Xenon ion beam characterization in a helicon double layer thruster

Abstract

A current-free electric double layer is created in a helicon double layer thruster operating with xenon and compared to a recently developed theory. The ${\mathrm{Xe}}^{+}$ ion beam formed by acceleration through the potential drop of the double layer is characterized radially using an electrostatic ion energy analyzer. For operating conditions of $500\mathrm{W}$ rf power, $0.07\mathrm{mTorr}$ gas pressure, and a maximum magnetic field of $125\mathrm{G}$ , the measured beam velocity is about $6\mathrm{km}{\mathrm{s}}^{-1}$ , the beam area is about $150{\mathrm{cm}}^2$ , and the measured beam divergence is less than 6°.