학술논문

Stability Margin of NbTi CIC Conductor for JT-60SA Equilibrium Field Coil
Document Type
Periodical
Source
IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 21(3):1991-1994 Jun, 2011
Subject
Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Conductors
Coils
Superconducting magnets
Temperature measurement
Thermal stability
Heating
Stability analysis
CICC
MQE
NbTi
quench
stability margin
Language
ISSN
1051-8223
1558-2515
2378-7074
Abstract
The equilibrium field (EF) coil conductors are designed with the NbTi cable in conduit (CIC) conductor because the maximum magnetic field of each conductor is up to 4.8 T for the EF-L conductor and 6.2 T for the EF-H conductor. The first EF conductor was manufactured and processed into the performance verification test sample. Then the performance verification tests had been operated before beginning the mass production. The current sharing temperature (Tcs) measurement tests and the quench tests were operated as the performance verification test to evaluate the Tcs and the minimum quench energy (MQE). The results of the Tcs measurement test indicate that both the Tcs of the EF-H conductor and the EF-L conductor are almost same as the expected value estimated by the strand characteristics. Additionally, the Tcs results satisfied the requirements of the EF coils, therefore the conductor design and the fabrication process are going well. The results of the quench test indicate that the EF conductors have enough stability marginuch as more than several hundred mJ/cc at the temperature margin of more than 0.5 K and the current of 20 kA. In addition, the supercritical helium (SHe) mass flow seldom influenced on the MQE. Thus the EF coil can be operated in stable condition even if the SHe mass flow will be decreased.