Teion Kogaku (journal of The Cryogenic Society of Japan)最新文献_第9页

R-Al2O3基板上EuBa2Cu3O7-δ薄膜の超伝導特性及び結晶成長に対する厚膜CeO2バッファ層の表面性状の影響 R-Al2O3底板上EuBa2Cu3O7-δ薄膜的超导特性和厚膜CeO2缓冲层表面性状对晶体生长的影响

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.41.193

靖之太田, 純子佐久間, 豊木村, 修道上

{"title":"R-Al2O3基板上EuBa2Cu3O7-δ薄膜の超伝導特性及び結晶成長に対する厚膜CeO2バッファ層の表面性状の影響","authors":"靖之太田, 純子佐久間, 豊木村, 修道上","doi":"10.2221/JCSJ.41.193","DOIUrl":"https://doi.org/10.2221/JCSJ.41.193","url":null,"abstract":"A buffer layer is indispensable for preventing chemical reactions between high-temperature superconducting thin films and R-Al2O3. CeO2 is a promising buffer layer. However, when a CeO2 buffer layer with a thickness of more than 50 nm is sputter-deposited onto a R-Al2O3 substrate, grains with facets grow and a high-quality EuBa2Cu3O7-δ (EBCO) thin film do not grow on the buffer layer. In order to fabricate a flat and facet-free CeO2 buffer layer and a high-quality EuBa2Cu3O7-δ (EBCO) thin film, we examined the effects of off-center distance (Doff) and substrate temperature (Ts) of the CeO2 buffer layer on the properties of CeO2 buffer layers and EBCO thin films. Doff was defined by the distance from the on-center position to the off-center position. The deposition rate (Rd) was controlled by Doff. A 300-nm-thick CeO2 buffer layer and a 150-nm-thick EBCO thin film were prepared by RF and DC magnetron sputtering, respectively. The surface morphology of CeO2 buffer layer was dependent on Ts and Doff. At Ts = 650°C and Doff = 30 mm, minute grains grew. When Doff was increased to 50 mm, grains with (111) facet planes grew. The surface roughness (Rz) of the CeO2 buffer layer rapidly increased as Doff was increased. The orientation of the EBCO thin film was dependent on the Doff of the buffer layer. At Doff = 0 ∼ 30 mm, only (00l) peaks of an EBCO thin film were observed in X-ray diffraction patterns. Typical rectangular grains were observed on the surface of the thin film. At Doff values over 40 mm, (110) or (103) peaks, in addition to (00l) peaks, were observed. At Doff = 30 mm, the EBCO thin film exhibited a critical temperature (Tce) of approximately 89 K and a critical current density (Jc) of approximately 3.6 MA/cm2.","PeriodicalId":285677,"journal":{"name":"Teion Kogaku (journal of The Cryogenic Society of Japan)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122300645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Recent Status of Studies on the Neutron Irradiation Effect Focusing on Nb3Sn and Nb3Al Strands Nb3Sn和Nb3Al链中子辐照效应的研究现状

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.46.176

A. Nishimura

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引用次数: 0

Photomixing Optical-Microwave Transformer Coupled with High-TC Josephson Junctions. 高tc约瑟夫森结耦合的光敏光微波变压器。

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.38.9

T. Kiwa, M. Tonouchi

引用次数: 0

Engineering Development of an HTS Floating Coil for the Mini-RT Project 用于Mini-RT项目的高温超导浮动线圈的工程开发

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.39.193

N. Yanagi, T. Mito, J. Morikawa, Y. Ogawa, S. Hamaguchi, Y. Hishinuma, K. Ohkuni, D. Hori, M. Iwakuma, T. Uede

{"title":"Engineering Development of an HTS Floating Coil for the Mini-RT Project","authors":"N. Yanagi, T. Mito, J. Morikawa, Y. Ogawa, S. Hamaguchi, Y. Hishinuma, K. Ohkuni, D. Hori, M. Iwakuma, T. Uede","doi":"10.2221/JCSJ.39.193","DOIUrl":"https://doi.org/10.2221/JCSJ.39.193","url":null,"abstract":"A magnetically-levitated superconducting coil device, Mini-RT, has been constructed using a high temperature superconductor (HTS) for the purpose of examining a new magnetic confinement scheme of high-beta non-neutral plasmas. The floating coil is wound with silver-sheathed Bi-2223 tapes, and it is operated in the temperature range of 20-40 K. A number of studies and experiments were carried out in order to realize the necessary system. One of them was to demonstrate magnetic levitation using a miniature HTS floating coil having a diameter of 80 mm. The coil was fabricated using Bi-2223/Ag tapes of 12 m and excited by field cooling with liquid nitrogen. The magnetic levitation was examined using a real-time feedback control system with laser displacement gauges. Additionally, a persistent current switch (PCS) has been developed using Bi-2223/Ag tapes of 21 m, and a prototype HTS-PCS was tested in a cryostat. After construction of the floating coil and HTS-PCS for the Mini-RT device was completed, excitation tests were carried out in the cryostat and the basic properties up to the nominal operation condition were examined.","PeriodicalId":285677,"journal":{"name":"Teion Kogaku (journal of The Cryogenic Society of Japan)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129659029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cryocooler (4)-Fundamental Review of Cryogenic Refrigerators- 低温制冷机(4)-低温制冷机的基础综述

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.42.74

Y. Matsubara

引用次数: 0

In-situ 法MgB2バルクの粒径支配因子と粒界ピンニング In-situ法MgB2散装粒径支配因子和粒界销

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.41.497

桂ゆかり, 明保山本, 功岩山, 滋堀井, 淳一下山, 光二岸尾

{"title":"In-situ 法MgB2バルクの粒径支配因子と粒界ピンニング","authors":"桂ゆかり, 明保山本, 功岩山, 滋堀井, 淳一下山, 光二岸尾","doi":"10.2221/JCSJ.41.497","DOIUrl":"https://doi.org/10.2221/JCSJ.41.497","url":null,"abstract":"We attempted to identify the predominant flux pinning center in in-situ-prepared polycrystalline MgB2 bulk superconductors. From microstructural observations, we succeeded in fabricating MgB2 bulks with systematically controlled grain sizes. It was found that grain size of the starting boron powder, nominal composition of Mg against B, heating temperature and holding time are the four grain-size determinants of MgB2 bulks. The grain size of B powder was found to determine the initial size of the MgB2 grains, while the heating temperature and nominal composition of Mg against B were found to determine the grain growth rate. In all series of samples, MgB2 bulks with smaller grain sizes exhibited higher irreversibility fields and higher pinning forces. We observed a strong relationship between the inverse of mean grain sizes and maximum pinning forces, indicating that grain boundary is the predominant pinning center in undoped MgB2 bulks. Moreover, carbon doping was found to increase the elementary pinning force at the grain boundary. This suggests that it is essential to develop a method to dope carbon into MgB2, without decreasing the density of the grain boundaries.","PeriodicalId":285677,"journal":{"name":"Teion Kogaku (journal of The Cryogenic Society of Japan)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129093122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Development of Bi-2223 Wires with a Carbonate Barrier for AC Use-Reduced AC Losses in Parallel Transverse AC Magnetic Fields- 碳酸盐阻挡层交流用Bi-2223导线的研制——减少平行横向交流磁场中的交流损耗

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.41.36

N. Ayai, K. Hayashi, N. Amemiya, K. Yasuda

引用次数: 2

Simple Heat-conduction and Thermoacoustic Self-sustained Oscillation Branches 简单热传导和热声自持续振荡分支

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.40.13

A. Tominaga

引用次数: 1

Recent Progress in the Development of YBCO HTS Power Cables YBCO高温超导电力电缆的研究进展

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.46.335

T. Ohkuma

{"title":"Recent Progress in the Development of YBCO HTS Power Cables","authors":"T. Ohkuma","doi":"10.2221/JCSJ.46.335","DOIUrl":"https://doi.org/10.2221/JCSJ.46.335","url":null,"abstract":"There are expectations for high-temperature superconducting (HTS) power cables as a compact cable with large capacity and low-loss power transmission. Recently, the stable manufacture of many long REBCO (RE = rare-earth element) tapes has been achieved. REBCO tapes have a high critical-current density, and the AC loss resulting from the parallel magnetic field is extremely small because of the thin-film structure of the superconducting layer. The basis of the M-PACC (Materials & Power Applications of Coated Conductors) project is to develop a process technology for fabricating REBCO tapes and promote development aiming toward the commercialization of superconducting cables using REBCO tapes. Two types of HTS cables are being developing as part of this project. These cables have superior transmission efficiency, lower loss and larger capacity than existing power cables. One is a 66 kV/5 kA three-core large-current cable and the other is a 275 kV/3 kA single-core high-voltage cable. There are several development targets. We examined factors such as AC loss, thermal characteristics of the cables under over-current and the optimum cable design. This paper provides an overview of the project and describes its progress.","PeriodicalId":285677,"journal":{"name":"Teion Kogaku (journal of The Cryogenic Society of Japan)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114117168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Visualization Techniques for Thermo-fluid Phenomena in Cryogenic Fluids 低温流体中热流体现象的可视化技术

Teion Kogaku (journal of The Cryogenic Society of Japan) Pub Date : 1900-01-01 DOI: 10.2221/JCSJ.43.67

T. Iida, M. Murakami, A. Nakano

引用次数: 0