Energy levels, radiative rates and electron impact excitation rates for transitions in Be-like Ti XIX

Abstract

We report calculations of energy levels, radiative rates, and electron impact excitation rates for transitions in Li-like ions with 12 ≤ Z ≤ 20. The GRASP (general-purpose relativistic atomic structure package) is adopted for calculating energy levels and radiative rates, while for determining the collision strengths and subsequently the excitation rates, the Dirac atomic R-matrix code (DARC) is used. Oscillator strengths, radiative rates, and line strengths are reported for all E1, E2, M1, and M2 transitions among the lowest 24 levels of the Li-like ions considered. Collision strengths have been averaged over a Maxwellian velocity distribution, and the effective collision strengths obtained are reported over a wide temperature range up to 10 7.4 K. Additionally, lifetimes are also listed for all calculated levels of the above ions. Finally, extensive comparisons are made with available results in the literature, as well as with our parallel calculations for all parameters with the Flexible Atomic Code (FAC) in order to assess the accuracy of the reported results.

Energy levels, radiative rates and electron impact excitation rates for transitions in C iii

“…Aggarwal & Keenan (2012) and references therein). The absorption oscillator strength (fij) and radiative rate Aji (in s −1 ) for all types of transition i → j are related by the following expression:…”

“…(7) of Aggarwal & Keenan (2012). As stated earlier and in our work on other Be-like ions, we have adopted the relativistic darc code for calculating Ω.…”

Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Ga XXX, Ge XXXI, As XXXII, Se XXXIII and Br XXXIV

“…These data are also required for the modelling of fusion plasmas [10]. Therefore, in a series of papers we have already reported atomic data for He-like ions up to Z=30 [11] - [19] and for Z=36, i.e. Kr XXXV [20].…”

Division B Commission 14 Working Group: Collision Processes

“…For He-like ions data is now available covering most ions from Mg For Li-like ions data has been calculated for ions from Mg 9 + to Ni 25+ (Aggarwal & Keenan 2012a, Aggarwal & Keenan 2013a. For Be-like ions data has been presented for ions from B + to Zn 26+ (Fernández-Menchero et al 2014a), and also Cl 13+ , K 15+ and Ge 28+ (Aggarwal & Keenan 2014d) and Ti 18+ (Aggarwal & Keenan 2012f). For B-like ions data covering from C + to Kr 31+ (Liang et al 2012), and also Al 9+ (Aggarwal & Keenan 2014a) (Palay et al 2012, Storey et al 2014, O 4+ and O 5+ (Elabidi & Sahal-Bréchot 2013), Ne 4+ (Dance et al 2013), Mg 2+ and Al 3+ (Elabidi 2014), Mg 5+ (Tayal 2012a), Mg 7+ (Grieve et al 2013), Si + (Aggarwal & Keenan 2014b), Si 6+ (Sossah & Tayal 2014), Si 7+ (Tayal 2012b, S 2+ (Hudson et al 2012b, Grieve et al 2014, S 14+ and S 15+ including recombination (Mahmood et al 2012), Cl 2+ (Sossah & Tayal 2012), Ca 13+ (Dong et al 2012), Sc + (Grieve et al 2012) , Ni 17+ (Hudson et al 2012a), Ge + (Smirnov 2014), Nb +11 and Mo +12 (Liang et al 2014), Sn 13+ including ionization (Liu et al 2014b), W 3+ including ionisation (Ballance et al 2013), and Au 51+ (Fan et al 2014).…”