Measurements of resonance neutron self shielding factors for gold and silver using slowing-down time spectrometer

The resonance neutron self-shielding factors for cylindrical samples of various thicknesses of gold and silver have been measured in the narrow energy groups with a lead slowing-down time spectrometer as a neutron source. Calculation by Wigner's rational approximation gives 10 -- 20% smaller self shielding factors than the experimental ones except for the limiting cases of sample thickness. The collision probability theory, on the other hand, was found to give rather good agreement with the experiments in all the measured cases. (auth.)