Application of Boron Filters for Neutron Spectrum Determination Purposes in Various Neutron Environments

摘要

Foil irradiation experiments were performed at the graphite reflector of LFR (ECN, Petten) and at the water reflector of WWR-SM (CRIP, Budapest). In the experiments the effect of boron covers for the activation and fission detector response regions were investigated. The fluence rate perturbation effects introduced in the graphite or water environment by the applied B/sub 4/C-box were determined by means of transport calculations. Spectrum adjustment calculations were performed by the SAND-II and STAY'SL codes. The results showed that the applied B/sub 4/C cover shifted the response regions of the resonance reactions from the thermal region to the 0.1 keV - 1.0 MeV energy interval. If boron-covered reactions are included in a least squares spectrum adjustment procedure, the uncertainty of the solution spectrum is also reduced significantly in this energy region. 17 refs.; 6 figs.; 3 tables. (Atomindex citation 18:100770)