Non-Maxwellian Free-Energy Generation in the Magnetotail due to Chaotic Particle Motion.

Abstract : It has previously been shown that the charged-particle motion in a magnetotail-like magnetic field is generally non-integrable and that the particle orbits can be classified into three distinct types; the bounded integrable orbits, unbounded stochastic orbits and unbounded transient orbits. The three distinct types of orbits occupy disjoint regions of the phase space. As a result, the different regions of the phase space retain the memory of the existing distribution function for different lengths of time. The concept of differential memory in single-particle distributions is discussed. Physical implications for the dynamical properties of the magnetotail plasmas, and the possible generation of non-Maxwellian features in the distribution function are discussed. Keywords: Stochasticity; Magnetosphere; and Chaos.