Emissive probe current in response to time-varying probe bias voltage

POSTER

Abstract

Applications of biased emissive probes for measurements of the plasma potential [1] require an understanding of the dynamic response of the probe current to time-variations of the sweeping probe bias voltage. In this work, we explore fundamental and technical limitations of emissive probe measurements with a changing bias voltage at timescales both slower and faster than the inverse of the ion plasma frequency. The focus is on measurements of the time-evolution of the probe current as the sheath between the plasma and a strongly emitting probe restructures in response to the bias change. A comparison of experimental results with simulations [2] will be discussed.

[1] J. P. Sheehan, Y. Raitses, N. Hershkowitz, I. Kaganovich, and N. J. Fisch, Physics of Plasmas 18, 073501 (2011).

[2] G. R. Johnson and M. D. Campanell, Plasma Sources Sci. Technol. 30, 015003 (2021)

*This work is supported by the Princeton Collaborative Research Facility (PCRF), which is supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-09CH11466 and U.S. DOE grant. Campanell’s contributions were performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

Presenters

  • Emma Devin

    • Princeton Plasma Physics Laboratory

Authors

  • Emma Devin

    • Princeton Plasma Physics Laboratory

  • Yevgeny Raitses

    • US Dept of Energy-Germantown
    • Princeton Plasma Physics Laboratory
    • Princeton Plasma Physics Laboratory, Princeton, NJ 08540
    • Princeton Plasma Physics Laboratory, Princeton University

  • Michael Campanell

    • Lawrence Livermore National Laboratory
    • Lawrence Livermore Natl Lab