Related papers: ATI as a source for multiply charged ion productio…
We introduce a unified and simplified theory of atomic double ionization. Our results show that at high laser intensities ($I \ge 10^{14}$ watts/cm$^2$) purely classical correlation is strong enough to account for all of the main features…
Ionization-excitation of an atom induced by the absorption of a single photon in the presence of a neighbouring atom is studied. The latter is, first, resonantly photoexcited and, afterwards, transfers the excitation energy radiationlessly…
In the past three decades, the development of nuclear physics facilities for fundamental and applied science purposes has required an increasing current of multicharged ion beams. Multiple ionization implies the formation of dense and…
The theoretical community has found interest in the ability of a two-level atom to generate a strong many-body interaction with light under pulsed excitation. Single-photon generation is the most well-known effect, where a short Gaussian…
We theoretically study multiphoton ionization of the Ca atom irradiated by the second (photon energy 3.1 eV) and third (photon energy 4.65 eV) harmonics of Ti:sapphire laser pulses (photon energy 1.55 eV). Because of the dense energy level…
Electron-impact ionization of an atom or ion in the presence of a neighboring atom is studied. The latter is first collisionally excited by the incident electron, whose energy is assumed to be high but nonrelativistic. Afterwards, the…
An analytical model of a single-atom electron source is presented, where electrons are created by near-threshold photoionization of an isolated atom. The model considers the classical dynamics of the electron just after the photon…
Ionization, excitation, and de-excitation to the ground state is studied theoretically for the first excited singlet state B $^1\Sigma_u^+$ of H$_2$ exposed to intense laser fields with photon energies in between about 3 eV and 13 eV. A…
The spontaneous emission of an excited two-level emitter driven by a strong classical coherent low-frequency electromagnetic field is investigated. We find that for relatively strong laser driving, multi-photon processes are induced,…
Using a three-dimensional semiclassical method, we theoretically investigate frustrated double ionization (FDI) of Ar atoms subjected to strong laser fields. The double-hump photoelectron momentum distribution generated from FDI observed in…
Based on the frequency-domain theory, we investigate the above-threshold ionization (ATI) process of an atom in a two-color laser field with infrared (IR) and extreme ultraviolet (XUV) frequencies, where the photon energy of the XUV laser…
Nonsequential multiple ionization of atoms in intense laser fields is initiated by a recollision between an electron, freed by tunneling, and its parent ion. Following recollision, the initial electron shares its energy with several bound…
A strong laser field and the Coulomb field of a nucleus can produce e^{+}e^{-} pairs. It is shown for the first time that there is a large probability that electrons and positrons created in this process collide after one or several…
Resonance-enhanced multiphoton ionization (REMPI) in potassium atom is investigated within the strong coupling regime using photoelectron momentum imaging techniques. The kinetic energy distribution of the ionized electrons reveals the…
Theoretical study on H$_2^+$ in an intense infrared laser field on the attosecond time-scale reveals that the molecular ion shows multiple bursts of ionization within a half-cycle of the laser field oscillation, in contrast to the widely…
A second plateau in the harmonic spectra of laser-driven two-electron atoms is observed both in the numerical solution of a low-dimensional model helium atom and using an extended strong field approximation. It is shown that the harmonics…
We demonstrate kinematically complete measurements on frustrated double ionization of argon atoms in strong laser fields with a reaction microscope. We found that the electron trapping probability after strong field double ionization is…
Modern intense ultrafast pulsed lasers generate an electric field of sufficient strength to permit tunnel ionization of the valence electrons in atoms. This process is usually treated as a rapid succession of isolated events, in which the…
We present a theoretical analysis of high-order harmonic generation from ion-atom collisions in the presence of linearly polarized intense laser pulses. Photons with frequencies significantly higher than in standard atomic high-harmonic…
We present a theory illuminating the cross-over from strong-field tunnelling ionization to weak-field multiphoton ionization in the interaction of a classical laser field with a hydrogen atom. A simple formula is derived in which the…