Browse > Article
http://dx.doi.org/10.9714/psac.2007.9.3.041

Numerical analysis about current non-uniformity in superconducting CICC (cable-in-conduit conductor) joint  

Lee, Sang-Il (한국과학기술원 원자력및양자공학과)
Jeong, Sang-Kwon (한국과학기술원 기계공학과)
Choi, Sung-Min (한국과학기술원 원자력및양자공학과)
Park, Kap-Rai (핵융합연구센터)
Publication Information
Progress in Superconductivity and Cryogenics / v.9, no.3, 2007 , pp. 41-45 More about this Journal
Abstract
This paper presents transport current non-uniformity in a joint for superconducting multistage cable-in-conduit conductor (CICC) and relaxation in the CICC. The joint is considered to have a current loop linked to an external magnetic field so that it becomes an emf voltage source. It is numerically analyzed using an electrical transmission line model. The inductive current in a resistive joint is compared to that of a non-resistive joint when the ramping field is applied vertically to the joints. Regarding the parameter values of the model. a full scale $Nb_3Sn$ CICC and a strand-to-strand (STS) joint for the toroidal field magnet of the KSTAR (Korea Superconducting Tokamak Advanced Research) device are referenced to. It is found that the resistive joint prevents the current from rising too much and enhances decaying the current when the ramping stops. The 'flattop' current is found to be proportional to the ramp rate of the field (dB/dt). The relaxation length, which is defined as the length within which the maximum induced current falls by 1/e. is found to saturate within 0.27m.
Keywords
current non-uniformity; relaxation length; cable-in-conduit conductor; joint; KSTAR.;
Citations & Related Records
연도 인용수 순위
  • Reference
1 L. Krempsky and C. Schmidt, 'Theory of 'supercurrents' and their influence on field quality and stability of superconducting magnets,' J. Appl. Phys., vol. 78, no. 9, pp. 5800-5810, 1995   DOI   ScienceOn
2 L. Bottura, M. Breschi, and M. Fabbri, 'Analytical solution for the current distribution in multistrand superconducting cables,' J. Appl. Phys., vol. 92, no. 12, pp. 7571-7580, 2002   DOI   ScienceOn
3 S. Kim and S. Jeong, 'Investigation on the stability of two-strand superconducting cable related with ramp-rate limitation,' Physica C, vol. 407, pp. 62-72, 2004   DOI   ScienceOn
4 L. Krempsky and C. Schmidt, 'Experimental verification of 'supercurrents' in superconducting cables exposed to AC-fields,' Cryogenics, vol. 39, no. 1, p p , 23-33, 1999   DOI   ScienceOn
5 S. Jeong and M. Takayasu , 'Rarnp-rate limitation experiment using induced current method. Part. 1: experimental results,' Cryogenics, vol. 42, no. 2, pp. 79-87, 2002   DOI   ScienceOn
6 N. Mitchell, 'Steady state analysis of non-uniform current distribution in cable-in-conduit conductors and comparison with experimental data,' Cryogenics, vol. 40, no. 2, pp, 99-116, 2000   DOI   ScienceOn
7 N. Amerniya, 'Overview of current distribution and re-distribution in superconducting cables and their influence on stability,' Cryogenics, vol. 38, no. 5, p p. 545-550, 1998   DOI   ScienceOn