Observation of a Jump Like Transition from Fast to Normal Kinetics of Facets for Free Growing Helium Crystals

TL;DR

This study investigates the growth kinetics of free helium crystals at very low temperatures, revealing a sudden transition from fast to normal facet growth within microseconds, indicating complex underlying phase change dynamics.

Contribution

It reports the first observation of a jump-like transition in helium crystal facet growth kinetics, advancing understanding of phase change behaviors at ultra-low temperatures.

Findings

Discovered a jump-like transition in growth kinetics within 80 microseconds.

Observed drastic changes in facet growth modes at supersaturations above 0.5 mbar.

Identified anomalous high growth rates preceding normal growth phases.

Abstract

The growth kinetics is studied of free-growing helium crystals within the temperature range 0.5-0.83 K and supersaturations to 10 mbar. For the pressure supersaturations above 0.5 mbar, numerous drastic changes are observed in the growth kinetics for all crystalline facets from the normal and slow kinetics to the anomalously high or burst-like one. It is found for the first time that the anomalous to normal transition in the facet growth kinetics occurs in a jump like manner within a time 80 {\mu}s interval of the measurement record.