Bare wire anodes for electrodynamic tethers

Resumen

The collection of electrons from the ionosphere is the major problem facing high-power electrodynamic tethers.
This article discusses a simple electron-collection concept which is free of most of the physical uncertainties
associated with plasma contactors in the rarefied, magnetized environment of an orbiting tether. The idea is to
leave exposed a fraction of the tether length near its anodic end, such that, when a positive bias develops locally
with respect to the ambient plasma, and for a tether radius small compared with both thermal gyroradius and Debye length, electrons are collected in an orbital-motion-limited regime. It is shown that large currents can
be drawn in this way with only moderate voltage drops. The concept is illustrated through a discussion of performance characteristics for generators and thrusters.