Photoionization of the excited 3s3p^1,3P^ostates of atomic magnesium

Abstract

Calculational results for the photoionization cross sections leading to the ionic Mg + (3s, 3p, 4s and 3d) states from the excited 3s3p 1,3 P o states of atomic magnesium are reported in the energy region from the first ionization threshold up to the Mg + (4p) threshold limit. For these calculations, we have used an enhanced non-iterative variational R-matrix approach combined with multichannel quantum-defect theory at the R-matrix surface. Autoionizing doubly excited 1,3 S, 1,3 P and 1,3 D resonance structures converging to the Mg + (3p, 4s, 3d and 4p) thresholds are discussed with resonant energies E r , effective quantum numbers n * and widths . The present photoionization cross sections are in good agreement with previous available calculations. There is excellent agreement between length and velocity gauges in our calculations.

Multiphoton ionization through the triplet states of Mg by linearly and circularly polarized laser pulses

“…Moccia and co-workers [5] developed a nonempirical description of the core-polarization effects of Mg employing a basis set of modified Slater-type orbitals to study the transitions between the 3snl 1,3 L (L = S, P, D , and F ) states of Mg. Luc-Koenig and co-workers [6] used an eigenchannel R-matrix and multichannel quantum defect theory (MQDT) to investigate twophoton ionization of Mg atom. Lately, Fang and Chang [7] studied single-photon ionization from the excited singlet and triplet states of Mg below the Mg 2+ threshold using an approach based on the B -spline functions and Kim [8] studied single-photon ionization from the 3s3p 1,3 P states with a R-matrix method combined with MQDT. Most recently Fang and Chang has developed a B -spline-based complex rotation method with spin-dependent interaction to calculate atomic photoionization of Mg with singlet-triplet mixing [9].…”

Single photoionization of aluminum-like P2+ and magnesium-like P3+

“…The analyses given for the single photoionization of ground state magnesium by Hsin-Chang and Keh-Ning [13], of excited magnesium by Dae-Soung [15] and, of isoelectronic Al + by West et. al [27] are relevant for the interpretation of the present experiment in the case of the single photoionization of P 3+ .…”

“…Butler et al [12] used the close-coupling approximation to study the Mg isoelectronic sequence in the collisional formalism. Chi and Huang [13], used a multiconfiguration approximation theory and found three Rydberg series of the fine structure splitting in the initial states of Mg. Dae-Soung and Tayal [14] and Dae-Soung [15], performed variational R-matrix calculations to derive position resonance energies, quantum defects and widths for several doubly excited states of Mg. Hsiao and Huang [16] used multiconfiguration relativistic random-phase approximation to study atoms with two valence electrons outside a closed shell.…”

Opacity

“…The close-coupling R-matrix method (see Sect. 3.1.8) is also used to obtain photoionization cross sections (Nahar and Pradhan 1997, close-coupling R-matrix; Kim 2001, R-matrix and multichannel quantum defect theory at R-matrix surface; Singh and Mohan 2002, close-coupling R-matrix) including cross sections from excited states (Kim 2001;Singh and Mohan 2002). Gallagher et al (1988) compare and contrast computational approximations (plane waves, single-and two-center Coulomb waves, multiple scattering X˛, local molecular and static-exchange potentials, and coupled-channel approximations) as applied to molecular photoionization calculations.…”