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

We report observation of a significant enhancement in the intensity of target and projectile autoionizing electrons produced in low-energy (2--15 keV) He/sup +/+He collisions. The target electron intensity is strongly peaked at 0/degree/ and confined to an angular range of /approx/5/degree/ about the incident beam direction, while the projectile electron intensity shows a similar enhancement at 180/degree/. We attribute this effect to /ital Coulomb/ /ital 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.