Resonant transfer excitation followed by X-ray for boron-like ions

Authors: HASSAN RAMADAN

Abstract: Theoretical cross sections for resonant transfer excitation followed by x-ray emission (RTEX) are calculated for the collisions of some ions in the series of the Boron-like ions with H_2 as a target. The calculations have been done for C II, N III, O IV, F V, Ar XIV and Fe XXII ions by folding their dielectronic recombination (DR) cross sections over the momentum distribution (Compton profile) of H_2 target gas. Calculations have been performed from both ground and metastable initial states, in LS - coupling, allowing for \triangle n = 0 excitations. In the present work, the RTEX cross sections of the ions C II, N III, O IV and F V exhibit one peak behavior, but shows two overlapped peaks in case of Ar XIV ion. RTEX cross section gives two separated peaks for Fe XXII ion. It is expected that the new results would lead to a revision of the spectral diagnostics of the B-like ions in laboratory and astrophysical sources, in particular the x-ray spectra observed from solar flares and tokamaks.

Keywords: Transition probability, resonant transfer excitation

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