Theoretical calculation of the relative abundance between He- and Li-like Ti under the coronal condition

Abstract

This paper provides a theoretical calculation of the relative abundance between He- and Li-like Ti in the electronic temperature range from 0.1 to 20 keV under the coronal conditions. The results show that the abundance of Li-like Ti is <6 percent of He-like Ti as the electronic temperature exceeds 3 keV , and this percentage will further decrease when the photon-ionization is considered. Thus, it is proven that for the Ti plasma it is approximately true that there are only two charge states (H- and He-like) in the plasma when the electronic temperature is beyond 3 keV . The results also show that the abundance of Li-like Ti will reach a maximum in temperatures range from 0.6 to 0.7 keV . In this paper, the Younger formula is used to estimate the electron–ion collision rates and it is shown that this formula is in a good agreement with experiment data and is better than other theoretical methods. Dielectronic recombination of He-like Ti is considered by a full quantum mechanics method and the total electronic recombination rates of He-like Ti will reach the maximum values at the temperature 2.9 keV , which is close to the plasma temperature of 3 keV formed as in Shepard et al. (Phys. Rev. E 53 (1996) 5291).