JENDL-3.2 Covariance File

• Published in: Journal of nuclear science and technology Vol. 39; no. sup2; pp. 40 - 43
• Main Authors: Shibata, Keiichi, Hasegawa, Akira, Iwamoto, Osamu, Chiba, Satoshi, Sugimoto, Masayoshi, Odano, Naoteru, Kawano, Toshihiko, Nakajima, Yutaka, Murata, Toru, Matsunobu, Hiroyuki, Oh, Youl Soo, Yokoyama, Kenji, Sugino, Kazuteru, Ishikawa, Makoto, Kosako, Kazuaki, Yamano, Naoki, Kanda, Yukinori
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.08.2002
• Subjects: covariance; cross section; fission neutron spectrum; JENDL-3.2; Legendre coefficient; resonance parameter
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/00223131.2002.10875034

Covariances of neutron nuclear data have been estimated for 16 nuclides contained in JENDL-3.2. The physical quantities for which covariances are deduced are cross sections, resolved and unresolved resonance parameters, the first order Legendre-polynomial coefficients for the angular distribution of elastically scattered neutrons, and fission neutron spectra. As for 233,235,238 U and 239,241 Pu, covariances were obtained also for the average number of neutrons emitted in fission. Least-squares methods were applied to obtain the covariances of those cross sections which were based on experimental data. A simultaneous evaluation method yielded uncertainties in the fission cross sections of 235 U, 238 U, 239 Pu, 240 Pu and 241 Pu. Covariances of nuclear model calculations were determined from uncertainties in model parameters. The covariance file thus obtained is processed by a system which has been developed, and used for the adjustment of group cross sections.