Plasma and Fusion Research

Volume 14, 1402114 (2019)

Regular Articles

Comparison of Conditional Average Using Threshold and Template Methods for Quasi-Periodic Phenomena in Plasmas

Fumiyoshi KIN¹⁾, Kimitaka ITOH^2,3,4), Tim HAPPEL⁵⁾, Gregor BIRKENMEIER^5,6), Akihide FUJISAWA^4,7), Sigeru INAGAKI^4,7), Sanae-I. ITOH^4,7,8), Ulrich STROTH^5,6) and ASDEX Upgrade Team

1): Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga Koen, Kasuga, Fukuoka 816-8580, Japan
2): Institute of Science and Technology Research, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan
3): National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
4): Research Center for Plasma Turbulence, Kyushu University, 6-1 Kasuga Koen, Kasuga, Fukuoka 816-8580, Japan
5): Max Plank Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching, Germany
6): Physik-Department E28, Technische Universitat München, James-Franck-Str. 1, 85748 Garching, Germany
7): Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga Koen, Kasuga, Fukuoka 816-8580, Japan
8): Department of Innovative Energy Science and Engineering, Graduate School of Enginerring, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan

(Received 16 April 2019 / Accepted 16 May 2019 / Published 19 June 2019)

Abstract

The comparison of conditional averaging using so-called threshold and template methods is made in their application on quasi-periodic burst of I-mode in ASDEX Upgrade (AUG) I-mode plasma. For obtaining conditionally averaged waveforms, three different manners to determine the ‘clocks’, using raw signal, envelope of the signal and numerical filtering, are applied to each method. The comparison demonstrates the excellency of the template method to extract typical characteristics of target phenomena in its uniqueness to select the ensemble waveforms and its good convergence property.

Keywords

conditional averaging, template method, threshold method, magnetic burst, intermittence, ASDEX Upgrade, I-mode plasma

DOI: 10.1585/pfr.14.1402114

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