Effect of applied fields on positive ions in the pulsed electron-capture detector

Abstract

Experiments are reported which indicate the effect of positive ions on the measured standing current and response of the pulsed electron-capture detector (ECD). These experiments include measurements taken with a specialized ion source on an atmospheric pressure ionization mass spectrometer, and also measurements of standing current obtained from two ECDs of coaxial cylindrical geometry but having different length-to-diameter ratios. Two opposing views of the means by which positive ions might be removed from a pulsed ECD are considered. The results of this study are shown to strongly support one of these.