EXPLOSIVE VAPORIZATION OF A LIQUID WATER BEAM BY IRRADIATION WITH A 10.6 MU-M INFRARED-LASER

A study was made of the explosive evaporation of a liquid beam using a 10.6 mu m infrared laser. When a liquid water beam with a diameter la rger than 50 mu m was irradiated by a 50 W infrared laser in a directi on at right angles to the liquid beam, plumes (i.e. jetlike streams), due to the explosive vaporization of the liquid, were observed from bo th the illuminated and the shadow faces of the liquid beam. When the d iameter of the liquid beam was decreased (less than or equal to 20 mu m), the generated plume became non-directional and the droplets formed became much finer. A minimum time required for the explosive vaporiza tion of the liquid,vater beam was found to be similar to 0.7 mu s for a 50 W infrared laser with a laser spot of 0.1 mm diameter, Ions forme d from a laser-irradiated aqueous solution were found to increase with increase of voltage applied to the liquid. (C) 1997 by John Wiley & S ons, Ltd.