STATE-SELECTIVE ELECTRON-CAPTURE IN COLLISIONS OF MULTICHARGED IONS WITH RYDBERG ATOMS

Authors
Citation
A. Pesnelle, STATE-SELECTIVE ELECTRON-CAPTURE IN COLLISIONS OF MULTICHARGED IONS WITH RYDBERG ATOMS, Physica scripta. T, T73, 1997, pp. 156-161
Citations number
26
Categorie Soggetti
Physics
Journal title
ISSN journal
02811847
Volume
T73
Year of publication
1997
Pages
156 - 161
Database
ISI
SICI code
0281-1847(1997)T73:<156:SEICOM>2.0.ZU;2-Q
Abstract
Atoms in a Rydberg state should be exceptional targets for a strongly- enhanced electron-capture process in collisions with multicharged ions since a quadratic increase of the cross section is expected when the binding energy of the target electron decreases. Simultaneously, becau se of the quasi-resonance of the capture process, very high orbitals s hould be populated. Laser excitation of the target atom to a Rydberg s tate, combined with a new detector based on field ionization and energ y spectrometry, has made it possible to detect very high Kr7+(n) Rydb erg states after single electron capture. A wide n distribution, up to n approximate to 100, of the capture cross section has been observed. Several collision systems composed of a Kr8+ projectile and a well-de fined Rydberg state Rb-(n(i)p) of the target atom have been investiga ted with various kinetic energies and various initial ng states (15 < n(i) < 25). The production of doubly excited Kr6+*(n(0), n) ions, aft er a two-electron capture has been investigated as well, and can be ex plained by two successive collisions with Rb(5s) and Rb(n(i)p) atoms, leading to n(0) = 10 and a wide distribution of n states.