Evaluation of Electron Temperature Fluctuations Using Two Different Probe Techniques in Plasma Assembly for Nonlinear Turbulence Analysis (PANTA)

K, Kawashima; Miyoshi, Y.; Oldenbürger, S.; Inagaki, S.; Arakawa, Hiroyuki; Nagashima, Yoshihiko; Yamada, Teppei; Sasaki, M.; Kobayashi, Tatsuya; Uriu, Kazuya; Sugita, S.; Yagi, M.; Kasuya, Naohiro; Fujisawa, A.; Itoh, Sanae I.; Itoh, K.

doi:10.1585/pfr.6.2406118

Cited by 11 publications

(11 citation statements)

References 4 publications

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“…According to the experiments in PANTA device, 20,21 we focus on high density n e $ 1 Â10 19 m À3 with low temperature T e $ 5 eV plasmas in an argon discharge. Neutral particles exist even in the core of the plasma 22 so that its effect has to be considered.…”

Section: A Modelmentioning

confidence: 99%

Formation mechanism of steep wave front in magnetized plasmas

et al. 2015

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Bifurcation from a streamer to a solitary drift wave is obtained in three dimensional simulation of resistive drift waves in cylindrical plasmas. The solitary drift wave is observed in the regime where the collisional transport is important as well as fluctuation induced transport. The solitary drift wave forms a steep wave front in the azimuthal direction. The phase of higher harmonic modes are locked to that of the fundamental mode, so that the steep wave front is sustained for a long time compared to the typical time scale of the drift wave oscillation. The phase entrainment between the fundamental and second harmonic modes is studied, and the azimuthal structure of the stationary solution is found to be characterized by a parameter which is determined by the deviation of the fluctuations from the Boltzmann relation. There are two solutions of the azimuthal structures, which have steep wave front facing forward and backward in the wave propagation direction, respectively. The selection criterion of these solutions is derived theoretically from the stability of the phase entrainment. The simulation result and experimental observations are found to be consistent with the theoretical prediction.

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Section: A Modelmentioning

confidence: 99%

Formation mechanism of steep wave front in magnetized plasmas

et al. 2015

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“…It can measure ion saturation current at r = 4 cm and 32 different azimuthal locations, simultaneously floating potential alternately in azimuthal direction. In PANTA, electron temperature fluctuation level is lower than density and potential fluctuations [5]. Thus, the ion saturation current fluctuation and the floating potential fluctuation can be considered as electron density fluctuation and space potential fluctuation respectively.…”

Section: Methodsmentioning

confidence: 99%

Estimation of Particle Flux Driven by Coherent Mode Using of Statistical Conditional Averaging

Kawachi

Inagaki

Hasamada

et al. 2019

Plasma and Fusion Research

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We proposed a new method to evaluate particle flux in magnetized turbulent plasma. To extract fundamental fluctuation pattern, we used template method which is a kind of statistical conditional averaging technique. The method allows as not only to extract coherent patterns of density and potential fluctuations but also to evaluate time delay between them. We succeeded to calculate particle flux driven by fluctuation pattern and observed this pattern drives inward particle flux. Result obtained by the method is in good agreement with that obtained by a conventional method.

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“…Similar to observations in a previous cylindrical device [6], fluctuations are composed of drift waves and nonlinearly driven fluctuations. Illustrations of the device can be found in [7]. Profiles of plasma density n e , electron temperature T e and floating potential V fl shown in Fig.…”

Section: Experimental Setup and Mach Probe Designmentioning

confidence: 99%

“…where I + and I − are the time averaged ion saturation currents collected by the upstream and downstream facing probes respectively, T i and T e are the ion and electron temperatures in eV and c s = √ T e /m i is the ion sound velocity. Measurements by triple probe and conditional sampled single probe indicated electron temperatures about 1 eV [7] and accordingly, T e 1.5 eV has been used here. The ion temperature has not been measured yet and is assumed to be T i 0.1 − 0.5 eV.…”

Section: Flow Measurement Principlementioning

confidence: 99%

Configuration of Flows in a Cylindrical Plasma Device

Oldenbürger

Uriu

Kobayashi

et al. 2012

Plasma and Fusion Research

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Ion flow is studied in the cylindrical magnetized Argon plasma of the PANTA device using several experimental methods. Time delay estimation technique (TDE) is used to measure the azimuthal propagation of density fluctuations between two electrostatic probes. Ion flux is also studied in azimuthal and axial direction using a newly installed Mach probe. TDE shows velocity profiles qualitatively consistent with expected drift wave propagation and E × B rotation. The Mach probe shows a maximum azimuthal flow and an axial flow shear close to the maximum density gradient and maximum fluctuation position. Striking differences exist in the detected axial ion flows depending on the discharge parameters. In high neutral pressure conditions reversal of axial ion flow was detected in the outer part of the plasma column. Temporal evolution of flows and fluctuations are compared as a first step to assess interplay between plasma turbulence and flows in the radial, axial and azimuthal directions.

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Evaluation of Electron Temperature Fluctuations Using Two Different Probe Techniques in Plasma Assembly for Nonlinear Turbulence Analysis (PANTA)

Cited by 11 publications

References 4 publications

Formation mechanism of steep wave front in magnetized plasmas

Formation mechanism of steep wave front in magnetized plasmas

Estimation of Particle Flux Driven by Coherent Mode Using of Statistical Conditional Averaging

Configuration of Flows in a Cylindrical Plasma Device

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