SQUID SENSOR WITH STRONG MAGNETIC FIELD SHIELD AND SQUID SYSTEM UTILIZING SAME

摘要

PURPOSE: To block a transmission magnetic field to strengthen an applied field, miniaturize a device to prevent magnetic disturbance, and improve measuring accuracy, by providing a SQUID (superconducting quantum interference device) element part and a magnetic flux transformer within the empty part of a hollow magnetic shielding body. ;CONSTITUTION: A superconducting magnet 7 immersed in a liquid helium bath 6 is disposed within a vacuum insulating vessel 8, and a curve part 5 upward projected is provided in a bore part thereof to be set as a measuring chamber 5 of atmospheric pressure and room temperature. A SQUID element vessel 30 magnetically shielded by a magnetic shielding body 4 is hung down from a flange part 81, a coil holding pipe 20 is connected to the lower part thereof, and a magnetic field detecting coil 1 is provided in the tip thereof. A magnetic flux transformer is inserted in the holding pipe 20 together with a magnetic shielding body. In measuring, an object to be measured is installed in the chamber 5, the magnet 7 is excited by an outer power source 75, an abutting field stabilizer 79 is permanently magnetized in a fixed field strength, and a very small fluctuating field generated from the measured object is measured, controlled and analyzed by a SQUID element 3.;COPYRIGHT: (C)1994,JPO&Japio