Measurement of the selected spectral averaged cross sections in a radial channel of the VR-1 reactor.

Abstract

The spectral averaged cross section is an important quantity used in a validation of nuclear cross section. When the cross sections are averaged over the neutron standard field (252Cf(s,f) or 235U(n,f) neutron spectrum), they can be used for tuning of evaluations. This kind of quantities is very useful because the data in integral measurements can be determined with a significantly smaller uncertainties than the standard differential data. The experiment was aimed at the spectral average cross sections measurement and was performed in a radial channel of VR-1 reactor (with fuel enrichment 19.75\u202fwt %). The results are in a good agreement within the uncertainties with a previous measurements in LR-0 reactor (with fuel enrichment 3.3\u202fwt %), thus it supports the hypothesis that even significant amount of 238U(n,f) neutrons in the LR-0 reactor spectrum does not have a significant influence. The derived spectral averaged cross sections are as follows: 0.1709\xa0±\xa00.0115\xa0mb for 89Y(n,2n), 10.738\xa0±\xa00.719\xa0mb for 46Ti(n,p), 17.896\xa0±\xa01.181\xa0mb for 47Ti(n,p), 0.294\xa0±\xa00.02\xa0mb for 48Ti(n,p), 72.994\xa0±\xa04.964\xa0mb for 54Fe(n,p), 0.528\xa0±\xa00.036\xa0mb for 63Cu(n,α), 0.444\xa0±\xa00.029\xa0mb for 93Nb(n,2n)92Nb* and 0.239\xa0±\xa00.016\xa0mb for 58Ni(n,x)57Co.