1. Mixed-State Ionic Beams: An Effective Tool for Collision Dynamics Investigations
- Author
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Theo J. M. Zouros, I. Madesis, E. P. Benis, S. Nanos, and A. Laoutaris
- Subjects
Nuclear and High Energy Physics ,mixed-state beams ,Ion beam ,Li-like states ,Be-like states ,01 natural sciences ,hollow states ,010305 fluids & plasmas ,Ion ,Metastability ,0103 physical sciences ,metastable states ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,010306 general physics ,Spectroscopy ,cascade feeding ,Physics ,Auger electron spectroscopy ,electron transfer excitation ,electron excitation ,zero-degree Auger projectile spectroscopy ,Condensed Matter Physics ,electron transfer ,Atomic and Molecular Physics, and Optics ,atomic_molecular_physics ,Electron excitation ,lcsh:QC770-798 ,SIMION ,Atomic physics ,He-like states ,Beam (structure) ,Excitation - Abstract
The use of mixed-state ionic beams in collision dynamics investigations is examined. Using high resolution Auger projectile spectroscopy involving He-like ( 1 s 2 1 S , 1 s 2 s 3 , 1 S ) mixed-state beams, the spectrum contributions of the 1 s 2 s 3 S metastable beam component is effectively separated and clearly identified. This is performed with a technique that exploits two independent spectrum measurements under the same collision conditions, but with ions having quite different metastable fractions, judiciously selected by varying the ion beam charge-stripping conditions. Details of the technique are presented together with characteristic examples. In collisions of 4 MeV B 3 + with H 2 targets, the Auger electron spectrum of the separated 1 s 2 s 3 S boron beam component allows for a detailed analysis of the formation of the 1 s 2 s ( 3 S ) n l 2 L states by direct n l transfer. In addition, the production of hollow 2 s 2 p 1 , 3 P doubly- and 2 s 2 p 2 2 D triply-excited states, by direct excitation and transfer-excitation processes, respectively, can also be independently studied. In similar mixed-state beam collisions of 15 MeV C 4 + with H 2 , He, Ne and Ar targets, the contributions of the 1 s 2 , 1 s 2 s 3 , 1 S beam components to the formation of the 2 s 2 p 3 , 1 P states by double-excitation, 1 s &rarr, 2 p excitation and transfer-loss processes can be clearly identified, facilitating comparisons with theoretical calculations.
- Published
- 2018
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