High Resolution Neutron Spectrum Measurements in the Sandia Pulsed Reactor-II Facility

High resolution neutron spectrum measurements were made in the SPR-II glory hole, at 2.5, 15, 76 and 214 cm outside the core and in the beam port facility with proton-recoil gas proportional counters. The energy ranges were a few keV to 2.7 MeV depending upon the location and the resolution was 12% (ΔE/E, FWHM) over most of the energy range. The data showed that the exterior spectra were somewhat softer than that in the glory hole due to the influence of room return neutrons. Comparisons were made with fission couple measurements and Monte Carlo calculations at the glory hole and 2.5 cm positions. A composite spectrum from 12 keV to 8 MeV was formed from the proton-recoil and fission couple results. Silicon displacement damage was calculated for the various reactor positions using the different spectra.