INTEGRAL TEST OF NEUTRON CROSS SECTIONS IN FUSION ENVIRONMENT
Department of Reactor Engineering, Japan Atomic Energy Research Institute
Tokai-mura, Naka-gun, Ibaraki-ken, 319-11, Japan
Integral experiments in fusion environment have been carried out in a frame of JAERI-U.S. collaborative program on fusion blanket neutronics. In the experiment, a test region for blanket of Li2O and the D-T source are enclosed by a Li2CO3 container in order to simulate well a fusion neutron field in the test regions with and without a beryllium multiplier in the front of it. The measured parameters are tritium production rates (TPRs) by 6Li and 7Li, neutron spectrum and various foil activation rates used in diagnoses of neutron field. The analysis of the experiments has been performed by using a Monte Carlo code MORSE-DD and 125 group set DDL/J3Pl. The analysis indicates that the underestimation of 7Li(n,n'α)t cross section in JENDL/3PR1 and the activation rate distributions with ENDF/B-IV are overestimated for Ni(n,p), Nb(n,2n) by 10 - 20 % and underestimated for Ni(n,2n) reactions by about 10 %. The newly measured cross sections, however, significantly decrease such discrepancies. A beryllium (n,2n) cross section seems to be reasonable.
KEYWORDS: integral test, activation cross section, fusion neutron, beryllium, lithium oxide