TY - JOUR
T1 - Temperature rise in melt-textured large grain superconducting bulk magnets during their magnetizing operations
AU - Oka, Tetsuo
AU - Yokoyama, Kazuya
AU - Fujishiro, Hiroyuki
AU - Noto, Koshichi
N1 - Funding Information:
This study was supported by IWATE CREATE project driven by Japan Science and Technology Agency and Iwate prefecture authorities.
PY - 2007/9/1
Y1 - 2007/9/1
N2 - The temperature rises in the melt-processed RE-Ba-Cu-O (RE = Y, Sm, Gd) bulk superconductors were evaluated when the magnetizing operations were performed by the field cooling (FC), the zero field cooling (ZFC) and the pulsed field magnetization (PFM) processes. It is known that the field-trapping ability of the superconducting bulk magnets is restricted by the heat generation due to the flux motion inside the sample not only in the PFM but also even in the FC process. In this paper, the authors discuss the mechanism of heat generation and the flux motions by means of the temperature and resultant trapped field measurement during three magnetizing processes. The sample was cooled in a 5 T static field and then the field was removed with various descending rates (2.53-11.3 mT/s) in FC method. The fields were also applied and then removed with the same rates after setting the sample in the superconducting state in ZFC. These data were compared with the results obtained in the PFM. The temperature evolutions have shown apparent peaks that correspond to the heat generation in their magnetizing processes. The maximum temperature rises have reached 5.9 K in FC and 7.6 K in ZFC operated at 57.6 K and 51.5 K, respectively. The temperature rise exhibited 2 K even when the slowest rate of 2.53 mT/s was applied in FC mode. These data suggest it is crucial to take the heat generation into account in estimating the field-trapping ability of the high performance bulk magnets.
AB - The temperature rises in the melt-processed RE-Ba-Cu-O (RE = Y, Sm, Gd) bulk superconductors were evaluated when the magnetizing operations were performed by the field cooling (FC), the zero field cooling (ZFC) and the pulsed field magnetization (PFM) processes. It is known that the field-trapping ability of the superconducting bulk magnets is restricted by the heat generation due to the flux motion inside the sample not only in the PFM but also even in the FC process. In this paper, the authors discuss the mechanism of heat generation and the flux motions by means of the temperature and resultant trapped field measurement during three magnetizing processes. The sample was cooled in a 5 T static field and then the field was removed with various descending rates (2.53-11.3 mT/s) in FC method. The fields were also applied and then removed with the same rates after setting the sample in the superconducting state in ZFC. These data were compared with the results obtained in the PFM. The temperature evolutions have shown apparent peaks that correspond to the heat generation in their magnetizing processes. The maximum temperature rises have reached 5.9 K in FC and 7.6 K in ZFC operated at 57.6 K and 51.5 K, respectively. The temperature rise exhibited 2 K even when the slowest rate of 2.53 mT/s was applied in FC mode. These data suggest it is crucial to take the heat generation into account in estimating the field-trapping ability of the high performance bulk magnets.
KW - Bulk superconductor
KW - Heat generation
KW - Magnetization
KW - Melt-process
KW - Trapped field
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U2 - 10.1016/j.physc.2007.03.368
DO - 10.1016/j.physc.2007.03.368
M3 - Article
AN - SCOPUS:34548169076
VL - 460-462 II
SP - 748
EP - 749
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - SPEC. ISS.
ER -