Theory and experiment in the electron impact excitation of Li+
- 28 March 1991
- journal article
- Published by IOP Publishing in Journal of Physics B: Atomic, Molecular and Optical Physics
- Vol. 24 (6) , 1411-1421
- https://doi.org/10.1088/0953-4075/24/6/025
Abstract
The low-energy electron impact excitation of helium-like Li+ is investigated using the R-matrix method. The lowest nineteen states (i.e. with a principal quantum number n4) are explicitly included in the target description. Collision strengths for exciting the n=2 states are compared with other methods, particularly five-state (n2) and eleven-state (n3) calculations. Attention is paid to the 11S-23P transition, for which experimental total emission cross sections are available. The authors show the importance in calculating reliable collision strengths for exciting target states with a principal quantum number n of including coupling to higher n states. There is now no significant difference between theory and experiment at low impact energies (up to 6 Ryd), providing cascade contributions are accounted for in the interpretation of the experimental measurements.Keywords
This publication has 20 references indexed in Scilit:
- Differential excitation cross sections for electron impact on: A study of continuum coupling effectsPhysical Review A, 1990
- Differential cross sections for the electron-impact excitation of He-like ions: 2and 2Physical Review A, 1988
- Electron excitation in helium: including the n=4 levels in an R-matrix calculationJournal of Physics B: Atomic and Molecular Physics, 1987
- Atomic data for opacity calculations. II. Computational methodsJournal of Physics B: Atomic and Molecular Physics, 1987
- Electron-impact excitation of Li ii: A model study of wave-function and collisional approximations and of resonance effectsPhysical Review A, 1985
- A new version of the general program to calculate atomic continuum processes using the r-matrix methodComputer Physics Communications, 1978
- Electron impact excitation of Be+:a benchmark studyJournal of Physics B: Atomic and Molecular Physics, 1977
- CIV3 — A general program to calculate configuration interaction wave functions and electric-dipole oscillator strengthsComputer Physics Communications, 1975
- A measurement of cross sections for the 1S-2S excitation of He+ions by electron impactJournal of Physics B: Atomic and Molecular Physics, 1973
- andStates of the Helium Isoelectronic Sequence up toPhysical Review A, 1971