Title Theoretical study of direct and indirect single ionisation by electron impact /
Translation of Title Tiesioginės ir netiesioginės viengubos jonizacijos elektronų smūgiais tyrimas.
Authors Pakalka, Saulius
DOI 10.15388/vu.thesis.235
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Pages 108
Keywords [eng] ionisation ; cross section ; modelling ; correlation effects
Abstract [eng] The dissertation analyses the processes of single ionisation with electron impact using the distorted wave approximation. The work focuses on W5+, W25+, W26+, Fe3+ and Se3+ ions. The atomic data of these ions are important and have practical application perspectives for understanding and controlling astrophysical processes and thermonuclear plasma dynamics. The direct and indirect ionisation processes of ions are analysed, and the cross sections of the ionisation effect are determined. The correlation effects of Fe3+ and W5+ ions were also investigated and the experimental data of these ions and Se3+ ion were explained for the first time. The introduction discusses the importance of plasma studies and the need to investigate ionisation in iron, selenium, and tungsten. The work aims to investigate the processes of single ionisation by electron impact using the distorted wave method and to propose more accurate methods. The main theory is discussed in the theoretical chapter: electron impact ionization, wave functions, radiation and Auger transitions, resonant excitation-double autoionisation process, distorted wave approximation, cross section scaling coefficient, correlation effects, modelling of metastable states. The dissertation concludes with the main conclusions that are related to the defended statements. The dissertation is prepared in English, its volume is 103 pages. The dissertation consists of content, the list of author's publications and conference papers, the list of abbreviations used in the dissertation, introduction, theory overview, the results section, conclusions, and the list of used literature with 98 sources. The dissertation contains 33 illustrations, 5 tables and 1 appendix.
Dissertation Institution Vilniaus universitetas.
Type Doctoral thesis
Language English
Publication date 2021