Zhang, M and Kim, JH and Pamidi, S and Chudy, M and Yuan, W and Coombs, TA (2012) *Study of second generation, high-temperature superconducting coils: Determination of critical current.* Journal of Applied Physics, 111. ISSN 0021-8979

## Abstract

This paper presents the modeling of second generation (2 G) high-temperature superconducting (HTS) pancake coils using finite element method. The axial symmetric model can be used to calculate current and magnetic field distribution inside the coil. The anisotropic characteristics of 2 G tapes are included in the model by direct interpolation. The model is validated by comparing to experimental results. We use the model to study critical currents of 2 G coils and find that 100μV/m is too high a criterion to determine long-term operating current of the coils, because the innermost turns of a coil will, due to the effect of local magnetic field, reach their critical current much earlier than outer turns. Our modeling shows that an average voltage criterion of 20μV/m over the coil corresponds to the point at which the innermost turns' electric field exceeds 100μV/m. So 20μV/m is suggested to be the critical current criterion of the HTS coil. The influence of background field on the coil critical current is also studied in the paper. © 2012 American Institute of Physics.

Item Type: | Article |
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Subjects: | UNSPECIFIED |

Divisions: | Div B > Electronics, Power & Energy Conversion |

Depositing User: | Cron Job |

Date Deposited: | 15 Dec 2015 12:59 |

Last Modified: | 08 Feb 2016 04:34 |

DOI: | 10.1063/1.3698317 |