Plasma Diagnostics of Microwave Neutralizer.

A microwave neutralizer was developed in Institute of Space and Astronautical Science. Plasma properties in the discharge chamber of the neutralizer were measured using Langmuir probe and a microwave connector called bias-T. A dense plasma over the cut off density of 2.2×1011cm-3 was observed at the electron extraction orifice. To investigate the endurance problem, an erosion rate was measured using three types of microwave neutralizer, changing the magnetic field strength and chamber length as parameters.