"Radiochemical measurements on nuclear reactions induced by fast neutrons"

Abstract

Nuclear reactions induced by 14 MeV neutrons in a wide range of elements* have "been investigated by activation ' techniques. The cross sections of (n,p), (n,pn), (n,ɚ), (n, ɤ ) and (n,2n) reactions have been measured and their values are discussed with reference to the theoretical predictions of different nuclear models. The 14 MeV neutrons were produced hy the H(^3)(d,n)He(^4) reaction, the deuterons being accelerated to the optimum energy by a Cockroft-Walton accelerator. A method for the accurate monitoring of fast neutron fluxes in conditions of poor geometry has been developed. Counting equipment has been calibrated relative to a 4 π counter. Greater accuracy in the determination of absolute disintegration rates, in conjunction with the separation of induced activities by radiochemical procedures, is considered the greatest improvement on the results of previous workers. A recent report of (n,He(^3)) reactions, induced by 14 MeV neutrons with measurable cross sections, has been investigated, but the results could not be reproduced.* Magnesium, aluminium, argon manganese, cobalt, arsenic, iodine, barium, gold, mercury, bismuth. Irradiations of natural ytterbium and osmium have been performed in an attempt to observe new activities. 9.8 Minute rhenium, induced, in osmium, has been re-assigned to Re(^192)