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 larger than 50 mu m was irradiated by a 50 W infrared laser in a direction at right angles to the liquid beam, plumes (i.e. jetlike streams), due to the explosive vaporization of the liquid, were observed from both the illuminated and the shadow faces of the liquid beam. When the diameter 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 vaporization 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 formed from a laser-irradiated aqueous solution were found to increase with increase of voltage applied to the liquid. (C) 1997 by John Wiley & Sons, Ltd.