Measuring instrument, electrical resistance elements and measuring system for measuring time-variable magnetic fields or field gradients

摘要

The invention relates to a measuring instrument for time-variable magnetix fluxes, or flux gradients, to electrical resistance elements, and to a measuring system comprising a measuring instrument or electrical resistance element according to the invention. The core component of the measuring instrument is a flux transformer composed of a base material which has a phase transition to the superconducting state. According to the invention, even when the base material is in the superconducting state, this flux transformer comprises at least one load region having electrical resistance that is other than zero for dissipating the electric energy in the conductor loop thereof. For this purpose, according to the invention the conductor loop and the magnetic field source are disposed in one plane and are typically photolithographically structured. The resistance elements according to the invention, having resistance values of ≦10−4Ω, are used as core components in the measuring instrument. According to the invention, measurement is possible in a broader frequency range, with less noise and with greater sensitivity than was possible with generic measuring instruments or measuring systems.

主权项

1. A measuring instrument for time-variable magnetic fields, or field gradients, comprising:
a flux transformer having a conductor loop comprising a base material, which has a phase transition to the superconducting state, for converting a time-variable magnetic flux, or flux gradient, into an electric current, and a magnetic field source that is fed by said conductor loop for converting the electric current into an auxiliary magnetic field; and a sensor for the auxiliary magnetic field, wherein the flux transformer, even when the base material is in the superconducting state, comprises at least one resistive region for dissipating the electric energy in the circuit, which comprises the conductor loop and the magnetic field source, the conductor loop and the magnetic field source being disposed in one plane, and at least one electrical resistance element which has an electric resistance between 10−11Ω and 10−5Ω or at least one tunnel contact at the resistive region.