Plasma coupling of microwave neutralizer

A microwave neutralizer was developed in Institute of Space and Astronautical Science. Three types of the microwave neutralizer were febricated and their operational characteristics were measured. A prototype neutralizer exhibited stalbe operation at low microwave power of 2W. A higher power operation was investigated using a short type neutralizer and showed a high electron current of over 500 mA. Plasma properties in the discharge chamber of the neutralizer were measured using Langmuir probe and a microwave connector called bias-T. Dense plasma over the cutoff density of 2.2xlO cm" was observed at the electron extraction orifice.