Losses of aluminium-stabilized superconducting conductors for Large Helical Device

Author

Sumiyoshi, F. ; Kanai, Y. ; Kawashima, T. ; Iwakuma, M. ; Mito, T. ; Takahata, K. ; Yanagi, N. ; Yanagi, N. ; Yamamoto, J.

Author_Institution

Fac. of Eng., Kagoshima Univ., Japan

Volume

28

Issue

1

fYear

1992

fDate

1/1/1992 12:00:00 AM

Firstpage

210

Lastpage

213

Abstract

The optimum design of aluminium-stabilized superconducting conductors used for the helical coil system of the Large Helical Device (LHD) project was investigated from the low loss point of view. A short sample conductor of about 50 cm long was used in the experiment. The loss measuring system originally fabricated is mainly composed of a superconducting split magnet of a race-track type and a superconducting transformer. The data of the AC loss observed in the frequency range from 0.1 Hz to 120 Hz show the existence of two peaks just as the analysis predicted. The peak at the lower frequency is the critical frequency of the inter-strand coupling time constant τ_c. The other peak at the higher frequency is the skin frequency of the normal metal around the strand bundle in the conductor. For the practical condition of the LHD corresponding to 0.1 Hz, the loss can be decreased by an increase in τ_c

Keywords

composite superconductors; fusion reactor materials; fusion reactor theory and design; magnetic leakage; stellarators; superconducting cables; superconducting magnets; 0.1 to 120 Hz; AC loss; Al; Large Helical Device; NbTi superconductors; NbTi-Al superconductors; critical frequency; helical coil system; inter-strand coupling time constant; loss measuring system; optimum design; skin frequency; Aluminum; Conductors; Frequency; Loss measurement; Magnetic analysis; Magnetic field measurement; Numerical analysis; Skin; Superconducting coils; Superconducting magnets;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.119847

Filename

119847