| AVS 58th Annual International Symposium and Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS2-TuA |
| Session: | Plasma Diagnostics, Sensors and Control I |
| Presenter: | J.P. Sheehan, University of Wisconsin-Madison |
| Authors: | J.P. Sheehan, University of Wisconsin-Madison Y. Raitses, Princeton Plasma Physics Laboratory N. Hershkowitz, University of Wisconsin-Madison I. Kaganovich, Princeton Plasma Physics Laboratory N.J. Fisch, Princeton Plasma Physics Laboratory |
| Correspondent: | Click to Email |
Accurate measurements of the plasma potential is a critical challenge especially for complex plasmas such as magnetized and flowing. We compare various emissive probe techniques for measurements of the plasma potential. The measurements were conducted in a low-pressure magnetized discharge of the Hall thruster. The thruster was operated with xenon gas in subkilowatt power range and the discharge voltage range of 200-450 V. The probe was placed at the channel exit where, the electron temperature is in the range of 10 to 60 eV and the plasma potential is in the range of 50 to 250 V. The floating point method is expected to give a value ~Te/e below the plasma potential. The experimental results are consistent with these expectations. Specifically, it is shown that the floating potential of the emissive probe is ~2Te/e below the plasma potential. It is observed that the separation technique varies wildly and does not give a good measure of the plasma potential.
This work was supported by US Department of Energy grants No. DE-AC02-09CH11466, No. DE-FG02-97ER54437, and No. 3001346357 and the Fusion Energy Sciences Fellowship Program administered by Oak Ridge Institute for Science and Education under a contract between the U.S. Department of Energy and the Oak Ridge Associated Universities.