scholarly journals Determination of the response function of the NaI detector for g-quanta with an energy of 4.43 MeV, formed during inelastic scattering of neutrons with an energy of 14.1 MeV on carbon nuclei

2020 ◽  
Vol 4 (4) ◽  
pp. 281-290
Author(s):  
S.B. Dabylova ◽  
Yu.N. Kopach ◽  
S.K. Sakhiyev ◽  
D.N. Grozdanov ◽  
N.A. Fedorov

The work is devoted to determining the response function of the detector NaI(Tl) for g -quanta with energy of 4.43 MeV, formed during inelastic scattering of neutrons with energy of 14.1 MeV on the nuclei 12C. In gamma spectrometry, output pulses are recorded, the amplitudes of which are proportional to the energy lost in the detection medium by incident photons. One of the main tasks of radiation detection is to restore radiation characteristics from signals measured at the outputs of detectors. For this, it is necessary to know, first of all, the general characteristics of detectors as converters of radiation into signals. The main characteristic of the detector is its response function, which can be defined as the probability that a particle with given properties generates a certain signal in the detector that will be registered by the device. The article presents the results of modeling the response function of a scintillation detector based on a NaI(Tl) crystal for gamma radiation from inelastic fast neutron scattering in order to study the mechanism of its formation.

Author(s):  
Boris G. Titov ◽  
◽  
Vladimir M. Gruznov ◽  

A new nuclear–physical method and scheme of a device for logging gas and oil wells with the simultaneous determination of the density and porosity of the rocks behind the well are substantiated. Density and porosity are determined by one device. The pulsed neutron irradiation of the medium behind the well was used. Density and porosity are determined by gamma radiation from inelastic scattering and radiation capture of rock–forming elements by two spaced apart gamma spectrometric detectors.


2010 ◽  
Vol 6 (2) ◽  
pp. 170-174
Author(s):  
Sunardi Sunardi ◽  
Muryono Muryono

Determination of limit detection of the elements N, P, K, Si, Al, Fe, Cu, Cd, with fast neutron activation using neutron generator has been done.  Samples prepared from SRM 2704, N, P, K elements from MERCK, Cu, Cd, Al from activation foil made in San Carlos, weighted and packed for certain weight then iradiated during 30 minutes with 14 MeV fast neutron using the neutron generator and then counted with gamma spectrometry (accuspec).  At this research condition of neutron generator was set at current 1 mA that produced neutron flux about 5,47.107 n/cm2.s and  experimental result shown that the limit detection for the elements N, P, K, Si, Al, Fe, Cu, Cd are  2,44 ppm, 1,88 ppm, 2,15 ppm, 1,44 ppm, 1,26 ppm, 1,35 ppm, 1,05 ppm, 2,99 ppm, respectively.  The data  indicate that the limit detection or sensitivity of appliance of neutron generator to analyze the element is very good, which is feasible to get accreditation AANC laboratory using neutron generator.   Keywords: limit detection, AANC, neutron generator


Author(s):  
S. Golladay

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.


Author(s):  
T. Y. Tan ◽  
W. K. Tice

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.


Author(s):  
Y. Kikuchi ◽  
N. Hashikawa ◽  
F. Uesugi ◽  
E. Wakai ◽  
K. Watanabe ◽  
...  

In order to measure the concentration of arsenic atoms in nanometer regions of arsenic doped silicon, the HOLZ analysis is carried out underthe exact [011] zone axis observation. In previous papers, it is revealed that the position of two bright lines in the outer SOLZ structures on the[011] zone axis is little influenced by the crystal thickness and the background intensity caused by inelastic scattering electrons, but is sensitive to the concentration of As atoms substitutbnal for Siatomic site.As the result, it becomes possible to determine the concentration of electrically activated As atoms in silicon within an observed area by means of the simple fitting between experimental result and dynamical simulatioan. In the present work, in order to investigate the distribution of electrically activated As in silicon, the outer HOLZ analysis is applied using a nanometer sized probe of TEM equipped with a FEG.Czodiralsld-gown<100>orientated p-type Si wafers with a resistivity of 10 Ώ cm are used for the experiments.TheAs+ implantation is performed at a dose of 5.0X1015cm-2at 25keV.


Fuel ◽  
1975 ◽  
Vol 54 (1) ◽  
pp. 70-71 ◽  
Author(s):  
Charles E. Hamrin ◽  
Peter S. Maa ◽  
Lindgren L. Chyi ◽  
William D. Ehmann

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