Surface contamination of active electrodes in plasmas: distortion of conventional Langmuir probe measurements

Journal Article · Mon Dec 01 00:00:00 EST 1975 · J. Appl. Phys., v. 46, no. 12, pp. 5134-5139

DOI:https://doi.org/10.1063/1.321572· OSTI ID:4132053

Szuszczewicz, E P; Holmes, J C

Laboratory experiments were conducted to determine the effectiveness of a newly developed pulse technique in eliminating surface contamination effects and associated hysteresis in Langmuir probe current-voltage characteristics. We found that (i) the pulse technique was superior to the conventional continuous sweep approach to Langmuir probe diagnostics; (ii) substantial potentials can develop across contaminating surface layers and that these potentials can vary in the conventional Langmuir procedure resulting in determinations of electron energies higher than actually present in the ambient plasma; and (iii) attempts to achieve ''clean-probe'' operation by heating can be of limited value. (AIP)

• Research Organization: E. O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, D. C. 20375
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-009030
• OSTI ID: 4132053
• Journal Information: J. Appl. Phys., v. 46, no. 12, pp. 5134-5139, Other Information: Orig. Receipt Date: 30-JUN-76
• Country of Publication: United States
• Language: English

Related Subjects

N70200* -Physics-Controlled Thermonuclear Research- Diagnostics
700102* -Fusion Energy-Plasma Research-Plasma Diagnostics
*PLASMA DIAGNOSTICS- PULSE TECHNIQUES
ELECTRODES
HYSTERESIS
LANGMUIR PROBE
SURFACE CONTAMINATION