The Capture and Loss of Electrons by Fission Fragments

Abstract

We calculate the effective charge of fission fragments passing through a low pressure gas. We first compute, on a classical basis, the cross section for capture of an electron by a fission fragment of relatively arbitrary charge and velocity. We then develop a rough theory which gives the cross section for loss of an electron through interaction with a gas atom. From these two cross sections we readily obtain the effective charge. The effective charge of a fragment will increase with the pressure of the substance through which it passes. We note the probable importance of anomalous effects in hydrogen and helium. We find general agreement between theoretical predictions and experimental results.