The interaction of an intense laser field with a beam of atomic ions has been investigated experimentally for the first time. The ionization dynamics of Ar+ ions and Ar neutrals in a 60 fs, 790 nm laser pulse have been compared and contrasted at intensities up to 10(16) W cm-2. Our results show that nonsequential ionization from an Ar+ target is strongly suppressed compared with that from the c...

Ionization rates of molecules have been modeled with time-dependent configuration interaction simulations using atom centered basis sets and a complex absorbing potential. The simulations agree with accurate grid-based calculations for the ionization of hydrogen atom as a function of field strength and for charge resonance enhanced ionization of H2(+) as the bond is elongated. Unlike grid-based...

We study strong field double ionization of a series of organic molecules by making use of coincidence detection of fragment ions. We measure the double ionization yield as a function of pulse duration, intensity, polarization, and molecular conjugation. For conjugated molecules we find strong enhancement in the double ionization rate over what one would expect on the basis of tunneling or multi...

We propose an empirical formula for the static field ionization rates of atoms and molecules by extending the well-known analytical tunnelling ionization rates to the barrier-suppression regime. The validity of this formula is checked against ionization rates calculated from solving the Schrödinger equation for a number of atoms and ions. The empirical formula retains the simplicity of the orig...

We report a numerical study of strong-field ionization rates of the H2 molecule using time-dependent densityfunctional theory (TDDFT). In the dc field limit, TDDFT results for the rate of tunneling ionization agree with molecular Ammosov-Delone-Kralnov (MO-ADK) predictions, as well as results from a complex scaling method at the full configuration interaction level. Our study demonstrates the e...

This Letter reports a modeling study on the formation of streamer discharges from an isolated ionization column under subbreakdown condition. Numerical simulations show that positive streamers are able to form from the tip of an ionization column in a uniform applied electric field well below the breakdown threshold field. However, even when the applied field approaches the breakdown threshold ...

In this paper, we present a model for propagation of intense and ultrashort laser pulses ionizing dielectrics. We consider early ionization so that this process is sufficiently weak to avoid requiring a complete description of the ionization process (e.g. the use of kinetic equations which are very expensive from a computational point of view). As the intensity of the field is small, one photon...