A one hundred hour test of a 100 mA class microwave discharge neutralizer was performed to investigate the erosion rate and deposition in the neutralizer. The mass loss of each component (antenna, discharge chamber wall, front yoke, back yoke, insulator and orifice) was measured in diode mode (contact voltage of 50 V) at a constant incident microwave power of 8 W and xenon mass flow rate of 49 µg/s. The measured erosion rates of the discharge chamber and the antenna were 180 µg/hr and 10 µg/hr, respectively. The element concentration of the deposited material on the back yoke and insulator were measured; the contamination on the insulator was found to contain 34% copper from the wall and 6% molybdenum from the antenna.
2016 The Japan Society for Aeronautical and Space Sciences