[Table of Contents]

Plasma and Fusion Research

Volume 10, 3401028 (2015)

Regular Articles


Intermittent Behavior of Local Electron Temperature in a Linear ECR Plasma
Shinji YOSHIMURA, Kenichiro TERASAKA1), Eiki TANAKA1), Mitsutoshi ARAMAKI2) and Masayoshi Y. TANAKA1)
National Institute for Fusion Science, 322-6 Oroshi, Toki 509-5292, Japan
1)
Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1 Kasuga-koen, Kasuga 816-8580, Japan
2)
College of Industrial Technology, Nihon University, 1-2-1 Izumi-cho, Narashino 275-8575, Japan
(Received 25 November 2014 / Accepted 17 February 2015 / Published 16 April 2015)

Abstract

An intermittent behavior of local electron temperature has been observed in a linear laboratory plasma, where a high-temperature region that has circular cross-section is formed along the magnetic field line for a short period of time. The floating potential signals which contain sporadic large-amplitude negative spikes associated with the electron temperature intermittency are analyzed statistically for various gas discharges. All the probability density functions of waiting time for different gas discharges exhibit exponential distributions, indicating that the random nature of this phenomenon, or the underlying Poisson process, is a universal property. On the other hand, mean duration of the intermittent events depends on the atomic mass of discharge gas species, showing that the dynamics of heavier particles may play an important role in this intermittency.


Keywords

intermittency, laboratory plasma, electron cyclotron resonance, local electron temperature, floating potential, probability density function, Poisson process

DOI: 10.1585/pfr.10.3401028


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This paper may be cited as follows:

Shinji YOSHIMURA, Kenichiro TERASAKA, Eiki TANAKA, Mitsutoshi ARAMAKI and Masayoshi Y. TANAKA, Plasma Fusion Res. 10, 3401028 (2015).