ISSN: 1546-962X
Page Count: 9

An International Evaluation of the Neutron Cross Section Standards
Carlson, AD
Physicist, National Institute of Standards and Technology, MD

Badikov, SA
Physicist, Institute of Physics & Power Engineering,

Chen, Z
Physicist, Tsinghua University,

Gai, EV
Physicist, Los Alamos National Laboratory, NM

Hale, GM
Physicist, Institute for Reference Materials and Measurements,

Hambsch, F-J
Physicist, Erlangen-Nürnberg University,

Hofmann, HM
Physicist, Los Alamos National Laboratory, NM

Kawano, T
Physicist, Oak Ridge National Laboratory, TN

Larson, NM
Physicist, Korean Atomic Energy Research Institute,

Oh, S-Y
Physicist, Institute of Physics & Power Engineering,

Pronyaev, VG
Physicist, Argonne National Laboratory, IL

Smith, DL
Physicist, Vienna University,

Tagesen, S

Vonach, H

Abstract

Work is reported here on the process and present results of an international evaluation of the neutron cross section standards. The evaluations include the H(n,n), ³He(n,p), ⁶Li(n,t), ¹⁰B(n,α), ¹⁰B(n,α¹γ), ¹⁹⁷Au(n,γ), ²³⁵U(n,f), and ²³⁸U(n,f) standard reactions as well as the ²³⁸U(n,γ) and ²³⁹Pu(n,f) reactions. This evaluation was performed to include new experiments on the standards that have been made since the ENDF/B-VI evaluation was completed and to improve the evaluation process. Evaluations have been completed for the ⁶Li(n,t), ¹⁹⁷Au(n,γ) and ²³⁸U(n,γ) cross sections. Also below 20 MeV the H(n,n), ²³⁵U(n,f), ²³⁸U(n,f) and ²³⁹Pu(n,f) cross sections are completed. Many of the cross sections being evaluated are used in neutron dosimetry for fluence determination. The general trend observed for the evaluations is an increase in the cross sections for most of the reactions from fractions of a percent to several percent compared with the ENDF/B-VI results.

Keywords:
neutron cross section standards, fission standards, capture standards, R-matrix, evaluation

Paper ID: JAI13422
DOI: 10.1520/JAI13422
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