FAST NEUTRON SPECTRUM OF THE AFRRI TRIGA REACTOR.
GENERAL DYNAMICS CORP SAN DIEGO CALIF GENERAL ATOMIC DIV
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The angular flux spectrum was measured in a 43 cm sphere filled with the mixture ZrH1.9O0.3Fe0.1A10.05B0.01 representing the approximate homogenized TRIGA reactor core composition without uranium, and with boron added for thermal neutron absorption. The sphere was reflected with 5.08 cm of water. A 7.6 cm diameter depleted uranium target embedded at the center, excited by a 20 nsec pulsed electron beam for a Linac, was the neutron source for the time-of-flight experiment 50 meter flight distance. Detectors were a 5 by 5 cm liquid scintillator for spectra from 0.4-14 MeV, and a boron capture gamma ray detector for 0.1-0.5 MeV. Measurements were made at 7.6 cm penetration 0 and 51 degrees to the radius vector, at the core-reflector interface, and at the surface of the reflector 0 and 46 degrees. Calculations of the spectrum in the experimental assembly were made with the GAPLSN S sub n code in S8, with 20-group P3 cross sections from the GAM-II code. Comparisons between calculations and experiment were made to decide on the angular mesh, order of anisotropic scattering approximation, energy grouping, and cross sections for a similar calculation of the critical TRIGA reactor spectrum. Results of the calculated cylindrical geometry, P3, S8 angular flux spectrum and total leakage spectrum at the surface of the reflector are tabulated. Author
- Nuclear Fission Reactors (Non-Power)
- Fission Reactor Physics
- Nuclear Physics and Elementary Particle Physics