NEUTRON CROSS SECTION EVALUATIONS FOR ACTINIDES AT INTERMEDIATE ENERGIES: Pu–239

Authors & Affiliations

Ignatyuk A.V.1, Lunev V.P.1, Shubin Yu.N.1, Gai E.V.1, Titarenko N.N.1, Gudowski W.2

1State Scientific Centre - A.I. Leipunsky Institute for Physics and Power Engineering, Obninsk, Russia
2Royal Institute of Technology, Stockholm, Sweden

Abstract

Investigations aimed at the development of neutron cross section evaluations for actinides performed at IPPE in collaboration with Royal Institute of Technology, Stockholm at intermediate energies in the range of 0–200 MeV are briefly described on the example of 239Pu. The coupled-channels optical model is used to calculate the neutron total, elastic and reaction cross sections and the elastic scattering angular distributions. Evaluations of the neutron and charged particle emission cross sections and of the fission cross sections are obtained on the basis of the statistical description that includes direct, preequilibrium and equilibrium mechanisms of nuclear reactions. The Kalbach parametrization of angular distributions is used to describe the double-differential cross sections of emitted neutrons and charged particles in ENDF/B-VI format. These investigations resulted in creation of complete neutron and proton data files for 238U and 232Th and neutron data file for 239Pu up to 150 MeV. These files were processed with NJOY.

Keywords
actinides, neutron cross section, Pu-239, coupled-channels optical model , eaction cross sections, angular distributions, elastic scattering, direct, preequilibrium and equilibrium mechanisms of nuclear reactions, Kalbach parametrization

Article Text (PDF, английский)

References

UDC 539.17

Problems of Atomic Science and Technology. Series: Nuclear Constants", issue 2, 2001