Accession Number : AD0680949

Title :   FAST NEUTRON SPECTRUM AND DOSE RATE IN WATER AND IN ALUMINUM-WATER LAMINATIONS,

Corporate Author : VIRGINIA UNIV CHARLOTTESVILLE SCHOOL OF ENGINEERING AND APPLIED SCIENCE

Personal Author(s) : Coulbourn,G. I. ; Williamson,T. G.

Report Date : NOV 1968

Pagination or Media Count : 51

Abstract : The fast neutron spectrum was measured by seven threshold reaction detectors at various distances from a point fission neutron source in water and in two aluminum and water mixtures. The attenuation of the fast neutron dose rate and of the thermal neutron flux was also determined. The experimental results were compared with calculations made with the ANISN computer code. By use of experimentally determined counting efficiencies, absolute saturation activities of the threshold reaction products were determined. A method of neutron spectrum unfolding was devised which represented the fast neutron spectrum by a group of successive exponentials calculated from the saturation activities. The reported spectra generally agreed with the results predicted by the ANISN code. The fast neutron dose rate was measured directly with p-i-n silicon diode dosimeters and indirectly by applying flux-to-dose conversion factors to the measured fast neutron flux. Good agreement was obtained between these measurements and calculations. The saturation activities from the 32S(n,p) reaction were compared with the measured and calculated dose rates and an activity-to-dose-rate conversion factor was estimated. (Author)

Descriptors :   (*NEUTRON SPECTRUM, SHIELDING), (*FISSION NEUTRONS, *SHIELDING), WATER, ALUMINUM, NEUTRON FLUX, DOSE RATE, DOSIMETERS, COMPUTERS, DIODES, NEUTRON ACTIVATION, RADIOACTIVE ISOTOPES, STANDARDIZATION, LAMINATES

Subject Categories : Nuclear Radiation Shield, Protection & Safety
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE