Investigation of erosion and deposition in a microwave discharge neutralizer

Abstract

A one hundred hour test of a 100mA 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 8W 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.