Temperature characteristics and thermal instability in composite ac superconductors

✍ Scribed by V.A. Altov; N.A. Kulysov; M.O. Lutset; Yu.M. Lvovsky

• Book ID: 103054389
• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 692 KB
• Volume: 22
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(82)90018-2

✦ Synopsis

The evolution of thermal instability in a superconducting system which is operating in a normal state can lead to severe damage (burnout) of the system. On the basis of numerical calculations, the temperature characteristics of a uniform, helium-cooled, ac superconductor operating in a normal state were analyzed. The system is thermally stable as long as the current is lower than the maximum equilibrium current i*, or its frequency is higher than the minimum equilibrium frequency ~2 ". Near the limiting values i* and ~2 ", a narrow region of parameters has been found where the conductor characteristics change drastically. According to the specific changes in the temperature characteristics in this region, the approach of dangerous values i* and ~2 " can be detected beforehand.

Peculiarities of the conductor's behaviour in this region are explained and the limiting equilibrium ac cycles described. The onset of thermal instability as the superconductor overheats is also studied.

The findings are well supported by experimental evidence.