Absolute calibration of relative electron attachment cross sections measured by crossed-beams experiments

Abstract

Relative dissociative electron attachment cross sections measured in crossed beams apparatus may be placed on an absolute scale using absolute attachment rate constants measured in swarm type experiments. We discuss here possible pitfalls and in particular the influence of the shape of the cross section curve on the necessary integration involved in such a calibration procedure. Using as an example recently measured data for CCl 2F 2 and CCl 3H we will demonstrate the importance of using a full integration method instead of previously used simple methods involving for instance the relationship σ {ϵ} = k( T)/〈v〉.