Journal
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
Volume 31, Issue 5, Pages -Publisher
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/TASC.2021.3058924
Keywords
Coated conductor; hoop stress; joint; magnetic field
Funding
- High Field Laboratory for Superconducting Materials, IMR, Tohoku University
Ask authors/readers for more resources
This study investigated the tolerance of REBCO coil to electromagnetic force by applying hoop stresses and found degradation only occurred at the lap joint between CCs. A new joint structure was proposed to reduce stress concentration at the joint part, with higher tensile strength compared to traditional lap joint structure.
REBCOcoated conductors (CCs) are suitable for high field magnets due to their high in-field critical current density (J(c)) and high tensile strength. However, in order to apply the REBCO CCs to a high field magnet, it is important not only to evaluate the characteristics of short samples but also to clarify the behavior of the REBCO coil under strong electro-magnetic forces in high magnetic fields. In this study, we investigated the tolerance to the electro-magnetic force by applying hoop stresses to a REBCO double pancake coil in high magnetic fields. The REBCO coil was wound with BHO-EuBCO CCs and impregnated with epoxy resin. In order to prevent a degradation due to thermal delamination stress, fluorine-coated polyimide tapes were wound on the REBCO CCs. When a maximum hoop stress of 608 MPa was applied to the coil, normal voltage was generated and I-c degradation was confirmed in one side of double pancake. As a result of the investigation, the degradation occurred only at lap joint part between CCs in the windings, and the cause of the degradation was thought to be stress concentration at the both edges of lap joint. Since there was no I-c degradation except for the lap joint part, it is considered that the REBCO coil can withstand larger hoop stress if we can reduce the stress concentration at the joint part. We therefore proposed a new joint structure and confirmed that it has higher tensile strength than a conventional lap joint structure.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available