Dissociative ionization of H{sub 2}{sup +} in an intense laser field: Charge-resonance-enhanced ionization, Coulomb explosion, and harmonic generation at 600 nm

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.54.3235· OSTI ID:385697

Chelkowski, S; Conjusteau, A; Zuo, T; Bandrauk, A D ^[1]

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1. Laboratoire de Chimie Theorique, Faculte des Sciences, Universite de Sherbrooke, Sherbrooke, Quebec, J1K2R1 (CANADA)

The time-dependent Schr{umlt o}dinger equation for H{sub 2}{sup +} in a 600-nm, intense ({ital I}{ge}10{sup 14} W/cm{sup 2}) laser field is solved numerically for a model which uses the exact three-body Hamiltonian with one-dimensional nuclear motion restricted to the direction of the laser electric field and three-dimensional electronic motion. High ionization rates of H{sub 2}{sup +} are found, exceeding those of neutral atomic hydrogen. This confirms, by the rigorous, full dynamical calculation, the recently discovered charge-resonance-enhanced ionization (CREI){emdash}all previous demonstrations of CREI were based on the {open_quote}{open_quote}frozen nuclei{close_quote}{close_quote} model. The numerical kinetic-energy spectra of dissociating fragments are compared with recent experimental results. They can be interpreted by a simple bond softening mechanism (or laser-induced avoided crossing in a dressed-state representation), in which the binding forces are completely suppressed by the strong electric field and thus the dissociating fragments move as free particles with a kinetic energy close to their initial vibrational energy until they reach a critical distance {ital R}={ital R}{sub {ital c}}{congruent}8 bohr, where they are rapidly ionized, due to CREI. The harmonic generation spectra calculated from our non-Born-Oppenheimer simulations show that the high harmonics are also generated when the nuclei cross this critical distance {ital R}={ital R}{sub {ital c}}. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 385697
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 4 Vol. 54; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DISSOCIATION
ELECTRIC FIELDS
HARMONIC GENERATION
HARMONICS
HYDROGEN IONS 2 PLUS
IONIZATION
KINETIC ENERGY
LASER RADIATION
PHOTON-ION COLLISIONS
VIBRATIONAL STATES