Resonant dielectronic and direct excitation in crystal channels

• Published in: Physical review letters 1989-08, Vol.63 (7), p.742-745
• Main Authors: DATZ, S, VANE, C. R, ROSSEEL, T. M, DITTNER, P. F, GIESE, J. P, GOMEZ DEL CAMPO, J, JONES, N. L, KRAUSE, H. F, MILLER, P. D, SCHULZ, M, SCHONE, H
• Format: Article
• Language: English
• Subjects: 360605 - Materials- Radiation Effects; ABSORPTION; Atomic and molecular collision processes and interactions; Atomic and molecular physics; BOUND STATE; CALCIUM IONS; CATIONS; CHANNELING; CHARGE STATE; CHARGED PARTICLES; ELECTROMAGNETIC RADIATION; ELECTRONS; ELEMENTARY PARTICLES; ELEMENTS; ENERGY LEVELS; Exact sciences and technology; EXCITED STATES; FERMIONS; ION CHANNELING; IONIZING RADIATIONS; IONS; LEPTONS; MATERIALS SCIENCE; Physics; RADIATIONS; RELAXATION; RESONANCE ABSORPTION; Scattering of atoms, molecules and ions; SEMIMETALS; SILICON; SPECTRA; SULFUR IONS; TITANIUM IONS; X RADIATION; X-RAY SPECTRA; YIELDS
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.63.742

We have observed dielectronic and direct excitation of H-like S{sup 15+} and Ca{sup 19+} and He-like Ti{sup 20+} ions in silicon channels caused by collision with weakly bound target electrons which behave as a free-electron gas. As {ital in} acuo, relaxation of the doubly excited states can occur radiatively leading to ions of decreased charge, but in a crystal channel collisional effects can cause double ionization. The effects are seen in both the x-ray yields and charge-state fractions, and, in the case of Ti{sup 20+}, in charge-state x-ray coincidences.