Excitation function measurements for disintegrations produced by deuterons in the heavy elements

Abstract

Excitation function measurements have been made for the (d, p) reaction in thallium, lead, bismuth and thorium, and also for the (d, n) reaction in thallium and bismuth, using deuterons up to 9 MeV energy from the Cavendish cyclotron. The previous results concerning the (d, p) reaction in platinum, gold and uranium and the (d, n) reaction in gold are also included for purposes of comparison. The energy-yield curves obtained are compared with those to be expected on theoretical grounds. The excitation function for the (d, n) reaction is approximately as predicted by the Gamow penetration theory. It is concluded that the Gamow process is responsible for very little if any of the yield of the (d, p) reaction which occurs mainly by the Oppenheimer-Phillips process. The observed ratio of the (d, p) yield to (d, n) yield at 9 MeV and its variation with deuteron energy are shown to favour the lower of the two values of the standard nuclear radius, namely, 1.4× 10^-13 cm. and 2.0×10^-13 cm., which have been considered in this paper.