Pyrochemical neutron multiplicity counter design [electronic resource].
- Washington, D.C : United States. Dept. of Energy. Office of the Assistant Secretary for Defense Programs, 1990. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: (6 pages) : digital, PDF file
- Additional Creators:
- Los Alamos National Laboratory, United States. Department of Energy. Office of the Assistant Secretary for Defense Programs, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Pyrochemical process materials are difficult to measure using conventional neutron counting methods because of significant self- multiplication and variable (α,n) reaction rates. Multiplicity counters measure the first three moments of the neutron multiplicity distribution and thus make it possible to determine sample mass even when multiplication and (α,n) rate are unknown. A new multiplicity counter suitable for inplant measurement of pyrochemical process materials has been designed using Monte Carlo simulations. The goals were to produce a counter that has high neutron detection efficiency, low die-away time, a flat spatial efficiency profile, and is insensitive to the neutron energy spectrum. Monte Carlo calculations were performed for several prototype models consisting of four rings of 71-cm active length ³He tubes in a polyethylene body. The cadmium-lined sample well is 25 cm in diameter to accommodate a wide variety of inplant sample containers. The counter can be free-standing or in-line without mechanical modification. The calculations were performed to determine the above design criteria for several configurations of tube spacing, cadmium liners, and sample height. Calculations were also performed for distributed sample sources to understand the integrated effects of variable neutron spectra on the counter. 5 refs., 8 figs., 1 tab.
- Published through SciTech Connect., 01/01/1990., "la-ur-90-2255", " conf-9007106--47", "DE90015099", Institute of nuclear materials management conference, Los Angeles, CA (USA), 15-18 Jul 1990., and Langner, D.G.; Krick, M.S.; Ensslin, N.
- Funding Information:
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