scholarly journals VALIDATION OF AXIAL VOID PROFILE MEASURED BY NEUTRON NOISE TECHNIQUES IN CROCUS

2021 ◽  
Vol 247 ◽  
pp. 08004
Author(s):  
Mathieu Hursin ◽  
Oskari Pakari ◽  
Gregory Perret ◽  
Pavel Frajtag ◽  
Vincent Lamirand ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Experimental Techniques ◽  
Water Tank ◽  
Heterogeneous Distribution ◽  
Low Contrast ◽  
Joint Project ◽  
Neutron Noise ◽  
Gamma Ray Attenuation ◽  
Paul Scherrer ◽  
École Polytechnique

Recently a joint project has been carried out between the Paul Scherrer Institut, the Ecole Polytechnique Federale de Lausanne and swissnuclear, an industrial partner, in order to determine the axial void distribution in a channel installed in the reflector of the zero power research reactor CROCUS, using neutron noise techniques. The main objective of the present paper is to report on the validation of the results against an alternative measurement technique using gamma-ray attenuation and simulations with the TRACE code. For the gamma-ray attenuation experiments, the channel used in CROCUS is installed out of the core in a Plexiglass water tank. The source and detector are fixed and the channel is moved axially to keep the geometry of the source/detector arrangement untouched. This is key to measure the void effect by gamma attenuation due to the low contrast of this technique. The paper compares the experimental results obtained with both techniques, with the outcomes of simulations carried out with the TRACE code. Even though the quantitative void fraction estimations are not consistent, the trends obtained with the simulation and experimental techniques are the same. The discrepancies between the various experimental techniques and the simulation outcomes are related to the heterogeneous distribution of the water-air mixture in the radial sections of the channel.

Introduction: Seventy Years of Calorimetry

2018 ◽  
Author(s):  
Richard Wigmans
Keyword(s):  
Gamma Ray ◽  
Experimental Techniques ◽  
Gamma Ray Detectors ◽  
History Of

The history of calorimetry is described, starting with the small scintillating crystals that were used as nuclear gamma ray detectors, to the multi-ton instruments that form the heart of modern experiments at colliding-beam accelerators. The different experimental techniques that are used for generating signals are reviewed.

scholarly journals Gamma-Ray Attenuation to Evaluate Soil Porosity: An Analysis of Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Luiz F. Pires ◽  
André B. Pereira
Keyword(s):  
Gamma Ray ◽  
Particle Density ◽  
Pore Space ◽  
Physical Property ◽  
Soil Bulk Density ◽  
Soil Porosity ◽  
Porous System ◽  
Soil Pore Space ◽  
Gamma Ray Attenuation ◽  
Dry Soil

Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations ofϕare necessary due to the importance of this physical property in several fields of natural sciences. In the current work, two methods to evaluateϕwere analyzed by means of gamma-ray attenuation technique. The first method uses the soil attenuation approach through dry soil and saturated samples, whereas the second one utilizes the same approach but taking into account dry soil samples to assess soil bulk density and soil particle density to determineϕ. The results obtained point out a good correlation between both methods. However, whenϕis obtained through soil water content at saturation and a 4 mm collimator is used to collimate the gamma-ray beam the first method also shows good correlations with the traditional one.

Gamma-ray attenuation behaviors of hematite doped polymer composites

2020 ◽  
Vol 129 ◽  
pp. 103504 ◽  
Author(s):  
Mehmet Fatih Turhan ◽  
Ferdi Akman ◽  
Hasan Polat ◽  
Mustafa Recep Kaçal ◽  
İskender Demirkol
Keyword(s):  
Polymer Composites ◽  
Gamma Ray ◽  
Gamma Ray Attenuation ◽  
Doped Polymer

Measurement of pulmonary edema in intact dogs by transthoracic gamma-ray attenuation

1979 ◽  
Vol 47 (6) ◽  
pp. 1228-1233 ◽  
Author(s):  
D. S. Simon ◽  
J. F. Murray ◽  
N. C. Staub
Keyword(s):  
Pulmonary Edema ◽  
Time Course ◽  
Gamma Ray ◽  
High Sensitivity ◽  
Lung Edema ◽  
Lung Water ◽  
Vascular Congestion ◽  
Isolated Lung ◽  
Wide Range ◽  
Gamma Ray Attenuation

We evaluated the attenuation of the 122 keV gamma ray of cobalt-57 across the thorax of anesthetized dogs as a method for following the time course of lung water changes in acute pulmonary edema induced by either increased microvascular permeability or increased microvascular hydrostatic pressure. The gamma rays traversed the thorax centered on the seventh rib laterally where the lung mass in the beam path was greatest. Calibration measurements in isolated lung lobes demonstrated the high sensitivity and inherent accuracy of the method over a wide range of lung water contents. In control dogs reproducibility averaged +/-3%. Increased permeability edema led to large rapid increases in the transthoracic gamma ray attenuation (TGA), while increased pressure caused an immediate, modest increase in TGA (vascular congestion) followed by a slow further increase over 2 h. There was a fairly good correlation between the increase in extravascular lung water and the change in TGA. The method is simple, safe, and noninvasive and appears to be useful for following the time course of lung water accumulation in generalized lung edema in anesthetized animals.

Effect of Particle Size of W-Brass Composite on Gamma-Ray Absorption Coefficient

2015 ◽  
Vol 754-755 ◽  
pp. 19-23
Author(s):  
Kahtan S. Mohammed ◽  
Ali Basheer Azeez ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Azmi B. Rahmat
Keyword(s):  
Particle Size ◽  
Absorption Coefficient ◽  
Gamma Ray ◽  
Vickers Microhardness ◽  
Volume Fraction ◽  
Milled Powder ◽  
Microstructural Characterization ◽  
Effect Of Particle Size ◽  
Gamma Ray Attenuation ◽  
Attenuation Values

In this study, the dependence of gamma-ray absorption coefficient on amount and particle size of tungsten (W) in W-brass sintered compacts was investigated. To attain this goal, two sets of different W wt. % were prepared (W 65wt. %, W75wt. % and W85 wt. %). One set has compacts of as received powder and the other set has compacts of ball milled powder. The results showed that gamma-ray attenuation coefficient is inversely proportional to the particle size of the tested sintered compacts and directly proportional to the W content. Vickers microhardness, attenuation properties and microstructural characterization were carried out on the sintered samples. The attenuation test was conducted using gamma spectrometer with Genie 200 software. The samples of ball milled powder and of the highest volume fraction of W showed the highest hardness and attenuation values.

Effective gamma-ray attenuation coefficients for radioactive ores

1976 ◽  
Vol 40 (2) ◽  
pp. 206-207
Author(s):  
G. F. Novikov ◽  
A. Ya. Sinitsyn ◽  
Yu. O. Kozynda
Keyword(s):  
Gamma Ray ◽  
Attenuation Coefficients ◽  
Gamma Ray Attenuation
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