A key feature of the stellarator is its inherent three-dimensional magnetic configuration, which leads to numerous differences in plasma physics between stellarators and tokamaks. The influence of this three-dimensional geometry on ion temperature gradient (ITG) modes in the Chinese First Quasi-axisymmetric Stellarator is investigated through linear gyrokinetic simulations using the gyrokinetic Vlasov code. Across different radial and toroidal positions, the ITG mode exhibits a strong toroidal dependence and a weak radial dependence. The eigenmode localization is primarily determined by the perpendicular wavenumber and the normal curvature : the ITG mode peaks where is negative and is minimized. For ITG modes with , the growth rate mainly exhibits a toroidal dependence. As the toroidal angle increases, the peak growth rate decreases and shifts to the low region. For modes with , the most unstable modes acquire a finite at all three radial positions for , and at for . This finite alters the value of and modifies its distribution along the field line, thereby changing the eigenmode structure. By combining the eigenmode structure with the overall distributions of magnetic geometry parameters, the variation of the growth rate across different spatial positions can be qualitatively estimated.
恒星器的一个关键特征是其固有的三维磁位形，这导致恒星器与托卡马克在等离子体物理方面存在诸多差异。利用回旋动理学Vlasov代码，通过线性回旋动理学模拟，研究了中国第一台准轴对称恒星器中这种三维几何对离子温度梯度（ITG）模的影响。在不同的径向和环向位置，ITG模表现出强烈的环向依赖性和较弱的径向依赖性。本征模的局域化主要由垂直波数 和法向曲率 决定：ITG模在 为负且 最小化的位置达到峰值。对于 的ITG模，增长率主要表现出环向依赖性。随着环向角的增大，峰值增长率减小并向低 区域移动。对于 的模，最不稳定模在 时于所有三个径向位置获得有限的 ，在 时于 处获得有限的 。这种有限的 改变了 的值并修正了其沿磁力线的分布，从而改变了本征模结构。通过将本征模结构与磁几何参数的整体分布相结合，可以定性估计不同空间位置处增长率的变化。