Resonance structure and absolute cross sections in near-threshold electron-impact excitation of the 4s21S→4s4p

Superelastic Scattering Of Electrons From Highly Charged Ions With Inner Shell Vacancies

“…The deexcitation of this excited state to the He͑1s 2 1 S͒ ground state corresponds to the time-reversed process of electron-impact excitation with electron exchange. A similar time-reversed process was observed by Bannister et al [3] in the near-threshold excitation of the 4s 2 1 S ! 4s4p 3 P intercombination transition in Kr 61 , where resonance structures were observed in the total electron-impact excitation cross section.…”

RelativisticR-matrix close-coupling method based on the effective many-body Hamiltonian: electron-impact excitation of electric dipole-allowed and spin-forbidden transitions of the S4 +ion

“…Since the accuracy of the predicted electron-impact excitation cross sections forms the basis of plasma temperature and density diagnostics [3][4][5][6], refinement and implementation of reliable theoretical methods to predict the cross sections continue to be of special importance. Experimental benchmarks by which to compare the accuracy of the theoretical methods have been provided by energy-loss merged electron-ion-beams [7][8][9][10][11] and electronbeam ion trap (EBIT) experiments [12,13]. The R-matrix version of the close-coupling (CC) theory is the most efficient and successful for simulating low-energy collision processes [14][15][16][17][18][19][20][21][22][23][24][25][26].…”

Relativistic R-matrix close-coupling method based on the effective many-body Hamiltonian: electron-impact excitation of the 3s2 1S0–3s3p1P1o electric dipole-allowed transition of the Ar6+ ion1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

“…Recent merged electron-ion beams [2][3][4][5] and electronbeam ion trap (EBIT) experiments [6][7][8][9] for measuring differential and total cross sections have provided important experimental benchmarks for theoretical many-body methods employed to calculate electron-ion excitation processes. A number of theoretical calculations using the R-matrix close coupling (CC) and distorted-wave methods have been carried out to provide the atomic collision data that underpin the basis for understanding the EIE processes.…”