Designing stellarator coils by a modified Newton method using FOCUS
Designing stellarator coils by a modified Newton method using FOCUS
复制标题
使用 FOCUS 通过改进的牛顿法设计仿星器线圈
DOI：
10.1088/1361-6587/aab8c2
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Y. Wan
中科院分区：
文献类型：
--
作者：
Caoxiang Zhu;S. Hudson;Yuntao Song;Y. Wan
为了找到仿星器的最佳线圈，非线性优化算法应用在现有的线圈设计代码。然而，这些代码都没有使用的信息，从二阶导数。在本文中，我们提出了一个修改的牛顿法在最近开发的代码FOCUS。Hessian矩阵用解析导出的方程计算。它的逆近似由一个修改的Cholesky分解和应用在经典的牛顿法的迭代方案。使用这种方法，FOCUS能够从简单的初始猜测开始恢复W7-X模块化线圈。结果显示出显著的优势。
To find the optimal coils for stellarators, nonlinear optimization algorithms are applied in existing coil design codes. However, none of these codes have used the information from the second-order derivatives. In this paper, we present a modified Newton method in the recently developed code FOCUS. The Hessian matrix is calculated with analytically derived equations. Its inverse is approximated by a modified Cholesky factorization and applied in the iterative scheme of a classical Newton method. Using this method, FOCUS is able to recover the W7-X modular coils starting from a simple initial guess. Results demonstrate significant advantages.