has attracted attention in recent years, and in this review, an attempt is made to the quantify exposures incurred under various circumstances. The second section of the review is a general survey of those building materials, mostly industrial wastes, that have aroused interest in Member countries. The probability that environmental pressures may cause such wastes to be used more and more by building industries may lead to similar situations in the future. Other review material of a relevant nature is described in the third section. Primordial radionuclides only are considered here. They are: potassium-40 (K-40); radium-226 (Ra-226) and its decay products; the series headed by thorium-232 (Th-232). The important radiological consequences of the natural radioactivity in building materials are two-fold, ...

Science.gov (United States)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma ...

International Nuclear Information System (INIS)

... kev range 10-100 kev range 100-1000 man mev range 01-10 personnel

Energy Technology Data Exchange (ETDEWEB)

Decay processes of H{sub 2}{sup -} anions in {gamma}-rays-irradiated solid parahydrogen were studied by using ESR spectrometer. The following interesting results were obtained. First, the initial amount of ortho-H{sub 2}{sup -} anions in the {gamma}-irradiated solid parahydrogen was three times as large as those of para-H{sub 2}{sup -} anions. Second, the amount of para-H{sub 2}{sup -} anions decreases faster than that of ortho-H{sub 2}{sup -} anions upon storage of the irradiated samples at 4.2 K. Third, the decay rate of H{sub 2}{sup -} anions is accelerated by the addition of D{sub 2} molecules. Forth, H{sub 2}{sup -} anions at 2.2 K decay faster than at 4.2 K. According to the parity conservation rule in a homonuclear diatomic molecule, the energy of ortho-H{sub 2}{sup -} anions at the ground state is lower than that of para-H{sub 2}{sup -} anions, whereas that of ortho-H{sub 2} molecules is higher than that of ...

International Nuclear Information System (INIS)

The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by ...

International Nuclear Information System (INIS)

Spices and packaging materials were exposed to gamma irradiation at a dose of 10 KGy. Luncheon was prepared with irradiated or non-irradiated spices. Prepared luncheon was packaged in irradiated or non-irradiated packaging materials. Packaged luncheon was treated with 2 KGy. Treated and untreated packaged luncheon were kept in a refrigerator (1-4 Centigrade) for 12 months. Microbiological, nutritive and chemical characteristics of luncheon were evaluated after processing and during storage; whereas, sensory quality was evaluated only after irradiation. Gamma irradiation decreased the microorganisms counts of spices, packaging materials and packed luncheon and increased the shelf-life of packaged luncheon products. No major differences in moisture, protein, fat, ph value, total acidity, lipid peroxide ...

Energy Technology Data Exchange (ETDEWEB)

In the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537, gamma irradiated hyaluronic acid (10 and 50 kGy) did not induce a significant increase in the number of revertant colonies in the presence of S9 metabolic activation system. In chromosomal aberration tests with CHO cells, gamma irradiated hyaluronic acid (10 and 50 kGy) did not result in an increase in the frequency of chromosomal aberrations. In vivo mouse micronucleus assay, gamma irradiated hyaluronic acid (10 and 50 kGy) did not show an increase in the frequency of polychromatic erythrocytes with micronuclei. These results indicate that hyaluronic acids irradiated at 10 and 50 kGy did not show any genotoxic effects under these experimental conditions. In order to evaluate their possible subacute toxicity, the male and female of ICR mouse were given to ...

International Nuclear Information System (INIS)

Development of food preservation and processing techniques by radiation was performed. Gamma irradiation at 2-10 kGy is considered to be an effective method to control pathogenic bacteria in species including Escherichia coli O157:H7. Gamma irradiation at 5 kGy completely eliminated pathogenic bacteria in beef. Gamma irradiation at such doses and subsequent storage at less than 4 deg C could ensure hygienic quality and prolong the microbiological shelf-life resulting from the reduction of spoilage microorganisms. Gamma irradiation on pre-rigor beef shortens the aging-period, improves tenderness and enhances the beef quality. And, a new beef processing method using gamma irradiation, such as in the low salt sausage and hygienic beef patty was developed. Safety tests of ...

International Nuclear Information System (INIS)

The results that can be expected by e#gamma# and #gamma##gamma# colliders in future are summarized. e#gamma# and #gamma##gamma# colliders have many fine possibilities, and are the economical selection for utilizing future e"+e"- colliders more effectively. e#gamma# and #gamma##gamma# colliders were proposed by former USSR researchers at the beginning of 1980s, but recently, the prospect of realizing future e"+e"- collision type linear accelerator projects has become high, they have become to be considered seriously as the option of remodeling them. The high energy photon beam of e#gamma# and #gamma##gamma# colliders is obtained by causing Compton reverse scattering, irradiating laser beam to the electron beam of e"+e"- accelerators. The production of #gamma#-beam is explained. As ...

CERN Document Server

2009 has been an extraordinary year for gamma-ray pulsar astronomy and 2010 promises to be equally good. Not only have we registered an extraordinary increase in the number of pulsars detected in gamma rays, but we have also witnessed the birth of new sub-families: first of all, the radio-quiet gamma pulsars and later an ever growing number of millisecond pulsars, a real surprise. We started with a sample of 7 gamma-ray emitting neutron stars (6 radio pulsars and Geminga) and now the Fermi-LAT harvest encompasses 24 "Geminga-like" new gamma-ray pulsars, a dozen millisecond pulsars and about thirty radio pulsars. Moreover, radio searches targeted to LAT unidentified sources yielded 18 new radio millisecond pulsars, several of which have been already detected also in gamma rays. Thus, currently the family of ...

International Nuclear Information System (INIS)

We report the detection of X-ray pulsations with a period of ?315.87 ms from the 2009 XMM-Newton observation for the radio-quiet ?-ray pulsar, LAT PSR J0007+7303, centered in the supernova remnant CTA 1. The detected pulsed period is consistent with the ?-ray periodicity at the same epoch found with the Fermi Gamma-ray Space Telescope. The broader sinusoidal structure in the folded light curve of the X-ray emission is dissimilar to that of the ?-ray emission, and the phase of the peak is about 0.5 shifting from the peak in the ?-ray bands, indicating that the main component of the X-rays originates from different sites of the pulsar. We conclude that the main component of the X-ray pulsation is contributed by the thermal emission from the neutron star. Although with a significantly different ...

International Nuclear Information System (INIS)

The resonant scattering of bremsstrahlung #gamma#-rays by a SrCO_3 target has been studied for #gamma#-ray energies of 5-11 MeV. Six #gamma#-transitions of energies between 6-8 MeV, which indicate six resonant states in "8"8Sr, were observed. The relative intensities of the resonantly scattered #gamma#-rays at 125 and 150"0 were found to be compatible only with the assignment of spin 1 to the six states. Radiative widths of the resonant states were deduced. The possibility that these states are components of the giant M1 resonance in "8"8Sr is discussed. (orig.).

International Nuclear Information System (INIS)

This paper presents anew design concept for a gamma irradiation plant for the continuous processing of pumpable liquids. Typical applications of such a plant include: the irradiation vulcanisation of natural latex rubber; disinfection of municipal sewage sludge for agricultural use; sterilisation of liquids in the pharmaceutical and cosmetics industries; industrial processing of bulk liquids The authors describe the design and operation of the latex irradiator now operating on a small production scale in Malaysia and proposed developments. The design allows irradiation processing to be carried out under an inert or other gaseous environment. State-of-the-art computer control system ensures the fully automatic processing operation needed by industrial computers.

International Nuclear Information System (INIS)

A time coincidence long baseline (250 km) cosmic ray detection system has been developed to search for bursts of high energy #gamma#-rays (E_0>= 10"1"3 eV) of extra-terrestrial origin. The system design incorporates the possibility of simultaneous observation over a variety of time scales between 1 #mu#s and 10 s. (Auth.).

International Nuclear Information System (INIS)

The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25 kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the present study showed that radiation treatment up to 20 kGy does not affect the antifungal and antibacterial activity of the plant. While sample irradiated at 25 kGy does showed changes in the antibacterial activity against some selected pathogens. No significant differences in the phenolic contents were observed for control and samples irradiated at 5, 10 and 15 kGy radiation doses. However, phenolic contents increased in ...

Energy Technology Data Exchange (ETDEWEB)

Detailed level and decay schemes and the experimental reaction and decay data on which they are based are presented for nuclei with mass number A = 242; the experimental data are evaluated. Adopted values for level and ..gamma..-ray energies, ..gamma..-intensities, as well as other nuclear properties are given.

International Nuclear Information System (INIS)

The facilities in the Institute for Nuclear Research at Pitesti allow the testing, handling and examination of nuclear fuel and irradiated materials. The most important facilities are the TRIGA Steady State Research and Material Test Reactor and the Post-Irradiation Examination Laboratory (PIEL). The purpose of this work is to determine by post-irradiation examination, the behavior of CANDU fuel, irradiated in 14 MW TRIGA reactor. The fuel was irradiated in power ramp conditions. The results of post-irradiation examination are: - Visual inspection and photography of the outer appearance of sheath; - Profilometry (diameter, bending, ovality) and length measuring; - Determination of axial and radial distribution of the fusion products activity by gamma scanning and tomography; - Microstructural characterization by metallographic and ...

Energy Technology Data Exchange (ETDEWEB)

Medicinal plants i.e. dried seeds of myristica argentea, myristica fragrans, coriandrum sativum and foeniculum vulgare were stored for 0 and 6 months, with and without gamma irradiation at 5 kGy. No detectable changes were seen in infrared and UV spectra, GLC chromatograms and refraction indices of steam distilled, essential oils from the irradiated medicinal plants. The same results were also obtained from irradiated samples stored for 6 months at ambient conditions. Storage for 6 months caused significant changes in the gas liquid chromatograms and UV spectra of all samples compared to non-stored samples. The moisture content of all samples packed in polyethylene bags seems to be constant after 6 months of storage. No measurable changes were found in the amount of essential oil content caused by irradiation.

Energy Technology Data Exchange (ETDEWEB)

This paper describes the research and development activities in three areas of radiation processing, namely: food irradiation, medical product sterilization and wood plastic combination. Plans and efforts exerted to acquire a larger gamma source to augment our present 5,000 curie source are discussed. Cost estimates for a radiation facility are presented on the basis of the market potential of food irradiation and medical product sterilization. Existing local industries that can benefit from the adaptation of irradiation technology in their processing requirements are described.

British Library Electronic Table of Contents (United Kingdom)

The mechanism of abrupt increase of the giant magneto impedance (GMI) ratio in the ion irradiated Co-based amorphous ribbon has been investigated. The grazing incident X-ray diffraction and transmission electron microscope were used to characterize the samples before and after ion irradiation. The GMI-ratio considerably increased in the ion irradiated samples and the GMI response showed strong dependence on the driving frequencies. The Barkhausen noise (BN) signals are increased for the Ar ion irradiated sample with dose of 1x10^1^7 ion/cm^2. The results are interpreted in terms of GMI variation associated with domain wall dynamics.

International Nuclear Information System (INIS)

The flight line profile data and statistical analysis results for the Port Alexander Quadrangle in southeast Alaska are presented.

Energy Technology Data Exchange (ETDEWEB)

A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements.

Science.gov (United States)

A series of experiments is to be made during the acceptance test program of the Fast Flux Test Facility (FFTF) to measure the gamma ray characteristics of the Fast Test Reactor (FTR) and to establish the performance characteristics of the reactor shield. These measurements are a part of the FFTF Reactor Characterization Program (RCP). Detailed plans have been developed for these experiments. During the initial phase of the Characteristics Program, which will be carried out in the In-Reactor Thimble (IRT), both active and passive measurement methods will be employed to obtain as much information concerning the gamma ray environment as is practical. More limited active gamma ray measurements also will be made in the Vibration Open Test Assembly (VOTA).

International Nuclear Information System (INIS)

The #gamma# rays following the #beta# decays of "8"8Kr and "8"8Rb have been studied, using both large volume Ge(Li) detectors for singles and coincidence measurements and anti-Compton spectrometry for singles measurements. Level schemes for "8"8Rb and "8"8Sr were constructed from the data and 74 of 81 #gamma# rays observed in the decay of "8"8Kr were placed in the "8"8Rb level scheme with 23 excited states. For the decay of "8"8Rb, all of the observed 27 #gamma# rays have been placed in the (well known) level structure of "8"8Sr. Spin and parity assignments have been deduced from #beta#-decay logft values and #gamma#-ray transition patterns. Possible shell model interpretations are presented for the level schemes.

British Library Electronic Table of Contents (United Kingdom)

E-beam and gamma products from the radiolysis of aqueous solutions of (+-)-metoprolol tartrate, saturated in nitrogen, are analyzed by HPLC with on-line mass and UV detectors. The structures of 10 radiolytic products common to e-beam and gamma irradiations are elucidated by comparing their fragmentation pattern to that of (+-)-metoprolol. Two of the radiolytic products are also metabolites. Different routes for the formation of the radiolytic products are proposed.

International Nuclear Information System (INIS)

Sentinel node (SN) scintigraphy for cervical and vulvar cancer guides the gynaecological oncologist in finding the metastatic lymph nodes during lymphadenectomy. The role of the surgical gamma probe in the sentinel node concept in gynaecological oncology is to localise (SN) both intra-operatively and transcutaneously. Intra-operative hand-held collimated gamma probes are increasingly used for detection of the sentinel lymph node. A comparative evaluation of handheld gamma probes: Neoprobe 1500, Europrobe, Gamma Finder, Gamma Ray Prospector GRP1 and GPR2 was performed using different detection methods. Laboratory tests were performed in which sensitivity, spatial resolution and angular sensitivity were evaluated. The results for each gamma probe were summarised and discussed. Awareness of a gamma probes capabilities and ...

CERN Document Server

The nature of the hard X-ray source XSSJ12270-4859 is still unclear though it was claimed to be a magnetic Cataclysmic Variable. We here present a broad-band X-ray and gamma ray study based on a recent XMM-Newton observation and archival INTEGRAL and RXTE data. From the Fermi/LAT 1-year point source catalogue, we tentatively associate XSSJ12270-4859 with 1FGLJ1227.9-4852, a source of high energy gamma rays with emission up to 10GeV. We complement the study with UV photometry from XMM-Newton and ground-based optical and near-IR photometry. The X-ray emission is highly variable showing flares and intensity dips. The X-ray flares consist of flare-dip pairs. Flares are also detected in the UV range but not the dips. Aperiodic dipping behaviour is also observed during X-ray quiescence but not in the UV. ...

International Nuclear Information System (INIS)

local peanut cultivars Giza 4 and Giza 5 were exposed to different doses ( 50,100,150,200,250 and 300 Gy)to Co "6"0 gamma ray source . all irradiated materials were cultivated to give the M_1 and M_2 generation , then high yielding mutants were selected from the M_2 generation and cultivated separately to give the M_3 generation. some yield component traits were measured for the three generations (M_1,M_2 and M_3) and M_3 families.variations observed in these traits were attributed to genetic factors. the M_3 selected mutants were artificially infected by aspergillus flavus L spores (aflatoxins-B1 and B2 groups-producer strain). aflatoxin concentrations were estimated and the analysis showed that aflatoxin concentrations in seeds of the M_3 selected mutants from cultivar Giza 4 were higher than those in seeds of the M3 mutants selected from cultivar Giza 5. however, the concentration of aflatoxin increased when the yield ( ...

Energy Technology Data Exchange (ETDEWEB)

The excitation function of the {sup 64}Ni({alpha},p){sup 67}Cu reaction was measured from threshold up to 24 MeV in order to investigate the possibility of production of the {beta}{sup -}-emitting therapeutic radioisotope {sup 67}Cu (T{sub 1/2}=61.9 h). Two stacks of thin metallic self-supporting foils of {sup 64}Ni (enrichment 77.8%) prepared by electrolytic deposition were irradiated by {alpha}-particle beams. The radioactivity was determined via HPGe detector {gamma}-ray spectrometry. Some {sup 67}Ga activity (which emits the same {gamma}-rays as {sup 67}Cu), formed via the {sup nat}Cu({alpha},x){sup 67}Ga process on trace copper impurity in the Ni foils, was also observed. Corrections were done for {sup 67}Ga activity contribution and for the {sup 67}Cu activity escape fraction from the thin Ni-foil. The maximum cross section of the {sup 64}Ni({alpha},p){sup 67}Cu reaction amounts to 34 mb at 22 MeV. The experimental ...

International Nuclear Information System (INIS)

A large matrix of simple alloys and complex commercial type steels was irradiated over a range of fluxes at 60 FC up to a fast fluence of about 3 x 10"2"2 n/m"2. Combined with data in the literature, these results show a negligible effect of flux on irradiation hardening in the range of 2 x 10"1"3 to 5 x 10"1"8 n/m"2-s. This observation lends indirect support to the proposal that the accelerated embrittlement in the High Flux Isotope Reactor surveillance steels was due to an anomalously high level of damage from gamma rays. A weak dependence of hardening on a number of elements, including copper, nickel, phosphorus, molybdenum and manganese, can be described by a simple empirical chemistry factor. Particular combinations of elements resulted in hardening differences of up to about 60% in the complex commercial type steels and up to about 100% in simple model alloys. Direct effects of microstructure ...

Energy Technology Data Exchange (ETDEWEB)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L{sub {gamma}1} X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L{sub {gamma}1}/L{sub {beta}1} X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The proposed short wavelength coherent light source driven by the SLAC 3 km linac might be used to induce transitions between nuclear isomeric states. If an isotope were found with energetically adjacent isomeric states, one short-lived and one long-lived, and it were possible to separate and concentrate the long-lived species, and other nuclear and solid-state parameters were favorable, it might be possible to convert sufficient population to the short-lived state to realize [gamma]-ray lasing. Even if the x-ray intensity were insufficient, study of such driven transitions would be quite valuable.

International Nuclear Information System (INIS)

The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the ...

Energy Technology Data Exchange (ETDEWEB)

The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the only major protection to astronauts from harmful exposure. Unlike low-linear energy transfer (LET) {gamma} or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure, since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. The Bragg curve does not necessarily represent the biological damage along the particle traversal, and the 'biological Bragg curve' is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. Here we used a unique irradiation geometry to measure the biological response across the Bragg curve in human fibroblasts exposed to ...

International Nuclear Information System (INIS)

The present investigation was conducted at Ismaillia Research Station-Agricultural Research Center, Ismaillia Governorate, during the two successive seasons of 2000 and 2001. Two varieties of peanut (Arachis hypogaea L) namely Giza 4 and Giza 5 were treated with gamma ray doses; 10,15, 20, 25 Kr in order to induce genetic variability and to study the importance of the relative contribution of peanut yield components by employing some statistical procedures, i.e. simple correlation, multiple linear regression and stepwise regression analysis. The results showed that, there was significant positive correlation between seed yield/plant and no. of pods/plant, 100 seed weight, shelling percentage and pod yield/plant, and there was significant positive correlation between pod yield/plant and no of seed/plant,100 pod weight and 100 seed weight. The multiple linear regression analysis clearly showed that the relative contribution (R"2%) of the yield ...

International Nuclear Information System (INIS)

The world fusion program has advanced to the stage where it is appropriate to construct a number of devices for the purpose of burning DT fuel. In these next-generation experiments, the expected flux and fluence of 14 MeV neutrons and associated gamma rays will pose a significant challenge to the operation and diagnostics of the fusion device. Radiation effects include structural damage to materials such as vacuum windows and seals, modifications to electrical properties such as electrical conductivity and dielectric strength and impaired optical properties such as reduced transparency and luminescence of windows and fiber optics during irradiation. In preparation for construction and operation of these new facilities, the fusion diagnostics community needs to work with materials scientists to develop a better understanding of radiation effects, and to undertake a testing program aimed at developing workable solutions for ...

Energy Technology Data Exchange (ETDEWEB)

The polymerization of vinyl pyrrolidinone on nylon 66, with the assistance of aqueous phenol and formic acid, was investigated by mutual and post irradiation procedures. Both solvents were found to greatly facilitate the polymerization with the post irradiation procedure, whereas neither presented any advantage with the mutual irradiation procedure. Tensile properties of the modified fibers were affected in similar ways by both the irradiation procedures and solvents in that the only notable changes were the somewhat higher extensions at yield and at break. The moisture regain values of the treated yarns and fabrics were increased up to three-fold. Surface morphology of the modified fibers was revealed by SEM.

International Nuclear Information System (INIS)

This study was carried out to evaluate the effects of irradiation (gamma irradiation at dose levels of 0.0, 2.5, 5.0, 10.0 or 20.0 kGy, He-Ne and their combination) on nutritive characteristics of Vicia faba L. seeds (Giza 843). Analyses included levels of anti-nutrients (total phenolic compounds, tannins, phytic acid, trypsin inhibitor and vicine), chemical composition (sugars, crude proteins, fat, dry matter and ash) and fatty acids profile. All treatments caused significant (P<0.05) decreases in the antinutrational factors under investigation. The reduction in the content of tannins and phenolic compounds were more pronounced with He-Ne alone or He-Ne in combination with gamma irradiation. At dose levels 10.0 and 20.0 kGy without or with combination of He-Ne were more efficiency in the reduction of phytic acid content by 24.3, 32.8, 34.5 and 45.5 %, respectively. Also, for ...

Energy Technology Data Exchange (ETDEWEB)

Thermoluminescence of inorganic dust extract from herbs and spices has been demonstrated to be a useful method to discriminate irradiated food products as well as to estimate the total dose exposure. The time evolution of infrared stimulated luminescence has been systematically investigated in potassium feldspar and albite minerals subjected to different doses of gamma irradiation (ranging from 0 to 8 kGy). Experimental results reveal a 300-600 nm signal which is greatly intensified for irradiated samples, following the same irradiation dose dependence observed in thermoluminescence. The luminescence intensity disappears after few seconds of illumination, following a time evolution which is proportional to (1 + Bt){sup -P}. The influence of both B and P factors upon the irradiation dose has been systematically analysed. (author)

International Nuclear Information System (INIS)

The ability of a local strain of grape phylloxera to develop and reproduce on irradiated in vitro cultured rootstocks (Ru140, R99 and 3309C and one local variety 'Helwani' was determined. The results showed that there was great variation in developmental time and reproduction of phylloxera between irradiated and unirradiated in vitro cultured plants. Survival, number of eggs and mean developmental time were greatly reduced when phylloxera was reared on irradiated rootstocks. Based on the examined biological parameters of phylloxera, all tested rootstocks would be more resistant toward such destructive insect when they were irradiated. Thus, phylloxera resistance was enhanced when in vitro cultured plants were treated with low doses of gamma irradiation. (author)

CERN Document Server

In this work we develop a new propagation model for the Galactic cosmic rays based on the GALPROP code, including contributions from dark matter annihilation. The model predicts compatible Galactic diffuse $\\gamma$ ray spectra with EGRET data in all sky regions. It also gives consistent results of the diffuse $\\gamma$ ray longitude and latitude distributions. Further the results for B/C, $^{10}$Be/$^9$Be, proton, electron and antiproton spectra are also consistent with cosmic ray measurements. In the model we have taken a universal proton spectrum throughout the Galaxy without introducing large fluctuation for the proton energy loss is negligible. The dark matter annihilation signals are `boosted' after taking the contribution from subhalos into account. Another interesting feature of the model is that it gives better description of the diffuse ...

Energy Technology Data Exchange (ETDEWEB)

The fully depleted pn-junction charge coupled device (pn-CCD) has been developed as a detector for X-ray imaging and high-resolution spectroscopy for the X-ray satellite missions XMM and ABRIXAS. If the detector is exposed to a particle radiation environment, the energy resolution is degraded due to charge transfer losses and a dark current increase. In a first experiment, prototype devices were irradiated with 10 MeV protons. After completion of the detector development, the proton irradiation was repeated for a quantitative study of the radiation damage, relevant for the satellite missions. The irradiation test was extended by a 5.5 MeV {alpha}-particle and a 6 keV X-ray exposure of the pn-CCD, including the CAMEX preamplifier chip.

Energy Technology Data Exchange (ETDEWEB)

New measurements of relative gamma-ray emission probabilities in the decay of [sup 101]Mo and [sup 101]Tc are reported. Previously published conversion-electron data have been used along with the gamma-ray data to formulate self-consistent decay schemes. (orig.)

Energy Technology Data Exchange (ETDEWEB)

An imaging detector for {gamma}-rays ({approx equal}1 MeV) based on minicell MWPCs with converters and a position resolution of {Delta}x=0.5 mm has been developed and tested. Very high rate capability (>10{sup 8}/cm{sup 2} s) and a special readout for suppression of scattered radiation are implemented allowing to enhance the measured contrast. The relevant physical processes are discussed and first pictures are presented. (orig.).

International Nuclear Information System (INIS)

several authors tried to drive codes to construct nuclear level scheme of nuclei using a set of measured gamma -ray transitions and known energy levels, Ritz combination principle proved to be useful in constructing a more complete decay scheme. In this thesis the energy level schemes of some nuclei have been investigated by the measurements of the gamma - ray energies and use of Ritz combination code. The nuclei under investigation are "110m Ag (253 d)"110 Cd and "166m Ho (1200 yr) "166 E r. On the basis of the suggested level at 2249.02 keV by the Ritz code new positions of the two gamma-ray transitions at 677.5 and 706.6 KeV are found in decay scheme of "110m Ag. Also by this code, new position for the 994.84 KeV gamma-ray transition were established to depopulate the level at 1075.2 KeV.

International Nuclear Information System (INIS)

The crabbing of an incident photon beam from a laser, and the electron beam with which it interacts at the conversion point, is shown to have the same efficiency as in head-on Compton scattering, but with the advantages of a crossing geometry. The resulting #gamma#-ray beam is also crabbed, which allows for a crossing collision point, while maintaining the luminosity at the same value it would have in a head-on collision.

International Nuclear Information System (INIS)

The crabbing of an incident photon beam from a laser, and the electron beam with which it interacts at the conversion point, is shown to have the same efficiency as in head-on Compton scattering, but with the advantages of a crossing geometry. The resulting #gamma#-ray beam is also crabbed, which allows for a crossing collision point, while maintaining the luminosity at the same value it would have in a head-on collision. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

The paper describes an application of the tree classification method Random Forest (RF), as used in the analysis of data from the ground-based gamma telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to be discriminated against a dominating background of hadronic cosmic-ray particles. We describe the application of RF for this gamma/hadron separation. The RF method often shows superior performance in comparison with traditional semi-empirical techniques. Critical issues of the method and its implementation are discussed. An application of the RF method for estimation of a continuous parameter from related variables, rather than discrete classes, is also discussed.

Science.gov (United States)

... the hydroxyl group with the benzene ring. The molar extinction coefficients for the various species at their respective absorption ... Glya Recorded by 1H-NMR Spectroscopy TABLE 2 Molar Extinction Coeff...

International Nuclear Information System (INIS)

Described and discussed in this paper are radiation processes and their advantages over the conventional techniques. Radiation sterilization of medical products, food irradiation, wood plastic composites, and radiation treatment of sewage and waste waters are presented. The Philippine experience in using these technologies, its problems and barriers are also given. (ELC).

Energy Technology Data Exchange (ETDEWEB)

{gamma}-ray excitation functions have been measured for the interaction of fast neutrons with {sup 48}Ti (neutron energy from 1 MeV to 250 MeV). The Los Alamos National Laboratory spallation neutron source, at the LANSCE/WNR facility, provided a ''white'' neutron beam which is produced by bombarding a natural W target with a pulsed proton beam. The prompt-reaction {gamma} rays were measured with the large-scale Compton-suppressed Ge spectrometer, GEANIE. Neutron energies were determined by the time-of-flight technique. Excitation functions were converted to partial {gamma}-ray cross sections, taking into account the dead-time correction, the target thickness, the detector efficiency, and neutron flux (monitored with an in-line fission chamber). The data analysis is presented here for neutron energies between 1 to 20 MeV. Partial {gamma}-ray cross ...

Energy Technology Data Exchange (ETDEWEB)

Wood-plastic combination (WPC) was produced by {gamma}-irradiation of persimmon impregnated with acrylonitrile and styrene. The hardness and strength of WPC obtained were higher than those of an unmodified wood. Thus, it was found that the WPC is suited for a head of golf club, because the Shore hardness value of WPC is 36% greater than that of unmodified wood. An impregnation method of monomers with some pigments could produce colored WPC without diminishing natural grain. Head of golf club could be manufactured from colored WPC in practice. (auhtor).

International Nuclear Information System (INIS)

Spectra of e.p.r. radicals in cellulose and timber gamma-irradiated at 77 and 300 K have been measured. Radiation yields and the kinetics of radicals accumulation have been studied. The effect of ionizing radiation on cellulose is the appearance of radicals resulting from rupture of C-H bonds in positions 1 and 4. Timber, additionally, forms ''lignin'' radicals. A mechanism of cellulose and timber radiolysis is suggested. ''Lignin''-type compounds present in timber protect polysaccharides from radiation-induced destruction.

Energy Technology Data Exchange (ETDEWEB)

The purified integral membrane protein, band 3, from human erythrocytes was inserted into egg lecithin liposomes. The insertion of band 3 was determined from thermal transition data from the analysis of the C-H stretching region bands recorded at temperatures from 25 to -22[sup o]C. Raman spectra show that band 3 considerably broadens and lowers the thermal transition of egg lecithin liposomes, suggesting the insertion of band 3. The band 3-inserted liposomes were irradiated with gamma-rays (40 Gy) and the radiation target groups were determined by the analysis of the structural sensitive Raman bands in the 1600-1700 cm[sup -1] (amide I), 1200-1300 cm[sup -1] (amide III) and 550-1030 cm[sup -1] (side chain amino groups) regions. The radiation-sensitive groups as identified from Raman spectra in the region 550-1030 cm[sup -1] are tyrosines and cysteines. The radiation-induced changes in the secondary structure were determined from amide I and ...

CERN Document Server

The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after the burst, indicative of a jet break. The timing of the jet break combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 2.5 degrees. We derive an empirical `time-lag' redshift from the BAT data of z_hat = 0.69 +/- 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modelled by a simple power law with index alpha = -1.2. However after 300s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that ...

Energy Technology Data Exchange (ETDEWEB)

In this study, the effects of 325nm wavelength ultraviolet light irradiation on pitting corrosion behavior of type 340 stainless steel in a neutral chloride solution are studied. Further, the change of passive film with the light irradiation is analyzed using x-ray photoelectron spectroscopy. The mains results obtained therefrom are stated below. Pitting potential can be shifted in noble direction by the ultraviolet light irradiation. The effect of ultraviolet light irradiation is ore prominent in the pitting corrosion process than that in the passive film formation. The result of the analysis in terms of the birth and death stochastic probability process shows that pitting corrosion rate is decreased remarkably by the ultraviolet light irradiation at the formation of passive film, while the repassivation is slightly expedited by the ultraviolet light ...

International Nuclear Information System (INIS)

The main objective of the present thesis was develop and get operational a real-time neutron radiography system, at the IPEN-CNEN/SP. This system is installed inside the shielding of an old facility, designed in 1988, for film radiography, which is installed at the beam-hole 08 of the 5 MW, IEA-R1 Nuclear Research Reactor. The most important modifications at the such facility were the increase of the #gamma#-radiation filter thickness, increase of the inner area of the shielding, design of a neutron collimator and a light tight box. The main characteristics of the neutron beam at the irradiation position are: flux: 1 x 10"6n/cm"2s, collimation ratio 70, effective energy 7 meV, diameter 20 cm, neutron/#gamma# ratio #approx# 10"6n/cm"2mrem. The real-time images have been obtained by means of an imaging system that consists of a screen scintillator, a light intensifier, a video camera, a digitizing frame grabber and a ...

Energy Technology Data Exchange (ETDEWEB)

In this experiments, we established long-termed culture methods of bone marrow stromal cells for proliferation and differentiation of stem cells. And we selected some extracts which support maximal proliferation of stromal cells with this method. We conformed the synergic effects of herbal mixture extracts for stromal cell growth. The proliferation of stromal cells was increased rather by the addition of mixture extracts than by addition of single strain extract. In the previous and cooperative experiments, we selected complex extracts (Him-I, Him-II) which increased the number of nonadherent mononuclear cells. Different cytokine expression patterns were observed stromal cells cultured in the presence or absence of mixture extracts which support differentiation of nonadherent cells. Some fractions of Him-I and Him-II increased the proliferation of bone marrow cells irradiated {gamma}-ray(4Gray). Stimulation of macrophage cell line with herval ...

International Nuclear Information System (INIS)

Airborne lead particulates collected on a membrane filter were determined by the nondestructive X-ray fluorescence method. The gamma/X radionuclide source "2"4"1Am/Ag and a scintillation detector with a NaI/Tl crystal were used for the excitation and detection, respectively, of L X-rays of Pb. One can say, with reference to the obtained results, that the sensitivity and accuracy of the measurement is more than adequate for monitoring the Pb level in air. (author).

International Nuclear Information System (INIS)

Radicals formed in gamma-irradiated crystals of galactose and glycine were found, upon dissolution, to cause mutagenesis of Salmonella typhimurium strains TA-98 and TA-100. Although the reproducibility of the results has not been adequately determined, they suggest the possibility of developing a test to measure the mutagenic-carcinogenic potential of radiation-induced free radicals with a microbial system.

Science.gov (United States)

Amorphous Pd/sub 80/Si/sub 20/ was irradiated with fast neutrons (>1 MeV) to a fluence of 5 x 10/sup 20/ neutrons/cm/sup 2/. X-ray scattering intensities were measured before and after the irradiation with monochromatic Cu-K..cap alpha../sub 1/ rays. Scattered intensities for s>0.4 A/sup -1/ (s=2 sintheta/lambda) proved unaffected, while intensities were found remarkably enhanced for s<0.4 A/sup -1/ after the irradiation, i.e., in the small-angle region and the leading edge of the first halo. The results are discussed in relation to the structural anomalies in amorphous solids.

Energy Technology Data Exchange (ETDEWEB)

Several configurations of moderating and shielding materials have been designed and measured on the LVR-15 reactor for boron neutron capture therapy (BNCT) purposes. To determine the neutron and gamma ray space-energy distributions in the cylindrical geometry, the two-dimensional code DOT with the coupled neutron-gamma data library DLC-36 was used. The experimental verification of the beam parameters was performed in the LVR-15 reactor thermal column empty space with layers of graphite, aluminium, alumina, lead and bismuth. Attention was paid to establishing techniques and instrumentation for monitoring the neutron and gamma ray dose and beam quality. The thermal and epithermal flux densities were measured by activation foils, the neutron spectrum was determined with a Bonner spectrometer and gamma ray background with a scintillation ...

International Nuclear Information System (INIS)

A simulated hull monitoring system based on passive #gamma# ray scanning was set-up in K-01 hot-cell, which consists of a simulated hull basket, a collimator system, a 150 cm"3 HPGe detector and an ORTEC-919 multichannel buffer-computer system. Six different kinds of experimental set-up were established to simulate the variations of #gamma# ray source term distribution (partly concentration) and the variations of matrix density (+46.1%). The experimental results show that the biases of peak area is better than -25.3% for "1"3"7Cs 662 keV #gamma# rays and -18.6% for "1"4"4Ce-"1"4"4Pr 2186 keV #gamma# rays. The hardness of pulse height spectrum is demonstrated to show that the peak area ratio of 2186 keV to 662 keV varies from 380 to 72 when the thickness of lead filter varies form 5 mm to 30 mm. Also studied are the ...

Energy Technology Data Exchange (ETDEWEB)

A theoretical model is developed to explain variations in airborne gamma-ray measurements over a calibration range near Ottawa, Ontario. The gamma-ray flux from potassium and the thorium decay series showed an expected decrease with increasing soil moisture. However, the gamma-ray flux from the uranium decay series was highest in the spring when the ground was water-saturated and even covered with snow. These results are explained through the build-up of radon and its associated gamma-ray-emitting decay products in the clay soil of the calibration range with increasing soil moisture. Similar results were found from airborne measurements over other clay soils. However, measurements over sandy soils showed that the count rates from all three radio elements increased with decreasing soil moisture. This difference between soil types was attributed to the lower radon emanation of the more coarse-grained ...

Energy Technology Data Exchange (ETDEWEB)

The young open cluster Berkeley 87 was predicted to be associated with the COS B {gamma}-ray source 2CG 075+00 on the basis of the experimental evidence of the presence of a shock front around the Wolf - Rayet star ST3 placed in the inner part of the cluster. The CGRO phase-1 data confirm this identification. Protons accelerated at the shock boundary can produce {pi} deg. via p-p interactions and then {gamma}-rays. With the measured flux F{sub {gamma}} (E > 100 MeV) {approx_equal} 9x10{sup -7} ph cm{sup -2} s{sup -1} and the power-law proton spectrum with spectral index {gamma} = 2, the cosmic-ray-energy-density in the inner part ({approx} 0.8 pc radius) of Berk 87 is about 100 times greater than that in the vicinity of the Earth. We have calculated {gamma}-ray spectra expected from the decay of {pi}{sup d}eg. produced in p-p interactions. The spectra ...

Energy Technology Data Exchange (ETDEWEB)

The thermal neutron capture cross sections and the neutron capture resonance integrals of {sup 241}Am leading to the production of the isomer {sup 242m}Am and the ground-state {sup 242g}Am were measured radiochemically by the Cd-ratio technique with neutron flux monitors of Co/Al and Au/Al alloy. Highly-purified {sup 241}Am targets were irradiated in an aluminum capsule by using JMTR. The neutron fluxes and their epithermal neutron fractions were determined by measuring {gamma}-rays of {sup 60}Co and {sup 198}Au. The yields of {sup 242m}Am and {sup 242g}Am were decided by analyzing growth and decay curves of the {alpha}-ray activity ratios {sup 242}Cm/{sup 241}Am. The resultant thermal neutron capture cross sections are 85.7 {+-} 6.3 b and 768 {+-} 58 b for {sup 242m}Am and {sup 242g}Am, and the resonance integrals 114 {+-} 7 b and 1,694 {+-} 146 b, respectively. The differences between the present results and the evaluated ...

Energy Technology Data Exchange (ETDEWEB)

Hyperquenching of liquid water with cooling rates of 10{sup 6}-10{sup 7} K s{sup -1} yields glassy water. Upon {gamma}-irradiation at 77 K, the only paramagnetic species accumulating in hyperquenched glassy water are the hydroxyl and hydroperoxyl radicals. There are no hydrogen atoms or electrons seen by the ESR technique. For irradiation doses up to about 70 kGy, the relative contributions of hydroxyl and hydroperoxyl radicals to the total amount of paramagnetic species remain virtually constant. The total amount of paramagnetic species, n, is sublinear in dose, d, well approximated by n=8.55x10{sup 16}d{sup 0.8} for n in spin g{sup -1} and d in kGy.

British Library Electronic Table of Contents (United Kingdom)

The collapsar scenario for long gamma-ray bursts requires rapidly rotating Wolf-Rayet stars as progenitor stars. We highlight two possible ways out of the dilemma that the strong winds of Wolf-Rayet lead to a fast spin-down. One way is to restrict the duration of the Wolf-Rayet phase to a short time span at the end of the star's evolution. We show that this appears to apply to GRB 021004. The other way is to choose a sub-solar metallicity, thus limiting the Wolf-Rayet wind efficiency. We discuss corresponding stellar evolution models and show that a metallicity limit of about 1/10th solar, as it is required by the models, may be consistent with the empirical gamma-ray burst rate.

Energy Technology Data Exchange (ETDEWEB)

Globular clusters are quite compact (size {proportional_to}10 pc) objects distributed spherically around the galaxy. They contain about 10{sup 5}-10{sup 6} mostly old stars. The number of millisecond pulsars in typical globular cluster is expected to be large (of the order of 100). We investigate the possible mechanism of production of high energy gamma-rays in those objects. Part of the wind energy of pulsars (energy conversion factor) is converted into relativistic leptons. Those leptons can upscatter in inverse Compton process low energy starlight and CMB photons and produce gamma-rays. MAGIC is an Imaging Atmospheric Cerenkov Telescopes located at Canary island of La Palma. We present results and discussion of the MAGIC observations of globular cluster M13.

Energy Technology Data Exchange (ETDEWEB)

The ASFIT (Anisotropic Source-Flux Iteration Technique) code was first developed in India about 1970 to solve the radiation transport equation represented in the form of coupled integral equations separating the spatial and energy-angular transmissions. The ASFIT code uses a nodal structure in the wavelength [lambda] domain in Compton units (CU) rather than in the energy domain. The ASFIT-VARI code is the latest version available from the Radiation Shielding Information Center. It incorporates variable dimensioning and has been adapted for use on MS-DOS personal computers using the Ryan-McFarland or Microsoft Version 5.0 FORTRAN compilers. While earlier versions used point cross sections (well suited for gamma-ray transport), the present version also allows multigroup cross sections for neutron and coupled neutron-gamma-ray transport.

International Nuclear Information System (INIS)

In the Peruvian natural forest there are several kind of woods, some of those are not of commercial interest, because have not resistance at termites and wet, are too soft, or can not be well finished, in the others. The present work is devoted to improvement of the physical properties of wood, such as hardness, traction, wet resistance, etc., by means of the generation of a composite wood-polymers cured by using gamma irradiation. The main objective is to establish the main parameters for the polymerization process (economic technical aspect) that decrease the amount of water absorption, in consequence the volumetric variation of Catahua, Mohena and Capirona woods. Gamma irradiation also provides good protection against the biological agents. In consequence, these woods increase its intrinsic and economic values. (author)

International Nuclear Information System (INIS)

The Polarized Gamma-ray Observer (PoGOLite) is a balloon-borne instrument that will measure gamma-ray polarization in the energy range 25-80 keV from astronomical sources such as pulsars, accretion discs and jets from active galactic nuclei. The two additional parameters provided by such observations, polarization angle and degree, will allow these objects to be studied in a new way, providing information about their emission mechanisms and geometries. The instrument measures azimuthal scattering angles of photons within a close packed array of phoswich detector cells (PDCs) based on coincident detection of Compton scattering and photoelectric absorption. Each PDC comprises three different scintillating components and combines photon detection, active collimation and bottom anticoincidence into one single unit. The three parts are viewed by a photomultiplier tube (PMT) and pulse shape discrimination is used to identify signals from dierent ...

International Nuclear Information System (INIS)

We study the spectral evolution of pulsar wind nebulae (PWNe) taking into account the energy injected when they are young. We model the evolution of the magnetic field inside a uniformly expanding PWN. Considering time-dependent injection from the pulsar and coolings by radiative and adiabatic losses, we solve the evolution of the particle distribution function. The model is calibrated by fitting the calculated spectrum to the observations of the Crab Nebula at an age of a thousand years. The spectral evolution of the Crab Nebula in our model shows that the flux ratio of TeV #gamma#-rays to X-rays increases with time, which implies that old PWNe are faint in X-rays, but not in TeV #gamma#-rays. The increase of this ratio is because the magnetic field decreases with time and is not because the X-ray emitting particles are cooled more rapidly than the TeV ...

International Nuclear Information System (INIS)

By the use of thermoluminescence (TL) technique we have investigated the effects of gamma irradiation on the TL response of pulverised natural zircon (ZrSiO_4) crystals from the Jos Plateau area of Nigeria. Samples of the mineral that have been previously annealed were artificially irradiated to moderate gamma doses ranging from 0.7 to 4.9 Gy using "6"0Co gamma-source of the CERD. The natural TL glow curve of the sample showed a broad peak around 250 deg. C, the peak was however, found to be completely erased following heat treatment for 2 h at 400 deg. C. The TL glow curves of the artificially irradiated samples showed two overlapping glow peaks at about 112 deg. C (peak I) and at 156 deg. C (peak II) within the dose range utilised. We note that the natural TL peak appears to be different from the two observed in the artificially irradiated ...

Energy Technology Data Exchange (ETDEWEB)

Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/..gamma.. ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time ..gamma.. spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded ..gamma.. spectra created by the photopeak-Compton edge combination in the plateau portion ...

Science.gov (United States)

Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/gamma ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time gamma spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded gamma spectra created by the photopeak-compton edge combination in the plateau portion of the knee ...

International Nuclear Information System (INIS)

Radioactive particles as well as x irradiation from an external source has been used in the treatment of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. In order to clarify effects of ionizing irradiation on synovial cells, radioactive gold ("1"9"8Au) and yttrium ("9"0Y) were added to fibroblast cultures derived from human synovial membranes. Other cultures were irradiated by a Picker x-ray machine. Fibroblast growth and hyaluronic acid production were measured. Radioactive gold and yttrium particles induced a significant increase of hyaluronic acid synthesis rate (pg/cell/day) and inhibited fibroblast growth. Fibroblasts continued to overproduce hyaluronic acid and to show growth inhibition 3 weeks after irradiation with radioactive gold. Hydrocortisone inhibited hyaluronic acid overproduction induced by radioactive gold. Overproduction of hyaluronic acid induced ...

Energy Technology Data Exchange (ETDEWEB)

The fading of irradiated and natural blue-colored pearls was investigated in this experiment. Thirty natural blue-colored pearls and sixty irradiated blue-colored pearls were used. Some of them were placed at a light position of RT. Another pearls were placed at a dark position of 50/sup 0/C. The irradiated pearls placed at a light position of RT didn't show remarkable fading in their color in 294 days. But the natural blue-colored pearls showed a little recovery from 4% to 8% in reflection factors in 223 days at RT. The irradiated pearls placed at a dark position of 50/sup 0/C showed the recovery from 9% to 14% in 264 days independently of irradiation times. The natural blue-colored pearls also showed the bleaching from 5% to 10% in reflection factor in 86 days at 50/sup 0/C. Both irradiated and natural blue-colored pearls hardly showed their ...

CERN Document Server

Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. Several signatures, ranging from the positron excess, as observed by HEAT, AMS-01 and PAMELA, the gamma ray excess, as observed by the EGRET spectrometer, the WMAP-haze, and constraints from antiprotons, as observed by CAPRICE, BESS and PAMELA, have been discussed in the literature. Unfortunately, the different signatures all lead to different WIMP masses, indicating that at least some of these interpretations are likely to be incorrect. Here we review them and discuss their relative merits and uncertainties. New x-ray data from ROSAT suggests non-negligible convection in our Galaxy, which leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a ...

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Effects of gamma irradiation on essential oils of five medicinal plants i.e. dried seeds of piper cubeba(cubeb), piper nigrum(black pepper), piper retrofractum, amomum cardamomum(cardamom) and myristica fragrans(mace), packed in low density polyethylene bag of 0.13 mm thickness have been investigated. After being irradiated at doses of 5 and 10 kGy, a part of the samples was analysed, and the rest were stored for six months at temperature of 30 +- 2 degC, and humidity ranging from 70 to 95%. The essential oil characteristics of control, irradiated and six month stored samples were analysed using infrared and ultraviolet spectrophotometers, HPLC, GLC and refractometer. Other parameters observed were moisture content and essential oil content of the samples. Results showed that irradiation up to a dose of 10 kGy do not give any significant effect on these parameters. Significant ...

Energy Technology Data Exchange (ETDEWEB)

The short range of low-energy electrons has made them suitable for the treatment of skin lesions, especially when extensive areas must be irradiated with special considerations to save the normal underlying tissue. This report covers some salient features of total body electron irradiation: the construction of the large fields required, x-ray contamination levels, and multiple-field techniques. While the investigation is essentially experimental, we also indicate the results of calculations. We conclude most generally that treatment planning with whole skin irradiations can be as precise as with smaller fields.

International Nuclear Information System (INIS)

Low-lying nuclear energy levels in "1"1"0In and "1"1"2In were determined from de-excitation #gamma#-rays produced with "1"0"7Ag(#alpha#,n#gamma#)-"1"1"0In, "1"0"8Pd("6Li,4n#gamma#)"1"1"0In, "1"0"9Ag(#alpha#,n#gamma#)"1"1"2In and "1"1"0Pd("6Li,4n#gamma#)"1"1"2In reactions. In addition, the "1"1"4In energy level structure was investigated with the "1"1"0Pd("7Li,3n#gamma#)"1"1"4In reaction. Properties of de-excitation #gamma#-rays were determined from #gamma#-#gamma# coincidence, excitation, and angular distribution measurements conducted with Ge(Li) and Ge(intr.) #gamma#-ray detectors. A sequence of intraconnected levels in each of "1"1"0,"1"1"2,"1"1"4In were assigned to the (#pi#g"-"1/sub 9/2/, #nu#h/sub 11/2/) configuration. For the "1"1"0,"1"1"2,"1"1"4In energy level schemes a model calculation has ...

CERN Document Server

In a recent paper by Hooper and Goodenough, data from the Fermi Gamma Ray Telescope was analyzed and an excess of gamma rays was found in the emission spectrum from the Galactic Center Region. Hooper and Goodenough show that the excess can be well explained by 7-10 GeV annihilating dark matter with a power law density profile if the dark matter annihilates predominantly to tau pairs. In this paper we present such a dark matter model by extending the MSSM to include four Higgs doublets and one scalar singlet. A Z2 symmetry is imposed that enforces a Yukawa structure so that the up quarks, down quarks, and leptons each receive mass from a distinct doublet. This leads to an enhanced coupling of scalars to leptons and allows the model to naturally achieve the required phenomenology in order to explain the gamma ray excess. Our model yields the correct dark matter ...

International Nuclear Information System (INIS)

Bulgarian ... Orig. Title Vliyanie na gama-lychite vyrkhu spirokheti ot vida Borrelia anserina, Sakharoff, 1891. Chast 2. Promeni v antigenniya stroezh.

International Nuclear Information System (INIS)

Pregnant rats in 11d and 16d of their pregnancy were given one-off whole body exposure by "1"3"7Cs #gamma# rays to 0.2, 0.4, 0.9 and 2.0 Gy, respectively. Changes were observed in conditioned drinking response and cerebrum hippocampi cone cell number of the baby rats exposed to the #gamma# rays in different periods of their embryo development. As a result, that pregnant rats exposed to "1"3"7Cs #gamma# rays in different pregnant periods may induce significant decrease in cerebrum hippocampi cone cell number and achieving rate of conditioned drinking response of the babies. The dose-response relationship can be described by Y=a-b log_1_0D. The achieving rate of conditioned drinking response were significantly correlated to cerebrum hippocampi cone cell number in the babies, and the achieving rate of conditioned drinking response of the babies exposed at pregnant ...

Science.gov (United States)

Probing Neutron Star Evolution with Gamma Rays Online Source: Click to View PDF File [PDF Size: 217 KB] Author: Wijers, Ralph A. M. J. ...