In this letter, we investigate the spatial structure of a low frequency global potential oscillation, which is likely ascribed as the low frequency zonal flows, in TJ-II laboratory plasmas. In two plasmas produced by different heating schemes (electron cyclotron resonance heating and neutral beam injection heating) and characterized by different mean radial electric field structures, frequency-space-decomposed spectra of the global potential oscillation are obtained. In both cases, the oscillatory field has a single-peaked potential structure and a dipole radial electric field structure. The oscillating structure depends on its frequency as well as on the heating scheme.
本研究中，我们探讨了TJ-II实验室等离子体中一种低频全局电势振荡的空间结构，该振荡很可能归因于低频纬向流。在两种由不同加热方案（电子回旋共振加热与中性束注入加热）产生、且具有不同平均径向电场结构的等离子体中，我们获得了该全局电势振荡的频域分解谱。在两种情形下，振荡场均呈现单峰电势结构和偶极径向电场结构。该振荡结构不仅依赖于其频率，还依赖于加热方案。