Determination of surface dose rate from a 9 0 Sr ophthalmic applicator

1990 ◽  
Vol 17 (3) ◽  
pp. 416-421 ◽  
Author(s):  
Mohamed M. Ali ◽  
Faiz M. Khan
Keyword(s):  
Dose Rate ◽  
Surface Dose

Determination of surface dose rate of indigenous 32 P patch brachytherapy source by experimental and Monte Carlo methods

2015 ◽  
Vol 103 ◽  
pp. 120-127 ◽  
Author(s):  
Sudhir Kumar ◽  
P. Srinivasan ◽  
S.D. Sharma ◽  
Sanjay Kumar Saxena ◽  
A.K. Bakshi ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Dose Rate ◽  
Monte Carlo Methods ◽  
Surface Dose ◽  
Brachytherapy Source

Windowless extrapolation chamber measurement of surface dose rate from a 90 Sr/ 90 Y ophthalmic applicator

2018 ◽  
Vol 108 ◽  
pp. 34-40 ◽  
Author(s):  
Jon B. Hansen ◽  
Wesley S. Culberson ◽  
Larry A. DeWerd
Keyword(s):  
Dose Rate ◽  
Surface Dose ◽  
Extrapolation Chamber

scholarly journals Dating mortar by optically stimulated luminescence: A feasibility study

2011 ◽  
Vol 38 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Christian Goedicke
Keyword(s):  
Dose Rate ◽  
Short Range ◽  
Optically Stimulated Luminescence ◽  
Radioactive Equilibrium ◽  
Lime Mortar ◽  
Modulation Techniques ◽  
Single Grain ◽  
Optical Bleaching ◽  
Number Of Publications

AbstractQuartz is the datable component in mortar. Although its luminescence properties are very well studied, the problem of mortar dating arises from a low level of optical bleaching. In order to reduce the time consuming efforts for dating lime mortar in monuments by optically stimulated luminescence, we investigated the most suitable methods of dose and dose rate determination, and we explored tests which are suitable to predict the datability of a given material. Reverting to the large number of publications on sedimentary partially bleached quartz we found linear modulation techniques especially useful, equally we also recommend the determination of the level of optical depletion before starting analyses. Single grain analysis is regarded as an ultimate but infallible tool to date very poorly bleached quartz from mortar. Dose rate measurements need to take into account the radioactive equilibrium of the uranium decay and the short range inhomogeneity of the environmental gamma radiation field: gamma spectrometry and on-site TLD measurements are best suited.

Determination of surface dose and the effect of bolus to surface dose in electron beams

2003 ◽  
Vol 28 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Basri Günhan ◽  
Gönül Kemikler ◽  
Ayse Koca
Keyword(s):  
Electron Beams ◽  
Surface Dose

An Automated Non-Destructive Assay System for the Measurement and Characterization of Radioactive Waste

2003 ◽  
Author(s):  
J. A. Mason ◽  
W. Hage ◽  
R. Price ◽  
A. C. Tolchard ◽  
A. C. N. Towner
Keyword(s):  
Radioactive Waste ◽  
Dose Rate ◽  
Matrix Effects ◽  
Fissile Material ◽  
Surface Dose ◽  
Heavy Duty ◽  
Bar Code ◽  
Non Destructive ◽  
Waste Drums

The paper describes an automated non-destructive assay (NDA) system for the measurement and characterization of radioactive waste. The Waste Characterisation System (WCS) can be adapted to measure a variety of drum sizes: 60, 220 (55 gallon) and 440 liter, the latter with a maximum weight of 1500 kg (1.5 tonnes). The NDA system includes a Tomographic Segmented Gamma Scanner (TSGS) and an active/passive neutron Differential Die-away (DDA or DDT). The system can assay a wide variety of waste types in a range of waste matrices. The assay stations are linked by a heavy duty roller conveyor which incorporates a 20 drum buffer store, a load cell (built into the conveyor), bar code readers and a dose rate measurement station. The Tomographic Segmented Gamma Scanner (TSGS) combines conventional high resolution gamma spectrometry and a tranission source to interrogate a waste drum in vertical slices (segments) as for Segmented Gamma Scanner (SGS) measurements. However, in the case of the TSGS, while the drum is rotated, it is also moved in the horizontal direction leading to an enhanced ability to correct the gamma ray energies, from the nuclides of interest, for the attenuation of the matrix. The TSGS can also be operated as a conventional SGS for the measurement of homogeneous waste drums. The DDA is a very sensitive active neutron interrogation method that uses thermalised neutrons from a pulsed source within the chamber to irradiate a waste drum. Prompt neutrons from fissile material present in the waste (e. g. 239Pu, 235U) are detected and provide a measure of the fissile content in the drum. In passive mode, the DDA determines the even Pu nuclides exhibiting significant spontaneous fission (e.g. 240Pu). Measurement accuracy depends on correction algorithms to compensate for self-shielding and matrix effects in waste drums containing hydrogenous materials. In addition, the DDA will be provided with the Fission-Fission Neutron Correlation Analysis System (FFnC) which is an absolute technique eliminating the need for matrix dependent mass calibrations, and allowing separate U and Pu determination using delayed neutron counting. The FFnC technique will be tested for the first time on the WCS. The NDA system incorporates integrated stations to determine the weight and dose rate of each drum, the former built into the conveyor the latter as part of the TSGS. Six Geiger Muller tubes measure the surface dose at three positions on the drum side, one at 1 metre from the drum and one each measuring the surface dose of the top and bottom of the drum. The assay instruments are linked to a heavy duty conveyor system onto which up to 20 waste drums can be loaded for delivery to the various measurement stations, thus permitting unattended, automated operation. Once measured, the drums remain on the conveyer in a holding system waiting to be unloaded. Automation is provided using a programmable logic controller (PLC) and associated computers. A central computer and associated software is used for data acquisition and management.

Calculation of the Nuclear Material Inventory in a Sealed Vault by 3D Radiation Mapping

2013 ◽  
Author(s):  
Ian Adsley ◽  
Yevgeniy Tur ◽  
Alexander Klepikov ◽  
David Wells
Keyword(s):  
Dose Rate ◽  
Nuclear Material ◽  
Source Distribution ◽  
Nuclear Materials ◽  
Manipulator Arm ◽  
Enriched Uranium ◽  
Rate Profile ◽  
Global Threat ◽  
The Uk

The paper relates to the determination of the amount of nuclear material contained in a closed, concrete lined vault at the Aktau fast breeder reactor in Kazakhstan. This material had been disposed into the vault after examination in an experimental hot cell directly above the vault. In order to comply with IAEA Safeguards requirements it was necessary to determine the total quantities of nuclear materials — enriched uranium and plutonium — that were held with Kazakhstan. Although it was possible to determine the inventory of all of the accessible nuclear material — the quantity remaining in the vault was unknown. As part of the Global Threat Reduction Programme the UK Government funded a project to determine the inventory of these nuclear materials in this vault. This involved drilling three penetrations through the concrete lined roof of the vault; this enabled the placement of lights and a camera into the vault through two penetrations; while the third penetration enabled a lightweight manipulator arm to be introduced into the vault. This was used to provide a detailed 3D mapping of the dose rate within the vault and it also enabled the collection of samples for radionuclide analysis. The deconvolution of the 3D dose rate profile within the vault enabled the determination of the gamma emitting source distribution on the floor and walls of the vault. The samples were analysed to determine the fingerprint of those radionuclides producing the gamma dose — namely 137Cs and 60Co — to the nuclear materials. The combination of the dose rate source terms on the surfaces of the vault and the fingerprint then enabled the quantities of nuclear materials to be determined. The project was a major success and enabled the Kazakhstan Government to comply with IAEA Safeguards requirements. It also enabled the UK DECC Ministry to develop a technology of national (and international) use. Finally the technology was well received by IAEA Safeguards as an acceptable methodology for future studies.

Primary yields and mechanism in the radiolysis of gaseous ammonia

1969 ◽  
Vol 47 (16) ◽  
pp. 3007-3016 ◽  
Author(s):  
C. Willis ◽  
A. W. Boyd ◽  
O. A. Miller
Keyword(s):  
Dose Rate ◽  
Rate Constant ◽  
High Dose Rate ◽  
Radical Reactions ◽  
Gaseous Ammonia ◽  
High Dose ◽  
Ammonia Vapor ◽  
Radical Product ◽  
Very High

Ammonia vapor has been irradiated with single pulses of electrons at a very high dose rate (1027 eV g−1 s−1) with a Febetron 705. At this dose rate radical–product reactions are not significant. In pure ammonia, hydrogen, nitrogen, and hydrazine are produced and the yields found at 1027 eV g−1 s−1 are: G(H2) = 3.58 ± 0.08; G(N2) = 1.00 ± 0.05; G(N2H4) = 0.58 ± 0.05. The yields are independent of pressure from 1 to 5 atm and of temperature between 20 and 200 °C. Above 250 °C the yields of all three products increase significantly and this is due to reaction [1] competing with radical–radical reactions.[Formula: see text]A rate constant for this reaction has been determined,[Formula: see text]Product yields have been measured for ammonia–propene mixtures. These yields have allowed determination of the primary radiation yields GNH = 0.74; [Formula: see text]; GH = 4.8; and G(−NH3) = 5.4.

A New Approach for the Determination of Dose Rate and Radioactivity for Detected Gamma Nuclides Using an Environmental Radiation Monitor Based on an NaI(Tl) Detector

2017 ◽  
Vol 113 (4) ◽  
pp. 304-314 ◽  
Author(s):  
Young-Yong Ji ◽  
Chang-Jong Kim ◽  
Kyo-Sun Lim ◽  
Wanno Lee ◽  
Hyon-Sock Chang ◽  
...  
Keyword(s):  
Dose Rate ◽  
Environmental Radiation ◽  
New Approach ◽  
Radiation Monitor
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