Plasma and Fusion Research

Volume 11, 2401043 (2016)

Regular Articles

Simulation of Contactless Crack Detection in HTS Films: Application of H-Matrix Method to Fast Matrix-Vector Multiplication
Teruou TAKAYAMA, Ayumu SAITOH1), Atsushi KAMITANI1) and Hiroaki NAKAMURA2)
Department of Informatics, Yamagata University, Yonezawa 992-8510, Japan
1)
Graduate School of Science and Engineering, Yamagata University, Yonezawa 992-8510, Japan
2)
National Institute for Fusion Science, Toki 509-5292, Japan
(Received 30 November 2015 / Accepted 3 March 2016 / Published 15 April 2016)

Abstract

Detectability of the multiple cracks in a high-temperature superconducting (HTS) film by a scanning permanent magnet method has been investigated numerically. To this end, a numerical code has been developed for performing a shielding current analysis in an HTS film with cracks. Furthermore, the GMRES(k) method and the H-matrix method are adopted in the code. By using the code, the scanning permanent magnet method can be simulated successfully. The results of the computations show that the x-coordinate of the crack endpoint cannot be estimated with increasing the magnet radius. On the other hand, the y-coordinate of the crack endpoint can be detected accurately.

Keywords

crack detection, FEM, high-temperature superconductor, permanent magnet, simulation

DOI: 10.1585/pfr.11.2401043

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