Plasma and Fusion Research

Volume 14, 2402036 (2019)

Regular Articles

Spatiotemporal Structure of Hα Emission from the Detached Plasma in GAMMA 10/PDX
Hirohiko TANAKA, Mizuki SAKAMOTO1), Naomichi EZUMI1), Akihiro TERAKADO1), Kunpei NOJIRI1), Tomohiro MIKAMI1), Yosuke KINOSHITA1), Kaede KOBAYASHI1), Masayuki YOSHIKAWA1), Junko KOHAGURA1) and Noriyasu OHNO
Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan
1)
Plasma Research Center, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
(Received 6 September 2018 / Accepted 10 January 2019 / Published 12 February 2019)

Abstract

High-speed camera measurement was performed for analyses of detached plasma fluctuation in the GAMMA 10/PDX tandem mirror device. Significant spectral peaks at frequencies of 1.5 and 3 kHz were observed to have several local maxima along the vertical, near the entrance of the V-shaped target. Wavelet analysis indicated that 1.5- and 3-kHz fluctuations became non-simultaneously strong. Their phase relationships demonstrated inversion-symmetric and symmetric features with respect to the midplane. Such spectral patterns were interpreted as the line-integral of odd- and even-mode structures. It is suspected that the vertical edge part was due to radially elongated structures with an azimuthal phase shift.

Keywords

fluctuation, plasma detachment, high-speed camera, frequency analysis, GAMMA 10/PDX

DOI: 10.1585/pfr.14.2402036

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References

  • [1] H. Tanaka et al., Phys. Plasmas 17, 102509 (2010).
  • [2] D. Carralero et al., Nucl. Fusion 58, 096015 (2018).
  • [3] H. Tanaka et al., Plasma Phys. Control. Fusion 60, 075013 (2018).
  • [4] H. Tanaka et al., Phys. Plasmas 25, 082505 (2018).
  • [5] Y. Nakashima et al., Nucl. Fusion 57, 116033 (2017).
  • [6] A. Terakado et al., AIP Conf. Proc. 1771, 050008 (2016).
  • [7] N. Ohno et al., Contrib. Plasma Phys. 44, 222 (2004).
  • [8] S. Inagaki et al., Nucl. Fusion 52, 023022 (2012).
  • [9] H. Tanaka et al., Contrib. Plasma Phys. 50, 256 (2010).