Abstract |
Homogeneous condensation is a first occurring process to obtain solid materials around evolved stars. Since there is no or very few heterogeneous nucleation site, solid materials must condense by themselves homogeneously. However, there is no data that how large supersaturation is required for the condensation. To investigate the homogeneous nucleation and growth process of cosmic dust, interferometric observation was attempted for the fist time to the gas evaporation method in laboratory. In preliminary experiment, we found the degree of supersaturation for nucleation was extremely high, 10^6-10^7, which was determined from the interferogram. Surface free energy, sticking probability and growth velocity can also be deduced from the calculated values by the semi-phenomenological nucleation theory. |