Optical spectroscopy of transient cavitation at high pressure

The UV‐VIS spectrum of light emitted from transient cavitation events in a high‐pressure acoustic resonator is measured to determine the contents and state of matter in the plasma hot spot at the collapse. Spectra are measured for spontaneous cavitation events in water and other liquids at static pressure up to 300 bar, both degassed and with various gases dissolved in the liquid. Spectra are captured with a grating monochromator using a gated detector, or multiple detectors with bandpass filters, to partially resolve the temporal structure of the emission event. These data are used to estimate the temperature and duration of the implosion. [Work supported by SMDC Contract No. W9113M‐07‐C‐0178.]