HTS-SQUID を用いた試料回転式小型磁化率計の開発と応用展開

This paper describes our newly developed compact rotating-sample magnetometer that uses a high-temperature superconductor, superconducting quantum interference device (HTS-SQUID). The system configuration of the developed magnetometer is described. The magnetic signal of pure water was measured, and the signal generated from pure water was successfully detected. In addition, the improvement of the new device was examined, and the signal-to-noise ratio increased by optimizing the measurement system. For practical application of the system, the silica gel moisture content was measured by comparing the magnetic signals obtained from several samples. The magnetic signal intensity increased with the silica gel moisture content. A new moisture content evaluation method using the change in magnetic signal that resulted from changing water content was proposed. Magnetic signal measurements during the magnetic relaxation of magnetic moments were investigated by changing the pick-up coil position. When the magnetic signal from pure water was measured with a time delay of 0.2 s after magnetization, a magnetic signal change could be detected. Therefore, the newly developed system can also measure magnetic relaxation phenomena.