Identification of the energetic-particle driven GAM in the LHD
Identification of the energetic-particle driven GAM in the LHD
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DOI：
10.1088/0029-5515/55/8/083024
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发表时间：
2015-07
期刊：
影响因子：
3.3
通讯作者：
T. Ido;M. Osakabe;A. Shimizu;T. Watari;M. Nishiura;K. Toi;K. Ogawa;K. Itoh;I. Yamada;R. Yasuhara;Y. Yoshimura;S. Kato
中科院分区：
文献类型：
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作者：
T. Ido;M. Osakabe;A. Shimizu;T. Watari;M. Nishiura;K. Toi;K. Ogawa;K. Itoh;I. Yamada;R. Yasuhara;Y. Yoshimura;S. Kato
利用重离子束探针和米尔诺夫线圈在大螺旋装置等离子体中观察到了具有频率啁啾的n = 0模式，其中n是环形模式数。静电势涨落和密度涨落的空间结构对应于测地声学模（GAM）的空间结构。只有在能量为175 keV的中性束切向注入时才能观察到这种模式。用中性粒子分析仪测量了快离子的能谱，表明快离子通过逆朗道阻尼激发了模。模式频率的绝对值和温度依赖性可以通过色散关系来解释，同时考虑到快离子的测量能谱。因此，观察到的n = 0模式被确定为能量粒子驱动的GAM。
n = 0 modes with frequency chirping have been observed by a heavy ion beam probe and Mirnov coils in the large helical device plasmas, where n is the toroidal mode number. The spatial structures of the electrostatic potential fluctuation and the density fluctuation correspond to those of the geodesic acoustic mode (GAM). The modes are observed only during the tangential neutral beam injection with the energy of 175 keV. The energy spectra of fast ions measured by a neutral particle analyzer implies that the modes are excited by the fast ions through the inverse Landau damping. The absolute values and the temperature dependence of the frequency of the mode can be interpreted by the dispersion relation taking into account the measured energy spectra of the fast ions. Therefore, the observed n = 0 modes are identified as the energetic-particle driven GAM.