Gamma-ray Spectral Analysis of a Solution of Mixed Fission Products

Author(s):  
Moses Attrep ◽  
Bernd Kahn
2019 ◽  
Vol 85 (2) ◽  
pp. 17-22
Author(s):  
M. I. Khamdeev ◽  
E. A. Erin

Physical parameters of electric arc plasma as well as their time dependences are calculated when analyzing phosphate precipitates of the fission products of irradiated nuclear fuel. Phosphate concentrates of the fission products are known for their complex chemical composition and high thermal and chemical stability. Hence, direct atomic emission spectral analysis of phosphate powders without transferring them into solutions is advisable. Different conditions of sample preparation and synthesis of the reference materials determine the different chemical forms of the elements to be determined. This, in turn, affects the kinetics of their evaporation in the electrode crate and excitation processes in the plasma. The known mechanisms of those processes cannot always be transferred to specific conditions of the given method of analysis thus entailing the necessity of studying the effect of the samples chemical composition on the results of determination, proper choice of spectroscopic carriers, detailed study of spectra excitation processes in spectral analysis, and analysis of the physical parameters of the electric arc plasma. We used the lines Zn I 307.206 nm and Zn I 307.589 nm to measure the effective temperature of the central hot sections of the arc in a range of4500 - 6500 K. NaCl, BaCl2 and NaCl + T1C1 were studied to reduce the effect of the sample elemental composition on excitation conditions of the spectra and their stabilization as a spectroscopic carrier. In control experiments we used carrier-free samples. The coincidence of the values of the plasma physical parameters within the measurement error not exceeding 20%, as well as the identity of the nature of the kinetic curves for samples of phosphate precipitates and synthetic reference materials prove their correctness. The result of the study substantiate correctness of the direct atomic-emission spectral procedure in analysis of phosphate concentrates of fission when using synthetic reference materials.


2012 ◽  
Vol 8 (S291) ◽  
pp. 160-160
Author(s):  
Silvia Zane

AbstractSoft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are peculiar X-ray sources which are believed to be magnetars: ultra-magnetized neutron stars which emission is dominated by surface fields (often in excess of 1E14 G, i.e. well above the QED threshold).Spectral analysis is an important tool in magnetar astrophysics since it can provide key information on the emission mechanisms. The first attempts at modelling the persistent (i.e. outside bursts) soft X-ray (¡10 keV) spectra of AXPs proved that a model consisting of a blackbody (kT 0.3-0.6 keV) plus a power-law (photon index 2-4) could successfully reproduce the observed emission. Moreover, INTEGRAL observations have shown that, while in quiescence, magnetars emit substantial persistent radiation also at higher energies, up to a few hundreds of keV. However, a convincing physical interpretation of the various spectral components is still missing.In this talk I will focus on the interpretation of magnetar spectral properties during quiescence. I will summarise the present status of the art and the currents attempts to model the broadband persistent emission of magnetars (from IR to hard Xrays) within a self consistent, physical scenario.


Nukleonika ◽  
2018 ◽  
Vol 63 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Stanisław Kilim ◽  
Elżbieta Strugalska-Gola ◽  
Marcin Szuta ◽  
Marcin Bielewicz ◽  
Sergej I. Tyutyunnikov ◽  
...  

Abstract Neptunium-237 samples were irradiated in a spallation neutron field produced in accelerator-driven system (ADS) setup QUINTA. Five experiments were carried out on the accelerators at the JINR in Dubna - one in carbon (C6+), three in deuteron, and one in a proton beam. The energy in carbon was 24 GeV, in deuteron 2, 4 and 8 GeV, respectively, and 660 MeV in the proton beam. The incineration study method was based on gamma-ray spectrometry. During the analysis of the spectra several fission products and one actinide were identified. Fission product activities yielded the number of fissions. The actinide (Np-238), a result of neutron capture by Np-237, yielded the number of captures. The main goal of this work was to find out if and how the incineration rate depended on parameters of the accelerator beam.


1966 ◽  
Vol 3 (5) ◽  
pp. 200-207 ◽  
Author(s):  
Sei-ichi TAKAYANAGI ◽  
Noboru OI ◽  
Tetsuji KOBAYASHI ◽  
Tohru SUGITA

2019 ◽  
Vol 887 (1) ◽  
pp. 13 ◽  
Author(s):  
F. Fana Dirirsa ◽  
S. Razzaque ◽  
F. Piron ◽  
M. Arimoto ◽  
M. Axelsson ◽  
...  

10.2118/748-g ◽  
1957 ◽  
Vol 210 (01) ◽  
pp. 89-92 ◽  
Author(s):  
N.L. Muench ◽  
J.S. Osoba
Keyword(s):  

2018 ◽  
Vol 854 (2) ◽  
pp. 99 ◽  
Author(s):  
J. Wu ◽  
C. J. Clark ◽  
H. J. Pletsch ◽  
L. Guillemot ◽  
T. J. Johnson ◽  
...  

1958 ◽  
Vol 2 ◽  
pp. 107-115
Author(s):  
Vincent G. Scotti ◽  
James I. Mueller ◽  
John J. Little

AbstractWith the advent of nuclear engineering, x-ray diffraction has become an important analytical tool in the study of radiation damage due to neutron and gamma-ray irradiation. The materials under study in this work have rdioactive levels up to 40 R/hr. at 17 centimeters combined β and γ. The activity of the various samples under study may be due to (n, γ) reactions or fission products or both.Data are presented to illustrate the use of sample shielding, detector shielding pulse height discrimination and the combination of all three aids in an effort to attain the most favorable peak to background ratio.


1965 ◽  
Vol 48 (1) ◽  
pp. 1-5
Author(s):  
Harry M Yakabe ◽  
Hiram Neilson

Abstract In the surveillance of bulk food produce by gamma ray spectroscopy for fission products, the activities of the commonly observed radionuclides are frequently in the magnitude of background inherent to the detection system. The problems of determining whether the sample is in fact contaminated, the lower limits of detecting the radionuclides, and the effect of compton smear on the lower limits are discussed. The discussions are based on the modified spectrum stripping method for quantitative analysis of gamma ray spectrum for the following radioisotopes: Cs-137, Zr-95/Nb-95, and K-40. A family of curves are shown for rapid determination of the minimum detectable true activity (AII) of Cs-137.


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