Fluctuations with $1/f$ Spectrum under Conditions of Acoustic Cavitation of Water

The results are given of an experimental investigation of fluctuations under conditions of cavitation of water in an ultrasonic field. The laser photometry and resistive methods are employed. The fluctuations of the intensity of transmitted laser radiation and the fluctuations of electrical conductivity during the passage of electric current through a weak aqueous electrolyte under conditions of ultrasonic cavitation are measured in the experiments. A mode is found which is characterized by the $1/f$-behavior of power spectra and by the bimodal function of local distribution of fluctuation amplitudes. The distribution function under conditions of scale roughening of realizations is investigated. It is found that an increase in the region being probed leads to scale-invariant Gaussian distributions; this agrees with the theoretical concepts of the generation of $1/f$ fluctuations in the case of nonequilibrium phase transitions.