Electron-impact-excitation cross sections of lithiumlike ions
- Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)
- P. N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow 117924 (Russia)
- Electronic Structure of Materials Centre, School of Physical Sciences, The Flinders University of South Australia, G.P.O. Box 2100, Adelaide 5001 (Australia)
We present an easy to use expression for cross sections of electron-impact-induced 1s{sup 2}nl{r_arrow}1s{sup 2}n{sup {prime}}l{sup {prime}} excitation transitions with 2{le}n{le}n{sup {prime}}{le}4 in multiply charged ions of lithium isoelectronic sequence. This expression is based on our computations by convergent close-coupling (CCC) and Coulomb-Born with exchange and normalization (CBE) methods. We show scaling of the CCC and CBE cross sections with atomic number Z and use this scaling for presentation of the cross-section data. For 6{le}Z{le}30 the scaling is accurate to better than {plus_minus}20{percent} at any energy except in the vicinity of resonances. Contributions from indirect excitation channels do not scale with Z; however, for calculation of excitation rates it is enough to average locally these contributions over energy and to take them into account in a frame of a general scaling-based expression for the cross sections. For excitation rates, total inaccuracy caused by all simplifications in the cross-section presentation is likely to be less than {plus_minus}30{percent} even for most risky cases. This assessment is based on comparison of excitation rates, computed using our scaling-based expression for the cross sections, with the excitation rates, computed using high-resolution (CCC and R matrix) cross sections and experimental data. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 543798
- Journal Information:
- Physical Review A, Journal Name: Physical Review A Journal Issue: 5 Vol. 56; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
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