Experiments of asymmetry-induced particle transport in magnetized, pure electron plasma columns

xperiments are presented on asymmetry-induced particle transport in a magnetized, pure electron plasma confined in a cylindrical trap. This transport appears as the diffusive-like expansion of the plasma column across magnetic field lines, and is generic to many neutral and nonneutral plasma devices. Measurements of transport induced by 3 different types of asymmetry are presented.;Definitive measurements characterize the "rotational pumping" of a plasma column which is displaced from the trap axis. Rotational pumping is the collisional dissipation of the axial compressions caused by E ;The rotational pumping rate is proportional to the collisional temperature equipartition rate, which drops precipitously in the cryogenic, strongly magnetized regime; surprisingly, the transport rate is otherwise independent of magnetic field. The observed rates are in close agreement with a new theory by Crooks and O'Neil. The unusual temperature dependence of the transport explains previously observed "sawtooth" oscillations of the plasma displacement.;The m = 1 diocotron mode can also be damped by a "squeeze" perturbation, which is a static voltage applied to half the length of the trap. The measured dependence of the damping rate with temperature, density, and plasma radius is similar to that observed for rotational pumping. However, the Crooks and O'Neil theory predicts that the squeeze perturbation should decrease the damping rate, in contradiction with the observed increase. Furthermore, the measured rates are not suppressed by strong magnetization as are the rotational pumping rates.;Small, azimuthal asymmetries inherent in the trap cause "anomalous" transport even in on-axis plasmas. When the E...