TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan)
Online ISSN : 1880-0408
Print ISSN : 0389-2441
ISSN-L : 0389-2441
Search
Advanced search
OR
Browse
Search
Volume 34, Issue 10
Displaying 1-5 of 5 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • [title in Japanese]
    Yoshitaka KIMURA
    1999 Volume 34 Issue 10 Pages 489
    Published: October 25, 1999
    Released on J-STAGE: February 26, 2010
    DOIhttps://doi.org/10.2221/jcsj.34.489
    JOURNAL FREE ACCESS
    Download PDF (215K)
  • Next-generation Mass Standard Using the Superconducting Magnetic Levitation Method
    Yukinobu MIKI, Fuyuhiko SHIOTA, Yusaku FUJII
    1999 Volume 34 Issue 10 Pages 490-497
    Published: October 25, 1999
    Released on J-STAGE: February 26, 2010
    DOIhttps://doi.org/10.2221/jcsj.34.490
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The present mass standard based on the prototype of the kilogram has some serious problems such as surface contamination and unrecoverablity in the case of damage or loss. Research on monitoring and finally replacing the present mass standard are therefore encouraged and some approaches have been proposed. In this article, the superconducting magnetic levitation method, which is one of the approaches that also makes use of the unique properties of superconductivity, is reviewed together with a brief description about mass and electric standards.
    View full abstract
    Download PDF (2281K)
  • Beginning of My Low Temperature Work and Early Days of Cryogenic Industry in Japan I've Heard and Seen
    Toyoichiro SHIGI
    1999 Volume 34 Issue 10 Pages 498-505
    Published: October 25, 1999
    Released on J-STAGE: February 26, 2010
    DOIhttps://doi.org/10.2221/jcsj.34.498
    JOURNAL FREE ACCESS
    Download PDF (1538K)
  • Introduction to Superconductivity
    Chapter 3: Phenomenological Theory
    Taiichiro OHTSUKA
    1999 Volume 34 Issue 10 Pages 506-514
    Published: October 25, 1999
    Released on J-STAGE: February 26, 2010
    DOIhttps://doi.org/10.2221/jcsj.34.506
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    On basis of the Meissner effect, which assures the reversibility of the normal-superconducting state transition, thermodynamical relations describing the difference in superconducting and normal states were derived in the preceding chapter. In this chapter, a two-fluid theory is described where the free electrons in the superconducting state are assumed to be a mixture of superelectrons that flow freely without resistance and normal electrons that have Ohm resistance. The theory is phenomological in that the property of the superelectron is based on experiment and the theory does not attempt to describe the nature and origin of the superelectrons.
    View full abstract
    Download PDF (1490K)
  • Stabilization Effects of Cu-ion Plating on Nb3Al Multifilamentary Wire Made Using the RHQT Process
    Akihiro KIKUCHI, Yasuo IIJIMA, Masao FUKUTOMI, Kiyoshi INOUE
    1999 Volume 34 Issue 10 Pages 515-523
    Published: October 25, 1999
    Released on J-STAGE: February 26, 2010
    DOIhttps://doi.org/10.2221/jcsj.34.515
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Nb3Al multifilamentary wire made by a rapid heating, quenching and transforming (RHQT) process shows not only 3-5 times higher Jc (4.2K), but also much lower strain sensitivity of superconductivity than that of commercialized (Nb, Ti)3Sn multifilamentary wire, and is therefore one of the most promising candidates as a next-generation superconductor. However, the Cu stabilization process is an unsolved key technology required to commercialize the RHQT-processed Nb3Al conductor. Because the RHQT process includes heat treatment at about 2, 000°C, which is much higher than the melting point of pure Cu, we must cover the Nb3Al wire with a Cu stabilizer after quenching. A stable Nb oxide layer is formed on the surface of the Nb3Al wire and prevents electrical and thermal conductivities between the Cu stabilizer and Nb3Al wire. We found that a 1μm thick Cu-ion plating on the Nb3Al wire removes the Nb oxide layer effectively. The Nb3Al wire, Cu-plated electrically with several tens of micrometers in thickness after being Cu-ion plated, shows improved Jc in lower fields and an increase in recovery current, which indicates the improved stability of the Nb3Al wire.
    View full abstract
    Download PDF (4359K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top