Observation of Coulomb focusing of autoionization electrons produced in low-energyHe++He collisions

Abstract
We report observation of a significant enhancement in the intensity of target and projectile autoionizing electrons produced in low-energy (215 keV) He++He collisions. The target electron intensity is strongly peaked at 0° and confined to an angular range of ≊5° about the incident beam direction, while the projectile electron intensity shows a similar enhancement at 180°. We attribute this effect to Coulomb focusing, a new aspect of post-collision interaction which results from the deflection of the ejected electrons in the Coulomb field of the receding spectator ion.