Designing stellarator coils by a modified Newton method using FOCUS
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 secondorder 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 W7X modular coils starting from a simple initial guess. Results demonstrate significant advantages.
 Authors:

^{[1]}
;
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^{[3]};
^{[1]}
 Univ. of Science and Technology of China, Hefei (China)
 Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
 Chinese Academy of Sciences (CAS), Hefei (China)
 Publication Date:
 Grant/Contract Number:
 AC0209CH11466; No. 201506340040
 Type:
 Accepted Manuscript
 Journal Name:
 Plasma Physics and Controlled Fusion
 Additional Journal Information:
 Journal Name: Plasma Physics and Controlled Fusion; Journal ID: ISSN 07413335
 Publisher:
 IOP Science
 Research Org:
 Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
 Sponsoring Org:
 USDOE
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
 OSTI Identifier:
 1430525
Zhu, Caoxiang, Hudson, Stuart R., Song, Yuntao, and Wan, Yuanxi. Designing stellarator coils by a modified Newton method using FOCUS. United States: N. p.,
Web. doi:10.1088/13616587/aab8c2.
Zhu, Caoxiang, Hudson, Stuart R., Song, Yuntao, & Wan, Yuanxi. Designing stellarator coils by a modified Newton method using FOCUS. United States. doi:10.1088/13616587/aab8c2.
Zhu, Caoxiang, Hudson, Stuart R., Song, Yuntao, and Wan, Yuanxi. 2018.
"Designing stellarator coils by a modified Newton method using FOCUS". United States.
doi:10.1088/13616587/aab8c2. https://www.osti.gov/servlets/purl/1430525.
@article{osti_1430525,
title = {Designing stellarator coils by a modified Newton method using FOCUS},
author = {Zhu, Caoxiang and Hudson, Stuart R. and Song, Yuntao and Wan, Yuanxi},
abstractNote = {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 secondorder 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 W7X modular coils starting from a simple initial guess. Results demonstrate significant advantages.},
doi = {10.1088/13616587/aab8c2},
journal = {Plasma Physics and Controlled Fusion},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {3}
}