Accession Number:

AD0673108

Title:

PLUTONIUM BERYLLIUM NEUTRON SOURCE AS A SECONDARY CALIBRATION STANDARD,

Descriptive Note:

Corporate Author:

BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD

Personal Author(s):

Report Date:

1968-06-01

Pagination or Media Count:

36.0

Abstract:

Plutonium-Beryllium Pu-Be neutron sources are calibrated with respect to total output, using a manganese-sulfate bath. When such sources are used as a point isotropic, secondary standard, inaccuracies occur due to the following reasons 1 The neutron output is not isotropic, 2 the neutron output increases with time due to the build-up of Americium-241, resulting from the impurity of Plutonium-241, 3 the output spectrum is continuous from approximately 0.5 MeV to 10 MeV, 4 gamma rays exceed the number of neutrons emitted from the source. This report 1 presents the angular distribution of the neutron output of an 80 gram 4.81 curie Plutonium-Beryllium neutron source, 2 shows that the increase in neutron output, due to the build-up of Americium-241 is 5.3 percent for a period of 43 months, 3 presents the neutron and gamma ray spectral distribution and intensity, 4 shows a neutron to gamma ray intensity ratio of 0.611 and a neutron to gamma ray dose first collision-rads tissue ratio of 9.361, 5 shows that a correction factor of 6.6 percent is required when the source is used as a point isotropic source of neutrons. Author

Subject Categories:

  • Nuclear Instrumentation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE