In this article, we report the latest results for the impacts of the isotope mass and the plasma heating scenario on the spatiotemporal characteristics of the low-frequency zonal flow (ZF)-like electrostatic oscillation found in the plasma edge of the TJ-II stellarator. The radial profile of the toroidal cross-coherence in low-frequency floating potential fluctuations (1 < f < 25 kHz), known as long-range correlations (LRCs), was explored along the plasma boundary region by a dual Langmuir probe system. The study was performed using electron cyclotron resonance heating (ECRH)- and neutral beam injection (NBI)-heated plasmas with two different isotope concentrations: pure hydrogen plasmas and plasmas dominated by deuterium (). The highest toroidal coherence levels are detected for floating potential oscillations at less than 10 kHz in hydrogen and deuterium plasmas, in both the ECRH and NBI heating schemes. The radial extent of the LRC profile is clearly larger in the ECRH than in the NBI-heated plasma scenarios. While the maximum amplitude of the LRC does not show a significant dependence on isotope mass, the relation between the LRCs' radial sizes in plasmas and different isotope masses increases with the isotope mass in NBI-heated scenarios. These results provide the first experimental observation of ZFs with a larger radial size in deuterium than in hydrogen plasmas.
本篇文章报告了同位素质量和等离子体加热方案对TJ-II仿星器等离子体边缘低频带状流（ZF）类静电振荡时空特性的最新影响结果。通过双朗缪尔探针系统，沿等离子体边界区域测量了低频浮电位涨落（1 < f < 25 kHz）的环向互相关性的径向分布，即长程相关（LRC）。研究在电子回旋共振加热（ECRH）和中性束注入（NBI）两种加热方案下，针对两种不同同位素组成的等离子体进行：纯氢等离子体和以氘为主的等离子体。在氢和氘等离子体中，对于低于10 kHz的浮电位振荡，在ECRH和NBI两种加热方案下均检测到最高的环向相干性。LRC剖面的径向范围在ECRH加热方案下明显大于NBI加热方案。虽然LRC的最大幅度并未显示出对同位素质量的显著依赖，但在NBI加热方案下，LRC的径向尺寸与等离子体同位素质量之间的关系表现为随同位素质量增加而增大。这些结果首次实验观察到，在氘等离子体中带状流的径向尺寸大于氢等离子体中的情况。