NUCLEATION IN SUPERSATURATED HE-3-HE-4 LIQUID-MIXTURES - DECAY OF METASTABLE STATES AT ULTRALOW TEMPERATURES

In order to investigate the possibility of observing the crossover of the nucleation process from the classical to the quantum regime, the decomposition of supersaturated He-3-He-4 mixtures in the dilute phase has been studied in the temperature range from 160 mK down to 400 muK. The observed amount of critical supersaturation becomes almost independent of temperature below about 10 mK. while it increases with temperature above about 10 mK. The data are analyzed with the recent theory of Burmistrov, Dubovskii and Tsymbalenko. The results indicate a crossover temperature around 70 mK and the existence of the effect of dissipation.