The double ionization of helium in the strong-field limit has been studied using an electron-ion coincidence technique. The observed double ionization electron energy spectra differ significantly from the single ionization distributions. This gives new support to the rescattering model of double ionization and explicitly reveals the role of backward electron emission following the e-2e ionizing...

We studied the ionization probability of Na atoms in an intense Ti–sapphire laser at 800 nm versus the laser pulse duration. The ionization probabilities for the Na(3s) and Na(3p) states were found to vary non-monotonically with the pulse duration at a constant peak laser intensity. The abnormal (non-monotonic) pulse duration dependence was traced to the competition between resonant and non-res...

We report on the observation of discrete structures in the electron energy distribution for strong field double ionization of argon at 394 nm. The experimental conditions were chosen in order to ensure a nonsequential ejection of both electrons with an intermediate rescattering step. We have found discrete above-threshold ionization like peaks in the sum energy of both electrons, as predicted b...

We study a time-dependent hydrogen ionization in the atmosphere of SN 1987A during the first month after the explosion. The model includes kinetics of hydrogen ionization and excitation, molecular hydrogen kinetics, and a time-dependent energy balance. The primary strong effect of the time-dependent ionization is the enhanced hydrogen ionization compared to the steady-state model. The time-depe...

Recently performed experiments 1 have demonstrated that half-cycle pulses (HCPs), i.e. unimodular electromagnetic pulses, are a useful new spectroscopic tool which is particularly well suited for investigating the dynamics of weakly bound Rydberg electrons. Typically their pulse durations range from the subpicosecond to the nanosecond regime and these pulses have already been produced with elec...

This is a report about a novel experiment on double excitation of Helium by absorption of synchrotron radiation close to the double ionization threshold at 79 eV. Partial cross-sections for single-ionization from 78.15 eV up to 78,9 eV (photon energy) with an energy resolution of 3meV have been measured. The technique described in this article allows for an angular and energy resolved measureme...

A review of standard quantum mechanics, including the Pauli Exclusion Principle, as it is applied to atomic species shows that the standard theory is not consistent with energy conservation. Particular focus is given to helium in which it is shown that energy conservation is only possible if the ‘ground state’ has electrons at two distinct energies. If the two electrons in the ground state, per...

The ionization dynamics of an aminopyridine dimer (AP)(2) has been investigated by means of the direct ab initio molecular dynamics (MD) method. It was found that the reaction process was composed of three steps after the vertical ionization of (AP)(2): dimer approach, proton transfer and energy relaxation. The timescales of these processes were 50-100, 10-20, and 200 fs, respectively. The time...

An eigenchannel R-matrix expansion of the T matrix is used to calculate total integrated and ejected energy differential cross sections for the electron-impact ionization of hydrogen in the Temkin-Poet model. In previous close-coupling results, unphysical oscillations in the total ionization cross section could be averaged over due to the smooth dependence of the cross section on the incident e...

the structures and stability of 531 novel boron nitride substituted isomers of 12-crown-4 etherverified theoretically. for a collection of 23 selected bn isomers, structural geometry, vibrationalstability, energy gaps, natural bond population analysis, and nonlinear optical responses investigatedtheoretically. the changes of standard enthalpies for ionization reactions and electron affinityreac...