The Chaos Control in Parametric Decay Instability of Stimulated Backscattering by a Pump Frequency Modulation

Over the past decade, the problem of chaos controlling in plasmas attracted significant attention due to the importance of this topic for many processes in plasma physics [1-3]. In addition to the general interest of this subject the studies were motivated by the possibility of reduction of the anomalous transport, associated with plasma turbulent phenomena. It is well known that almost all systems reach turbulent state via chaos development, therefore, investigation of chaos control may contribute to understanding and control of the turbulence in plasma processes. The main idea in controlling chaos is to use the high sensitivity of the system to small perturbations to change the dynamical state. Based on this approach, several effective methods of chaos control have been proposed by Ott, Grebogi, and Yorke (OGY) [4] and Paragas (TDAS) [5]. In this paper we demonstrate experimentally the possibility of three-wave system transition from chaotic to regular behavior under influence of the pump frequency modulation without directly using the well-known OGY and TDAS methods. We perform studies using the wave system in magnetized inhomogeneous plasma in which absolute decay parametric instability of stimulated backscattering l → l’ + s is excited at linear stage [6].