| 摘要 |
<p>PURPOSE:To increase the detection sensitivity of a moving body by a method wherein the magnetic change of the moving body accompanied by the movement or presence thereof is grasped as the transition of a conductor from a superconductive state to a normally conductive state using a superconductor quantum interferometer when the presence or movement of the moving body such as a person is detected. CONSTITUTION:A loop is formed from a superconductor low in inductance and one or two Josephson junctions are prepared in said loop to constitute a superconductor quantum interferometer element 13 and a bias current is allowed to flow to said element to preliminarily bring the same to a state near the boundary of superconductivity and normal conductivity. When the magnetic flux crossing the loop is changed by the movement of a person or body in this state, a current for cancelling the magnetic flux flows to the loop and the element 13 is changed from a superconductive state to a normally conductive state and voltage is generated between both terminals of the element 13. When magnetic flux enters the loop, no current flows and the element 13 is returned to the superconductive state and no voltage is generated. By utilizing this theory, the presence or movement of a person is certainly known through a detection coil 9.</p> |
