| 摘要 |
PURPOSE:To measure a magnetic static characteristic and a dynamic characteristic of a measuring object with high accuracy by forming a spiral excitation use thin film coil on one surface of an electric insulating substrate, and forming a differential type thin film pickup coil of a first order or above, in its inside. CONSTITUTION:On one surface of an electric insulating substrate 1, and in the vicinity of its outside peripheral edge 1b, a spiral excitation use thin film coil 2 having a pair of terminals 2d, 2'd is formed centering around a prescribed center point O. In the inside of the coil 2, a differential type thin film pickup coil 3 of the first order or above having a pair of terminals 3a, 3c is formed so as to become a point symmetry against the center point O. Also, a liquid helium Dewar 4 is prepared, the substrate 1 is placed on the bottom part in the Dewar 4, and the coils 2, 3 become a superconductive state by liquid helium in the Dewar 4. The coil 3 is coaxial with the coil 2 in the center point O, and a magnetic flux of all the same quantity is inputted to a forward winding coil 3b and a reverse winding coil 3d, respectively, and accordingly, an influence of a magnetic field by the coil 2 is erased, and no noise is generated.
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