Advantages of a four-valve pulse tube cryocooler for high- T c sensor operation

• Published in: Cryogenics (Guildford) Vol. 37; no. 10; pp. 699 - 703
• Main Authors: Kaiser, G., Brehm, H., Wagner, R., Gerster, J., Wunderlich, S., Thürk, M., Seidel, P.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-1997
• Subjects: four-valve pulse tube cryocooler; high- T c SQUID operation; noise properties; four-valve pulse tube cryocooler; high- T c SQUID operation; noise properties
• ISSN: 0011-2275; 1879-2235
• DOI: 10.1016/S0011-2275(97)00056-8

In this contribution the results of our recent research on a special four-valve pulse tube cryocooler will be presented. We have performed control volume analysis in order to get information about the cooling power, the coefficient of performance and fundamental limitations of the ideal principle as a function of temperature, pressure ratio and the gas used for operation. High speed resistance thermometry at a prototype machine was used for measuring the temperature at the hot end and at the cold end of the pulse tube during operation for comparison with the predictions of theory. We will discuss a comparison about the possibility for continuous operation of a high-
T
c
SQUID gradiometer for biomagnetic applications on our prototype cryocooler and on a Gifford-McMahon cryocooler using the results of noise measurements recorded during cryocooler operation.