Measurement and covariance analysis of 59Co(n, 2n)58Co reaction cross sections at the effective neutron energies of 11.98 and 15.75 MeV

2018 ◽  
Vol 106 (11) ◽  
pp. 877-884 ◽  
Author(s):  
Santhi Sheela Yerraguntla ◽  
Haladhara Naik ◽  
Manjunatha Karantha ◽  
Srinivasan Ganesan ◽  
Suryanarayana Venkata Saraswatula ◽  
...  
Keyword(s):  
Cross Sections ◽  
Present Experiment ◽  
Nuclear Data ◽  
Reaction Cross ◽  
Correlation Technique ◽  
Effective Neutron ◽  
Data Libraries ◽  
Nuclear Data Libraries ◽  
Evaluated Nuclear Data ◽  
Reaction Cross Sections

Abstract The 59Co(n, 2n)58Co reaction cross sections relative to the cross sections of the 115In(n, n′)115mIn reaction have been measured at the effective neutron energies of 11.98 and 15.75 MeV by using activation and off-line γ-ray spectrometric technique. Neutron beam used in the present experiment was generated from the 7Li(p, n)7Be reaction with the proton energies of 14 and 18 MeV at the 14UD BARC-TIFR Pelletron facility, Mumbai. We also present the covariance information by taking into account the sources of error and the correlations between the attributes influencing the measurements. The 59Co(n, 2n)58Co reaction cross sections from the present work are then compared with the values from different evaluated nuclear data libraries. The micro-correlation technique suggested by Smith was modified to generate the covariance matrix for the measurements of reaction cross sections as the efficiencies of detector for the sample and monitor are correlated.

scholarly journals Critical review of CIELO evaluations of n+ 235U, 238U using differential experiments

2018 ◽  
Vol 4 ◽  
pp. 27 ◽  
Author(s):  
Roberto Capote ◽  
Andrej Trkov
Keyword(s):  
Cross Sections ◽  
Critical Review ◽  
Nuclear Data ◽  
Reaction Cross ◽  
Reaction Models ◽  
Reaction Channels ◽  
Data Files ◽  
Integral Data ◽  
Evaluated Nuclear Data ◽  
Reaction Cross Sections

Key reactions have been selected to compare JEFF-3.3 (CIELO 2) and IAEA CIELO (CIELO 1) evaluated nuclear data files for neutron induced reactions on 235U and 238U targets. IAEA CIELO evaluation uses reaction models to construct the evaluation prior, but strongly relied on differential data including all reaction cross sections fitted within the IAEA Neutron Standards project. The JEFF-3.3 evaluation relied on a mix of differential and integral data with strong contribution from nuclear reaction modelling. Differences in evaluations are discussed; a better reproduction of differential data for the IAEA CIELO evaluation is shown for key reaction channels.

scholarly journals Evaluating nuclear data and their uncertainties

2018 ◽  
Vol 4 ◽  
pp. 29
Author(s):  
Patrick Talou
Keyword(s):  
Experimental Data ◽  
Uncertainty Quantification ◽  
Cross Sections ◽  
Coming Out ◽  
Nuclear Data ◽  
Covariance Matrices ◽  
Alternative Approaches ◽  
Data Libraries ◽  
Nuclear Data Libraries ◽  
Evaluated Nuclear Data

In the last decade or so, estimating uncertainties associated with nuclear data has become an almost mandatory step in any new nuclear data evaluation. The mathematics needed to infer such estimates look deceptively simple, masking the hidden complexities due to imprecise and contradictory experimental data and natural limitations of simplified physics models. Through examples of evaluated covariance matrices for the soon-to-be-released U.S. ENDF/B-VIII.0 library, e.g., cross sections, spectrum, multiplicity, this paper discusses some uncertainty quantification methodologies in use today, their strengths, their pitfalls, and alternative approaches that have proved to be highly successful in other fields. The important issue of how to interpret and use the covariance matrices coming out of the evaluated nuclear data libraries is discussed.

scholarly journals Generation of the 1H in H2O neutron thermal scattering law covariance matrix of the CAB model

2018 ◽  
Vol 4 ◽  
pp. 32
Author(s):  
Juan Pablo Scotta ◽  
Gilles Noguère ◽  
Jose Ignacio Marquez Damian
Keyword(s):  
Covariance Matrix ◽  
Nuclear Data ◽  
Water Model ◽  
Dynamic Simulations ◽  
Light Water ◽  
Thermal Scattering ◽  
Data Libraries ◽  
Hydrogen Bound ◽  
Nuclear Data Libraries ◽  
Evaluated Nuclear Data

The thermal scattering law (TSL) of 1H in H2O describes the interaction of the neutron with the hydrogen bound to light water. No recommended procedure exists for computing covariances of TSLs available in the international evaluated nuclear data libraries. This work presents an analytic methodology to produce such a covariance matrix-associated to the water model developed at the Atomic Center of Bariloche (Centro Atomico Bariloche, CAB, Argentina). This model is called as CAB model, it calculates the TSL of hydrogen bound to light water from molecular dynamic simulations. The performance of the obtained covariance matrix has been quantified on integral calculations at “cold” reactor conditions between 20 and 80∘ C. For UOX fuel, the uncertainty on the calculated reactivity ranges from ±71 to ±155 pcm. For MOX fuel, it ranges from ±110 to ±203 pcm.

scholarly journals CENDL-3.2: The new version of Chinese general purpose evaluated nuclear data library

2020 ◽  
Vol 239 ◽  
pp. 09001
Author(s):  
Zhigang Ge ◽  
Ruirui Xu ◽  
Haicheng Wu ◽  
Yue Zhang ◽  
Guochang Chen ◽  
...  
Keyword(s):  
Cross Sections ◽  
Nuclear Data ◽  
General Purpose ◽  
Reaction Cross ◽  
Main Reaction ◽  
Science And Engineering ◽  
Nuclear Data Library ◽  
Evaluation Techniques ◽  
Data Library ◽  
Evaluated Nuclear Data

A new version of Chinese Evaluated Nuclear Data Library, namely CENDL-3.2, has been completed under the joint efforts of CENDL working group. This library is constructed with the general purpose to provide high-quality nuclear data for the modern nuclear science and engineering. 272 nuclides from light to heavy are covered in CENDL-3.2 in total and the data for 134 nuclides are new or updated evaluations in energy region of 10-5 eV-20 MeV. The data of most of the key nuclides in nuclear application like U, Pu, Th, Fe et al. have been revised and improved, and various evaluation techniques have been developed to produce the nuclear data with good quality. Moreover, model dependent covariances data for main reaction cross sections are added for 70 fission product nuclides. To assess the accuracy of CENDL-3.2 in application, the data have been tested with the criticality and shielding benchmarks collected in ENDITS-1.0.

scholarly journals Theoretical calculation and evaluation of neutron inducedreactions on Pu isotopes

2020 ◽  
Vol 239 ◽  
pp. 03008
Author(s):  
Hairui Guo ◽  
Yinlu Han ◽  
Tao Ye ◽  
Weili Sun ◽  
Wendi Chen
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Nuclear Data ◽  
Reaction Cross ◽  
Driven Systems ◽  
Intranuclear Cascade ◽  
Pu Isotopes ◽  
Design Requirements ◽  
Accelerator Driven Systems ◽  
Reaction Cross Sections

The nuclear data on n+239,240,242,244Pu reactions for the incident energy up to 200 MeV are consistently calculated and evaluated in order to meet the design requirements of Generation-IV reactors and accelerator driven systems. The optical model, the distorted wave Born approximation theory, the Hauser-Feshbach theory, the fission model, the evaporation model, the exciton model and the intranuclear cascade model are used in the calculation, and new experimental data are taken into account. Our data are compared with experimental data and the evaluated data from JENDL-4/HE and TENDL. In addition, the variation tendency of reaction cross sections related to the target mass numbers is obtained, which is very important for the prediction of nuclear data on neutron-actinides reactions because the experimental data are lacking.

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