TY - JOUR
T1 - Magnetic Flux Trapping and Flux Jumps in Pulsed Field Magnetizing Processes in REBCO and Mg-B Bulk Magnets
AU - Oka, T.
AU - Takeda, A.
AU - Oki, H.
AU - Yamanaka, K.
AU - Dadiel, L.
AU - Yokoyama, K.
AU - Häßler, W.
AU - Scheiter, J.
AU - Sakai, N.
AU - Murakami, Masato
N1 - Funding Information:
This work has been partially supported by the project named as Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation of JSPS.
Publisher Copyright:
© Published under licence by IOP Publishing Ltd.
PY - 2020/7/31
Y1 - 2020/7/31
N2 - Pulsed-field magnetization technique (PFM) is expected as a cheap and an easy way for HTS bulk materials for utilizing as intense magnets. As the generation of heat due to magnetic flux motion in bulk magnets causes serious degradation of captured fields, it is important to investigate the flux motions during PFM in various field applications. The authors precisely measured the magnetic flux motion in the cryocooled MgB2 bulk magnets containing various amount of Ti. We classified the motions to "no flux flow (NFF)", "fast flux flow (FFF)", and "flux jump (FJ)" regions. The results showed that addition of Ti shifts the field invasion area to high field areas, and expands the NFF regions. The highest field-trapping appears at the upper end of the NFF region. Since the heat generation and its propagation should attribute to the dissipation of magnetic flux, FFF leads to FJ. Compared with MgB2, we referred to GdBCO as for the flux motion. A flux jump was observed at 30 K when the pulse field of 7 T was applied to the preactivated sample, showing its stability against FJ.
AB - Pulsed-field magnetization technique (PFM) is expected as a cheap and an easy way for HTS bulk materials for utilizing as intense magnets. As the generation of heat due to magnetic flux motion in bulk magnets causes serious degradation of captured fields, it is important to investigate the flux motions during PFM in various field applications. The authors precisely measured the magnetic flux motion in the cryocooled MgB2 bulk magnets containing various amount of Ti. We classified the motions to "no flux flow (NFF)", "fast flux flow (FFF)", and "flux jump (FJ)" regions. The results showed that addition of Ti shifts the field invasion area to high field areas, and expands the NFF regions. The highest field-trapping appears at the upper end of the NFF region. Since the heat generation and its propagation should attribute to the dissipation of magnetic flux, FFF leads to FJ. Compared with MgB2, we referred to GdBCO as for the flux motion. A flux jump was observed at 30 K when the pulse field of 7 T was applied to the preactivated sample, showing its stability against FJ.
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U2 - 10.1088/1742-6596/1590/1/012025
DO - 10.1088/1742-6596/1590/1/012025
M3 - Conference article
AN - SCOPUS:85090044445
SN - 1742-6588
VL - 1590
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 1
M1 - 012025
T2 - 32nd International Symposium on Superconductivity, ISS 2019
Y2 - 3 December 2019 through 5 December 2019
ER -