Resonance in Nuclear Photo-Effects

Abstract

IN connexion with the remarkable selectivity of nuclear photo-effects of heavy elements indicated by experiments, it was pointed out in a recent note in NATURE¹ that such photo-effects might provide a means of examining certain features of the mechanism of excitation of atomic nuclei not disclosed by ordinary experience about nuclear reactions by collisions. In fact, the probability of excitation of a nucleus by monochromatic radiation depends on the degree to which forced oscillations of given frequency of the nuclear matter can be produced, and experiments on the variation of the yield of the photo-effects with radiation frequency would therefore allow a direct estimate of the strength of coupling between the different modes of oscillation into which the collective motion of the nuclear particles may approximately be resolved.