Development of a High-Tc SQUID Cryo-System for the Measurement of a Remanent Magnetic Field of Rock

Saburo TANAKA  Ryouji SHIMIZU  Yusuke SAITO  Koichi SHIN  

IEICE TRANSACTIONS on Electronics   Vol.E83-C   No.1   pp.44-48
Publication Date: 2000/01/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Superconductive Devices and Systems)
Category: SQUIDs
High-Tc,  SQUID,  superconductor,  microscope,  rock,  remanent magnetic field,  

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A portable cryo-system using a high-Tc SQUID for the measurement of the remanant magnetic field of a rock specimen was designed and fabricated. The sensing surface of the SQUID faces upward in our system, although the system for bio-magnetics faces down. The SQUID is cooled by liquid nitrogen via a sapphire heat transfer rod. The total heat transfer of the system was measured by means of a boiling-off method and was found to be 1.65 W. It was demonstrated that the system can be operated for more than 17 hours without any maintenance such as filling with liquid nitrogen. The system was applied to the measurement of the remanent magnetic field distributions of rock samples cored from deep underground. We have successfully measured the distributions.