Evaluation of Temperature Rise Caused by AC Loss Due to Plasma Disruption in Joint of JT-60SA Poloidal Field Coil

Author

Nakamura, Kentaro ; Yamamoto, Yusaku ; Suzuki, Kenji ; Takao, Tomoaki ; Murakami, H. ; Natsume, K. ; Yoshida, Kenta

Author_Institution

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

Volume

25

Issue

3

fYear

2015

fDate

Jun-15

Firstpage

1

Lastpage

4

Abstract

Two kinds of joints (the lap and butt joints) for JT-60SA poloidal field coil are evaluated. We measured and analyzed AC losses of the joints for JT-60SA under a time-varying magnetic field, and based on the analytical AC loss, the temperature rise of the joints is estimated at the plasma disruption by using the FEM simulation software COMSOL Multiphysics. As a result, the maximum temperature of the lap joint is constant, on the other hand, the maximum temperature of the butt joint strongly depends on the mass flow of the supercritical helium. When the mass flow of the supercritical helium is 4 g/s and more in all the initial temperatures (4.2-7.0 K), the butt joint has a sufficient temperature margin at the plasma disruption. The obtained results become fundamental data to estimate the temperature margin of the coil.

Keywords

finite element analysis; liquid helium; plasma instability; superconducting coils; superconducting magnets; AC loss; FEM simulation software COMSOL multiphysics; He; JT-60SA poloidal field coil; analytical AC loss; butt joint; mass flow; plasma disruption; supercritical helium; temperature rise evaluation; time-varying magnetic field; Coils; Conductors; Joints; Loss measurement; Magnetic fields; Plasma temperature; AC loss; JT-60SA; central solenoid; plasma disruption;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2014.2364317

Filename

6933901