We propose a novel flux-surface parameterization suitable for local MHD equilibrium calculations with strongly-shaped flux surfaces. The method is based on a systematic expansion in a small number of intuitive shape parameters, and reduces to the well-known Miller D-shaped parameterization in the limit where some of the coefficients are set to zero. The new parameterization is valid for up-down asymmetric plasmas and provides an improvement to the Miller form. Simultaneously, the method is rapidly convergent and requires only about half the number of shape parameters as a general Fourier representation in the pedestal.

中文翻译：

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快速收敛的磁通表面形状参数化

我们提出了一种新颖的通量表面参数化方法，适用于具有强形通量表面的局部MHD平衡计算。该方法基于少量直观形状参数的系统扩展，并在某些系数设置为零的极限范围内减少到众所周知的Miller D形参数化。新的参数化对于上下不对称等离子体有效，并且对Miller形式进行了改进。同时，该方法快速收敛，并且仅需要形状参数的大约一半即可作为基座中的一般傅立叶表示。