Abstract
Simultaneous ionization and excitation of helium atoms by electron impact is observed by the coincidence detection of the radiated 30.4 nm photon and one outgoing electron. The polarization and alignment of the state are determined. In the collision all three electrons change state, one electron is excited to an empty orbital leaving the final ionic state, and two electrons are in continuum final states. A photon decay mode is observed for the multiply excited neutral states below the level of the helium ion to the ionic state. There are no previous coincidence observations.
- Received 17 June 1996
DOI:https://doi.org/10.1103/PhysRevLett.77.3098
©1996 American Physical Society