Contribution of Field-Ionized Rydberg Atoms in Observations on Convoy Electrons

Abstract
An experiment is described demonstrating that for fast-ion bombardment of thin foils, projectile Rydberg atoms and convoy electrons emerge with comparable probabilities. These Rydberg atoms can readily ionize in the fields of electron spectrometers employed for measurements on convoy electrons, producing beam-velocity electrons which contribute significantly to the "cusp electron" spectra observed. This Rydberg contribution to the shape and intensity of the cusp peak has not been taken into account in previous treatments.