Characteristics of environmental gamma-rays and dose assessment

International Nuclear Information System (INIS)

Saito, Kimiaki; Moriuchi, Shigeru

1986-01-01

Environmental radioactivity has attracted much attention in terms of exposure to the population, although its exposure doses are minimal. This paper presents problems encountered in the assessment of exposure doses using model and monitoring systems, focusing on the characteristics, such as energy distribution, direction distribution, and site, of environmental gamma-rays. The assessment of outdoor and indoor exposure doses of natural gamma-rays is discussed in relation to the shielding effect of the human body. In the assessment of artificial gamma-rays, calculation of exposure doses using build-up factor, the shielding effect of the human body, and energy dependency of the measuring instrument are covered. A continuing elucidation about uncertainties in dose assessment is emphasized. (Namekawa, K.)

Biological dose estimation for accidental supra-high dose gamma-ray exposure

International Nuclear Information System (INIS)

Chen, Y.; Yan, X.K.; Du, J.; Wang, Z.D.; Zhang, X.Q.; Zeng, F.G.; Zhou, P.K.

2011-01-01

To correctly estimate the biological dose of victims accidentally exposed to a very high dose of 60 Co gamma-ray, a new dose-effect curve of chromosomal dicentrics/multicentrics and rings in the supra-high dose range was established. Peripheral blood from two healthy men was irradiated in vitro with doses of 60 Co gamma-rays ranging from 6 to 22 Gy at a dose rate of 2.0 Gy/min. Lymphocytes were concentrated, cultured and harvested at 52 h, 68 h and 72 h. The numbers of dic + r were counted. The dose-effect curves were established and validated using comparisons with doses from the Tokai-mura accident and were then applied to two victims of supra-high dose exposure accident. The results indicated that there were no significant differences in chromosome aberration frequency among the different culture times from 52 h to 72 h. The 6-22 Gy dose-effect curve was fitted to a linear quadratic model Y = -2.269 + 0.776D - 7.868 x l0 -3 D 2 . Using this mathematic model, the dose estimates were similar to data from Tokai-mura which were estimated by PCC ring. Whole body average doses of 9.7 Gy and 18.1 Gy for two victims in the Jining accident were satisfactorily given. We established and successfully applied a new dose-effect curve of chromosomal dicentrics plus ring (dic + r) after 6-22 Gy γ-irradiation from a supra-high dose 60 Co gamma-ray accident.

Cellular response to low Gamma-ray doses

Energy Technology Data Exchange (ETDEWEB)

Manzanares A, E; Vega C, H R; Leon, L.C. de . [Unidades Academicas de Estudios Nucleares, Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico); Rebolledo D, O; Radillo J, F [Facultad de Ciencias Biologicas y Agropecuarias de la Universidad de Colima, Colima (Mexico)

2002-07-01

Lymphocytes, obtained from healthy donors, were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp70 and Hsc70.Hsp70 protein was detected after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 1.25 c Gy gamma-ray dose, lymphocytes expressed Hsp70 protein, indicating a threshold response to gamma rays. (Author)

Cellular response to low Gamma-ray doses

International Nuclear Information System (INIS)

Manzanares A, E.; Vega C, H.R.; Leon, L.C. de; Rebolledo D, O.; Radillo J, F.

2002-01-01

Lymphocytes, obtained from healthy donors, were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp70 and Hsc70.Hsp70 protein was detected after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 1.25 c Gy gamma-ray dose, lymphocytes expressed Hsp70 protein, indicating a threshold response to gamma rays. (Author)

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

Science.gov (United States)

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

2017-04-01

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

Terrestrial gamma dose rate in Pahang state Malaysia

International Nuclear Information System (INIS)

Gabdo, H.T.; Federal College of Education, Yola; Ramli, A.T.; Sanusi, M.S.; Saleh, M.A.; Garba, N.N.; Ahmadu Bello University, Zaria

2014-01-01

Environmental terrestrial gamma radiations (TGR) were measured in Pahang state Malaysia between January and April 2013. The TGR dose rates ranged from 26 to 750 nGy h -1 . The measurements were done based on geology and soil types of the area. The mean TGR dose rate was found to be 176 ± 5 nGy h -1 . Few areas of relatively enhanced activity were located in Raub, Temerloh, Bentong and Rompin districts. These areas have external gamma dose rates of between 500 and 750 nGy h -1 . An Isodose map of the state was produced using ArcGIS9 software version 9.3. To evaluate the radiological hazard due to terrestrial gamma dose, the annual effective dose equivalent and the mean population weighted dose rate were calculated and found to be 0.22 mSv year -1 and 168 nGy h -1 respectively. (author)

Dose Rate of Environmental Gamma Radiation in Java Island

International Nuclear Information System (INIS)

Gatot Suhariyono; Buchori; Dadong Iskandar

2007-01-01

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

Studying and measuring the gamma radiation doses in Homs city

International Nuclear Information System (INIS)

Sofaan, A. H.

2001-01-01

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

Evaluation of dose distributions in gamma chamber using glass plate detector

Directory of Open Access Journals (Sweden)

Narayan Pradeep

2008-01-01

Full Text Available A commercial glass plate of thickness 1.75 mm has been utilized for evaluation of dose distributions inside the irradiation volume of gamma chamber using optical densitometry technique. The glass plate showed linear response in the dose range 0.10 Kilo Gray (kGy to 10 kGy of cobalt-60 gamma radiation with optical sensitivity 0.04 Optical Density (OD /kGy. The change in the optical density at each identified spatial dose matrix on the glass plate in relation to the position in the irradiation volume has been presented as dose distributions inside the gamma chamber. The optical density changes have been graphically plotted in the form of surface diagram of color washes for different percentage dose rate levels as isodose distributions in gamma chamber. The variation in dose distribution inside the gamma chamber unit, GC 900, BRIT India make, using this technique has been observed within ± 15%. This technique can be used for routine quality assurances and dose distribution validation of any gamma chamber during commissioning and source replacement. The application of commercial glass plate for dose mapping in gamma chambers has been found very promising due to its wider dose linearity, quick measurement, and lesser expertise requirement in application of the technique.

beta. and. gamma. -comparative dose estimates on Enewetak Atoll

Energy Technology Data Exchange (ETDEWEB)

Crase, K.W.; Gudiksen, P.H.; Robison, W.L. (California Univ., Livermore (USA). Lawrence Livermore National Lab.)

1982-05-01

Enewetak Atoll in the Pacific is used for atmospheric testing of U.S. nuclear weapons. Beta dose and ..gamma..-ray exposure measurements were made on two islands of the Enewetak Atoll during July-August 1976 to determine the ..beta.. and low energy ..gamma..-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a ..beta..-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to ..beta..- or low energy ..gamma..-contribution. The contribution at any particular site, however, is reduced by vegetation. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey. Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the ..beta..'s or low energy ..gamma..'s, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

Gamma dosimetry of high doses

International Nuclear Information System (INIS)

Martinez C, T.; Galvan G, A.; Canizal, G.

1991-01-01

The gamma dosimetry of high doses is problematic in almost all the classic dosemeters either based on the thermoluminescence, electric, chemical properties, etc., because they are saturated to very high dose and they are no longer useful. This work carries out an investigation in the interval of high doses. The solid system of heptahydrate ferrous sulfate, can be used as solid dosemeter of routine for high doses of radiation. The proposed method is simple, cheap and it doesn't require sophisticated spectrophotometers or spectrometers but expensive and not common in some laboratories

Mapping the outdoor gamma dose rate in Indonesia

International Nuclear Information System (INIS)

Iskandar, Dadong; Syarbaini, Sutarman; Bunawas, Kusdiana

2008-01-01

Full text: Indonesia is the largest archipelago in the world, comprising five main islands - Java, Sumatra, Sulawesi, Kalimantan and Papua - as well as 30 archipelagoes totaling 17,508 islands with about 6000 of those inhabited. Mapping the outdoor gamma dose rate in Indonesia is a research project conducted by National Nuclear Energy Agency since 2005 aiming to produce a baseline data map as an overview for planning purposes. In these three years 4 main islands has been measured. The grid system has been used in the research. In Sumatra Island the grid is 50 x 50 km 2 , while in Java 40 x 40 km 2 , in Kalimantan 60 x 60 km 2 , and in Sulawesi 40 x 40 km 2 . The gamma dose rates have been measured by Mini Gamma Ray Spectrometer Model GR-130 made by Exploranium-Canada. Figure 1 shows the map of outdoor gamma dose rate in Indonesia. Range of dose rate are in Sumatra from 22,96 ± 0,46 n Sv/h to 186,08 ± 3,72 n Sv/h, in Java 11,32 ± 0,72 n Sv/h to 127,54 ± 6,14 n Sv/h, in Kalimantan 10.72 ± 8.32 n Sv/h to 349,48 ± 57,21 n Sv/h, and in Sulawesi 17.7 ± 11,5 n Sv/h to 467 ± 102 n Sv/h. The arithmetic and geometric mean of dose rate in Indonesia are 68 n Sv/h and 53 n Sv/h, respectively. In general, outdoor gamma dose rate in Indonesia is in a normal range. There are some regions have anomaly of gamma dose rate, for examples at North Sumatra 186.08 ± 3,72 n Sv/h (N 2.12727, E 99.80909), at West Kalimantan 349,48 ± 57,21 n Sv/h (S 1.39507, E 110.57584), at West Sulawesi 487 ± 103 n Sv/h (S 2.95781, E 118.86995), etc. These data is very useful as a radiation baseline in Indonesia. (author)

Inactive Doses and Protein Concentration of Gamma Irradiated Yersinia Enterocolitica

International Nuclear Information System (INIS)

Irawan Sugoro; Sandra Hermanto

2009-01-01

Yersinia enterocolitica is one of bacteria which cause coliform mastitis in dairy cows. The bacteria could be inactivated by gamma irradiation as inactivated vaccine candidate. The experiment has been conducted to determine the inactive doses and the protein concentration of Yersinia enterocolitica Y3 which has been irradiated by gamma rays. The cells cultures were irradiated by gamma rays with doses of 0, 100, 200, 400, 600, 800, 1.000 and 1.500 Gy (doses rate was 1089,59 Gy/hours). The inactive dose was determined by the drop test method and the protein concentration of cells were determined by Lowry method. The results showed that the inactive doses occurred on 800 – 1500 Gy. The different irradiation doses of cell cultures showed the effect of gamma irradiation on the protein concentration that was random and has a significant effect on the protein concentration. (author)

Population doses from terrestrial gamma exposure in China

International Nuclear Information System (INIS)

Ren, T.; Wang, Z.; Zhu, C.

1992-01-01

In order to estimate terrestrial gamma radiation exposure three nationwide surveys have been completed since 1981. The population-weighted outdoor and indoor arithmetic means of gamma dose rate based on momentary dose rate measurements using a NaI(Tl) environmental radiation meter and high-pressure ionisation chamber are, respectively, 80.3 nGy.h -1 and 120 nGy.h -1 . Based on integrating dose measurement using TLD CaSO 4 /Dy they are 67 nGy.h -1 and 89 nGy.h -1 respectively, and based on natural radionuclides concentrations in soil, determined by gamma spectroscopy analyses, they are 72.8 nGy.h -1 and 102 nGy.h -1 , respectively. These surveys were conducted independently by different groups. The best estimations of population-weighted gamma dose rates in China, based on all these surveys, would be 70 nGy.h -1 and 98 nGy.h -1 for outdoors and indoors, respectively. The annual average of effective dose equivalent is 0.56 mSv. These values are higher than the world averages estimated by UNSCEAR. The main reason is that the concentrations of 232 Th and 40 K in the soil of China are much higher than the world average estimated. (author)

Calculation method for gamma dose rates from Gaussian puffs

Energy Technology Data Exchange (ETDEWEB)

Thykier-Nielsen, S; Deme, S; Lang, E

1995-06-01

The Lagrangian puff models are widely used for calculation of the dispersion of releases to the atmosphere. Basic output from such models is concentration of material in the air and on the ground. The most simple method for calculation of the gamma dose from the concentration of airborne activity is based on the semi-infinite cloud model. This method is however only applicable for puffs with large dispersion parameters, i.e. for receptors far away from the release point. The exact calculation of the cloud dose using volume integral requires large computer time usually exceeding what is available for real time calculations. The volume integral for gamma doses could be approximated by using the semi-infinite cloud model combined with correction factors. This type of calculation procedure is very fast, but usually the accuracy is poor because only a few of the relevant parameters are considered. A multi-parameter method for calculation of gamma doses is described here. This method uses precalculated values of the gamma dose rates as a function of E{sub {gamma}}, {sigma}{sub y}, the asymmetry factor - {sigma}{sub y}/{sigma}{sub z}, the height of puff center - H and the distance from puff center R{sub xy}. To accelerate the calculations the release energy, for each significant radionuclide in each energy group, has been calculated and tabulated. Based on the precalculated values and suitable interpolation procedure the calculation of gamma doses needs only short computing time and it is almost independent of the number of radionuclides considered. (au) 2 tabs., 15 ills., 12 refs.

Measurement of gamma radiation doses in nuclear power plant environment

International Nuclear Information System (INIS)

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

1976-01-01

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

Cellular Stress to Low Gamma-ray Dose

International Nuclear Information System (INIS)

Manzanares-Acuna, E.; Vega-Carrillo, H. R.; Letechipia de Leon, C.; Guzman Enriquez, L. J.; Garcia-Talavera, M.

2004-01-01

The purpose of this study was to evaluate the effect of low gamma ray intensity upon Hsp 70 expression in human lymphocytes. the heat shock proteins (Hsp) family, are a group of proteins present in all living organism, therefore there are highly conserved and are related to adaptation and evolution. At cellular level these proteins acts as chaperones correcting denatured proteins. when a stress agent, such heavy metals, UV, heat, etc. is affecting a cell a response to this aggression is triggered through overexpression of Hsp. Several studies has been carried out in which the cellular effect are observed, mostly of these studies uses large doses, but very few studies are related with low doses. Blood of healthy volunteers was obtained and the lymphocytes were isolated by ficoll-histopaque gradient. Experimental lots were irradiated in a ''137Cs gamma-ray. Hsp70 expression was found since 0.5 cGy, indicating a threshold to very low doses of gamma rays. (Author) 27 refs

beta- and gamma-Comparative dose estimates on Eniwetok Atoll

Energy Technology Data Exchange (ETDEWEB)

Crase, K.W.; Gudiksen, P.H.; Robison, W.L.

1982-05-01

Eniwetok Atoll is one of the Pacific atolls used for atmospheric testing of U.S. nuclear weapons. Beta dose and gamma-ray exposure measurements were made on two islands of the Eniwetok Atoll during July-August 1976 to determine the beta and low energy gamma-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a beta-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to beta- or low energy gamma-contribution. The contribution at any particular site, however, is somewhat dependent on ground cover, since a minimal amount of vegetation will reduce it significantly from that over bare soil, but thick stands of vegetation have little effect on any further reductions. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey (En73). Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the beta's or low energy gamma's, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

Population doses from terrestrial gamma exposure in China

Energy Technology Data Exchange (ETDEWEB)

Ren, T.; Wang, Z.; Zhu, C. (Ministry of Public Health, Beijing, BJ (China))

1992-01-01

In order to estimate terrestrial gamma radiation exposure three nationwide surveys have been completed since 1981. The population-weighted outdoor and indoor arithmetic means of gamma dose rate based on momentary dose rate measurements using a NaI(Tl) environmental radiation meter and high-pressure ionisation chamber are, respectively, 80.3 nGy.h[sup -1] and 120 nGy.h[sup -1]. Based on integrating dose measurement using TLD CaSO[sub 4]/Dy they are 67 nGy.h[sup -1] and 89 nGy.h[sup -1] respectively, and based on natural radionuclides concentrations in soil, determined by gamma spectroscopy analyses, they are 72.8 nGy.h[sup -1] and 102 nGy.h[sup -1], respectively. These surveys were conducted independently by different groups. The best estimations of population-weighted gamma dose rates in China, based on all these surveys, would be 70 nGy.h[sup -1] and 98 nGy.h[sup -1] for outdoors and indoors, respectively. The annual average of effective dose equivalent is 0.56 mSv. These values are higher than the world averages estimated by UNSCEAR. The main reason is that the concentrations of [sup 232]Th and [sup 40]K in the soil of China are much higher than the world average estimated. (author).

Novel Radiobiological Gamma Index for Evaluation of 3-Dimensional Predicted Dose Distribution

Energy Technology Data Exchange (ETDEWEB)

Sumida, Iori, E-mail: sumida@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Yamaguchi, Hajime; Kizaki, Hisao; Aboshi, Keiko; Tsujii, Mari; Yoshikawa, Nobuhiko; Yamada, Yuji [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Suzuki, Osamu; Seo, Yuji [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Isohashi, Fumiaki [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Yoshioka, Yasuo [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan)

2015-07-15

Purpose: To propose a gamma index-based dose evaluation index that integrates the radiobiological parameters of tumor control (TCP) and normal tissue complication probabilities (NTCP). Methods and Materials: Fifteen prostate and head and neck (H&N) cancer patients received intensity modulated radiation therapy. Before treatment, patient-specific quality assurance was conducted via beam-by-beam analysis, and beam-specific dose error distributions were generated. The predicted 3-dimensional (3D) dose distribution was calculated by back-projection of relative dose error distribution per beam. A 3D gamma analysis of different organs (prostate: clinical [CTV] and planned target volumes [PTV], rectum, bladder, femoral heads; H&N: gross tumor volume [GTV], CTV, spinal cord, brain stem, both parotids) was performed using predicted and planned dose distributions under 2%/2 mm tolerance and physical gamma passing rate was calculated. TCP and NTCP values were calculated for voxels with physical gamma indices (PGI) >1. We propose a new radiobiological gamma index (RGI) to quantify the radiobiological effects of TCP and NTCP and calculate radiobiological gamma passing rates. Results: The mean RGI gamma passing rates for prostate cases were significantly different compared with those of PGI (P<.03–.001). The mean RGI gamma passing rates for H&N cases (except for GTV) were significantly different compared with those of PGI (P<.001). Differences in gamma passing rates between PGI and RGI were due to dose differences between the planned and predicted dose distributions. Radiobiological gamma distribution was visualized to identify areas where the dose was radiobiologically important. Conclusions: RGI was proposed to integrate radiobiological effects into PGI. This index would assist physicians and medical physicists not only in physical evaluations of treatment delivery accuracy, but also in clinical evaluations of predicted dose distribution.

Population doses from terrestrial gamma exposure in China

International Nuclear Information System (INIS)

Ren, T.; Wang, Z.; Zhu, C.

1993-01-01

In order to estimate terrestrial gamma radiation exposures, three nationwide surveys have been completed since 1981. The population weighted outdoor and indoor arithmetic means of gamma dose rates based on momentary measurements using a NaI(T1) environmental radiation meter and a high pressured ionization chamber are 80.3 and 120 nGy.h -1 . The means based on integrating measurements using TLD natural radionuclides concentrations in soil, determined by gamma spectrometry analyses, are 72.8 and 102 nGy.h -1 , respectively. These surveys were conducted independently and equally representative. The best estimation of site-averaged and population weighted gamma dose rates in China, based on all these surveys, would be 70 and 98 nGy.h -1 for indoor and outdoor, respectively. The annual average of effective dose equivalent is 0.56 mSv. These values are higher than the world averages estimated by UNSCEAR. The main reason is that the concentrations of 232 Th and 40 K in soil of China are much higher than the world average estimated. (author). 4 refs, 2 tabs

Dose-dependent hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to sublethal doses of gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Song, You, E-mail: you.song@niva.no [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway); Salbu, Brit; Teien, Hans-Christian; Heier, Lene Sørlie [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Rosseland, Bjørn Olav [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian University of Life Sciences (NMBU), Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 Ås (Norway); Tollefsen, Knut Erik [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway)

2014-11-15

Highlights: • First study on early stress responses in salmon exposed to low-dose gamma radiation. • Dramatic dose-dependent transcriptional responses characterized. • Multiple modes of action proposed for gamma radiation. - Abstract: Due to the production of free radicals, gamma radiation may pose a hazard to living organisms. The high-dose radiation effects have been extensively studied, whereas the ecotoxicity data on low-dose gamma radiation is still limited. The present study was therefore performed using Atlantic salmon (Salmo salar) to characterize effects of low-dose (15, 70 and 280 mGy) gamma radiation after short-term (48 h) exposure. Global transcriptional changes were studied using a combination of high-density oligonucleotide microarrays and quantitative real-time reverse transcription polymerase chain reaction (qPCR). Differentially expressed genes (DEGs; in this article the phrase gene expression is taken as a synonym of gene transcription, although it is acknowledged that gene expression can also be regulated, e.g., at protein stability and translational level) were determined and linked to their biological meanings predicted using both Gene Ontology (GO) and mammalian ortholog-based functional analyses. The plasma glucose level was also measured as a general stress biomarker at the organism level. Results from the microarray analysis revealed a dose-dependent pattern of global transcriptional responses, with 222, 495 and 909 DEGs regulated by 15, 70 and 280 mGy gamma radiation, respectively. Among these DEGs, only 34 were commonly regulated by all radiation doses, whereas the majority of differences were dose-specific. No GO functions were identified at low or medium doses, but repression of DEGs associated with GO functions such as DNA replication, cell cycle regulation and response to reactive oxygen species (ROS) were observed after 280 mGy gamma exposure. Ortholog-based toxicity pathway analysis further showed that 15 mGy radiation

Calculation method for gamma dose rates from Gaussian puffs

International Nuclear Information System (INIS)

Thykier-Nielsen, S.; Deme, S.; Lang, E.

1995-06-01

The Lagrangian puff models are widely used for calculation of the dispersion of releases to the atmosphere. Basic output from such models is concentration of material in the air and on the ground. The most simple method for calculation of the gamma dose from the concentration of airborne activity is based on the semi-infinite cloud model. This method is however only applicable for puffs with large dispersion parameters, i.e. for receptors far away from the release point. The exact calculation of the cloud dose using volume integral requires large computer time usually exceeding what is available for real time calculations. The volume integral for gamma doses could be approximated by using the semi-infinite cloud model combined with correction factors. This type of calculation procedure is very fast, but usually the accuracy is poor because only a few of the relevant parameters are considered. A multi-parameter method for calculation of gamma doses is described here. This method uses precalculated values of the gamma dose rates as a function of E γ , σ y , the asymmetry factor - σ y /σ z , the height of puff center - H and the distance from puff center R xy . To accelerate the calculations the release energy, for each significant radionuclide in each energy group, has been calculated and tabulated. Based on the precalculated values and suitable interpolation procedure the calculation of gamma doses needs only short computing time and it is almost independent of the number of radionuclides considered. (au) 2 tabs., 15 ills., 12 refs

In situ measurements of dose rates from terrestrial gamma rays

International Nuclear Information System (INIS)

Horng, M.C.; Jiang, S.H.

2002-01-01

A portable, high purity germanium (HPGe) detector was employed for the performance of in situ measurements of radionuclide activity concentrations in the ground in Taiwan, at altitudes ranging from sea level to 3900 m. The absolute peak efficiency of the HPGe detector for a gamma-ray source uniformly distributed in the semi-infinite ground was determined using a semi-empirical method. The gamma-ray dose rates from terrestrial radionuclides were calculated from the measured activity levels using recently published dose rate conversion factors. The absorbed dose rate in air due to cosmic rays was derived by subtracting the terrestrial gamma-ray dose rate from the overall absorbed dose rate in air measured using a high-pressure ionization chamber. The cosmic-ray dose rate calculated as a function of altitude, was found to be in good agreement with the data reported by UNSCEAR. (orig.)

Spectroscopic gamma camera for use in high dose environments

Energy Technology Data Exchange (ETDEWEB)

Ueno, Yuichiro, E-mail: yuichiro.ueno.bv@hitachi.com [Research and Development Group, Hitachi, Ltd., Hitachi-shi, Ibaraki-ken 319-1221 (Japan); Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi [Research and Development Group, Hitachi, Ltd., Hitachi-shi, Ibaraki-ken 319-1221 (Japan); Fujishima, Yasutake; Kometani, Yutaka [Hitachi Works, Hitachi-GE Nuclear Energy, Ltd., Hitachi-shi, Ibaraki-ken (Japan); Suzuki, Yasuhiko [Measuring Systems Engineering Dept., Hitachi Aloka Medical, Ltd., Ome-shi, Tokyo (Japan); Umegaki, Kikuo [Faculty of Engineering, Hokkaido University, Sapporo-shi, Hokkaido (Japan)

2016-06-21

We developed a pinhole gamma camera to measure distributions of radioactive material contaminants and to identify radionuclides in extraordinarily high dose regions (1000 mSv/h). The developed gamma camera is characterized by: (1) tolerance for high dose rate environments; (2) high spatial and spectral resolution for identifying unknown contaminating sources; and (3) good usability for being carried on a robot and remotely controlled. These are achieved by using a compact pixelated detector module with CdTe semiconductors, efficient shielding, and a fine resolution pinhole collimator. The gamma camera weighs less than 100 kg, and its field of view is an 8 m square in the case of a distance of 10 m and its image is divided into 256 (16×16) pixels. From the laboratory test, we found the energy resolution at the 662 keV photopeak was 2.3% FWHM, which is enough to identify the radionuclides. We found that the count rate per background dose rate was 220 cps h/mSv and the maximum count rate was 300 kcps, so the maximum dose rate of the environment where the gamma camera can be operated was calculated as 1400 mSv/h. We investigated the reactor building of Unit 1 at the Fukushima Dai-ichi Nuclear Power Plant using the gamma camera and could identify the unknown contaminating source in the dose rate environment that was as high as 659 mSv/h.

Contributions to indoor gamma dose rate from building materials

International Nuclear Information System (INIS)

Liu Xionghua; Li Guangming; Yang Xiangdong

1990-01-01

In the coures of construction of a building structured with bricks and concrets, the indoor gamma air absorbed dose rates were seperately measured from the floors, brick walls and prefabricated plates of concrets, etc.. It suggested that the indoor gamma dose rates from building materials are mainly attributed to the brick walls and the floors. A little contribution comes from other brilding materials. The dose rates can be calculated through a 4π-infinite thick model with a correction factor of 0.52

Response of human lymphocytes to low gamma ray doses

International Nuclear Information System (INIS)

Vega Carrillo, HR; Banuelos Valenzuela, R; Manzanares Acuna, E; Sanchez-Rodriguez, S.H

2001-01-01

Radiation and non-radiation workers lymphocytes were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp25, Hsp60, Hsp70 and Hsp90; from these, only Hsp70 protein was detected before and after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 70.5 mGy gamma-ray dose, radiation worker's lymphocytes expressed more Hsp70 protein, than non-radiation workers' lymphocytes, indicating a larger tolerance to gamma rays (gamma tolerance), due to an adaptation process developed by their labor condition (Au)

Development of air equivalent gamma dose monitor

International Nuclear Information System (INIS)

Alex, Mary; Bhattacharya, Sadhana; Karpagam, R.; Prasad, D.N.; Jakati, R.K.; Mukhopadhyay, P.K.; Patil, R.K.

2010-01-01

The paper describes design and development of air equivalent gamma absorbed dose monitor. The monitor has gamma sensitivity of 84 pA/R/h for 60 Co source. The characterization of the monitor has been done to get energy dependence on gamma sensitivity and response to gamma radiation field from 1 R/hr to 5000 R/hr. The gamma sensitivity in the energy range of 0.06 to 1.25MeV relative to 137 Cs nuclide was within 2.5%. The linearity of the monitor response as a function of gamma field from 10 R/h to 3.8 kR/h was within 6%. The monitor has been designed for its application in harsh environment. It has been successfully qualified to meet environmental requirements of shock. (author)

Dose mapping role in gamma irradiation industry

International Nuclear Information System (INIS)

Noriah Mod Ali; John Konsoh Sangau; Mazni Abd Latif

2002-01-01

In this studies, the role of dosimetry activity in gamma irradiator was discussed. Dose distribution in the irradiator, which is a main needs in irradiator or chamber commissioning. This distribution data were used to confirm the dosimetry parameters i.e. exposure time, maximum and minimum dose map/points, and dose distribution - in which were used as guidelines for optimum product irradiation. (Author)

Thyroid doses from external gamma-exposure following the Chernobyl accident

International Nuclear Information System (INIS)

Tretyakevich, Sergey; Kukhta, Tatyana; Minenko, Victor; Drozdovitch, Vladimir; Luckyanov, Nickolas; Gavrilin, Yury; Khrouch, Valeri; Shinkarev, Sergey

2008-01-01

Full text: An increase of thyroid cancer incidence among children in Belarus has been observed after the Chernobyl accident. The main contributor to the thyroid dose was caused by 131 I intake with fresh milk in 1986. Other contributions to the thyroid dose (external gamma-exposure, short-lived iodine isotopes, internal radiocesium) were small in comparison to the dose from 131 I intakes soon after the accident. However, exposures to external radiation continued for a number of years after the accident. Thyroid doses from external gamma-exposure following the Chernobyl accident were mainly caused by gamma-exposure to 24 nuclides: 95 Zr, 95 Nb, 99 Mo, 99 mTc, 103 Ru, 103m Rh, 106 Ru, 125 Sb, 125m Te, 131m Te, 131 I, 132 Te, 132 I, 133 I, 135 I, 134 Cs, 136 Cs, 137 Cs, 140 Ba, 140 La, 141 Ce, 144 Ce, 144 Pr, 239 Np. Data of personal interview were used to take into account the personal residence history for the time elapsed from the Chernobyl accident until the interview (10 to 15 years later). Cumulative thyroid doses caused by external gamma-exposure during the passage of the radioactive cloud and from the ground contamination following the Chernobyl accident have been reconstructed. The median thyroid dose from external gamma-exposure to ∼11,770 cohort members of an epidemiological study was estimated to be ∼6 mGy. There are ∼3,400 persons with external dose estimates that exceed 20 mGy. Exposure from radionuclides deposited on the ground was the main source of external dose. The contribution from the passing radioactive cloud to external dose was found to be negligible. (author)

Study on dose distribution of therapeutic proton beams with prompt gamma measurement

Energy Technology Data Exchange (ETDEWEB)

Kim, J. W. [National Cancer Center, Seoul (Korea, Republic of); Min, C. H.; Kim, C. H.; Kim, D. K.; Yoon, M. Y. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2007-03-15

The proton beam has an advantage of the sharp dose falloff in dose distribution called Bragg peak while conventional radiation therapy modalities such as photons exhibit considerable amount of exit dose. To take advantage of this property it is important to know the exact location of the distal dose falloff. An error can cause overdose to the normal tissue or underdose to the tumor volume. The only way of finding out the dose distribution in-situ in particle therapy is to measure the gammas produced by nuclear reactions with tissue materials. Two kinds of gammas can be used: one is prompt gamma and the other is coincident gamma from the positron-emission isotopes. We chose to detect prompt gammas, and developed a prompt gamma scanning system (PGS). The proton beams of the proton therapy facility at National Cancer Center were used. The gamma distribution was compared to the dose distribution measured by an ionization chamber at three different energies of 100, 150, 200 MeV's. The two distributions were well correlated within 1-2 mm. The effect of high-energy neutron appeared as blurred distribution near the distal dose falloff at the energy of 200 MeV. We then tested the PGS shielding design by adding additional layer of paraffin plates outside of the PGS, and found that fast neutrons significantly affect the background level. But the location of the dose fall-off was nearly coincident. The analysis of gamma energy spectrum showed that cut-off energy in gamma counting can be adjusted to enhance the signal to noise ratio. Further the ATOM phantom, which has similar tissue structure to human, was used to investigate the gamma distribution for the case of inhomogeneous matter. The location of dose falloff region was found to be well defined as for water phantom. Next an actual therapy beam, which was produced by the double scattering method, was used, for which the dose falloff by the gamma distribution was completely wiped out by background neutrons. It is not

Calculation method for gamma-dose rates from spherical puffs

International Nuclear Information System (INIS)

Thykier-Nielsen, S.; Deme, S.; Lang, E.

1993-05-01

The Lagrangian puff-models are widely used for calculation of the dispersion of atmospheric releases. Basic output from such models are concentrations of material in the air and on the ground. The most simple method for calculation of the gamma dose from the concentration of airborne activity is based on semi-infinite cloud model. This method is however only applicable for points far away from the release point. The exact calculation of the cloud dose using the volume integral requires significant computer time. The volume integral for the gamma dose could be approximated by using the semi-infinite cloud model combined with correction factors. This type of calculation procedure is very fast, but usually the accuracy is poor due to the fact that the same correction factors are used for all isotopes. The authors describe a more elaborate correction method. This method uses precalculated values of the gamma-dose rate as a function of the puff dispersion parameter (δ p ) and the distance from the puff centre for four energy groups. The release of energy for each radionuclide in each energy group has been calculated and tabulated. Based on these tables and a suitable interpolation procedure the calculation of gamma doses takes very short time and is almost independent of the number of radionuclides. (au) (7 tabs., 7 ills., 12 refs.)

Dose-response of photographic emulsions under gamma irradiation

International Nuclear Information System (INIS)

Tran Dai Nghiep; Do Thi Nguyet Minh; Le Van Vinh

2003-01-01

Photographic emulsion is irradiated under gamma rays irradiation of 137 Cs in the IAEA/WHO secondary standard dosimetry laboratory. Dose-response of the film is established. The sensitivity of the film is determined. The dose-rate effect is studied. (author)

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

International Nuclear Information System (INIS)

Prokic, M.

1974-01-01

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

Gamma ray doses proceeding from natural occurring radionuclides in closed environments

International Nuclear Information System (INIS)

Aguiar, Vitor Angelo P. de; Medina, Nilberto H.; Silveira, Marcilei A. Guazzelli da; Moreira, Ramon H.

2009-01-01

In this work we report on the application of gamma-ray spectrometry in the study of the effective dose coming from terrestrial natural elements present in building materials such as sand, cement, lime (CaO) and milled granitic stones. The major contribution to annual gamma-ray radiation effective dose is due to the natural occurring radionuclides 40 K, 232 Th and 238 U. Two spectrometry systems were employed to measure the gamma radiation: one with a 60% efficient GeHP detector and the second one with a 2''x2'' NaI(Tl) scintillator. The estimated effective dose coming from the three reference rooms assumed is 0.63 mSv/yr, proceeding from terrestrial natural elements. The principal gamma radiation sources are cement, sand and bricks. (author)

High gamma dose response of the electrical properties of polyethylene terephthalate thin films

International Nuclear Information System (INIS)

Radwan, R.M.

2007-01-01

Electrical properties of polyethylene terephthalate (PET), irradiated with gamma rays, have been investigated. The PET films were irradiated with high gamma dose levels in the range from 100 to 2000 kGy. The changes in the DC (σ DC ) and the ac (σ ac ) conductivities, with the dose, have been performed. The effect of gamma irradiation on the dielectric constant (ε') and loss (ε'') has been determined. Also, the dose dependence of the frequency exponent index (S), the resonance frequency (Fc) and the hopping frequency (ω P ) have been obtained. The obtained results show that increasing gamma dose leads to slight increase in σ DC , σ ac and ε', while no change was observed in ε'' value. Meanwhile, S, Fc and ω P are inversely proportional to the dose. Accordingly, the study suggests the possibility of using PET films in electronic components (capacitors, resistors, etc.), especially that operate at high gamma dose environments for the frequency independent applications

Car-borne survey of natural background gamma dose rate in Canakkale region (Turkey)

International Nuclear Information System (INIS)

Turhan, S.; Arikan, I. H.; Oquz, F.; Aezdemir, T.; Yuecel, B.; Varinlioqlu, A.; Koese, A.

2012-01-01

Natural background gamma radiation was measured along roads in the environs of Canakkale region by using a car-borne spectrometer system with a plastic gamma radiation detector. In addition, activity concentrations of 238 U, 226 Ra, 232 Th and 40 K in soil samples from the Canakkale region were determined by using a gamma spectrometer with an HPGe detector. A total of 92 856 data of the background gamma dose rate were collected for the Canakkale region. The background gamma dose rate of the Canakkale region was mapped using ArcGIS software, applying the geostatistical inverse distance-weighted method. The average and population-weighted average of the gamma dose are 55.4 and 40.6 nGy h -1 , respectively. The corresponding average annual effective dose to the public ranged from 26.6 to 96.8 μSv. (authors)

Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

International Nuclear Information System (INIS)

Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M.; Carrillo F, J.; Montero C, M. E.

2015-10-01

Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226 Ra, 232 Th, 40 K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h -1 . Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg -1 , of 226 Ra, 232 Th and 40 K, respectively. From the analysis of the spatial distribution of 232 Th, 226 Ra, and 40 K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

Dose Rate and Mass Attenuation Coefficients of Gamma Ray for Concretes

CERN Document Server

Abdel-Latif, A A; Kansouh, W A; El-Sayed, F H

2003-01-01

This work is concerned with the study of the leakage gamma ray dose and mass attenuation coefficients for ordinary, basalt and dolomite concretes made from local ores. Concretes under investigation were constructed from gravel, basalt and dolomite ores, and then reconstructed with the addition of 3% steel fibers by weight. Measurements were carried out using a collimated beam from sup 6 sup 0 Co gamma ray source and sodium iodide (3x3) crystal with the genie 2000 gamma spectrometer. The obtained fluxes were transformed to gamma ray doses and displayed in the form of gamma ray dose rates distribution. The displayed curves were used to estimate the linear attenuation coefficients (mu), the relaxation lengths (lambda), half value layer (t sub 1 /2) and tenth value layer (t sub 1 /10). Also, The total mass attenuation coefficients of gamma ray have been calculated to the concerned concretes using XCOM (version 3.1) program and database elements cross sections from Z=1 to 100 at energies from 10 keV to 100 MeV. In...

Measurements of gamma-ray dose from a moderated 252Cf source

International Nuclear Information System (INIS)

McDonald, J.C.; Griffith, R.V.; Plato, P.; Miklos, J.

1983-06-01

The gamma-ray dose fraction from a moderated 252 Cf source was determined by using three types of dosimetry systems. Measurements were carried out in air at a distance of 35 cm from the surface of the moderating sphere (50 cm from the source which is at the center of the sphere) to the geometrical center of each detector. The moderating sphere is 0.8-mm-thick stainless steel shell filled with D 2 O and covered with 0.5 mm of cadmium. Measurements were also carried out with instruments and dosimeters positioned at the surface of a 40 cm x 40 cm x 15 cm plexiglass irradiation phantom whose front surface was also 35 cm from the surface of the moderating sphere. A-150 tissue-equivalent (TE) plastic ionization chambers and a TE proportional counter (TEPC) were used to measure tissue dose, from which the neutron dose equivalent was computed. The ratio of gamma-ray dose to the neutron dose equivalent was determined by using a relatively neutron-insensitive Geiger-Mueller (GM) counter and thermoluminescent dosimeters (TLD). In addition, the event-size spectrum measured by the TEPC was also used to compute the gamma-ray dose fraction. The average value for the ratio of gamma-ray dose to neutron dose equivalent was found to be 0.18 with an uncertainty of about +-18%

Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

International Nuclear Information System (INIS)

Shamma, M.; Al-Adawi, M.; Sharabi, N.

2002-11-01

The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays. (author)

Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

CERN Document Server

Shamma, M A; Sharabi, N

2002-01-01

The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays.

Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

Energy Technology Data Exchange (ETDEWEB)

Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M. [Universidad Autonoma de Chihuahua, Facultad de Zootecnia y Ecologia, Perif. Francisco R. Almada Km 1, 31415 Chihuahua, Chih. (Mexico); Carrillo F, J.; Montero C, M. E., E-mail: mrenteria@uach.mx [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Chih. (Mexico)

2015-10-15

Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of {sup 226}Ra, {sup 232}Th, {sup 40}K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h{sup -1}. Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg{sup -1}, of {sup 226}Ra, {sup 232}Th and {sup 40}K, respectively. From the analysis of the spatial distribution of {sup 232}Th, {sup 226}Ra, and {sup 40}K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

Dose Rate Determination from Airborne Gamma-ray Spectra

DEFF Research Database (Denmark)

Bargholz, Kim

1996-01-01

The standard method for determination of ground level dose rates from airborne gamma-ray is the integral count rate which for a constant flying altitude is assumed proportional to the dose rate. The method gives reasonably results for natural radioactivity which almost always has the same energy...

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

International Nuclear Information System (INIS)

1985-01-01

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

The effect of gamma dose on the PADC detectors

International Nuclear Information System (INIS)

Zaky, M.F.; Youssef, A.A.

2002-01-01

The effect of irradiation by 6 0C O gamma rays in the range 0-60 K gray has been examined on CR-39 SSNTDs. The fission fragment tracks diameter were measured using an optical microscope, the bulk etching rate was calculated using the equation V B = D/2 t. The results indicate that, the track diameter is seen increase slowly in the range 0-60 K gray. The bulk etching rate increases almost linearly as the given gamma dose increases up to (22.5 K Gray), at higher doses the bulk etching rate increases exponentially. The exposure of the CR-39 to gamma rays could sensitize the CR-39 plastic and thus improve the Z/P threshold for track registration

The effect of Low-dose Gamma Radiation on the Bio-chemical ...

African Journals Online (AJOL)

Low-dose gamma radiation has been applied to intravenous fluids to enhance the sterility assurance levels. This study was undertaken to determine the stability of gamma irradiated 2.5 % dextrose, 2.5 % dextrose in saline, Ringers lactate and Gastrointestinal replacement fluid at doses of 0, 2, 4, 6, 8, 10 and 20 kGy.

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

Directory of Open Access Journals (Sweden)

Sergio Luevano-Gurrola

2015-09-01

Full Text Available Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.

Science.gov (United States)

Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

2015-09-30

Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

Science.gov (United States)

Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

2015-01-01

Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

Neutron and gamma dose and spectra measurements on the Little Boy replica

International Nuclear Information System (INIS)

Hoots, S.; Wadsworth, D.

1984-01-01

The radiation-measurement team of the Weapons Engineering Division at Lawrence Livermore National Laboratory (LLNL) measured neutron and gamma dose and spectra on the Little Boy replica at Los Alamos National Laboratory (LANL) in April 1983. This assembly is a replica of the gun-type atomic bomb exploded over Hiroshima in 1945. These measurements support the National Academy of Sciences Program to reassess the radiation doses due to atomic bomb explosions in Japan. Specifically, the following types of information were important: neutron spectra as a function of geometry, gamma to neutron dose ratios out to 1.5 km, and neutron attenuation in the atmosphere. We measured neutron and gamma dose/fission from close-in to a kilometer out, and neutron and gamma spectra at 90 and 30 0 close-in. This paper describes these measurements and the results. 12 references, 13 figures, 5 tables

Effect of low gamma ray doses on sugar beet

International Nuclear Information System (INIS)

Al-Oudat, M.

1993-01-01

We studied the effect of presowing irradiation simulation on sugar beet seeds in two regions (Deir Elzour and Damascus) and for three successive cropping seasons (1986-1989). Those seeds were irradiated with gamma radiation doses varying from 0.005 to 0.050 kGy in the first region, and from 0.005 to 0.025 kGy in the second region. Results showed that doses varying from 0.005 to 0.05 kGy in Deir Elzour gave a mean yield increase varying from 17.4% to 22.6%. However, doses varying from 0.005 to 0.025 in Damascus gave an increase of the same parameter between 19.5% and 23.8%. The best results for pure sugar yield increase obtained for a dose of 0.015 kGy (27.1% in Deir Elzour and 31.9% in Damascus). Yields on the farm level obtained from presowing irradiated seeds showed an increase in sugar beets when using 0.015 kGy gamma radiation dose. (author)

Investigation of PBAT dosimetric properties for high gamma dose dosimetry

International Nuclear Information System (INIS)

Cunha, Elisete L.; Schimitberger, Thiago

2017-01-01

Poly(butylene adipate-co-terephthalate) (PBAT) is an aliphatic-aromatic copolyester which is biodegradable. It is a non-photoluminescent copolyester that becomes photoluminescent after previous exposure to gamma doses higher than 100 kGy. After the previous high energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a LED source at wavelengths ranging from 370 to 405 nm. In this work we investigated the enhancement of the photoluminescence (PL) and dosimetric properties of PBAT, after exposure to high doses of gamma radiation ranging from 50 to 4,000 kGy. In this investigation we demonstrate that increasing the PBAT film thickness by 100 μm enhances the PL output by 3.5 times, when irradiated with 500 kGy. Also, besides the already known color green brightness, the PL intensity can also be used for high dose dosimetry purposes for doses ranging from 50 to 750 kGy. The FTIR analysis has demonstrated that the there is a linear relationship between peak intensity and dose for doses ranging from 100 and 2,000 kGy for the absorbance peaks at 3,241 cm -1 and 3271 cm -1 , with linear correlation coefficients of 0.9981 and 0.9992, respectively. The results indicate that PBAT has great potential for applications in bio-imaging devices and high gamma dose dosimetry. (author)

Investigation of PBAT dosimetric properties for high gamma dose dosimetry

Energy Technology Data Exchange (ETDEWEB)

Cunha, Elisete L.; Schimitberger, Thiago, E-mail: elisete.cunha@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Oliveira, Cristiana M.; Faria, Luiz O., E-mail: farialo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Poly(butylene adipate-co-terephthalate) (PBAT) is an aliphatic-aromatic copolyester which is biodegradable. It is a non-photoluminescent copolyester that becomes photoluminescent after previous exposure to gamma doses higher than 100 kGy. After the previous high energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a LED source at wavelengths ranging from 370 to 405 nm. In this work we investigated the enhancement of the photoluminescence (PL) and dosimetric properties of PBAT, after exposure to high doses of gamma radiation ranging from 50 to 4,000 kGy. In this investigation we demonstrate that increasing the PBAT film thickness by 100 μm enhances the PL output by 3.5 times, when irradiated with 500 kGy. Also, besides the already known color green brightness, the PL intensity can also be used for high dose dosimetry purposes for doses ranging from 50 to 750 kGy. The FTIR analysis has demonstrated that the there is a linear relationship between peak intensity and dose for doses ranging from 100 and 2,000 kGy for the absorbance peaks at 3,241 cm{sup -1} and 3271 cm{sup -1}, with linear correlation coefficients of 0.9981 and 0.9992, respectively. The results indicate that PBAT has great potential for applications in bio-imaging devices and high gamma dose dosimetry. (author)

Gamma dose rate effect on JFET transistors

International Nuclear Information System (INIS)

Assaf, J.

2011-04-01

The effect of Gamma dose rate on JFET transistors is presented. The irradiation was accomplished at the following available dose rates: 1, 2.38, 5, 10 , 17 and 19 kGy/h at a constant dose of 600 kGy. A non proportional relationship between the noise and dose rate in the medium range (between 2.38 and 5 kGy/h) was observed. While in the low and high ranges, the noise was proportional to the dose rate as the case of the dose effect. This may be explained as follows: the obtained result is considered as the yield of a competition between many reactions and events which are dependent on the dose rate. At a given values of that events parameters, a proportional or a non proportional dose rate effects are generated. No dependence effects between the dose rate and thermal annealing recovery after irradiation was observed . (author)

COSANI-2, Gamma Doses from SABINE Calculation, Activity from ANISN Flux Calculation

International Nuclear Information System (INIS)

Dupont, C.

1975-01-01

1 - Nature of physical problem solved: Retrieval of SABINE and/or ANISN results. Calculates in case of SABINE results the individual contributions of capture gamma rays in each region to the total gamma dose and to the total gamma heating may calculate in case of ANISN new activity rates starting from ANISN flux saved on tape and activity cross sections taken on an ANISN binary library tape. The program can draw on a BENSON plotter any of the following quantities: - group flux; - activity rates; - dose rates; - neutron spectra for SABINE; - neutron or gamma direct or adjoint spectra for ANISN; - gamma heating and dose rate for SABINE including individual contributions from each region. Several ANISN and/or SABINE cases can be drawn on the same graph for comparison purposes. 2 - Restrictions on the complexity of the problem: Maximum number of: - tapes containing ANISN and/or SABINE results: 5; - curves per graph: 3; - regions: 40; - points per curve: 500; - energy groups: 200

Gamma-Ray Doses Affected on Alfalfa (Medicago sativa L.)

International Nuclear Information System (INIS)

Zayed, E.M; Tarrad, M.M.; Abd El-Daem, G.A.N.A.

2013-01-01

Field experiments were conducted at the experimental from, Nuclear Research Center at Inshas. Atomic Energy Authority (AEA) at Egypt during 2011– 2012 growing seasons on alfalfa genotype. The aim of this investigation to evaluate the effect of different gamma ray doses (100-300 Gy) on the alfalfa yield and related traits. Seeds lots of alfalfa genotype were subjected to five gamma ray treatments (100,150,200,250 and 300 Gray). Over all cuts, the dose treatment 300 Gy increased the majority of studied traits i.e., plant height, No. of shoots/plant, fresh weight/plant, fresh yield/Fadden and dry weight yield/fed. The results observed indicated that. In addition, dose of 200 and 250 Gy increased No. of leaves /plant, No. of shoots/plant, stem diameter and fresh weight /plant. However, the plant dry weight was decreased by all doses used and over all cuts, but the dose of 100 and 150 Gy increased leaves /stem ratio. Meanwhile, the later cuts were more affected by irradiation treatments than the earlier ones. In general, the low doses had negative effects on yield traits, but, the relatively high doses exhibited an increase in yield traits

A formalism for independent checking of Gamma Knife dose calculations

International Nuclear Information System (INIS)

Tsai Jensan; Engler, Mark J.; Rivard, Mark J.; Mahajan, Anita; Borden, Jonathan A.; Zheng Zhen

2001-01-01

For stereotactic radiosurgery using the Leksell Gamma Knife system, it is important to perform a pre-treatment verification of the maximum dose calculated with the Leksell GammaPlan[reg] (D LGP ) stereotactic radiosurgery system. This verification can be incorporated as part of a routine quality assurance (QA) procedure to minimize the chance of a hazardous overdose. To implement this procedure, a formalism has been developed to calculate the dose D CAL (X,Y,Z,d av ,t) using the following parameters: average target depth (d av ), coordinates (X,Y,Z) of the maximum dose location or any other dose point(s) to be verified, 3-dimensional (3-dim) beam profiles or off-center-ratios (OCR) of the four helmets, helmet size i, output factor O i , plug factor P i , each shot j coordinates (x,y,z) i,j , and shot treatment time (t i,j ). The average depth of the target d av was obtained either from MRI/CT images or ruler measurements of the Gamma Knife Bubble Head Frame. D CAL and D LGP were then compared to evaluate the accuracy of this independent calculation. The proposed calculation for an independent check of D LGP has been demonstrated to be accurate and reliable, and thus serves as a QA tool for Gamma Knife stereotactic radiosurgery

Effect of dose and dose rate of gamma radiation on catalytic activity of catalase

International Nuclear Information System (INIS)

Vaclav Cuba; Tereza Pavelkova; Viliam Mucka

2010-01-01

Catalytic activity of gamma irradiated catalase from bovine liver was studied for hydrogen peroxide decomposition at constant temperature and pressure. The measurement was performed at temperatures 27, 32, 37, 42 and 47 deg C. Solutions containing 1 and 0.01 g dm -3 of catalase in phosphate buffer were used for the study. Repeatability of both sample preparation and kinetics measurement was experimentally verified. Rate constants of the reaction were determined for all temperatures and the activation energy was evaluated from Arrhenius plot. Gamma irradiation was performed using 60 Co radionuclide source Gammacell 220 at two different dose rates 5.5 and 70 Gy h -1 , with doses ranging from 10 to 1000 Gy. The observed reaction of irradiated and non-irradiated catalase with hydrogen peroxide is of the first order. Irradiation significantly decreases catalytic activity of catalase, but the activation energy does not depend markedly on the dose. The effect of irradiation is more significant at higher dose rate. (author)

Specific gamma-ray dose constants for nuclides important to dosimetry and radiological assessment

International Nuclear Information System (INIS)

Unger, L.M.; Trubey, D.K.

1982-05-01

Tables of specific gamma-ray dose constants (the unshielded gamma-ray dose equivalent rate at 1 m from a point source) have been computed for approximately 500 nuclides important to dosimetry and radiological assessment. The half life, the mean attenuation coefficient, and thickness for a lead shield providing 95% dose equivalent attenuation are also listed

Skin dose assessment in routine personnel beta/gamma dosimetry

International Nuclear Information System (INIS)

Christensen, P.

1980-01-01

The International Commission on Radiological Protection (Publication 26) has recommended a tissue depth of 5 to 10 mg.cm -2 for skin dose assessments. This requirement is generally not fulfilled by routine monitoring procedures because of practical difficulties in using very thin dosemeters with low sensitivity and therefore a high minimum detectable dose. Especially for low-energy beta-ray exposures underestimations of the skin dose by a factor of more than ten may occur. Low-transparent graphite-mixed sintered LiF and Li 2 B 4 0 7 : Mn dosemeters were produced which show a skin-equivalent response to beta and gamma exposures over a wide range of energies. These have found wide-spread application for extremity dosimetry but have not yet been generally introduced in routine personnel beta/gamma monitoring. The following adaptations of existing routine monitoring systems for improved skin dose assessments have been investigated: 1) Placement of a supplementary, thin, skin-dose equivalent dosemeter in the TLD badge to give additional information on low-energy exposures. 2) Introduction of a second photomultiplier in the read-out chamber which enables a simultaneous determination of emitted TL from both sides of the dosemeter separately. This method makes use of the selfshielding of the dosemeter to give information on the low-energy dose contribution. 3) By diffusion of Li 2 B 4 0 7 into solid LiF-dosemeters it was possible to produce a surface layer with a new distinct glow-peak at about 340 deg C which is not present in the undiffused part of the LiF chip, and which can be utilized for the assessment of the skin-dose. Data on energy response and accuracy of dose measurement for beta/gamma exposures are given for the three methods and advantages and disadvantages are discussed (H.K.)

Linear optical absorption response of poly(vinylidene fluoride - trifluoroethylene) copolymers to high gamma dose

International Nuclear Information System (INIS)

Medeiros, Adriana S.

2009-01-01

Poly(vinylidene fluoride) [PVDF] is a semicrystalline linear homopolymer composed by the repetition of CH 2 - CF 2 monomers. The Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] is a copolymer which is obtained with the random introduction of fluorinated CHF-CF 2 monomers in the PVDF main chain. PVDF, and also its copolymers with TrFE contents ranging from 18 to 63 wt. %, have long been studied for their striking ferroelectric properties and their applications in actuators, transducers and ferroelectric memory. Recent research work around the world have demonstrated that, for TrFE contents ranging from with 30 to 50 wt. %, the copolymer can have its ferroelectric properties modified by high doses of ionizing radiation, with the appearing of radio-induced relaxor ferroelectric features. These studies have lead us to investigate the possible use of these copolymers as high dose dosemeters, once the reported amount of induced C=C conjugated bonds after X-ray, UV and gamma irradiation seems to be a function of the delivered radiation dose. In a first investigation for doses ranging from 0.1 to 100 kGy we found out a linear relation between the gamma radiation dose and the absorption peak intensities in the UV region of the spectrum, i.e., at 223 and 274 nm. The absorption peak at 223 nm is the most sensitive to gamma rays and can be used for detecting gamma doses ranging from 0.3 to 75 kGy. Simultaneously, the absorption peak at 274 nm can be used for doses ranging from 1 to 100 kGy. Now, in the present work, we extended the investigation to gamma doses up to 3 MGy. Particularly, this study is focused in the optical absorption peak at 274 nm, corresponding to the radio-induction of triplets of conjugated C=C double bonds. The investigation revealed a linear correlation between the gamma dose and peak intensity at 274 nm for gamma doses ranging from 0.1 to more than 750 KGy, with a huge extension of the original usable dose range. Calorimetric data revealed a

Analysis of gamma irradiator dose rate using spent fuel elements with parallel configuration

International Nuclear Information System (INIS)

Setiyanto; Pudjijanto MS; Ardani

2006-01-01

To enhance the utilization of the RSG-GAS reactor spent fuel, the gamma irradiator using spent fuel elements as a gamma source is a suitable choice. This irradiator can be used for food sterilization and preservation. The first step before realization, it is necessary to determine the gamma dose rate theoretically. The assessment was realized for parallel configuration fuel elements with the irradiation space can be placed between fuel element series. This analysis of parallel model was choice to compare with the circle model and as long as possible to get more space for irradiation and to do manipulation of irradiation target. Dose rate calculation were done with MCNP, while the estimation of gamma activities of fuel element was realized by OREGEN code with 1 year of average delay time. The calculation result show that the gamma dose rate of parallel model decreased up to 50% relatively compared with the circle model, but the value still enough for sterilization and preservation. Especially for food preservation, this parallel model give more flexible, while the gamma dose rate can be adjusted to the irradiation needed. The conclusion of this assessment showed that the utilization of reactor spent fuels for gamma irradiator with parallel model give more advantage the circle model. (author)

Distribution and characteristics of gamma and cosmic ray dose rate in living environment

International Nuclear Information System (INIS)

Nagaoka, Toshi; Moriuchi, Shigeru

1991-01-01

A series of environmental radiation surveys was carried out from the viewpoint of characterizing the natural radiation dose rate distribution in the living environment, including natural and artificial ones. Through the analysis of the data obtained at numbers of places, several aspects of the radiation field in living environments were clarified. That is the gamma ray dose rate varies due to the following three dominant causes: 1) the radionuclide concentration of surrounding materials acting as gamma ray sources, 2) the spatial distribution of surrounding materials, and 3) the geometrical and shielding conditions between the natural gamma ray sources and the measured point; whereas, the cosmic ray dose rate varies due to the thickness of upper shielding materials. It was also suggested that the gamma ray dose rate generally shows an upward tendency, and the cosmic ray dose rate a downward one in artificial environment. This kind of knowledge is expected to serve as fundamental information for accurate and realistic evaluation of the collective dose in the living environment. (author)

Characteristics of 3D gamma evaluation according to phantom rotation error and dose gradient

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyeong Hyun; Kim, Dong Su; Kim, Tae Ho; Kang, Seong Hee; Shin, Dong Seok; Noh, Yu Yoon; Suh, Tae Seok [Dept. of Biomedical Engineering, Research Institute of Biomedical Engineering, College of Medicine, the Catholic University of Korea, Seoul (Korea, Republic of); Cho, Min Seok [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

2016-12-15

In intensity modulated radiation therapy (IMRT) quality assurance (QA) using dosimetric phantom, a spatial uncertainty induced from phantom set-up inevitably occurs and gamma index that is used to evaluate IMRT plan quality can be affected differently by a combination of the spatial uncertainty and magnitude of dose gradient. In this study, we investigated the impacts of dose gradient and the phantom set-up error on 3D gamma evaluation. In this study, we investigated the characteristics of gamma evaluation according to dose gradient and phantom rotation axis. As a result, 3D gamma had better performance than 2D gamma. Therefore, it can be useful for IMRT QA analysis at clinical field.

Physical changes associated with gamma doses of PM-555 solid-state nuclear track detector

International Nuclear Information System (INIS)

Nouh, S.A.

2004-01-01

The effect of gamma irradiation on the electrical, molecular and structural properties of copolymers of methacrylic esters and olefins, PM-555 solid-state nuclear track detector was investigated. DC conductivity measurements were studied in the temperature range 293-417 K using solid-state samples of the PM-555 polymer. These samples were irradiated with gamma doses in the range 5-63 kGy. Furthermore, the activation energy was measured, at various temperatures, as a function of the gamma dose. It was found that many changes in electrical resistance of PM-555 polymer could be produced by gamma irradiation via the degradation mechanism. Also, the gamma dose gives an advantage for the increasing correlation between the DC conductivity and the number and mobility of the charge carriers created by the ionizing effect of gamma radiation. Moreover, solutions of different loadings (0.2%, 0.4%, 0.6% and 0.8%) were prepared from the irradiated and non irradiated sheets using pure chloroform as a solvent. The effect of both temperature and gamma dose on the intrinsic viscosity of the liquid samples, as a measure of the mean molecular mass of the PM-555 polymer, were studied. In addition, structural and optical property studies using X-ray diffraction and refractive index measurements were performed on all irradiated and non irradiated PM-555 samples. The results indicate that both the degree of ordering or disordering and the anisotropic character of the PM-555 polymer are dependent on the gamma dose

Calculation of neutron and gamma-ray flux-to-dose-rate conversion factors

International Nuclear Information System (INIS)

Kwon, S.G.; Lee, S.Y.; Yook, C.C.

1981-01-01

This paper presents flux-to-dose-rate conversion factors for neutrons and gamma rays based on the American National Standard Institute (ANSI) N666. These data are used to calculate the dose rate distribution of neutron and gamma ray in radiation fields. Neutron flux-to-dose-rate conversion factors for energies from 2.5 x 10 -8 to 20 MeV are presented; the corresponding energy range for gamma rays is 0.01 to 15 MeV. Flux-to-dose-rate conversion factors were calculated, under the assumption that radiation energy distribution has nonlinearity in the phantom, have different meaning from those values obtained by monoenergetic radiation. Especially, these values were determined with the cross section library. The flux-to-dose-rate conversion factors obtained in this work were in a good agreement to the values presented by ANSI. Those data will be useful for the radiation shielding analysis and the radiation dosimetry in the case of continuous energy distributions. (author)

TL detectors for gamma ray dose measurements in criticality accidents

International Nuclear Information System (INIS)

Miljanic, S.; Zorko, B.; Gregori, B.; Knezevic, Z.

2007-01-01

Determination of gamma ray dose in mixed neutron + gamma ray fields is still a demanding task. Dosemeters used for gamma ray dosimetry are usually in some extent sensitive to neutrons and their response variations depend on neutron energy i.e., on neutron spectra. Besides, it is necessary to take into account the energy dependence of dosemeter responses to gamma rays. In this work, several types of thermoluminescent detectors (TLD) placed in different holders used for gamma ray dose determination in the mixed fields were examined. Dosemeters were from three different institutions: Ruder Boskovic Inst. (RBI), Croatia, Jozef Stefan Inst. (JSI), Slovenia and Autoridad Regulatoria Nuclear (ARN), Argentina. All dosemeters were irradiated during the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002. Three accidental scenarios were reproduced and in each irradiation the dosemeters were exposed placed on the front of phantom and 'free in air'. Following types of TLDs were used: 7 LiF (TLD-700), CaF 2 :Mn and Al2 O3 :Mg,Y - all from RBI; CaF 2 :Mn from JSI and 7 LiF (TLD-700) from ARN. Reported doses were compared with the reference values as well as with the values obtained from the results of all participants. The results show satisfactory agreement with other dosimetry systems used in the Intercomparison. The influence of different types of holders and applied corrections of dosemeters' readings are discussed. (authors)

TL detectors for gamma ray dose measurements in criticality accidents.

Science.gov (United States)

Miljanić, Saveta; Zorko, Benjamin; Gregori, Beatriz; Knezević, Zeljka

2007-01-01

Determination of gamma ray dose in mixed neutron+gamma ray fields is still a demanding task. Dosemeters used for gamma ray dosimetry are usually in some extent sensitive to neutrons and their response variations depend on neutron energy i.e., on neutron spectra. Besides, it is necessary to take into account the energy dependence of dosemeter responses to gamma rays. In this work, several types of thermoluminescent detectors (TLD) placed in different holders used for gamma ray dose determination in the mixed fields were examined. Dosemeters were from three different institutions: Ruder Bosković Institute (RBI), Croatia, JoZef Stefan Institute (JSI), Slovenia and Autoridad Regulatoria Nuclear (ARN), Argentina. All dosemeters were irradiated during the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002. Three accidental scenarios were reproduced and in each irradiation the dosemeters were exposed placed on the front of phantom and 'free in air'. Following types of TLDs were used: 7LiF (TLD-700), CaF2:Mn and Al2O3:Mg,Y-all from RBI; CaF2:Mn from JSI and 7LiF (TLD-700) from ARN. Reported doses were compared with the reference values as well as with the values obtained from the results of all participants. The results show satisfactory agreement with other dosimetry systems used in the Intercomparison. The influence of different types of holders and applied corrections of dosemeters' readings are discussed.

American National Standard: neutron and gamma-ray flux-to-dose rate factors

International Nuclear Information System (INIS)

Anon.

1977-01-01

This Standard presents data recommended for computing biological dose rates due to neutron and gamma-ray radiation fields. Neutron flux-to-dose-rate conversion factors for energies from 2.5 x 10 -8 to 20 MeV are given; the energy range for the gamma-ray conversion factors is 0.01 to 15 MeV. Specifically, this Standard is intended for use by shield designers to calculate wholebody dose rates to radiation workers and the general public. Establishing dose-rate limits is outside the scope of this Standard. Use of this Standard in cases where the dose equivalents are far in excess of occupational exposure guidelines is not recommended

Gamma regularization based reconstruction for low dose CT

International Nuclear Information System (INIS)

Zhang, Junfeng; Chen, Yang; Hu, Yining; Luo, Limin; Shu, Huazhong; Li, Bicao; Liu, Jin; Coatrieux, Jean-Louis

2015-01-01

Reducing the radiation in computerized tomography is today a major concern in radiology. Low dose computerized tomography (LDCT) offers a sound way to deal with this problem. However, more severe noise in the reconstructed CT images is observed under low dose scan protocols (e.g. lowered tube current or voltage values). In this paper we propose a Gamma regularization based algorithm for LDCT image reconstruction. This solution is flexible and provides a good balance between the regularizations based on l 0 -norm and l 1 -norm. We evaluate the proposed approach using the projection data from simulated phantoms and scanned Catphan phantoms. Qualitative and quantitative results show that the Gamma regularization based reconstruction can perform better in both edge-preserving and noise suppression when compared with other norms. (paper)

Aging of magnesium stearate under high doses gamma irradiation and oxidative conditions

Energy Technology Data Exchange (ETDEWEB)

Lebeau, D.; Beuvier, L.; Cornaton, M. [CEA, DEN, DPC, SECR, LRMO, F-91191 Gif-sur-Yvette (France); Miserque, F. [CEA, DEN, DPC, SCCME, LECA, F-91191 Gif-sur-Yvette (France); Tabarant, M. [CEA, DEN, DPC, SEARS, LISL, F-91191 Gif-sur-Yvette (France); Esnouf, S. [CEA, DEN, DPC, SECR, LRMO, F-91191 Gif-sur-Yvette (France); Ferry, M., E-mail: muriel.ferry@cea.fr [CEA, DEN, DPC, SECR, LRMO, F-91191 Gif-sur-Yvette (France)

2015-05-15

Highlights: • Magnesium stearate was radio-oxidized at very high doses using gamma-rays. • H{sub 2} emission was estimated as a function of the integrated dose. • Modifications in the organic solid were followed as a function of the integrated dose. • A non-exhaustive degradation mechanism of magnesium stearate was proposed. - Abstract: In nuclear waste packages conditioning processes, magnesium stearate is widely used because of its high lubricating properties. For safety purposes, the radiolytic degradation of these organic materials has to be better understood to be able to predict their aging in repository conditions. This study reports the radiolytic degradation of magnesium stearate, using gamma-rays at room temperature and under air. Modifications were followed using different analytical tools (XPS, ATR-FTIR, ICP-AES, ATG and mass spectrometry). It has been observed that molecules mainly formed up to 1000 kGy of gamma irradiation dose under radio-oxidation are alkanes, hydroperoxides, double bonds in the aliphatic chain, carboxylates with aliphatic chain shorter than the one of stearate and ketones. At a dose of 4000 kGy, dicarboxylic acids are observed: the formation of these molecules needs a dose of at least 1000 kGy to be created under radio-oxidation. These observations allow us to propose a non-exhaustive degradation mechanism of magnesium stearate under gamma-irradiation at room temperature and under air.

TL detectors for gamma-ray dose measurements in critically accidents

International Nuclear Information System (INIS)

Miljanic, S.; Knezevic, Z.; Zorko, B.; Gregori, B.

2005-01-01

Full text: Determination of gamma-ray dose in mixed neutron + gamma-ray fields is still a challenging task. Dosemeters used for gamma-ray dosimetry are usually in some extent sensitive to neutrons and their response variations depend on neutron energy i.e. on neutron spectra. Besides, it is necessary to take into account the energy dependence of dosimeter responses to gamma-rays. To reduce all these influences, design of dosemeter holders is of special importance. In this work, several types of thermoluminescent detectors (TLD) placed in different holders used for gamma-ray dose determination in mixed fields were examined. Dosemeters were from three different institutions: Ruder Boscovic Institute (RBI), Croatia, Jozef Stefan Institute (JSI), Slovenia and Autoridad Regulatoria Nuclear (ARN), Argentina. All dosemeters were irradiated during the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002. At that exercise three accidental scenarios were reproduced: bare reactor, free evolution; lead shielded reactor, steady state; and lead shielded reactor, free evolution. In each irradiation dosemeters were exposed placed on the front of phantom and 'free-in-air'. Also, dosemeters were irradiated in a pure gamma ray field of 60 Co source. Following types of TLDs were used: 7 LiF (TLD-700), CaF 2 :Mn and AI 2 O 3 :Mg,Y - all from RBI; CaF 2 :Mn from JSI and 7 LiF (TLD-700) from ARN. Reported doses were compared with the reference values as well as with the mean participants' values. The results show satisfactory agreement with other dosimetry systems used in the Intercomparison. The influence of different types of holders and applied corrections of dosemeters' readings are discussed. (author)

SU-E-T-453: Optimization of Dose Gradient for Gamma Knife Radiosurgery.

Science.gov (United States)

Sheth, N; Chen, Y; Yang, J

2012-06-01

The goals of stereotactic radiosurgery (SRS) are the ablation of target tissue and sparing of critical normal tissue. We develop tools to aid in the selection of collimation and prescription (Rx) isodose line to optimize the dose gradient for single isocenter intracranial stereotactic radiosurgery (SRS) with GammaKnife 4C utilizing the updated physics data in GammaPlan v10.1. Single isocenter intracranial SRS plans were created to treat the center of a solid water anthropomorphism head phantom for each GammaKnife collimator (4 mm, 8 mm, 14 mm, and 18 mm). The dose gradient, defined as the difference of effective radii of spheres equal to half and full Rx volumes, and Rx treatment volume was analyzed for isodoses from 99% to 20% of Rx. The dosimetric data on Rx volume and dose gradient vs. Rx isodose for each collimator was compiled into an easy to read nomogram as well as plotted graphically. The 4, 8, 14, and 18 mm collimators have the sharpest dose gradient at the 64%, 70%, 76%, and 77% Rx isodose lines, respectively. This corresponds to treating 4.77 mm, 8.86 mm, 14.78 mm, and 18.77 mm diameter targets with dose gradients radii of 1.06 mm, 1.63 mm, 2.54 mm, and 3.17 mm, respectively. We analyzed the dosimetric data for the most recent version of GammaPlan treatment planning software to develop tools that when applied clinically will aid in the selection of a collimator and Rx isodose line for optimal dose gradient and target coverage for single isocenter intracranial SRS with GammaKnife 4C. © 2012 American Association of Physicists in Medicine.

Neurogenic Effects of Low-Dose Whole-Body HZE (Fe) Ion and Gamma Irradiation.

Science.gov (United States)

Sweet, Tara B; Hurley, Sean D; Wu, Michael D; Olschowka, John A; Williams, Jacqueline P; O'Banion, M Kerry

2016-12-01

Understanding the dose-toxicity profile of radiation is critical when evaluating potential health risks associated with natural and man-made sources in our environment. The purpose of this study was to evaluate the effects of low-dose whole-body high-energy charged (HZE) iron (Fe) ions and low-energy gamma exposure on proliferation and differentiation of adult-born neurons within the dentate gyrus of the hippocampus, cells deemed to play a critical role in memory regulation. To determine the dose-response characteristics of the brain to whole-body Fe-ion vs. gamma-radiation exposure, C57BL/6J mice were irradiated with 1 GeV/n Fe ions or a static 137 Cs source (0.662 MeV) at doses ranging from 0 to 300 cGy. The neurogenesis was analyzed at 48 h and one month postirradiation. These experiments revealed that whole-body exposure to either Fe ions or gamma radiation leads to: 1. An acute decrease in cell division within the dentate gyrus of the hippocampus, detected at doses as low as 30 and 100 cGy for Fe ions and gamma radiation, respectively; and 2. A reduction in newly differentiated neurons (DCX immunoreactivity) at one month postirradiation, with significant decreases detected at doses as low as 100 cGy for both Fe ions and gamma rays. The data presented here contribute to our understanding of brain responses to whole-body Fe ions and gamma rays and may help inform health-risk evaluations related to systemic exposure during a medical or radiologic/nuclear event or as a result of prolonged space travel.

Gamma dose effects valuation on micro computing components; Evaluation des effets de la dose gamma sur les composants micro-informatiques

Energy Technology Data Exchange (ETDEWEB)

Joffre, F

1996-12-31

Robotics in hostile environment raises the problem of micro computing components resistance with gamma radiation cumulated dose. The current aim is to reach a dose of 3000 grays with industrial components. A methodology and an instrumentation adapted to test this type of components have been developed. The aim of this work is to present the advantages and disadvantages bound to the use of industrial components in the presence of gamma radiation. After an analysis of the criteria allowing to justify the technological choices, the different steps which characterize the selection and the assessment methodology used are explained. The irradiation and measures means now operational are mentioned. Moreover, the supply aspects of the chosen components for the design of an industrialized system is taken into account. These selection and assessment components contribute to the development and design of computers for civil nuclear robotics. (O.M.). 7 refs.

Determination of gamma ray doses suitable for mutation induction in garlic (Allium sativum L.)

International Nuclear Information System (INIS)

Al-Safadi, Bassam; Ayyoubi, Zouhair

1993-04-01

Garlic (Allium sativum L.) cloves were exposed to different doses of gamma radiation (Control, 100, 250, 500, 750, and 1000 rads). The cloves were planted in 4 replicates at Deer Alhajar station of the Dept. of Radiation Agriculture. Number of surviving plants was recorded at 2 months after planting and at harvest. Length of foliage was measured at harvest time and weight of cloves was taken two weeks after harvest. Visual readings in the field on plant shape and leaf color were also taken. The results indicated a negative effect of gamma radiation on plant survival especially at doses of 750 and 1000 rads where no plants survived until harvest. Plant length and clove weight were reduced even at 500 rad dose. Percentage of yellow and necrotic plants increased with increasing gamma ray dosage. No stimulation of plant growth was noticed as a result of irradiation with low doses of gamma rays. Treatment with 500 rads of gamma radiation was considered the best among tested doses for garlic mutagenesis (Using cloves) since it gave acceptable rate of survival and morphologic variation. (author). 14 refs., 4 figs

Effect of low doses gamma irradiation of cotton seeds

International Nuclear Information System (INIS)

Al-Oudat, M.; Khalifa, Kh.

1996-01-01

Field experiments and then large scale application of irradiated cotton seeds (C.V. Aleppo-40) were carried out during three seasons (1986, 1987 and 1988) for field experiment at ACSAD Station in Dier-Ezzor and 1988, 1989 and 1990 for large scale application at Euphrate's Basin, Al-Ghab and Salamia, farmers farms. The above areas were selected as they represent major cotton production areas in Syria. The aims of the experiments were to study the effect of low doses of gamma irradiation 0, 5, 10, 20, 30, 40 and 50 Gy on cotton yield and to look for the optimum dose of gamma irradiation to obtain best results. The results show that, there were positive effect (P<0.95) for doses 5-30 Gy in increasing cotton yield. The highest increase was at dose of 10 Gy. which as 19.5% higher than control. For the large scale application using 10 Gy the increase in cotton yield varied from 10-39% compared to control. (author). 11 refs., 6 figs

Monitoring and Analysis of Environmental Gamma Dose Rate around Serpong Nuclear Complex

Directory of Open Access Journals (Sweden)

I.P. Susila

2017-08-01

Full Text Available An environmental radiation monitoring system that continuously measures gamma dose rate around nuclear facilities is an important tool to present dose rate information to the public or authorities for radiological protection during both normal operation and radiological accidents. We have developed such a system that consists of six GM-based device for monitoring the environmental dose rate around Serpong Nuclear Complex. It has operated since 2010. In this study, a description of the system and analysis of measured data are presented. Analysis of the data for the last five years shows that the average dose rate levels were between 84-99 nSv/h which are still lower than terrestrial gamma radiation levels at several other locations in Indonesia. Time series analysis of the monitoring data demonstrates a good agreement between an increase in environmental gamma dose rate and the presence of iodine and argon in the air by in situ measurement. This result indicates that system is also effective for an early warning system in the case of radiological emergency.

Organ doses for foetuses, babies, children and adults from environmental gamma rays

International Nuclear Information System (INIS)

Petoussi, N.; Jacob, P.; Zankl, M.; Saito, K.

1991-01-01

Organ doses for babies, children and adults and doses to foetuses from environmental gamma rays were calculated using Monte Carlo codes. Firstly, gamma ray fields in the air-over-ground geometry were simulated, neglecting the disturbances of the radiation field by the human body. The exposure modes considered were semi-infinite homogeneous volume sources in the air, infinite plane sources at a depth of 0.5 g.cm -2 in the ground and homogeneous volume sources of natural radionuclides in the ground. The results of the simulation of the gamma ray transport in the air-over-ground geometry were used as sources irradiating the anthropomorphic phantoms: an 8 week old baby, a seven year old child and two 'reference' adult phantoms of a male and a female. The dose to foetuses were estimated from the dose to the uterus of the adult female. Dose conversion factors normalised to source intensity and air kerma were calculated for monoenergetic sources (15 keV to 10 MeV) and natural and artificial radionuclides. (author)

Isodose mapping of terrestrial gamma radiation dose rate of Selangor state, Kuala Lumpur and Putrajaya, Malaysia

International Nuclear Information System (INIS)

Sanusi, M.S.M.; Ramli, A.T.; Gabdo, H.T.; Garba, N.N.; Heryanshah, A.; Wagiran, H.; Said, M.N.

2014-01-01

A terrestrial gamma radiation survey for the state of Selangor, Kuala Lumpur and Putrajaya was conducted to obtain baseline data for environmental radiological health practices. Based on soil type, geological background and information from airborne survey maps, 95 survey points statistically representing the study area were determined. The measured doses varied according to geological background and soil types. They ranged from 17 nGy h −1 to 500 nGy h −1 . The mean terrestrial gamma dose rate in air above the ground was 182 ± 81 nGy h −1 . This is two times higher than the average dose rate of terrestrial gamma radiation in Malaysia which is 92 nGy h −1 (UNSCEAR 2000). An isodose map was produced to represent exposure rate from natural sources of terrestrial gamma radiation. - Highlights: • A methodology is presented to reduce terrestrial gamma dose rate field survey. • Geological background of acid intrusive of granitic type has the highest dose rates. • The mean dose rate is 2 times higher than the world average. • Isodose map of terrestrial gamma radiation for Selangor, Kuala Lumpur and Putrajaya was produced

Ionizing radiation population doses at Sao Paulo city, Brazil: open-pit gamma dose measurement

International Nuclear Information System (INIS)

Oliveira, Raimundo Enoch Rodrigues

2001-01-01

The effects of ionizing radiation to the human beings are well known for high and intermediate doses. As far as low level) radiation doses are concerned, there is no consensus. In order to get a better understanding of such effects it is necessary to assess the low doses with better accuracy. In this work, it was made an estimate of the annual ambient dose equivalent (H * (10)) to which the people are exposed in the city of Sao Paulo. Until now there are no data about it available in the literature. For the purpose of this evaluation, a map with various routes covering the largest and more representative area of the city was designed. The choice of points for data collection was made taking into account mainly the occupancy of the region. A portable gamma spectrometry system was used. It furnishes the rate of H * (10) and the measured gamma spectrum (in the range from 50 to 1670 keV) in the place of interest. The measurements were performed in a short time interval, since the gamma radiation arrives from a great extent of soil. Each measurement was done 1 m above the soil during 300 s. The rates of H * (10) varied from 33.1 to 152.3 nSv.h -1 , net values, obtained after subtraction of the cosmic rays contribution. The standard deviation was 22 n Sv.h -1 for an average for the city of Sao Paulo of 96.1(24) nSv.h -1 . In addition, average values of H * (10) rates for the city Health Divisions were calculated. Those values are not statistically equivalent and the whole set of data could not be treated as one, as the statistical Student test indicated a non homogeneity of the group of data. Hence it is necessary the accomplishment of a more detailed survey in order to verify the origin of the discrepancy. The mean value of H * (10) rate obtained for the city of Sao Paulo as converted to effective dose. in order to be compared with other places results It could be noticed that the annual average of effective dose for the city of Sao Paulo, 0.522(13) mSv, is superior to

Use of prompt gamma emissions from polyethylene to estimate neutron ambient dose equivalent

Energy Technology Data Exchange (ETDEWEB)

Priyada, P.; Sarkar, P.K., E-mail: pradip.sarkar@manipal.edu

2015-06-11

The possibility of using measured prompt gamma emissions from polyethylene to estimate neutron ambient dose equivalent is explored theoretically. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of a high density polyethylene cylinder to emit prompt gammas from interaction of neutrons with the nuclei of hydrogen and carbon present in polyethylene. The neutron energy dependent responses of hydrogen and carbon nuclei are combined appropriately to match the energy dependent neutron fluence to ambient dose equivalent conversion coefficients. The proposed method is tested initially with simulated spectra and then validated using experimental measurements with an Am–Be neutron source. Experimental measurements and theoretical simulations have established the feasibility of estimating neutron ambient dose equivalent using measured neutron induced prompt gammas emitted from polyethylene with an overestimation of neutron dose at very low energies. - Highlights: • A new method for estimating H{sup ⁎}(10) using prompt gamma emissions from HDPE. • Linear combination of 2.2 MeV and 4.4 MeV gamma intensities approximates DCC (ICRP). • Feasibility of the method was established theoretically and experimentally. • The response of the present technique is very similar to that of the rem meters.

Neutron and gamma-ray dose-rates from the Little Boy replica

International Nuclear Information System (INIS)

Plassmann, E.A.; Pederson, R.A.

1984-01-01

We report dose-rate information obtained at many locations in the near vicinity of, and at distances out to 0.64 km from, the Little Boy replica while it was operated as a critical assembly. The measurements were made with modified conventional dosimetry instruments that used an Anderson-Braun detector for neutrons and a Geiger-Mueller tube for gamma rays with suitable electronic modules to count particle-induced pulses. Thermoluminescent dosimetry methods provide corroborative data. Our analysis gives estimates of both neutron and gamma-ray relaxation lengths in air for comparison with earlier calculations. We also show the neutron-to-gamma-ray dose ratio as a function of distance from the replica. Current experiments and further data analysis will refine these results. 7 references, 8 figures

Gamma dose effects valuation on micro computing components

International Nuclear Information System (INIS)

Joffre, F.

1995-01-01

Robotics in hostile environment raises the problem of micro computing components resistance with gamma radiation cumulated dose. The current aim is to reach a dose of 3000 grays with industrial components. A methodology and an instrumentation adapted to test this type of components have been developed. The aim of this work is to present the advantages and disadvantages bound to the use of industrial components in the presence of gamma radiation. After an analysis of the criteria allowing to justify the technological choices, the different steps which characterize the selection and the assessment methodology used are explained. The irradiation and measures means now operational are mentioned. Moreover, the supply aspects of the chosen components for the design of an industrialized system is taken into account. These selection and assessment components contribute to the development and design of computers for civil nuclear robotics. (O.M.)

Assessment of ambient gamma dose rate around a prospective uranium mining area of South India - A comparative study of dose by direct methods and soil radioactivity measurements

Science.gov (United States)

Karunakara, N.; Yashodhara, I.; Sudeep Kumara, K.; Tripathi, R. M.; Menon, S. N.; Kadam, S.; Chougaonkar, M. P.

Indoor and outdoor gamma dose rates were evaluated around a prospective uranium mining region - Gogi, South India through (i) direct measurements using a GM based gamma dose survey meter, (ii) integrated measurement days using CaSO4:Dy based thermo luminescent dosimeters (TLDs), and (iii) analyses of 273 soil samples for 226Ra, 232Th, and 40K activity concentration using HPGe gamma spectrometry. The geometric mean values of indoor and outdoor gamma dose rates were 104 nGy h-1 and 97 nGy h-1, respectively with an indoor to outdoor dose ratio of 1.09. The gamma dose rates and activity concentrations of 226Ra, 232Th, and 40K varied significantly within a small area due to the highly localized mineralization of the elements. Correlation study showed that the dose estimated from the soil radioactivity is better correlated with that measured directly using the portable survey meter, when compared to that obtained from TLDs. This study showed that in a region having localized mineralization in situ measurements using dose survey meter provide better representative values of gamma dose rates.

MO-F-CAMPUS-T-03: Continuous Dose Delivery with Gamma Knife Perfexion

International Nuclear Information System (INIS)

Ghobadi,; Li, W; Chung, C; Jaffray, D; Aleman, D

2015-01-01

Purpose: We propose continuous dose delivery techniques for stereotactic treatments delivered by Gamma Knife Perfexion using inverse treatment planning system that can be applied to various tumour sites in the brain. We test the accuracy of the plans on Perfexion’s planning system (GammaPlan) to ensure the obtained plans are viable. This approach introduces continuous dose delivery for Perefxion, as opposed to the currently employed step-and-shoot approaches, for different tumour sites. Additionally, this is the first realization of automated inverse planning on GammaPlan. Methods: The inverse planning approach is divided into two steps of identifying a quality path inside the target, and finding the best collimator composition for the path. To find a path, we select strategic regions inside the target volume and find a path that visits each region exactly once. This path is then passed to a mathematical model which finds the best combination of collimators and their durations. The mathematical model minimizes the dose spillage to the surrounding tissues while ensuring the prescribed dose is delivered to the target(s). Organs-at-risk and their corresponding allowable doses can also be added to the model to protect adjacent organs. Results: We test this approach on various tumour sizes and sites. The quality of the obtained treatment plans are comparable or better than forward plans and inverse plans that use step- and-shoot technique. The conformity indices in the obtained continuous dose delivery plans are similar to those of forward plans while the beam-on time is improved on average (see Table 1 in supporting document). Conclusion: We employ inverse planning for continuous dose delivery in Perfexion for brain tumours. The quality of the obtained plans is similar to forward and inverse plans that use conventional step-and-shoot technique. We tested the inverse plans on GammaPlan to verify clinical relevance. This research was partially supported by Elekta

MO-F-CAMPUS-T-03: Continuous Dose Delivery with Gamma Knife Perfexion

Energy Technology Data Exchange (ETDEWEB)

Ghobadi,; Li, W; Chung, C; Jaffray, D [Princess Margaret Cancer Centre and University Health Network, Toronto, Ontario (Canada); Aleman, D [University of Toronto, Toronto, Ontario (Canada)

2015-06-15

Purpose: We propose continuous dose delivery techniques for stereotactic treatments delivered by Gamma Knife Perfexion using inverse treatment planning system that can be applied to various tumour sites in the brain. We test the accuracy of the plans on Perfexion’s planning system (GammaPlan) to ensure the obtained plans are viable. This approach introduces continuous dose delivery for Perefxion, as opposed to the currently employed step-and-shoot approaches, for different tumour sites. Additionally, this is the first realization of automated inverse planning on GammaPlan. Methods: The inverse planning approach is divided into two steps of identifying a quality path inside the target, and finding the best collimator composition for the path. To find a path, we select strategic regions inside the target volume and find a path that visits each region exactly once. This path is then passed to a mathematical model which finds the best combination of collimators and their durations. The mathematical model minimizes the dose spillage to the surrounding tissues while ensuring the prescribed dose is delivered to the target(s). Organs-at-risk and their corresponding allowable doses can also be added to the model to protect adjacent organs. Results: We test this approach on various tumour sizes and sites. The quality of the obtained treatment plans are comparable or better than forward plans and inverse plans that use step- and-shoot technique. The conformity indices in the obtained continuous dose delivery plans are similar to those of forward plans while the beam-on time is improved on average (see Table 1 in supporting document). Conclusion: We employ inverse planning for continuous dose delivery in Perfexion for brain tumours. The quality of the obtained plans is similar to forward and inverse plans that use conventional step-and-shoot technique. We tested the inverse plans on GammaPlan to verify clinical relevance. This research was partially supported by Elekta

Dose and dose rate effects of whole-body gamma-irradiation: I. Lymphocytes and lymphoid organs

Science.gov (United States)

Pecaut, M. J.; Nelson, G. A.; Gridley, D. S.

2001-01-01

The major goal of part I of this study was to compare varying doses and dose rates of whole-body gamma-radiation on lymphoid cells and organs. C57BL/6 mice (n = 75) were exposed to 0, 0.5, 1.5, and 3.0 Gy gamma-rays (60Co) at 1 cGy/min (low-dose rate, LDR) and 80 cGy/min (high-dose rate, HDR) and euthanized 4 days later. A significant dose-dependent loss of spleen mass was observed with both LDR and HDR irradiation; for the thymus this was true only with HDR. Decreasing leukocyte and lymphocyte numbers occurred with increasing dose in blood and spleen at both dose rates. The numbers (not percentages) of CD3+ T lymphocytes decreased in the blood in a dose-dependent manner at both HDR and LDR. Splenic T cell counts decreased with dose only in HDR groups; percentages increased with dose at both dose rates. Dose-dependent decreases occurred in CD4+ T helper and CD8+ T cytotoxic cell counts at HDR and LDR. In the blood the percentages of CD4+ cells increased with increasing dose at both dose rates, whereas in the spleen the counts decreased only in the HDR groups. The percentages of the CD8+ population remained stable in both blood and spleen. CD19+ B cell counts and percentages in both compartments declined markedly with increasing HDR and LDR radiation. NK1.1+ natural killer cell numbers and proportions remained relatively stable. Overall, these data indicate that the observed changes were highly dependent on the dose, but not dose rate, and that cells in the spleen are more affected by dose rate than those in blood. The results also suggest that the response of lymphocytes in different body compartments may be variable.

Gamma irradiator dose mapping simulation using the MCNP code and benchmarking with dosimetry

International Nuclear Information System (INIS)

Sohrabpour, M.; Hassanzadeh, M.; Shahriari, M.; Sharifzadeh, M.

2002-01-01

The Monte Carlo transport code, MCNP, has been applied in simulating dose rate distribution in the IR-136 gamma irradiator system. Isodose curves, cumulative dose values, and system design data such as throughputs, over-dose-ratios, and efficiencies have been simulated as functions of product density. Simulated isodose curves, and cumulative dose values were compared with dosimetry values obtained using polymethyle-methacrylate, Fricke, ethanol-chlorobenzene, and potassium dichromate dosimeters. The produced system design data were also found to agree quite favorably with those of the system manufacturer's data. MCNP has thus been found to be an effective transport code for handling of various dose mapping excercises for gamma irradiators

In vitro cell culture lethal dose submitted to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

In vitro cell culture lethal dose submitted to gamma radiation

International Nuclear Information System (INIS)

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

2009-01-01

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

Automatic optimisation of gamma dose rate sensor networks: The DETECT Optimisation Tool

DEFF Research Database (Denmark)

Helle, K.B.; Müller, T.O.; Astrup, Poul

2014-01-01

of the EU FP 7 project DETECT. It evaluates the gamma dose rates that a proposed set of sensors might measure in an emergency and uses this information to optimise the sensor locations. The gamma dose rates are taken from a comprehensive library of simulations of atmospheric radioactive plumes from 64......Fast delivery of comprehensive information on the radiological situation is essential for decision-making in nuclear emergencies. Most national radiological agencies in Europe employ gamma dose rate sensor networks to monitor radioactive pollution of the atmosphere. Sensor locations were often...... source locations. These simulations cover the whole European Union, so the DOT allows evaluation and optimisation of sensor networks for all EU countries, as well as evaluation of fencing sensors around possible sources. Users can choose from seven cost functions to evaluate the capability of a given...

Distributions of neutron and gamma doses in phantom under a mixed field

International Nuclear Information System (INIS)

Beraud-Sudreau, E.

1982-06-01

A calculation program, based on Monte Carlo method, allowed to estimate the absorbed doses relatives to the reactor primary radiation, in a water cubic phantom and in cylindrical phantoms modelized from tissue compositions. This calculation is a theoretical approach of gamma and neutron dose gradient study in an animal phantom. PIN junction dosimetric characteristics have been studied experimentally. Air and water phantom radiation doses measured by PIN junction and lithium 7 fluoride, in reactor field have been compared to doses given by dosimetry classical techniques as tissue equivalent plastic and aluminium ionization chambers. Dosimeter responses have been employed to evaluate neutron and gamma doses in plastinaut (tissue equivalent plastic) and animal (piglet). Dose repartition in the piglet bone medulla has been also determined. This work has been completed by comparisons with Doerschell, Dousset and Brown results and by neutron dose calculations; the dose distribution related to lineic energy transfer in Auxier phantom has been also calculated [fr

Evaluation of skyshine dose due to gamma-rays from a cobalt-60 irradiation facility

International Nuclear Information System (INIS)

Kanazawa, Tamotsu; Okamoto, Shinichi; Ohnishi, Tokuhiro; Tsujii, Yukio

1991-01-01

We attempted to evaluate skyshine dose due to gamma-rays from a cobalt-60 irradiation facility. As the first step, the results of measurements and calculations were compared of the skyshine dose due to gamma-rays from the cobalt-60 source of 1.45 PBq set in the No.4 irradiation room of our laboratory. Distances of measuring points from the cobalt source were in the range from 17 m to about 100 m in the site of our office. Calculation was carried out with simplified single scattering method. The calculated values of the skyshine dose were higher than the measured values. For more precise evaluation of the skyshine dose, the following factors are to be considered; the dose rate distribution on the roof above the source and the attenuation of gamma-rays by air. (author)

Effect of gamma background on the dose absorbed by human embryon and foetus

International Nuclear Information System (INIS)

Miloslavov, V.; Doncheva, B.

1989-01-01

A method is proposed for calculation of absorbed radiation dose in different stages of human foetus development under normal or increased gamma background. On the base of ICRP-data for critical organ's mass (foetus, placenta, blood, uterus) a formula is given for absorbed dose evaluation of gonads. It is concluded that increased gamma background is insignificant compared to internal irradiation from absorbed radionuclides

Dose and dose rate extrapolation factors for malignant and non-malignant health endpoints after exposure to gamma and neutron radiation

Energy Technology Data Exchange (ETDEWEB)

Tran, Van; Little, Mark P. [National Cancer Institute, Radiation Epidemiology Branch, Rockville, MD (United States)

2017-11-15

Murine experiments were conducted at the JANUS reactor in Argonne National Laboratory from 1970 to 1992 to study the effect of acute and protracted radiation dose from gamma rays and fission neutron whole body exposure. The present study reports the reanalysis of the JANUS data on 36,718 mice, of which 16,973 mice were irradiated with neutrons, 13,638 were irradiated with gamma rays, and 6107 were controls. Mice were mostly Mus musculus, but one experiment used Peromyscus leucopus. For both types of radiation exposure, a Cox proportional hazards model was used, using age as timescale, and stratifying on sex and experiment. The optimal model was one with linear and quadratic terms in cumulative lagged dose, with adjustments to both linear and quadratic dose terms for low-dose rate irradiation (<5 mGy/h) and with adjustments to the dose for age at exposure and sex. After gamma ray exposure there is significant non-linearity (generally with upward curvature) for all tumours, lymphoreticular, respiratory, connective tissue and gastrointestinal tumours, also for all non-tumour, other non-tumour, non-malignant pulmonary and non-malignant renal diseases (p < 0.001). Associated with this the low-dose extrapolation factor, measuring the overestimation in low-dose risk resulting from linear extrapolation is significantly elevated for lymphoreticular tumours 1.16 (95% CI 1.06, 1.31), elevated also for a number of non-malignant endpoints, specifically all non-tumour diseases, 1.63 (95% CI 1.43, 2.00), non-malignant pulmonary disease, 1.70 (95% CI 1.17, 2.76) and other non-tumour diseases, 1.47 (95% CI 1.29, 1.82). However, for a rather larger group of malignant endpoints the low-dose extrapolation factor is significantly less than 1 (implying downward curvature), with central estimates generally ranging from 0.2 to 0.8, in particular for tumours of the respiratory system, vasculature, ovary, kidney/urinary bladder and testis. For neutron exposure most endpoints, malignant and

Application of airborne gamma spectrometric survey data to estimating terrestrial gamma-ray dose rates: An example in California

International Nuclear Information System (INIS)

Wollenberg, H.A.; Revzan, K.L.; Smith, A.R.

1992-01-01

The authors examine the applicability of radioelement data from the National Aerial Radiometric Reconnaissance (NARR) to estimate terrestrial gamma-ray absorbed dose rates, by comparing dose rates calculated from aeroradiometric surveys of U, Th, and K concentrations in 1 x 2 degree quadrangles with dose rates calculated from a radiogeologic data base and the distribution of lithologies in California. Gamma-ray dose rates increase generally from north to south following lithological trends. Low values of 25--30 nG/h occur in the northernmost quadrangles where low-radioactivity basaltic and ultramafic rocks predominate. Dose rates then increase southward due to the preponderance of clastic sediments and basic volcanics of the Franciscan Formation and Sierran metamorphics in north central and central California, and to increasing exposure southward of the Sierra Nevada batholith, Tertiary marine sedimentary rocks, intermediate to acidic volcanics, and granitic rocks of the Coast Ranges. High values, to 100 nGy/h occur in southeastern California, due primarily to the presence of high-radioactivity Precambrian and pre Cenozoic metamorphic rocks. Lithologic-based estimates of mean dose rates in the quadrangles generally match those from aeroradiometric data, with statewide means of 63 and 60 nGy/h, respectively. These are intermediate between a population-weighted global average of 51 nGy/h and a weighted continental average of 70 nGy/h, based on the global distribution of rock types. The concurrence of lithologically- and aeroradiometrically- determined dose rates in California, with its varied geology and topography encompassing settings representative of the continents, indicates that the NARR data are applicable to estimates of terrestrial absorbed dose rates from natural gamma emitters

Inhibitory mechanism of low-dose, whole-body irradiation with gamma-rays against tumor metastasis

International Nuclear Information System (INIS)

Yasuhiro Ohsima; Mitsutoshi Tukimoto; Shuji Kojima

2007-01-01

Complete text of publication follows. A lot of beneficial effects of low-dose irradiation are well known. Of them, an inhibitory effect of the radiation on lung metastasis is reported so far. It has been reported that low-dose whole-body irradiation with gamma rays enhanced cytotoxic immune response as one of the mechanisms. In our laboratory, it has been confirmed an enhancement of natural killer activity in mice irradiated with whole-body 0.5Gy gamma-rays. Metastasis is accomplished by multistep process, involving basement membrane destruction, local invasion, intravasation, survival in the bloodstream, extravasation into distant organs, and proliferation at the target site. Besides, a lot of growth factors and proteases are involved in these steps. As to mechanism of inhibition of tumor metastasis induced by low-dose whole-body irradiation, studies from the standpoint of tumor invasion have not been reported. Here, inhibitory effect of 0.5Gy whole-body gamma-ray irradiation on tumor metastasis and its mechanism were examined in pulmonary metastasis model mice injected with B16 melanoma cells. Consequently, 0.5Gy whole-body gamma ray irradiation significantly suppressed colony formation in the lungs. Expression of matrix metalloproteinase- 2 (MMP- 2), a proteinase related to metastasis, in lung tissues was suppressed by the radiation. Alteration of tissue inhibitor of matrix metalloproteinase (TIMP) after the gamma-ray irradiation was examined. Expression of TIMP-1 and TIMP-2 mRNA in the lungs were significantly increased. In order to clarify the inhibitory effect obtained in the in vivo metastatic lung cancer model mice, we studied effects of gamma-rays on cell proliferation, alterations of mRNA and proteins related to tumor metastasis in cultured B16 melanoma cells. Proliferation of B16 melanoma cells was decreased in a dose-dependent manner. MMP-2 mRNA expression was not altered in any doses of gamma-rays. Thought expression of the protein was slightly

Public effective doses from environmental natural gamma exposures indoors and outdoors in Iran

International Nuclear Information System (INIS)

Sohrabi, Mehdi; Roositalab, Jalil; Mohammadi, Jahangir

2015-01-01

The effective doses of public in Iran due to external gamma exposures from terrestrial radionuclides and from cosmic radiation indoors and outdoors of normal natural background radiation areas were determined by measurements and by calculations. For direct measurements, three measurement methods were used including a NaI(TI) scintillation survey meter for preliminary screening, a pressurised ionising chamber for more precise measurements and early warning measurement equipment systems. Measurements were carried out in a large number of locations indoors and outdoors ∼1000 houses selected randomly in 36 large cities of Iran. The external gamma doses of public from living indoors and outdoors were also calculated based on the radioactivity measurements of samples taken from soil and building materials by gamma spectrometry using a high-resolution HPGe system. The national mean background gamma dose rates in air indoors and outdoors based on measurements are 126.9±24.3 and 111.7±17.72 nGy h -1 , respectively. When the contribution from cosmic rays was excluded, the values indoors and outdoors are 109.2±20.2 and 70.2±20.59.4 nGy h -1 , respectively. The dose rates determined for indoors and outdoors by calculations are 101.5±9.2 and 72.2±9.4 nGy h -1 , respectively, which are in good agreement with directly measured dose rates within statistical variations. By considering a population-weighted mean for terrestrial radiation, the ratio of indoor to outdoor dose rates is 1.55. The mean annual effective dose of each individual member of the public from terrestrial radionuclides and cosmic radiation, indoors and outdoors, is 0.86±0.16 mSv y -1 by measurements and 0.8±0.2 mSv y -1 by calculations. The results of this national survey of public annual effective doses from national natural background external gamma radiation determined by measurements and calculations indoors and outdoors of 1000 houses in 36 cities of Iran are presented and discussed. (authors)

Moving from gamma passing rates to patient DVH-based QA metrics in pretreatment dose QA

Energy Technology Data Exchange (ETDEWEB)

Zhen, Heming; Nelms, Benjamin E.; Tome, Wolfgang A. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States); Department of Human Oncology, University of Wisconsin, Madison, Wisconsin 53792 and Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 and Department of Human Oncology, University of Wisconsin, Madison, Wisconsin 53792 (United States)

2011-10-15

Purpose: The purpose of this work is to explore the usefulness of the gamma passing rate metric for per-patient, pretreatment dose QA and to validate a novel patient-dose/DVH-based method and its accuracy and correlation. Specifically, correlations between: (1) gamma passing rates for three 3D dosimeter detector geometries vs clinically relevant patient DVH-based metrics; (2) Gamma passing rates of whole patient dose grids vs DVH-based metrics, (3) gamma passing rates filtered by region of interest (ROI) vs DVH-based metrics, and (4) the capability of a novel software algorithm that estimates corrected patient Dose-DVH based on conventional phan-tom QA data are analyzed. Methods: Ninety six unique ''imperfect'' step-and-shoot IMRT plans were generated by applying four different types of errors on 24 clinical Head/Neck patients. The 3D patient doses as well as the dose to a cylindrical QA phantom were then recalculated using an error-free beam model to serve as a simulated measurement for comparison. Resulting deviations to the planned vs simulated measured DVH-based metrics were generated, as were gamma passing rates for a variety of difference/distance criteria covering: dose-in-phantom comparisons and dose-in-patient comparisons, with the in-patient results calculated both over the whole grid and per-ROI volume. Finally, patient dose and DVH were predicted using the conventional per-beam planar data as input into a commercial ''planned dose perturbation'' (PDP) algorithm, and the results of these predicted DVH-based metrics were compared to the known values. Results: A range of weak to moderate correlations were found between clinically relevant patient DVH metrics (CTV-D95, parotid D{sub mean}, spinal cord D1cc, and larynx D{sub mean}) and both 3D detector and 3D patient gamma passing rate (3%/3 mm, 2%/2 mm) for dose-in-phantom along with dose-in-patient for both whole patient volume and filtered per-ROI. There was

New model for assessing dose and dose rate sensitivity of Gamma ray radiation loss in polarization maintaining optical fibers

International Nuclear Information System (INIS)

Zhang Hongchen; Liu Hai; Qiao Wenqiang; Xue Huijie; He Shiyu

2012-01-01

Highlights: ► Building a new phenomenological theory model to investigate the relation about the irradiation induced loss with irradiation dose and dose rate. ► The Gamma ray irradiation induced loss of the “Capsule” type and “Panda” type polarization maintaining optical fibers at 1310 nm wavelength are investigated. ► The anti irradiation performance of the “Panda” type polarization maintaining optical fiber is better than that of the “Capsule” type polarization maintaining optical fiber, the reason is that the stress region doped by GeO 2 . - Abstract: The Gamma ray irradiation induced loss of the “Capsule” type and “Panda” type polarization maintaining optical fibers at 1310 nm wavelength are investigated. A phenomenological theory model is introduced and the influence of irradiation dose and dose rate on the irradiation induced loss is discussed. The phenomenological theoretical results are consistent with the experimental results of the irradiation induced loss for the two types of polarization maintaining optical fibers. The anti irradiation performance of the “Panda” type polarization maintaining optical fiber is better than that of the “Capsule” type polarization maintaining optical fiber, the reason is that the stress region dope with GeO 2 . Meanwhile, both of the polarization maintaining optical fiber irradiation induced loss increase with increasing the irradiation dose. In the case of same dose, the high dose rate Gamma ray irradiation induced optical fiber losses are higher than that of the low dose rate.

Development of a high sensitivity pinhole type gamma camera using semiconductors for low dose rate fields

Science.gov (United States)

Ueno, Yuichiro; Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi; Fujishima, Yasutake; Yoshida, Akira; Umegaki, Kikuo

2018-06-01

We developed a pinhole type gamma camera, using a compact detector module of a pixelated CdTe semiconductor, which has suitable sensitivity and quantitative accuracy for low dose rate fields. In order to improve the sensitivity of the pinhole type semiconductor gamma camera, we adopted three methods: a signal processing method to set the discriminating level lower, a high sensitivity pinhole collimator and a smoothing image filter that improves the efficiency of the source identification. We tested basic performances of the developed gamma camera and carefully examined effects of the three methods. From the sensitivity test, we found that the effective sensitivity was about 21 times higher than that of the gamma camera for high dose rate fields which we had previously developed. We confirmed that the gamma camera had sufficient sensitivity and high quantitative accuracy; for example, a weak hot spot (0.9 μSv/h) around a tree root could be detected within 45 min in a low dose rate field test, and errors of measured dose rates with point sources were less than 7% in a dose rate accuracy test.

Dose Distribution Calculation Using MCNPX Code in the Gamma-ray Irradiation Cell

International Nuclear Information System (INIS)

Kim, Yong Ho

1991-02-01

60 Co-gamma irradiators have long been used for foods sterilization, plant mutation and development of radio-protective agents, radio-sensitizers and other purposes. The Applied Radiological Science Research Institute of Cheju National University has a multipurpose gamma irradiation facility loaded with a MDS Nordin standard 60 Co source (C188), of which the initial activity was 400 TBq (10,800 Ci) on February 19, 2004. This panoramic gamma irradiator is designed to irradiate in all directions various samples such as plants, cultured cells and mice to administer given radiation doses. In order to give accurate doses to irradiation samples, appropriate methods of evaluating, both by calculation and measurement, the radiation doses delivered to the samples should be set up. Computational models have been developed to evaluate the radiation dose distributions inside the irradiation chamber and the radiation doses delivered to typical biolological samples which are frequently irradiated in the facility. The computational models are based on using the MCNPX code. The horizontal and vertical dose distributions has been calculated inside the irradiation chamber and compared the calculated results with measured data obtained with radiation dosimeters to verify the computational models. The radiation dosimeters employed are a Famer's type ion chamber and MOSFET dosimeters. Radiation doses were calculated by computational models, which were delivered to cultured cell samples contained in test tubes and to a mouse fixed in a irradiation cage, and compared the calculated results with the measured data. The computation models are also tested to see if they can accurately simulate the case where a thick lead shield is placed between the source and detector. Three tally options of the MCNPX code, F4, F5 and F6, are alternately used to see which option produces optimum results. The computation models are also used to calculate gamma ray energy spectra of a BGO scintillator at

Radon survey and soil gamma doses in primary schools of Batman, Turkey.

Science.gov (United States)

Damla, Nevzat; Aldemir, Kamuran

2014-06-01

A survey was conducted to evaluate levels of indoor radon and gamma doses in 42 primary schools located in Batman, southeastern Anatolia, Turkey. Indoor radon measurements were carried out using CR-39 solid-state nuclear track detector-based radon dosimeters. The overall mean annual (222)Rn activity in the surveyed area was found to be 49 Bq m(-3) (equivalent to an annual effective dose of 0.25 mSv). However, in one of the districts (Besiri) the maximum radon value turned out to be 307 Bq m(-3). The estimated annual effective doses are less than the recommended action level (3-10 mSv). It is found that the radon concentration decreases with increasing floor number. The concentrations of natural and artificial radioisotopes were determined using gamma-ray spectroscopy for soil samples collected in close vicinity of the studied schools. The mean gamma activity concentrations in the soil samples were 31, 25, 329 and 12 Bq kg(-1) for (226)Ra, (232)Th, (40)K and (137)Cs, respectively. The radiological parameters such as the absorbed dose rate in air and the annual effective dose equivalent were calculated. These radiological parameters were evaluated and compared with the internationally recommended values.

A simulation study on the dose distribution for a single beam of the gamma knife

International Nuclear Information System (INIS)

Chen, Chin-cheng; Jiang, Shiang-Huei; Lee, Chung-chi; Shiau, Cheng-Ying

2000-01-01

The purpose of this study is to evaluate the impact of the tissue heterogeneity on the dose distribution for a single beam of the gamma knife. The EGS4 Monte Carlo code was used to simulate both depth and radial profiles of the radiation dose in homogeneous and heterogeneous phantoms, respectively. The results are compared with the dose distribution calculated using the mathematical model of Gamma Plan, the treatment planning system of the gamma knife. The skull and sinus heterogeneity were simulated by a Teflon shell and an air shell, respectively. It was found that the tissue heterogeneity caused significant perturbation on the absolute depth dose at the focus as well as on the depth-dose distribution near the phantom surface and/or at the interface but little effect on the radial dose distribution. The effect of the beam aperture on the depth-dose distribution was also investigated in this study. (author)

Dose profile monitoring with carbon ions by means of prompt-gamma measurements

Energy Technology Data Exchange (ETDEWEB)

Testa, E. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France)], E-mail: e.testa@ipnl.in2p3.fr; Bajard, M.; Chevallier, M.; Dauvergne, D.; Le Foulher, F. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France); Freud, N.; Letang, J.M. [Institut National des Sciences Appliquees de Lyon, Laboratoire de Controle Non-Destructif par Rayonnements Ionisants (France); Poizat, J.C.; Ray, C.; Testa, M. [Institut de Physique Nucleaire de Lyon, Universite de Lyon, F-69003 Lyon, Universite Lyon 1 and IN2P3/CNRS, UMR 5822, F-69622 Villeurbanne (France)

2009-03-15

A key point in the quality control of ion therapy is real-time monitoring and imaging of the dose delivered to the patient. Among the possible signals that can be used to make such a monitoring, prompt gamma-rays issued from nuclear fragmentation are possible candidates, provided the correlation between the emission profile and the primary beam range can be established. By means of simultaneous energy and time-of-flight discrimination, we could measure the longitudinal profile of the prompt gamma-rays emitted by 73 MeV/u carbon ions stopping inside a PMMA target. This technique allowed us to minimize the shielding against neutrons and scattered gamma rays, and to find a good correlation between the prompt-gamma profile and the ion range. This profile was studied as a function of the observation angle. By extrapolating our results to higher energies and realistic detection efficiencies, we showed that prompt gamma-ray measurements make it feasible to control in real time the longitudinal dose during ion therapy treatments.

Effects of high dose gamma irradiation on ITO thin film properties

Energy Technology Data Exchange (ETDEWEB)

Alyamani, A. [National Nanotechnology Center, King Abdul-Aziz City for Science and Technology (KACST), Riyadh (Saudi Arabia); Mustapha, N., E-mail: nazirmustapha@hotmail.com [Dept. of Physics, College of Sciences, Al Imam Mohammad Ibn Saud Islamic University, P.O. Box 90950, Riyadh 11623 (Saudi Arabia)

2016-07-29

Transparent thin-film Indium Tin Oxides (ITO) were prepared on 0.7 mm thick glass substrates using a pulsed laser deposition (PLD) process with average thickness of 150 nm. The samples were then exposed to high gamma γ radiation doses by {sup 60}Co radioisotope. The films have been irradiated by performing exposure cycles up to 250 kGy total doses at room temperature. The surface structures before and after irradiation were analysed by x-ray diffraction. Atomic Force Microscopy (AFM) was performed on all samples before and after irradiation to investigate any change in the grain sizes, and also in the roughness of the ITO surface. We investigated the influence of γ irradiation on the spectra of transmittance T, in the ultraviolet-visible-near infrared spectrum using spectrophotometer measurements. Energy band gap E{sub g} was then calculated from the optical spectra for all ITO films. It was found that the optical band gap values decreased as the radiation dose was increased. To compare the effect of the irradiation on refractive index n and extinction coefficient k properties, additional measurements were done on the ITO samples before and after gamma irradiation using an ellipsometer. The optical constants n and k increased by increasing the irradiation doses. Electrical properties such as resistivity and sheet resistance were measured using the four-point probe method. The good optical, electrical and morphological properties maintained by the ITO films even after being exposed to high gamma irradiation doses, made them very favourable to be used as anodes for solar cells and as protective coatings in space windows. - Highlights: • Indium Tin Oxide (ITO) thin films were deposited by pulsed laser deposition. • Effects of Gamma irradiation were investigated. • Changes of optical transmission and electrical properties of ITO films were studied. • Intensity of the diffraction peaks and the film's structure changed with increasing irradiation doses. �

Indoor gamma dose measurements in Gudalore (India) using TLD

International Nuclear Information System (INIS)

Sivakumar, R.; Selvasekarapandian, S.; Mugunthamanikandan, N.; Raghunath, V.M.

2002-01-01

Indoor gamma radiation dose rates were measured inside residential buildings in Gudalore using a CaSO 4 : Dy thermoluminescent dosimeter for 1 year . Significant seasonal variations are observed. The highest dose rate is observed during summer and the lowest in winter. The dose rates observed are between 77.9 and 229.3 nGy h -1 and may be attributed to the type of building materials used in the dwellings monitored. The calculated mean annual effective dose equivalent rates range between 477.6 μSv y -1 , for the inhabitants of mud houses to 1406.3 μSv y -1 , for those living in terrace houses made of cement and brick

Effect of large dose gamma-ray irradiation on polyimide

International Nuclear Information System (INIS)

Morita, Yohsuke; Watanabe, Kiyoshi; Yagyu, Hideki.

1988-01-01

In the radiation environment of atomic energy, space and so on, with the heightening of the performance of equipment, the organic materials having the radiation resistance up to several hundreds MGy have been demanded. Polyimide is one of a small number of the polymers which are considered to be applicable to such environment. However, actually the characteristics as the insulator for such large dose radiation environment have not been sufficiently verified. In this study, the gamma-ray of as large dose as 100 MGy was irradiated on the polyimides having different chemical structure in the air and in nitrogen, and the change of their mechanical and electrical characteristics was elucidated, at the same time, the structural change was examined. The four kinds of polyimides used for the experiment were three kinds of thermosetting type and thermoplastic polyether imide. Co-60 gamma-ray was irradiated at the dose rate of 17 kGy/h at room temperature. The tensile properties, volume resistivity, dielectric tangent, gel fraction, glass transition temperature and IR spectra were examined. In the air, the characteristics lowered by large dose irradiation due to the severance of main chains. In nitrogen, the deterioration was extremely slight, and cross-linking occurred. (K.I.)

The annual terrestrial gamma radiation dose to the population of the urban Christchurch area

International Nuclear Information System (INIS)

Chapman, R.H.

1983-01-01

Natural terrestrial gamma radiation dose rates were measured with a high pressure ionization chamber at 70 indoor (195 site measurements) and 58 outdoor locations in the metropolitan Christchurch area. Based on these site measurements, the average gonad dose rate to the population from natural terrestrial gamma radiation was estimated to be 273+-56 microgray per annum. (auth)

Spatial variation of natural terrestrial gamma-ray dose rates in Brunei

International Nuclear Information System (INIS)

Hu, S.J.; Lai, K.K.; Manato, S.; Kodaira, K.

1998-01-01

A carbon survey of natural terrestrial gamma-rat dose rates along the main roads of the western part of Brunei Darussalam was carried out using two portable type 1.5 φ x 4 NaI(TI) and 1 φ x 2 NaI(TI) scintillation counters. A series of semicontinuous count rates measurements were performed inside a moving vehicle. This yielded equal-distance data which were analysed statistically to obtain the spatial variation of the natural terrestrial gamma-ray dose rates. The equal-distance data of dose rates were obtained by correcting for shielding effect of the car. The thickness of the pavement and the contribution from the pavement material were estimated from a correlation curve between the dose rates measured on pavements and on the nearby soils. A spectral analysis of the equal-distance data enabled us to clarify the structure of the spatial variation in dose rates. The data could be reasonably smoothened by removing the random noise components in a higher wave number region. (author). 6 refs., 7 figs., 1 tab

Gamma and electron high dose dosimetry with rad-hard Si diodes

International Nuclear Information System (INIS)

Pascoalino, Kelly Cristina da Silva

2014-01-01

In this work the main dosimetric characteristics of rad-hard Float Zone (FZ) and magnetic Czochralski (MCz) diodes to electrons (1.5 MeV) and gamma ( 60 Co) radiation are evaluated. The dosimetric system proposed is based on electrical current measurements due to radiation interactions on the devices. The batch response uniformity was studied for the n-type FZ diodes irradiated with gamma rays. The coefficient of variation of the current measurement was about 1.25% at 5 kGy of accumulated dose. A sensitivity decrease with the increase of the accumulated dose (Total Ionizing Dose - TID) was observed for both FZ and MCz diodes. For gamma irradiation, these effect is more pronounced for n-type or smaller resistivity diodes. Two types of dosimetric probe were used on the electron irradiation procedures, one of them specially designed to avoid the deterioration of the electrical contacts and the diodes metallization. The sensitivity of the preirradiated FZ and MCz diodes fell about 10% and 40%, respectively, during electron irradiation at 1.25 MGy of accumulated dose. The effect of electron radiation damage on the electrical properties of the diodes was studied by the means of leakage current and capacitance measurements as a function of bias voltage. The leakage current increases with the accumulated dose but does not contributes significantly to the current signal, since the diodes are operated in photovoltaic mode, without bias voltage. For the MCz diode no change in the full depletion voltage was observed, which indicates its higher tolerance to radiation-induced damage, as expected. During electron irradiation the temperature increases and in order to determine its influence for the current signals, the leakage current values were extrapolated up to 35 °C. The contribution does not exceed 0.1% for FZ and MCz diodes. The effect of the radiation type, electrons or gamma rays, on the pre dose procedures was analyzed for the FZ n-type device and was observed that the

Gamma irradiator dose mapping: a Monte Carlo simulation and experimental measurements

International Nuclear Information System (INIS)

Rodrigues, Rogerio R.; Ribeiro, Mariana A.; Grynberg, Suely E.; Ferreira, Andrea V.; Meira-Belo, Luiz Claudio; Sousa, Romulo V.; Sebastiao, Rita de C.O.

2009-01-01

Gamma irradiator facilities can be used in a wide range of applications such as biological and chemical researches, food treatment and sterilization of medical devices and products. Dose mapping must be performed in these equipment in order to establish plant operational parameters, as dose uniformity, source utilization efficiency and maximum and minimum dose positions. The isodoses curves are generally measured using dosimeters distributed throughout the device, and this procedure often consume a large amount of dosimeters, irradiation time and manpower. However, a detailed curve doses identification of the irradiation facility can be performed using Monte Carlo simulation, which reduces significantly the monitoring with dosimeters. The present work evaluates the absorbed dose in the CDTN/CNEN Gammacell Irradiation Facility, using the Monte Carlo N-particles (MCNP) code. The Gammacell 220, serial number 39, was produced by Atomic Energy of Canada Limited and was loaded with sources of 60 Co. Dose measurements using TLD and Fricke dosimeters were also performed to validate the calculations. The good agreement of the results shows that Monte Carlo simulations can be used as a predictive tool of irradiation planning for the CDTN/CNEN Gamma Cell Irradiator. (author)

Dose mapping simulation using the MCNP code for the Syrian gamma irradiation facility and benchmarking

International Nuclear Information System (INIS)

Khattab, K.; Boush, M.; Alkassiri, H.

2013-01-01

Highlights: • The MCNP4C was used to calculate the gamma ray dose rate spatial distribution in for the SGIF. • Measurement of the gamma ray dose rate spatial distribution using the Chlorobenzene dosimeter was conducted as well. • Good agreements were noticed between the calculated and measured results. • The maximum relative differences were less than 7%, 4% and 4% in the x, y and z directions respectively. - Abstract: A three dimensional model for the Syrian gamma irradiation facility (SGIF) is developed in this paper to calculate the gamma ray dose rate spatial distribution in the irradiation room at the 60 Co source board using the MCNP-4C code. Measurement of the gamma ray dose rate spatial distribution using the Chlorobenzene dosimeter is conducted as well to compare the calculated and measured results. Good agreements are noticed between the calculated and measured results with maximum relative differences less than 7%, 4% and 4% in the x, y and z directions respectively. This agreement indicates that the established model is an accurate representation of the SGIF and can be used in the future to make the calculation design for a new irradiation facility

Neutron/gamma dose separation by the multiple-ion-chamber technique

International Nuclear Information System (INIS)

Goetsch, S.J.

1983-01-01

Many mixed n/γ dosimetry systems rely on two dosimeters, one composed of a tissue-equivalent material and the other made from a non-hydrogenous material. The paired chamber technique works well in fields of neutron radiation nearly identical in spectral composition to that in which the dosimeters were calibrated. However, this technique is drastically compromised in phantom due to the degradation of the neutron spectrum. The three-dosimeter technique allows for the fall-off in neutron sensitivity of the two non-hydrogenous dosimeters. Precise and physically meaningful results were obtained with this technique with a D-T source in air and in phantom and with simultaneous D-T neutron and 60 Co gamma ray irradiation in air. The MORSE-CG coupled n/γ three-dimensional Monte Carlo code was employed to calculate neutron and gamma doses in a water phantom. Gamma doses calculated in phantom with this code were generally lower than corresponding ion chamber measurements. This can be explained by the departure of irradiation conditions from ideal narrow-beam geometry. 97 references

Effect of low doses of gamma radiation on alfalfa (Lucerne) yield

Energy Technology Data Exchange (ETDEWEB)

Al-Odat, M; Khalifa, Kh [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Radiation Agriculture

1994-11-01

Presowing seed irradiation has been reported frequently as a useful application of radiation in agriculture to stimulate growth and increase the yield of field and horticulture crops. Lucerne seeds of previous season (local variety) were irradiated by gamma rays Cs sup 1 sup 3 sup 7 source using doses of 5, 10, 15, 20, 30, and 40 Gy at dose rate of 9.2 Gy/min. Then were planted after 7 days from irradiation with unirradiated control in complete randomized block design and 5 replicates for three seasons (1986, 1987, 1988), the field experiment was carried out at ACSAD research station in Der-Ezzor. Also pot experiments were carried out to study the effect of low doses gamma irradiation on seed germination and growth of shoot and root systems of seedlings. The following observation were made on plants grown in the field:- fresh weight and dry weight of shoot system, - seed yield at the end of the experiment. The results show that there is a positive effect of seed irradiation on percentage of germination and root systems of seedling compared with the control. the highest increase in dry weight of shoot and root systems was at doses of 10 and 15 Gy. specially when sowing was 10 days after irradiation. Gamma irradiation doses of 10 and 15 Gy led to significant increases in fresh and dry weight at shoot system in the three seasons. The increases were 17.5% and 14.6% for the doses of 10 and 15 Gy respectively. A considerable increase in seed yield obtained at doses from 10 to 40 Gy, and the seed yield varied from 13.3% to 17.9% Compared with the control. (author). 20 refs., 18 tabs.

Terrestrial gamma radiation dose rates and radiological mapping of Terengganu state, Malaysia

International Nuclear Information System (INIS)

Garba, N.N.

2015-01-01

Measurement of terrestrial gamma radiation dose (TGRD) rates in Terengganu state, Malaysia was carried out from 145 different locations using NaI[Tl] micro roentgen survey meter. The measured TGRD rates ranged from 35 to 340 nGy h -1 with mean value of 150 nGy h -1 . The annual effective dose to population was found to be 0.92 mSv y -1 . The data obtained were used in constructing the gamma isodose map using ArcGis 9.3 which shows the distribution of TGRD rates across the state. (author)

Gamma dose from activation of internal shields in IRIS reactor.

Science.gov (United States)

Agosteo, Stefano; Cammi, Antonio; Garlati, Luisella; Lombardi, Carlo; Padovani, Enrico

2005-01-01

The International Reactor Innovative and Secure is a modular pressurised water reactor with an integral design. This means that all the primary system components, such as the steam generators, pumps, pressuriser and control rod drive mechanisms, are located inside the reactor vessel, which requires a large diameter. For the sake of better reliability and safety, it is desirable to achieve the reduction of vessel embrittlement as well as the lowering of the dose beyond the vessel. The former can be easily accomplished by the presence of a wide downcomer, filled with water, which surrounds the core region, while the latter needs the presence of additional internal shields. An optimal shielding configuration is under investigation, for reducing the ex-vessel dose due to activated internals and for limiting the amount of the biological shielding. MCNP 4C calculations were performed to evaluate the neutron and the gamma dose during operation and the 60Co activation of various shields configurations. The gamma dose beyond the vessel from activation of its structural components was estimated in a shutdown condition, with the Monte Carlo code FLUKA 2002 and the MicroShield software. The results of the two codes are in agreement and show that the dose is sufficiently low, even without an additional shield.

Gamma dose from activation of internal shields in IRIS reactor

International Nuclear Information System (INIS)

Agosteo, S.; Cammi, A.; Garlati, L.; Lombardi, C.; Padovani, E.

2005-01-01

The International Reactor Innovative and Secure is a modular pressurised water reactor with an integral design. This means that all the primary system components, such as the steam generators, pumps, pressurizer and control rod drive mechanisms, are located inside the reactor vessel, which requires a large diameter. For the sake of better reliability and safety, it is desirable to achieve the reduction of vessel embrittlement as well as the lowering of the dose beyond the vessel. The former can be easily accomplished by the presence of a wide downcomer, filled with water, which surrounds the core region, while the latter needs the presence of additional internal shields. An optimal shielding configuration is under investigation, for reducing the ex-vessel dose due to activated internals and for limiting the amount of the biological shielding. MCNP 4C calculations were performed to evaluate the neutron and the gamma dose during operation and the 60 Co activation of various shields configurations. The gamma dose beyond the vessel from activation of its structural components was estimated in a shutdown condition, with the Monte Carlo code FLUKA 2002 and the MicroShield software. The results of the two codes are in agreement and show that the dose is sufficiently low, even without an additional shield. (authors)

Dose mapping of the multi-purpose gamma irradiation facility

Energy Technology Data Exchange (ETDEWEB)

Cabalfin, E G; Lanuza, L G; Villamater, D T [Irradiation Services, Nuclear Services and Training Division, Philippine Nuclear Research Institute, Quezon City (Philippines)

1989-12-01

In radiation processing, reliable dosimetry constitutes a very important part of process control and quality assurance. Radiation dosimetry is the only acceptable method to guarantee that the irradiated product has undergone the correct radiation treatment. In preparation therefore, for the routine operation of the newly installed multi-purpose gamma irradiation facility at the Philippine Nuclear Research Institute (PNRI), dose mapping distribution studies were undertaken. Results of dose distribution in air as well as in dummy product are presented. The effects of product bulk density, product geometry and product to source distance on minimum absorbed dose and uniformity ratio have been determined. (Author).

Dose mapping of the multi-purpose gamma irradiation facility

International Nuclear Information System (INIS)

Cabalfin, E.G.; Lanuza, L.G.; Villamater, D.T.

1989-01-01

In radiation processing, reliable dosimetry constitutes a very important part of process control and quality assurance. Radiation dosimetry is the only acceptable method to guarantee that the irradiated product has undergone the correct radiation treatment. In preparation therefore, for the routine operation of the newly installed multi-purpose gamma irradiation facility at the Philippine Nuclear Research Institute (PNRI), dose mapping distribution studies were undertaken. Results of dose distribution in air as well as in dummy product are presented. The effects of product bulk density, product geometry and product to source distance on minimum absorbed dose and uniformity ratio have been determined. (Author)

Indoor gamma dose measurements in Gudalore (India) using TLD

Energy Technology Data Exchange (ETDEWEB)

Sivakumar, R.; Selvasekarapandian, S. E-mail: spandian@bharathi.ernet.in; Mugunthamanikandan, N.; Raghunath, V.M

2002-06-01

Indoor gamma radiation dose rates were measured inside residential buildings in Gudalore using a CaSO{sub 4} : Dy thermoluminescent dosimeter for 1 year . Significant seasonal variations are observed. The highest dose rate is observed during summer and the lowest in winter. The dose rates observed are between 77.9 and 229.3 nGy h{sup -1} and may be attributed to the type of building materials used in the dwellings monitored. The calculated mean annual effective dose equivalent rates range between 477.6 {mu}Sv y{sup -1}, for the inhabitants of mud houses to 1406.3 {mu}Sv y{sup -1}, for those living in terrace houses made of cement and brick.

Measurement of californium-252 gamma photons depth dose distribution in tissue equivalent material. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

Fadel, M A; El-Fiki, M A; Eissa, H M; Abdel-Hafez, A; Naguib, S H [National Institute of Standards, Cairo (Egypt)

1996-03-01

Phantom of tissue equivalent material with and without bone was used measuring depth dose distribution of gamma-rays from californium-252 source. The source was positioned at center of perspex walled phantom. Depth dose measurements were recorded for X, Y and Z planes at different distances from source. TLD 700 was used for measuring the dose distribution. Results indicate that implantation of bone in tissue equivalent medium cause changes in the gamma depth dose distribution which varies according to variation in bone geometry. 9 figs.

Development of autonomous gamma dose logger for environmental monitoring.

Science.gov (United States)

Jisha, N V; Krishnakumar, D N; Surya Prakash, G; Kumari, Anju; Baskaran, R; Venkatraman, B

2012-03-01

Continuous monitoring and archiving of background radiation levels in and around the nuclear installation is essential and the data would be of immense use during analysis of any untoward incidents. A portable Geiger Muller detector based autonomous gamma dose logger (AGDL) for environmental monitoring is indigenously designed and developed. The system operations are controlled by microcontroller (AT89S52) and the main features of the system are software data acquisition, real time LCD display of radiation level, data archiving at removable compact flash card. The complete system operates on 12 V battery backed up by solar panel and hence the system is totally portable and ideal for field use. The system has been calibrated with Co-60 source (8.1 MBq) at various source-detector distances. The system is field tested and performance evaluation is carried out. This paper covers the design considerations of the hardware, software architecture of the system along with details of the front-end operation of the autonomous gamma dose logger and the data file formats. The data gathered during field testing and inter comparison with GammaTRACER are also presented in the paper. AGDL has shown excellent correlation with energy fluence monitor tuned to identify (41)Ar, proving its utility for real-time plume tracking and source term estimation.

Dosimetric evaluation of lithium carbonate (Li2CO3) as a dosemeter for gamma-radiation dose measurements.

Science.gov (United States)

Popoca, R; Ureña-Núñez, F

2009-06-01

This work reports the possibility of using lithium carbonate as a dosimetric material for gamma-radiation measurements. Carboxi-radical ions, CO(2)(-) and CO(3)(-), arise from the gamma irradiation of Li(2)CO(3), and these radical ions can be quantified by electron paramagnetic resonance (EPR) spectrometry. The EPR-signal response of gamma-irradiated lithium carbonate has been investigated to determine some dosimetric characteristics such as: peak-to-peak signal intensity versus gamma dose received, zero-dose response, signal fading, signal repeatability, batch homogeneity, dose rate effect and stability at different environmental conditions. Using the conventional peak-to-peak method of stable ion radicals, it is concluded that lithium carbonate could be used as a gamma dosemeter in the range of 3-100 Gy.

Crystal growth and thermoluminescence response of NaZr2(PO4)3 at high gamma radiation doses

International Nuclear Information System (INIS)

Ordóñez-Regil, E.; Contreras-Ramírez, A.; Fernández-Valverde, S.M.; González-Martínez, P.R.; Carrasco-Ábrego, H.

2013-01-01

Graphical abstract: -- Highlights: •NaZr 2 (PO 4 ) 3 exposed to gamma doses of 10, 30 and 50 MGy. •Gamma radiation produced growth of the crystal size of the NZP. •Morphology changes were reversible by heating. •Linear relationship between the thermoluminescence and the applied gamma dose. •This property could be useful for high-level gamma dosimetry. -- Abstract: This work describes the synthesis and characterization of NaZr 2 (PO 4 ) 3 . The stability of this material under high doses of gamma radiation was investigated in the range of 10–50 MGy. Samples of unaltered and gamma irradiated NaZr 2 (PO 4 ) 3 were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and thermoluminescence. The results showed that while functional groups were not affected by the gamma irradiation, morphology changes were observed with increasing doses of gamma irradiation. The morphology of the non-irradiated compound is agglomerated flakes; however, irradiation at 10 MGy splits the flakes inducing the formation of well-defined cubes. Gamma irradiation induced the crystal size of the NaZr 2 (PO 4 ) 3 to grow. The heat treatment (973 K) of samples irradiated at 50 MGy resulted in the recovery of the original morphology. Furthermore, the thermoluminescence analysis of the irradiated compound is reported

Evaluation of gamma dose effect on PIN photodiode using analytical model

Science.gov (United States)

Jafari, H.; Feghhi, S. A. H.; Boorboor, S.

2018-03-01

The PIN silicon photodiodes are widely used in the applications which may be found in radiation environment such as space mission, medical imaging and non-destructive testing. Radiation-induced damage in these devices causes to degrade the photodiode parameters. In this work, we have used new approach to evaluate gamma dose effects on a commercial PIN photodiode (BPX65) based on an analytical model. In this approach, the NIEL parameter has been calculated for gamma rays from a 60Co source by GEANT4. The radiation damage mechanisms have been considered by solving numerically the Poisson and continuity equations with the appropriate boundary conditions, parameters and physical models. Defects caused by radiation in silicon have been formulated in terms of the damage coefficient for the minority carriers' lifetime. The gamma induced degradation parameters of the silicon PIN photodiode have been analyzed in detail and the results were compared with experimental measurements and as well as the results of ATLAS semiconductor simulator to verify and parameterize the analytical model calculations. The results showed reasonable agreement between them for BPX65 silicon photodiode irradiated by 60Co gamma source at total doses up to 5 kGy under different reverse voltages.

Effect of low-dose gamma-radiation upon hatchability and weight of chickens

International Nuclear Information System (INIS)

Vilic, M.; Kraljevic, P.; Simpraga, M.; Miljanic, S.

2006-01-01

Full text of publication follows: Although any dose of ionizing radiation has generally been recognized to be detrimental to living being, low dose ionizing radiation seems to invoke primary stimulative effects. Stimulatory effects of low dose ionizing radiation include many aspects such as growth, fecundity and longevity stimulation, accelerated development, enhance biological responses for immune systems, enzymatic repair, physiological functions, and the removal of cellular damage, including prevention and removal of cancers and other diseases. Low dose ionizing radiation might also cause changes in the concentration of some biochemical parameters in blood plasma of chickens such as changes in the concentration of total proteins, glucose and cholesterol. The objective of this study was to determine the effect of low doses of gamma irradiation before incubation and on the seventh day of incubation on hatchability of eggs and body weight of chickens. This study includes three independent experiments. In the first experiment, six-hundred eggs produced by a commercial flock of Avian-line 34, were irradiated by a dose of 0.15 Gy gamma radiation (60 Co) before incubation. In the second experiments also involving six-hundred-line 34 eggs were irradiated by dose of 0.15 Gy gamma radiation on the seventh day of incubation. In the third experiment three-hundred eggs produced by a commercial flock of Ross 308 were irradiated by dose 0.30 Gy gamma irradiation before incubation. Along with the chickens which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups. Hatchability was calculated in terms of all eggs divided with fertile eggs which hatched. The individual weights of the chickens were determined on the first and on the forty second day. Growth data were analyzed statistically by t-test. Irradiation of chicken eggs and embryos at rates o f 0.15 Gy increases

Effect of gamma radiation dose and sensitizer on the physical properties of irradiated natural rubber latex

International Nuclear Information System (INIS)

Komgrit, R.; Thawat, C.; B, Tripob; Wirach, T.

2009-07-01

Full text: The vulcanization of natural rubber latex can be induced by gamma radiation, which enhances cross-linking within the rubber matrix. The purpose of this research is to investigate the effect of gamma radiation dose and sensitizers on the physical properties of irradiated natural rubber. Three sensitizers n-butyl acrylate (n-B A), tetrachloroethylene (C 2 Cl 4 ) and trichloromethane (CHCl 3 ) were mixed with natural rubber latex before irradiation with gamma ray dose varied from 14 to 22 kGy. Results showed that the mixture of three sensitizers with specific ratios effectively induced the cross-linking of natural rubber latex. The cross-linking ratio and improved physical properties increased with increasing gamma dose. Therefore, the mixture ratios of n-B A, C 2 Cl 4 and CHCl 3 have shown to be a critical parameter in the vulcanization of natural rubber latex by gamma radiation

Optical fiber sensor for low dose gamma irradiation monitoring

Science.gov (United States)

de Andrés, Ana I.; Esteban, Ã.`scar; Embid, Miguel

2016-05-01

An optical fiber gamma ray detector is presented in this work. It is based on a Terbium doped Gadolinium Oxysulfide (Gd2O2S:Tb) scintillating powder which cover a chemically etched polymer fiber tip. This etching improves the fluorescence gathering by the optical fiber. The final diameter has been selected to fulfill the trade-off between light gathering and mechanical strength. Powder has been encapsulated inside a microtube where the fiber tip is immersed. The sensor has been irradiated with different air Kerma doses up to 2 Gy/h with a 137Cs source, and the spectral distribution of the fluorescence intensity has been recorded in a commercial grade CCD spectrometer. The obtained signal-to-noise ratio is good enough even for low doses, which has allowed to reduce the integration time in the spectrometer. The presented results show the feasibility for using low cost equipment to detect/measure ionizing radiation as gamma rays are.

Dose-response relationship of {gamma}-H2AX foci induction in human lymphocytes after X-rays exposure

Energy Technology Data Exchange (ETDEWEB)

Mandina, Tania [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/41y 47 Miramar, AP 6195 C. Habana (Cuba); Roch-Lefevre, Sandrine H.; Voisin, Pascale [Institut de Radioprotection et de Surete Nucleaire (IRSN), DRPH, SRBE, LDB, BP17, 92262 Fontenay-aux-Roses (France); Gonzalez, Jorge E.; Lamadrid, Ana I.; Romero, Ivonne [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/41y 47 Miramar, AP 6195 C. Habana (Cuba); Garcia, Omar, E-mail: omar@cphr.edu.cu [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/41y 47 Miramar, AP 6195 C. Habana (Cuba); Voisin, Philippe; Roy, Laurence [Institut de Radioprotection et de Surete Nucleaire (IRSN), DRPH, SRBE, LDB, BP17, 92262 Fontenay-aux-Roses (France)

2011-09-15

Biological dosimeters are recommended for dose estimation in case of human overexposure to ionising radiation. Rapid measurement of {gamma}-H2AX foci as a marker of DNA double-strand breaks (DSB) induction has been recently tested with this purpose. Here we reported a dose-response relationship after X-ray irradiation at different times post-exposure. Blood samples were obtained from several healthy donors and exposed to doses between 0 and 2 Gy. After irradiation, blood samples were incubated at 37 deg. C during 0.5 h, 5 h, and 8 h. Scoring of cells and {gamma}-H2AX foci was performed by software. The dose-response curves for different incubation times were as follows: Y{sub (0.5h)} = 11.66D + 0.15 (R{sup 2} = 0.99), Y{sub (5h)} = 2.44D + 0.15 (R{sup 2} = 0.99), Y{sub (8h)} = 1.57D + 0.22 (R{sup 2} = 0.99). At 0.5 h post-exposure, the dose-response relationship for X-irradiated lymphocytes was similar to the one obtained after gamma-irradiation using the same protocol. On the other hand, the results were not similar after 8 h due to different kinetics after gamma- and X-irradiation. Our results confirm the possibilities of using {gamma}-H2AX foci method for dose estimation in a period from 0.5 h up to 8 h post X-irradiation and support the hypothesis of differences in {gamma}-H2AX foci kinetics after gamma- and X-irradiation in vitro.

Comparison of X-ray and gamma-ray dose-response curves for pink somatic mutations in Tradescantia clone 02

International Nuclear Information System (INIS)

Underbrink, A.G.; Kellerer, A.M.; Mills, R.E.; Sparrow, A.H.; Brookhaven National Lab., Upton, N.Y.

1976-01-01

Microdosimetric data indicate that the mean specific energy, xi, produced by individual charged particles from X rays and gamma rays is different for the two radiation qualities by nearly a factor of two. In order to test whether this influences the initial, linear component in the dose-effect relations, a comparison was made between dose-response curves for pink somatic mutations in Tradescantia clone 02 stamen hairs following X and gamma irradiations. Absorbed doses ranged from 2.66 to 300 rad. The results are in agreement with predictions made on the basis of microdosimetric data. At low doses gamma rays are substantially less effective than X rays. The RBE of gamma rays vs. X rays at low doses was approximately 0.6, a value lower than those usually reported in other experimental systems. (orig.) [de

Radioactivity Risk Assessment of Radon and Gamma Dose at One Uranium Tailings Pond in China

Science.gov (United States)

Lou, Yalong; Liu, Yong; Peng, Guowen; Zhao, Guodong; Zhang, Yan; Yang, Zhu

2018-01-01

A year-long monitoring of gamma radiation effective dose rate and radon concentration had been done in the reservoir area of one uranium tailings pond in Hunan province (The monitoring area included indoor and outdoor area of residential buildings and workshops, tailings dam slope). Afterwards, the annual effective radiation dose of the people in that radiation environment had been calculated based on the results of monitoring, as well as a radiation risk assessment. According to the assessment, gamma radiation effective dose rate and radon concentration in the monitoring area were low, and the annual effective radiation dose was far below the international standard (30mSv), which showed that the radiation would not put the people’s health at risk. However, the annual effective radiation dose of gamma was far above that of radon in the area of uranium tailings pond; therefore, it’s advisable to take quarantine measures in in the area of uranium tailings pond to keep the surrounding residents away from unnecessary ionizing radiation.

Effect of Gamma Irradiation Doses on Some Chemical Characteristics of Cotton Seed Oil

International Nuclear Information System (INIS)

Saleh, O.I.

2011-01-01

Cotton Seeds c.v. Giza 85 (Gossypium hirsutum L.) were exposed to gamma irradiation doses of 0.5, 1.0 and 1.5 kGy to improve some chemical characteristics of cotton seed oil i.e. saturated and unsaturated fatty acids, gossypol and βsitosterol that were bound oil. The presented study showed that, the saturated fatty acids; lauric, palmitic and stearic increased when the cotton seeds were exposed to gamma irradiation doses of 0.5 up to 1.5 kGy, On the other hand, arachidic acid content decreased in all the irradiated treatments compared with untreated cotton seed. The unsaturated fatty acid oleic was increased in irradiated cotton seed samples compared with untreated one, while linoleic, the major unsaturated fatty acid decreased in irradiated cotton seed oil than untreated seeds. Gossypol and βsitosterol, bound oil, in irradiated cotton seeds increased gradually with gamma irradiated doses compared with untreated control samples

Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

International Nuclear Information System (INIS)

Mansonr, S.Z.

2009-01-01

Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

International Nuclear Information System (INIS)

Mansonr, S.Z.

2008-01-01

Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

Suitable gamma ray dose determination in order to induce genetic variation in kaboli chickpea (Cicer Arietinum L)

International Nuclear Information System (INIS)

Naserian Khiabani, B.; Ahari Mostafavi, H.; Fathollahi, H.; Vedadi, S.; Mosavi Shalmani, M. A.

2008-01-01

In spite of chickpea's use in Iran and its ability of being replaced to adjust the shortage of protein in dietary habits, yield production is very low. One of the main reasons for chickpea's low yield production is its sensitiveness to some diseases, pest and environmental stresses. Genetic variation in chickpea is very low, because of its self pollination. In breeding programs, genetic variation plays an essential role so that the induction of genetic variation in plant population is very important for the plant breeders. The induced mutation through different kinds of mutagens is one of the important ways of genetic variation. In this research, first the sensitiveness of four cultivars (ILC.486, Philip86, Bivinich, Jam) were assessed to different gamma ray doses (100, 200, 300, 400 Gy). The results showed that with an increase in gamma ray dose, the growth rate of chickpea's genotypes decreases. In this respect, the decrease of growth rate has a linear relationship with the gamma ray dose and it is independent from the genotypes. The root length is more sensitive to gamma ray doses than its shoot, and it was observed that at the low doses the root growth decreases, comparing to the shoot growth. On the other hand, in high doses of gamma ray growth abrasion (Ageotropism, Albinism and etc.) were observed. Some traits variation (such as leaf shape, leaf size, leaf color, Albinism, etc.) were seen in M 2 generation, and finally to continue the project, three doses of gamma ray (150,200,250) were selected for the next year

Yield and Chemical Composition of Cucumber Treated by Nitrogen Levels and Doses of Gamma Rays

International Nuclear Information System (INIS)

Fath El-Bab, T.Sh.; Abo El-Khier, Om.M.; Abdallah, A.A.G.

2013-01-01

Two field experiments were performed at the Atomic Energy Authority, Experimental farm, Inshas, Egypt during 2010 and 2011 summer growing seasons in sandy soil. The experiments were conducted to study the effect of pre-sowing seeds which treated by gamma irradiation with different doses of 0, 2, 4 and 6 Gy. This was in combination with three rates of nitrogen, fertilizer i.e., 30, 60 and 90 Kg N/fed. The experiments were laid out using drip irrigation system. The obtained results indicated that gamma rays doses showed significant differences on cucumber yield per plot or per Fed., increasing doses of gamma rays gradually increased cucumber yield per plot up to highest dose, i.e., (6 Gy). The highest value of total yield was obtained with the highest nitrogen rate (90 Kg N/fed.). Doses of gamma rays significantly increased total soluble solids (T.S.S.), total Carbohydrates, fats, total protein, NPK and Ca of cucumber fruits. Application of 60 Kg N/fed. recorded the highest values of all above mentioned chemical characters except of total protein with 90 kg N/fed. every all dose treatments. The effect of interaction between doses and fertilizer levels on chemical characters were significant therefore, the highest values was found at 4 Gy and 60 Kg N/fed. treatment for protein, fat, nitrogen and potassium contents while the carbohydrate and calcium contents had the highest value with the treatment of 6 Gy and 60 Kg N/fed

Gamma dose rate changes in buildings in the region of Southeastern Iran using thermoluminescence dosimetry

International Nuclear Information System (INIS)

Jomehzadeh Mahani, A.; Bahreyni Toosi, M.T.

2006-01-01

Introduction: It is important to measure background radiation, because human beings are always exposed to environmental radiation. The terrestrial component of the natural background depends on the compositions of soils and rocks in which are contained. A significant contribution to total dose from natural sources comes from terrestrial radionuclides such as U- 238, Th- 232 and K- 40. The level of gamma dose rate in buildings depends on the climate / weather, ventilation of living environment, local geology, drainage patterns and other factors. The objective of this study was to establishing the distribution of environmental gamma dose rates in the type of building sampled included cement-sand and soil brick buildings. Materials and Methods: Equipments used in this study include: 1-TLD-100 H (LiF: Mg, Cu, P) dosimeters. 2- TLD-Reader 3500 made by Harshaw, USA. In order to determine indoor gamma dose rate, the dosimeters were calibrated at room temperature with Co-60 source. Before using the dosimeters to measure environmental dose they were subjected to the thermal treatment in a normal oven. Two TLDs, were embedded in a 5 mm PMMA mini-phantom to register only gamma ray. 20 buildings for this study chosen randomly throughout Kerman town, southeastern Iran. Inside each building a holder was hung at a height of above 3 m. The period of monitoring of TLDs was 15 days. The TLDs were retrieved from the buildings and taken to the Mashhad university of medical sciences where they were read with a Harshaw TLD reader model 3500. Results: Our results indicate that indoor gamma dose rate ranged from 106 n Sv/h to 133 n Sv/h for cement-sand buildings with an average of 114.72 n Sv/h. For soil buildings the indoor gamma dose rate varied from 86 n Sv/h to 116 n Sv/h with an average of 100.50 n Sv/h. While the average gamma dose rate in cement-sand buildings is highest (114.72 n Sv/h), that of soil buildings is lowest (100.50 n Sv/h). Discussion: Average values vary from building

Hard beta and gamma emissions of 124I. Impact on occupational dose in PET/CT.

Science.gov (United States)

Kemerink, G J; Franssen, R; Visser, M G W; Urbach, C J A; Halders, S G E A; Frantzen, M J; Brans, B; Teule, G J J; Mottaghy, F M

2011-01-01

The hard beta and gamma radiation of 124I can cause high doses to PET/CT workers. In this study we tried to quantify this occupational exposure and to optimize radioprotection. Thin MCP-Ns thermoluminescent dosimeters suitable for measuring beta and gamma radiation were used for extremity dosimetry, active personal dosimeters for whole-body dosimetry. Extremity doses were determined during dispensing of 124I and oral administration of the activity to the patient, the body dose during all phases of the PET/CT procedure. In addition, dose rates of vials and syringes as used in clinical practice were measured. The procedure for dispensing 124I was optimized using newly developed shielding. Skin dose rates up to 100 mSv/min were measured when in contact with the manufacturer's vial containing 370 MBq of 124I. For an unshielded 5 ml syringe the positron skin dose was about seven times the gamma dose. Before optimization of the preparation of 124I, using an already reasonably safe technique, the highest mean skin dose caused by handling 370 MBq was 1.9 mSv (max. 4.4 mSv). After optimization the skin dose was below 0.2 mSv. The highly energetic positrons emitted by 124I can cause high skin doses if radioprotection is poor. Under optimized conditions occupational doses are acceptable. Education of workers is of paramount importance.

A Performance Evaluation of a Notebook PC under a High Dose-Rate Gamma Ray Irradiation Test

Directory of Open Access Journals (Sweden)

Jai Wan Cho

2014-01-01

Full Text Available We describe the performance of a notebook PC under a high dose-rate gamma ray irradiation test. A notebook PC, which is small and light weight, is generally used as the control unit of a robot system and loaded onto the robot body. Using TEPCO’s CAMS (containment atmospheric monitoring system data, the gamma ray dose rate before and after a hydrogen explosion in reactor units 1–3 of the Fukushima nuclear power plant was more than 150 Gy/h. To use a notebook PC as the control unit of a robot system entering a reactor building to mitigate the severe accident situation of a nuclear power plant, the performance of the notebook PC under such intense gamma-irradiation fields should be evaluated. Under a similar dose-rate (150 Gy/h gamma ray environment, the performances of different notebook PCs were evaluated. In addition, a simple method for a performance evaluation of a notebook PC under a high dose-rate gamma ray irradiation test is proposed. Three notebook PCs were tested to verify the method proposed in this paper.

Dose response of alanine and methyl alanine towards gamma and in-situ alpha irradiation

International Nuclear Information System (INIS)

Mohapatra, M.; Rajeswari, B.; Bhide, M.K.; Rane, Vinayak; Kadam, R.M.

2017-01-01

In situ alpha and external gamma dose response of two ESR (electron spin resonance) dosimetric materials namely alanine and methyl alanine were investigated. It was observed that alanine dosimeter had a better dose response in comparison to methyl alanine for the in-situ alpha irradiation by using 239 Pu powder. On the other hand, in case of gamma radiation, methyl alanine was found to have the sensitivity as twice that of alanine. (author)

Prediction of terrestrial gamma dose rate based on geological formations and soil types in the Johor State, Malaysia

International Nuclear Information System (INIS)

Saleh, Muneer Aziz; Ramli, Ahmad Termizi; Hamzah, Khaidzir bin; Alajerami, Yasser; Moharib, Mohammed; Saeed, Ismael

2015-01-01

This study aims to predict and estimate unmeasured terrestrial gamma dose rate (TGDR) using statistical analysis methods to derive a model from the actual measurement based on geological formation and soil type. The measurements of TGDR were conducted in the state of Johor with a total of 3873 measured points which covered all geological formations, soil types and districts. The measurements were taken 1 m above the soil surface using NaI [Ti] detector. The measured gamma dose rates ranged from 9 nGy h −1 to 1237 nGy h −1 with a mean value of 151 nGy h −1 . The data have been normalized to fit a normal distribution. Tests of significance were conducted among all geological formations and soil types, using the unbalanced one way ANOVA. The results indicated strong significant differences due to the different geological formations and soil types present in Johor State. Pearson Correlation was used to measure the relations between gamma dose rate based on geological formation and soil type (D G,S ) with the gamma dose rate based on geological formation (D G ) or soil type (D s ). A very good correlation was found between D G,S and D G or D G,S and D s . A total of 118 pairs of geological formations and soil types were used to derive the statistical contribution of geological formations and soil types to gamma dose rates. The contribution of the gamma dose rate from geological formation and soil type were found to be 0.594 and 0.399, respectively. The null hypotheses were accepted for 83% of examined data, therefore, the model could be used to predict gamma dose rates based on geological formation and soil type information. - Highlights: • A very good correlation coefficient was found between D G,S and D G or D G,S and D s . • The contribution of the gamma dose rate from geological formation (GDR) is 0.594. • The contribution of the GDR from soil type was found to be 0.399. • A 83% of examined data were accepted the null hypotheses. • The model

Development of autonomous gamma dose logger for environmental monitoring

Energy Technology Data Exchange (ETDEWEB)

Jisha, N. V.; Krishnakumar, D. N.; Surya Prakash, G.; Kumari, Anju; Baskaran, R.; Venkatraman, B. [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

2012-03-15

Continuous monitoring and archiving of background radiation levels in and around the nuclear installation is essential and the data would be of immense use during analysis of any untoward incidents. A portable Geiger Muller detector based autonomous gamma dose logger (AGDL) for environmental monitoring is indigenously designed and developed. The system operations are controlled by microcontroller (AT89S52) and the main features of the system are software data acquisition, real time LCD display of radiation level, data archiving at removable compact flash card. The complete system operates on 12 V battery backed up by solar panel and hence the system is totally portable and ideal for field use. The system has been calibrated with Co-60 source (8.1 MBq) at various source-detector distances. The system is field tested and performance evaluation is carried out. This paper covers the design considerations of the hardware, software architecture of the system along with details of the front-end operation of the autonomous gamma dose logger and the data file formats. The data gathered during field testing and inter comparison with GammaTRACER are also presented in the paper. AGDL has shown excellent correlation with energy fluence monitor tuned to identify {sup 41}Ar, proving its utility for real-time plume tracking and source term estimation.

Standardization of high-dose measurement of electron and gamma ray absorbed doses and dose rates

International Nuclear Information System (INIS)

McLaughlin, W.L.

1985-01-01

Intense electron beams and gamma radiation fields are used for sterilizing medical devices, treating municipal wastes, processing industrial goods, controlling parasites and pathogens, and extending the shelf-life of foods. Quality control of such radiation processes depends largely on maintaining measurement quality assurance through sound dosimetry procedures in the research leading to each process, in the commissioning of that process, and in the routine dose monitoring practices. This affords documentation as to whether satisfactory dose uniformity is maintained throughout the product and throughout the process. Therefore, dosimetry at high doses and dose rates must in many radiation processes be standardized carefully, so that 'dosimetry release' of a product is verified. This standardization is initiated through preliminary dosimetry intercomparison studies such as those sponsored recently by the IAEA. This is followed by establishing periodic exercises in traceability to national or international standards of absorbed dose and dose rate. Traceability is achieved by careful selection of dosimetry methods and proven reference dosimeters capable of giving sufficiently accurate and precise 'transfer' dose assessments: (1) they must be calibrated or have well-established radiation-yield indices; (2) their radiation response characteristics must be reproducible and cover the dose range of interest; (3) they must withstand the rigours of back-and-forth mailing between a central standardizing laboratory and radiation processing facilities, without excessive errors arising due to instabilities, dosimeter batch non-uniformities, and environmental and handling stresses. (author)

Effects of low-dose gamma and neutron radiation on genotoxicity and cytotoxicity of reticulocytes in a mouse model

International Nuclear Information System (INIS)

Phan, N.; McFarlane, N.M.; Lemon, J.; Boreham, D.R.

2008-01-01

Using a successful new automation of micronucleated reticulocyte (MN-RET) scoring, the effects of low-dose (< 1.0 Gy) gamma and neutron radiation on genotoxicity and cytotoxicity of reticulocytes (RET) in a mouse model were investigated. Gamma and neutron irradiation induced significant (p<0.001) increases in the levels of %MN-RET and decreases in the levels of %RET (p<0.001) as the dose level increased. Increasing dose levels showed that gamma radiation induced significantly (p<0.05) more %MN-RET and more %RET than neutron radiation. The results suggest that neutron irradiation may be more cytotoxic (less %RET) than gamma irradiation; however, gamma irradiation may be producing cells with more chromosomal aberrations (more %MN-RET) than neutron irradiation. (author)

Effects of low-dose gamma and neutron radiation on genotoxicity and cytotoxicity of reticulocytes in a mouse model

Energy Technology Data Exchange (ETDEWEB)

Phan, N.; McFarlane, N.M.; Lemon, J.; Boreham, D.R. [McMaster Univ., Medical Physics and Applied Radiation Sciences Unit, Hamilton, Ontario (Canada)

2008-07-01

Using a successful new automation of micronucleated reticulocyte (MN-RET) scoring, the effects of low-dose (< 1.0 Gy) gamma and neutron radiation on genotoxicity and cytotoxicity of reticulocytes (RET) in a mouse model were investigated. Gamma and neutron irradiation induced significant (p<0.001) increases in the levels of %MN-RET and decreases in the levels of %RET (p<0.001) as the dose level increased. Increasing dose levels showed that gamma radiation induced significantly (p<0.05) more %MN-RET and more %RET than neutron radiation. The results suggest that neutron irradiation may be more cytotoxic (less %RET) than gamma irradiation; however, gamma irradiation may be producing cells with more chromosomal aberrations (more %MN-RET) than neutron irradiation. (author)

Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

Energy Technology Data Exchange (ETDEWEB)

Cantinha, Rebeca S.; Nakano, Eliana [Instituto Butantan, Sao Paulo, SP (Brazil). Lab. de Parasitologia], e-mail: rebecanuclear@gmail.com, e-mail: eliananakano@butantan.gov.br; Borrely, Sueli I. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes], e-mail: sborrely@ipen.br; Amaral, Ademir; Melo, Ana M.M.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia (GERAR)], e-mail: amaral@ufpe.br; Silva, Luanna R.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia. Lab. de Radiobiologia], e-mail: amdemelo@hotmail.com, e-mail: luannaribeiro_lua@hotmail.com

2009-07-01

Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of {sup 60}Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD{sub 50} obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

International Nuclear Information System (INIS)

Cantinha, Rebeca S.; Nakano, Eliana; Silva, Luanna R.S.

2009-01-01

Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of 60 Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD 50 obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

On-Line High Dose-rate Gamma Irradiation Test of the Profibus/DP module

Energy Technology Data Exchange (ETDEWEB)

Cho, Jai Wan; Choi, Young Soo; Kim, Chang Hoi; Koo, In Soo; Hong, Seok Boong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-05-15

The field bus data communication is considered for application in nuclear environments. The nuclear facilities, including nuclear power plants, high radioactivity waste disposals, reprocessing plants and thermonuclear fusion installations can benefit from the unique advantages of the field bus communication network for the smart field instruments and controls. A major problem which arises when dealing with one in these nuclear environments, in special circumstances such as the RCS (reactor coolant system) area, is the presence of high gamma-ray irradiation fields. Radioactive constraints for the DBA(design basis accident) qualification of the RTD transmitter installed in the inside of the RCS pump are typically on the order of 4kGy/h with total doses up to 10kGy. In order to use an industrial field bus communication network as an ad-hoc sensor data link in the vicinity of the RCS area of the nuclear power plant, the robust survivability of these system in such intense gamma-radiation fields therefore needs to be verified. We have conducted high dose-rate (up to 4kGy) gamma irradiation experiments on a profibus/DP communication module. In this paper we describe the evolution of its basic characteristics with high dose-rate gamma irradiation and shortly explain the observed phenomena.

Reaction of the hematopoietic system under long-term emotional stress developed after preliminary gamma-irradiation with low doses

International Nuclear Information System (INIS)

Moroz, B.B.; Deshevoj, Yu.B.; Lebedev, V.G.; Lyrshchikova, A.V.; Vorotnikova, T.V.

1997-01-01

In experiments on rats and mice it was shown that the preliminary protected gamma-irradiation with cumulative dose of 0.9 Gy (dose rate - 0.03 Gy/day) or single short-term gamma-irradiation with dose of 0.9 Gy (dose rate - 1.61 Gy/min) inhibited development of adaptive reactions and compensatory abilities of the hematopoietic system under long-term emotional stress

Two gamma dose evaluation methods for silicon semiconductor detector

International Nuclear Information System (INIS)

Chen Faguo; Jin Gen; Yang Yapeng; Xu Yuan

2011-01-01

Silicon PIN diodes have been widely used as personal and areal dosimeters because of their small volume, simplicity and real-time operation. However, because silicon is neither a tissue-equivalent nor an air-equivalent material, an intrinsic disadvantage for silicon dosimeters is that a significant over-response occurs at low-energy region, especially below 200 keV. Using a energy compensation filter to flatten the energy response is one method overcoming this disadvantage. But for dose compensation method, the estimated dose depends only on the number of the detector pulses. So a weight function method was introduced to evaluate gamma dose, which depends on pulse number as well as its amplitude. (authors)

Effects of low dose gamma radiation on the early growth of red pepper and the resistance to subsquent high dose of radiation

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Baek, M. H.; Kim, D. H.; Lee, Y. K. [KAERI, Taejon (Korea, Republic of); Lee, Y. B. [Chungnam National Univ., Taejon (Korea, Republic of)

2001-05-01

Red pepper (capsicum annuum L. cv. Jokwang and cv. Johong) seeds were irradiated with the dose of 0{approx}50 Gy to investigated the effect of the low dose gamma radiation on the early growth and resistance to subsequent high dose of radiation. The effect of the low dose gamma radiation on the early growth and resistance to subsequenct high dose of radiation were enhanced in Johong cultivar but not in Jokwang cultivar. Germination rate and early growth of Johong cultivar were noticeably increased at 4 Gy-, 8 Gy- and 20 Gy irradiation group. Resistance to subsequent high dose of radiation of Johong cultivar were increased at almost all of the low dose irradiation group. Especially it was highest at 4 Gy irradiation group. The carotenoid contents and enzyme activity on the resistance to subsequent high dose of radiation of Johong cultivar were increased at the 4 Gy and 8 Gy irradiation group.

Cosmic-ray contribution in measurement of environmental gamma-ray dose

International Nuclear Information System (INIS)

Nagaoka, Kazunori; Honda, Kouichirou; Miyano, Keiji

1996-01-01

Nowadays several kinds of dosimeters are being used for environmental gamma-ray monitoring. However the results measured by those instruments are not always in good agreement. It may be caused from the different characteristics of dosimeters. In particular the different responses of the instruments to cosmic-rays give significant influence on the results. Environmental radiation measurements at various altitudes on Mt. Fuji were carried out using a scintillation spectrometer with 3''φ spherical NaI(Tl), a pressurized ionization chamber (PIC), an air-equivalent ionization chamber (IC), thermoluminescence dosimeters (TLD), radiophotoluminescence glass dosimeters (RPLD) and NaI(Tl) scintillation survey meters so that the response characteristics of these instruments to cosmic-rays could be clarified. Cosmic-ray contributions for all instruments were correlated with counting rate over 3 MeV by the spectrometer. Each contribution can be estimated by measurement of the counting rate. Conversion factors (nGy/h/cpm) for IC, PIC, TLD, RPLD and NaI survey meters (TCS166 and TCS121C) were 0.33, 0.32, 0.25, 0.24, 0.06 and -0.01, respectively. Self-doses of these instruments were estimated by measurements at Nokogiriyama facilities of the Institute for Cosmic Ray Research, University of Tokyo. Self-doses for TLD and RPLD were approximately 6 nGy/h. The self dose effect should be taken into consideration in environmental dose measurements. These data are expected to be useful in estimating the cosmic-ray contribution and self-dose in the measurement of environmental gamma-ray dose. (author)

Gamma dose rate changes in buildings in the region of Southeastern Iran using thermoluminescence dosimetry

Energy Technology Data Exchange (ETDEWEB)

Jomehzadeh Mahani, A. [Hormozgan un Univ. of medical sciences, Paramedical School, Bandarabbas (Iran, Islamic Republic of); Bahreyni Toosi, M.T. [Mashhad Univ. of medical sciences, Medical school (Iran, Islamic Republic of)

2006-07-01

oduction: It is important to measure background radiation, because human beings are always exposed to environmental radiation. The terrestrial component of the natural background depends on the compositions of soils and rocks in which are contained. A significant contribution to total dose from natural sources comes from terrestrial radionuclides such as U- 238, Th- 232 and K- 40. The level of gamma dose rate in buildings depends on the climate / weather, ventilation of living environment, local geology, drainage patterns and other factors. The objective of this study was to establishing the distribution of environmental gamma dose rates in the type of building sampled included cement-sand and soil brick buildings. Materials and Methods: Equipments used in this study include: 1-TLD-100 H (LiF: Mg, Cu, P) dosimeters. 2- TLD-Reader 3500 made by Harshaw, USA. In order to determine indoor gamma dose rate, the dosimeters were calibrated at room temperature with Co-60 source. Before using the dosimeters to measure environmental dose they were subjected to the thermal treatment in a normal oven. Two TLDs, were embedded in a 5 mm PMMA mini-phantom to register only gamma ray. 20 buildings for this study chosen randomly throughout Kerman town, southeastern Iran. Inside each building a holder was hung at a height of above 3 m. The period of monitoring of TLDs was 15 days. The TLDs were retrieved from the buildings and taken to the Mashhad university of medical sciences where they were read with a Harshaw TLD reader model 3500. Results: Our results indicate that indoor gamma dose rate ranged from 106 n Sv/h to 133 n Sv/h for cement-sand buildings with an average of 114.72 n Sv/h. For soil buildings the indoor gamma dose rate varied from 86 n Sv/h to 116 n Sv/h with an average of 100.50 n Sv/h. While the average gamma drate in cement-sand buildings is highest (114.72 n Sv/h), that of soil buildings is lowest (100.50 n Sv/h). Discussion: Average values vary from building to

Dose distribution close to metal implants in Gamma Knife Radiosurgery: A Monte Carlo study

International Nuclear Information System (INIS)

Cheung, Joel Y.C.; Yu, K.N.; Chan, Josie F.K.; Ho, Robert T.K.; Yu, C.P.

2003-01-01

Materials with high atomic numbers favor the occurrence of the photoelectric effect when they are irradiated with gamma rays. Therefore, the photoelectric effects of metal implants within the target regions in Gamma Knife Radiosurgery are worth studying. In the present work, Monte Carlo simulations using EGS4 were employed to investigate the resulting dose enhancements. A dose enhancement as high as 10% was observed close to a platinum implant along the x and y axes, while no significant dose enhancements were observed for silver, stainless steel 301, and titanium ones. A dose enhancement as high as 20% was observed close to the platinum implant along the z axis at the superior position of the metal-phantom interface and was 10% higher for other metal implants

Effects of low dose gamma irradiation on PVC blood bags containing anticoagulant CPDA solution

International Nuclear Information System (INIS)

Mitra, D.; Varshney, Lalit; Arjun, Chanda

2006-01-01

PVC blood bags were exposed to 20Gy and 60Gy low gamma radiation dose to investigate possibility of change in leaching behavior of the plasticizer into CPDA solution and the blood. Reversed phase HPLC was used for the investigations on anti coagulant solution CPDA(citrate, phosphate, dextrose and adenine) contained in PVC bag before and after gamma irradiation. The studies were repeated using methanol as an extractant instead of CPDA solution, considering higher extractability of plasticizer by blood. Irradiation of PVC bags by gamma radiation for a dose up to 60Gy does not lead to change in leaching behavior of the plasticizer in CPDA solution and methanol indicating similar expected behavior in blood. (author)

Facility for gamma irradiations of cultured cells at low dose rates: design, physical characteristics and functioning

International Nuclear Information System (INIS)

Esposito, Giuseppe; Anello, Pasquale; Pecchia, Ilaria; Tabocchini, Maria Antonella; Campa, Alessandro

2016-01-01

We describe a low dose/dose rate gamma irradiation facility (called LIBIS) for in vitro biological systems, for the exposure, inside a CO_2 cell culture incubator, of cells at a dose rate ranging from few μGy/h to some tens of mGy/h. Three different "1"3"7Cs sources are used, depending on the desired dose rate. The sample is irradiated with a gamma ray beam with a dose rate uniformity of at least 92% and a percentage of primary 662 keV photons greater than 80%. LIBIS complies with high safety standards. - Highlights: • A gamma irradiation facility for chronic exposures of cells was set up at the Istituto Superiore di Sanità. • The dose rate uniformity and the percentage of primary 662 keV photons on the sample are greater than 92% and 80%, respectively. • The GEANT4 code was used to design the facility. • Good agreement between simulation and experimental dose rate measurements has been obtained. • The facility will allow to safely investigate different issues about low dose rate effects on cultured cells.

Statistical approaches to forecast gamma dose rates by using measurements from the atmosphere

International Nuclear Information System (INIS)

Jeong, H.J.; Hwang, W. T.; Kim, E.H.; Han, M.H.

2008-01-01

In this paper, the results obtained by inter-comparing several statistical techniques for estimating gamma dose rates, such as an exponential moving average model, a seasonal exponential smoothing model and an artificial neural networks model, are reported. Seven years of gamma dose rates data measured in Daejeon City, Korea, were divided into two parts to develop the models and validate the effectiveness of the generated predictions by the techniques mentioned above. Artificial neural networks model shows the best forecasting capability among the three statistical models. The reason why the artificial neural networks model provides a superior prediction to the other models would be its ability for a non-linear approximation. To replace the gamma dose rates when missing data for an environmental monitoring system occurs, the moving average model and the seasonal exponential smoothing model can be better because they are faster and easier for applicability than the artificial neural networks model. These kinds of statistical approaches will be helpful for a real-time control of radio emissions or for an environmental quality assessment. (authors)

Determination of dose factors for external gamma radiation in dwellings

International Nuclear Information System (INIS)

Maduar, M.F.; Hiromoto, G.

2000-01-01

A significant contribution to the global population exposure to ionizing radiation arises from natural sources, especially from radionuclides present in terrestrial crust. Human activities can eventually increase that exposure to significant levels, from the point of view of radiological protection. The presence of natural radionuclides in building materials may lead to an increment of both external and internal radiation exposure of the population. External exposure in dwellings arises from gamma-emitter radionuclides existing in the walls, floor and ceiling of their rooms. Mathematical models can be used to predict external dose rates inside the room, known the radionuclide concentration activities in dwelling constituents. This paper presents a methodology for theoretical evaluation of external gamma doses due to radionuclides present in the walls of an hypothetical standard room. The room is modeled as three pairs of rectangular sheets with finite thickness. Assessment of doses was performed through the application of photon transport model, taking in account self-absorption and radiation buildup. As the external dose due to a particular radionuclide is proportional to its activity concentration, results are presented as dose factors, defined as a ratio of absorbed dose (nGy.h -1 ) to the activity concentration (Bq.kg -1 ), for each radionuclide. The radionuclides were assumed to be uniformly distributed in the building materials. Calculations were performed for concrete walls and results are presented for 40 K, 226 Ra, and 232 Th, taking in account, for dose calculations, all gamma emitters from 226 Ra and 232 Th decay chains. Sensitivity of the model was estimated by varying four of its input parameters within a reasonable range of applicability, while leaving all other parameters at fixed selected values. The parameters studied and respective ranges of variation were: for thickness, 5 to 60 cm; for density, 0.5 to 4 g.cm -3 ; for the room length, 1.5 to 10 m

Environmental radiation monitoring: mobile gamma dose rate measurements along Mumbai-Hyderabad rail route and Hyderabad city roads

International Nuclear Information System (INIS)

Divkar, J.K.; Padmanabhan, N.; Chaudhury, Probal; Pradeepkumar, K.S.; Pujari, R.N.; Dogra, Santosh; Sharma, D.N.; Rajagopalan, S.; Srivastava, G.K.

2005-01-01

Environmental Radiation monitoring based on gamma dose rate logging on a mobile platform integrated with real time position from a Global Positioning System is an effective tool to acquire dose rate profile and generate radiological map of any geographical region. The microcontroller based dose rate data acquisition system capable of storing the acquired data and transferring to an attached laptop/PC and providing a graphical illustration of relative variations in gamma background can also be used for quick assessment of environmental radiological impact assessment. This paper describes the methodology and results of the environmental gamma dose rate monitoring surveys carried out: (i) on Mumbai-Hyderabad rail route with the systems installed in the trains guard's room and (ii) Hyderabad city roads with systems installed in a monitoring van. The results indicate significant difference in the gamma background measured along the rail route between Mumbai-Hyderabad and in the radiological map generated after the Hyderabad city survey. (author)

Effect of gamma irradiation dose on the fabrication of α-elastin nanoparticles by gamma-ray crosslinking

International Nuclear Information System (INIS)

Fujimoto, Mari; Takeda, Mayuko; Okamoto, Kouji; Furuta, Masakazu

2011-01-01

Nanoparticles were prepared utilizing the thermosensitive aggregation of α-elastin and gamma-ray crosslinking. We investigated the effect of the α-elastin irradiation doses to verify the yield of crosslinked nanoparticles. Aqueous solution of α-elastin (10 mg/ml) was used for the aggregation on raising temperature above its cloudy point (CP), followed by gamma-ray crosslinking. A slow heating process (1.9 o C/min) effectively led to aggregation of polypeptide and irradiation with more than 15 kGy yielded stable crosslinked nanoparticles with diameters less than ca. 200 nm and a narrow size distribution.

Effect of gamma irradiation dose on the fabrication of {alpha}-elastin nanoparticles by gamma-ray crosslinking

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, Mari; Takeda, Mayuko [Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570 (Japan); Okamoto, Kouji [Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka 820-8502 (Japan); Furuta, Masakazu, E-mail: mfuruta@b.s.osakafu-u.ac.j [Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570 (Japan)

2011-02-15

Nanoparticles were prepared utilizing the thermosensitive aggregation of {alpha}-elastin and gamma-ray crosslinking. We investigated the effect of the {alpha}-elastin irradiation doses to verify the yield of crosslinked nanoparticles. Aqueous solution of {alpha}-elastin (10 mg/ml) was used for the aggregation on raising temperature above its cloudy point (CP), followed by gamma-ray crosslinking. A slow heating process (1.9 {sup o}C/min) effectively led to aggregation of polypeptide and irradiation with more than 15 kGy yielded stable crosslinked nanoparticles with diameters less than ca. 200 nm and a narrow size distribution.

Calculation of dose conversion factors for doses in the fingernails to organ doses at external gamma irradiation in air

International Nuclear Information System (INIS)

Khailov, A.M.; Ivannikov, A.I.; Skvortsov, V.G.; Stepanenko, V.F.; Orlenko, S.P.; Flood, A.B.; Williams, B.B.; Swartz, H.M.

2015-01-01

Absorbed doses to fingernails and organs were calculated for a set of homogenous external gamma-ray irradiation geometries in air. The doses were obtained by stochastic modeling of the ionizing particle transport (Monte Carlo method) for a mathematical human phantom with arms and hands placed loosely along the sides of the body. The resulting dose conversion factors for absorbed doses in fingernails can be used to assess the dose distribution and magnitude in practical dose reconstruction problems. For purposes of estimating dose in a large population exposed to radiation in order to triage people for treatment of acute radiation syndrome, the calculated data for a range of energies having a width of from 0.05 to 3.5 MeV were used to convert absorbed doses in fingernails to corresponding doses in organs and the whole body as well as the effective dose. Doses were assessed based on assumed rates of radioactive fallout at different time periods following a nuclear explosion. - Highlights: • Elemental composition and density of nails were determined. • MIRD-type mathematical human phantom with arms and hands was created. • Organ doses and doses to nails were calculated for external photon exposure in air. • Effective dose and nail doses values are close for rotational and soil surface exposures.

Prediction of terrestrial gamma dose rate based on geological formations and soil types in the Johor State, Malaysia.

Science.gov (United States)

Saleh, Muneer Aziz; Ramli, Ahmad Termizi; bin Hamzah, Khaidzir; Alajerami, Yasser; Moharib, Mohammed; Saeed, Ismael

2015-10-01

This study aims to predict and estimate unmeasured terrestrial gamma dose rate (TGDR) using statistical analysis methods to derive a model from the actual measurement based on geological formation and soil type. The measurements of TGDR were conducted in the state of Johor with a total of 3873 measured points which covered all geological formations, soil types and districts. The measurements were taken 1 m above the soil surface using NaI [Ti] detector. The measured gamma dose rates ranged from 9 nGy h(-1) to 1237 nGy h(-1) with a mean value of 151 nGy h(-1). The data have been normalized to fit a normal distribution. Tests of significance were conducted among all geological formations and soil types, using the unbalanced one way ANOVA. The results indicated strong significant differences due to the different geological formations and soil types present in Johor State. Pearson Correlation was used to measure the relations between gamma dose rate based on geological formation and soil type (D(G,S)) with the gamma dose rate based on geological formation (D(G)) or soil type (D(s)). A very good correlation was found between D(G,S) and D(G) or D(G,S) and D(s). A total of 118 pairs of geological formations and soil types were used to derive the statistical contribution of geological formations and soil types to gamma dose rates. The contribution of the gamma dose rate from geological formation and soil type were found to be 0.594 and 0.399, respectively. The null hypotheses were accepted for 83% of examined data, therefore, the model could be used to predict gamma dose rates based on geological formation and soil type information. Copyright © 2015 Elsevier Ltd. All rights reserved.

A study on the effect of low doses gamma radiation on mushroom spawn

International Nuclear Information System (INIS)

Ajlouni, Said

1993-03-01

Mushroom spawn (Hybrid-521) was irradiated at room temperature using low doses of gamma radiation (50-600 rad). The spawn was then planted at two stages; first, after 24 hours of irradiation, and second after storage for three weeks at refrigeration temperature. Results of this study showed that the applied doses of gamma radiation did not have any stimulatory effect on mushroom growth or productivity. It was also noticed that mushroom production rate decreased when irradiated spawn was stored for three weeks prior to planting, as compared with spawn planted 24 hours after irradiation. (author). 18 refs., 2 figs., 2 tabs

An energy-independent dose rate meter for beta and gamma radiation

International Nuclear Information System (INIS)

Heinzelmann, M.; Keller, M.

1986-01-01

An easy to handle dose rate meter has been developed at the Juelich Nuclear Research Centre with a small probe for the energy-independent determination of the dose rate in mixed radiation fields. The dose rate meter contains a small ionisation chamber with a volume of 15.5 cm 3 . The window of the ionisation chamber consists of an aluminised plastic foil of 7 mg.cm -2 . The dose rate meter is suitable for determining the dose rate in skin. With a supplementary depth dose cap, the dose rate can be determined in tissue at a depth of 1 cm. The dose rate meter is energy-independent within +-20% for 147 Pm, 204 Tl and 90 Sr/ 90 Y beta radiation and for gamma radiation in the energy range above 35 keV. (author)

SU-E-T-647: Quality Assurance of VMAT by Gamma Analysis Dependence On Low-Dose Threshold

International Nuclear Information System (INIS)

Song, J; Kim, M; Lee, S; Lee, M; Suh, T; Park, S

2015-01-01

Purpose: The AAPM TG-119 instructed institutions to use low-dose threshold (LDT) of 10% or a ROI determined by the jaw when they collected gamma analysis QA data of planar dose distribution. Also, based on a survey by Nelms and Simon, more than 70% of institutions use a LDT between 0% and 10% for gamma analysis. However, there are no clinical data to quantitatively demonstrate the impact of the LDT on the gamma index. Therefore, we performed a gamma analysis with LDTs of 0% to 15% according to both global and local normalization and different acceptance criteria: 3%/3 mm, 2%/2 mm, and 1%/1 mm. Methods: A total of 30 treatment plans—10 head and neck, 10 brain, and 10 prostate cancer cases—were randomly selected from the Varian Eclipse TPS, retrospectively. For the gamma analysis, a predicted portal image was acquired through a portal dose calculation algorithm in the Eclipse TPS, and a measured portal image was obtained using a Varian Clinac iX and an EPID. Then, the gamma analysis was performed using the Portal Dosimetry software. Results: For the global normalization, the gamma passing rate (%GP) decreased as the LDT increased, and all cases of low-dose thresholds exhibited a %GP above 95% for both the 3%/3 mm and 2%/2 mm criteria. However, for local normalization, the %GP increased as LDT increased. The gamma passing rate with LDT of 10% increased by 6.86%, 9.22% and 6.14% compared with the 0% in the case of the head and neck, brain and prostate for 3%/3 mm criteria, respectively. Conclusion: Applying the LDT in the global normalization does not have critical impact to judge patient-specific QA results. However, LDT for the local normalization should be carefully selected because applying the LDT could affect the average of the %GP to increase rapidly

SU-E-T-647: Quality Assurance of VMAT by Gamma Analysis Dependence On Low-Dose Threshold

Energy Technology Data Exchange (ETDEWEB)

Song, J; Kim, M; Lee, S; Lee, M; Suh, T [Department of Biomedical Engineering, Reasearch Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Park, S [Department of Biomedical Engineering, Reasearch Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Department of Radiation Oncology, Uijeongbu St. Mary’s Hospital, Gyeonggi-do (Korea, Republic of)

2015-06-15

Purpose: The AAPM TG-119 instructed institutions to use low-dose threshold (LDT) of 10% or a ROI determined by the jaw when they collected gamma analysis QA data of planar dose distribution. Also, based on a survey by Nelms and Simon, more than 70% of institutions use a LDT between 0% and 10% for gamma analysis. However, there are no clinical data to quantitatively demonstrate the impact of the LDT on the gamma index. Therefore, we performed a gamma analysis with LDTs of 0% to 15% according to both global and local normalization and different acceptance criteria: 3%/3 mm, 2%/2 mm, and 1%/1 mm. Methods: A total of 30 treatment plans—10 head and neck, 10 brain, and 10 prostate cancer cases—were randomly selected from the Varian Eclipse TPS, retrospectively. For the gamma analysis, a predicted portal image was acquired through a portal dose calculation algorithm in the Eclipse TPS, and a measured portal image was obtained using a Varian Clinac iX and an EPID. Then, the gamma analysis was performed using the Portal Dosimetry software. Results: For the global normalization, the gamma passing rate (%GP) decreased as the LDT increased, and all cases of low-dose thresholds exhibited a %GP above 95% for both the 3%/3 mm and 2%/2 mm criteria. However, for local normalization, the %GP increased as LDT increased. The gamma passing rate with LDT of 10% increased by 6.86%, 9.22% and 6.14% compared with the 0% in the case of the head and neck, brain and prostate for 3%/3 mm criteria, respectively. Conclusion: Applying the LDT in the global normalization does not have critical impact to judge patient-specific QA results. However, LDT for the local normalization should be carefully selected because applying the LDT could affect the average of the %GP to increase rapidly.

Isodose distributions and dose uniformity in the Portuguese gamma irradiation facility calculated using the MCNP code

CERN Document Server

Oliveira, C

2001-01-01

A systematic study of isodose distributions and dose uniformity in sample carriers of the Portuguese Gamma Irradiation Facility was carried out using the MCNP code. The absorbed dose rate, gamma flux per energy interval and average gamma energy were calculated. For comparison purposes, boxes filled with air and 'dummy' boxes loaded with layers of folded and crumpled newspapers to achieve a given value of density were used. The magnitude of various contributions to the total photon spectra, including source-dependent factors, irradiator structures, sample material and other origins were also calculated.

High dose effect of gamma and neutrons on the N-JFET electronic components

International Nuclear Information System (INIS)

Assaf, Jamal-Eddin

2006-11-01

Two types of N-JFET components have been irradiated by high doses of thermal neutrons and gamma rays up to 2000x10 12 n/cm 2 and 1000 kGy, respectively. The static tests show a decrease of the g m and I d s parameters. The behaviour of electronic noise on the output was the principal dynamic test after irradiation. The result of this test gives an increase of the noise with radiation dose increasing. The noise was described as the Equivalent Noise of Charge (ENC) at the output of the measurements set-up. The quantities and the qualities of the noise depend on the N-JEET type and the type of radiation (neutrons or gamma). Other tests were carried out like the relaxation or recovery phenomena after radiation, and the superposed effects of gamma and neutrons.(author)

Anomalous dose rate effects in gamma irradiated SiGe heterojunction bipolar transistors

International Nuclear Information System (INIS)

Banerjee, G.; Niu, G.; Cressler, J.D.; Clark, S.D.; Palmer, M.J.; Ahlgren, D.C.

1999-01-01

Low dose rate (LDR) cobalt-60 (0.1 rad(Si)/s) gamma irradiated Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) were studied. Comparisons were made with devices irradiated with 300 rad(Si)/s gamma radiation to verify if LDR radiation is a serious radiation hardness assurance (RHA) issue. Almost no LDR degradation was observed in this technology up to 50 krad(Si). The assumption of the presence of two competing mechanisms is justified by experimental results. At low total dose (le20 krad), an anomalous base current decrease was observed which is attributed to self-annealing of deep-level traps to shallower levels. An increase in base current at larger total doses is attributed to radiation induced generation-recombination (G/R) center generation. Experiments on gate-assisted lateral PNP transistors and 2D numerical simulations using MEDICI were used to confirm these assertions

Dose rate distribution of the GammaBeam: 127 irradiator using MCNPX code

International Nuclear Information System (INIS)

Gual, Maritza Rodriguez; Batista, Adriana de Souza Medeiros; Pereira, Claubia; Faria, Luiz O. de; Grossi, Pablo Andrade

2013-01-01

The GammaBeam - 127 Irradiator is widely used for biological, chemical and medical applications of the gamma irradiation technology using Cobalt 60 radioactive at the Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil. The source has maximum activity of 60.000Ci, which is composed by 16 double encapsulated radioactive pencils placed in a rack. The facility is classified by the IAEA as Category II (dry storage facility). The aim of this work is to present a modelling developed to evaluate the dose rates at the irradiation room and the dose distribution at the irradiated products. In addition, the simulations could be used as a predictive tool of dose evaluation in the irradiation facility helping benchmark experiments in new similar facilities. The MCNPX simulated results were compared and validated with radiometric measurements using Fricke and TLDs dosimeters along several positions inside the irradiation room. (author)

Effect of Low Gamma Irradiation Doses on Growth and Productivity of Green Bean

International Nuclear Information System (INIS)

Mohamed, A.M.M.F.

2011-01-01

The field experiment was conducted within the two successive growing seasons of 2007/2008 and 2008/2009 to study the effect of low gamma irradiation doses (0, 10, 20, 30, 40, 50 and 60 Gy) on growth and productivity of green bean cv. Bronco with 3 sowing dates 8, 18 and 28th of October in the first season and 30th of September, 10 and 20th of October in the second season. The results of laboratory determinations showed that gamma irradiation doses did not affect the germination percent but slightly affected germination rate and electrical conductivity. Concerning field experiment, data revealed that green bean plant vegetative growth, i.e., plant height, fresh and dry weight, leaf number and leaf area, at 45 days after planting (DAP) and shoot number at 30, 45 DAP recorded significantly the highest values at the first sowing date in both seasons. With respect of gamma irradiation doses, all the previously mentioned parameters of plant vegetative growth recorded the highest values with 40 Gy at 15, 30, and 45 DAP except number of leaves which recorded the highest value with 30 Gy at 15, 30 and 45 DAP. Concerning shoot number there was no significant difference among several doses at 30 DAP in the first season but in the second season it was 20 Gy and at 45 DAP compared with the control. Also the first sowing date in both seasons gave the highest pod length, fresh and dry weight, plant yield, number of pods per plant, marketable yield per plot and total yield per feddan. Whereas ,the second sowing date led to the lowest pod thickness. In addition, 20 Gy of gamma irradiation doses recorded the highest value of pod length .The 30 Gy dose showed the highest value of pod fresh and dry weight, plant yield and total yield per feddan. In addition ,the 20 and 30 Gy doses led to the highest pod number per plant and marketable yield, concerning pod thickness there was slight difference only in the second season between several doses. The second sowing date in the first season

Gamma-irradiated onions as a biological indicator of radiation dose

International Nuclear Information System (INIS)

Vaijapurkar, S.G.; Agarwal, Deepshikha; Chaudhuri, S.K.; Ram Senwar, Kana; Bhatnagar, P.K.

2001-01-01

Post-irradiation identification and dose estimation are required to assess the radiation-induced effects on living things in any nuclear emergency. In this study, radiation-induced morphological/cytological changes i.e., number of root formation and its length, shooting length, reduction in mitotic index, micronuclei formation and chromosomal aberrations in the root tip cells of gamma-irradiated onions at lower doses (50-2000 cGy) are reported. The capabilities of this biological species to store the radiation-induced information are also studied

Dose Response for Monokaryon mycelium of Pleurotus pulmonarius After Acute Gamma Radiation

International Nuclear Information System (INIS)

Wan Safina Wan Abdul Razak; Azhar Mohamad; Nie, H.J.

2016-01-01

Pleurotus pulmonarius is locally known as Grey oyster. The species is popular and widely cultivated throughout the world mostly in Asia Europe as their simple and low cost production technology and higher biological efficiency. Mutation induction is an alternative ways for improving available commercial strain for better quality traits. Dose response is important in evaluating effects of mutagenesis via acute gamma radiation. Monokaryon mycelium of Pleurotus pulmonarius was exposed to acute gamma radiation ranged from 0 Gy, 0.1 kGy, 0.2 kGy, 0.3 kGy, 0.4 kGy, 0.5 kGy, 0.6 kGy, 0.7 kGy, 0.8 kGy, 0.9 kGy, 1.0 kGy, 1.5 Gy, 2.0 kGy, 3.0 kGy and 4.0 kGy at dose rate 0.013 kGy/ min. growth performance was measured at 2 days interval to get the LD_5_0. Increasing of the irradiation dose found to decrease the growth performance of the monokaryon mycelium. LD_5_0 was revealed at 1.56 kGy for mono karyon mycelium. Discoveries of the works are important for the improvement of Pleurotus species via acute gamma radiation and benefiting to growers and mushroom industries. (author)

Aspartame tablets-gamma dose response and usability for routine radiation processing dosimetry using spectrophotometry

Energy Technology Data Exchange (ETDEWEB)

Shinde, S.H. [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: shs_barc@yahoo.com; Mukherjee, T. [Radiation Safety Systems Division, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2007-02-15

Aspartame tablets were studied for gamma dose response, using spectrophotometric read-out method. The optimum concentration for ferrous ions was 2x10{sup -4}moldm{sup -3} and xylenol orange with 2.5x10{sup -1}moldm{sup -3} of sulphuric acid for the optimum acidity in FX solution. Wavelength of maximum absorbance is 548nm. Post-irradiation stability is appreciable i.e. for not less than one month. Dose response is non-linear with third order polynomial fit, in the dose range of 1000-10000Gy. This system of aspartame was further used for carrying out relative percentage dose profile measurement in Gamma Cell-220. Results obtained were inter-compared with that of a glutamine dosimeter, which showed that maximum difference between the values of aspartame and glutamine systems is within +/-10%.

Aspartame tablets-gamma dose response and usability for routine radiation processing dosimetry using spectrophotometry

International Nuclear Information System (INIS)

Shinde, S.H.; Mukherjee, T.

2007-01-01

Aspartame tablets were studied for gamma dose response, using spectrophotometric read-out method. The optimum concentration for ferrous ions was 2x10 -4 moldm -3 and xylenol orange with 2.5x10 -1 moldm -3 of sulphuric acid for the optimum acidity in FX solution. Wavelength of maximum absorbance is 548nm. Post-irradiation stability is appreciable i.e. for not less than one month. Dose response is non-linear with third order polynomial fit, in the dose range of 1000-10000Gy. This system of aspartame was further used for carrying out relative percentage dose profile measurement in Gamma Cell-220. Results obtained were inter-compared with that of a glutamine dosimeter, which showed that maximum difference between the values of aspartame and glutamine systems is within +/-10%

On-Line High Dose-Rate Gamma Ray Irradiation Test of the CCD/CMOS Cameras

Energy Technology Data Exchange (ETDEWEB)

Cho, Jai Wan; Jeong, Kyung Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

In this paper, test results of gamma ray irradiation to CCD/CMOS cameras are described. From the CAMS (containment atmospheric monitoring system) data of Fukushima Dai-ichi nuclear power plant station, we found out that the gamma ray dose-rate when the hydrogen explosion occurred in nuclear reactors 1{approx}3 is about 160 Gy/h. If assumed that the emergency response robot for the management of severe accident of the nuclear power plant has been sent into the reactor area to grasp the inside situation of reactor building and to take precautionary measures against releasing radioactive materials, the CCD/CMOS cameras, which are loaded with the robot, serve as eye of the emergency response robot. In the case of the Japanese Quince robot system, which was sent to carry out investigating the unit 2 reactor building refueling floor situation, 7 CCD/CMOS cameras are used. 2 CCD cameras of Quince robot are used for the forward and backward monitoring of the surroundings during navigation. And 2 CCD (or CMOS) cameras are used for monitoring the status of front-end and back-end motion mechanics such as flippers and crawlers. A CCD camera with wide field of view optics is used for monitoring the status of the communication (VDSL) cable reel. And another 2 CCD cameras are assigned for reading the indication value of the radiation dosimeter and the instrument. In the preceding assumptions, a major problem which arises when dealing with CCD/CMOS cameras in the severe accident situations of the nuclear power plant is the presence of high dose-rate gamma irradiation fields. In the case of the DBA (design basis accident) situations of the nuclear power plant, in order to use a CCD/CMOS camera as an ad-hoc monitoring unit in the vicinity of high radioactivity structures and components of the nuclear reactor area, a robust survivability of this camera in such intense gamma-radiation fields therefore should be verified. The CCD/CMOS cameras of various types were gamma irradiated at a

Improved estimates of external gamma dose rates in the environs of Hinkley Point Power Station

International Nuclear Information System (INIS)

Macdonald, H.F.; Thompson, I.M.G.

1988-07-01

The dominant source of external gamma dose rates at centres of population within a few kilometres of Hinkley Point Power Station is the routine discharge of 41-Ar from the 'A' station magnox reactors. Earlier estimates of the 41-Ar radiation dose rates were based upon measured discharge rates, combined with calculations using standard plume dispersion and cloud-gamma integration models. This report presents improved dose estimates derived from environmental gamma dose rate measurements made at distances up to about 1 km from the site, thus minimising the degree of extrapolation introduced in estimating dose rates at locations up to a few kilometres from the site. In addition, results from associated chemical tracer measurements and wind tunnel simulations covering distances up to about 4 km from the station are outlined. These provide information on the spatial distribution of the 41-Ar plume during the initial stages of its dispersion, including effects due to plume buoyancy and momentum and behaviour under light wind conditions. In addition to supporting the methodology used for the 41-Ar dose calculations, this information is also of generic interest in the treatment of a range of operational and accidental releases from nuclear power station sites and will assist in the development and validation of existing environmental models. (author)

Effect of gamma irradiation at doses of 5-15 kGy on the quality properties of durum wheat semolina

International Nuclear Information System (INIS)

Taha, S.A.

1990-01-01

Semolina purified from four durum wheat varieties were gamma-irradiated with doses of 0, 5, 10 and 15 kGy, i.e., dose levels expected to improve the colour of pasta products, suitable for reduction of microbial contamination, and high doses required for insect disinfestation. The irradiation resulted in significant losses in carotenoid content and oxidative enzyme activities. Gamma irradiation slightly affected the mixing properties, greatly reduced the gluten strength and adversely affected firmness of cooked pasta. Consequently, preservative gamma irradiation of durum wheat semolina should be limited to a maximum dose of 5 kGy. (author) 39 refs.; 3 tabs

Estimate on external effective doses received by the Iranian population from environmental gamma radiation sources

Energy Technology Data Exchange (ETDEWEB)

Roozitalab, J.; Reza deevband, M.; Rastkhah, N. [National Radiation Protection Dept. Atomic Energy Organization (Iran, Islamic Republic of); Sohrabi, M. [Intenatinal atomic Energy Agency, Vienna (Austria)

2006-07-01

Concentration of natural radioactive materials, especially available U 238, Ra 226, Th 232, and K 40 in construction materials and soil, as well as absorb dose from cosmic rays, is the most important source of the people for effective doses from the environment radiation. In order to evaluate external effective dose, it has been carried out more than 1000 measurements in 36 cities by sensitive dosimeters to environmental gamma radiation for indoor and outdoor conditions in residential areas; which its results show that range of gamma exposure for inside of buildings in Iran is 8.7-20.5 {mu}R/h, and outdoor environments of different cities is 7.9-20.6 {mu}R/h, which their mean value are 14.33 and 12.62 {mu}R/h respectively. Meanwhile, it has been estimated that beam-absorbing ratio between indoor and outdoor in measured environments is 1.55, except contribution of cosmic rays. This studies show that average effective dose for each Iranian person from environmental gamma is 96.9 n Sv/h, and annually effective dose for every person is 0.848 mSv. (authors)

Estimate on external effective doses received by the Iranian population from environmental gamma radiation sources

International Nuclear Information System (INIS)

Roozitalab, J.; Reza deevband, M.; Rastkhah, N.; Sohrabi, M.

2006-01-01

Concentration of natural radioactive materials, especially available U 238, Ra 226, Th 232, and K 40 in construction materials and soil, as well as absorb dose from cosmic rays, is the most important source of the people for effective doses from the environment radiation. In order to evaluate external effective dose, it has been carried out more than 1000 measurements in 36 cities by sensitive dosimeters to environmental gamma radiation for indoor and outdoor conditions in residential areas; which its results show that range of gamma exposure for inside of buildings in Iran is 8.7-20.5 μR/h, and outdoor environments of different cities is 7.9-20.6 μR/h, which their mean value are 14.33 and 12.62 μR/h respectively. Meanwhile, it has been estimated that beam-absorbing ratio between indoor and outdoor in measured environments is 1.55, except contribution of cosmic rays. This studies show that average effective dose for each Iranian person from environmental gamma is 96.9 n Sv/h, and annually effective dose for every person is 0.848 mSv. (authors)

Responses of rat R-1 cells to low dose rate gamma radiation and multiple daily dose fractions

International Nuclear Information System (INIS)

Kal, H.B.; Bijman, J.Th.

1981-01-01

Multifraction irradiation may offer the same therapeutic gain as continuous irradiation. Therefore, a comparison of the efficacy of low dose rate irradiation and multifraction irradiation was the main objective of the experiments to be described. Both regimens were tested on rat rhabdomyosarcoma (R-1) cells in vitro and in vivo. Exponentially growing R-1 cells were treated in vitro by a multifraction irradiation procedure with dose fractions of 2 Gy gamma radiation and time intervals of 1 to 3 h. The dose rate was 1.3 Gy.min -1 . The results indicate that multifractionation of the total dose is more effective with respect to cell inactivation than continuous irradiation. (Auth.)

Repeat Gamma-Knife Radiosurgery for Refractory or Recurrent Trigeminal Neuralgia with Consideration About the Optimal Second Dose.

Science.gov (United States)

Park, Seong-Cheol; Kwon, Do Hoon; Lee, Do Hee; Lee, Jung Kyo

2016-02-01

To investigate adequate radiation doses for repeat Gamma Knife radiosurgery (GKS) for trigeminal neuralgia in our series and meta-analysis. Fourteen patients treated by ipsilateral repeat GKS for trigeminal neuralgia were included. Median age of patients was 65 years (range, 28-78), the median target dose, 140-180). Patients were followed a median of 10.8 months (range, 1-151) after the second gamma-knife surgery. Brainstem dose analysis and vote-counting meta-analysis of 19 studies were performed. After the second gamma-knife radiosurgeries, pain was relieved effectively in 12 patients (86%; Barrow Neurological Institute Pain Intensity Score I-III). Post-gamma-knife radiosurgery trigeminal nerve deficits were mild in 5 patients. No serious anesthesia dolorosa was occurred. The second GKS radiation dose ≤ 60 Gy was significantly associated with worse pain control outcome (P = 0.018 in our series, permutation analysis of variance, and P = 0.009 in the meta-analysis, 2-tailed Fisher's exact test). Cumulative dose ≤ 140-150 Gy was significantly associated with poor pain control outcome (P = 0.033 in our series and P = 0.013 in the meta-analysis, 2-tailed Fisher's exact test). A cumulative brainstem edge dose >12 Gy tended to be associated with trigeminal nerve deficit (P = 0.077). Our study suggests that the second GKS dose is a potentially important factor. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of sub-sterilizing doses of gamma radiation on Spodoptera frugiperda (Smith) pupae

International Nuclear Information System (INIS)

Duarte Aguilar, J.A.; Arthur, Valter

1998-01-01

Studies were undertaken to verify the effects of sub-sterilizing doses of gamma radiations on pupae of Spodoptera frugiperda (Smith) and transfer of genetic heredity on the first and second generations. Statistical analysis showed difference in the ageing effect of gamma radiations on the larval phase and larval viability ranged between 72 and 94 percent, when irradiated (50 Gy) males or females were crossed with non-irradiated adults. With doses of 100, 125, 150 and 175 Gy the crossing of irradiated males x non irradiated females the larval viability was between 64 and 94 per cent in F-1 and F-2 generations. The duration and other life parameters of the pupae and adults did not differ from the controls. The egg laying ability was not affected by doses up to 150 Gy on both the sexes. If irradiated females with doses of 175 and 200 Gy were crossed with non-irradiated males, the egg laying was inhibited when males were irradiated with one of these doses, the offspring females did not lay eggs or laid non-fertile eggs. (author)

A novel time dependent gamma evaluation function for dynamic 2D and 3D dose distributions

International Nuclear Information System (INIS)

Podesta, Mark; Persoon, Lucas CGG; Verhaegen, Frank

2014-01-01

Modern external beam radiotherapy requires detailed verification and quality assurance so that confidence can be placed on both the delivery of a single treatment fraction and on the consistency of delivery throughout the treatment course. To verify dose distributions, a comparison between prediction and measurement must be made. Comparisons between two dose distributions are commonly performed using a Gamma evaluation which is a calculation of two quantities on a pixel by pixel basis; the dose difference, and the distance to agreement. By providing acceptance criteria (e.g. 3%, 3 mm), the function will find the most appropriate match within its two degrees of freedom. For complex dynamic treatments such as IMRT or VMAT it is important to verify the dose delivery in a time dependent manner and so a gamma evaluation that includes a degree of freedom in the time domain via a third parameter, time to agreement, is presented here. A C++ (mex) based gamma function was created that could be run on either CPU and GPU computing platforms that would allow a degree of freedom in the time domain. Simple test cases were created in both 2D and 3D comprising of simple geometrical shapes with well-defined boundaries varying over time. Changes of varying magnitude in either space or time were introduced and repeated gamma analyses were performed varying the criteria. A clinical VMAT case was also included, artificial air bubbles of varying size were introduced to a patient geometry, along with shifts of varying magnitude in treatment time. For all test cases where errors in distance, dose or time were introduced, the time dependent gamma evaluation could accurately highlight the errors. The time dependent gamma function presented here allows time to be included as a degree of freedom in gamma evaluations. The function allows for 2D and 3D data sets which are varying over time to be compared using appropriate criteria without penalising minor offsets of subsequent radiation

Calibration curve to establish the exposure dose at Co60 gamma radiation

International Nuclear Information System (INIS)

Guerrero C, C.; Brena V, M.

2000-01-01

The biological dosimetry is an adequate method for the dose determination in cases of overexposure to ionizing radiation or doubt of the dose obtained by physical methods. It is based in the aberrations analysis produced in the chromosomes. The behavior of leisure in chromosomes is of dose-response type and it has been generated curves in distinct laboratories. Next is presented the curve for gamma radiation produced in the National Institute of Nuclear Research (ININ) laboratory. (Author)

Effect of Low Dose gamma-ray Irradiation on the Germination and Growth in Red Pepper (Capcicum annuum L.)

International Nuclear Information System (INIS)

Lee Eun-Kyung; Kim Jae-Sung

1998-01-01

This study was conducted to determine the effect of low dose gamma-ray irradiation in red pepper. The germination percentage, plant, the number of flower, chlorophyll contents, leaf length and width were observed from plants grown with red pepper seeds irradiated with various low dose of gamma-ray. The germination percentage of irradiation group treatmented gamma-ray was much higher than that of the control. Specially the germination percentage after sowing red pepper seeds on paper towel was higher than 1,000 and 2,000 rad irradiation group. The height of plants grown with red pepper seeds irradiated with gamma-ray was increased in 100, 200 and 400 rad irradiation group compared to that of the control. The height of plant from 2,400 rad irradiation group, however, was shorter than that of the control. Nutrient contents of leaves of plants grown with red pepper seeds irradiated with various dose of gamma-ray were significantly increased in 800 and 1,200 rad irradiation group. Electric conductivity (EC) of the water used for seed germination was lower irradiation group than control group. Therefore, there was the possibility to increase the germination and plant growth with gamma-ray of adequate low dose

Effect of low doses of gamma radiation on barley tolerance grown under saline conditions

International Nuclear Information System (INIS)

Charbaji, T.; Khalifa, Kh; Al-Ain, F.

2003-01-01

A field experiment was conducted at Al-Hijanah, an area located at about 35 km south east of Damascus. Seeds of two barley varieties [White Arabi (WA) and Pakistani 30163 (PK) were irradiated with 2 doses 0 and 15 Gy of gamma irradiation. Then, they were shown on salty soil (17.6-18,9 m mos/cm) and irrigated with salty water (5.12-5.75 m mos/cm). A dose of 15 Gy of gamma irradiation was shown to positively affect the percent germination of PK but had no similar effect on WA. The results were obtained at 3 different growth stages: first, the heading stage, 15 Gy dose increased shoots dry weight, Mg ++ , P content and percent of WA, whereas N percent of PK was decreased. When the seeds were irradiated by the same dose. K + content in WA was significantly higher than that in PK. Second, physiological maturity stage, the same dose (15 Gy) increased shoot dry, but affected negatively K + and Na + contents in PK variety. As for WA variety, Mg ++ and P contents were increased, whereas Na + and Cl - were slightly decreased. Third, harvest stage, gamma irradiation had a positive effect on total yield, grain yield, nitrogen yield and harvest index of PK variety. A positive effect was produced on straw yield, 1000-grain weight, and nitrogen yield of WA variety. (author)

Dose conformity of gamma knife radiosurgery and risk factors for complications

International Nuclear Information System (INIS)

Nakamura, Jean L.; Verhey, Lynn J.; Smith, Vernon; Petti, Paula L.; Lamborn, Kathleen R.; Larson, David A.; Wara, William M.; McDermott, Michael W.; Sneed, Penny K.

2001-01-01

Purpose: To quantitatively evaluate dose conformity achieved using Gamma Knife radiosurgery, compare results with those reported in the literature, and evaluate risk factors for complications. Methods and Materials: All lesions treated at our institution with Gamma Knife radiosurgery from May 1993 (when volume criteria were routinely recorded) through December 1998 were reviewed. Lesions were excluded from analysis for reasons listed below. Conformity index (the ratio of prescription volume to target volume) was calculated for all evaluable lesions and for lesions comparable to those reported in the literature on conformity of linac radiosurgery. Univariate Cox regression models were used to test for associations between treatment parameters and toxicity. Results: Of 1612 targets treated in 874 patients, 274 were excluded, most commonly for unavailability of individual prescription volume data because two or more lesions were included within the same dose matrix (176 lesions), intentional partial coverage for staged treatment of large arteriovenous malformations (AVMs) (33 lesions), and missing target volume data (26 lesions). The median conformity indices were 1.67 for all 1338 evaluable lesions and 1.40-1.43 for lesions comparable to two linac radiosurgery series that reported conformity indices of 1.8 and 2.7, respectively. Among all 651 patients evaluable for complications, there were one Grade 5, eight Grade 4, and 27 Grade 3 complications. Increased risk of toxicity was associated with larger target volume, maximum lesion diameter, prescription volume, or volume of nontarget tissue within the prescription volume. Conclusions: Gamma Knife radiosurgery achieves much more conformal dose distributions than those reported for conventional linac radiosurgery and somewhat more conformal dose distributions than sophisticated linac radiosurgery techniques. Larger target, nontarget, or prescription volumes are associated with increased risk of toxicity

Dose rate modelled for the outdoors of a gamma irradiation

International Nuclear Information System (INIS)

Mangussi, J

2012-01-01

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

The effect of low dose gamma irradiation on maize production (1985-1988)

International Nuclear Information System (INIS)

Al-Oudat, M.; Khalifa, K.

1990-06-01

Presowing seed irradiation has been reported as a useful application of radiation in agriculture to stimulate growth and increase the yield of certain field crops. To the best of our knowledge the feasibility of this treatment has not yet been tested on maize in Syria. Our experiments were carried out in controlled, in field conditions, and in a large scale application. Samples of air dried seeds of maize (Var. Gota-82 and LG-11) of previous season were irradiated by gamma-rays from a 137 Cs sourse using doses of 5, 7.5, 10, 15, 20, 30, 40 and 50 Gy. at dose rate of 9.8 - 9.2 Gy/min. Then were planted after 2 days from irradiation with unirradiated control, in complete randomized block design and replicated 4 times for four seasons (1985-1988). The date revealed that gamma irradiation, at interval doses of 5 - 10 Gy led to, first: Acceleration of seed germination, faster development, intensive development of root system, increase plant hieght (12 - 19%) and significant increase in ear size and number, and second: Increase both green mass (15 - 35%) and seed yield (10 - 31%), and percentage of seed protein (2 - 17%). Large scale applications were performed in 1987 and 1988 using a transportable irradiation unit POC-1 137 Cs and dose of 7.5 Gy. A significant yield increase was obtained from all fields. The average percentage increment varied from 13 - 30% which is approximately 382-765 Kg/h. Therefore, presowing seed irradiation with low doses gamma irradiation ranging from 5 to 10 Gy, was found to be feasible for application in qualitative and quantitative improvement of maize yield. (author). 38 refs., 12 figs., 44 tabs

Comparative response of dogs and monkeys to sublethal acute and continuous low dose-rate gamma-ray exposure

International Nuclear Information System (INIS)

Spalding, J.F.; Holland, L.M.; Johnson, O.S.; LaBauve, P.M.; London, J.E.; Prine, J.R.; Vigil, E.A.

1977-02-01

Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (injury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with 35 R/day until death to determine the amount of radiation-induced injury remaining in conditioned animals as a reduction in mean survival time. Dogs (50 percent) and monkeys (8 percent) died from injury incurred during the conditioning exposures. Thus, the comparative response of dogs and monkeys to dose protraction by acute dose fractionation was similar to what might be expected from a single acute dose. Mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approximately 1400 h). Thus, hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35 R/day gamma-ray challenge exposure were greater than for their control counterparts. Thus, the long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than four times the acute LD 50 - 30 in dogs and approximately two times that of monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 R/day

Cytosolic Hsp70/Hsc70 protein expression in lymphocytes exposed to low gamma-ray dose

International Nuclear Information System (INIS)

Manzanares A, E.; Vega C, H.R.; Letechipia de Leon, C.; Guzman E, L.J.; Garcia T, M.

2004-01-01

The purpose of this study was to evaluate the effect of low gamma ray intensity upon Hsp70 expression in human Iymphocytes. The heat shock proteins (Hsp) family, are a group of proteins present in all living organism, therefore there are highly conserved and are related to adaptation and evolution. At cellular level these proteins acts as chaperones correcting denatured proteins. When a stress agent, such heavy metals, UV, heat, etc. is affecting a cell a response to this aggression is triggered only through over expression of Hsp. Several studies has been carried out in which the cellular effect are observed, mostly of these studies uses large doses, but very few studies are related with low doses. Blood of healthy volunteers was obtained and the Iymphocytes were isolated by ficoll- histopaque gradient. Experimental lots were irradiated in a 137 Cs gamma-ray. Hsp70 expression was found since 0.5 c Gy, indicating a threshold to very low doses of gamma rays. (Author)

Cytosolic Hsp70/Hsc70 protein expression in lymphocytes exposed to low gamma-ray dose

Energy Technology Data Exchange (ETDEWEB)

Manzanares A, E.; Vega C, H.R.; Letechipia de Leon, C. [Unidades Academicas de Estudios Nucleares, UAZ, A.P. 336, 98000 Zacatecas (Mexico)]. E-mail: emanz@cantera.reduaz.mx; Guzman E, L.J. [Unidad Academica de Biologia Experimental, Guadalupe, Zacatecas (Mexico); Garcia T, M. [LIBRA, Centro I and D, Campus Miguel Delibes, Valladolid 47011 (Spain)

2004-07-01

The purpose of this study was to evaluate the effect of low gamma ray intensity upon Hsp70 expression in human Iymphocytes. The heat shock proteins (Hsp) family, are a group of proteins present in all living organism, therefore there are highly conserved and are related to adaptation and evolution. At cellular level these proteins acts as chaperones correcting denatured proteins. When a stress agent, such heavy metals, UV, heat, etc. is affecting a cell a response to this aggression is triggered only through over expression of Hsp. Several studies has been carried out in which the cellular effect are observed, mostly of these studies uses large doses, but very few studies are related with low doses. Blood of healthy volunteers was obtained and the Iymphocytes were isolated by ficoll- histopaque gradient. Experimental lots were irradiated in a {sup 137} Cs gamma-ray. Hsp70 expression was found since 0.5 c Gy, indicating a threshold to very low doses of gamma rays. (Author)

Effects of low dose gamma-ray radiation on the seed germination and physiological activity of vegetable crops

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Baek, M. H.; Lee, Y. G. [KAERI, Taejon (Korea, Republic of); Jung, K. H. [Kyunghee Univ., Yongin (Korea, Republic of)

2000-10-01

To determine the effect of low dose gamma-ray radiation on the germination rate and physiology of germinative seeds of Chinese cabbage(Brassica campestris L. cv. Hanyoreum) and radish(Raphanus sativus L. cv. Chungsukoungzoung). The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage of induction. The germination rate of Chinese cabbage increased at 4 Gy-, 10 Gy- and 50 Gy irradiation group and that of radish increased at 2 Gy-, 6 Gy- and 10 Gy irradiation group. The seedling height of Chinese cabbage and radish increased positively in low dose irradiation group. The seedling height of Chinese cabbage was noticeably higher at 4 Gy and 10 Gy irradiation group and that of radish at 6 Gy irradiation group. The protein contents of seeds irradiated with low dose gamma-ray radiation was increased compared to that of the control especially at the early stage of induction. The enzyme activity of seeds irradiated with low dose of gamma-ray radiation was increased at 4 Gy and 10 Gy irradiation group. These results suggest that the germination and physiological activity of old seeds could be stimulated promisingly by the low dose gamma-ray radiation.

Simulation studies to determine the gamma radiation dose due to natural radioactivity in construction materials in dwellings

International Nuclear Information System (INIS)

Shetty, P.G.; Chougaonkar, M.P.; Mayya, Y.S.; Puranik, V.D.

2008-01-01

Gamma radiation dose is imparted to the living due to the natural radionuclides present in the environmental materials, including the building materials used for construction of dwellings. The radionuclides responsible for natural radiation dose are the primordial radionuclides of 232 Th, 238 U series and the 40 K. These nuclides together with their daughters give rise to external gamma ray dose as well as the inhalation doses arising from the short-lived radon/thoron gases and their progenies that are exhaled from the walls of the construction materials. The radioactivity inside a room and the radiation dose caused by it mainly depends on the concentration of the above mentioned radionuclides in the building materials and type/properties like thickness, density etc. of the material used for construction. A computational model for a standard house (without windows and door) has been designed using Monte Carlo N-particle code (MCNP). The code works on probability theory. The present paper discusses the individual contribution of doses from 40 K, uranium and thorium series. Further variation in the gamma doses due to different building materials and densities are also discussed. (author)

Effect of different doses of gamma radiation on shelf life of mango (Mangifera indica L.) fruits cv. Dashehari

International Nuclear Information System (INIS)

Baghel, B.S.; Gupta, N.; Tiwari, R.

2005-01-01

The mango fruits cv. Dashehari irradiated with different doses of gamma radiation for extending their shelf life and for stabilizing the market demand, revealed that irradiation of mango fruits with 200 Gy gamma radiation increase the post harvest life of 93.75 percent mango fruits by 12 days over control (46.66 percent) and proved superior to maintain the considerable physico-chemical composition of mango fruits as compared to control and higher doses of gamma radiation. (author)

Shelf Life of Tilapia Fillets Treated with low dose Gamma Irradiation

International Nuclear Information System (INIS)

Mohamed, W.S.; El-Mossalami, I.I.

2009-01-01

The bacterial load (total bacterial count), Psychrophilic count, chemical and sensory examinations in Tilapia fish fillets were determined to evaluate its sanitary status and to increase its storage period during storage at -18 degree C for one year. The experiment was carried out at the time of receiving the samples and after gamma radiation treatment with dose levels of 1, 2 and 3 kGy. The initial total bacterial count was 5.4x10 0 cfu/gm and the psychrophilic count was 4x10 5 cfu/gm; it was slightly increased during freezing storage. The chemical parameters were more indicative in evaluating the shelf life of frozen fish; as they exceeded the permissible limits, so that the frozen non-irradiated samples were rejected after 6 months. The exposure to gamma irradiation at a dose of 1 kGy extended the storage time of the samples to 9 months while irradiation with 3 kGy extended the storage time of the samples to 12 months without changing its quality attributes. The quality during storage at -18 degree C of non irradiated and irradiated fish fillets was investigated every 3 months for one year by measuring the bacterial counts, chemical parameters and sensorial evaluation of the samples to study the effect of irradiation on increasing the storage time of fish fillets. So, it is recommended that fish fillets should be properly cleaned, packaged and exposed to gamma irradiation at a dose of 3 kGy to extend its freezing storage period

The influence of geology on terrestrial gamma radiation dose rate in Pahang state, Malaysia

International Nuclear Information System (INIS)

Gabdo, H.T.; Ramli, A.T.; Sanusi, M.S.; Garba, N.N.; Saleh, M.A.

2015-01-01

Terrestrial gamma radiation dose (TGRD) rate measurements have been made in Pahang state, Malaysia. Significant variations were found between TGRD measurements and the underlying geological formations. In some cases revealing significant elevations of TGRD. The acid-intrusive geological formation has the highest mean TGRD measurement of 367 nGy/h -1 . This is more than six times the world average value of 59 nGy/h -1 , while the quaternary geological formation has the lowest mean gamma radiation dose rate of 99 nGy h -1 . The annual effective dose equivalent outdoor to the population was 0.216 mSv. The lifetime equivalent dose and relative lifetime cancer risks for an individual living in Pahang state were 81 mSv and 4.7 x 10 -3 respectively. These values are more than two times the world average of 34 mSv and 1.95 x 10 -3 respectively. (author)

Adjustment of gamma radiation doses for sterilization of Egyptian surgical sutures

International Nuclear Information System (INIS)

Tawfik, Z.S.; Helmy, M.M.; Roushdy, H.M.

1984-01-01

The adjustment of gamma radiation doses for sterilization of catguts under local manufacturing conditions has been performed. Average total initial counts for aerobic and anaerobic bacteria per item were relatively low, in the range of 1000 counts for aerobic and 10 counts for anaerobic bacteria. The microfiora (aerobic bacteria) of the studied sutures were isolated and identified to be: Bacillus sp.; Micrococcus varians, Micrococcus roseus, and Staphylococcus. Each purified and identified isolate was exposed to gamma radiation both in liquid media (broth) and in the preservative in which the sutures were supplied by the company. The LD values of the most resistant microorganisms in both case of liquid media and preservative, were obtained to be around 5 KGy. Deliberately contaminated sterile sutures with each isolate and with mixture of isolates were studied. The sterilizing dose was obtained to be 20KGy for most heavily contaminated items (10 10 counts) irradiated both in saline and in preservative. This sterilizing dose was found to be dependent of the initial viable counts. This value was considered to be a safe value for radiosterilization of the studied sutures preserved in isopropyl alcohol, glycerin, and water (90:3.5:16)

Gamma knife radiosurgery for ten or more brain metastases. Analysis of the whole brain irradiation doses

International Nuclear Information System (INIS)

Nakaya, Kotaro; Hori, Tomokatsu; Izawa, Masahiro; Yamamoto, Masaaki

2002-01-01

Gamma knife (GK) radiosurgery has recently been recognized as the most powerful treatment modality in managing patients with brain metastasis, be they radioresistant or not, solitary or multiple. Very recently, this treatment has been employed in patients with numerous brain metastases, even those with 10 or more lesions. However, cumulative irradiation doses to the whole brain, with such treatment, remain unknown. Since the Gamma Plan ver. 5.10 (ver. 5.30 is presently available, Leksell Gamma Plan) became available in November, 1998, 105 GK procedures have been performed at our two facilities, Tokyo Women's Medical University and Katsuta Hospital Mito Gamma House. The median lesion number was 17, ranging 10-43, and the median cumulative volume of all tumors was 8.72 cm 3 , ranging 0.41-81.41 cm 3 . The selected doses at the lesion periphery ranged 12-25 Gy, the median being 20 Gy. Based on these treatment protocols, the cumulative irradiation dose was computed. The median cumulative irradiation dose to the whole brain was 4.83, ranging 2.16-8.51 Gy: the median integrated dose to the whole brain was 6.2 J, ranging 2.16-11.9 J. The median brain volumes receiving ≥2, ≥5, ≥10, ≥15 and ≥20 Gy were 1105 (range: 410-1501), 309 (46-1247), 64 (13-282), 24 (2-77), and 8 (0-40) cm 3 , respectively. The cumulative whole brain irradiation doses for patients with numerous radiosurgical targets were considered not to exceed the threshold level of normal brain necrosis. (author)

Morphological changes induced by different doses of gamma irradiation in garlic sprouts

Energy Technology Data Exchange (ETDEWEB)

Pellegrini, C.N. E-mail: pellegri@criba.edu.ar; Croci, C.A.; Orioli, G.A

2000-03-01

The objective of this work was to evaluate the effects of different doses of gamma rays applied in dormancy and post-dormancy on garlic bulbs in relation with some morphophysiological parameters. High (commercial) doses cause the complete inhibition of sprouting and mitosis (due to nuclear aberrations). Relatively low doses show no effects on bulbs but doses of 10 Gy applied in post-dormancy reduce sprouting and stop mitosis. This inhibition becomes noticeable from 150 days post-harvest onwards. Exogenous growth regulators can reverse these effects. Results may reinforce the good practice of radioinhibition processes in garlic. (author)0.

Using RADFET for the real-time measurement of gamma radiation dose rate

Science.gov (United States)

Andjelković, Marko S.; Ristić, Goran S.; Jakšić, Aleksandar B.

2015-02-01

RADFETs (RADiation sensitive Field Effect Transistors) are integrating ionizing radiation dosimeters operating on the principle of conversion of radiation-induced threshold voltage shift into absorbed dose. However, one of the major drawbacks of RADFETs is the inability to provide the information on the dose rate in real-time using the conventional absorbed dose measurement technique. The real-time monitoring of dose rate and absorbed dose can be achieved with the current mode dosimeters such as PN and PIN diodes/photodiodes, but these dosimeters have some limitations as absorbed dose meters and hence they are often not a suitable replacement for RADFETs. In that sense, this paper investigates the possibility of using the RADFET as a real-time dose rate meter so that it could be applied for simultaneous online measurement of the dose rate and absorbed dose. A RADFET sample, manufactured by Tyndall National Institute, Cork, Ireland, was tested as a dose rate meter under gamma irradiation from a Co-60 source. The RADFET was configured as a PN junction, such that the drain, gate and source terminals were grounded, while the radiation-induced current was measured at the bulk terminal, whereby the bulk was successively biased with 0 , 10 , 20  and 30 V. In zero-bias mode the radiation-induced current was unstable, but in the biased mode the current response was stable for the investigated dose rates from 0.65  to 32.1 Gy h-1 and up to the total absorbed dose of 25 Gy. The current increased with the dose rate in accordance with the power law, whereas the sensitivity of the current read-out was linear with respect to the applied bias voltage. Comparison with previously analyzed PIN photodiodes has shown that the investigated RADFET is competitive with PIN photodiodes as a gamma radiation dose rate meter and therefore has the potential to be employed for the real-time monitoring of the dose rate and absorbed dose.

Using RADFET for the real-time measurement of gamma radiation dose rate

International Nuclear Information System (INIS)

Andjelković, Marko S; Ristić, Goran S; Jakšić, Aleksandar B

2015-01-01

RADFETs (RADiation sensitive Field Effect Transistors) are integrating ionizing radiation dosimeters operating on the principle of conversion of radiation-induced threshold voltage shift into absorbed dose. However, one of the major drawbacks of RADFETs is the inability to provide the information on the dose rate in real-time using the conventional absorbed dose measurement technique. The real-time monitoring of dose rate and absorbed dose can be achieved with the current mode dosimeters such as PN and PIN diodes/photodiodes, but these dosimeters have some limitations as absorbed dose meters and hence they are often not a suitable replacement for RADFETs. In that sense, this paper investigates the possibility of using the RADFET as a real-time dose rate meter so that it could be applied for simultaneous online measurement of the dose rate and absorbed dose. A RADFET sample, manufactured by Tyndall National Institute, Cork, Ireland, was tested as a dose rate meter under gamma irradiation from a Co-60 source. The RADFET was configured as a PN junction, such that the drain, gate and source terminals were grounded, while the radiation-induced current was measured at the bulk terminal, whereby the bulk was successively biased with 0 , 10 , 20  and 30 V. In zero-bias mode the radiation-induced current was unstable, but in the biased mode the current response was stable for the investigated dose rates from 0.65  to 32.1 Gy h −1 and up to the total absorbed dose of 25 Gy. The current increased with the dose rate in accordance with the power law, whereas the sensitivity of the current read-out was linear with respect to the applied bias voltage. Comparison with previously analyzed PIN photodiodes has shown that the investigated RADFET is competitive with PIN photodiodes as a gamma radiation dose rate meter and therefore has the potential to be employed for the real-time monitoring of the dose rate and absorbed dose. (paper)

Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

Science.gov (United States)

Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

2001-01-01

The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

Fieldable computer system for determining gamma-ray pulse-height distributions, flux spectra, and dose rates from Little Boy

International Nuclear Information System (INIS)

Moss, C.E.; Lucas, M.C.; Tisinger, E.W.; Hamm, M.E.

1984-01-01

Our system consists of a LeCroy 3500 data acquisition system with a built-in CAMAC crate and eight bismuth-germanate detectors 7.62 cm in diameter and 7.62 cm long. Gamma-ray pulse-height distributions are acquired simultaneously for up to eight positions. The system was very carefully calibrated and characterized from 0.1 to 8.3 MeV using gamma-ray spectra from a variety of radioactive sources. By fitting the pulse-height distributions from the sources with a function containing 17 parameters, we determined theoretical repsonse functions. We use these response functions to unfold the distributions to obtain flux spectra. A flux-to-dose-rate conversion curve based on the work of Dimbylow and Francis is then used to obtain dose rates. Direct use of measured spectra and flux-to-dose-rate curves to obtain dose rates avoids the errors that can arise from spectrum dependence in simple gamma-ray dosimeter instruments. We present some gamma-ray doses for the Little Boy assembly operated at low power. These results can be used to determine the exposures of the Hiroshima survivors and thus aid in the establishment of radation exposure limits for the nuclear industry

Incidence of leukemia among atomic bomb survivors in relation to neutron and gamma dose, Hiroshima and Nagasaki, 1950-71

International Nuclear Information System (INIS)

Ishimaru, Toranosuke; Otake, Masanori; Ichimaru, Michito.

1978-03-01

The incidence of leukemia during 1950-71 in the fixed mortality sample of atomic bomb survivors in Hiroshima and Nagasaki has been analyzed as a function of individual gamma and neutron kerma and marrow dose. Two dose response models were tested for each of acute leukemia, chronic granulocytic leukemia, and all types of leukemia, respectively. Each model postulates that leukemia incidence depends upon the sum of the separate risks imposed by the gamma ray and neutron doses; in Model I both are assumed to be directly proportional to the respective doses, while Model II assumes that while the risk from neutrons is directly proportional to the dose, the risk from gamma rays is proportional to dose-squared. Weighted regression analyses were performed for each model. When the two models were fitted to the data for all types of leukemia, the estimated regression coefficients corresponding to the neutron and gamma ray doses both differed significantly from zero, for each model. However, when analysis was restricted to acute leukemia, both the neutron and gamma ray coefficients were significant only for Model II, and with respect to chronic granulocytic leukemia, only the coefficient of the neutron dose was significant, using either Model I or Model II. It appeared that the responses of the two leukemia types differed by type of radiation. If the chronic granulocytic and acute leukemias are considered together, the Model II appears to fit the data slightly better than Model I, but neither models is rejected by the data. (author)

Pretreatment with low-dose gamma irradiation enhances tolerance to the stress of cadmium and lead in Arabidopsis thaliana seedlings.

Science.gov (United States)

Qi, Wencai; Zhang, Liang; Wang, Lin; Xu, Hangbo; Jin, Qingsheng; Jiao, Zhen

2015-05-01

Heavy metals are important environmental pollutants with negative impact on plant growth and development. To investigate the physiological and molecular mechanisms of heavy metal stress mitigated by low-dose gamma irradiation, the dry seeds of Arabidopsis thaliana were exposed to a Cobalt-60 gamma source at doses ranging from 25 to 150Gy before being subjected to 75µM CdCl2 or 500µM Pb(NO3)2. Then, the growth parameters, and physiological and molecular changes were determined in response to gamma irradiation. Our results showed that 50-Gy gamma irradiation gave maximal beneficial effects on the germination index and root length in response to cadmium/lead stress in Arabidopsis seedlings. The hydrogen peroxide and malondialdehyde contents in seedlings irradiated with 50-Gy gamma rays under stress were significantly lower than those of controls. The antioxidant enzyme activities and proline levels in the irradiated seedlings were significantly increased compared with the controls. Furthermore, a transcriptional expression analysis of selected genes revealed that some components of heavy metal detoxification were stimulated by low-dose gamma irradiation under cadmium/lead stress. Our results suggest that low-dose gamma irradiation alleviates heavy metal stress, probably by modulating the physiological responses and gene expression levels related to heavy metal resistance in Arabidopsis seedlings. Copyright © 2015 Elsevier Inc. All rights reserved.

Different gamma ray (60 Co) dose effects on Sorghum genotype germination

International Nuclear Information System (INIS)

Tabosa, Jose Nildo; Gomes, Roberto Vicente; Reis, Odemar Vicente dos; Colaco, Waldeciro

2004-01-01

In agriculture, applying irradiation is a very valuable way of obtaining vegetable products for human and animal consumption. Cobalt-60, one of the main sources of gamma-rays, is considered an important tool in plant breeding programs, which have the objective of promoting genetic variability of cultivars with resistance to adverse environments. In this research, the effects of different 60 Co doses on germination vigor and seed germination velocity of forage sorghum genotypes were evaluated. The study was carried out at the IPA (Empresa Pernambucana de Pesquisa Agropecuaria) in Recife, Pernambuco, Brazil. The work was installed in germination boxes, following laboratory recommendations. Thus, a experiment involving three sorghum genotypes (IPA 467-4-2, IPA 02-03-01, and Sudan 4202), five 60 Co doses (Zero, 150, 300, 350, and 400 Gy), was set up. The sees were irradiated before the beginning of the experiment being exposed to gamma rays from a 60 Co-source (cobalt irradiator) at DEN (Nuclear Engineering Department) of the UFPE (Pernambuco Federal University), Brazil. The work also had the objective of evaluating the sorghum genotypes x 60 Co dose interaction. The main results obtained showed that the sorghum genotype IPA 02-03-01 presented the greatest values of germination and vigor percentages, and seed germination velocity, when compared to the others evaluated, on 350 and 400 Gy of 60 Co doses. (author)

Radionuclide content in some building materials and gamma dose rate in dwellings in Cuba

International Nuclear Information System (INIS)

Brigido, Oslvaldo; Montalvan, Adelmo; Rosa, Ramon; Hernandez, Alberto

2008-01-01

Naturally occurring radionuclides in building materials are one of the sources of radiation exposure of the population. This study was undertaken with the purpose of determining radioactivity in some Cuban building materials and for assessing the annual effective dose to Cuban population due external gamma exposure in dwellings for typical Cuban room model. Forty four samples of raw materials and building products were collected in some Cuban provinces. The activity concentrations of natural radionuclides were determined by gamma ray spectrometry using a p-type coaxial high purity germanium detector and their mean values are in the ranges: 9 to 857 Bq.kg -1 for 40 K; 6 to 57 Bq.kg -1 for 226 Ra; and 1.2 to 22 Bq.kg -1 for 232 Th. The radium equivalent activity in the 44 samples varied from 4 Bq.kg -1 (wood) to 272 Bq.kg -1 (brick). A high pressure ionisation chamber was used for measuring of the indoor absorbed dose rate in 543 dwellings and workplaces in five Cuban provinces. The average absorbed dose rates in air ranged from 43 n Gy.h -1 (Holguin) to 73 n Gy.h -1 (Camaguey) and the corresponding population-weighted annual effective dose due to terrestrial gamma radiation was estimated to be 145 ± 40 μSv. This dose value is 16% higher than the calculated value for typical room geometry of Cuban house. (author)

GLODEP2: a computer model for estimating gamma dose due to worldwide fallout of radioactive debris

International Nuclear Information System (INIS)

Edwards, L.L.; Harvey, T.F.; Peterson, K.R.

1984-03-01

The GLODEP2 computer code provides estimates of the surface deposition of worldwide radioactivity and the gamma-ray dose to man from intermediate and long-term fallout. The code is based on empirical models derived primarily from injection-deposition experience gained from the US and USSR nuclear tests in 1958. Under the assumption that a nuclear power facility is destroyed and that its debris behaves in the same manner as the radioactive cloud produced by the nuclear weapon that attached the facility, predictions are made for the gamma does from this source of radioactivity. As a comparison study the gamma dose due to the atmospheric nuclear tests from the period of 1951 to 1962 has been computed. The computed and measured values from Grove, UK and Chiba, Japan agree to within a few percent. The global deposition of radioactivity and resultant gamma dose from a hypothetical strategic nuclear exchange between the US and the USSR is reported. Of the assumed 5300 Mton in the exchange, 2031 Mton of radioactive debris is injected in the atmosphere. The highest estimated average whole body total integrated dose over 50 years (assuming no reduction by sheltering or weathering) is 23 rem in the 30 to 50 degree latitude band. If the attack included a 100 GW(e) nuclear power industry as targets in the US, this dose is increased to 84.6 rem. Hotspots due to rainfall could increase these values by factors of 10 to 50

Effect of low doses gamma irradiation on seed, bulblets and bulbs of onion

International Nuclear Information System (INIS)

Al-Oudat, Mohammad

1991-10-01

Presowing seed irradiation has been reported as a useful application of radiation in agriculture to stimulate growth and increase the yield of certain crops. To the best of our knowledge the feasibility of this treatment has not yet been tested on onion in Syria. The effect of low doses gamma irradiation on onion seeds, bulblets and bulbs of two local varieties, red and white, was studied during three consecutive seasons (1986 - 1988). Air dried seeds were irradiated by gamma rays from 137 Cs source. Five, 10, 15, 20 and 30 GY, were applied at dose rate of 9.8 Gy/min. The irradiation of onion bulblets and bulbs were carried out with gamma-rays from 60 Co source at a dose rate of 0.5 Gy/min. using 1, 2, 3, 4 and 5 Gy. Within 7 - 10 days after irradiation, both controlled and irradiated seeds, bulblets and bulbs were sown in the field in complete randomized block design with 4 replicates. Irradiation of seeds with doses of 5, 10 and 15 Gy led to highly significant increases in bulblets yield in the three seasons. The increases ranged from 14.5 to 22.1 for red variety and from 16.2 to 22.3 for white variety. The irradiation of bulblets with 1 and 2 Gy increase significantly the yield of bulbs by 21.6 - 26.0% for red variety and 21.6 - 24.4% for white variety. A considerable increase in seed yield was obtained after irradiation of bulbs with 1 and 2 Gy doses. The average increment was about 21.0% for both varieties. Large scale application were performed in 1989 and 1990 using doses of 10 Gy for seeds and 1 Gy for bulblets and bulbs. A considerable increase in the yield was obtained. The average percentage increment was 16.9% and 23.3% for seeds, 18.6 and 20.9% for bulblets, 24.8 and 27.3% for bulbs, for red and white varieties respectively. Therefore, presowing irradiation of seeds, bulblets and bulbs of onion with low doses of gamma-rays (5 - 15 Gy for seeds and 1 - 2 Gy for bulblets and bulbs) can be of practical application resulting in improvement of yield of

Effect of sublethal doses of gamma radiation on DNA super helicity and survival of human fibroblasts

International Nuclear Information System (INIS)

Koceva-Chyla, A.

1992-01-01

Effect of sublethal doses of gamma radiation on cell survival and DNA super helicity in human fibroblasts was studied. Cell survival was estimated on the basis the basis of clonal growth of irradiated fibroblasts in monolayer culture in vitro. The nucleoid sedimentation technique was used to study ionizing radiation-induced DNA damage in vivo as well as to examine DNA super helicity. Increased concentrations of ethidium bromine (EB) were used to titrate the DNA super coiling response in non-irradiated cells. This response consisted of a relaxation phase (1-5 μg/ml EB) and rewinding phase (5-20 μg/ml EB). Observed biphasic dependence of sedimentation distance of nucleoid on the concentration of EB suggests the dye altered the amount of DNA super coiling in situ. The degree of DNA super coiling and thus the sedimentation rate of nucleoid in absence of EB was very sensitive to strand break induced in DNA by the doses of gamma radiation employed in the cell survival assay. Doses of 2-8 Gy of gamma radiation induced a dose -dependent reduction in the sedimentation of nucleoid. Loss of negative DNA super coiling was initially rapid (about 30% after the dose of 2 Gy) and then proceeded at a slower rate (about 35% and 48% after the doses of 4 Gy and 8 Gy respectively), indicating a significant relaxation of nucleoid structure at the doses of gamma radiation greater than 4 Gy, at which also significant decrease in fibroblasts survival occurred. Significant loss of negative DNA super coiling within the range of doses of gamma radiation resulting in significant decrease of cell survival suggests that destabilizing effect of radiation on DNA tertiary- and quaternary structures (extensive DNA breaks and relaxation of nucleonic super helicity) disturb normal functions and replications of genomic DNA, in consequence leading to a reproductive death of cells. Considering the sensitivity and simplicity of the method, the nucleoid sedimentation technique might be also a useful tool

Assessment of the radiological impact of gamma and radon dose rates at former U mining sites in Tajikistan

International Nuclear Information System (INIS)

Lespukh, E.; Stegnar, P.; Yunusov, M.; Tilloboev, H.; Zyazev, G.; Kayukov, P.; Hosseini, A.; Strømman, G.; Salbu, B.

2013-01-01

An assessment of the radiological situation due to exposure to gamma radiation, radon ( 222 Rn) and thoron ( 220 Rn) was carried out at former uranium (U) mining and processing sites in Taboshar and at Digmai in Tajikistan. Gamma dose rate measurements were made using various field instruments. 222 Rn/ 220 Rn measurements were carried out with field instruments for instantaneous measurements and then discriminative 222 Rn/ 220 Rn solid state nuclear track detectors (SSNTD) were used for longer representative measurements. The detectors were exposed for an extended period of time in different outdoor and indoor public and residential environments at the selected U legacy sites. The results showed that gamma, 222 Rn and 220 Rn doses were in general low, which consequently implies a low to relatively low radiological risk. The radiation doses deriving from external radiation (gamma dose rate), indoor 222 Rn and 220 Rn with their short-lived progenies did not exceed national or international standards. At none of the sites investigated did the average individual annual effective doses exceed 10 mSv, the recommended threshold value for the general public. A radiation hazard could be associated with exceptional situations, such as elevated exposures to ionizing radiation at the Digmai tailings site and/or in industrial facilities, where gamma and 222 Rn/ 220 Rn dose rates could reach values of several 10 mSv/a. Current doses of ionizing radiation do not represent a hazard to the health of the resident public, with the exception of some specific situations. These issues should be adequately addressed to further reduce needless exposure of the resident public to ionizing radiation

Temporal reduction of the external gamma dose rate due to 137Cs mobility in sandy beaches

International Nuclear Information System (INIS)

Rizzotto, M.; Toso, J.; Velasco, H.; Belli, M.; Sansone, U.

2009-01-01

In the present paper the contribution to the external gamma dose rate due o 137 Cs in soil as a function of time is presented. Sampling sites were elected along the Calabria and Basilicata Regions coastal beaches (southern art of Italy) to assess the external gamma dose rate in air, 1 m above the round level. A convection-dispersion model, with constant parameters was sed to approximate the radiocesium soil vertical migration. The model was calibrated using the initial 137 Cs activity deposition in this region Chernobyl fallout) and 137 Cs activity concentration down the soil profile, measured 10 years later. The dispersion coefficient and the advection velocity values, were respectively: 2.17 cm 2 y -1 and 0.32 cm -1 . The Radionuclide Software Package (RSP), which uses a Monte Carlo simulation code, was used to determine the primary 137 Cs gamma dose contribution in air 1 m above the ground surface. The resulting 137 Cs external dose rate ranged from 0.42 nGy h -1 in 1986, to 0.05 nGy h -1 in 007. (author)

Verification by the FISH translocation assay of historic doses to Mayak workers from external gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Sotnik, Natalia V.; Azizova, Tamara V. [Southern Urals Biophysics Institute (SUBI), Ozyorsk, Chelyabinsk Region (Russian Federation); Darroudi, Firouz [Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands); College of North Atlantic, Department of Health Science, Centre for Human Safety and Environmental Research, Doha (Qatar); Ainsbury, Elizabeth A.; Moquet, Jayne E.; Lloyd, David C.; Hone, Pat A.; Edwards, Alan A. [Public Health England, Chilton, Oxfordshire (United Kingdom); Fomina, Janna [Leiden University Medical Center, Department of Toxicogenetics, Leiden (Netherlands)

2015-11-15

The aim of this study was to apply the fluorescence in situ hybridization (FISH) translocation assay in combination with chromosome painting of peripheral blood lymphocytes for retrospective biological dosimetry of Mayak nuclear power plant workers exposed chronically to external gamma radiation. These data were compared with physical dose estimates based on monitoring with badge dosimeters throughout each person's working life. Chromosome translocation yields for 94 workers of the Mayak production association were measured in three laboratories: Southern Urals Biophysics Institute, Leiden University Medical Center and the former Health Protection Agency of the UK (hereinafter Public Health England). The results of the study demonstrated that the FISH-based translocation assay in workers with prolonged (chronic) occupational gamma-ray exposure was a reliable biological dosimeter even many years after radiation exposure. Cytogenetic estimates of red bone marrow doses from external gamma rays were reasonably consistent with dose measurements based on film badge readings successfully validated in dosimetry system ''Doses-2005'' by FISH, within the bounds of the associated uncertainties. (orig.)

Crystal growth and thermoluminescence response of NaZr{sub 2}(PO{sub 4}){sub 3} at high gamma radiation doses

Energy Technology Data Exchange (ETDEWEB)

Ordóñez-Regil, E., E-mail: eduardo.ordonez@inin.gob.mx [Depto. de Química, Gerencia de Ciencias Básicas, Instituto Nacional de Investigaciones Nucleares, AP 18-1027, CP 11801 México D.F. (Mexico); Contreras-Ramírez, A., E-mail: aida.contreras@inin.gob.mx [Depto. de Química, Gerencia de Ciencias Básicas, Instituto Nacional de Investigaciones Nucleares, AP 18-1027, CP 11801 México D.F. (Mexico); Depto. de Tecnología de Materiales, Gerencia de Ciencias Aplicadas, Instituto Nacional de Investigaciones Nucleares, AP 18-1027, CP 11801 México D.F. (Mexico); Facultad de Ciencias, Universidad Autónoma del Estado de México, Unidad Académica el Cerrillo, Piedras Blancas, AP 2-139, CP 50000 Toluca Estado de México (Mexico); Fernández-Valverde, S.M., E-mail: suilma.fernandez@inin.gob.mx [Depto. de Química, Gerencia de Ciencias Básicas, Instituto Nacional de Investigaciones Nucleares, AP 18-1027, CP 11801 México D.F. (Mexico); González-Martínez, P.R., E-mail: pedro.gonzalez@inin.gob.mx [Depto. de Física, Gerencia de Ciencias Básicas, Instituto Nacional de Investigaciones Nucleares, AP 18-1027, CP 11801 México D.F. (Mexico); Carrasco-Ábrego, H., E-mail: hector.carrasco@inin.gob.mx [Depto. Aceleradores, Gerencia de Ciencias Ambientales, Instituto Nacional de Investigaciones Nucleares, AP 18-1027, CP 11801 México D.F. (Mexico)

2013-11-15

Graphical abstract: -- Highlights: •NaZr{sub 2}(PO{sub 4}){sub 3} exposed to gamma doses of 10, 30 and 50 MGy. •Gamma radiation produced growth of the crystal size of the NZP. •Morphology changes were reversible by heating. •Linear relationship between the thermoluminescence and the applied gamma dose. •This property could be useful for high-level gamma dosimetry. -- Abstract: This work describes the synthesis and characterization of NaZr{sub 2}(PO{sub 4}){sub 3}. The stability of this material under high doses of gamma radiation was investigated in the range of 10–50 MGy. Samples of unaltered and gamma irradiated NaZr{sub 2}(PO{sub 4}){sub 3} were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and thermoluminescence. The results showed that while functional groups were not affected by the gamma irradiation, morphology changes were observed with increasing doses of gamma irradiation. The morphology of the non-irradiated compound is agglomerated flakes; however, irradiation at 10 MGy splits the flakes inducing the formation of well-defined cubes. Gamma irradiation induced the crystal size of the NaZr{sub 2}(PO{sub 4}){sub 3} to grow. The heat treatment (973 K) of samples irradiated at 50 MGy resulted in the recovery of the original morphology. Furthermore, the thermoluminescence analysis of the irradiated compound is reported.

Terrestrial gamma radiation dose study to determine the baseline for environmental radiological health practices in Melaka state, Malaysia

International Nuclear Information System (INIS)

Ramli, Ahmad Termizi; Sahrone, Sallehudin; Wagiran, Husin

2005-01-01

Environmental terrestrial gamma radiation dose rates were measured throughout Melaka, Malaysia, over a period of two years, with the objective of establishing baseline data on the background radiation level. Results obtained are shown in tabular, graphic and cartographic form. The values of terrestrial gamma radiation dose rate vary significantly over different soil types and for different underlying geological characteristics present in the study area. The values ranged from 54 ± 5 to 378 ± 38 nGy h -1 . The highest terrestrial gamma dose rates were measured over soil types of granitic origin and in areas with underlying geological characteristics of an acid intrusive (undifferentiated) type. An isodose map of terrestrial gamma dose rate in Melaka was drawn by using the GIS application 'Arc View'. This was based on data collected using a NaI(Tl) scintillation detector survey meter. The measurements were taken at 542 locations. Three small 'hot spots' were found where the dose rates were more than 350 nGy h -1 . The mean dose rates in the main population areas in the mukims (parishes) of Bukit Katil, Sungai Udang, Batu Berendam, Bukit Baru and Bandar Melaka were 154 ± 15, 161 ± 16, 160 ± 16, 175 ± 18 and 176 ± 18 nGy h -1 , respectively. The population-weighted mean dose rate throughout Melaka state is 172 ± 17 nGy h -1 . This is lower than the geographical mean dose rate of 183 ± 54 nGy h -1 . The lower value arises from the fact that most of the population lives in the central area of the state where the lithology is dominated by sedimentary rocks consisting of shale, mudstone, phyllite, slate, hornfels, sandstone and schist of Devonian origin which have lower associated dose rates. The mean annual effective dose to the population from outdoor terrestrial gamma radiation was estimated to be 0.21 mSv. This value is higher than the world average of 0.07 mSv

Determination of the distal dose edge in a human phantom by measuring the prompt gamma distribution: a Monte Carlo study

Energy Technology Data Exchange (ETDEWEB)

Min, Chul Hee; Lee, Han Rim; Yeom, Yeon Su; Cho, Sung Koo; Kim, Chan Hyeong [Hanyang University, Seoul (Korea, Republic of)

2010-06-15

The close relationship between the proton dose distribution and the distribution of prompt gammas generated by proton-induced nuclear interactions along the path of protons in a water phantom was demonstrated by means of both Monte Carlo simulations and limited experiments. In order to test the clinical applicability of the method for determining the distal dose edge in a human body, a human voxel model, constructed based on a body-composition-approximated physical phantom, was used, after which the MCNPX code was used to analyze the energy spectra and the prompt gamma yields from the major elements composing the human voxel model; finally, the prompt gamma distribution, generated from the voxel model and measured by using an array-type prompt gamma detection system, was calculated and compared with the proton dose distribution. According to the results, effective prompt gammas were produced mainly by oxygen, and the specific energy of the prompt gammas, allowing for selective measurement, was found to be 4.44 MeV. The results also show that the distal dose edge in the human phantom, despite the heterogeneous composition and the complicated shape, can be determined by measuring the prompt gamma distribution with an array-type detection system.

Analysis of gamma dose for 4,8 gU/cm3 density silicide core at the RSG-GAS reactor using MCNP code

International Nuclear Information System (INIS)

Ardani

2011-01-01

Radiation safety analysis should be done following of substitution of fuel density of 2.96 gU/cc to density of 4,8 gU/cc silicide fuels for the RSG-GAS reactor. MCNP-5 code has been used to perform gamma dose calculation of the RSG-GAS reactor. Gamma radiation source at reactor consists of capture gamma rays, prompt fission gamma rays, and gamma rays of decay of fission and activation products. The strength of the prompt fission gamma rays is obtained by gamma releases of fission process of U-235 and reactor power of 30 MWt., during 46,6 days operation. Radiation dose is calculated at the experimental hall by detection point at the surface of outer of biological shielding and the operation hall by detection point at the top of the pool. The calculation is conducted at reactor on the normal operation and on the worst postulated accident causing the water level at the pool decreases. Calculation result shows that the biggest source strength of gamma rays come from the decay process. The highest calculated dose at the experiment hall is 4,07x10 -3 μSv/h, far from the maximum external dose permitted 25 μSv/h. The highest calculated dose at the operation hall is 19.98 μSv/h. Even though the calculated dose is still acceptable but this is close to the maximum permitted dose for worker. It concluded that loading of 4,8 gU/cc silicide fuel for the RSG-GAS still safe. (author)

Gamma dose rate estimation and operation management suggestions for decommissioning the reactor pressure vessel of HTR-PM

Energy Technology Data Exchange (ETDEWEB)

Sheng Fang; Hong Li; Jianzhu Cao; Wenqian Li; Feng Xie; Jiejuan Tong [Institute of Nuclear and New Energy Technology, Tsinghua, University, Beijing (China)

2013-07-01

China is now designing and constructing a high temperature gas cooled reactor-pebble bed module (HTR-PM). In order to investigate the future decommissioning approach and evaluate possible radiation dose, gamma dose rate near the reactor pressure vessel was calculated for different cooling durations using QAD-CGA program. The source term of this calculation was provided by KORIGEN program. Based on the calculated results, the spatial distribution and temporal changes of gamma dose rate near reactor pressure vessel was systematically analyzed. A suggestion on planning decommissioning operation of reactor pressure vessel of HTRPM was given based on calculated dose rate and the Chinese Standard GB18871-2002. (authors)

Assessment of genetically significant doses to the Sofia population from natural gamma background

International Nuclear Information System (INIS)

Vasilev, G.; Khristova, M.

1977-01-01

Genetically significant dose to the population of Sofia city was assessed within a program covering larger urban communities in the country. Measurements were made of gamma background exposure rates in the gonadal region. Gonad doses were estimated using a screening factor of 0.73. Based on statistical data for total number of inhabitants and number of people of reproductive age, and on the mean annual gonad doses derived, calculations were made of genetically significant dose to the Sofia population. Base-line data were thus provided for an assessment of extra radiation dose resulting from occupational radiation exposure. (author)

Dose-rate effects on gamma-induced genetic injury in rat spermatogonia

International Nuclear Information System (INIS)

Vyglenov, A.

1990-01-01

Data for correlation between the reciprocal translocations (RT) yield in rat germ cells and the doses of 0.5 - 3.0 Gy are presented. A 60 Co source has been used with dose rates of 0.25, 8 x 10 -2 and 7 x 10 -3 Gy/min. The results from the cytogenetic analysis made 6 months after irradiation have shown an increase of the yield with the increase of the dose, which can be described as a linear unthreshold dependence. The dose rate effect is expressed in decrease of mutation frequency. The comparison with earlier author's data from similar experiments for acute irradiation allows to determine the RBE of gamma irradiation at the three dose rates investigated as 0.6, 0.2 and 0.1 respectively. The reported results are connected with the problem of variety specificity of the dose rate effect. 2 figs., 2 tabs., 15 refs

Dose verification to cochlea during gamma knife radiosurgery of acoustic schwannoma using MOSFET dosimeter.

Science.gov (United States)

Sharma, Sunil D; Kumar, Rajesh; Akhilesh, Philomina; Pendse, Anil M; Deshpande, Sudesh; Misra, Basant K

2012-01-01

Dose verification to cochlea using metal oxide semiconductor field effect transistor (MOSFET) dosimeter using a specially designed multi slice head and neck phantom during the treatment of acoustic schwannoma by Gamma Knife radiosurgery unit. A multi slice polystyrene head phantom was designed and fabricated for measurement of dose to cochlea during the treatment of the acoustic schwannoma. The phantom has provision to position the MOSFET dosimeters at the desired location precisely. MOSFET dosimeters of 0.2 mm x 0.2 mm x 0.5 μm were used to measure the dose to the cochlea. CT scans of the phantom with MOSFETs in situ were taken along with Leksell frame. The treatment plans of five patients treated earlier for acoustic schwannoma were transferred to the phantom. Dose and coordinates of maximum dose point inside the cochlea were derived. The phantom along with the MOSFET dosimeters was irradiated to deliver the planned treatment and dose received by cochlea were measured. The treatment planning system (TPS) estimated and measured dose to the cochlea were in the range of 7.4 - 8.4 Gy and 7.1 - 8 Gy, respectively. The maximum variation between TPS calculated and measured dose to cochlea was 5%. The measured dose values were found in good agreement with the dose values calculated using the TPS. The MOSFET dosimeter can be a suitable choice for routine dose verification in the Gamma Knife radiosurgery.

Life span and tumorigenesis in mice exposed to continuous low dose-rate gamma-rays

International Nuclear Information System (INIS)

Tanaka, Satoshi; Braga-Tanaka III, Ignacia; Takabatake, Takashi; Ichinohe, Kazuaki; Tanaka, Kimio; Matsumoto, Tsuneya; Sato, Fumiaki

2004-01-01

Two experiments were conducted to evaluate late biological effects of chronic low dose-rate radiation. 1: Late effects of chronic low dose-rate gamma-ray irradiation on SPF mice, using life span and pathological changes as parameters. Continuous irradiation for approximately 400 days was performed using 137 Cs gamma-rays at dose-rates of 20 mGy/day, 1 mGy/day and 0.05 mGy/day with accumulated doses equivalent to 8000 mGy, 400 mGy and 20 mGy, respectively. All mice were kept until their natural death. Statistical analyses show that the life spans of the both sexes irradiated at 20 mGy/day (p<0.0001) and of females irradiated at 1 mGy/day (p<0.05) were significantly shorter than those of the control group. There was no evidence of lengthened life span in mice continuously exposed to very low dose-rates of gama-rays. Pathodological examinations showed that the most frequently observed lethal neoplasms in males were malignant lymphomas, liver, lung, and soft tissue neoplasms, whereas, in females, malignant lymphomas and soft tissue neoplasms were common. No significant difference in the causes of death and mortality rates between groups. Hematopoietic neoplasms (malignant lymphoma and myeloid leukemia), liver, lung and soft tissue neoplasms, showed a tendency to appear at a younger age in both sexes irradiated at 20 mGy/day. Experiment 2: effects on the progeny of chronic low dose-rate gamma-ray irradiated SPF mice: preliminary study. No significant difference was observed between non-irradiated group and irradiated group with regards to litter size, sex ratio and causes of death in F1 and F2 mice. (author)

Flattening the Energy Response of a Scintillator Based Gamma Dose Rate Meter Coupled to SiPM

International Nuclear Information System (INIS)

Knafo, Y.; Manor, A.; Ginzburg, D.; Ellenbogen, M.; Osovizky, A.; Wengrowicz, U.; Ghelman, M.; Seif, R.; Mazor, T.; Kadmon, Y.; Cohen, Y.

2014-01-01

Among the newest emerging technologies that are used in the design of personal gamma radiation detection instruments, the silicon photomultiplier (SiPM) light sensor is playing an important role. This type of photo sensor is characterized by low power consumption, small dimensions and high gain. These special characteristics present applicable alternatives for the replacement of traditional gamma sensors based on scintillator coupled to Photomultiplier tubes (PMT) or on Geiger-Muller(G.M.) sensors. For health physics applications, flat energy response is required for a wide range of radio-nuclides emitting gamma rays of different energies. Scintillation based radiation instrumentation provides count rate and amplitude of the measured pulses. These pulses can be split in different bins corresponding to the energy of the measured isotopes and their intensity. The count rate and the energy of the measured events are related to the dose rate. The conversion algorithm applys a different calibration factor for each energy bin in order to provide an accurate dose rate response for a wide range of gamma energies. This work describes the utilization of an innovative approach for dose rate conversion by using the abilities of newest 32-bit microcontroller based ARM core architecture

Terrestrial Gamma Radiation Dose Rate of West Sarawak

Science.gov (United States)

Izham, A.; Ramli, A. T.; Saridan Wan Hassan, W. M.; Idris, H. N.; Basri, N. A.

2017-10-01

A study of terrestrial gamma radiation (TGR) dose rate was conducted in west of Sarawak, covering Kuching, Samarahan, Serian, Sri Aman, and Betong divisions to construct a baseline TGR dose rate level data of the areas. The total area covered was 20,259.2 km2, where in-situ measurements of TGR dose rate were taken using NaI(Tl) scintillation detector Ludlum 19 micro R meter NaI(Tl) approximately 1 meter above ground level. Twenty-nine soil samples were taken across the 5 divisions covering 26 pairings of 9 geological formations and 7 soil types. A hyperpure Germanium detector was then used to find the samples' 238U, 232Th, and 40K radionuclides concentrations producing a correction factor Cf = 0.544. A total of239 measured data were corrected with Cf resulting in a mean Dm of 47 ± 1 nGy h-1, with a range between 5 nGy h-1 - 103 nGy h-1. A multiple regression analysis was conducted between geological means and soil types means against the corrected TGR dose rate Dm, generating Dg,s= 0.847Dg+ 0.637Ds- 22.313 prediction model with a normalized Beta equation of Dg,s= 0.605Dg+ 0.395Ds. The model has an 84.6% acceptance of Whitney- Mann test null hypothesis when tested against the corrected TGR dose rates.

Separate assessment of natural beta and gamma dose-rates with TL from α-Al2O3:C single-crystal chips

International Nuclear Information System (INIS)

Kalchgruber, R.; Wagner, G.A.

2006-01-01

A measurement procedure was developed for fast and separate assessment of beta and gamma dose-rates in natural sediments using highly sensitive α-Al 2 O 3 :C single-crystal chips. The dosemeters were buried for periods from two days to three weeks in sediments with different layer structure and homogeneity. For each measurement, a pair of dosemeters was buried, in order to assess beta and gamma dose-rates separately. One dosemeter was wrapped only in thin plastic foil to shield it from alpha radiation, thus measuring beta + gamma components. The second one, used for the gamma component only, was packed additionally in a 1mm copper container for absorption of beta radiation. For calibration, another set of dosemeters was buried in reference soil with a well-known dose-rate and similar content of radioactive nuclides. By comparing the thermally stimulated luminescence signals from the dosemeters the gamma dose-rate and also, by subtraction, the beta dose-rate in the unknown soil could be determined. The calculated uncertainties were 5-7% and 10%, respectively. The resulting dose-rates for homogeneous and inhomogeneous media were compared with the results obtained by Ge- and on-site NaI-gamma-ray spectrometry. An agreement within 2σ-error limits was found for homogeneous media after only few days of exposure

Effect of low dose gamma-radiation upon Newcastle disease virus antibody level in chicken

International Nuclear Information System (INIS)

Vilic, M.; Gottstein, Z.; Ciglar Grozdanic, I.; Matanovic, K.; Miljanic, S.; Mazija, H.; Kraljevic, P.

2009-01-01

The specific antibody response against Newcastle disease virus in the blood serum of chickens hatched from eggs exposed to low dose gamma-radiation was studied. Materials and methods: Two groups of eggs of commercial meat chicken lines were irradiated with the dose of 0.30 Gy 60 Co gamma-rays before incubation and on the 19 th day of incubation, respectively. The same number of eggs unexposed to gamma-radiation served as controls. After hatching the group of chicken hatched from eggs irradiated on the 19 th day of incubation was not vaccinated while the group of chicken hatched from eggs irradiated before incubation was vaccinated on the 14 day. Specific serum anti-Newcastle disease virus antibodies were quantified by the hemagglutination inhibition assay with 4 HA units of Newcastle disease virus La Sota strain. Result: Specific antibody titres against Newcastle disease virus in the blood serum of chickens hatched from eggs irradiated before incubation and vaccinated on the 14 th day significantly increased on the 28 th day. Specific antibody titre against Newcastle disease virus in the blood serum of chickens hatched from eggs irradiated on the 19 th day of incubation and non-vaccinated was significantly higher on the 1 st and 14 th day. Conclusion: Acute irradiation of heavy breeding chicken eggs with the dose of 0.30 Gy 60 Co gamma-rays before incubation and on the 19 th day of incubation could have a stimulative effect on humoral immunity in chickens.

Sampling optimization trade-offs for long-term monitoring of gamma dose rates

NARCIS (Netherlands)

Melles, S.J.; Heuvelink, G.B.M.; Twenhöfel, C.J.W.; Stöhlker, U.

2008-01-01

This paper applies a recently developed optimization method to examine the design of networks that monitor radiation under routine conditions. Annual gamma dose rates were modelled by combining regression with interpolation of the regression residuals using spatially exhaustive predictors and an

Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

Science.gov (United States)

Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

2001-01-01

The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p < 0.05). Basal proliferation of leukocytes in the blood and spleen increased significantly with increasing dose (p < 0.05). Significant dose rate effects were observed only in thrombocyte counts. Plasma levels of transforming growth factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

Environmental gamma-ray dose measurements with thermoluminescence dosemeters (TLD) and environmental radiation characteristics

International Nuclear Information System (INIS)

Kanematsu, Seiko

1999-01-01

It is important to evaluate environmental gamma-ray exposure both at work and home in order to assess people's collective dosages. Environmental gamma radiation was measured for air-absorbed dose with a thermoluminescence dosemeter at various points in the workplace and Ningyotoge, and workplace radiation characteristics were analyzed. From the results, the public dose due to gamma rays generated artificially was assessed to be sufficiently lower than the annual limit. For indoor environments of the workplace, the maximum dosage rate among measured values was 97 nGy/h and the minimum value was 70 nGy/h, the average over one year was 83 nGy/h. The average annual outdoor dosage for a year was 82 nGy/ h. In Ningyotoge, the maximum was 103 nGy/h, minimum 60 nGy/h, and average 88 nGy/h. These values depend on the nature of the soil and weather factors, showing higher values in the summer than in the winter in the workplace. There was no significant difference in the dosage rate in houses and the workplace. (author)

Assessment of dose load of personnel in intratissue gamma beam therapy

International Nuclear Information System (INIS)

Stavitskij, R.V.; Zamyatin, O.A.; Varennikov, O.I.; Astakhova, I.V.

1995-01-01

Suggest a method for retrospective assessment of levels of irradiation of small groups of personnel exposed to radiation sources. Presents estimated values of cumulative and local doses obtained by personnel during intratissue gamma beam therapy carried out by manual consecutive injections of intrastats and irradiation sources. 3 refs.; 5 tabs

Measurement of high dose rates of 60Co by gamma activation of115In and 111Cd foils

International Nuclear Information System (INIS)

Haddad, Kh; Qattan, M.; Taleb, A.

2009-12-01

The high gamma dose rate measurement technique using nuclear reaction (γ,(γ ' ') was introduced in this work. This technique is cheap, easy, reliable, and independent of chemical and physical factors, which affect other techniques. The response to the absorbed dose in this technique is linear and can be used for high dose. Cd and In foils were irradiated using 60 Co source and the resulted isomer activities were measured using gamma spectrometer. These foils were calibrated to be used as dosemeter and its results were compared with conventional one. The dose distribution in the irradiation field was determined using In foils. (authors)

FTIR spectroscopy as an alternative tool for high gamma dose dosimetry using P(VDF-TrFE) fluorinated copolymers

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Adriana S.; Liz, Otavio S., E-mail: asm@cdtn.b [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Faria, Luiz O., E-mail: farialo@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-07-01

Poly(vinylidene fluoride) [PVDF] is a semicrystalline homopolymer and some of its fluorinated copolymer has demonstrated to have sensitiveness to high doses of ionizing radiation. We have recently proposed a semicrystalline fluorinated PVDF copolymer, the poly(vinylidene-trifluorethylene) [P(VDF-TrFE], as a candidate for measuring larger dose ranges. In fact, in these copolymers the optical absorption peak at 274 nm has been used to measure gamma doses ranging from 1.0 to 100.0 kGy and the melting latent heat, collected by differential scanning calorimetry (DSC), have been used to measure gamma doses from 1.0 to 1,000.0 kGy. In this paper, the infrared stretching vibration of radio-induced in-chain unsaturations (CH=CF) in P(VDF-TrFE) copolymers has been considered as an alternative tool for high dose dosimetric purposes. FTIR spectroscopic data revealed two optical absorption bands at 1754 cm{sup -1} and 1854 cm{sup -1} whose intensities are unambiguously related to gamma delivered doses ranging from 100.0 kGy to 1,000.0 kGy. Fading was evaluated one month after irradiation. The results indicate that the sample dose evaluation should be performed in the first two hours after being exposed to the radiation beam. The radio-induced formation of unsaturations was also investigated by ultraviolet and visible spectroscopy, which has confirmed the gradual increase of conjugated C=C bonds with the absorbed dose. Our results indicate that quantitative analysis of FTIR absorption bands is a useful tool to perform a product end-point dosimetry in radiation processing facilities that use high gamma dose irradiation. (author)

Exfoliated graphite with graphene flakes as potential candidates for TL dosimeters at high gamma doses.

Science.gov (United States)

Ortiz-Morales, A; López-González, E; Rueda-Morales, G; Ortega-Cervantez, G; Ortiz-Lopez, J

2018-06-06

Graphite powder (GP) subjected to microwave radiation (MWG) results in exfoliation of graphite particles into few-layered graphene flakes (GF) intermixed with partially exfoliated graphite particles (PEG). Characterization of MWG by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Raman spectroscopy reveal few-layer GF with sizes ranging from 0.2 to 5 µm. Raman D, G, and 2D (G') bands characteristic of graphitic structures include evidence of the presence of bilayered graphene. The thermoluminescent (TL) dosimetric properties of MWG are evaluated and can be characterized as a gamma-ray sensitive and dose-resistant material with kinetic parameters (activation energy for the main peak located at 400 and 408 K is 0.69 and 0.72 eV) and threshold dose (~1 kGy and 5 kGy respectively). MWG is a low-Z material (Z eff = 6) with a wide linear range of TL dose-response (0.170-2.5 kGy) tested at doses in the 1-20 kGy range with promising results for applications in gamma-ray dosimetry. Results obtained in gamma irradiated MWG are compared with those obtained in graphite powder samples (GP) without microwave treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dose Response Model of Biological Reaction to Low Dose Rate Gamma Radiation

International Nuclear Information System (INIS)

Magae, J.; Furikawa, C.; Hoshi, Y.; Kawakami, Y.; Ogata, H.

2004-01-01

It is necessary to use reproducible and stable indicators to evaluate biological responses to long term irradiation at low dose-rate. They should be simple and quantitative enough to produce the results statistically accurate, because we have to analyze the subtle changes of biological responses around background level at low dose. For these purposes we chose micronucleus formation of U2OS, a human osteosarcoma cell line, as indicators of biological responses. Cells were exposed to gamma ray in irradiation rom bearing 50,000 Ci 60Co. After irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and prospidium iodide, respectively. the number of binuclear cells bearing micronuclei was counted under a fluorescence microscope. Dose rate in the irradiation room was measured with PLD. Dose response of PLD is linear between 1 mGy to 10 Gy, and standard deviation of triplicate count was several percent of mean value. We fitted statistically dose response curves to the data, and they were plotted on the coordinate of linearly scale response and dose. The results followed to the straight line passing through the origin of the coordinate axes between 0.1-5 Gy, and dose and does rate effectiveness factor (DDREF) was less than 2 when cells were irradiated for 1-10 min. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose above 0.1 Gy when 5,000 binuclear cells were analyzed. In contrast, dose response curves never followed LNT, when cells were irradiated for 7 to 124 days. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose below 6 Gy, when cells were continuously irradiated for 124 days. These results suggest that dose response curve of biological reaction is remarkably affected by exposure

Near-term and late biological effects of acute and low-dose-rate continuous gamma-ray exposure in dogs and monkeys

International Nuclear Information System (INIS)

Spalding, J.F.; Holland, L.M.

1979-07-01

Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (inury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with gamma rays at 35 r/day until death to determine the amount of radiation-induced injry remaining in conditioned animals as a reduction in mean survival time. Dogs (50%) and monkeys (8%) died from injury incurred during conditioning exposures. Thus, the comparative response (in terms of lethality) of dogs and monkeys to dose protraction by acute dose fractionation was similar to what we would expect from a single acute dose. The mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approx. 1400 h). Thus, the hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35-R/day gamma-ray challenge exposure were greater (significant in dogs but not in monkeys) than for their control counterparts. Thus, long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than 4 times the acute LD 50 30 in dogs and approximately 2 times that in monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 Rat/day

A study on seasonal variations of indoor gamma dose in Bangladesh

International Nuclear Information System (INIS)

Miah, M. Idrish

2005-01-01

Monthly variation of gamma dose rate measured in indoor air of buildings of Bangladesh was found to vary cosinusoidally through a period of 1 year. Significant seasonal variations were observed. Maximum dose rate, however, was observed in January and a minimum in July. Dose rate in January was 32% higher than the annual average, whereas dose rate in July was 50% lower. Seasonally varied ventilation and air exchange rates of the houses might play an important role in the observed variation. The average reduction with respect to winter dose was 59% in summer. Because of lower ventilation and air exchange rates between indoor and outdoor atmosphere, it is expected that the indoor dose rate would be higher in basements than that of upper floors. Monthly dose rate was also found to be influenced by the meteorological conditions. Correlations between dose rate and temperature (r 2 =0.85), rainfall (r=-0.83) and atmospheric pressure (r=0.92) were obtained, but no significant correlation (r=-0.45) was seen between dose rate and humidity. The results show that the seasonal variations of indoor dose rates should be taken into account to estimate annual effective dose equivalent. (author)

Development of a dose simulation software for gamma irradiation systems

International Nuclear Information System (INIS)

Omi, Nelson Minoru

2000-01-01

The use of high temperature, thermal and chemical treatment are among the used sterilization process of food and many products. The ionizing radiation came as another option, it has being used for many purposes and it became available due to the technological development in the second half of the 20 th century. Together with sterilization, many uses of the ionizing radiation were developed, such as applications on health, industrial products and waste recycling, food irradiation, vulcanizing, polymerization and gems color enhancing. The 60 Co gamma stands out among the used radiation sources on commercial facilities. lt is used to optimize this process with many dose mapping tests. The objective of this work is to develop a software to simulate the doses in 60 Co gamma irradiation systems. lt can be used to optimize a process on the project stage of a facility and to make viability studies for new applications in installations already set up. The validation of this software was done comparing the simulation results with the dosimetry data of an operating irradiation plant. The flexibility of the software was verified with extra dosimetry tests performed in another sterilization facility. (author)

Effect of dose of gamma-rays and ethylmethane sulphonate on the germination and survival of induced mutations in pigeonpea

Energy Technology Data Exchange (ETDEWEB)

Premsekar, S [Central Inst. for Cotton Research, Coimbatore (India). Regional Station; Appadurai, R [Tamil Nadu Agricultural Univ., Coimbatore (India)

1981-06-01

The LD/sub 50/ values for germination and survival of the induced mutants (M/sub 1/) of pigeonpea (Cajanus cajan (Linn.) Millsp.) were attained with 20 and 15 krad when gamma-rays were used, and 30 and 40 mM concentration when EMS was used. In the combination treatments the half-kill dose for germination and survival was reached even at the low dose combination of 5 krad gamma-ray + 20 mM EMS. Higher doses resulted in lower pollen and seed fertility. The sterility was much enhanced in the combined treatments. The number of pods, seed yield and weight of seeds could be stimulated with 10 and 15 krad doses of gamma-rays and 20 mM of EMS. In combination treatments such a stimulatory effect was noticed in seed weight only.

Dose rate on the environment generated by a gamma irradiation plant

International Nuclear Information System (INIS)

Mangussi, J.

2011-01-01

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

Assessment of natural radioactivity concentrations and gamma dose levels around Shorapur, Karnataka

Energy Technology Data Exchange (ETDEWEB)

Rajesh, S.; Avinash, P.; Kerur, B. R., E-mail: kerurpbk@rediffmail.com.com [Department of Physics, Gulbarga University Kalaburagi – 585 106 India (India); Anilkumar, S. [Radiation Safety Systems Division, BARC, Mumbai - 400 085 (India)

2015-08-28

This study assesses the level of background radiation around Shorapur. The study region locates the western part of the Yadgir district of Karnataka. Shorapur and Shahapur talukas are mostly composed of clay, shale sandstone, granite rock and part of study area is black soil. Thirty sample locations were selected along the length and breadth of Shorapur and Shahapur taluka. Natural radionuclide activity concentrations in soil samples were determined using 4'X4' NaI (Tl) gamma spectroscopy. Outdoor gamma dose measurements in air at 1 m above ground level were determined using Rad Eye PRD survey meter. Estimated dose values are compared with the survey meter values and found to be good agreement between them and also with the data obtained from different other areas of Karnataka and India. The average values were found to be slightly higher in the present investigation.

In vitro study of dose rate effect on Leksell Gamma Knife Perfexion

International Nuclear Information System (INIS)

Pastykova, V.; Novotny, J. jr.; Vachelova, J.; Davidkova, M.; Liscak, R.

2018-01-01

The main purpose of the study is to evaluate the radiobiological effect of the dose rate changes in Leksell Gamma Knife (LGK) clinical conditions. In principle there are two reasons why dose rate on LGK is reduced during patient irradiation: 1) Co-60 sources decay with a half-life of 5.26 years and 2) using multiple iso-centers and conformal treatment plans (e.g. with blocked beams). This pilot study is an experimental work performed in vitro with medulloblastoma DAOY cells. Are there effects caused by low dose rate which could negatively influence the clinical outcome of the radiosurgery? (authors)

ZZ DOSDAT-2, Gamma and Electron Dose Conversion Factor Data Library for Body Organs

International Nuclear Information System (INIS)

1983-01-01

1 - Description of problem or function: Format: DOSDAT-R; Nuclides: gamma-ray and electron dose rates for whole-body and for various body organs (24) for air and water immersion and from ground-surface sources (approximately 500 radioactive nuclides). Origin: DLC-80/DRALIST library of radioactive decay data. The data are used to estimate the gamma-ray and electron dose rates for whole-body and for various body organs (24) for air and water immersion and from ground-surface sources. The data are given for approximately 500 radioactive nuclides. 2 - Method of solution: The data were computed by the CCC-400 DOSAFACTER II code from the DLC-80/DRALIST library of radioactive decay data for approximately 500 nuclides

Effect of low dose gamma irradiation on onion yield: Large scale application

International Nuclear Information System (INIS)

Al-Oudat, M.

1993-01-01

Large scale application of presowing gamma-irradiation of seeds, bulblets and bulbs of onion, performed in 1989, using the doses of 10 Gy for seeds and 1 Gy for bulblets and bulbs. The doses were chosen on the basis of previous experiments. Reliable increases in yield of seeds (19.3%), bulblets (18.9) and bulbs (31.4%) for red variety. and of 22.3% and 23.4% for seeds and bulbs of white variety were obtained. (author). 2 tabs

Theory of thermoluminescence gamma dose response: The unified interaction model

International Nuclear Information System (INIS)

Horowitz, Y.S.

2001-01-01

We describe the development of a comprehensive theory of thermoluminescence (TL) dose response, the unified interaction model (UNIM). The UNIM is based on both radiation absorption stage and recombination stage mechanisms and can describe dose response for heavy charged particles (in the framework of the extended track interaction model - ETIM) as well as for isotropically ionising gamma rays and electrons (in the framework of the TC/LC geminate recombination model) in a unified and self-consistent conceptual and mathematical formalism. A theory of optical absorption dose response is also incorporated in the UNIM to describe the radiation absorption stage. The UNIM is applied to the dose response supralinearity characteristics of LiF:Mg,Ti and is especially and uniquely successful in explaining the ionisation density dependence of the supralinearity of composite peak 5 in TLD-100. The UNIM is demonstrated to be capable of explaining either qualitatively or quantitatively all of the major features of TL dose response with many of the variable parameters of the model strongly constrained by ancilliary optical absorption and sensitisation measurements

Two Dimensional Verification of the Dose Distribution of Gamma Knife Model C using Monte Carlo Simulation with a Virtual Source

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae-Hoon; Kim, Yong-Kyun; Lee, Cheol Ho; Son, Jaebum; Lee, Sangmin; Kim, Dong Geon; Choi, Joonbum; Jang, Jae Yeong [Hanyang University, Seoul (Korea, Republic of); Chung, Hyun-Tai [Seoul National University, Seoul (Korea, Republic of)

2016-10-15

Gamma Knife model C contains 201 {sup 60}Co sources located on a spherical surface, so that each beam is concentrated on the center of the sphere. In the last work, we simulated the Gamma Knife model C through Monte Carlo simulation code using Geant4. Instead of 201 multi-collimation system, we made one single collimation system that collects source parameter passing through the collimator helmet. Using the virtual source, we drastically reduced the simulation time to transport 201 gamma circle beams to the target. Gamma index has been widely used to compare two dose distributions in cancer radiotherapy. Gamma index pass rates were compared in two calculated results using the virtual source method and the original method and measured results obtained using radiocrhomic films. A virtual source method significantly reduces simulation time of a Gamma Knife Model C and provides equivalent absorbed dose distributions as that of the original method showing Gamma Index pass rate close to 100% under 1mm/3% criteria. On the other hand, it gives a little narrow dose distribution compared to the film measurement showing Gamma Index pass rate of 94%. More accurate and sophisticated examination on the accuracy of the simulation and film measurement is necessary.

Influence of dose on particle size of colloidal silver nanoparticles synthesized by gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Naghavi, Kazem, E-mail: Kazem.naghavi@gmail.co [Universiti Putra Malaysia, Physics Department, 43400 UPM SERDANG, Selangor (Malaysia); Saion, Elias [Universiti Putra Malaysia, Physics Department, 43400 UPM SERDANG, Selangor (Malaysia); Rezaee, Khadijeh [Department of Nuclear Engineering, Faculty of Modern Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Yunus, Wan Mahmood Mat [Universiti Putra Malaysia, Physics Department, 43400 UPM SERDANG, Selangor (Malaysia)

2010-12-15

Colloidal silver nanoparticles were synthesized by {gamma}-irradiation-induced reduction method of an aqueous solution containing silver nitrate as a precursor in various concentrations between 7.40x10{sup -4} and 1.84x10{sup -3} M, polyvinyl pyrrolidone for capping colloidal nanoparticles, isopropanol as radical scavenger of hydroxyl radicals and deionised water as a solvent. The irradiations were carried out in a {sup 60}Co {gamma} source chamber at doses up to 70 kGy. The optical absorption spectra were measured using UV-vis spectrophotometer and used to study the particle distribution and electronic structure of silver nanoparticles. As the radiation dose increases from 10 to 70 kGy, the absorption intensity increases with increasing dose. The absorption peak {lambda}{sub max} blue shifted from 410 to 403 nm correspond to the increase of absorption conduction electron energy from 3.02 to 3.08 eV, indicating the particle size decreases with increasing dose. The particle size was determined by photon cross correlation spectroscopy and the results showed that the particle diameter decreases exponentially with the increase of dose. The transmission electron microscopy images were taken at doses of 20 and 60 kGy and the results confirmed that as the dose increases the diameter of colloidal silver nanoparticle decreases and the particle distribution increases.

[Induction of glutathione and activation of immune functions by low-dose, whole-body irradiation with gamma-rays].

Science.gov (United States)

Kojima, Shuji

2006-10-01

We first examined the relation between the induction of glutathione and immune functions in mice after low-dose gamma-ray irradiation. Thereafter, inhibition of tumor growth by radiation was confirmed in Ehrlich solid tumor (EST)-bearing mice. The total glutathione level of the splenocytes transiently increased soon after irradiation and reached a maximum at around 4 h postirradiation. Thereafter, the level reverted to the 0 h value by 24 h postirradiation. A significantly high splenocyte proliferative response was also recognized 4 h postirradiation. Natural killer (NK) activity was also increased significantly in a similar manner. The time at which the response reached the maximum coincided well with that of maximum total glutathione levels of the splenocytes in the gamma-ray-irradiated mice. Reduced glutathione exogenously added to splenocytes obtained from normal mice enhanced the proliferative response and NK activity in a dose-dependent manner. The inhibitory effects of radiation on tumor growth was then examined in EST-bearing mice. Repeated low-dose irradiation (0.5 Gy, four times, before and within an early time after inoculation) significantly delayed the tumor growth. Finally, the effect of single low-dose (0.5 Gy), whole-body gamma-ray irradiation on immune balance was examined to elucidate the mechanism underlying the antitumor immunity. The percentage of B cells in blood lymphocytes was selectively decreased after radiation, concomitant with an increase in that of the helper T cell population. The IFN-gamma level in splenocyte culture prepared from EST-bearing mice was significantly increased 48 h after radiation, although the level of IL-4 was unchanged. IL-12 secretion from macrophages was also enhanced by radiation. These results suggest that low-dose gamma-rays induce Th1 polarization and enhance the activities of tumoricidal effector cells, leading to an inhibition of tumor growth.

Effects of sublethal doses of gamma radiation on the developing rat brain

International Nuclear Information System (INIS)

Cerda, H.; Carlsson, J.; Larsson, B.; Saefwenberg, J.O.

1975-01-01

Newborn rats were irradiated with 60 Co gamma rays. Doses of 0, 80 or 160 rads were given to the whole body. The whole body and brain weights, DNA and RNA contents of the brain and 3 H-thymidine or 3 H-uridine incorporated by the brain were measured at 5, 10 or 15 days after birth. A dose of 160 rads produced clear alterations in the brain but no clear effects could be detected when 80 rads were given. (author)

Sterilization and lethal gamma radiation doses on adults and eggs of Sitotroga Cerealella (OLIVIER)

International Nuclear Information System (INIS)

Wiendl, F.M.; Bovi, O.A.; Arthur, V.

1975-04-01

The influence of lethal doses of radiation from a cobalt 60 gamma source on eggs, adults and fertitility of Sitotroga Cerealella (Olivier) is described. Eggs irradiated with a dose of 14 Krad still showed viability of 16.1%. On longevity doses up to 70 Krad were usually non lethal but some variation could be observed related to the larval diet. Females fertilized by males irradiated with a dose of 70 Krad produced 36% fertile eggs. When the females were irradiated with the same dose, their fertility dropped to 2.2% and when both sexes were irradiated with a 60 Krad dose, the fertility was 28.8%

Sterilization of boll weevil pupae with fractionated doses of gamma irradiation

International Nuclear Information System (INIS)

Haynes, J.W.; Mitlin, N.; Davich, T.B.; Dawson, J.R.; McGovern, W.L.; McKibben, G.H.

1977-01-01

Fractionated doses of 6,250-8,000 rads of gamma irradiation administered to pupae of the boll weevil, Anthonomus grandis Boh., sexually sterilized both sexes. Mortality of males thus treated with 6,250 and 8,000 rads via fractionation was 14% and 27% respectively, by 5 days posttreatment compared with 46% mortality when an equivalent acute dose was administered to newly emerged adults. Pheromone production of males irradiated at 6,250 rads was one-third that of the control for the first 4 days, but equal that of the control during 5-11 days posttreatment. This procedure lends itself to the large-scale sterilization of weevils needed in an eradication program. This technique is applicable to other insects that are highly susceptible to acute doses

Reduction in flatulence factors in mung beans (Vigna radiata) using low-dose gamma-irradiation

International Nuclear Information System (INIS)

Machaiah, J.P.; Pednekar, M.D.; Thomas, P.

1999-01-01

Mungbeans (Vigna radiata), control and gamma-irradiated at insect disinfestation dose levels (0.25 and 0.75 kGy) were germinated (0-6 Bays) and the qualitative and quantitative changes in soluble carbohydrates were studied in detail. The key flatulence-producing raffinose family oligosaccharides inmungbeans were degraded in the irradiated samples at the onset of the germination (0-2 days) compared to the control where it occurred much later (>4days). However, the reducing sugars, mainly glucose, fructose and galactose, which are metabolised easily, were enhanced in the irradiated samples. At low dose (0.25 kGy), irradiation had no effect on germination and sprout length, indicating that irradiated beans are suitable for use as sprouted beans. These observations clearly indicate that gamma-irradiation at insect disinfestation dose levels improved the digestibility and nutritional quality of mung beans by reducing the content of oligosaccharides responsible for intestinal gas production. (C) 1999 Society of Chemical Industry

Tumor induction in mice after local irradiation with single doses of either carbon-ion beams or gamma rays.

Science.gov (United States)

Ando, Koichi; Koike, Sachiko; Ohmachi, Yasushi; Ando, Yutaka; Kobashi, Gen

2014-12-01

To determine the dose-dependent relative biological effectiveness (RBE) for tumor prevalence in mice receiving single localized doses to their right leg of either carbon ions (15, 45 or 75 keV/μm) or 137Cs gamma rays. A total of 1647 female C3H mice were irradiated to their hind legs with a localized dose of either reference gamma rays or 15, 45 or 75 keV/μm carbon-ion beams. Irradiated mice were evaluated for tumors twice a month during their three-year life span, and the dimensions of any tumors found were measured with a caliper. The tumor induction frequency was calculated by Kaplan-Meier analysis. The incidence of tumors from 50 Gy of 45 keV/μm carbon ions was marginally higher than those from 50 Gy of gamma rays. However, 60 Gy of 15 keV/μm carbon ions induced significantly fewer tumors than did gamma rays. RBE values of 0.87 + 0.12, 1.29 + 0.08 or 2.06 + 0.39 for lifetime tumorigenesis were calculated for 15, 45 or 75 keV/μm carbon-ion beams, respectively. Fibrosarcoma predominated, with no Linear Energy Transfer (LET)-dependent differences in the tumor histology. Experiments measuring the late effect of leg skin shrinkage suggested that the carcinogenic damage of 15 keV/μm carbon ions would be less than that of gamma rays. We conclude that patients receiving radiation doses to their normal tissues would face less risk of secondary tumor induction by carbon ions of intermediate LET values compared to equivalent doses of photons.

Effect of low gamma-ray doses and seeding rates on growth, yield and its components as well as seed quality of lentils (lens Culinaries, med.)

International Nuclear Information System (INIS)

Dprgham, E.A.

1999-01-01

To study the effect of low doses gamma-rays and seeding rates on growth, yield and its components as well as seed quality, two experiments were conducted during 1993/1994 and 1994/1995 seasons. Each experiment included treatments which were the combinations of three levels of seeding rates (45,60 and 75kg/fed.) and four doses of gamma-rays (15, 25,35 and 45(Gy). The effect of interaction between seeding rates and gamma doses on growth characters was not significant whereas there was a tendency for improvement of growth characters by increasing gamma doses up to 45 Gy. Different gamma doses caused marked increase for lintil's yield components except the number of seeds/plant while high seeding rates (60 and 75 Kg/fed) reduced significantly the number of pods/plant and number of seeds/plant. For yield, various gamma doses showed significant increase for seed straw yield as compared to the control. However, seeding rates of 60 and 75 kg/fed increased significantly seed and straw yield as compared with the seeding rate of 45 kg/fed (control)

Assessment of background gamma radiation levels using airborne gamma ray spectrometer data over uranium deposits, Cuddapah Basin, India - A comparative study of dose rates estimated by AGRS and PGRS.

Science.gov (United States)

Srinivas, D; Ramesh Babu, V; Patra, I; Tripathi, Shailesh; Ramayya, M S; Chaturvedi, A K

2017-02-01

The Atomic Minerals Directorate for Exploration and Research (AMD) has conducted high-resolution airborne gamma ray spectrometer (AGRS), magnetometer and time domain electromagnetic (TDEM) surveys for uranium exploration, along the northern margins of Cuddapah Basin. The survey area includes well known uranium deposits such as Lambapur-Peddagattu, Chitrial and Koppunuru. The AGRS data collected for uranium exploration is utilised for estimating the average absorbed rates in air due to radio-elemental (potassium in %, uranium and thorium in ppm) distribution over these known deposit areas. Further, portable gamma ray spectrometer (PGRS) was used to acquire data over two nearby locations one from Lambapur deposit, and the other from known anomalous zone and subsequently average gamma dose rates were estimated. Representative in-situ rock samples were also collected from these two areas and subjected to radio-elemental concentration analysis by gamma ray spectrometer (GRS) in the laboratory and then dose rates were estimated. Analyses of these three sets of results complement one another, thereby providing a comprehensive picture of the radiation environment over these deposits. The average absorbed area wise dose rate level is estimated to be 130 ± 47 nGy h -1 in Lambapur-Peddagattu, 186 ± 77 nGy h -1 in Chitrial and 63 ± 22 nGy h -1 in Koppunuru. The obtained average dose levels are found to be higher than the world average value of 54 nGy h -1 . The gamma absorbed dose rates in nGy h -1 were converted to annual effective dose rates in mSv y -1 as proposed by the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). The annual average effective dose rates for the entire surveyed area is 0.12 mSv y -1 , which is much lower than the recommended limit of 1 mSv y -1 by International Commission on Radiation protection (ICRP). It may be ascertained here that the present study establishes a reference data set (baseline) in these areas

Natural radioactivity in some building materials in Cuba and their contribution to the indoor gamma dose rate

Energy Technology Data Exchange (ETDEWEB)

Brigido Flores, Osvaldo; Barreras Caballero, Aldo A.; Montalvan Estrada, Alberto; Queipo Garcia, Maite [Ministerio de Ciencia, Tecnologia y Medio Ambiente, Camaguey (Cuba). Centro de Atencion a la Actividad Nuclear. Lab. de Vigilancia Radiologica Ambiental]. E-mail: sean@caonao.cmw.inf.cu; Zerquera, Juan Tomas [Ministerio de Ciencia, Tecnologia y Medio Ambiente, La Habana (Cuba). Agencia de Energia Nuclear. Centro de Proteccion y Higiene de las Radiaciones

2001-07-01

The natural radioactivity of some building materials commonly used in Cuba was measured by gamma spectrometry. Typical concentrations, so far encountered, are in the ranges: 47 to 2511 Bq.kg{sup -1} for {sup 40} K; 9 to 71 Bq.kg{sup -1} for {sup 226} Ra; and 2 to 38 Bq.kg{sup -1} for {sup 232} Th. The external gamma ray absorbed doses in indoor air, and the corresponding effective dose equivalents in a typical dwelling are presented in this work. (author)

Evaluation of absorbed dose-distribution in the X-ray or gamma-irradiator for blood products

International Nuclear Information System (INIS)

Moriyama, Satoshi; Kurihara, Katsuhiko; Yokokawa, Nobuhiko; Satake, Masahiro; Juji, Takeo

2001-01-01

Irradiation of blood products abrogates the proliferation of lymphocytes present in cellular component, which is currently the only accepted methodology to prevent transfusion-associated graft versus host disease (TA-GVHD). A range of irradiation dose levels between 15 Gy and 50 Gy is being used, but the majority of facilities are employing 15 Gy. It should, however, be recognized that the delivered dose in the instrument canister might differ from the actual dose absorbed by the blood bag. This study have evaluated the actual dose distribution under practical conditions where a container was loaded with blood products or water bags, or filled with distilled water. This approach provides data that the maximum attenuation occurred when the container was completely filled with a blood-compatible material. Thus, an error of approximately 20 percent should be considered in the dose measured in the in-air condition. A dose calibration in an in-air condition may lead to substantial underexposure of the blood products. A dose distribution study using adequately prearranged exposure period verified that the absorbed dose of 15 Gy was attained at any point in the container for both linear accelerator and gamma-irradiator. The maximal difference in the absorbed dose between measured points was 1.5- and 1.6-fold for linear accelerator and gamma-irradiator, respectively. In conclusion, using blood-compatible materials, a careful dose calibration study should be employed in which the absorbed dose of 15 Gy is obtained at the point where the lowest dose could be expected. (author)

Protective and Therapeutic Role of Low Dose Gamma Radiation on Streptozotocin Induced Diabetes in Rats

International Nuclear Information System (INIS)

Mansour, H.H.; Hafez, H.F.; Shouman, S.A.

2011-01-01

Diabetes mellitus is a multi-factorial disease which is characterized by vascular and renal complication. This study was initiated to investigate the protective and the therapeutic effect of low dose of gamma radiation (LDR) on diabetic complications. A total of 30 adult male rats were divided into 5 groups: Group I: served as control and injected intraperitoneally with 0.2 ml of 0.1 mol/l citrate buffer (ph 4.5), group II: rats became diabetic via intraperitoneal injection with 60 mg/kg streptozotocin (STZ) dissolved in 0.2 ml of 0.1 mol/l citrate buffer (ph 4.5), group III irradiated rats (IRR): submitted to fractionated dose of whole body gamma rays; 0.25 Gy for 2 consecutive days (whole dose 0.5 Gy), group IV diabetic irradiated rats (STZ + IRR): rats became diabetic as group II then four weeks after diabetes induction (day 28), rats were submitted to 2 fractions of whole body gamma rays as in group III, and group V irradiated diabetic rats (IRR + STZ): rats were injected intraperitoneally with 0.2 ml of 0.1 mol/l citrate buffer then submitted to whole body gamma rays; 0.25 Gy for 2 consecutive days then one hour after the last IRR dose, rats were made diabetic as group II. In pre and post-irradiation of STZ rats, significant changes were observed in serum lipid profiles, hepatic and cardiac serum enzymes. Significant decrease in hepatic and cardiac malondialdehyde (MDA) and total nitrate/nitrite (NO(x)) levels, and significant increase in superoxide dismutase (SOD) and glutathione (GSH) levels were observed as compared to diabetic group. The study suggests that LDR may provide useful protective and therapeutic option in the reversal of oxidative stress induced in diabetic rats

Measurement of neutron and gamma absorbed doses in phantoms exposed to mixed fields

International Nuclear Information System (INIS)

Beraud-Sudreau, E.; Lemaire, G.; Maas, J.

1985-01-01

In order to study the dosimetric characteristics of PIN junctions, the absorbed doses measured by junctions and FLi7 in air and water phantoms were compared with the doses measured by classical neutron dosimetry in mixed fields. The validity of the experimental responses of PIN junctions being thus checked and established, neutron and gamma dose distributions in tissue equivalent plastic phantoms (plastinaut) and mammals (piglets) were evaluated as well as the absorbed dose distributions in the pig bone-marrow producing areas. By using correlatively a Monte-Carlo calculation method and applying some simplifying assumptions, the absorbed doses were derived from the spectrum of SILENE's neutrons at various depths inside a cubic water phantom and the results were compared with some from the literature [fr

Influence of high-dose gamma radiation and particle size on antioxidant properties of Maize ( Zea mays L.) flour

International Nuclear Information System (INIS)

Nawaz, Haq; Shad, Muhammad Aslam; Rehman, Tanzila; Ramzan, Ayesha

2016-01-01

Influence of high-dose gamma radiation and particle size on antioxidant properties of maize (Zea mays L.) flour was studied using response surface methodology. A central composite design based on three levels of each of particle size, in terms of mesh number (40, 60 and 80 meshes), and gamma radiation dose (25, 50 and 75 kGy) was constructed. A statistically significant dose-dependent decrease (p<0.05) in antioxidant properties of gamma irradiated flour was observed. However, an increase in the mesh number (decrease in particle size of flour) resulted in an increase in antioxidant properties. The optimum level of radiation dose to achieve maximum value of responses was found to be 50 kGy for Trolox equivalent total antioxidant activity (TETAOA), 25 kGy for iron chelating ability (ICA), 25 kGy for reducing power (RP) and 75 kGy for linoleic acid reduction capacity (LARC). However, the optimum level of mesh number to achieve desired levels of TETAOA, ICA, RP and LARC was found to be 80 meshes. (author)

Influence of high-dose gamma radiation and particle size on antioxidant properties of Maize ( Zea mays L.) flour

Energy Technology Data Exchange (ETDEWEB)

Nawaz, Haq; Shad, Muhammad Aslam; Rehman, Tanzila; Ramzan, Ayesha, E-mail: haqnawaz@bzu.edu.pk [Bahauddin Zakariya University, Multan (Pakistan)

2016-10-15

Influence of high-dose gamma radiation and particle size on antioxidant properties of maize (Zea mays L.) flour was studied using response surface methodology. A central composite design based on three levels of each of particle size, in terms of mesh number (40, 60 and 80 meshes), and gamma radiation dose (25, 50 and 75 kGy) was constructed. A statistically significant dose-dependent decrease (p<0.05) in antioxidant properties of gamma irradiated flour was observed. However, an increase in the mesh number (decrease in particle size of flour) resulted in an increase in antioxidant properties. The optimum level of radiation dose to achieve maximum value of responses was found to be 50 kGy for Trolox equivalent total antioxidant activity (TETAOA), 25 kGy for iron chelating ability (ICA), 25 kGy for reducing power (RP) and 75 kGy for linoleic acid reduction capacity (LARC). However, the optimum level of mesh number to achieve desired levels of TETAOA, ICA, RP and LARC was found to be 80 meshes. (author)

Influence of low dose {gamma} radiation on the dormancy, growth and physiological activity of seed potato (solanum tuberosum L.)

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Lee, Y. K.; Lee, H. Y.; Baek, M. H.; Yoo, Z. C. [KAERI, Taejon (Korea, Republic of)

2002-05-01

To observe the stimulating effect of low dose {gamma} radiation on the dormancy breaking and growth of potato with different storage duration and conditions, potato were irradiated with the dose of 1 {approx} 16 Gy. Though varied with storage duration and conditions, sprouting rate of potato stored at 5 .deg. C in the dark was promoted at the 8 and 16 Gy irradiation group compared to 20 .deg. C in the light. The field growth of potato stored at 5 .deg. C in the dark was highly increased at the 2, 4, 8 Gy irradiation group. The CAT activity of potato was increased by about 20% at 1,8 and 16 Gy irradiation group. POD activity was also increased by 7 {approx} 16% at 1, 8 and 16 Gy irradiation group compared to the control. Fv/Fm was not changed by the low dose {gamma} radiation. However, the effective quantum yield of PSII was slightly increased by about 12% at 1 and 16 Gy irradiation group. Seedling irradiated with low dose {gamma} radiation showed the lower excitation pressure on PSII (1- {sub q}P), while NPQ was greatly increased by 45% at 4 Gy irradiation group. These results clearly showed the positive effect of low dose {gamma} radiation on the seedling growth of potato via increasing photoprotective capacities of photosynthetic apparatus.

Novel Concrete Chemistry Achieved with Low Dose Gamma Radiation Curing and Resistance to Neutron Activation

Science.gov (United States)

Burnham, Steven Robert

As much as 50% of ageing-related problems with concrete structures can be attributed to con-struction deficiencies at the time of placement. The most influential time affecting longevity of concrete structures is the curing phase, or commonly the initial 28 days following its placement. A novel advanced atomistic analysis of novel concrete chemistry is presented in this dissertation with the objective to improve concrete structural properties and its longevity. Based on experiments and computational models, this novel concrete chemistry is discussed in two cases: (a) concrete chemistry changes when exposed to low-dose gamma radiation in its early curing stage, thus improving its strength in a shorter period of time then curing for the conventional 28 days; (b) concrete chemistry is controlled by its atomistic components to assure strength is not reduced but that its activation due to long-term exposure to neutron flux in nuclear power plants is negligible. High dose gamma radiation is well documented as a degradation mechanism that decreases concrete's compressive strength; however, the effects of low-dose gamma radiation on the initial curing phase of concrete, having never been studied before, proved its compressive strength increases. Using a 137 Cs source, concrete samples were subjected to gamma radiation during the initial curing phase for seven, 14, and 28 days. The compressive strength after seven days is improved for gamma cured concrete by 24% and after 14 days by 76%. Concrete shows no improvement in compressive strength after 28 days of exposure to gamma radiation, showing that there is a threshold effect. Scanning Electron Microscopy is used to examine the microstructure of low-dose gamma radiation where no damage to its microstructure is found, showing no difference between gamma cured and conventionally cured concrete. Molecular dynamics modeling based on the MOPAC package is used to study how gamma radiation during the curing stage improves

Effect of low-doses gamma radiation on physico-chemical properties of cereal starches

International Nuclear Information System (INIS)

Gambus, H.; Juszczak, L.; Achremowicz, B.

1995-01-01

Wheat starch of Emika variety was treated with 3 and 5 kGy doses of gamma radiation, rye starch of Dankowskie Zlote variety and triticale starch of Dagro variety - with 3 kGy doses. Radiation of this starch caused an increase of reduction ability and water solubility at 60 and 80 o C. However with the increased radiation doses a significant decrease of maximum viscosity and of the viscosity of starch pastes being cooled to 50% was observed. Mild radiopolimerization also decreased the degree of retrogradation of wheat and rye starch pastes stored at above 0 o C. (author)

Gamma dose assessment to the environment of uraniferous area - Case of Vinaninkarena

International Nuclear Information System (INIS)

Andriamarojaona, A.A.

2014-01-01

Madagascar has several old abandoned uranium sites. Mining exploitations have been undertaken as the case of uranium in sedimentary formation of Vinaninkarena. After its exploitation, it still presents risks. The mine can cause harmful effects to human health and the environment. This work concerns especially the gamma dose assessment, identification of existing radionuclides gamma emitters and measurements of contamination level of the mine. The obtained results were compared with the standards fixed by the regulatory body and International Reference. In order to protect the public and the environment against the harmful effect of ionizing radiation around the sites, the proposed recommendations should be applied and respected. [fr

Intercomparison of personnel dosimetry for thermal neutron dose equivalent in neutron and gamma-ray mixed fields

International Nuclear Information System (INIS)

Ogawa, Yoshihiro

1985-01-01

In order to consider the problems concerned with personnel dosimetry using film badges and TLDs, an intercomparison of personnel dosimetry, especially dose equivalent responses of personnel dosimeters to thermal neutron, was carried out in five different neutron and gamma-ray mixed fields at KUR and UTR-KINKI from the practical point of view. For the estimation of thermal neutron dose equivalent, it may be concluded that each personnel dosimeter has good performances in the precision, that is, the standard deviations in the measured values by individual dosimeter were within 24 %, and the dose equivalent responses to thermal neutron were almost independent on cadmium ratio and gamma-ray contamination. However, the relative thermal neutron dose equivalent of individual dosimeter normalized to the ICRP recommended value varied considerably and a difference of about 4 times was observed among the dosimeters. From the results obtained, it is suggested that the standardization of calibration factors and procedures is required from the practical point of radiation protection and safety. (author)

Effects of differents gamma radiation doses absorbed for postharvest tomato fruits

International Nuclear Information System (INIS)

Silva Abreu, Toneypson da; Jesus, Edgar F.O. de; Soares, Antonio G.

1997-01-01

Postharvest tomato fuits Santa Cruz were submitted to prestorage gamma irradiation treatment with different doses range zero (unirradiated fruits) to 1000 Gy. The aim of this study is to evaluate the postharvest quality parameters: Hunter colour values for light transmittance analysis, pH, total titratable acidity, total soluble solids, maximum firmness and maturity stage. The fruits were stored under (25±1) 0 C with (93±3) relative humidity. The results obtained from the different irradiated treatments showed 600 Gy as the best dose to increase the shelf-life of tomato fruits and to decay its ripening. (author). 5 refs., 12 figs., 1 tab

Assessment of Annual Effective Dose for Natural Radioactivity of Gamma Emitters in Biscuit Samples in Iraq.

Science.gov (United States)

Abojassim, Ali Abid; Al-Alasadi, Lubna A; Shitake, Ahmed R; Al-Tememie, Faeq A; Husain, Afnan A

2015-09-01

Biscuits are an important type of food, widely consumed by babies in Iraq and other countries. This work uses gamma spectroscopy to measure the natural radioactivity due to long-lived gamma emitters in children's biscuits; it also estimates radiation hazard indices, that is, the radium equivalent activity, the representative of gamma level index, the internal hazard index, and the annual effective dose in children. Ten samples were collected from the Iraqi market from different countries of origin. The average specific activities for (226)Ra, (232)Th, and (40)K were 9.390, 3.1213, and 214.969 Bq/kg, respectively, but the average of the radium equivalent activity and the internal hazard index were 33.101 Bq/kg and 0.107, respectively. The total average annual effective dose from consumption by adults, children, and infants is estimated to be 0.655, 1.009, and 0.875 mSv, respectively. The values found for specific activity, radiation hazard indices, and annual effective dose in all samples in this study were lower than worldwide median values for all groups; therefore, these values are found to be safe.

Influence of gamma dose rate on longevity of Laemophloeus ferrugineus (STEPH.)

International Nuclear Information System (INIS)

Wiendl, F.M.; Tornisielo, V.L.

1975-12-01

Insects of the species Laemophloeus ferrugineus (Steph.) were irradiated with different gamma dose rates from a radial type Co-60 source. The rates utilized were 59580, 15750, 2750, 632, 154 and 63 rad/hour, respectively at 10, 20, 50, 100, 200 and 300 cm from the source. The insects were irradiated with a dose of 15000 rad. Death rate was checked every 7 days; starting from these numbers, life expectancy was estimated for each week in relation to respective dose rate. The following results were obtained for insects life expectancy estimates upon beginning of the experiment: 85.63 days (control); 19.50 (10 cm); 19.40 (20 cm); 20.40 (50 cm); 22.23 (100 cm); 22.00 (200 cm) and 23.11 (300 cm). The number of days until the last individuals of each dose rate died was also registered: 248 days (control); 31 (10 cm); 31 (20 cm); 31 (50 cm); 185 (100 cm); 164 (200 cm) and 143 (300 cm)

Activation of the JET vacuum vessel: a comparison of calculated with measured gamma-radiation fluxes and dose rates

International Nuclear Information System (INIS)

Jarvis, O.N.; Sadler, G.; Avery, A.; Verschuur, K.A.

1988-01-01

The gamma-radiation dose-rates inside the JET vacuum vessel due to induced radioactivity were measured at intervals throughout the 1986 period of operation, and the decay gamma energy spectrum was measured during the subsequent lengthy shutdown. The dose-rates were found to be in good agreement with values calculated using the neutron yield records compiled from the time-resolved neutron yield monitor responses for individual discharges. This result provides strong support for the reliability of the neutron yield monitor calibration. (author)

SU-F-T-266: Dynalogs Based Evaluation of Different Dose Rate IMRT Using DVH and Gamma Index

Energy Technology Data Exchange (ETDEWEB)

Ahmed, S [Aga Khan University Hospital, Karachi, Sindh (Pakistan); Ahmed, S [Pakistan Inst of Eng Applied Sciences, Islamabad (Pakistan); Ahmed, F; Hussain, A

2016-06-15

Purpose: This work investigates the impact of low and high dose rate on IMRT through Dynalogs by evaluating Gamma Index and Dose Volume Histogram. Methods: The Eclipse™ treatment planning software was used to generate plans on prostate and head and neck sites. A range of dose rates 300 MU/min and 600 MU/min were applied to each plan in order to investigate their effect on the beam ON time, efficiency and accuracy. Each plan had distinct monitor units per fraction, delivery time, mean dose rate and leaf speed. The DVH data was used in the assessment of the conformity and plan quality.The treatments were delivered on Varian™ Clinac 2100C accelerator equipped with 120 leaf millennium MLC. Dynalogs of each plan were analyzed by MATLAB™ program. Fluence measurements were performed using the Sun Nuclear™ 2D diode array and results were assessed, based on Gamma analysis of dose fluence maps, beam delivery statistics and Dynalogs data. Results: Minor differences found by adjusted R-squared analysis of DVH’s for all the plans with different dose rates. It has been also found that more and larger fields have greater time reduction at high dose rate and there was a sharp decrease in number of control points observed in dynalog files by switching dose rate from 300 MU/min to 600 MU/min. Gamma Analysis of all plans passes the confidence limit of ≥95% with greater number of passing points in 300 MU/min dose rate plans. Conclusion: The dynalog files are compatible tool for software based IMRT QA. It can work perfectly parallel to measurement based QA setup and stand-by procedure for pre and post delivery of treatment plan.

SU-F-T-266: Dynalogs Based Evaluation of Different Dose Rate IMRT Using DVH and Gamma Index

International Nuclear Information System (INIS)

Ahmed, S; Ahmed, S; Ahmed, F; Hussain, A

2016-01-01

Purpose: This work investigates the impact of low and high dose rate on IMRT through Dynalogs by evaluating Gamma Index and Dose Volume Histogram. Methods: The Eclipse™ treatment planning software was used to generate plans on prostate and head and neck sites. A range of dose rates 300 MU/min and 600 MU/min were applied to each plan in order to investigate their effect on the beam ON time, efficiency and accuracy. Each plan had distinct monitor units per fraction, delivery time, mean dose rate and leaf speed. The DVH data was used in the assessment of the conformity and plan quality.The treatments were delivered on Varian™ Clinac 2100C accelerator equipped with 120 leaf millennium MLC. Dynalogs of each plan were analyzed by MATLAB™ program. Fluence measurements were performed using the Sun Nuclear™ 2D diode array and results were assessed, based on Gamma analysis of dose fluence maps, beam delivery statistics and Dynalogs data. Results: Minor differences found by adjusted R-squared analysis of DVH’s for all the plans with different dose rates. It has been also found that more and larger fields have greater time reduction at high dose rate and there was a sharp decrease in number of control points observed in dynalog files by switching dose rate from 300 MU/min to 600 MU/min. Gamma Analysis of all plans passes the confidence limit of ≥95% with greater number of passing points in 300 MU/min dose rate plans. Conclusion: The dynalog files are compatible tool for software based IMRT QA. It can work perfectly parallel to measurement based QA setup and stand-by procedure for pre and post delivery of treatment plan.

Simple approximation for estimating centerline gamma absorbed dose rates due to a continuous Gaussian plume

International Nuclear Information System (INIS)

Overcamp, T.J.; Fjeld, R.A.

1987-01-01

A simple approximation for estimating the centerline gamma absorbed dose rates due to a continuous Gaussian plume was developed. To simplify the integration of the dose integral, this approach makes use of the Gaussian cloud concentration distribution. The solution is expressed in terms of the I1 and I2 integrals which were developed for estimating long-term dose due to a sector-averaged Gaussian plume. Estimates of tissue absorbed dose rates for the new approach and for the uniform cloud model were compared to numerical integration of the dose integral over a Gaussian plume distribution

The Measuring of the Gamma Dose Rate in the Air at Location of the Sar-Mountain

International Nuclear Information System (INIS)

Adrovic, F.; Ninkovic, M.; Adrovic, S.

1999-01-01

The results of the measured values of gamma dose rate in the air at the location of Sar-mountain (Balkan Peninsula) using autonomous ADL-probe Gamma Tracer system. The difference between levels of the natural background radiation and natural environment has been pointed out at the different chosen measuring overall research of natural radioactivity at the location of Sar-mountain

Comparison of gamma knife validation film's analysis results of different film dose analysis software

International Nuclear Information System (INIS)

Cheng Xiaojun; Zhang Conghua; Liu Han; Dai Fuyou; Hu Chuanpeng; Liu Cheng; Yao Zhongfu

2011-01-01

Objective: To compare the analytical result of different kinds of film dose analysis software for the same gamma knife, analyze the reasons of difference caused, and explore the measurements and means for quality control and quality assurance during testing gamma knife and analyzing its result. Methods: To test the Moon Deity gamma knife with Kodak EDR2 film and γ-Star gamma knife with GAFCHROMIC® EBT film, respectively. All the validation films are scanned to proper imagine format for dose analysis software by EPSON PERFECTION V750 PRO scanner. Then imagines of Moon Deity gamma knife are analyzed with Robot Knife Adjuvant 1.09 and Fas-09 1.0, and imagines of γ-Star gamma knife with Fas-09 and MATLAB 7.0. Results: There is no significant difference in the maximum deviation of radiation field size (Full Width at Half Maximum, FWHM) and its nominal value between Robot Knife Adjuvant and Fas-09 for Moon Deity gamma knife (t=-2.133, P>0.05). The analysis on the radiation field's penumbra region width of collimators which have different sizes indicated that the differences are significant (t=-8.154, P<0.05). There is no significant difference in the maximum deviation of FWHM and its nominal value between Fas-09 and MATLAB for γ-Star gamma knife (t=-1.384, P>0.05). However, following national standards,analysis of φ4 mm width of collimators can obtain different results according to the two kinds software, and the result of Fas-09 is not qualified while MATLAB is qualified. The analysis on the radiation field's penumbra region width of collimators which have different sizes indicates that the differences are significant (t=3.074, P<0.05). The imagines are processed with Fas-09. The analysis of imagine in the pre-and the post-processing indicates that there is no significant difference in the maximum deviation of FWHM and its nominal value (t=0.647, P>0.05), and the analytical result of the radiation field's penumbra region width indicates that there is

Effect of dose fractionation of 60Co gamma radiation on longevity and reproduction of Sitophilus granarius (L., 1785) (Col., Curculionidae) in wheat

International Nuclear Information System (INIS)

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

1987-01-01

The effects of fractionated doses of gamma radiation in different interval of time on longevity and reproductivity of Sitophilus granarius (L., 1785) are studied. Gamma radiation was provided at dose rate of 1.56 kGy/hour by a Cobalt 60 source (Gammabeam-650). The insects were divided in two sets: one was irradiated at acute doses and the other in fractionated doses, with interval of 48 hours. Both sets received doses of 0,40, 50, 60, 70, 80, 90 and 100Gy. Mortality and and emergency were determined weekly. (M.A.C.) [pt

Determination of Proton dose distal fall-off location by detecting right-angled prompt gamma rays

International Nuclear Information System (INIS)

Seo, Kyu Seok

2006-02-01

The proton beam has a unique advantage over the electron and photon beams in that it can give very high radiation dose to the tumor volume while effectively sparing the neighboring healthy tissue and organs. The number of proton therapy facility is very rapidly increasing in the world. And now the 230 MeV cyclotron facility for proton therapy is constructing at National Cancer Center, this facility until 2006. The distal fall-off location of proton beam is simply calculated by analytical method, but this method has many uncertain when anatomical structure is very complicated. It is very important to know the exact position of the proton beam distal fall-off, or beam range, in the patient's body for both the safety of the patient and the effectiveness of the treatment itself. In 2003, Stichelbaut and Jongen reported the possibility of using the right-angled prompt gamma rays, which are emitted at 90 .deg. from the incident proton beam direction, to determine the position of the proton beam distal fall-off. They studied the interactions of the protons and other secondary particles in a water phantom and concluded that there is a correlation between the position of the distal fall-off and the distribution of the right-angled prompt gamma rays. We have recently designed a prompt gamma scanning system to measure the proton range in situ by using Monte Carlo technique employing MCNPX, FLUKA, and Sabrina TM . The prompt gamma scanning system was designed to measure only the right-angled prompt gamma rays passing through a narrow collimation hole in order to correlate the position with the dose distribution. The collimation part of the scanning system, which has been constructed to measure the gamma rays at 70 MeV of proton energy, is made of a set of paraffin, boron carbide, and lead layers to shield the high-energy neutrons and secondary photons. After the different proton energies and SOBP beam widths are irradiated at the water phantom. we detected prompt gamma at 5 cm

A simple method for conversion of airborne gamma-ray spectra to ground level doses

DEFF Research Database (Denmark)

Korsbech, Uffe C C; Bargholz, Kim

1996-01-01

A new and simple method for conversion of airborne NaI(Tl) gamma-ray spectra to dose rates at ground level has been developed. By weighting the channel count rates with the channel numbers a spectrum dose index (SDI) is calculated for each spectrum. Ground level dose rates then are determined...... by multiplying the SDI by an altitude dependent conversion factor. The conversion factors are determined from spectra based on Monte Carlo calculations. The results are compared with measurements in a laboratory calibration set-up. IT-NT-27. June 1996. 27 p....

Low rate doses effects of gamma radiation on glycoproteins of transmembrane junctions in fibroblasts

International Nuclear Information System (INIS)

Bringas, J.E.; Caceres, J.L.

1996-01-01

Glycoproteins of trans-membrane junctions are molecules that help to bind cells with the extracellular matrix. Integrins are the most important trans-membrane molecules among others. The damage of gamma radiation on those proteins could be an important early event that causes membrane abnormalities which may lead to cell malfunction and cancer induced by radiation due to cell dissociation. Randomized blocks with 3 repetitions of mouse embryo fibroblast cultures, were irradiated with Cobalt-60 gamma rays, during 20 days. Biological damage to glycoproteins and integrins was evaluated by cellular growth and fibroblast proliferative capacity. Integrins damage was studied by isolation by column immunoaffinity chromatography migrated on SDS-Page under reducing and non reducing conditions, and inhibition of integrins extracellular matrix adhesion by monoclonal antibodies effect. The dose/rate (0.05 Gy/day-0.2 Gy/day) of gamma given to cells did not show damage evidence on glycoproteins and integrins. If damage happened, it was repaired by cells very soon, was delayed by continuous cellular division or by glycoproteins characteristic of being multiple extracellular ligatures. Bio effects became more evident with an irradiation time greater than 20 days or a high dose/rate. (authors). 6 refs

Inhibition of alloxan diabetes by low dose {gamma}-irradiation before alloxan administration

Energy Technology Data Exchange (ETDEWEB)

Yamaoka, Kiyonori [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.; Takehara, Yoshiki; Yoshioka, Tamotsu; Utsumi, Kozo

1994-10-01

We evaluated the inhibitory effects of whole body {sup 60}Co-{gamma} irradiation at a single low dose on alloxan-induced hyperglycemia in rats. (1) In rats that received alloxan, SOD activity in pancreas significantly decreased, but the decrease was inhibited by irradiation at a dose of 0.5 Gy. (2) Similarly, plasma peroxide, pancreatic peroxide, and blood glucose increased. However, the increase in pancreatic peroxide was inhibited by irradiation at a dose of 0.5 or 1.0 Gy and the increase in blood glucose by irradiation at 0.5 Gy. (3) After alloxan administration, degranulation was observed in cells, but this was inhibited by irradiation at 0.5 Gy. These results suggest that alloxan diabetes was inhibited by the increase of SOD activity in pancreas after low dose irradiation at 0.5 Gy. (author).

Calculation of the gamma-dose rate from a continuously emitted plume

International Nuclear Information System (INIS)

Huebschmann, W.; Papadopoulos, D.

1975-06-01

A computer model is presented which calculates the long term gamma dose rate caused by the radioactive off-gas continuously emitted from a stack. The statistical distribution of the wind direction and velocity and of the stability categories is taken into account. The emitted activity, distributed in the atmosphere according to this statistics, is assumed to be concentrated at the mesh points of a three-dimensional grid. The grid spacing and the integration limits determine the accuracy as well as the computer time needed. When calculating the dose rate in a given wind direction, the contribution of the activity emitted into the neighbouring sectors is evaluated. This influence is demonstrated in the results, which are calculated with a error below 3% and compared to the dose rate distribution curves of the submersion model and the model developed by K.J. Vogt. (orig.) [de

Life shortening, tumor induction, and tissue dose for fission-neutron and gamma-ray irradiations

International Nuclear Information System (INIS)

Grahn, D.; Duggal, K.; Lombard, L.S.

1985-01-01

The primary focus of this program is to obtain information on the late effects of whole body exposure to low doses of a high linear-energy-transfer (LET) and a low-LET ionizing radiation in experimental animals to provide guidance for the prediction of radiation hazards to man. The information obtained takes the form of dose-response curves for life shortening and for the induction of numerous specific types of tumors. The animals are irradiated with fission neutrons from the Janus reactor and with 60 Co gamma rays, delivered as single, weekly, or duration-of-life exposures covering the range of doses and dose rates. 6 refs

Gamma-ray dose rate in air on the subway lines in Tokyo metropolitan area

International Nuclear Information System (INIS)

Ogawa, Masayuki; Hosoda, Masahiro; Ogashiwa, Susumu; Fukushi, Masahiro

2008-01-01

Measurements of gamma-ray dose rates in air were performed on 12 subway lines in Tokyo from the perspective of health physics, because the subways are commonly used for commuting in the Tokyo metropolitan area. The results showed that the maximum dose rate (36.5 nGy/h) was 1.6 times higher than that of the minimum one (23.3 nGy/h), and that the dose rate in the subway car was 33% lower than the outside. Also the results strongly suggested that the dose rates depend on the concentration of natural radionuclide around the subway lines and the platform structures rather than the depth. (author)

External gamma radiation dose studies in the proposed uranium mining areas of Andhra Pradesh, India

International Nuclear Information System (INIS)

Reddy, P.; Reddy, K.; Reddy, C.; Reddy, K.

2006-01-01

Natural radiation sources contribute the largest component to the total effective dose received by the human population. Among these sources, natural background gamma radiation shares a noteworthy amount. The present study aims at the establishment of baseline environmental gamma radiation data in the environs of proposed uranium mining areas of Andhra Pradesh, India. To this end, a systematic study has been undertaken using Thermoluminescence (T.L.) dosimeters and G.M. (Geiger - Muller) tube based survey meter. These levels are estimated both indoors and outdoors in the study area covering about 23 villages surrounding the proposed mining sites. The estimated external gamma radiation levels (air kerma) varied from 0.605 to 4.39 mGy.y -1 . The mean indoor to outdoor radiation level ratio is found to be 1.1 ± 0.1. The estimated mean equivalent doses due to external background radiation in the villages of the study area range from 1.03 to 2.83 mSv.y -1 with a mean of 2.34 ± 0.39 mSv.y -1 . (authors)

Modeling gamma radiation dose in dwellings due to building materials.

Science.gov (United States)

de Jong, Peter; van Dijk, Willem

2008-01-01

A model is presented that calculates the absorbed dose rate in air of gamma radiation emitted by building materials in a rectangular body construction. The basis for these calculations is formed by a fixed set of specific absorbed dose rates (the dose rate per Bq kg(-1) 238U, 232Th, and 40K), as determined for a standard geometry with the dimensions 4 x 5 x 2.8 m3. Using the computer codes Marmer and MicroShield, correction factors are assessed that quantify the influence of several room and material related parameters on the specific absorbed dose rates. The investigated parameters are the position in the construction; the thickness, density, and dimensions of the construction parts; the contribution from the outer leave; the presence of doors and windows; the attenuation by internal partition walls; the contribution from building materials present in adjacent rooms; and the effect of non-equilibrium due to 222Rn exhalation. To verify the precision, the proposed method is applied to three Dutch reference dwellings, i.e., a row house, a coupled house, and a gallery apartment. The averaged difference with MCNP calculations is found to be 4%.

Effects of low dose gamma- and UV-radiation on sea urchin eggs and spermatozoa

International Nuclear Information System (INIS)

Czihak, G.K.

1991-01-01

The paper outlines the results of a study of the effects of low dose gamma-and UV-irradiation on sea urchin eggs and spermatozoa with particular reference to the effects on the stages of the mitotic cycle and individual susceptibility. (UK)

Effect of low dose {gamma} radiation on the dormancy breaking and physiological activity of 'Dejima' seed potato

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Kim, D. H.; Baek, M. H.; Lee, Y. K. [KAERI, Taejon (Korea, Republic of); Lee, Y. B. [Chungnam National Univ., Taejon (Korea, Republic of)

2001-05-01

To observe the stimulating effects of low dose {gamma}-radiation on the dormancy breaking and physiological activity, potato (Solanum tuberosum L. cv. Dejima) were irradiated at the dose of 0.5 {approx} 30 Gy. Low dose {gamma}-radiation had promoting effects on the srouting rate the optimum dose of 1 Gy and 2 Gy and on the sprout length at the optimum dose of 2 Gy and 4 Gy. In case of number of sprouts, there were increased in all of the low dose irradiation groups and period storages, which showed very significant promoting effects at 4,8,16 Gy of 15 DAP. The field growth of 45 DAP were increased at all of the low dose irradiation group, which particularly were very significant promoting effect at 4 Gy irradiation group. Irradiation didn't have significant effects on the antioxidant enzyme activity of potato plantlet, but the peroxidase activity of 45 DAP plantlet increased at 4 Gy irradiation group.

Evaluation of mathematical methods for predicting optimum dose of gamma radiation in sugarcane (Saccharum sp.)

International Nuclear Information System (INIS)

Wu, K.K.; Siddiqui, S.H.; Heinz, D.J.; Ladd, S.L.

1978-01-01

Two mathematical methods - the reversed logarithmic method and the regression method - were used to compare the predicted and the observed optimum gamma radiation dose (OD 50 ) in vegetative propagules of sugarcane. The reversed logarithmic method, usually used in sexually propagated crops, showed the largest difference between the predicted and observed optimum dose. The regression method resulted in a better prediction of the observed values and is suggested as a better method for the prediction of optimum dose for vegetatively propagated crops. (author)

Feasibility of applying gamma irradiation as disinfestation technique on date fruits in respect to nutritional value that is affected by disinfesting gamma ray doses

International Nuclear Information System (INIS)

Ahmed, El-Sayed S.

1976-01-01

Infested and non-infested dry date fruits (Phonex dactylifera), Abrimi variety (9.2% moisture), with Ephestia cautella Walker were irradiated for 0, 15, 20 and 40 Krad gamma ray doses emitted from Co-60 source with 1.36 x 10-rad/h. as a dose rate. Irradiated fruits were stored at room temperature, at 20-25 0 C and 85-95% R.H., in packages to avoid reinfestation. A dose of 20 Krad is 100 percent effective in preventing the emergency of eggs, larva, and pupae in fruits as reflected by zero per cent emergency count for live adults. Also, this dose was found to be lethal for adult stage of the insect. On the other hand, 2 Krad dose does not produce significant changes in the nutritional qualities of fruits, as measured by chemical analytical means for carbohydrates, protein and amino acids, directly after irradiation as well as at 2, 4 and 6 months storage. The triangular tests show that irradiation treatments even with 4 Krad exerted no determinal effect upon the sensory qualities of stored irradiated date fruits. These results point out the feasibility of applying gamma irradiation, 20 Krad, as disinfestation technique against Ephestia cautella Walker in dry date fruits without exerting any effect on the nutritional value

Effects of gamma irradiation dose rate on microbiological and physical quality of mushrooms (Agaricus bisporus)

International Nuclear Information System (INIS)

Beaulieu, M.; Lacroix, M.; Charbonneau, R.; Laberge, I.; Gagnon, M.

1992-01-01

The effects of gamma irradiation (2 kGy) and dose rate of irradiation (4.5 and 32.0 kGy/h) on increasing the shelf-life and some quality properties of the mushrooms (Agaricus bisporus) were investigated during storage at 15 deg C and 90% R.H. The retardation of mushroom growth and ageing by reduction of gamma irradiation dose rate (4.5 kGy) was observed by measurements of the cap opening, the stipe increase, the cap diameter, the weight loss and the color of the caps. The color was measured in order to evaluate the lightness with the L value measurement and the color changes were measured in terms of lightness, hue and chroma. The control of fungal and bacterial diseases were also evaluated. The irradiation of mushrooms at both dose rates of irradiation was found to be effective in lowering microorganism counts initially and throughout storage and increased the shelf-life by four days. This study also showed that mushrooms exposed to a lower dose rate (4.5 kGy/h) of irradiation preserve the whiteness and reduce the stripe increase of mushrooms during storage

SU-F-T-370: A Fast Monte Carlo Dose Engine for Gamma Knife

Energy Technology Data Exchange (ETDEWEB)

Song, T; Zhou, L [Southern Medical University, Guangzhou, Guangdong (China); Li, Y [Beihang University, Beijing, Beijing (China)

2016-06-15

Purpose: To develop a fast Monte Carlo dose calculation algorithm for Gamma Knife. Methods: To make the simulation more efficient, we implemented the track repeating technique on GPU. We first use EGSnrc to pre-calculate the photon and secondary electron tracks in water from two mono-energy photons of 60Co. The total photon mean free paths for different materials and energies are obtained from NIST. During simulation, each entire photon track was first loaded to shared memory for each block, the incident original photon was then splitted to Nthread sub-photons, each thread transport one sub-photon, the Russian roulette technique was applied for scattered and bremsstrahlung photons. The resultant electrons from photon interactions are simulated by repeating the recorded electron tracks. The electron step length is stretched/shrunk proportionally based on the local density and stopping power ratios of the local material. Energy deposition in a voxel is proportional to the fraction of the equivalent step length in that voxel. To evaluate its accuracy, dose deposition in a 300mm*300mm*300mm water phantom is calculated, and compared to EGSnrc results. Results: Both PDD and OAR showed great agreements (within 0.5%) between our dose engine result and the EGSnrc result. It only takes less than 1 min for every simulation, being reduced up to ∼40 times compared to EGSnrc simulations. Conclusion: We have successfully developed a fast Monte Carlo dose engine for Gamma Knife.

On-site gamma dose rates at the Andreeva Bay shore technical base, northwest Russia.

Science.gov (United States)

Reistad, O; Dowdall, M; Standring, W J F; Selnaes, Ø G; Hustveit, S; Steinhusen, F; Sørlie, A

2008-07-01

The spent nuclear fuel (SNF) and radioactive waste (RAW) storage facility at Andreeva Bay shore technical base (STB) is one of the largest and most hazardous nuclear legacy sites in northwest Russia. Originally commissioned in the 1960s the facility now stores large amounts of SNF and RAW associated with the Russian Northern Fleet of nuclear powered submarines. The objective of the present study was to map ambient gamma dose rates throughout the facility, in particular at a number of specific sites where SNF and RAW are stored. The data presented here are taken from a Norwegian-Russian collaboration enabling the first publication in the scientific literature of the complete survey of on-site dose rates. Results indicate that elevated gamma dose rates are found primarily at discrete sites within the facility; maximum dose rates of up to 1000 microSv/h close to the ground (0.1m) and up to 3000 microSv/h at 1m above ground were recorded, higher doses at the 1m height being indicative primarily of the presence of contaminated equipment as opposed to ground contamination. Highest dose rates were measured at sites located in the immediate vicinity of buildings used for storing SNF and sites associated with storage of solid and liquid radioactive wastes. Elevated dose rates were also observed near the former channel of a small brook that became heavily contaminated as a result of radioactive leaks from the SNF storage at Building 5 starting in 1982. Isolated patches of elevated dose rates were also observed throughout the STB. A second paper detailing the radioactive soil contamination at the site is published in this issue of Journal of Environmental Radioactivity.

EPR response of sucrose and microcrystalline cellulose to measure high doses of gamma radiation

International Nuclear Information System (INIS)

Torijano, E.; Cruz, L.; Gutierrez, G.; Azorin, J.; Aguirre, F.; Cruz Z, E.

2015-10-01

Solid dosimeters of sucrose and microcrystalline cellulose (Avicel Ph-102) were prepared, following the same process, in order to compare their EPR response against that of the l-alanine dosimeters considered as reference. All lots of dosimeters were irradiated with gamma radiation in Gamma beam irradiator with 8 kGy/h of the Nuclear Sciences Institute of UNAM. Doses ranged from 1 to 10 kGy respectively. We found that both the response of sucrose as microcrystalline cellulose were linear; however, the response intensity was, on average, twenty times more for sucrose. Comparing this against the EPR response of l-alanine in the range of doses, it was found that the response to sucrose is a third part; and microcrystalline cellulose is a sixtieth, approximately. The results agree with those found in the literature for sucrose, leaving open the possibility of investigating other dosage ranges for cellulose. (Author)

Transferases activity in blood plasma of chickens hatched from eggs irradiated during incubation by low dose gamma rays

International Nuclear Information System (INIS)

Kraljevic, P.; Vilic, M.; Miljanic, S.; Simpraga, M.

2005-01-01

In our earlier studies chickens hatched from eggs irradiated with 0.15 Gy gamma rays before incubation showed a significantly higher growth than controls during the fattening period (1-42 days). The activity of aspartate-aminotransferase (AST), alanine-aminotransferase (ALT) and plasma glucose in the same chickens were also significantly higher. These results suggested that low-dose gamma-radiation stimulated certain metabolic processes in chickens hatched from eggs irradiated before incubation. The goal of this study was to determine the effects of low-dose ionising radiation on AST and ALT activity in the blood plasma of chickens hatched from eggs irradiated during incubation. The eggs of heavy breeding chickens (Avian, line 34) were exposed to 0.15 Gy of gamma-radiation (6 0C o) on the seventh day of incubation, i.e. at the time when the organogenesis in chickens is completed. The control group of chickens hatched from non-irradiated eggs. All other conditions were the same for both groups. After hatching, blood samples were taken from the wing vein on days 1, 3, 5, 7, 10, 20, 32 and 42. The activity of both enzymes was determined spectrophotometrically using Boehringer Mannheim GmbH optimised kits. On day 10, AST and ALT activity were significantly higher in the blood plasma of chickens hatched from irradiated eggs, but it significantly dropped for both enzymes on day 20. Our results indicate that exposure of eggs to low-dose gamma-radiation on the seventh day of incubation affects AST and ALT activity in the blood plasma of chickens hatched from irradiated eggs. However, this effect is somewhat different from the effects of egg exposure to low-dose gamma radiation before incubation.(author)

Gonad, bone marrow and effective dose to the population of more than 90 towns and cities of Iran, arising from environmental gamma radiation

International Nuclear Information System (INIS)

Bahreyni Toossi, M.T.; Bayani, S.H.; Abdolrahimi, A.; Yarahmadi, M.; Aghamir, A.; Jomehzadeh, A.; Hagh Parast, M.; Tamjidi, A.

2008-01-01

Natural radiation environment and it's biological impacts on human life has not received appreciable attention in Iran. Before 1996 only a few sporadic studies had been carried out, but no systematic study of normal back ground had been conducted. Since 1996 assessment of environmental gamma radiation dose in residential areas of Iranian towns and cities was defined as a long term goal in our center. Till now measurements of annual dose rates have been accomplished for 10 counties. As a practical method and based on the results of a pilot study, in order to attribute the final results to the whole residential area of a town five stations were selected for every town. The location of individual station was studied closely to comply with recommended conditions in the literature. RDS-110 was employed to measure gamma dose rate for one hour. Practically huge numbers of dose rate figures were recorded, they were substantially summarized to estimate average dose rate. Average annual dose rates plus conversion coefficients were employed to estimate gonad, bone marrow, equivalent and effective dose. In the vast studied area average out-door gamma dose rate is varying from 35 nSvh -1 to 205 nSvh -1 . Minimum and maximum annual bone marrow and gonad dose equivalent attributed to environmental gamma are 0.24 mSvy -1 (for both tissues) and 1.44 and 1.46 mSvy -1 respectively. Effective dose of inhabitants arising from out-door gamma is varying by 6 folds from 0.21 to 1.26 mSvy -1 . The largest and smallest population weighted dose are equal to 0.35 and 1.00 mSvy -1 . Average gonad and bone marrow doses for north Khorasan, Boshehr and Hormozgan are less than the corresponding values for normal area. On the other hand inhabitants of the studied area receive a dose higher than the world average, except those who live in Hormozgan and Boshehr. (author)

Non-linear dose response of a few plant taxa to acute gamma radiation

International Nuclear Information System (INIS)

George, J.T.; Patel, B.B.; Pius, J.; Narula, B.; Shankhadarwar, S.; Rane, V.A.; Venu-Babu, P.; Eapen, S.; Singhal, R.K.

2014-01-01

Micronuclei induction serves as an essential biomarker of radiation stress in a living system, and the simplicity of its detection technique has made it a widely used indicator of radiation damage. The present study was conducted to reveal the cytological dose-response of a few plant taxa, viz., Allium cepa var. aggregatum Linn., Allium sativum Linn., Chlorophytum comosum (Thunb.) Jacques and Eichhornia crassipes (Mart.) Solms, to low LET gamma radiation with special emphasis on the pattern of micronuclei induced across low and high dose regimes. A tri-phasic non-linear dose-response pattern was observed in the four taxa studied, characterized by a low dose linear segment, a plateau and a high dose linear segment. Despite a similar response trend, the critical doses where the phase transitions occurred varied amongst the plant taxa, giving an indication to their relative radiosensitivities. E. crassipes and A. sativum, with their lower critical doses for slope modifications of phase transitions, were concluded as being more radiosensitive as compared to C. comosum and A. cepa, which had relatively higher critical doses. (author)

Determining lethal dose of gamma radiation on different stages of Tribolium Cosmonauts H b s t

International Nuclear Information System (INIS)

Zolfagharieh, H.R.; Majd, F.; Torshyzie, M.; Babaie, M.

1992-10-01

Pest infestation causes great losses to stored grain through out the world. This is specially true in developing countries where the technology is less advanced, and climatic conditions are extremely favourable for the development of pests. Irradiation is on approved method of direct control for stored-product insect in wheat and wheat flour in many countries, and in dictation are that it will soon be approved for all grain, grain products and other dry food commodities. Radiation doses required to kill or sterilized the most important storage pests in all stages are known. However irradiation is very effective in preventing insect development and in producing sterility. A detailed analysis of the radiosensitivity of stored-product insects shows the different groups of pests have very different sensitivities and quarantine doses can be tailored to kill or sterilize the species of quarantine concern. The effect of irradiation on insects are many, and varied, depending primarily on the species, stage, age and physical factors. The aim is to survey the effect of gamma radiation on stored pest, which can categorized under following classes: 1-The effect of gamma radiation on different stages grow of tribolium castaneum (H B S T); 2-Determination of lethal doses.; 3-The study of gamma radiation on products. In summary these information indicated that fairly low dosages of gamma radiation could be used on commodities such as bulk grain in which some infestation by insect stages of irradiation would be required on products such package foods where hundred percent mortality must be obtain. (author)

The effect of low doses of gamma rays on hatchability of broiler parent stocks

International Nuclear Information System (INIS)

Zakaria, Abdul-Hamid

1990-01-01

It is a summary of the report written about the three experiments which have been carried out to study the stimulatory effect of different doses of gamma irradiation on the hatchability of broiler parent stocks at 45 weeks of age. It has been shown that doses at 0.1 and 0.15 GY had a stimulatory effect on hatchability of highly-fertile broiler parent stock. Doses at 1.20, 1.60 and 2.10 GY had an inhibitory effect on hatchability of low-fertile broiler parent stock. No significant difference has been detected on the chicks weights hatched from eggs exposed to doses ranged from 0.05 to 1.20 GY of highly-fertile broiler parent stock. 4 tabs

Electrical resistance behavior with gamma radiation dose in bulk carbon nanostrutured samples

International Nuclear Information System (INIS)

Lage, J.; Leyva, A.; Pinnera, I.; Desdin, L. F.; Abreu, Y.; Cruz, C. M.; Leyva, D.; Toledo, C.

2013-01-01

The aim of this paper is to study the effects of 60 Co gamma radiation on the electrical resistance and V-I characteristic of bulk carbon nano structured samples obtained by electric arc discharge in water method. Images of pristine samples obtained with scanning electron, and the results in graphical form of the electrical characterization of irradiated samples are presented in the text. It was observed that the electrical resistance vs. dose behavior shows an initial increment reaching the maximum at approximately 135 kGy, followed by a drop of the resistance values. These behaviors are associated with the progressive generation of radiation induced defects in the sample, whose number increases to reach saturation at 135 kGy. From this dose, defects could lead to cross-links between different nano structures present in the sample conducting to a gradually drop in electrical resistance. The measured V-I curves show that, increasing exposure to the 60 Co gamma radiation, the electrical properties of the studied samples transit from a semiconductor towards a predominantly metallic behavior. These results were compared with those obtained for a sample of graphite powder irradiated under the same conditions. (Author)

Dynamic gamma knife radiosurgery

International Nuclear Information System (INIS)

Luan Shuang; Swanson, Nathan; Chen Zhe; Ma Lijun

2009-01-01

Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C(TM) and Perfexion(TM) units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and

Dose rate effect on material aging due to radiation. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Okamoto, Shin-ichi (Radiation Center of Osaka Prefecture, Sakai (Japan)); Hayakawa, Chikara; Takeya, Chikashi

1982-12-01

Although many reports have been presented on the radiation aging of the organic materials for electric cables, those have been based on the experiments carried out at high dose rate near 1 x 10/sup 6/ rad/h, assuming that aging effect depends on only radiation dose. Therefore, to investigate the aging behaviour in low dose rate range is an important subject to predict their practical life time. In this report, the results of having investigated the aging behaviour of six types of materials are described, (polyethylene for general insulation purpose, chemically cross-linked polyethylene, fire-retardant chemically cross-linked polyethylene, fire-retardant ethylene-propylene rubber, fire-retardant chloro-sulfonated polyethylene for sheaths, and fire-retardant, low hydrochloric acid, special heat-resistant vinyl for insulation purpose or chloroclean). They were irradiated with /sup 60/Co ..gamma..-ray at the dose from 5 x 10/sup 3/ to 1 x 10/sup 6/ rad/h, and their deterioration was tested for the items of elongation, tensile strength, resistivity, dielectric tangent and gel fraction. The aging mechanism and dose rate effect were also considered. The dose rate effect appeared or did not appear depending on the types of materials and also their properties. The materials that showed the dose rate effect included the typical ones whose characteristics degraded with the decreasing dose rate, and the peculiar ones whose deterioration of characteristics did not appear constantly. Aging mechanism may vary in the case of high dose rate and low dose rate. Also, if the life time at respective dose rate in relatively higher dose rate region is clarified, the life time in low dose rate region may possibly be predicted.

A MATHEMATICAL APPROACH TO ECONOMY OF EXPERIMENT IN DETERMINATIONS OF THE DIFFERENTIAL DOSE ALBEDO OF GAMMA RAYS

Energy Technology Data Exchange (ETDEWEB)

Shoemaker, N. F.; Huddleston, C. M.

1962-12-10

Treatments of the differential dose albedo of gamma rays on concrete have supposed that the albedo value is a function of: the energy of the incident gamma radiation, the polar angle of incidence, the polar angle of reflection (or scatter), and the azimuthal angle of reflection. It is demonstrated that, if certain reasonable assumptions are made regarding the mechanism of reflection, it is not necessary to investigate variations in albedo with azimuthal angle of refiection. Once differential dose albedo has been determined for a complete set of incident and reflected polar angles with zero azimuth, albedo at any azimuth can be derived by a suitable transformation. (auth)

Characterization by Monte Carlo of the dose after a glass shield lead for gamma ray; Caracterizacion por Monte Carlo de la dosis tras un blindaje de vidrio de plomo para rayos gamma

Energy Technology Data Exchange (ETDEWEB)

Esteve Sanchez, S.; Gil Conde, M.; Contreras Gonzalez, J. L.; Rosado, J.; Pazyi, V.

2013-07-01

When a gamma-ray beam crosses the border between two media characterized by atomic number very different is they produce effects on the distribution of doses near the border difficult to predict with simple models. The case of rays gamma affecting a lead glass is particularly interesting for its application to shielding of common use. interested in studying the importance of the residual dose after the shield. (Author)

Impact peculiarities of long-term gamma-irradiation with low-dose rate on the development of laboratory rats and their sperm production

International Nuclear Information System (INIS)

Klepko, A.V.; Motrina, O.A.; Vatlyitsova, O.S.; And Others

2015-01-01

The experiments were performed on laboratory white rats of 2.5 months in age. Animals were irradiated in gamma-field of 'Ethalon' device in a dose range 0.1-1.0 Gy. Testicles, epididymices, ventral prostate were retrieved from decapitated animal, each organ weight being determined for every exposure dose. Sperm quantities in testicles and epididymices were identified with aid of phase-contrast microscopy after tissue homogenization in saline containing Triton X-100 and NaN_3. Kinetic characteristics of spermatozoa were analyzed by video recording at 37 C. The longterm gamma-irradiation with low dose rate was shown to cause no effect on the dynamics of animal weight and weight of epididymices changes. However the testes weight was noticed to diminish at doses 0.1, 0.3, 0.6 and 1.0 Gy, the latter dose being stimulative for the ventral prostate growth and weight accumulation. Total sperm quantities in testicles and epididymices along with daily sperm production declined in gamma-irradiated rats compared to control. However curvilinear and straight line spermatozoid velocity as well as the frequency of tail oscillations tended to increase. Long-term gamma-irradiation of the rat whole body with low dose rate just insignificantly affects the development of testes and ventral prostate. Apart from this, radiation effects showed up in sperm production slight suppression, from the on hand, and sperm velocity along with tail oscillations intensification, from the other hand

Gonad, bone marrow and effective dose to the population of more than 90 towns and cities of Iran, arising from environmental gamma radiation

International Nuclear Information System (INIS)

Bahreyni Toossi, M. T.; Bayani, Sh.; Yarahmadi, M.; Aghamir, A.; Jomehzadeh, A.; Hagh Parast, M.; Tamjidi, A.

2009-01-01

Since 1996 the assessment of environmental gamma radiation dose in residential areas of Iranian towns and cities has been accomplished for 10 counties. As a practical method and based on the results of a pilot study, in order to attribute the final results to the whole residential area of a town five stations were selected for every town. The location of individual station was studied closely to comply with recommended conditions in the literature. Materials and Methods: RDS-110 was employed to measure gamma dose rate for one hour. Average annual dose rates plus conversion coefficients were employed to estimate gonad, bone marrow, equivalent and effective dose. Result: Minimum and maximum annual bone marrow and gonad dose equivalent attributed to environmental gamma are 0.24 mSvy -1 (for both tissues) and 1.44 and 1.46 mSvy -l , respectively. Conclusion: Average gonad and bone marrow doses for North Khorasan, Boshehr and Hormozgan provinces were less than the corresponding values for normal area.

Effect of low doses of gamma radiation of Co-60 (radio-hormesis) in tomato seeds

International Nuclear Information System (INIS)

Wiendl, Toni Andreas

2010-01-01

Tomato seeds of the Gladiador hybrid were exposed to gamma radiation of Co-60 with the following doses: 0; 2,5; 5; 7,5; 10; 12,5; 15 e 20 Gy. Analysis were performed on germination, seedlings height to cotyledon, seedling total height, seedling fresh and dry weight, plant height, stalk diameter at the root beginning, fresh and dry weight of the 5 th leaf, number of green fruits with diameter higher than 3 cm, number of green, half ripen and ripen fruits, total number of fruits, Brix and pH of fruits, average fruit weight and fruit total production. A variety of stimulation effects were observed on the different plant developing stages. The greatest stimulus for production was observed in the 10 Gy dose. The highest seedling average height and plant average height were observed for the 7,5 Gy dose. The biggest number of green fruits with diameter higher than 3 cm occurred for the 12,5 and 15 Gy treatments. Irradiation also stimulated a higher total number of fruits in all doses, having advantage the 10 Gy dose which produced 88% more fruits than control as well as 86% more weight production. The fruits pH acidified significantly in a dose of 12,5 Gy and higher. Production increased in all treatments comparing to control and the highest stimulus for production observed was for the 10, 12,5 and 15 Gy. The use of low gamma radiation doses of Co-60 applied as pre-sowing treatment in the seeds, efficiently stimulated the development of plants and the tomato production. (author)

Transport calculations of. gamma. -ray flux density and dose rate about implantable californium-252 sources

Energy Technology Data Exchange (ETDEWEB)

Shapiro, A; Lin, B I [Cincinnati Univ., Ohio (USA). Dept. of Chemical and Nuclear Engineering; Windham, J P; Kereiakes, J G

1976-07-01

..gamma.. flux density and dose rate distributions have been calculated about implantable californium-252 sources for an infinite tissue medium. Point source flux densities as a function of energy and position were obtained from a discrete-ordinates calculation, and the flux densities were multiplied by their corresponding kerma factors and added to obtain point source dose rates. The point dose rates were integrated over the line source to obtain line dose rates. Container attenuation was accounted for by evaluating the point dose rate as a function of platinum thickness. Both primary and secondary flux densities and dose rates are presented. The agreement with an independent Monte Carlo calculation was excellent. The data presented should be useful for the design of new source configurations.

Beta and Gamma Gradients

DEFF Research Database (Denmark)

Løvborg, Leif; Gaffney, C. F.; Clark, P. A.

1985-01-01

Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...... that the present practice of avoiding samples above a depth of 0.3 m may be over-cautious...

Stereotactic radiosurgery with the gamma knife. Possibilities of dose distribution optimizations

International Nuclear Information System (INIS)

Stuecklschweiger, G.

1995-01-01

On April 1992, the first stereotactic radiosurgical procedure using the gamma knife was performed at the University Medical School Graz, Department of Neurosurgery. Accurate dose optimization is the foundation of a convenient and responsible utilization of this modality. But there are limits, because the final collimation is only achieved by 1 of the 4 special helm collimators. The possibilities of dose optimization and its influence on the dose distributions were investigated and partly compared with results of film densitometry measurements. In detail, the technique, which uses the same isocenter, but different sized collimators was studied. The influence of these optimization techniques on the resulting dose distributions and the dose gradient at the edge of the treatment planning volume was analyzed. Also the visions for an effective dose optimization are discussed. With 2 shots of different diameters, located at the same target coordinates and different weighting of time any collimator size between the 4 mm and 18 mm can be achieved. Because of that, a combination of more than 2 collimators is not meaningful. With the combined shots the dose fall gradient was less than that of either of the single shots involved in the combination. With the available physical and technical possibilities only a limited, very time consuming optimization is practicable. The quality control of isodose distributions requires optimizations in hard-and software, that enable CT- or MRT-based 3-dimensional visualization and dose volume analysis. (orig./MG) [de

Gamma-Dose rate above uranium mineralization areas in western sudan

International Nuclear Information System (INIS)

Sam, A.K; Sirelkhatim, D.A; Hassona, R.K.

2003-01-01

Absorbed dose rate received from natural external irradiation in uranium mineralisation areas at Uro, Kurun and Jebel Mun was evaluated from the measured activity concentrations of 238 U, 232 Th and 40 K in rock samples.The analyses were performed using alpha-spectrometry and high-resolution gamma-ray spectrometry. A great spatial variability was observed in activity concentration of the primordial radionuclides indicating complexity in geological features. Converses to Jebel Mun, Uro and Kurun deposits exhibit very high U:Th mass ratio. The resulting absorbed dose rate in air as estimated using DRCF's fall within the range of 70-522 (Mun), 569-349 (Uro) and 84-320 n Gy/h (Kurun). At maximum, they correspond to annual effective dose of 0.64, 7.78 and 0.39 mSv, respectively. Uranium is the principal producer of the surface radioactivity at Uro and Kurun as it contributes 99.6% and 95% of the total absorbed dose whereas, in Jebel Mun the cause of radioactive anomaly is due to 40 K and 232 Th. In Uro and Kurun deposits, daughter/parent activity ratios along uranium series, Viz. 234 U: 238 U, 230 Th:U, 210 Po:U, are not differ from the equilibrium value of unity.(Author)

Role and Successes of Trilateral Liaison Frameworks (IAEA-SSACs/RSACs- Nuclear Fuel Cycle Facility Operators) in Monitoring the Quality of the Operator's Measurement and Accounting Systems

International Nuclear Information System (INIS)

Norman, C.; Zhao, K.; Christophe, P.; Binner, R.; Iso, S.

2015-01-01

Two of the three generic objectives of safeguards under a comprehensive safeguards agreement (CSA) are to detect any undeclared production or processing of nuclear material in declared facilities and locations outside facilities (LOFs) and to detect any diversion of declared nuclear material at facilities and LOFs. The effectiveness and efficiency of the IAEA in reaching these objectives strongly relies on the quality of the State or regional system of accounting for and control of nuclear material (SSAC/RSAC) which in turn depends on the nuclear fuel cycle facility operators' capabilities to establish accurate and precise estimates of the inventories and flow of nuclear material. To monitor the performance of the State's nuclear fuel cycle facilities' accounting and measurement systems in a collaborative way, the IAEA initiated yearly trilateral liaison meetings with relevant State or regional authorities and bulk handling facilities' operators to review material balance evaluation results for the elapsed material balance period and their trends over the facility lifetime. During these meetings, trends of concern are examined and the IAEA proposes remedial actions, drawing on its expertise and experience of observations in similar facilities. Pilot trilateral meetings held in Japan over the past years demonstrate the benefits of this collaborative framework. Biases in material balance variables are identified, their causes determined and a set of recommendations is drawn to implement remedial actions before they become a safeguards concern. In the margins of these meetings, workshops are also organised to foster exchanges in the fields of measurement and analytical methods as well as statistical methodologies used to determine their uncertainties and assess the sensitivity of material balances to these uncertainties. In the context of its strategy to enhance cooperation with States, reinforce mutual trust and pursue further efficiencies though

Gamma-ray dose analysis for ITER JA WCCB-TBM

Energy Technology Data Exchange (ETDEWEB)

Sato, Satoshi, E-mail: sato.satoshi92@jaea.go.jp [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan); Tanigawa, Hisashi; Hirose, Takanori; Enoeda, Mikio [Japan Atomic Energy Agency, Naka-shi, Ibaraki (Japan); Ochiai, Kentaro; Konno, Chikara [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan)

2014-10-15

To evaluate the nuclear properties of the International Thermonuclear Experimental Reactor (ITER) JA Water-Cooled Ceramic Breeder Test Blanket Module (WCCB-TBM) and to ensure its design conforms to nuclear licensing regulations, nuclear analyses have been performed for the WCCB-TBM's components, including its frame, shield, flange, port extension, pipe forest, bio-shield and Ancillary Equipment Unit (AEU). Utilising Monte Carlo code MCNP5.14, activation code ACT-4 and the Fusion Evaluated Nuclear Data Library FENDL-2.1, this paper focusses on the shutdown dose rate calculation for the WCCB-TBM. Monte Carlo N-Particle Transport Code (MCNP) geometry input data for the TBM are created from computer-aided design (CAD) data using the CAD/MCNP automatic conversion code GEOMIT, and other geometry input data are created manually. The ‘Direct 1-Step Monte Carlo’ method is adopted for the decay gamma-ray dose rate calculation. Behind the bio-shield, the effective dose rates 1 day after shutdown are about 0.2 μSv h{sup −1}, which are much lower than 10 μSv h{sup −1}, the upper limit for human access. Behind the flange, the effective dose rates 10{sup 6} s after shutdown are 50–80 μSv h{sup −1}, which are lower than 100 μSv h{sup −1}, the upper limit for human hands-on access for workers performing maintenance.

Intensity of the absorbing dose of the gamma rays in the air of Krusevac during and after nuclear accident in Chernobil

International Nuclear Information System (INIS)

Fortuna, D.

1997-01-01

In this paper are compared overage daily values of the intensity of the absorbing doses of the gamma rays in the air of Krusevac, during and after nuclear accident in Cernobil. Average daily values of intensity of the absorbing doses of gamma rays in the air of Krusevac, immediately after nuclear accident in Cernobil were, three to seven time higher than of the average daily values of the natural rays. (author)

Natural gamma-ray spectrometry as a tool for radiation dose and radon hazard modelling

International Nuclear Information System (INIS)

Verdoya, M.; Chiozzi, P.; De Felice, P.; Pasquale, V.; Bochiolo, M.; Genovesi, I.

2009-01-01

We reviewed the calibration procedures of gamma-ray spectrometry with particular emphasis to factors that affect accuracy, detection limits and background radiation in field measurements for dosimetric and radon potential mapping. Gamma-ray spectra were acquired in western Liguria (Italy). The energy windows investigated are centred on the photopeaks of 214 Bi (1.76 MeV), 208 Tl (2.62 MeV) and 40 K (1.46 MeV). The inferred absorbed dose rate and the radon flux are estimated to be lower than 60 nGy h -1 and 22 Bq m -2 h -1 , respectively.

Supplementary comparison CCRI(I)-S2 of standards for absorbed dose to water in 60Co gamma radiation at radiation processing dose levels

DEFF Research Database (Denmark)

Burns, D. T.; Allisy-Roberts, P. J.; Desrosiers, M. F.

2011-01-01

Eight national standards for absorbed dose to water in 60Co gamma radiation at the dose levels used in radiation processing have been compared over the range from 1 kGy to 30 kGy using the alanine dosimeters of the NIST and the NPL as the transfer dosimeters. The comparison was organized...... by the Bureau International des Poids et Mesures, who also participated at the lowest dose level using their radiotherapy-level standard for the same quantity. The national standards are in general agreement within the standard uncertainties, which are in the range from 1 to 2 parts in 102. Evidence of a dose...

Quantitative and qualitative changes induced by low-dose gamma irradiation in essential oil of Cymbopogon martinii var. motia

International Nuclear Information System (INIS)

Gupta, R.S.; Verma, Sheela; Trivedi, K.C.; Gangrade, S.K.

1981-01-01

Seeds of palmarosa grass were exposed to low doses of gamma-rays. The effects on quantitative and qualitative characters were studied in M 1 generation for two years. Highest response in quantitative and qualitative characters was observed in 10 Kr and 15 Kr doses. (author)

Neutron flux and gamma dose measurement in the BNCT irradiation facility at the TRIGA reactor of the University of Pavia

Science.gov (United States)

Bortolussi, S.; Protti, N.; Ferrari, M.; Postuma, I.; Fatemi, S.; Prata, M.; Ballarini, F.; Carante, M. P.; Farias, R.; González, S. J.; Marrale, M.; Gallo, S.; Bartolotta, A.; Iacoviello, G.; Nigg, D.; Altieri, S.

2018-01-01

University of Pavia is equipped with a TRIGA Mark II research nuclear reactor, operating at a maximum steady state power of 250 kW. It has been used for many years to support Boron Neutron Capture Therapy (BNCT) research. An irradiation facility was constructed inside the thermal column of the reactor to produce a sufficient thermal neutron flux with low epithermal and fast neutron components, and low gamma dose. In this irradiation position, the liver of two patients affected by hepatic metastases from colon carcinoma were irradiated after borated drug administration. The facility is currently used for cell cultures and small animal irradiation. Measurements campaigns have been carried out, aimed at characterizing the neutron spectrum and the gamma dose component. The neutron spectrum has been measured by means of multifoil neutron activation spectrometry and a least squares unfolding algorithm; gamma dose was measured using alanine dosimeters. Results show that in a reference position the thermal neutron flux is (1.20 ± 0.03) ×1010 cm-2 s-1 when the reactor is working at the maximum power of 250 kW, with the epithermal and fast components, respectively, 2 and 3 orders of magnitude lower than the thermal component. The ratio of the gamma dose with respect to the thermal neutron fluence is 1.2 ×10-13 Gy/(n/cm2).

SU-E-T-594: Out-Of-Field Neutron and Gamma Dose Estimated Using TLD-600/700 Pairs in the Wobbling Proton Therapy System

International Nuclear Information System (INIS)

Chen, Y; Lin, Y; Chen, H; Tsai, H

2015-01-01

Purpose: Secondary fast neutrons and gamma rays are mainly produced due to the interaction of the primary proton beam with the beam delivery nozzle. These secondary radiation dose to patients and radiation workers are unwanted. The purpose of this study is to estimate the neutron and gamma dose equivalent out of the treatment volume during the wobbling proton therapy system. Methods: Two types of thermoluminescent (TL) dosimeters, TLD-600 ( 6 LiF: Mg, Ti) and TLD-700 ( 7 LiF: Mg, Ti) were used in this study. They were calibrated in the standard neutron and gamma sources at National Standards Laboratory. Annealing procedure is 400°C for 1 hour, 100°C for 2 hours and spontaneously cooling down to the room temperature in a programmable oven. Two-peak method (a kind of glow curve analysis technique) was used to evaluate the TL response corresponding to the neutron and gamma dose. The TLD pairs were placed outside the treatment field at the neutron-gamma mixed field with 190-MeV proton beam produced by the wobbling system through the polyethylene plate phantom. The results of TLD measurement were compared to the Monte Carlo simulation. Results: The initial experiment results of calculated dose equivalents are 0.63, 0.38, 0.21 and 0.13 mSv per Gy outside the field at the distance of 50, 100, 150 and 200 cm. Conclusion: The TLD-600 and TLD-700 pairs are convenient to estimate neutron and gamma dosimetry during proton therapy. However, an accurate and suitable glow curve analysis technique is necessary. During the wobbling system proton therapy, our results showed that the neutron and gamma doses outside the treatment field are noticeable. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1C0682)

SU-E-T-594: Out-Of-Field Neutron and Gamma Dose Estimated Using TLD-600/700 Pairs in the Wobbling Proton Therapy System

Energy Technology Data Exchange (ETDEWEB)

Chen, Y [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Lin, Y [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Medical Physics Research Center, Institute for Radiological Research, Chang Gung University / Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan (China); Chen, H [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan (China); Tsai, H [College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan (China); Medical Physics Research Center, Institute for Radiological Research, Chang Gung University / Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan (China); Healthy Aging Research Center, Chang Gung University, Linkou, Taoyuan, Taiwan (China)

2015-06-15

Purpose: Secondary fast neutrons and gamma rays are mainly produced due to the interaction of the primary proton beam with the beam delivery nozzle. These secondary radiation dose to patients and radiation workers are unwanted. The purpose of this study is to estimate the neutron and gamma dose equivalent out of the treatment volume during the wobbling proton therapy system. Methods: Two types of thermoluminescent (TL) dosimeters, TLD-600 ({sup 6}LiF: Mg, Ti) and TLD-700 ({sup 7}LiF: Mg, Ti) were used in this study. They were calibrated in the standard neutron and gamma sources at National Standards Laboratory. Annealing procedure is 400°C for 1 hour, 100°C for 2 hours and spontaneously cooling down to the room temperature in a programmable oven. Two-peak method (a kind of glow curve analysis technique) was used to evaluate the TL response corresponding to the neutron and gamma dose. The TLD pairs were placed outside the treatment field at the neutron-gamma mixed field with 190-MeV proton beam produced by the wobbling system through the polyethylene plate phantom. The results of TLD measurement were compared to the Monte Carlo simulation. Results: The initial experiment results of calculated dose equivalents are 0.63, 0.38, 0.21 and 0.13 mSv per Gy outside the field at the distance of 50, 100, 150 and 200 cm. Conclusion: The TLD-600 and TLD-700 pairs are convenient to estimate neutron and gamma dosimetry during proton therapy. However, an accurate and suitable glow curve analysis technique is necessary. During the wobbling system proton therapy, our results showed that the neutron and gamma doses outside the treatment field are noticeable. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1C0682)

Gamma Radiation Dose from Radionuclides in Soil Samples of Udagamandalam (Ooty) in India

International Nuclear Information System (INIS)

Selvasekarapandian, S.; Muguntha Manikandan, N.; Sivakumar, R.; Balasubramanian, S.; Venkatesan, T.; Meenakshisundram, V.; Ragunath, V.M.; Gajendran, V.

1999-01-01

The systematic study of background radiation and the distribution of radionuclides in the environment of Udagamandalam in Nilgiri District of Tamil Nadu has been made. Gamma spectrometric analysis of the soil samples of this area has been carried out. The measured gamma dose in air is in the range 31.6 nGy.h -1 - 221.1 nGy.h -1 with a mean value 121.8 nGy.h -1 . The average activities of the 232 Th series, 238 U series and 40 K in soil samples are 114.6 ± 52.5 Bq.kg -1 , 43.2 ± 23.2 Bq.kg -1 and 274.6 ± 86.7 Bq.kg -1 respectively. (author)

Inverse gamma ray dose rate effect in californium-252 RBE experiment with human T-1 cells irradiated in vitro

International Nuclear Information System (INIS)

Todd, P.; Feola, J.M.

1986-01-01

Metabolically deoxygenated suspensions of human T-1 cells were used to determine the RBE in hypoxia of low dose rate (LDR) Cf-252 radiation compared to LDR gamma radiation. Based upon the initial portion of the survival curves the RBE was 5.0 ± 1.0 for all components of the Cf-252 radiation and 7.1 ± 1.7 for the neutrons alone. An inverse dose rate effect was observed for LDR gamma radiation in which greater cell sensitivity was observed at lower dose rates and longer irradiation periods. It was demonstrated that there was little or no sublethal damage repair or cell progression during LDR at 21 deg C, and the observed decrease in cell survival probability with increasing irradiation time at a given dose was attributable to reoxygenation of the cell suspensions during the course of LDR exposures. (Auth.)

Beta and gamma dose calculations for PWR and BWR containments

International Nuclear Information System (INIS)

King, D.B.

1989-07-01

Analyses of gamma and beta dose in selected regions in PWR and BWR containment buildings have been performed for a range of fission product releases from selected severe accidents. The objective of this study was to determine the radiation dose that safety-related equipment could experience during the selected severe accident sequences. The resulting dose calculations demonstrate the extent to which design basis accident qualified equipment could also be qualified for the severe accident environments. Surry was chosen as the representative PWR plant while Peach Bottom was selected to represent BWRs. Battelle Columbus Laboratory performed the source term release analyses. The AB epsilon scenario (an intermediate to large LOCA with failure to recover onsite or offsite electrical power) was selected as the base case Surry accident, and the AE scenario (a large break LOCA with one initiating event and a combination of failures in two emergency cooling systems) was selected as the base case Peach Bottom accident. Radionuclide release was bounded for both scenarios by including spray operation and arrested sequences as variations of the base scenarios. Sandia National Laboratories used the source terms to calculate dose to selected containment regions. Scenarios with sprays operational resulted in a total dose comparable to that (2.20 x 10 8 rads) used in current equipment qualification testing. The base case scenarios resulted in some calculated doses roughly an order of magnitude above the current 2.20 x 10 8 rad equipment qualification test region. 8 refs., 23 figs., 12 tabs

Dynamic gamma knife radiosurgery

Energy Technology Data Exchange (ETDEWEB)

Luan Shuang; Swanson, Nathan; Chen Zhe [Department of Computer Science, University of New Mexico, Albuquerque, NM 87131 (United States); Ma Lijun [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94143 (United States)], E-mail: sluan@cs.unm.edu, E-mail: nate@cs.unm.edu, E-mail: zchen@cs.unm.edu, E-mail: lijunma@radonc.ucsf.edu

2009-03-21

Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C(TM) and Perfexion(TM) units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can

Estimation of outdoor and indoor effective dose and excess lifetime cancer risk from Gamma dose rates in Gonabad, Iran

Energy Technology Data Exchange (ETDEWEB)

Jafaria, R.; Zarghania, H.; Mohammadia, A., E-mail: rvzreza@gmail.com [Paramedical faculty, Birjand University of Medical Sciences, Birjand (Iran, Islamic Republic of)

2017-07-01

Background gamma irradiation in the indoor and outdoor environments is a major concern in the world. The study area was Gonabad city. Three stations and buildings for background radiation measurement of outdoor and indoor were randomly selected and the Geiger-Muller detector (X5C plus) was used. All dose rates on display of survey meter were recorded and mean of all data in each station and buildings was computed and taken as measured dose rate of that particular station. The average dose rates of background radiation were 84.2 nSv/h for outdoor and 108.6 nSv/h for indoor, maximum and minimum dose rates were 88.9 nSv/h and 77.7 nSv/h for outdoor measurements and 125.4 nSv/h and 94.1 nSv/h for indoor measurements, respectively. Results show that the annual effective dose is 0.64 mSv, which compare to global level of the annual effective dose 0.48 mSv is high. Estimated excess lifetime cancer risk was 2.24×10{sup -3} , indicated that it is large compared to the world average value of 0.25×10{sup -3}. (author)

Experimental verification of methods for gamma dose rate calculations in the vicinity of containers with the RA reactor spent fuel elements

International Nuclear Information System (INIS)

Milosevic, M.; Cupac, S.; Pesic, M.

2005-01-01

The methodology for equivalent gamma dose rate determination on the outer surface of existing containers with the spent fuel elements of the RA reactor is briefly summarised, and experimental verification of this methodology in the field of gamma rays near the aluminium channel with spent fuel elements lifted from the stainless steel containers no. 275 in the RA reactor hall is presented. The proposed methodology is founded on: the existing fuel burnup data base; methods and models for the photon source determination in the RA reactor spent fuel elements developed in the Vinca Institute, and validated Monte Carlo codes for the equivalent gamma dose rate calculations. (author) [sr

Gynogenesis with high doses of gamma radiation in tomatoes -Lycopersicum esculentum Mill. (L.)

International Nuclear Information System (INIS)

Dryanovska, O.A.

1983-01-01

The behaviour of male chromatin at the germination of gamma irradiated pollen from the stigma to the embrio sac in tomatoes was investigated in connection with the induced gynogenesis and the transfer of genetic information from one species to another. Two male-sterile longistil varieties of Deva and Hera were used as mothers, while mixed pollen from cultivated varieties and Lycopersicum peruvianum (L.) was irradiated at doses of 1, 5, 10 and 200 Kr with a dose rate of up to 1500 R/min. The experiment was carried out in 6 replications, with between 3 and 15 flowers for each variant and variety. The irradiated male chromatin of L. peruvianum remains in the pollen tube that has grown close to the embryo sac and stimulates the development of the embryo and endosperm. The absense of anthocyanin and the normal diploid chromosome count were the two markers for characterizing the plants obtained at high doses of gamma radiation as secondarily diploidized gynogenetic diplo-haploids during embryogenesis. It is assumed that the highly damaged male chromatin and the cytoplasm of the pollen tube retain their stimulating function under the influence of the high doses. A decisive role may be placed by certain fragments with genes from the male chromatin. The mitochondria which retain their respirative capacity and are promptly restored even after irradiation may have a stimmulating influence at the induced haploidy. The secondary diploidization normalizes the development of the organism of haploid origin and makes it possible to overcome the poor viability and the higher sterility. The genes responsible for the synthesis of anthocyanin in the irradiated male chromatin are restroyed by the high radiation doses, and this is the reason for the absence of anthocyanin in the diplo-haploid plants

Dose-response curve for blood exposed to gamma-neutron mixed field by conventional cytogenetic method

International Nuclear Information System (INIS)

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

2009-01-01

There is increasing concern about airline crew members (about one million worldwide) are exposed to measurable neutrons doses. Historically, cytogenetic biodosimetry assays have been based on quantifying asymmetrical chromosome alterations (dicentrics, centric rings and acentric fragments) in mytogen-stimulated T-lymphocytes in their first mitosis after radiation exposure. Increased levels of chromosome damage in peripheral blood lymphocytes are a sensitive indicator of radiation exposure and they are routinely exploited for assessing radiation absorbed dose after accidental or occupational exposure. Since radiological accidents are not common, not all nations feel that it is economically justified to maintain biodosimetry competence. However, dependable access to biological dosimetry capabilities is completely critical in event of an accident. In this paper the dose-response curve was measured for the induction of chromosomal alterations in peripheral blood lymphocytes after chronic exposure in vitro to neutron-gamma mixes field. Blood was obtained from one healthy donor and exposed to two neutron-gamma mixed field from sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The evaluated absorbed doses were 0.2 Gy; 1.0 Gy and 2.5 Gy. The dicentric chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphase figures were analyzed for the presence of dicentrics by two experienced scorers after painted by giemsa 5%. Our preliminary results showed a linear dependence between radiations absorbed dose and dicentric chromosomes frequencies. Dose-response curve described in this paper will contribute to the construction of calibration curve that will be used in our laboratory for biological dosimetry. (author)

Dose-response curve for blood exposed to gamma-neutron mixed field by conventional cytogenetic method

Energy Technology Data Exchange (ETDEWEB)

Brandao, Jose Odinilson de C.; Souza, Priscilla L.G.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F., E-mail: jodinilson@cnen.gov.b, E-mail: fflima@cnen.gov.b, E-mail: jasantos@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Calixto, Merilane S.; Santos, Neide, E-mail: santos_neide@yahoo.com.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Genetica

2009-07-01

There is increasing concern about airline crew members (about one million worldwide) are exposed to measurable neutrons doses. Historically, cytogenetic biodosimetry assays have been based on quantifying asymmetrical chromosome alterations (dicentrics, centric rings and acentric fragments) in mytogen-stimulated T-lymphocytes in their first mitosis after radiation exposure. Increased levels of chromosome damage in peripheral blood lymphocytes are a sensitive indicator of radiation exposure and they are routinely exploited for assessing radiation absorbed dose after accidental or occupational exposure. Since radiological accidents are not common, not all nations feel that it is economically justified to maintain biodosimetry competence. However, dependable access to biological dosimetry capabilities is completely critical in event of an accident. In this paper the dose-response curve was measured for the induction of chromosomal alterations in peripheral blood lymphocytes after chronic exposure in vitro to neutron-gamma mixes field. Blood was obtained from one healthy donor and exposed to two neutron-gamma mixed field from sources {sup 241}AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The evaluated absorbed doses were 0.2 Gy; 1.0 Gy and 2.5 Gy. The dicentric chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphase figures were analyzed for the presence of dicentrics by two experienced scorers after painted by giemsa 5%. Our preliminary results showed a linear dependence between radiations absorbed dose and dicentric chromosomes frequencies. Dose-response curve described in this paper will contribute to the construction of calibration curve that will be used in our laboratory for biological dosimetry. (author)

Estimation of gamma dose rate from hulls and shield design for the hull transport cask of Fuel Reprocessing Plant (FRP)

International Nuclear Information System (INIS)

Chandrasekaran, S.; Rajagopal, V.; Jose, M.T.; Venkatraman, B.

2012-01-01

In Fuel Reprocessing Plant (FRP), un-dissolved clad of fuel pins known as hulls are the major sources of high level solid waste. Safe handling, transport and disposal require the estimation of radioactivity as a consequent of gamma dose rate from hulls in fast reactor fuel reprocessing plant in comparison with thermal reactor fuel. Due to long irradiation time and low cooling of spent fuel, the evolution of activation products 51 Cr, 58 Co, 54 Mn and 59 Fe present as impurities in the fuel clad are the major sources of gamma radiation. Gamma dose rate from hull container with hulls from Fuel Sub Assembly (FSA) and Radial Sub Assembly (RSA) of Fuel Reprocessing Plant (FRP) was estimated in order to design the hull transport cask. Shielding computations were done using point kernel code, IGSHIELD. This paper describes the details of source terms, estimation of dose rate and shielding design of hull transport cask in detail. (author)

Avoidance behaviour and anxiety in rats irradiated with a sublethal dose of gamma-rays.

Science.gov (United States)

Tomášová, Lenka; Smajda, B; Bona, M

2011-12-01

The aim of this study was to assess, whether a sublethal dose of gamma-rays will influence the avoidance behaviour and anxiety in rats and whether the response to radiation depends on time of day of its application. Adult male Wistar rats were tested in elevated plus-maze, in hot plate test and in the light/dark box in 4 regular intervals during a day. After two weeks the animals were irradiated with a whole-body dose 6 Gy of gamma-rays. One day after irradiation the animals were repeatedly tested in the same way, as before irradiation. In the plus-maze test an increased level of anxiety was established. The irradiation significantly decreased the locomotor activity of rats, but the extent of exploratory and comfortable behaviour were not altered. After irradiation, an elevated aversion to the thermal stimulus was observed in the hot plate test. The effects of radiation were more pronounced in the light period of the day, than in the dark one. No significant differences in aversion to light were detected after irradiation. The obtained results indicate, that sublethal doses of ionizing radiation can markedly influence the reactivity of animals to adverse stimuli, their motoric activity and emotional status, as well.

Permitting of the accuracy in location of tumours and the accuracy in applying a precise dose covering in stereotactic gamma-knife treatments

International Nuclear Information System (INIS)

Ertl, A. G.

1997-01-01

The gamma-knife is a Co-60 irradiation device, permitting the location of a lesion with an accuracy of millimeters. Moreover, with the Gamma Knife it is possible to apply a precise dose covering the entire area inside the head. In order to visualize a lesion, we mostly have to resort to imaging techniques such as the MR tomography. The accuracy of locating the specific area for the stereotactic treatment was achieved with the help of a special screen plate which we designed ourselves. For determining the precise dose to be applied at the Gamma Knife, the central dose for all four collimator helmets as well as the dose distribution of the combined collimators had to be measured. In case of irradiations in prone position there may be considerable deviations compared to the dose-planning program; this we were able to demonstrate by a TLD array designed by ourselves. A more sophisticated evaluation of new dosimetry techniques - GafChromic films and BANG polymer gel - enabled us to investigate more complex irradiation patterns. (author)

Study of the Melting Latent Heat of Semicrystalline PVDF applied to High Gamma Dose Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Batista, Adriana S.M. [Departamento de Anatomia e Imagem - IMA, Universidade Federal de Minas Gerais, Av. Prof. Alfredo Balena, 190, 30130-100, Belo Horizonte, MG (Brazil); Gual, Maritza R.; Faria, Luiz O. [Centro de Desenvolvimento da Tecnologia Nuclear - CDTN, Av. Antonio Carlos 6627, C.P. 941, 31270-901, Belo Horizonte, MG (Brazil); Lima, Claubia P.B. [Departamento de Engenharia Nuclear - DEN, Universidade Federal de Minas Gerais - UFMG, Av. Antonio Carlos 6627, 31270-970 Belo Horizonte, MG (Brazil)

2015-07-01

Poly(vinylidene fluoride) homopolymers [PVDF] homopolymers were irradiated with gamma doses ranging from 0.5 to 2.75 MGy. Differential scanning calorimetry (DSC) and FTIR spectrometry were used in order to study the effects of gamma radiation in the amorphous and crystalline polymer structures. The FTIR data revealed absorption bands at 1730 and 1853 cm{sup -1} which were attributed to the stretch of C=O bonds, at 1715 and 1754 cm{sup -1} which were attributed to the C=C stretching and at 3518, 3585 and 3673 cm{sup -1} which were associated with NH stretch of NH{sub 2} and OH. The melting latent heat (LM) measured by DSC was used to construct an unambiguous relationship with the delivered dose. Regression analyses revealed that the best mathematical function that fits the experimental calibration curve is a 4-degree polynomial function, with an adjusted Rsquare of 0.99817. (authors)

Activity concentrations and mean annual effective dose from gamma-emitting radionuclides in the Lebanese diet

International Nuclear Information System (INIS)

Nasreddine, L.; Hwalla, N.; El Samad, O.; Baydoun, R.; Hamze, M.; Parent-Massin, D.

2008-01-01

Since the primary factor contributing to the internal effective dose in the human organism is contaminated food, the control of radionuclides in food represents the most important means of protection. This study was conducted to determine the levels of the dietary exposure of the Lebanese population to gamma-emitting radioisotopes. The activity concentrations of gamma-emitting radioisotopes have been measured in food samples that represent the market basket of an adult urban population in Lebanon. The artificial radionuclide 137 Cs was measured above detection limits in only fish, meat and milk-based deserts. The most abundant natural radionuclide was 40 K (31-121 Bq kg -1 ), with the highest content in fish and meat samples. The annual mean effective dose contributed by 40 K in the reference typical diet was estimated equal to 186 μSv y -1 , a value reasonably consistent with findings reported by several other countries. (authors)

Application of a radiomimetic model to the evaluation of comparative radiosensitivity of mammals to the low-dose gamma irradiation

International Nuclear Information System (INIS)

Kuchinskij, B.D.

Tested was the adequacy of a radiomimetic model (i.e. oxidized oleic acid (OOA)) for the evaluation of the comparative radiosensitivity of mammals of various types. Animals were irradiated at gamma installation with dose rate of 8 rad/min. Radiomimetic meter was introduced abdominally at the dose of 0.4 ml per 100 g of body weigth. The reactivity of an organism was estimated by the value of an average life duration. The results obtained testify to the fact that the resistance of organisms to OOA fully coincides with their resistance to the action of gamma radiation with a low dose rate, which gives evidence on the validity of using OOA for a primary estimation of radiosensitivity of various mammals

Dose calculation method with 60-cobalt gamma rays in total body irradiation

International Nuclear Information System (INIS)

Scaff, Luiz Alberto Malaguti

2001-01-01

Physical factors associated to total body irradiation using 60 Co gamma rays beams, were studied in order to develop a calculation method of the dose distribution that could be reproduced in any radiotherapy center with good precision. The method is based on considering total body irradiation as a large and irregular field with heterogeneities. To calculate doses, or doses rates, of each area of interest (head, thorax, thigh, etc.), scattered radiation is determined. It was observed that if dismagnified fields were considered to calculate the scattered radiation, the resulting values could be applied on a projection to the real size to obtain the values for dose rate calculations. In a parallel work it was determined the variation of the dose rate in the air, for the distance of treatment, and for points out of the central axis. This confirm that the use of the inverse square law is not valid. An attenuation curve for a broad beam was also determined in order to allow the use of absorbers. In this work all the adapted formulas for dose rate calculations in several areas of the body are described, as well time/dose templates sheets for total body irradiation. The in vivo dosimetry, proved that either experimental or calculated dose rate values (achieved by the proposed method), did not have significant discrepancies. (author)

Target and peripheral dose from radiation sector motions accompanying couch repositioning of patient coordinates with the Gamma Knife® Perfexion™

International Nuclear Information System (INIS)

Tran, Tuan-Anh; Wu, Vincent; Malhotra, Harish; Steinman, James P.; Prasad, Dheerendra; Podgorsak, Matthew B.

2011-01-01

The GammaPlan ™ treatment planning system (TPS) does not fully account for shutter dose when multiple shots are required to deliver a patient’s treatment. The unaccounted exposures to the target site and its periphery are measured in this study. The collected data are compared to a similar effect from the Gamma Knife ® model 4C. A stereotactic head frame was attached to a Leksell ® 16 cm diameter spherical phantom; using a fiducial-box, CT images of the phantom were acquired and registered in the TPS. Measurements give the relationship of measured dose to the number of repositions with the patient positioning system (PPS) and to the collimator size. An absorbed dose of 10 Gy to the 50% isodose line was prescribed to the target site and all measurements were acquired with an ionization chamber. Measured dose increases with frequency of repositioning and with collimator size. As the radiation sectors transition between the beam on and beam off states, the target receives more shutter dose than the periphery. Shutter doses of 3.53±0.04 and 1.59±0.04 cGy/reposition to the target site are observed for the 16 and 8 mm collimators, respectively. The target periphery receives additional dose that varies depending on its position relative to the target. The radiation sector motions for the Gamma Knife ® Perfexion ™ result in an additional dose due to the shutter effect. The magnitude of this exposure is comparable to that measured for the model 4C

Dose-effect relationships for fife shortening, tumorigenesis, and systemic injuries in mice irradiated with fission neutron or 60Co gamma radiation

International Nuclear Information System (INIS)

Ainsworth, E.J.; Fry, R.J.M.; Williamson, F.S.; Brennan, P.C.; Stearner, S.P.; Yang, V.V.; Crouse, D.A.; Rust, J.H.; Borak, T.B.

1977-01-01

The objective of this research is to provide additional data on life shortening, neoplastic and non-neoplastic diseases, and other systematic injuries necessary for the determination of dose-response relationships. The data are used to test existing predictive models and formulate new models which may assist with radiation risk assessment. Late somatic effects of fission neutrons from the JANUS reactor or from cobalt-60 gamma radiation are evaluated in young adult B6CF 1 mice that receive either a range of single doses or protracted doses at low dose rates; the protracted irradiation is administered over a 6-month period. After single doses of gamma radiation the relationship between radiation dose and percent life shortening appears linear whereas after single doses of fission spectrum neutrons a non-linear dose response is observed. These results suggest that estimates of radiation risk for fission spectrum neutrons should take into account the following: the curvilinearity of the neutron dose-response curve for life shortening, and the increased life shortening produced by neutron dose fractionation

Determination of Absorbed Dose to Water for Leksell Gamma Knife Unit

International Nuclear Information System (INIS)

Hrsak, H.

2013-01-01

Because of geometry of photon beams in Leksell Gamma Knife Unit (LGK), there are several technical problems in applying standard protocols for determination of absorbed dose to water (Dw). Currently, Dw in LGK unit, measured at the center of spherical plastic phantom, is used for dose calculation in LGK radiosurgery. Treatment planning software (LGP TPS) accepts this value as a measurement in water and since plastic phantom has higher electron density than water, this leads to systematic errors in dose calculation. To reduce these errors, a photon attenuation correction (PAC) method was applied. For that purpose, measurements of absorbed dose in a center of three different plastic phantoms with 16 cm diameter (ABS - acrylonitrile butadiene styrene, PMMA - polymethyl metacrylate, PMMA + teflon - polytetrafluoroethylene 5 mm shell) were made with ionization chamber (Semiflex, PTW Freiburg). For measured dose values, PAC to water was applied based on electron density (ED) and equivalent water depths (EWD) of the plastic phantoms. The relation between CT number and ED was determined by measuring CT number of standard CT to ED phantom (CIRS Model 062 Phantom). Absorbed dose in plastic phantoms was 2.5 % lower than calculated dose in water for ABS phantom and more than 5.5 % lower for PMMA and PMMA+teflon phantom. Calculated dose in water showed more consistent values for all three phantoms (max. difference 2.6 %). EWD for human cranial bones and brain has value close to the EWD of ABS phantom, which makes this phantom most suitable for dose measurements in clinical application. In LGK radiosurgery determination of errors related to the difference of phantom materials should not be neglected and measured dose should be corrected before usage for patient treatment dose calculation.(author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-05-23

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

Analysis of FT-IR for dosimetric characterization of poly(vinylidene fluoride - hexafluoropropylene) irradiated with high doses of gamma radiation

International Nuclear Information System (INIS)

Liz, Otavio Souza Rocha; Medeiros, Adriana de Souza

2011-01-01

Polymeric materials when exposed to ionizing radiation undergo changes such as the crosslinking and chain oxidation. Recently, the optical absorption intensities in the ultraviolet visible region (273 nm) due to radio- induction of conjugated C=C bonds in P(VDF-TrFE) copolymers has been successfully used for high dose dosimetry purposes in gamma fields ranging from 0.1 to 200 kGy. In this context, the interest of performing a systematic investigation on another fluorinated copolymer of PVDF, the (Polyvinylidene fluoride - hexa fluoro propylene) [P(VDF- HFP)] has come to light, not only for UV-VIS range but also for the near and medium infrared ranges. In this investigation FTIR and UV-Vis spectra, acquired before and after irradiation, were used to investigate the relationship between optical absorbance and delivered gamma doses ranging from 100 to 3,000 kGy. The results indicate that the absorption band at 1729 cm-1, originated by the chain oxidation through the radioinduction of C=O bonds, presents an unambiguous behavior with the delivered gamma doses in a very large extension, ranging from 0 to 1,000 kGy. This results lead to conclude that P(VDF-HFP) copolymer shows excellent dosimetric properties which make it able to be investigated as a high dose dosimeter

Calculational methods for estimating skin dose from electrons in Co-60 gamma-ray beams

International Nuclear Information System (INIS)

Higgins, P.D.; Sibata, C.H.; Attix, F.H.; Paliwal, B.R.

1983-01-01

Several methods have been employed to calculate the relative contribution to skin dose due to scattered electrons in Co-60 gamma-ray beams. Either the Klein-Nishina differential scattering probability is employed to determine the number and initial energy of electrons scattered into the direction of a detector, or a Gaussian approximation is used to specify the surface distribution of initial pencil electron beams created by parallel or diverging photon fields. Results of these calculations are compared with experimental data. In addition, that fraction of relative surface dose resulting from photon interactions in air alone is estimated and compared with data extrapolated from measurements at large source-surface distance (SSD). The contribution to surface dose from electrons generated in air is 50% or more of the total skin dose for SSDs greater than 80 cm

Geological influence on terrestrial gamma radiation dose rate in the Malaysian State of Johore

International Nuclear Information System (INIS)

Ramli, A.T.; Hussein, A.W.M.A.; Lee, M.H.

2001-01-01

Measurements of environmental terrestrial gamma radiation dose-rate (TGRD) have been made in Johore, Malaysia. The focus is on determining a relationship between geological type and TGRD levels. Data were compared using the one way analysis of variance (ANOVA), in some instances revealing significant differences between TGRD measurements and the underlying geological structure

Effects of low dose gamma irradiation on the germination and physiological activity of old red pepper (Capsicum annuum L.) seed

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Sung; Back, Myung Hwa; Lee, Hae Youn; Lee, Young Keun [KAERI, Daejeon (Korea, Republic of)

2001-12-15

To observe the stimulating effects of low dose gamma radiation on the germination and physiological activity of germinating seeds of old red pepper (Capsicum annuum L. cv, Jokwang and cv. Hongkwang), seeds were irradiated at the dose of 2{approx}50 Gy. The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage of induction. The germination rate at 7 days after sowing in Jokwang and Hongkwang cultivar was high as 74% and 11% at 4 Gy and 8 Gy irradiation group, respectively. The seedling height of Jokwang cultivar was noticeably high at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy Irradiation group. The protein contents of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at the late stage of induction and that of Hongkwang cultivar at the early stage of induction. Catalase and peroxidase activities of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy irradiation group.

Effect of superlarge dose of gamma radiation on the rat cerebral cortex (ultrastructural aspects)

International Nuclear Information System (INIS)

Abdrakhmanov, A.A.; AN Kazakhskoj SSR, Alma-Ata

1988-01-01

Puberal Wistar line mall rats (180-210 g) were subjected to single whole-body gamma irradiation with 150 Gy dose and 75 Gy/min dose rate. Electron-microscopic investigation into dynamics of sensory-motor cortex ultrastructural changes during 24 hours after irradiation is conducted. Along with destructive changes compensator-reduction processes are developed in brain tissue at this period. Already during the first hours after irradiation the neutron ultrastructure change dynamics has been determined, alongside with direct radiation effect, by indirect effects juries of neuroglia and microcirculatory channel

Effect of superlarge dose of gamma radiation on the rat cerebral cortex (ultrastructural aspects)

Energy Technology Data Exchange (ETDEWEB)

Abdrakhmanov, A A

1988-06-01

Puberal Wistar line mall rats (180-210 g) were subjected to single whole-body gamma irradiation with 150 Gy dose and 75 Gy/min dose rate. Electron-microscopic investigation into dynamics of sensory-motor cortex ultrastructural changes during 24 hours after irradiation is conducted. Along with destructive changes compensator-reduction processes are developed in brain tissue at this period. Already during the first hours after irradiation the neutron ultrastructure change dynamics has been determined, alongside with direct radiation effect, by indirect effects juries of neuroglia and microcirculatory channel.

Investigation of dose distribution in mixed neutron-gamma field of boron neutron capture therapy using N isopropylacrylamide gel

Energy Technology Data Exchange (ETDEWEB)

Bavarmegin, Elham; Sadremomtaz, Alireza [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Khalafi, Hossein; Kasesaz, Yaser [Dept. of Physics, University of Guilan, Rasht (Iran, Islamic Republic of); Khajeali, Azim [Medical Education Research Center, Tabriz (Iran, Islamic Republic of)

2017-02-15

Gel dosimeters have unique advantages in comparison with other dosimeters. Until now, these gels have been used in different radiotherapy techniques as a reliable dosimetric tool. Because dose distribution measurement is an important factor for appropriate treatment planning in different radiotherapy techniques, in this study, we evaluated the ability of the N-isopropylacrylamide (NIPAM) polymer gel to record the dose distribution resulting from the mixed neutron-gamma field of boron neutron capture therapy (BNCT). In this regard, a head phantom containing NIPAM gel was irradiated using the Tehran Research Reactor BNCT beam line, and then by a magnetic resonance scanner. Eventually, the R2 maps were obtained in different slices of the phantom by analyzing T2-weighted images. The results show that NIPAM gel has a suitable potential for recording three-dimensional dose distribution in mixed neutron-gamma field dosimetry.

Study of {gamma}'s in Naiade; Etude des gamma de Naiade

Energy Technology Data Exchange (ETDEWEB)

Millot, J P; Rastoin, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Following a study of the gamma sources, the flux of gamma of different energies in the swimming pool is investigated. The biological dose can thus be obtained by calculation, and compared with the results given by photographic plates. The influence of photoneutrons is estimated by calculation, and research is being carried out on their influence on the thermal neutron flux curve on the axis of the uranium plate, with the plate emitting neutrons and with the plate protected by boral. (author) [French] Apres l'etude des sources de gamma, l'on etudie le flux de gamma de differentes energies dans la piscine. La dose biologique peut etre obtenue ainsi par le calcul et comparee avec les resultats donnes par les plaques photographiques. L'influence des photoneutrons est estimee par le calcul et l'on recherche leur influence sur la courbe de flux de neutrons thermiques sur l'axe de la plaque d'uranium, la plaque emettant des neutrons et la plaque protegee par du boral. (auteur)

Induced mitotic gynogenesis in common carp (Cyprinus carpio L.), optimizing irradiation dose of X- and gamma-ray

International Nuclear Information System (INIS)

Yousefian, M.; Amirinia, C.; Bercsenyi, M.; Horvath, L.

1997-01-01

Mitotic gynogenesis was induced in common carp, Cyprinus carpio L., in hatchery and laboratory conditions, using 60Co gamma-ray and X-ray for inactivation of sperm DNA and a subsequent heat shock for inducing endomitosis. The parameter examined was the dose of irradiation in the range of 70-140 Krad. Carp spermatozoa irradiated by 70-100 Krad doses showed higher motility and fertilization ability than the ones irradiated by 110-140 Krad. Sperm treated with doses of 70-90 Krad showed the same fertility rate, but lower survival rate at embryo stage compared with 100 Krad. The shock temperature and duration applied in these experiments for restoration of diploidy level were 40 degrees C plus/minus 0.1 and 2 min., respectively. The highest frequency of mitotic gynogenetic larvae was achieved by 100 Krad 60Co gamma ray at 34 min. after fertilization, - up to 12.2 percent (at 23 degrees C incubating temperature)

Real time monitoring automation of dose rate absorbed in air due to environmental gamma radiation

International Nuclear Information System (INIS)

Dominguez Ley, Orlando; Capote Ferrera, Eduardo; Carrazana Gonzalez, Jorge A.; Manzano de Armas, Jose F.; Alonso Abad, Dolores; Prendes Alonso, Miguel; Tomas Zerquera, Juan; Caveda Ramos, Celia A.; Kalber, Olof; Fabelo Bonet, Orlando; Montalvan Estrada, Adelmo; Cartas Aguila, Hector; Leyva Fernandez, Julio C.

2005-01-01

The Center of Radiation Protection and Hygiene (CPHR) as the head institution of the National Radiological Environmental Surveillance Network (RNVRA) has strengthened its detection and response capacity for a radiological emergency situation. The measurements of gamma dose rate at the main point of the RNVRA are obtained in real time and the CPHR receives the data coming from those points in a short time. To achieve the operability of the RNVRA it was necessary to complete the existent monitoring facilities using 4 automatic gamma probes, implementing in this way a real time measurement system. The software, GenitronProbe for obtaining the data automatically from the probe, Data Mail , for sending the data via e-mail, and Gamma Red , for receiving and processing the data in the head institution ,were developed

Gamma factors of an ambulatory source; Factores gamma de una fuente ambulatoria

Energy Technology Data Exchange (ETDEWEB)

Arcos P, A; Vega C, H R; Manzanares A, E; Salas L, M A; Hernandez D, V M [Unidades Academicas de Estudios Nucleares e Ingenieria Electrica, Universidad Autonoma de Zacatecas, C. Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Barquero, R [Hospital Universitario del Rio Hortega, E-47010 Valladolid (Spain)

2007-07-01

Some of the procedures for diagnostic or treatment used in the medicine use radioactive materials as the I{sup 131}. By means of Monte Carlo methods were calculated the doses in the internal organs of a woman, with three months of pregnancy, due to the radioiodine captured by her thyroid, as well as to 1 meter of the gland. A three-dimensional mathematical model of the body of a woman was used and by means of Monte Carlo, the radioiodine photons were transported isotropically from the thyroid toward the whole body and was calculated the absorbed dose by their internal organs, also the Kerma in air (K) was determined and the environmental equivalent dose (H{sup *}(10)) at 1 m of the gland. Two activity factors at dose were determined, Gamma Factors that it allows to estimate the dose that the patient produces to people to its around. Of the gamma radiation that emits the I{sup 131} in the thyroid was found that the thymus receives the biggest dose while the uterus is the organ that smaller dose receives. The determined gamma factors were: {gamma}{sub KAire} = 56 {mu}Gy-m{sup 2}-h{sup -1}-GBq{sup -1}, and {gamma}{sub H}{sup *}{sub (10)} = 73 {mu}Sv-m{sup 2}-h{sup -1}-GBq{sup -1}. The distribution of the absorbed dose by the internal organs is attributed to the relative distance among the thyroid and the other organs, to the inter-organs shielding, its size and to its elementary composition. The {gamma}{sub KAire} and {gamma}{sub H}{sup *}{sub (10)} factors allow to estimate the exposure that the patient produces on the personnel to its around. With this, the nuclear medicus, the medical physicist or the one responsible of the radiological safety in the hospital can give more precise indications on the behavior of people around the patient. (Author)