Atomic structure and collision dynamics with highly charged ions

Abstract

The research progresses on the investigations of atomic structure and collision dynamics with highly charged ions based on the heavy ion storage rings and electron ion beam traps in recent 20 years are reviewed. The structure part covers test of quantum electrodynamics and electron correlation in strong Coulomb field studied through dielectronic recombination spectroscopy and VUV/x-ray spectroscopy. The collision dynamics part includes charge exchange dynamics in ion-atom collisions mainly in Bohr velocity region, ion induced fragmentation mechanisms of molecules, hydrogen-bound and van de Waals bound clusters, interference and phase information observed in ion-atom/molecule collisions. With this achievements, two aspects of theoretical studies related to low energy and relativistic energy collisions are presented. The applications of data relevant to key atomic processes like dielectronic recombination and charge exchanges involving highly charged ions are discussed. At end of this review, some future prospects of research related to highly charged ions are proposed.

State-selective charge exchange cross sections in collisions of highly-charged sulfur ions with helium and molecular hydrogen

“…The review paper shows the progress and challenges of atomic structure and collision dynamics with highly charged ions. [8] Sulfur ions as an important species of the solar wind were also observed in astrophysical objects and environments. [9][10][11][12] The mysterious 3.5 keV line observed in XMM-Newton observations of the galaxy clusters in 2014 [13,14] was attributed to the emission from the charge exchange of bare sulfur ion with neutral component interactions by Gu et al [15] and has been confirmed by Shah et al experimentally.…”

Hyperfine-induced effects on Kα1 linear polarization following electron-impact excitation of heliumlike Tl79+ ions with nuclear spin I=1/2

“…Anisotropic and polarized x-ray line emissions exist in most non-thermodynamic equilibrium astrophysical plasmas, such as, solar flares [1], pulsars [2], neutron stars [3], and around accreting black holes [4], which are usually associated with excitation of highly charged ions by energetic electrons with anisotropic velocity distribution. Furthermore, they also exist in various laboratory plasmas in which the ions are excited by collisions with quasi-free electrons or by directional electron beams [5][6][7]. As widely used experimental facilities at present, both electron beam ion traps and ion storage rings can provide nearly unidirectional and monoenergetic electron or ion beams [6,7].…”

“…Furthermore, they also exist in various laboratory plasmas in which the ions are excited by collisions with quasi-free electrons or by directional electron beams [5][6][7]. As widely used experimental facilities at present, both electron beam ion traps and ion storage rings can provide nearly unidirectional and monoenergetic electron or ion beams [6,7]. When combined with modern high-resolution x-ray spectrometers or polarimeters, they were often employed to study angular distribution and linear polarization of characteristic x-ray lines emitted following various relativistic electron-ion collision processes, such as, electron-impact excitation (EIE) [8][9][10][11][12][13][14][15][16][17], dielectronic recombination [18][19][20][21][22][23][24][25][26], radiative electron capture (REC) [27][28][29][30][31], and nonradiative electron capture [32,33].…”

A simple semiempirical model for the static polarizability of ions

“…[25][26][27][28][29][30] Simultaneously, very little is known about the polarizability of molecular ions and charged clusters, with a few exceptions for some singly charged diatomic, [31][32][33][34][35][36][37][38][39][40][41][42] small polyatomic, [43][44][45] and cluster ions. [46][47][48][49][50] The noted knowledge gap on the polarizability of charged particles relates both to the difficulty of manipulating highly reactive and unstable species, such as ions, in an experiment [38,[51][52][53][54] and to the fact that the precise evaluation of electric response properties of such electrondeficient and, even more so, electron-rich systems remains a hard nut to crack for conventional quantum chemical machinery. [21,25,28,29] The accurate data on the polarizability of charged species are primarily of fundamental relevance to the interpretation of the respective spectra [18,29,[53][54][55][56] and for the calculation of ionmolecular potentials.…”