Acoustic measurements of the nucleus size distribution at the cavitation threshold

TL;DR

This paper investigates the size distribution of nuclei responsible for acoustic cavitation at the threshold, combining experimental and numerical methods to better understand and control cavitation in medical ultrasound applications.

Contribution

It introduces novel acoustic nucleation techniques and models to reconcile discrepancies between measurements and classical theories of cavitation thresholds.

Findings

Identified a reproducible subtype of heterogeneous cavitation.

Characterized the nucleus size distribution at cavitation threshold.

Provided insights for improved cavitation control methods.

Abstract

Understanding the acoustic cavitation threshold is essential for minimizing cavitation bioeffects in diagnostic ultrasound and for controlling cavitation--mediated tissue ablation in focused ultrasound procedures. The homogeneous cavitation threshold is an intrinsic material property of recognized importance to a variety of applications requiring cavitation control. However, acoustic measurements of the cavitation threshold in water differ from those predicted by classical nucleation theories. This persistent discrepancy is explained by combining novel methods for acoustically nucleating single bubbles at threshold with numerical modeling to obtain a nucleus size distribution consistent with first--principles estimates for ion--stabilized nucleii. We identify acoustic cavitation at threshold as a reproducible subtype of heterogeneous cavitation with a characteristic nucleus size distribution. Knowledge of the nucleus size distribution could inspire new approaches for achieving cavitation control in water, tissue, and a variety of other media.