TY - JOUR
T1 - Design study on a 100-kA/20-K HTS cable for fusion magnets
AU - Hahn, Seungyong
AU - Song, Jungbin
AU - Kim, Youngjae
AU - Han, Ki Jin
AU - Lee, Haigun
AU - Iwasa, Yukikazu
AU - Chu, Yong
N1 - Publisher Copyright:
© 2002-2011 IEEE.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - Due to the > 100 times higher thermal stability of high temperature superconductor (HTS) than that of low temperature superconductor (LTS) and the capability of HTS to be operated at a liquid-helium-free temperature, an HTS cable is being considered a possible alternative to LTS for fusion magnets such as Toroidal Field (TF) coils in Tokamaks, and Helical coils in Stellarators. This paper presents a first-cut design of a 100-kA/20-K HTS cable, which could be an option for fusion magnets. Thermal behaviors of the cable were analyzed and compared quantitatively with those of a 100-kA/4.2-K Nb3Sn cable using the CryoSoft code THEA. In the paper, we demonstrated that the conventional concepts of the 'current sharing temperature (Tcs)' and the 'minimum quench energy (MQE)' may not be suitable for design and analysis of the HTS cable. Instead, 'thermal runaway temperature (TR)' and 'minimum runaway energy (MRE)' were proved to be more effective. Also, the post-quench temperature rise of the HTS cable, simulated by the THEA, was compared with that by the conventional analytic Z-function approach. The results demonstrate that the Z-function approach, proven to be effective for an LTS cable, may significantly overestimate the post-quench temperature rise of an HTS cable.
AB - Due to the > 100 times higher thermal stability of high temperature superconductor (HTS) than that of low temperature superconductor (LTS) and the capability of HTS to be operated at a liquid-helium-free temperature, an HTS cable is being considered a possible alternative to LTS for fusion magnets such as Toroidal Field (TF) coils in Tokamaks, and Helical coils in Stellarators. This paper presents a first-cut design of a 100-kA/20-K HTS cable, which could be an option for fusion magnets. Thermal behaviors of the cable were analyzed and compared quantitatively with those of a 100-kA/4.2-K Nb3Sn cable using the CryoSoft code THEA. In the paper, we demonstrated that the conventional concepts of the 'current sharing temperature (Tcs)' and the 'minimum quench energy (MQE)' may not be suitable for design and analysis of the HTS cable. Instead, 'thermal runaway temperature (TR)' and 'minimum runaway energy (MRE)' were proved to be more effective. Also, the post-quench temperature rise of the HTS cable, simulated by the THEA, was compared with that by the conventional analytic Z-function approach. The results demonstrate that the Z-function approach, proven to be effective for an LTS cable, may significantly overestimate the post-quench temperature rise of an HTS cable.
KW - Fusion magnet
KW - HTS cable
KW - Minimum runaway energy
KW - Thermal runaway temperature
UR - http://www.scopus.com/inward/record.url?scp=84921715548&partnerID=8YFLogxK
U2 - 10.1109/TASC.2014.2371068
DO - 10.1109/TASC.2014.2371068
M3 - Article
AN - SCOPUS:84921715548
SN - 1051-8223
VL - 25
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 3
M1 - 6957568
ER -