VELOCITY CORRELATIONS IN 2-DIMENSIONAL ELECTROSTATIC PLASMA TURBULENCE

The Eulerian and Lagrangian correlation functions in low frequency ele ctrostatic turbulence in strongly magnetized plasmas are studied in tw o spatial dimensions. In this limit the ion velocity in the direction perpendicular to a homogeneous magnetic field is approximated by the E x B/B2-velocity. For strictly flute type fluctuations a similar model is used also for the electron dynamics. Allowing, on the other hand, for a small B-parallel component of the perturbations an isothermal Bo ltzmann distribution for the electrons can be argued while the two dim ensional ion description is retained. The present analysis is based on an approximation of the actual two-dimensional flow in terms of an au tonomous flow consisting of many overlapping and mutually convecting v ortices. Simple analytical expressions for the full space-time varying Eulerian correlation are derived solely in terms of plasma parameters . It is demonstrated that an extension of the arguments giving the for egoing results allows also for derivation of analytical expressions fo r the Lagrangian correlation function. The results are supported by a Monte Carlo simulation based on the model.