Ultrasonic self-focusing and self-transparency in the liquid

Abstract
Process of thermal self -action of powerful ultrasonic signals in viscous liquids are theoretically and experimentally investigated. Simultaneous realization of acoustic beam self-focusing and sound induced self-transparency of liquid gives a new nonlinear effect of high energy wave packet self-concentration. A pulse with duration Δt ≈ 10s is formed inside the liquid, the intensity of ultrasound in its peak is several times greater than the input level. The parameters of this process are calculated, which are in a good agreement with experimental data.