Abstract: An inspection apparatus capable of suppressing degradation of oxide superconductors comprises a transformer including a flux-change detection coil and a flux transmission coil and formed of a first superconductor, an SQUID element magnetically connected to the flux transmission coil and formed of a second superconductor, a first indirect cooling section containing the flux transmission coil and the SQUID element, a second indirect cooling section including a first through hole, the flux-change detection coil winding around the first through hole, a vessel including a second through hole formed therein and located inside the first through hole, the vessel making, a sealed space, a space in which the transformer and the SQUID element are located, and a cooling section thermally connected to the first and second indirect cooling sections to cool the transformer and the SQUID element to a value not higher than the critical temperatures of the first and second superconductors.

Abstract: In a SQUID magnetometer, high resolution, a high slew rate, and a high dynamic range are achieved without using expensive circuit components having a large number of processing bits and enabling a high speed processing operation. A digital FLL circuit using a double counter system is provided. This circuit utilizes two or more counters, for example, a change range counter in a digital FLL for carrying out a processing operation at a high speed and a reproducing counter in a control/measuring computer. In addition, in the present invention, hysteresis characteristics having a 1?0 positive margin is used. That is, a change of a state of a magnetic flux is counted by means of a counter. At the time of this change, control is made so as to track a different channel between cases in which a magnetic flux increases and decreases, thereby stabilizing the control.

Abstract: In a SQUID magnetometer, high resolution, a high slew rate, and a high dynamic range are achieved without using expensive circuit components having a large number of processing bits and enabling a high speed processing operation. A digital FLL circuit using a double counter system is provided. This circuit utilizes two or more counters, for example, a change range counter in a digital FLL for carrying out a processing operation at a high speed and a reproducing counter in a control/measuring computer. In addition, in the present invention, hysteresis characteristics having a 1?0 positive margin is used. That is, a change of a state of a magnetic flux is counted by means of a counter. At the time of this change, control is made so as to track a different channel between cases in which a magnetic flux increases and decreases, thereby stabilizing the control.