Recent experiments on near-threshold electron-impact excitation of multiply charged ions
- Oak Ridge National Lab., TN (United States). Physics Div.
- Univ. of Colorado, Boulder, CO (United States)
- Chungnam National Univ., Daejon (Korea, Republic of). Dept. of Physics
- University Coll. London (United Kingdom). Dept. of Physics and Astronomy
- St. Francis Zavier Univ., Antigonish, Nova Scotia (Canada). Dept. of Physics
Some recent measurements of excitation of multiply charged ions by electrons studied in beam-beam experiments are highlighted. The emphasis is on absolute total cross sections measured with the merged electron-ion beams energy-loss (MEIBEL) technique, although some results obtained with the crossed-beams fluorescence method are also presented. The MEIBEL technique allows the investigation of optically-allowed and forbidden transitions with sufficient energy resolution, typically about 0.2 eV, to resolve resonance structures in the cross sections. Results from the JILA/ORNL MEIBEL experiment on dipole-allowed transitions in several ions demonstrate the success of various theoretical methods in predicting cross sections in the absence of resonances. Comparisons of R-matrix calculations and measured cross sections for spin-forbidden transitions in Mg-like Si{sup 2+} and Ar{sup 6+}, however, show that further refinements to the theory are needed in order to more accurately predict cross sections involving significant contributions from dielectric resonance`s and interactions between neighboring resonances.
- Research Organization:
- Oak Ridge National Lab., Physics Div., TN (United States); National Inst. of Standards and Technology, Boulder, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464; AI05-86ER53237
- OSTI ID:
- 672024
- Report Number(s):
- ORNL/CP-97360; CONF-980365-; ON: DE98004882; BR: AT5030100; TRN: 99:000451
- Resource Relation:
- Conference: 11. APS topical conference on atomic processes in plasmas, Auburn, AL (United States), 23-26 Mar 1998; Other Information: PBD: Apr 1998
- Country of Publication:
- United States
- Language:
- English
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