Abstract
The authors examine qualitatively the requirement that field-particle interactions in turbulence be diffusive. The basic assumption necessary for turbulently dissipative (resonantly broadened) models is that the field-particle correlation time viewed along the particle orbit be much smaller than the field-field correlation time in the laboratory. They assume the orbit variables x(t) and v(t) are normally distribution, but the electric fields need not be. They then use simple arguments from probability theory to derive the particle propagator for a weakly turbulent plasma in a strong magnetic field. They use this propagator to find the effects of cross field diffusion on single wave pulses and plasma echoes.
Highlights
INA TURBULENT plasma, the trajectory of a charged particle is statistically described by the conditional probability distribution function, G(RVt/&V,t,)
We have considered the effect of cross field diffusion on the propagation of pulses in a plasma in the limit of a strong magnetic field
We would like to stress the ease of calculation afforded by the statistical approach of considering the fluctuating quantities as normal stochastic variables
Summary
INA TURBULENT plasma, the trajectory of a charged particle is statistically described by the conditional probability distribution function, G(RVt/&V,t,). The Vlasov equation is solved in a perturbation series, evaluating each term by the Green's function appropriate for a free particle 6 ( x - x o - uot) 6(u -uo) This essentially assumes that the zero-order trajectory for a particle is a straight line. Proceeding from the orbit statistics yields a clearer path to some standard results of weak turbulence theory-the form of D,(v),for example-and may provide a more programmatic way to carry forward other calculations, such as single pulse propagation and plasma echoes in turbulent media, and nonlinear frequency shifts (BENFORD1,976)
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