Development of SQUID Based Systems Cooled by GM/JT Cryocoolers

摘要

We have developed three types of SQUID based systems cooled by GM/JT cryocoolers. The first system has a single channel and was developed for biomagnetic measurement and non destructive test application. The unique feature of this system is minimal clearance between a detection coil and a specimen. The second system was designed for MCG and has 32-channel axial gradiometers placed on a flat surface. The third system was designed for MEG and has 61 channels of axial gradiometers arranged on a spherical surface that can conform to the human head. Here, we present our unique design features to cool the SQUIDs effectively and to reduce the noise from the cryocooler, and also present their performance.