This paper presents a new way of critically assessing and compacting data for electron
impact excitation of positive ions. Collision strengths Ω are scaled and then plotted as …

Cross sections have been compiled for electron-impact excitation of carbon and oxygen ions
(C II–VI and O II–VIII). A selection has been made to recommend “best” values for use. The …

Cross sections or effective collision strengths are compiled for electron-impact excitation of
helium atoms and He-like ions. An evaluation is made to identify the “best” determined …

Electron-impact excitation collision strengths for transitions between all singly excited levels
up to the n= 4 shell of helium-like argon and the n= 4 and 5 shells of helium-like iron have …

Electron-hydrogen scattering is studied in the range of incident energies from 12 to 100 eV.
The equations resulting from a six-state close-coupling expansion are supplemented by an …

Cross sections for elastic scattering and excitation of the n= 2 states of atomic hydrogen by
electrons are computed for incident energies in the range from 12 to 54 eV. The calculations …

We measure the energy-differential cross sections for collisional excitation of the soft x-ray
electric-dipole K α (x+ y+ w) emission from He-like oxygen (O vii), using an electron beam …

Aims. Spectral lines of He-like ions are among the most prominent features in X-ray spectra
from a large variety of astrophysical and high-temperature fusion plasmas. A reliable plasma …

Electron excitation rates for the ground state to n= 2 and 3 S and P levels in He-like ions
between F VIII and Mn XXIV have been determined by interpolating recent R-matrix and …

The Dirac R-matrix theory is used to calculate the collision strengths for electron impact
excitation of He-like ions (S 14+, Ca 18+ and Fe 24+) using the Dirac atomic R-matrix code …