An origin of 1/f fluctuations at a nonequilibrium phase transition

We present the results of experimental study of an intensive source of wide -band 1/f noise whose generation appears in a system of two interacting non equilibrium phase transitions. Such a process has been realized in the regi on of superposition of a superconductor-normal conductor phase transition o n a liquid-vapor crisis transition in a boiling cooler. A mathematical mode l describing phase transitions in a dynamical system with two interacting o rder parameters, converting "white" noise into two stationary stochastic pr ocesses with 1/f and 1/f(2) spectra has been suggested. The properties of m odel oscillations with 1/f spectrum are qualitatively adequate to those obs erved in experiment. The characteristic difference of model oscillations wi th a 1/f(2) spectrum from classic random walks has also been noted. (C) 199 9 Elsevier Science B.V. All rights reserved.