Effect of new cross section evaluations on neutron spectrum determination

1992 ◽  
Vol 39 (6) ◽  
pp. 2078-2085 ◽  
Author(s):  
P.J. Griffin ◽  
J.G. Kelly ◽  
T.F. Luera ◽  
J. VanDenburg
1976 ◽  
Vol 54 (7) ◽  
pp. 757-765 ◽  
Author(s):  
D. C. Santry ◽  
J. P. Butler

Excitation curves for the reactions 115In(n,n′) 115Inm, 113In(n,n′)113Inm, and 115In(n,2n)114Inm have been measured by the activation method. The neutron flux at energies below 5.1 MeV was determined with a calibrated neutron long counter while at higher energies, measurements were made relative to the known cross section for the 32S(n,p) reaction. Effective cross sections for a 235U fission-neutron spectrum calculated from our measured excitation curves are 173 ± 9 mb for 115In(n,n′)115Inm, 123 ± 24 mb for 113In(n,n′)113Inm, and 0.64 ± 0.06 mb for 115In(n,2n)114Inm.


1997 ◽  
Vol 78 (s1) ◽  
Author(s):  
P. M. Suárez ◽  
M.A. Arribére ◽  
A.J. Kestelman ◽  
I.M. Cohen

2020 ◽  
Vol 239 ◽  
pp. 18005
Author(s):  
Bohumil Jansky ◽  
Jiri Rejchrt ◽  
Evzen Novak ◽  
Anatoly Blokhin

The leakage neutron spectra measurements have been done on benchmark spherical assemblies with Cf-252 source in center of 1) heavy water sphere with diameter of 30 cm (with Cd cover) and of 2) iron spheres with diameter of 100 cm and 50 cm. It has been stated for years that transport calculations by iron overestimate measured spectra in energy region around 300 keV by about 20-40 % (calculation to measurement ratio C/E = 1.2-1.4). The influence of an artificial changes in cross-section XS-Fe-56 (n,elastic)designed by IAEA, Nuclear Data Section, has been studied on the iron spheres. Influence of those XS-corrections to calculated neutron spectrum is presented.


2021 ◽  
Vol 247 ◽  
pp. 09013
Author(s):  
Tadafumi Sano ◽  
Jun-ichi Hori ◽  
Jeaong Lee ◽  
Yoshiyuki Takahashi ◽  
Kazuki Takahashi ◽  
...  

In order to perform integral evaluation of 232Th capture cross section, a series of critical experiments for thorium-loaded and solid-moderated cores in KUCA had been carried out. In these experimental cores, H/235U nuclide ratio ranged about from 150 to 315, and 232Th/235U nuclide ratio ranged about from 13 to 19. In this study, a new critical experiment with Th loaded core in KUCA, which had about 70 of the H/235U ratio and 12.7 of 232Th/235U ratio, was carried out. As results, the excess reactivity was 0.086 ± 0.003 (% dk/k) and the keff was 1.0009 ± 0.0003, where the effective delayed neutron fraction was 7.656E-3. The keff was also calculated by MVP3.0 with different nuclear libraries. The respective calculations with JENDL-4.0, JENDL-3.3 and ENDF/B-VII.0 lead to 1.0056 ± 0.0086 (%), 1.0048 ± 0.0085 (%) and 1.0056 ± 0.0086 (%).On the other hand, the further MVP3.0 calculations, where only the 232Th cross sections were taken from JENDL-4.0, JENDL-3.3 or ENDF/B-VII.0 but all other nuclides were done from JENDL-4.0, were carried out to examine an impact of the difference of 232Th cross section among these nuclear libraries to the keff. The keff calculated with respective 232Th cross sections from JENDL-3.3 and ENDF/B-VII.0 was 1.0038 ± 0.0086 (%) and 1.0040 ± 0.0086 (%).


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