Energy levels, radiative rates and electron impact excitation rates for transitions in Fe xiv

Abstract

Energies and lifetimes are reported for the lowest 136 levels of Fe XIV, belonging to the (1s 2 2s 2 2p 6 ) 3s 2 3p, 3s3p 2 , 3s 2 3d, 3p 3 , 3s3p3d, 3p 2 3d, 3s3d 2 , 3p3d 2 and 3s 2 4 configurations. Additionally, radiative rates, oscillator strengths and line strengths are calculated for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions. Theoretical lifetimes determined from these radiative rates for most levels show satisfactory agreement with earlier calculations, as well as with measurements. Electron impact excitation collision strengths are also calculated with the Dirac atomic R-matrix code (DARC) over a wide energy range up to 260 Ryd. Furthermore, resonances have been resolved in a fine energy mesh to determine effective collision strengths, obtained after integrating the collision strengths over a Maxwellian distribution of electron velocities. Results are listed for all 9180 transitions among the 136 levels over a wide range of electron temperatures, up to 10 7.1 K. Comparisons are made with available results in the literature, and the accuracy of the present data is assessed.

Electron impact excitation of N3+using theB-splineR-matrix method: importance of the target structure description and the size of the close-coupling expansion

“…FernandezMenchero [13], however, showed that the different results were simply due to variations in the description of the target structure among the calculations. Similar criticism of ICFT was put forward by Aggarwal et al regarding the ion Fe 13+ [17], but their arguments were again rebutted by Del Zanna et al [14].…”

Uncertainties on atomic data. A case study: N iv

“…The Aggarwal & Keenan (2014) calculations adopted much smaller configurationinteraction (CI) and close-coupling (CC) expansions than the previous study, so significant differences are to be expected. Indeed, carried out a new ICFT calculation with the same CC/CI expansions as that one adopted by Aggarwal & Keenan (2014) and found excellent agreement between the DARC and ICFT results. The main differences between the smaller DARC and the larger ICFT calculation was the CC expansion used.…”

“…There are several examples in the literature, some of which have been recently reviewed by Aggarwal (2017). For example, Aggarwal & Keenan (2014) used the Dirac Atomic R-matrix Code (DARC) of P. H. Norrington and I. P. Grant to calculate effective collision strengths for the important coronal Fe xiv. They found large discrepancies with the results obtained by with the Intermediate Coupling Frame Transformation (ICFT) R-matrix method (Griffin et al 1998).…”

Application of mathematics calculation for microstates and description of the p2 electron configuration

“…Both angular momenta should be presented by vectors which have length and direction. Vectors will be identified by letters, their projections with m Also, the differences between these projections (h) should be integers (11)(12)(13)(14)(15)(16)(17)(18)(19). The above mentioned is illustrated on Figure 6 for an electron on р-АО.…”