Outcomes of the collapse of a large bubble in water at high ambient pressures.

Presented here are observations of the outcomes of the collapses of large single bubbles in H_{2}O and D_{2}O at high ambient pressures. Experiments were carried out in a high-pressure spherical resonator at ambient pressures of up to 30 MPa and acoustic pressures up to 35 MPa. Monitoring of the collapse events and their outcomes was accomplished using multiframe high-speed photography. Among the observations to be presented are the temporal and spatial evolution of light emissions produced by the collapse events, which were observed to last on the order of 30 ns and have time independent radii on the order of 30μm; the production of Rayleigh-Taylor jets which were observed to travel distances of up to 70μm at speeds in excess of 4500 m/s; the entrainment of the light emitting regions in the jets' remnants; the production of spheroidal objects around the collapse points of the bubbles, far from any surface of the resonator; and the traversal and emergence of the Rayleigh-Taylor jets through the spherical objects. These spheroidal objects appear to behave as amorphous solids and form at locations where hydrodynamics predicts pressures in excess of the known transition pressures of water into the high-pressure crystalline ices, Ice-VI and Ice-VII.