Papers Published

  1. Bejan, A., Refrigerator-recirculator systems for large force-cooled superconducting magnets, Cryogenics (UK), vol. 17 no. 2 (1977), pp. 97 - 105 [0011-2275(77)90106-0] .
    (last updated on 2007/04/08)

    Forced-cooled superconductors are viewed as a promising alternative in the development of high field superconducting magnets for future fusion devices. The high current density cabled superconductor is protected against thermal instabilities by forcing (single phase) supercritical helium through the cable. The cryogenic cooling system for a forced-cooled superconducting magnet works as a refrigerator and a recirculator at the same time. The author discusses the conceptual design of the cooling systems for forced-cooled superconducting magnets with the overall objective of reducing the refrigeration costs. The general conclusion of this article is that economic cooling systems must employ efficient cold pump recirculators in which the large flow demanded by the forced-cooled superconducting magnet is confined to the cold end of the refrigerating column. If the liquid helium pump efficiency is less than 40%, systems employing elevated temperature compressors are more economic

    refrigeration;superconducting magnets;