TY - JOUR
T1 - Magnetization properties for Gd-Ba-Cu-O bulk superconductors with a couple of pulsed-field vortex-type coils
AU - Ida, T.
AU - Matsuzaki, H.
AU - Akita, Y.
AU - Izumi, M.
AU - Sugimoto, H.
AU - Hondou, Y.
AU - Kimura, Y.
AU - Sakai, N.
AU - Nariki, S.
AU - Hirabayashi, I.
AU - Miki, M.
AU - Murakami, M.
AU - Kitano, M.
N1 - Funding Information:
The authors are grateful to Mr. S. Tsujii and Mr. I. Ohtani for technical assistance. The present work was partly supported by the Ship&Ocean Foundation Japan.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2004/10
Y1 - 2004/10
N2 - Pulsed-field magnetization was studied for field-free cooled high-temperature superconductor (HTS) bulk cylindrical disks of melt-textured Gd-Ba-Cu-O samples at the liquid nitrogen temperature. A bulk sample was inserted in between disks of vortex-type pulsed-field copper coil immersed in the liquid nitrogen. The flux was trapped in the centre of the sample surface under the smaller pulsed peak field than the magnetization with a conventional solenoid coil. With intensifying the pulsed-field, the trapped flux density for the maximum peak remanent value in the field cooling process increases monotonously to the liquid nitrogen temperature. In the samples with strong pinning force, which shows large remanent flux on field cooling, the deviation from the conical profile of trapped field distribution was observed. This is attributed to the transient flux motion, which possibly drives temperature increase resulting in the decrease of the trapped field in the growth sector. However, the subsequent single pulsed-field remarkably compensates the formation of a well-dressed conical field density profile. Employing a couple of vortex-type coils enables us to magnetize the HTS bulk cryo-magnets effectively with reduced electric energy per pulsed-current for the magnetization with a pulsed-field solenoid. The present magnetization geometry is acceptable for application of the HTS bulk to the rotor magnet magnetized with an armature in the synchronous rotating machines.
AB - Pulsed-field magnetization was studied for field-free cooled high-temperature superconductor (HTS) bulk cylindrical disks of melt-textured Gd-Ba-Cu-O samples at the liquid nitrogen temperature. A bulk sample was inserted in between disks of vortex-type pulsed-field copper coil immersed in the liquid nitrogen. The flux was trapped in the centre of the sample surface under the smaller pulsed peak field than the magnetization with a conventional solenoid coil. With intensifying the pulsed-field, the trapped flux density for the maximum peak remanent value in the field cooling process increases monotonously to the liquid nitrogen temperature. In the samples with strong pinning force, which shows large remanent flux on field cooling, the deviation from the conical profile of trapped field distribution was observed. This is attributed to the transient flux motion, which possibly drives temperature increase resulting in the decrease of the trapped field in the growth sector. However, the subsequent single pulsed-field remarkably compensates the formation of a well-dressed conical field density profile. Employing a couple of vortex-type coils enables us to magnetize the HTS bulk cryo-magnets effectively with reduced electric energy per pulsed-current for the magnetization with a pulsed-field solenoid. The present magnetization geometry is acceptable for application of the HTS bulk to the rotor magnet magnetized with an armature in the synchronous rotating machines.
KW - Gd-Ba-Cu-O
KW - Pulsed magnetization
KW - Vortex-type coils
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U2 - 10.1016/j.physc.2003.12.082
DO - 10.1016/j.physc.2003.12.082
M3 - Article
AN - SCOPUS:4644350528
SN - 0921-4534
VL - 412-414
SP - 638
EP - 645
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - SPEC. ISS.
ER -