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Thorium-uranium fission radiographyResults are described for studies designed to develop routine methods for in-situ measurement of the abundance of Th and U on a microscale in heterogeneous samples, especially rocks, using the secondary high-energy neutron flux developed when the 650 MeV proton beam of an accelerator is stopped in a 42 x 42 cm diam Cu cylinder. Irradiations were performed at three different locations in a rabbit tube in the beam stop area, and thick metal foils of Bi, Th, and natural U as well as polished silicate glasses of known U and Th contents were used as targets and were placed in contact with mica which served as a fission track detector. In many cases both bare and Cd-covered detectors were exposed. The exposed mica samples were etched in 48% HF and the fission tracks counted by conventional transmitted light microscopy. Relative fission cross sections are examined, along with absolute Th track production rates, interaction tracks, and a comparison of measured and calculated fission rates. The practicality of fast neutron radiography revealed by experiments to data is discussed primarily for Th/U measurements, and mixtures of other fissionable nuclei are briefly considered.
Document ID
Document Type
Reprint (Version printed in journal)
Haines, E. L.
(California Inst. of Tech. Pasadena, CA, United States)
Weiss, J. R.
(California Institute of Technology, Jet Propulsion Laboratory, Pasadena Calif., United States)
Burnett, D. S.
(California Institute of Technology Pasadena, Calif., United States)
Woolum, D. S.
(California Institute of Technology, Pasadena; California State University Fullerton, Calif., United States)
Date Acquired
August 9, 2013
Publication Date
January 1, 1976
Publication Information
Publication: Nuclear Instruments and Methods
Volume: 135
Subject Category
Instrumentation And Photography
Funding Number(s)
Distribution Limits
No Preview Available