Xenon ion beam characterization in a helicon double layer thruster

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 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 500W rf power, 0.07mTorr gas pressure, and a maximum magnetic field of 125G, the measured beam velocity is about 6kms−1, the beam area is about 150cm2, and the measured beam divergence is less than 6°.