L.E.T. effects in ionic solids. Part 1.—Chemical dissociation yields from 14N(n,p)14C events in azides and nitrates

Abstract

Greater chemical dissociation is reported in normal azides or nitrates irradiated in reactor thermal columns than for ¹⁵N-enriched salts similarly irradiated. The difference is attributed to the large cross-section for ¹⁴N(n,p)¹⁴C events with thermal neutrons and is used to derive G values for dissociation by the proton and ¹⁴C recoiling from a nuclear transformation. Values thus derived are compared with G values reported for radiations of other L.E.T. Evidence for (i) increased probability of intermediates reacting in the track, and (ii) dissociation by charge displacement processes, is discussed for nitrates at high L.E.T. Observed L.E.T. effects can be accounted for with these two processes without the need to invoke temperature effects in thermal spikes.