Transient heat transfer to a closed volume of He I and its influence on superconductor stability

✍ Scribed by C. Schmidt

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 519 KB
• Volume: 31
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(91)90060-a

✦ Synopsis

Transient heat transfer is one of the key parameters determining the stability of superconducting magnets. A large proportion of the experimental and theoretical work has been concerned with transient heat transfer from a solid surface to a liquid helium bath, whereas only few workers have investigated the case of a small, closed helium volume. The latter case is, however, the relevant boundary condition of cable-in-conduit conductors, which are often preferred for the construction of big magnets. In a small helium volume the transient heat input leads to a rapid rise in presssure which drastically reduces the heat removal capability of the coolant. Above the critical pressure of 2.3 bar the transient heat transfer is governed by thermal diffusion, as is the case for supercritical helium. This article describes some experimental work and theoretical approaches to this problem. The cases of liquid and supercritical helium are considered and some special examples of superconductor stability are discussed.