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
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
PACS: 36.40.Jn – Reactivity of clusters / 36.40.Qv – Stability and fragmentation of clusters / – 34.50.Rk
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004