2-ELECTRON EXCITATION TO RYDBERG LEVELS IN FAST I6+ ON HYDROGEN COLLISIONS

The emission of electrons in the forward direction in collisions of 0. 3 MeV/u I6+ with H-2 has been studied, and strong autoionization peaks are observed on the shoulder of the cusp peak. The energies of these autoionization lines in the projectile rest frame are determined by hi gh-resolution electron spectroscopy. Using the electron projectile fin al charge state coincidence technique, we probe different collision me chanisms, which create continuum electrons that are slow in the projec tile rest frame. We conclude that the observed autoionization lines ar e due to two electron excitation to projectile Rydberg levels.