Nuclear Data and the Effect of Gadolinium in the Moderator

2012 ◽  
Vol 1 (1) ◽  
pp. 21-25 ◽  
Author(s):  
J.C. Chow ◽  
F.P. Adams ◽  
D. Roubstov ◽  
R.D. Singh ◽  
M.B. Zeller
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Neutron Transport ◽  
Nuclear Data ◽  
Calibration Data ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Reactivity Effect ◽  
Section Data

Recent cross-section measurements on gadolinium have raised concerns over the accuracy of moderator poison reactivity coefficient calculations. Measurements have been made at the ZED-2 (Zero Energy Deuterium) critical facility, Chalk River Laboratories, AECL, to study the reactivity effect of gadolinium in the moderator. Since the neutron capture cross-section of boron is well known, measurements were also made with boron to provide calibration data for measurements with gadolinium. The measurements have been used to quantify the bias of the reactivity effect in full-core simulations of ZED-2 using MCNP, a neutron transport code used extensively for simulations of nuclear systems, along with the ENDF/B-VII.0 cross-section data. The results showed a bias of -0.41 ± 0.07 mk/ ppm, or -2.1% ± 0.3%, given a reactivity worth of -20.1 mk/ppm for gadolinium. Additional simulations also show that the gadolinium neutron capture cross-section has been over-corrected, relative to previous evaluations, in a beta version of ENDF/B VII.1, which incorporates the Leinweber data.

scholarly journals Neutron capture cross section of 185Re leading to ground and isomer states of 186Re in the keV-neutron energy region

2018 ◽  
Vol 178 ◽  
pp. 03005
Author(s):  
T. Katabuchi ◽  
K. Takebe ◽  
S. Umezawa ◽  
R. Fujioka ◽  
T. Saito ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Energy Region ◽  
Capture Cross Section ◽  
Production Cross ◽  
Pulse Height ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Section Data ◽  
The Difference

The neutron capture cross section of 185Re was measured in the astrophysically important energy region. Measurements were made using a neutron beam from a 7Li(p,n)7Be neutron source with energies ranging from 3 to 90 keV. Two different experimental techniques, time-of-flight (TOF) and activation methods, were employed. In the TOF experiments, the total neutron capture cross section of 185Re was determined by the pulse-height weighting technique. In the activation method, the partial capture cross section leading to the ground state of 186Re was measured by detecting decay γ-rays from neutron activated samples. The present cross section values were compared with evaluated cross section data and previous measurements. The difference between the TOF and activation results was smaller than experimental uncertainties. This suggests that the production cross section of isomer states of 186Re is very small.

scholarly journals A review of nuclear data for the k₀-based neutron activation analysis

2019 ◽  
Vol 9 (1) ◽  
pp. 28-33
Author(s):  
Manh Dung Ho ◽  
Lathdavong Phonesavanh
Keyword(s):  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
Neutron Activation ◽  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Nuclear Data ◽  
Thermal Neutron Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section

Nuclear data for the k0-based neutron activation analysis (k0-NAA) including: k0-factors – combination of nuclear constants (atomic mass, isotopic abundance, gamma-ray yield and thermal neutron capture cross section); Q0 – the ratio of the resonance integral to thermal neutron capture cross section; and Er – effective resonance energy, along with the related nuclear data are presented and evaluated in the presentation. Accuracy and capability of k0-NAA depends considerably on the reliability of the above mentioned nuclear data. In general, the evaluation of nuclear data is essential and necessary in the field of nuclear science and technology, and this work is conducted by the nuclear data centers on the world as well as the research institutions where the nuclear data are usedfor R&D. Therefore, the evaluation of the nuclear data used in k0-NAA should also be performed so that some of data may no longer be appropriate should be redetermined. The evaluation of nuclear data in k0-NAA would contribute to the improvement of accuracy and reliability of the method, moreover, it would also contribute to the establishment a nuclear database in Vietnam in the future.

scholarly journals Measurement of the neutron capture cross-section of 237Np using ANNRI at MLF/J-PARC

2020 ◽  
Vol 239 ◽  
pp. 01017
Author(s):  
Gerard Rovira ◽  
Tatsuya Katabuchi ◽  
Kenichi Tosaka ◽  
Shota Matsuura ◽  
Kazushi Terada ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Pulse Height ◽  
Measurement Instrument ◽  
Region Of Interest ◽  
Proton Accelerator ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Section Data

The neutron capture-cross section of 237Np was measured using the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) with special emphasis in the region of interest for the core design of Accelerator-Driven Systems (ADS), from 0.5 to 500 keV. A neutron time-of-flight method was employed using the NaI(Tl) spectrometer in the ANNRI beamline at the Japanese Proton Accelerator Research Complex (J-PARC) together with the pulse-height weighting technique. The cross-section was determined by normalizing the results to JENDL-4.0 cross-section data at the first resonance of 237Np. In the 0.5 to 500 keV range, the present preliminary results present better agreement with previous experiments of Weston et al [3]. Experimental data from Esch et al [6] is about 15% lower than the present results. In comparision with evaluated data, ENDF/B-VIII.0 offers better agreement from 0.5 to 10 keV than with JENDL-4.0. From 0.5 to 10 keV JENDL-4.0 underestimates the present results by 10-15%. Nontheless, over 10 keV energy JENDL-4.0 shows good agreement up to 500 keV. The present preliminary cross-section has uncertainties of about 5% from 0.5 to 35 keV, a value lower than the uncertainties present in JENDL-4.0 of 6-10%. However, over 35 keV the total uncertainties steadily increase and amount to 10% at 500 keV.

Measurements of the neutron capture cross section of 243Am around 23.5 keV

2021 ◽  
pp. 1-6
Author(s):  
Yu Kodama ◽  
Tatsuya Katabuchi ◽  
Gerard Rovira ◽  
Atsushi Kimura ◽  
Shoji Nakamura ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Capture Cross ◽  
Neutron Capture Cross Section

THERMAL NEUTRON CAPTURE CROSS-SECTION OF Na23 AND Mn55

1953 ◽  
Vol 31 (3) ◽  
pp. 204-206 ◽  
Author(s):  
Rosalie M. Bartholomew ◽  
R. C. Hawkings ◽  
W. F. Merritt ◽  
L. Yaffe
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Capture ◽  
Half Life ◽  
Capture Cross Section ◽  
Thermal Neutron Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Capture Cross Sections

The thermal neutron capture cross sections of Na23 and Mn55 have been determined using the activation method. The values are 0.53 ± 0.03 and 12.7 ± 0.3 barns respectively with respect to σAul97 = 93 barns. These agree well with recent pile oscillator results. The half-life for Mn56 is found to be 2.576 ± 0.002 hr.

scholarly journals The 236U neutron capture cross-section measured at the n_TOF CERN facility

2017 ◽  
Vol 146 ◽  
pp. 11054
Author(s):  
M. Mastromarco ◽  
M. Barbagallo ◽  
M.J. Vermeulen ◽  
N. Colonna ◽  
S. Altstadt ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Capture Cross ◽  
Neutron Capture Cross Section
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