Negative Ion-Sensitive Probe

A method for obtaining negative ion density and temperature is developed. A probe is biased positively against the space potential to reject positive ions. An orifice is provided in the probe surface to pass only negatively charged particles. A magnetic field behind the probe deflects electrons so that negative ions reach a collector preferentially. Current-voltage characteristics of the collector are calculated, which enables not only the design of the probe but also the accurate date analysis.