MEASUREMENT OF NEUTRON SPECTRUM, AGE, AND DIFFUSION LENGTH IN CONCRETE,
Abstract
Activation foil detectors were used to measure the fast-neutron spectrum, slowing-down age, and thermal-diffusion length in concrete. The neutron source was a uranium fission plate placed in the graphite thermal column of the University of Virginia Reactor. Experimental concrete slabs were placed in the concrete biological shield of the reactor so that the medium was essentially infinite in the lateral direction. Indium, magnesium, and aluminum threshold foils were used to map the fast flux; indium, gold, tungsten, and manganese resonance foils to measure the neutron age; and indium and gold foils to measure the thermal neutron distribution. The fast spectrum retains essentially the fission shape with a slight dip in the 3- to 5-MeV range. The measured ages are essentially the same, l49 cm to the indium, gold, and tungsten resonances and 126 sq cm to the manganese resonances. The thermal diffusion length was measured as 6.0 plus or minus 0.5 cm. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1967
- Accession Number
- AD0646630
Entities
People
- Gene M. Lim
- T. G. Williamson
- W. Reed Johnson
Organizations
- University of Virginia