Probe measurements of electric field and electron density fluctuations at megahertz frequencies using in-shaft miniature circuits

Yoo, Jongsoo ; Hu, Yi-Bo ; Ji, Hantao ; Goodman, Aaron ; Wu, Xuemei
Issue date: 2021
Rights:
Creative Commons Attribution 4.0 International (CC BY)
Cite as:
Yoo, Jongsoo, Hu, Yi-Bo, Ji, Hantao, Goodman, Aaron, & Wu, Xuemei. (2021). Probe measurements of electric field and electron density fluctuations at megahertz frequencies using in-shaft miniature circuits [Data set]. Princeton Plasma Physics Laboratory, Princeton University. https://doi.org/10.11578/1814954
@electronic{yoo_jongsoo_2021,
  author      = {Yoo, Jongsoo and
                Hu, Yi-Bo and
                Ji, Hantao and
                Goodman, Aaron and
                Wu, Xuemei},
  title       = {{Probe measurements of electric field and
                 electron density fluctuations at megahe
                rtz frequencies using in-shaft miniature
                 circuits}},
  publisher   = {{Princeton Plasma Physics Laboratory, Pri
                nceton University}},
  year        = 2021,
  url         = {https://doi.org/10.11578/1814954}
}
Description:

A four-tip electrostatic probe is constructed to measure high-frequency (0.1–10 MHz) fluctuations in both the electric field (one component) and electron density in a laboratory plasma. This probe also provides data for the local electron temperature and density. Circuits for high-frequency measurements are fabricated on two miniature boards, which are embedded in the probe shaft, near the tips to minimize the pickup of common-mode signals. The amplitude and phase response of two circuits to sinusoidal test signals are measured and compared with results from modeling. For both circuits, the phase shift between input and output signals is relatively small (<30°). The performance of the probe is verified in a high-density (∼1013 cm−3) and low-temperature (≲10 eV) plasma. The probe successfully measures high-frequency (∼2 MHz) fluctuations in the electric field and density, which are associated with lower hybrid drift waves. This probe can provide information on the wave-associated anomalous drag, which can be compared with the classical resistivity.

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