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Recent experiments have investigated the dissociative ionization of NaI and CsI, each aggregated with a molecule of acetonitrile CH[sub 3]CN, using two femtosecond laser pulses. The first, the pump pulse, excites the NaI or CsI diatom to a dissociative state. The second, the probe pulse, then ionizes the sodium or cesium atom after a variable delay time, and the resulting ion is detected. In the case of NaI, the ion signal is characterized by a single maximum. For CsI, however, an oscillatory signal is observed. By performing two-dimensional wave packet propagations, we are able to reproduce this behavior, which can be explained using simple physical arguments. [ABSTRACT FROM AUTHOR]

Using a wave packet simulation on simplified potential curves, we investigate the vibrational dynamics of NaI in its first excited electronic state, both isolated and aggregated with a molecule of acetonitrile. The probe signal is obtained by resonant multiphoton ionization (REMPI) of the diatomic chromophore NaI via Rydberg states. The addition of acetonitrile is found to change greatly the ionization signal, suggesting strong modification of the reaction dynamics. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Fragmentation dynamics of the molecular ion Na+2 irradiated by an intense femtosecond pulse laser is studied using quantum wave packet propagations. It is demonstrated that the pulse duration (20–250 fs) can be used as a control parameter for both the total dissociation probability and the branching ratio between different dissociation channels. This pulse length effect is important when the duration of the pulse is shorter than the vibrational period of the molecular ion in the ground state. The effects of laser intensity (1011–3×1012 W/cm2), wavelength (680–780 nm) and initial vibrational level on the dissociation dynamics are also studied. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Examines the femtosecond dynamics of sodium iodide (NAI) ionization and dissociative ionization. Effects of kinetic energy on the natural broadening of probability distribution; Dependence of the photoelectron spectrum of NAI molecule on the pump-probe delay time; Impact of the small transition dipole on the small range signal.