Development and Characteristic Evaluation of High Resolution SQUID Magnetometer

Abstract

High resolution SQUID magnetometers had previously been developed which was designed for nerves, muscles, slices of brain tissue and small animals. In these SQUID system, diameters of the pickup coil were a few mm and the distances between the pickup coil and the outside surface of the dewer was a few mm. In this study, we developed a super high resolution SQUID magnetometer having higher spatial resolution than previous systems. In this system, diameter of the pickup coil is 200 µm, the distance between the pickup coil and the outside surface of the dewar is 800 µm. The typical system noise in the magnetic shielded room is 2.7pT/√Hz in the frequency from 1Hz to 10kHz. We discuss features of the measurement system and the spatial resolution of this SQUID system using a current source model. It can be discriminated extreme of magnetic field pattern obtained from the meander line of 500 µm interval.