scholarly journals A union neutron-gamma logging method for determination of uranium-radium disequilibrium coefficient

2020 ◽  
Vol 35 (2) ◽  
pp. 103-108
Author(s):  
Rui Chen ◽  
Cheng-Yuan Luo ◽  
Hai-Tao Wang ◽  
Zhi-Feng Liu ◽  
Xiong-Jie Zhang ◽  
...  
Keyword(s):  
Count Rate ◽  
Gamma Ray ◽  
Uranium Content ◽  
Fission Neutron ◽  
Characteristic Peak ◽  
Prompt Fission ◽  
Logging Tool ◽  
Peak Count ◽  
Good Agreement

Owing to the influence of continuous running of ground water, the uranium atoms can be separated physically from their daughters for the reason of different solubilities and the uranium deposit often shows the disequilibrium feature between uranium and its daughter products (radium principally). It is important, when spectral gamma ray logging, to quantify the uranium content which can cause inaccuracy of the result. This paper, based on spectral ? ray logging method, proposes a neutron-gamma logging method to determine the coefficient of uranium-radium disequilibrium. In this method, characteristic peak count rate of uranium is taken from prompt fission neutron logging, whereas characteristic peak count rate of radium, thorium and potassium are taken from spectral gamma ray logging. Based on this method, the union logging tool including epithermal neutron, thermal neutron, and gamma detector along with D-T generator, have been developed. The experimental results, in standard model wells, show that this method is in good agreement within 7% in core assay results. It shows that the union neutron-? logging method can be used for field uranium logging jobs.

Modeling detector response in airborne gamma‐ray spectrometry

Geophysics ◽  
1999 ◽  
Vol 64 (5) ◽  
pp. 1378-1392 ◽  
Author(s):  
Stephen Billings ◽  
Jens Hovgaard
Keyword(s):  
Count Rate ◽  
Gamma Ray ◽  
Solid Angle ◽  
Azimuthal Angle ◽  
Geometrical Model ◽  
Detector Response ◽  
Gamma Ray Spectrometry ◽  
Uniform Model ◽  
Detector Model ◽  
Peak Count

A geometrical detector model of airborne gamma‐ray spectrometry is presented for data acquired using a rectangular detector of arbitrary dimensions. The detector response is modeled by calculating variations in solid angle and detector thickness for sources at different orientations. This gives the total count rate, which is then multiplied by a factor, assumed independent of orientation, to give the peak count rate. The model shows excellent agreement with experimental data collected using a 4.2-liter detector and with Monte Carlo simulations of a 16.8-liter detector. Results for the 4.2-liter crystal showed significant asymmetry. However, for a typical airborne system, with a 16.8-liter crystal, the asymmetry was weak because the detector had about the same solid angle and thickness at any azimuthal angle. The point spread function for the geometrical detector model differed significantly from a uniform detector model, the latter predicting a lower spatial resolution. This implies that surveys designed on the uniform assumption may undersample the signal between flight lines. For example, at 60 m elevation, the area that contributes 90% of the thorium signal is predicted to be 10.9 hectares (ha) for the uniform model and only 7.6 ha for the geometrical model. The model can be extended to incorporate aircraft velocity by convolving the stationary model with a rectangular function. Aircraft velocity can have a substantial influence on the modeled response if long integration times permit significant displacement of sources relative to the height of the aircraft.

scholarly journals Determination of Boron Content in Volcanic Rocks by Using Neutron-induced Prompt .GAMMA.-Ray. Correction of Count Rate Fluctuation Using Silicon Internal Standard.

RADIOISOTOPES ◽  
1998 ◽  
Vol 47 (10) ◽  
pp. 735-744 ◽  
Author(s):  
Takashi SANO ◽  
Takaaki FUKUOKA ◽  
Toshiaki HASENAKA ◽  
Chushiro YONEZAWA ◽  
Hideaki MATSUE ◽  
...  
Keyword(s):  
Count Rate ◽  
Boron Content ◽  
Gamma Ray ◽  
Volcanic Rocks ◽  
Internal Standard ◽  
Prompt Gamma ◽  
Rate Fluctuation

scholarly journals Determination of Gamma-Ray Shielding Parameters for Concretes and Dosimeters Using MCNPX

2020 ◽  
Vol 8 (1) ◽  
pp. 73-79
Author(s):  
V. P. Singh ◽  
Huseyin Ozan Tekin
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Simulation Method ◽  
Radiological Protection ◽  
Simulation Tool ◽  
Alternative Method ◽  
Standard Geometry ◽  
Good Agreement

Gamma-ray shielding parameter for some concretes and dosimeters having large scale applications in radiological protection are presented using MCNPX (version 2.4.0) at different energies. The MCNPX results are compared with experimental, MCNP and XCOM data, and good agreement is being noted. Present study indicates that MCNPX simulation method is suitable and reliable simulation tool to be used as an alternative method for the investigation of gamma-ray interaction. The present geometry can be used as standard geometry for MCNPX simulation for low- as well as high-Z materials.

Analysis of Heat Flow Data–Vertical Variations of Heat Flow and Heat Producing Elements in Sediments

1975 ◽  
Vol 12 (6) ◽  
pp. 996-1005 ◽  
Author(s):  
V. M. Hamza ◽  
A. E. Beck
Keyword(s):  
Heat Flow ◽  
Heat Production ◽  
Gamma Ray ◽  
Detailed Examination ◽  
Uranium Content ◽  
Thermal Resistivity ◽  
Geochemical Reactions ◽  
Vertical Variations ◽  
Heat Flow Variations

Gamma ray spectrometric techniques have been used for the determination of uranium, thorium and potassium contents from cores selected at 3 to 4 m intervals from a 600 m deep borehole in sedimentary formations and the results compared with a similarly detailed examination of heat flow, and some physical properties, from the same borehole.The results indicate a broad positive correlation between thermal resistivity and some of the radio-element parameters and between heat flow and heat production. The heat production variations down the borehole are not quantitatively sufficient to explain the observed heat flow variations. The uranium series appears to be in radioactive equilibrium even in those sections where the uranium content is low, the porosity relatively high and the heat flow low; it is therefore concluded that the depletion of uranium is due to an ancient rather than a recent leaching process and that it is unlikely that the heat flow variations along the borehole are due to existing or recent underground waterflows. Long term geochemical reactions are now thought to be the most likely explanation of the heat flow variations.

scholarly journals Prompt Fission Gamma-Ray Measurements at UML Research Reactor

2020 ◽  
Vol 242 ◽  
pp. 01009
Author(s):  
Razvan Stanescu ◽  
Hadrick Green ◽  
Toby Morris ◽  
Gencho Rusev ◽  
Marian Jandel
Keyword(s):  
Gamma Rays ◽  
Research Reactor ◽  
Gamma Ray ◽  
Fission Neutron ◽  
Pulse Shape Discrimination ◽  
Prompt Gamma ◽  
Fission Reaction ◽  
Induced Fission ◽  
Enriched Uranium ◽  
Prompt Fission

Neutron-induced fission of 235U was studied at the thermal column of the UMass Lowell 1 MW Research Reactor. A collimated, 2.25-inch diameter beam of thermal neutrons with the flux of ~5x105 n/cm2/sec induced fission reaction on a plate of low-enriched uranium with the areal density ~25 mg/cm2 of 235U. We have used the prompt fission-neutron tagging method to identify the fission reaction in the off-line analysis. The method employs the pulse-shape discrimination of neutrons and gamma-ray events in stilbene scintillator and enables identification of coincidence events of prompt fission gamma-rays and prompt fission neutrons in coincidence time intervals less than 20-30 ns. The prompt gamma-ray radiation was detected using two co-linear NaI(Tl) detectors. The measured spectra of prompt-fission gamma rays between 150 keV and 6 MeV are presented. The results from these initial measurements demonstrate the feasibility of the experimental method. Future measurements with extended arrays of detectors are planned.

scholarly journals DETERMINATION OF THE URANIUM CONTENT IN SOME SOIL SAMPLES FROM AJAOKUTA, KOGI STATE: NIGERIA

2019 ◽  
Vol 7 (9) ◽  
pp. 252-258
Author(s):  
Aruwa Arome ◽  
Philibus Musa Gyuk ◽  
Achor Mathias Ogwo ◽  
Isah Suleiman
Keyword(s):  
Activity Concentration ◽  
Pulse Height ◽  
Uranium Content ◽  
Mean Value ◽  
Soil Samples ◽  
Pulse Height Analyzer ◽  
The World ◽  
The Mean ◽  
Good Agreement

This work present the Uranium (238U) content in soil samples collected in Ajaokuta from some villages was been determined. The measurement of the soil Uranium activity concentration were made using a multi–channel pulse height analyzer (Camberra series 10 plus) coupled to a 76.2mm x 76.2mm NaI (TI) scintillation detector. 2.93)The mean Uranium content in the analyzed samples was found to be (44.26 Bq/kg which is higher than the world mean value of 35Bq/kg. The results were in good agreement with others for soils from region which is considered as normal or slightly high in radioactivity level.

scholarly journals Theoretical and experimental determination of mass attenuation coefficients of lead-based ceramics and their comparison with simulation

2016 ◽  
Vol 31 (2) ◽  
pp. 142-149 ◽  
Author(s):  
Alireza Vejdani-Noghreiyan ◽  
Elham Aliakbari ◽  
Atiyeh Ebrahimi-Khankook ◽  
Mahdi Ghasemifard
Keyword(s):  
Gamma Ray ◽  
Mass Attenuation Coefficient ◽  
X Ray Diffraction ◽  
Attenuation Coefficients ◽  
X Ray ◽  
Simulation Results ◽  
Theoretical Results ◽  
Good Agreement ◽  
Mass Attenuation

Mass attenuation coefficient of lead-based ceramics have been measured by experimental methods and compared with theoretical and Monte Carlo simulation results. Lead-based ceramics were prepared using mixed oxide method and the X-ray diffraction analysis was done to evaluate the crystal structure of the produced handmade ceramics. The experimental results show good agreement with theoretical and simulation results. However at two gamma ray energies, small differences between experimental and theoretical results have been observed. By adding other additives to ceramics and observing the changes in the shielding properties such as flexibility, one can synthesize and optimize ceramics as a neutron shield.

AN EMPIRICAL APPROACH TO THE DETERMINATION OF POROSITY, SHALE PERCENTAGE, AND PERMEABILITY OF PERMIAN SANDSTONES IN THE COOPER BASIN, SOUTH AUSTRALIA

1976 ◽  
Vol 16 (1) ◽  
pp. 111
Author(s):  
C. R. Porter
Keyword(s):  
Gamma Ray ◽  
South Australia ◽  
Core Values ◽  
Empirical Approach ◽  
Good Agreement ◽  
Cooper Basin

Because of the limited yet adequate logging program run in Cooper Basin wells, porosity has been the most difficult parameter to calculate on a zone-by-zone basis. Empirically derived porosities from a gamma-ray (GK)-sonie (Δt) cross-plot show good agreement with core values of porosity. Furthermore shale percentages calculated from these porosities are in good agreement with shale values derived from crossplot techniques involving sonic, density and neutron log response parameters. An approximation of permeability may also be derived from a further simplified chart.

Measurement of Selected Differential Cross Sections in 235U Spectrum

2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Nicola Burianová ◽  
Michal Košt´ál ◽  
Martin Schulc ◽  
Jan Šimon ◽  
Martin Mareček ◽  
...  
Keyword(s):  
Cross Sections ◽  
Nuclear Data ◽  
Reaction Rates ◽  
Fission Neutron ◽  
Data Libraries ◽  
Nuclear Data Libraries ◽  
Prompt Fission Neutron Spectrum ◽  
Prompt Fission ◽  
Prompt Fission Neutron ◽  
Good Agreement

This paper describes the measurement of 55Mn(n,2n) and 127I(n,2n) reaction rates in a well-defined reactor field in a special core of LR-0 reactor. The reaction rates were derived using gamma-spectrometry by measuring gamma activities of irradiated MnO2 and NaI samples at a high purity germanium (HPGe) detector. The spectral average cross section (SACS) in 235U prompt fission neutron spectrum (PFNS) was experimentally determined to be 0.2393 ± 0.015 × 10−3 b for 55Mn and 1.2087 ± 0.052 × 10−3 b for 127I. These obtained results were compared with calculations by MCNP6 code using ENDF/B VII.1, ENDF/B VII, JEFF-3.1, JEFF-3.2, JENDL-3.3, JENDL-4, ROSFOND- 2010, CENDL-3.1, and IRDFF nuclear data libraries. In a case of 55Mn, a good agreement with ENDF/B VII.1, JEFF 3.1, JENDL 3.3, JENDL 4, ROSFOND, and CENDL 3.1 nuclear data libraries was found, where C/E−1 is 0.1%, while IRDFF underestimated by about 15.8%. In the case of 127I, more significant discrepancies were found, where JENDL 3.3 and JENDL 4 overestimate the result by about 31.3%.

Enrichment analysis of uranium in uranium oxide by gamma-ray spectrometry without using calibration standards

2000 ◽  
Vol 88 (2) ◽  
Author(s):  
Y. Nir-El
Keyword(s):  
Gamma Rays ◽  
Uranium Oxide ◽  
Gamma Ray ◽  
Enrichment Analysis ◽  
Gamma Ray Spectrometry ◽  
Uranium Enrichment ◽  
Calibration Standards ◽  
Certified Values ◽  
Good Agreement

An analytical method for the determination of uranium enrichment in uranium oxide without using any calibration standards is described. Very good agreement between the measured and certified values was obtained in the analysis of a Standard Reference Material. Precise energies and emission probabilities were derived for two weak gamma-rays of

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