Abstract
Interferometric observation was attempted to the gas evaporation method to investigate the homogeneous nucleation and growth process of nanoparticles in vapor phase. For the first step, temperature distribution around evaporation source was measured with respect to the source temperature in the gas evaporation method for the first time in a half century. We visualized a condensation of smoke particles in gas phase and temperature history including a cooling rate of produced particles after nucleation was recognized. Homogeneously condensed WO3 nuclei initially maintain their temperature for ~5 ms and then cool down with a rate of ~5×104 K/s. The degree of supersaturation during the nucleation was at least as high as 107 .
