Ejection mechanism of molecules and neutral clusters from liquid beam under irradiation of IR laser

Resorcinol molecules and those solvated with solvent water molecules were i solated in the gas phase from a liquid beam of an aqueous solution of resor cinol by resonant vibrational excitation of solvent water molecules under I R-laser irradiation. The spatial distribution of the ejected species at var ious delay times from the IR-laser irradiation indicates that two different isolation mechanisms operate: One dominates in a time range shorter than s imilar to 1 mu s (early-time domain), and the other in a time range longer than similar to 1 ys (late-time domain). A time-dependent measurement of th e liquid-beam profile by optical diffraction shows that the beam has a smoo th surface in the early-time domain, whereas in the late-time domain the su rface roughness overweighs the wavelength of the illumination laser. (C) 20 00 Elsevier Science B.V. All rights reserved.