Thermal Stability of Butt Joint for CS Conductor in JT-60SA

Author

Takao, Tomoaki ; Kawahara, Yuki ; Nakamura, Kentaro ; Yamamoto, Yusaku ; Yagai, T. ; Murakami, H. ; Yoshida, Kenta ; Natsume, K. ; Hamaguchi, S. ; Obana, T. ; Takahata, K. ; Imagawa, S. ; Mito, T.

Author_Institution

Fac. of Sci. & Technol., Sophia Univ., Tokyo, Japan

Volume

24

Issue

3

fYear

2014

fDate

Jun-14

Firstpage

1

Lastpage

4

Abstract

Thermal stability for a butt joint of a central solenoid (CS) is experimentally and numerically estimated. The butt joint is fabricated using a strand bundle for the CS conductor, and the quench current of the butt joint is measured by changing the temperature of supercritical helium (SHe). The results show that even if the SHe flow slows to 50% of the rated flow, the temperature margin of the joint is 4 K, the butt joint is sufficiently stable. We also calculate the thermal stability of the butt joint by changing certain operating conditions. According to the simulation data, when connection resistance becomes high, from 2 to 5 nΩ, there is little change in the temperature margin. The experimental and numerical results suggest that the butt joint does not quench and can be operated with stability.

Keywords

conductors (electric); electric resistance; helium; solenoids; thermal stability; CS conductor; JT-60SA; SHe flow; butt joint; central solenoid; connection resistance; resistance 2 nohm to 5 nohm; simulation data; supercritical helium; temperature 4 K; temperature margin; thermal stability; Conductors; Helium; Joints; Numerical stability; Stability analysis; Temperature measurement; Thermal stability; Butt joint; JT-60SA; central solenoid coil; thermal stability;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2013.2284020

Filename

6615963