Conical Electrostatic Probe Response in a Weakly Ionized Gas Flow.

摘要

Conical electrostatic probes of lengths 0.153, 0.393and 1.0cm were placed in partially ionized argon flows in the laboratory in order to study the use of their current-voltage characteristics in the measurement of ion number densities over a wide range. The ion densities and electron temperatures of the flows were measured with thin cylindrical electrostatic probes,and the neutral properties were determined from impact pressure,stagnation pressure and stagnation temperature measurements. The current-voltage characteristics of the ion-attracting conical probes were measured and compared to thin and thick sheath theories. Over the whole range of ion densities the measurements agreed reasonably well with the thin sheath theories of Chung and Blankenship (1966) and Denison (1967) which yield explicit expressions for the ion densities in terms of measurable quantities. (Modified author abstract)