Correction factors for the effect of thickness on the selfscattering, self-absorption, and backscattering of beta particles from indium foils were determined for irradiated foils of 0.03 to 100 mg/cm/sup 2/. The data were corrected for the activity produced by epithermal neutrons, self-shielding of thermal neutrons by the foil during irradiation, the backscatter from the foil support, and the contributions of gamma and x rays to the counting rate. The multiple beta spectra of indium produced a minimum in the self-absorption and self-scattering correction curve in the GM detector at approximately 1 mg/cm/ sup 2/ and a maximum at approximately 12 mg/cm/sup 2/. The selfabsorption curve for indium in the 2 pi counter has the expected shape for a beta emitter with multiple spectra. The self-scattering and self-absorption correction factors for a 100 mg/cm/sup 2/ indium foil are approximately 1.5 for a GM detector at 7% geometry and approximately 3 for a 2 pi counter. (D.L.C.)
Date: October 1, 1955
Creator: Koontz, R. L.; Greenfield, M. A. & Jarrett, A. A.
Abstract: During the course of power run 14 on the Sodium Reactor Experiment (SRE) at low power, the temperature difference among various fuel channels was found to be undesirably high. Normal operating practices did not succeed in reducing this temperature difference to acceptable values and on July 26, 1959, the run was terminated.