Development of YBCO power devices in Japan

Fujiwara, N.; Hayashi, H.; Nagàya, Shigeo; Shiohara, Yuh

doi:10.1016/j.physc.2010.05.015

Cited by 38 publications

(8 citation statements)

References 8 publications

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“…In turn, XPS study provides experimental evidence that for a while after quenching YBa 2 Cu 3 O 6+ , its holes are located on the oxygen sites O(4), that corresponds to a weak charge transfer from CuO  to CuO 2 . Over time, however, the hole charge shifts to the copper sites Cu (1), that leads to enhancement of the charge transfer between the planes. Thus, XPS study explains the nature of aging effects regardless of oxygen ordering.…”

Section: Discussionmentioning

confidence: 99%

On the room-temperature aging effects in YBa 2 Cu 3 O 6+δ

Фетисов¹,

Кожина²,

Эстемирова³

et al. 2015

Physica C: Superconductivity and its Applications

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a b s t r a c tThe aging effects in YBa 2 Cu 3 O 6+d have been investigated on the low-speed quenched samples in contrast to other similar studies where the high-speed quenched samples were examined. In the framework of the investigation, XPS analysis has been conducted for the samples stored after quenching for the specified times s and a detailed experimental dependence of the YBa 2 Cu 3 O 6+d lattice parameters a, b, and c on both d and s has been obtained. The regime of low-speed quenching results in a threefold increase in the aging effect magnitude. Particular cases of the c(d; s) dependence are well described by a second-order polynomial with applying different coefficients for different s. The behavior c has been explained on the basis of a simple model of the Coulomb interaction between the CuO 2 and CuO d structural planes, in which the hole charge transfer from CuO d to CuO 2 takes place providing the standard level of T c in YBa 2 Cu 3 O 6+d (this level is characterized by a maximum T c of 93 K at d = 0.9). It has been demonstrated that the c(d; s) dependence is a good alternative to assessing the hole concentration in YBa 2 Cu 3 O 6+d . By analyzing the c(d; s) experimental dependence as well as the data on the hole localization in the pairs CuAO obtained by XPS, the authors have made a conclusion about the nature of observed aging effects. The latter are likely to be related to the transition of the Cu 3d 9 L À1 electron configuration to Cu 3d 8 for copper in the basal plane of YBa 2 Cu 3 O 6+d at RT.

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Section: Discussionmentioning

confidence: 99%

On the room-temperature aging effects in YBa 2 Cu 3 O 6+δ

Фетисов¹,

Кожина²,

Эстемирова³

et al. 2015

Physica C: Superconductivity and its Applications

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“…In particular, coated-conductor YBCO has made substantial advancements in terms of its cost, mechanical strength, critical current density, current density capacity in magnetic fields, stability in long cables, and commercial availability 1 . A measure of its maturity for engineering applications, YBCO is now being routinely incorporated into designs for military and commercial power applications [17,18].…”

Section: High-temperature Superconductorsmentioning

confidence: 99%

An initial study of demountable high-temperature superconducting toroidal field magnets for the Vulcan tokamak conceptual design

Hartwig

Haakonsen

Mumgaard

et al. 2012

Fusion Engineering and Design

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“…C OILS wound with coated conductor are attracting considerable interest because of the high magnetic field they can produce and easy cooling by using a cryo-cooler [1]- [5]. Ac losses and field qualities are major concerns in some magnets using coils wound with coated conductors, and numerical electromagnetic field analyses are powerful tools to evaluate them.…”

Section: Introductionmentioning

confidence: 99%

Efficient and Practical Models for Numerical Electromagnetic Field Analyses of Three-Dimensional-Shape Coils Wound With Coated Conductor

Sogabe

Tsukamoto

Mifune

et al. 2015

IEEE Trans. Appl. Supercond.

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We have been developing a model for numerical electromagnetic field analyses of three-dimensional-shape coils wound with coated conductor. To analyze three-dimensional-shape coils in a reasonable computation time, we applied thin-strip approximation and other two approximations to our model: a nested-loops approximation and a block approximation. In a nested-loops approximation, each coil turn was approximated as cumulated closed-loops, in a block approximation, several consecutive turns were modeled with an identical current distribution: the bundle of these consecutive turns was called as a block. Analyses were carried out for a single pancake coil to evaluate the errors caused by these approximations. The current profiles as well as temporal evolution of ac losses were compared in various analyses with or without the nested-loops approximation and the block approximation. These approximations were applied to the numerical electromagnetic field analyses of a part of a saddle-shape coil.

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Development of YBCO power devices in Japan

Cited by 38 publications

References 8 publications

On the room-temperature aging effects in YBa 2 Cu 3 O 6+δ

On the room-temperature aging effects in YBa 2 Cu 3 O 6+δ

An initial study of demountable high-temperature superconducting toroidal field magnets for the Vulcan tokamak conceptual design

Efficient and Practical Models for Numerical Electromagnetic Field Analyses of Three-Dimensional-Shape Coils Wound With Coated Conductor

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