Measurements and calculations of neutron spectra in infinite media

Measurements and calculations of the spatial dependence of neutron spectra in simulated infinite 0 p.u. sandstone, limestone and dolomite media will be shown. A 14 MeV neutron generator source and an organic scintillator detector, which is sensitive to MeV neutrons, were used in the measurements. Basically, 1-ft cubes were offset to form 3-in. square measuring ports to allow detection at 1,2 and 3 feet from the source. Mathematical modeling was used to identify the characteristic features of the neutron spectra. It is intended that such experimental to calculational comparisons will test the high energy cross sections used in the modeling calculations. (author)