Fueling limits in a cylindrical viscosity-limited reactor

Abstract

Recently, a method to achieve a "natural hot-ion mode" was suggested, by utilizing ion viscous heating in a rotating plasma with a fixed boundary. We explore the steady-state solution to the Braginskii equations and find the parameter regime in which a significant temperature difference between ions and electrons can be sustained in a driven steady state. The threshold for this effect occurs at ρ i 0.1R. An analytic, leading order low flow solution is obtained, and a numerical, moderate Mach number M 2 is investigated. The limitation is found to be at moderate Mach numbers. I. INTRODUCTIONMagnetic plasma confinement assisted by rotation has been explored in several configurations, such as mirrors [1-3] and toroidal devices [4,5]. Rotating mirrors in particular are receiving renewed interest, leading to new experimental devices in the near future [6][7][8].Plasma mass filters[9-17] are another rotating plasma application in which density gradients are of particular importance, and are similar to rotating mirrors in many respects.Sufficiently long mirrors may be analyzed using classical transport theory. Radial cross field ion currents [18,19] in such devices appear to be an attractive fueling method, as they