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 130fs pulse duration laser of linear and circular polarization at 810nm, have been investigated. Coulomb explosion of C2H5OH molecule was observed to undergo a two-step process with one bond of the CCO skeleton atoms breaks firstly then the other. The similar laser intensity dependence of C2HnOH+ (n=1–4) ion yields and the molecular ion C2H5OH+ indicated that they are the results of multiphoton ionization of inner-valence electrons followed by radiationless transitions to various dissociation channels of C2H5OH+. By analyzing the momentum-scaled spectra, the intermediate daughter ions CH2OH+ and CH3+,C2H5+ and OH+ were concluded to be originated from the same Coulomb explosion channel of C2H5OH2+ ion, respectively. The atomic ion C2+ showed an anisotropic angular distribution, which is reassessed to the geometric alignment mechanism.