Eur. Phys. J. D 28, 193-198 (2004)
https://doi.org/10.1140/epjd/e2003-00302-7

Laser-induced control of (multichannel) intracluster reactions

The slowest is always the easiest to take

¹ Unidad de Láseres y Haces Moleculares, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Juan XXIII-1°, 28040 Madrid, Spain
² Dpto. Fisica de Materiales, Facultad de Químicas, Universidad del País, Vasco/Euskal Herriko Unibertsitatea, Centro Mixto CSIC-UPV/EHU and Donostia International Physics Center (DIPC), Apdo. 1072, 20018 San Sebastián/Donostia, Spain

Corresponding author: ^a laseres@pluri.ucm.es

Received: 3 July 2003
Published online: 2 December 2003

Abstract

An experimental and theoretical study on the excited BaFCH₃(A) photodissociation yield as a function of the excitation laser fluence is reported. Experimentally, it was found that the two-photodissociation channel yields, i.e. the reactive BaF and non-reactive Ba^* products, increased exhibiting a similar behaviour, as the laser fluence changed from 0.2 up to ca. 4 mJ/cm². Beyond this value the BaF yield levels off and the Ba^* decreases over the 4–7 mJ/cm² range. The theoretical simulation of the excited state electron-ion dynamics within the time-dependent density functional theory revealed that the reactive channel dominated the photofragmentation dynamics as it occurs within a femtosecond time scale and became accelerated as the photodissociation laser fluence increased. By contrast, the non-reactive channel only manifested for low laser fluences at the nano/picosecond time regime resulted inactive as the laser fluence increased. A simple scheme to control the dynamics of the intracluster multichannel reaction is suggested in which the slowest the channel the easiest to close it as the excitation laser power increases. Laser-modified scattering and reactions