Full diagnostics of an inductive plasma section of an ion thruster

Inductive low pressure xenon plasma was generated in an input section of an ion thruster. Its full diagnostics consisted of integral property measurements (Patented) and local plasma parameter determination. Accurate local diagnostics disclosed plasma parameter distributions using cylindrical Langmuir probes. Their leads were protected by conventional bare shields. Subsequent analysis showed that they distorted xenon plasma lowering all its parameters. Then probe diagnostics was specifically arranged with radially movable straight probe-1 and the additional L-shaped probe-2. They both operated in one special position: shield-1 was absent and shield-2 was non-zero disclosing measurement errors which helped to correct probe-1's data. As the result three new probe applications have been proposed: a) elimination of bare probe protective shield's influence on measurement results (Pat. Applic-n); b) measurements of the probe sheath thicknesses and the mean ion mass using cylindrical probes in Maxwellian plasmas (Patented); c) evaluation of ion current density distributions to an ion extracting electrode of an ion thruster arranged by the plane by-wall probe simulator (Pat. Applic-n).