International Conference on Nuclear Data for Science and Technology 2007
DOI: 10.1051/ndata:07139

An international neutron cross section standards evaluation

Allan Carlson¹, Sergey Badikov², Chen Zhenpeng³, Evgenij Gai², Gerald Hale⁴, Franz-Josef Hambsch⁵, Hartmut Hofmann⁶, Toshihiko Kawano⁴, Nancy Larson⁷, Soo-Youl Oh⁸, Vladimir Pronyaev², Donald Smith⁹, Siegfried Tagesen¹⁰ and Herbert Vonach<sup>10

1</sup>  National Institute of Standards & Technology, 100 Bureau Dr. MS 8463, Gaithersburg, MD 20899-8463, USA
²  Institute of Physics & Power Engineering, Bondarenko sq. 1, 249033 Obninsk, Kaluga Region, Russia
³  Tsinghua University, Beijing 100084, China
⁴  Los Alamos National Laboratory, T-2, MS B-243, Los Alamos, NM 87545, USA
⁵  Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium
⁶  Erlangen-Nuernberg University, Staudtstrasse 7, 91058 Erlangen, Germany
⁷  Oak Ridge National Laboratory, Bldg. 5700, MS 6171, P.O. Box 2008, Oak Ridge, TN 37831-6171, USA
⁸  Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon 305-600, Republic of Korea
⁹  Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, USA
¹⁰  Vienna University, Waehringerstrasse 17, 1090 Vienna, Austria

carlson@nist.gov

Published online: 21 May 2008

Abstract
A new evaluation of the neutron cross section standards was recently completed. The results of this work became the standards for the new ENDF/B-VII library. This evaluation was performed to include new experiments on the standards that have been made since the ENDF/B-VI standards evaluation was completed and to improve the evaluation process. The evaluations include the H(n,n), ⁶Li(n,t), ¹⁰B(n,α), ¹⁰B(n,α₁γ), ¹⁹⁷Au(n,γ), ²³⁵U(n,f), and ²³⁸U(n,f) standard reactions. Evaluations were not done for the ³He(n,p) and C(n,n) standards which were carried over from ENDF/B-VI. The need for standards above 20 MeV led to the extension of the ²³⁵U(n,f) and ²³⁸U(n,f) cross sections to 200 MeV. In addition evaluations were produced for the non-standard ²³⁸U(n,γ) and ²³⁹Pu(n,f) reactions. Results of this work and comparisons with previous evaluations are presented.

© CEA 2008