Charles, C.Boswell, R. W.Lieberman, M. A.2015-11-082015-11-080003-6951http://hdl.handle.net/1885/16401A 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 measuredbeamvelocity is about 6kms⁻¹, the beam area is about 150cm², and the measuredbeam divergence is less than 6°.http://www.sherpa.ac.uk/romeo/issn/0003-6951..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 9/11/15). Copyright 2006 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters and may be found at https://doi.org/10.1063/1.2426881Keywords: Divergence; Electrostatic ion energy analyzer; Helicon double layer thruster; Potential drop; Gases; Helicons; Magnetic field effects; Positive ions; Pressure effects; Xenon; Ion beamsXenon ion beam characterization in a helicon double layer thruster2006-12-2910.1063/1.24268812015-12-08