Laser-filament-induced condensation in an inverted cloud chamber

Abstract

We have demonstrated experimentally that firing a laser filament in a subsaturated zone of a cloud chamber of inversed temperature profile could induce water condensation. Initially, through ion chromatography performed on samples collected from a receptacle placed under the laser, the presence of HNO3 was observed. The existence of this HNO3, as well as digital camera images of very tiny droplets close to the laser axis viewed at an angle perpendicular to the chamber, suggest that the condensation could be due to the laser. A second experiment measuring the growth of the water droplets using a cooled receptacle confirmed the existence of laser-induced condensation in these conditions.