Rikard Bodin '20
Neng Yin '20
We report experiments conducted in an expanding argon plasma generated in the inductive mode of a helicon source in the Hot hELIcon eXperiment–Large Experiment on Instabilities and Anisotropies facility. As the neutral gas pressure increases, the supersonic ion acceleration weakens. Increasing neutral pressure also alters the radial profile of electron temperature, density, and plasma potential upstream of the plasma expansion region. Langmuir probe measurements of the electron energy probability function (EEPF) show that heating of electrons at the plasma edge by RF fields diminishes with increasing gas pressure, yielding a plasma with a centrally peaked electron temperature, and flat potential profiles at higher neutral pressures. For neutral pressures at which ion acceleration regions develop in the expanding plasma plume, EEPFs reveal electrons with two temperature components.
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Version of Record
Aguirre, E. M., R. Bodin, N. Yin, T. N. Good, and E. E. Scime. “Evidence for Electron Energization Accompanying Spontaneous Formation of Ion Acceleration Regions in Expanding Plasmas.” Physics of Plasmas 27, no. 12 (2020).
Required Publisher's Statement
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Aguirre, E. M., R. Bodin, N. Yin, T. N. Good, and E. E. Scime. “Evidence for Electron Energization Accompanying Spontaneous Formation of Ion Acceleration Regions in Expanding Plasmas.” Physics of Plasmas 27, no. 12 (December 1, 2020): 123501. and may be found at https://doi.org/10.1063/5.0025523.