Statistical γ-ray multiplicity distributions in Dy and Yb nuclei

The statistical γ-ray multiplicity distributions following the reactions 163Dy(3He,αxn)162-xDy and 173Yb(3He,αxn)172-xYb have been studied. The mean value and standard deviation have been extracted as functions of excitation energy. The method is based on the probability distribution of k-fold events, where an α-particle is observed in coincidence with signals in k γ-ray detectors. Techniques for isolating statistical γ-rays and subtracting random background, cross-talk and neutron contributions are discussed. 22 refs., 10 figs., 3 tabs