In this paper we formulate a theory for the analysis of resonant enhanced multi photon ionization processes in molecules. Our approach consists of viewing the (n + m) photon ionization process from an isotropic initial state as m -photon ionization out of an oriented, excited state. The orientation in this resonant state, which is reached by n -photon excitation from the initial state, is nonis...

The first three ionization potentials of americium are calculated using ab initio spin-orbit configuration interaction techniques. These results are favorably compared with experimental and theoretical work. The lowest two ionization potentials are accurately determined using wavefunctions constructed as simple single and double substitutions from a self-consistent field reference configuration...

Wehave investigated the uncertainty in the ionization and recombination rates for iron and its impact on the derivation of the iron elemental abundance fromX-ray emission spectra. Most uncertainty is found in the dielectronic recombination rates for iron ions with L-shell outer electrons. The quantitative effect of this uncertainty on the derivation of the iron abundance depends on the spectral...

Gregory Lapicki,* G. A. V. Ramana Murty, G. J. Naga Raju, B. Seetharami Reddy, S. Bhuloka Reddy, and V. Vijayan Department of Physics, East Carolina University, Greenville, North Carolina 27858, USA Swami Jnanananda Laboratories for Nuclear Reasearch, Andhra University, Visakhapatnam-530 003, India Institute of Physics, Sachivalaya Marg, Bhubaneswar-751 005, India (Received 9 February 2004; pub...

The Independent Event Model (IEVM) is used to analyze collision processes for systems with three and four electrons, in situations where up to three active electrons are involved and dynamical correlation effects play a major role. The model is applied to single electron loss and loss-ionization processes. All the possible ionization mechanisms for both collision partners in each exit channel a...

We have simulated ionization of purine nucleic acid components in the gas phase and in a water environment. The vertical and adiabatic ionization processes were calculated at the PMP2/aug-cc-pVDZ level with the TDDFT method applied to obtain ionization from the deeper lying orbitals. The water environment was modeled via microsolvation approach and using a nonequilibrium polarizable continuum m...

Using a three-dimensional semiclassical model, we study double ionization for strongly driven He fully accounting for magnetic field effects during the propagation in time. For linearly and slightly elliptically polarized laser fields, we show that recollisions and the magnetic field combined act as a gate. This gate favors more transverse—with respect to the electric field— initial momenta of ...

We describe a method which uses a rather detailed model of coronal loop hosting a siphon flow as a diagnostic tool to interpret solar UV and X–ray observations in selected bands and lines. We apply the method to investigate the deviations from ionization equilibrium induced by stationary plasma flows confined in coronal loops and their effects on the UV and EUV emission lines observed by the in...

With a classical ensemble model that includes electron correlations during the whole ionization process, we investigate strong-field sequential double ionization of Ar by elliptically polarized pulses at the quantitative level. The experimentally observed intensity-dependent three-band or four-band structures in the ion momentum distributions are well reproduced with this classical model. More ...