Onset of symmetric plasma turbulence

We analyze the electrostatic turbulence in a stationary toroidal magnetoplasma, created by radio-frequency waves, and confined by a toroidal magnetic field. The increase of toroidal magnetic field, leads tol gradients, in the mean plasma radial profiles and to the enhancement of electrostatic turbulence. Another consequence is the emergence of symmetry in the probability distributions of fluctuations and of the time in which they return to a specified reference interval of values. This symmetry as well as scaling laws reported here are typically observed in low-dimensional chaotic dynamical systems. Decreasing the magnetic field breaks the symmetry in the probability distribution; however, it preserves the correlation properties of a few average quantities. (C) 2001 Elsevier Science B.V. All rights reserved.