Cylindrical Langmuir probe measurements in an ion thruster plume

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:163101

Semak, V V; Keefer, D ^[1]

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1. Univ. of Tennessee Space Inst., Tullahoma, TN (United States). Center for Laser Applications

Cylindrical Langmuir probe measurements have been made in the exhaust plume of a 15 cm diameter three-grid ion thruster. Xenon gas was used as a propellant. The experiments were performed in a large vacuum chamber with background pressure values of 2 {times} 10{sup {minus}4} Torr and 3 {times} 10{sup {minus}6} Torr. A 250 {micro}m diameter tungsten probe 2.78 mm long was used in the experiments. The data collected for radial and axial scans were analyzed to provide measurements of electron temperature, plasma potential and electron density. It was found that, unlike the case of a stationary plasma, the electron saturation current is only several times higher than ion current. Small errors in the determination of the ion current component of the characteristic curve can result in significant overestimation of electron temperature. A method of data analysis was developed which includes an estimation of the collected ion current. This method is compared with a numerical particle simulation model for calculation of the ion current component.

• OSTI ID: 163101
• Report Number(s): CONF-950612--; ISBN 0-7803-2669-5
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
COMPARATIVE EVALUATIONS
DATA ANALYSIS
ELECTRON DENSITY
ELECTRON TEMPERATURE
EXHAUST GASES
ION THRUSTERS
LANGMUIR PROBE
PLASMA DIAGNOSTICS
PLASMA POTENTIAL
PROPULSION SYSTEMS