Two-dimensional bounce-averaged collisional particle transport in a single species non-neutral plasma

In this paper we describe a new theory of like particle collisional transport for a non-neutral plasma confined in a Penning trap. The theory is valid in the regime omega(b) > omega(E), omega(b) > nu(c), and r(c) < lambda(D) where Wb is the axial bounce frequency, omega(E) is the ExB rotation frequency, nu(c) is the collision frequency, r(c) is the cyclotron radius, and lambda(D) is the Debye length. In this regime each particle can be bounce averaged into a long rod and the transport understood as arising from the ExB drift motion of the rods due to long-range mutual interactions. This is a very different mechanism than is considered in the classical theory of transport, where a particle guiding center undergoes a step of order r(c) as a result of a velocity scattering collision. For the parameter range considered, the new theory predicts transport rates that are orders of magnitude larger than those predicted by classical theory and that scale with magnetic field strength like 1/B rather than 1/B-4. The new theory differs from a previous analysis of transport due to ExB drift interactions of charged rods, in that the finite length of the rods is taken into account. This enables transport to occur even for the case of an ExB drift rotation frequency that is a monotonic decreasing function of radius las was the case in recent experiments). (C) 1998 American Institute of Physics.