• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.169-171
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• 2001

The transport loss of a Bi-2223 tape exposed to external magnetic field was investigated. The results show that the transport loss is independent on voltage lead arrangements in case the magnetization loss is compensated. An serious increase of the transport loss due to external magnetic fields is observed. The loss is described well by dynamic resistance loss in relatively high fields, but another mechanism than the dynamic resistance must be responsible for the increase of the loss in low fields. The transport loss is also dependent strongly on the orientation of the applied field.

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.49-49
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• 2004

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.34-34
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• 2004

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.83-83
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• 2009

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.111-111
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• 2009

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.47-47
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• 2004

• Journal of the Korean Magnetics Society
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• v.5 no.1
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• pp.1-7
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• 1995

${(Fe_{0.85}Co_{0.15})}_{75}Al_{7}B_{18-x}Nb_{x}(x=2,\;4\;and\;6\;at%)\;and\;{(Fe_{0.85}Co_{0.15})}_{75}Al_{y}B_{21-y}Nb_{4}(y=3,\;5,\;7,\;9\;at%)$ alloys were prepared by a single-roll quenching method. Microstructure and magnetic properties of the alloys such as saturation magnetization, initial permeability, coercive force and power loss have been investigated as functions of composition and armea1ing temperature. Nanocrystallines are obtained by armealing of as-prepared amorphous alloys in all compositions except the alloy of 9 at% AI. Saturation magnetization increases after armea1ing and, decreases with Nb content. However, AI and B affects the saturation magnetization insignificantly. Initial perrreability of nanocrystallized alloy at 50 kHz is improved roore than twice compared to that of the as-prepared alloy. Coercive force and core loss reach less than half after armea1ing.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.5
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• pp.204-210
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• 2005

Alternating current (AC) losses of two Bi-2223 ([Bi, Pb]: Sr: Ca: Cu: O = 2:2:2:3) tapes [(Tape I, un-twist-pitch) and the other with a twist-pitch of 10 mm (Tape II)] were measured and compared. These samples, produced by the powder-in-(Ag) tube (PIT) method, are multi-filamentary. Also, it's produced by non-twist and different twist pitch (8, 10, 13, 30, 50 and 70 mm). The critical current measurement was carried out under the environment in liquid Nitrogen and in zero-field by 4-probe method. Susceptibility measurements were conducted while cooling in a magnetic field. Flux loss measurements were conducted as a function of ramping rate, frequency and field direction. The AC flux loss increases as the twist-pitch of the tapes decreased, in agreement with the Norris Equation. Neutron-diffraction measurements have been carried out investigate the crystal structure, magnetic structures, and magnetic phase transitions in Bi-2223([Bi, Pb]:Sr:Ca:Cu:O)

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.6
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• pp.211-215
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• 2003

Alternating current (AC) losses of two Bi-2223 ([Bi, Pb] : Sr : Ca : Cu :O = 2:2:2:3) tapes [one untwisted (Tape I, twist-pitch of $\infty$ mm) and the other with a twist-pitch of 8mm (Tape II) ] were measured and compared. These samples, produced by the powder-in-tube (PIT) method, are multi-filamentary and have a Ag/Au and Ag matrix, respectively. Susceptibility measurements were conducted while cooling in a magnetic field. Flux loss measurements were conducted as a function of ramping rate, frequency and field direction. The AC flux loss increases as the twist-pitch of the tapes decreased, in agreement with the Norris Equation.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1225-1227
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• 2005

A Bi-2223 tape has beer developed for power applications such as a fault current limiter, a power cable and a superconducting magnetic energy storage system. In such applications, the Bi-2223 tape carries time varying transport current and in addition experiences time varying external magnetic field. It is well known that the external magnetic field not only causes magnetization loss in the Bi-2223 tape, but also drastically increases transport loss due to a so-called "dynamic resistance". We developed an evaluation setup, which can measure transport loss in external at magnetic fields. Using this equipment, we measured the dynamic resistances for various amplitudes and frequencies of an external ac magnetic field perpendicular to the face in the tape. Simultaneously we investigated the effect of an external ac field on transport loss with different experimental conditions. This paper describes test results and discussions on correlation between the dynamic resistance and the transport loss for the Bi-2223 tape.