Journal ArticleDOI
Magnetic Shield of High- T c Oxide Superconductors at 77 K
Koji Shigematsu,Hiroshi Ohta,Kazutomo Hoshino,Takayama Hitoshi,Osamu Yagishita,Shigeru Yamazaki,Hidefusa Takahara,Masakazu Aono +7 more
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TLDR
In this paper, a superconducting Y-Ba-Cu-O vessel was compared with those in a normal state at 290 K by measuring induced voltages in a pick-up coil inside the vessel and the ratio of the magnetic field at 77 K to that at 290 k was as good as 2×10-6 when a magnetic field of 0.03 mT at 1000 Hz was applied to the outside of the vessel.Abstract:
Magnetic shielding effects of superconducting Y-Ba-Cu-O vessels have been studied. Magnetic fields inside a Y-Ba-Cu-O vessel in a superconducting state at 77 K were compared with those in a normal state at 290 K by measuring induced voltages in a pick-up coil inside the vessel. The ratio of the magnetic field at 77 K to that at 290 K was as good as 2×10-6 when a magnetic field of 0.03 mT at 1000 Hz was applied to the outside of the vessel. This attenuation ratio is good enough for neuromagnetic measurements with a SQUID magnetometer.read more
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Journal ArticleDOI
Neuromagnetic SQUID measurements in a helmet-type superconducting magnetic shield of BSCCO
H. Ohta,A. Koike,K. Hoshino,H. Kotaka,E. Sudoh,K. Kato,H. Takahara,Yoshinori Uchikawa,K. Shinada,M. Takahata,Y. Yamada,Toshiaki Matsui +11 more
TL;DR: In this article, a superconducting quantum interference device (SQUID) magnetometer has successfully detected magnetic fields emitted from a human brain in a helmet-size superconding magnetic shield of the high-T/sub c/ superconductor Bi-Sr-Ca-Cu-O/sub x /(BSCCO).
Patent
Superconducting magnetic shield
Hiroshi Ohta,Masakazu Aono,Kazuhiko Kato,Kazutomo Hoshino,Hidefusa Takahara,Tomonobu Nakayama,Eiichi Sudoh +6 more
TL;DR: In this paper, a superconducting magnetic shield and a magnetic shielding apparatus were provided to measure an extremely weak magnetic field such as magnetoencephalographic waves by reducing the influence of magnetic field of the earth or magnetic noises.
Journal ArticleDOI
Shielding effects in ceramic superconductors
TL;DR: In this article, the authors studied the shielding properties of high-temperature superconductors in DC and AC magnetic fields using Bean's critical state model and models, which account for the field dependence of the critical current density.
Journal ArticleDOI
Magnetic shield of high-T/sub c/ Bi-Pb-Sr-Ca-Cu-O superconductors at 77 K for SQUID measurements
TL;DR: In this paper, a relatively large high T/sub c/ Bi-Pb-Sr-Ca-Cu-O superconducting magnetic shield vessel was developed for biomagnetic measurements with a SQUID.
Journal ArticleDOI
Study of the propagation of an AC magnetic field through superconducting thick films
TL;DR: In this article, a non-linear dependence of critical magnetic field H* on both thickness and critical current density Jc of the specimen has been observed, showing that the shielding effectiveness increases exponentially with decreasing field intensity.
References
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Magnetic shielding using high-Tcsuperconductor
TL;DR: In this article, the magnetic shielding has been investigated by measuring magnetic coupling between primary and secondary coils separated by a high-Tc superconductor, which can explain the existence of superconductivity related surface current, which flows out from front to rear surface to couple with the secondary coil.