论文标题
轴上磁井和Mercier的任意恒星几何标准
The On-Axis Magnetic Well and Mercier's Criterion for Arbitrary Stellarator Geometries
论文作者
论文摘要
轴上磁井的简化分析形式和Mercier的互换不稳定性标准是任意三维磁场几何形式的。为此，使用基于直接坐标方法的近轴扩展是通过以径向距离与磁轴的距离表示环形磁通量的。然后，第一次将磁井和Mercier的标准写成相对于轴弧长的一维积分。与Mercier的原始作品相比，这里的推导是使用现代符号和更简化的方式提出的，以突出显示基本步骤。最后，使用几种准对称和非质量对称恒星构型（包括Wendelstein 7-X）对这些表达式进行数值验证。
A simplified analytical form of the on-axis magnetic well and Mercier's criterion for interchange instabilities for arbitrary three-dimensional magnetic field geometries is derived. For this purpose, a near-axis expansion based on a direct coordinate approach is used by expressing the toroidal magnetic flux in terms of powers of the radial distance to the magnetic axis. For the first time, the magnetic well and Mercier's criterion are then written as a one-dimensional integral with respect to the axis arclength. When compared with the original work of Mercier, the derivation here is presented using modern notation and in a more streamlined manner that highlights essential steps. Finally, these expressions are verified numerically using several quasisymmetric and non-quasisymmetric stellarator configurations including Wendelstein 7-X.
