Femtosecond laser-induced dissociative ionization and Coulomb explosion of ethanol

Using time-of-flight mass spectrometer, the femtosecond laser-induced dissociative ionization and Coulomb explosion of ethanol under irradiation of 130 fs pulse duration laser of linear and circular polarization at 810 nm, have been investigated. Coulomb explosion of C2H5OH molecule was observed to undergo a two-step process with one bond of the C-C-O skeleton atoms breaks firstly then the other. The similar laser intensity dependence of C2HnOH+ (n = 1-4) ion yields and the molecular ion C2H5OHdivided by indicated that they are the results of multiphoton ionization of inner-valence electrons followed by radiationless transitions to various dissociation channels of C2H5OHdivided by. By analyzing the momentum-scaled spectra, the intermediate daughter ions CH2OH+ and CHT3divided by, C2H5divided by and OHdivided by were concluded to be originated from the same Coulomb explosion channel of C2H5OH2+ ion, respectively. The atom ic ion C-2divided by showed an anisotropic angular distribution, which is reassessed to the geometric alignment mechanism. (C) 2004 Elsevier B.V. All rights reserved.