On the Resonance Capture of Slow Neutrons and Emission of Gamma-Rays

Abstract

Intensity of gamma-rays emitted from Fe, Cd, Hg and Bi by slow neutron capture was measured as a function of thickness of paraffin layer interposed between a D+D neutron source and a detector. From analyscs of the obtained gamma-ray intensity curves and measurements of energy by boron absorption method it is shown that Hg has a clear resonance neutron group of about 10 e.V. in energy, Cd has several groups of energies from several tens of e.V. to a few e.V. and the mean energy of these groups plus the residual part of the first group (Er=0.17 c.V.) not absorbed by Cd filter of 0.43 g/cm ² thick is about 2 e.V., Bi has resonance group giving a maximum of gamma-ray intensity at about 57 cm of paraffin thickness, and Fe has no distinct resonance groups