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U.S. Department of Energy
Office of Scientific and Technical Information

Portable nuclear moisture-density gauge with low activity nuclear sources

Patent ·
OSTI ID:6662586
This patent describes a method of measuring the density of a test material using a low activity gamma radiation source in the presence of a neutron radiation source, comprising: directing fast neutrons from a neutron radiation source into the test material, detecting neutrons which have been moderated and thermalized by neutron moderating elements present in the test material and generating a signal representative of the moisture content of the test material, directing gamma radiation from a gamma radiation source into the test material, detecting gamma radiation emitted from the gamma radiation source and which passes through the test material and generating an uncorrected signal which is representative of the density of the test material plus error due to extraneous background radiation, generating a correction signal which is a function of the moisture signal and which represents the amount of gamma radiation emitted from the test material resulting from the (n, UPSILON) neutron capture reaction due to the presence of neutron capture elements, such as hydrogen, in the test material, and applying the correction signal to the uncorrected density signal to obtain a corrected density signal which is unaffected by background gamma radiation caused by the presence of neutron capture elements in the test material.
Assignee:
Troxler Electronic Laboratories, Inc., Research Triangle Park, NC
Patent Number(s):
US 4766319
OSTI ID:
6662586
Country of Publication:
United States
Language:
English