Abstract
The absolute number of gamma-ray quanta emitted from a known number of Cu nuclei by the action of D-D neutrons (2.52MeV) was measured by Geiger-Müller counters of known efficiencies, and the number of incident neutrons was measured by a high pressure ionisation chamber filled with hydrogen and nitrogen. Thus the cross section of inelastic scattering of D-D neutrons by Cu nuclei was obtained to be
σinel=(1.9±0.2)×10-24cm2.
By taking this value of Cu as standard σinel of other elements could be determined from the known relative values of σinel