Open AccessEffect of non-uniform proton irradiation on the critical current of REBCO tapes
Author(s) -
Hirokazu Yamamoto,
Suguru Ito,
Misako Miwa,
S. Matsuyama,
Hidetoshi Hashizume
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1559/1/012045
Subject(s) - irradiation , materials science , flux pinning , enhanced data rates for gsm evolution , critical current , condensed matter physics , field (mathematics) , current (fluid) , vortex , composite material , superconductivity , thermodynamics , physics , nuclear physics , telecommunications , mathematics , computer science , pure mathematics
Generally, uniformly-distributed irradiation defects such as artificial pinning centers improve the critical current, I c , of REBCO tapes in strong external field. On the other hand, at self-field or low field, irradiation is not effective for improving I c . However, if non-uniform pinning center distribution similar to vortex profile is assumed, this would increase I c at selffield. Therefore, in this study, we experimentally investigated the effect of partial irradiation on I c based on the assumption. We prepared REBCO tapes irradiated with trihydrogen cations in the c-axis direction. Three different patterns of defects were examined; overall, edge-only and center-only irradiations. We measured I c at 77 K, 25 K and 15 K using the four terminal method. Results showed that, while I c was not improved after the irradiations for each pattern, I c behaviour depends on the patterns; edge-only-irradiated tapes showed the highest I c and overall irradiation caused the largest I c degradation at 77 K. However, center-only-irradiated tapes showed the lowest critical current at 25 K and 15 K which may be due to enhancement of flux pinning effect at lower temperature. Moreover, pinning centers in the edge region might be more effective to increase I c , though further investigation on the effect of non-uniform pinning centers is required.