Negative Pressures and Spallation in Water Drops Subjected to Nanosecond Shock Waves

Most experimental
studies of cavitation in liquid water at negative
pressures reported cavitation at tensions significantly smaller than
those expected for homogeneous nucleation, suggesting that achievable
tensions are limited by heterogeneous cavitation. We generated tension
pulses with nanosecond rise times in water by reflecting cylindrical
shock waves, produced by X-ray laser pulses, at the internal surface
of drops of water. Depending on the X-ray pulse energy, a range of
cavitation phenomena occurred, including the rupture and detachment,
or spallation, of thin liquid layers at the surface of the drop. When
spallation occurred, we evaluated that negative pressures below −100
MPa were reached in the drops. We model the negative pressures from
shock reflection experiments using a nucleation-and-growth model that
explains how rapid decompression could outrun heterogeneous cavitation
in water, and enable the study of stretched water close to homogeneous
cavitation pressures.