TY - JOUR
T1 - Fluctuation measurement across the broad range of the low-field side edge plasmas in the TST-2 spherical tokamak
AU - Sonehara, Masateru
AU - Nagashima, Yoshihiko
AU - Takase, Yuichi
AU - Ejiri, Akira
AU - Yamaguchi, Takashi
AU - Ambo, Takanori
AU - Kakuda, Hidetoshi
AU - Hiratsuka, Junichi
AU - Sakamoto, Takuya
AU - Shino, Ryota
AU - Wakatsuki, Takuma
AU - Watanabe, Osamu
PY - 2012
Y1 - 2012
N2 - This paper presents initial results from experimental observation of edge turbulence structures in ohmically heated plasmas on Tokyo Spherical Tokamak-2 (TST-2). The experiment was conducted using two-dimensionally movable Langmuir probes. With monitoring floating potential V f and ion saturation current I is, the radial and poloidal structures of the edge turbulence are obtained. The high coherence in fluctuations at 10-100kHz frequency was observed by the use of the Langmuir probes 90° toroidally and ∼75° poloidally distant from each other, suggesting that the fluctuations have long range correlation along a magnetic field line. To investigate nonlinear structures of the turbulence, bispectral analysis was used, and the observed auto-bicoherence pattern suggests the presence of the coupling and energy transfer between different modes.
AB - This paper presents initial results from experimental observation of edge turbulence structures in ohmically heated plasmas on Tokyo Spherical Tokamak-2 (TST-2). The experiment was conducted using two-dimensionally movable Langmuir probes. With monitoring floating potential V f and ion saturation current I is, the radial and poloidal structures of the edge turbulence are obtained. The high coherence in fluctuations at 10-100kHz frequency was observed by the use of the Langmuir probes 90° toroidally and ∼75° poloidally distant from each other, suggesting that the fluctuations have long range correlation along a magnetic field line. To investigate nonlinear structures of the turbulence, bispectral analysis was used, and the observed auto-bicoherence pattern suggests the presence of the coupling and energy transfer between different modes.
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U2 - 10.1541/ieejfms.132.499
DO - 10.1541/ieejfms.132.499
M3 - Article
AN - SCOPUS:84866932319
SN - 0385-4205
VL - 132
SP - 499-504+7
JO - IEEJ Transactions on Fundamentals and Materials
JF - IEEJ Transactions on Fundamentals and Materials
IS - 7
ER -