Fueling limits in a cylindrical viscosity-limited reactor

TL;DR

This paper investigates the conditions under which ion viscous heating can sustain a significant ion-electron temperature difference in a rotating plasma reactor, identifying key parameters and limitations.

Contribution

It provides a steady-state analysis of the Braginskii equations for a cylindrical reactor, revealing the parameter regime for hot-ion mode and the effects of Mach number limitations.

Findings

Significant ion-electron temperature difference occurs at $ ho_i extgreater{}0.1R$.

Analytic solutions are derived for low flow regimes.

Numerical analysis shows limitations at Mach numbers around 2.

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 $\rho_i\gtrsim0.1R$. An analytic, leading order low flow solution is obtained, and a numerical, moderate Mach number $M\lesssim2$ is investigated. The limitation is found to be at moderate Mach numbers.