Submitted for the DAMOP13 Meeting of The American Physical Society Mechanism of delayed double ionization in a strong laser field TURGAY UZER, Georgia Institute of Technology, FRANCOIS MAUGER, Universite de Sherbrooke, ADAM KAMOR, Georgia Institute of Technology, CRISTEL CHANDRE, Centre de Physique Theorique — Nonsequential Double Ionization (NSDI), for linearly polarized strong laser fields, h...

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 ...

In a magnetized inhomogeneous warm plasma having ionization/recombination, usual version of the KdV equation is found to be modified by two additional terms arising due to the inclusion of ionization/recombination and the density gradient in the plasma. The density gradient in the plasma shows its dependence on the ionization/recombination rate, ion-to-electron temperature ratio, obliqueness of...

We report the first observation of ionization of Rydberg atoms by subpicosecond, circularly polarized THz radiation. The field amplitude in these pulses is non-negligible for only one-quarter of an optical cycle. The experiment is performed in the short-pulse regime, where the duration of the ionizing pulse is shorter than the classical Kepler period of the Rydberg electron. We find that the io...

We numerically investigate multiphoton ionization of excited hydrogen atoms in magnetic and microwave fields when up to NI = 600 photons are required for ionization. The analytical estimates for the quantum localization length in the classically chaotic regime are in agreement with numerical data. The excitation is much stronger as compared to the case with microwave field only due to the chaot...

A strongly saturated waveguide-based optical-field-ionization soft-x-ray laser seeded by high harmonic generation was demonstrated for Ni-like Kr lasing at 32.8 nm. Compared with the same laser seeded only with spontaneous emission, seeding with high harmonics yields much smaller divergence, enhanced spatial coherence, and controlled polarization. The integration of high harmonic seeding, optic...

Electric fields of repetitively pulsed nanosecond discharges have been measured from electric-field induced Raman scattering by hydrogen molecules. Especially the temporal evolution of the electric field spatial distribution was recorded. With a high-speed optical emission intensity analysis, it has been found that most ionization events take place within a very short period during an ionizatio...

We report a novel experimental technique for the comparison of ionization processes in ultrafast laser pulses irrespective of pulse ellipticity. Multiple ionization of xenon by 50 fs 790 nm, linearly and circularly polarized laser pulses is observed over the intensity range 10 TW/cm to 10 PW/cm using Effective Intensity Matching (EIM), which is coupled with Intensity Selective Scanning (ISS) to...

We discuss the method of field strength calibration from energy distributions measurements of free space field ionization. An alternative approach is considered and an improved calibration is suggested. The method of electric field strength calibration from considerations of energy distribution of field ionization in free space above a field ion emitter tip is due to Sakurai and Muller [1,2]. U...

Intense, 100 fs laser pulses at 3.2 and 3.6 μm are used to generate, by multiphoton ionization, broadband wave packets with up to 400 eV of kinetic energy and charge states up to Xe(+6). The multiple ionization pathways are well described by a white electron wave packet and field-free inelastic cross sections, averaged over the intensity-dependent energy distribution for (e, ne) electron impact...