Zero degree target electron spectroscopy: Double excitation, autoionization of helium in fast e, H{sup +}, He{sup +}, and He{sup 2+} collisions
- Univ. of Nevada, Reno, NV (United States)
The authors have measured zero degree high-resolution spectra and double differential cross sections (DDCS) for double - excitation-autoionization of Helium atoms. They have also measured direct ionization DDCS at zero degree observation angle. The cross sections are absolutely calibrated. Electrons from the energy 150 to 1000 eV, protons from 100 keV to 1.5 MeV, He{sup +} from 400 keV to 1.5 MeV, and He{sup 2+} from 400 keV to 1.6 MeV were used as projectiles. The zero degree observation angle provides a unique opportunity to maximize the interaction between the emitted electron, the ionized target atom, and the charged projectile particles. The doubly excited autoionizing (2lnl`) states of He have been observed as a function of the collision conditions such as impact velocity, projectile charge sign, and type of projectile, specifically for the dominating (2p{sup 2}){sup 1}D {r_arrow} (ls{epsilon}d) and (2s2p){sup 1}P{sup 0} {r_arrow} (ls{epsilon}p) channels.
- OSTI ID:
- 199651
- Report Number(s):
- CONF-941129--
- Country of Publication:
- United States
- Language:
- English
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