Heat-transfer Characteristics in Pressurized He II and the Metastabilization of Superconducting Coils

• Published in: TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan) Vol. 33; no. 6; pp. 397 - 402
• Main Authors: KOBAYASHI, Hisayasu, MURATA, Takaharu, FUJIMURA, Yoshio, SAKATA, Michitaka
• Format: Journal Article
• Language: English
• Published: CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN 1998
• Subjects: heat transfer; metastabilization; pressurized He II; subcooled He I layer
• ISSN: 0389-2441; 1880-0408
• DOI: 10.2221/jcsj.33.397

The heat transfer in ‘parallel channels’ filled with pressurized He II (He IIp) has been investigated to clarify the mechanism of the characteristics as compared to behavior in the Gorter-Mellink channel. The parallel channel with a rectangular cross-section consists of three insulator walls and a copper surface distributed along the channel length. Unlike the sudden rise in temperature in the G-M channel, the subcooled He I layer spread on the heated surface restrains abrupt transition at the critical heat flux, qλ, at which superfluidity is broken at the center of the parallel channel. The metastabilization of a superconducting coil cooled with He IIp has been also discussed by taking the specific heat transfer in the parallel channel into account.