TY - JOUR
T1 - Dynamics of nonlinear coupling between electron-temperature-gradient mode and drift-wave mode in linear magnetized plasmas
AU - Moon, Chanho
AU - Kaneko, Toshiro
AU - Hatakeyama, Rikizo
PY - 2013/9/10
Y1 - 2013/9/10
N2 - A high-frequency (∼0.4 MHz) fluctuation is excited by an electron temperature gradient (ETG) perpendicular to magnetic field lines, which is consistent with an ETG mode. When the fluctuation amplitude of the ETG mode exceeds a certain threshold, the mode gradually becomes saturated and a low-frequency (∼7 kHz) fluctuation which is originally caused by a drift wave is enhanced, corresponding to the saturation of the ETG mode. In addition, a nonlinear coupling, specifically, the bicoherence between the ETG mode and the drift wave mode, begins to increase when the ETG strength exceeds the threshold, which simultaneously occurs with the saturation of the ETG mode. Thus, it was determined that the ETG mode stimulates the drift wave mode excitement via multiscale nonlinear interaction between the high-frequency (∼MHz) and low-frequency (∼kHz) fluctuations, which ultimately causes ETG mode energy to be transferred to the drift wave mode.
AB - A high-frequency (∼0.4 MHz) fluctuation is excited by an electron temperature gradient (ETG) perpendicular to magnetic field lines, which is consistent with an ETG mode. When the fluctuation amplitude of the ETG mode exceeds a certain threshold, the mode gradually becomes saturated and a low-frequency (∼7 kHz) fluctuation which is originally caused by a drift wave is enhanced, corresponding to the saturation of the ETG mode. In addition, a nonlinear coupling, specifically, the bicoherence between the ETG mode and the drift wave mode, begins to increase when the ETG strength exceeds the threshold, which simultaneously occurs with the saturation of the ETG mode. Thus, it was determined that the ETG mode stimulates the drift wave mode excitement via multiscale nonlinear interaction between the high-frequency (∼MHz) and low-frequency (∼kHz) fluctuations, which ultimately causes ETG mode energy to be transferred to the drift wave mode.
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U2 - 10.1103/PhysRevLett.111.115001
DO - 10.1103/PhysRevLett.111.115001
M3 - Article
AN - SCOPUS:84884272852
SN - 0031-9007
VL - 111
JO - Physical Review Letters
JF - Physical Review Letters
IS - 11
M1 - 115001
ER -