A kind of cable structure of high-precision magnetic field measurement induction coil

Abstract

The invention discloses a cable structure of a high-precision magnetic field measuring induction coil. The cable structure is characterized in that the cable structure is formed by connecting two cables of different structures through a coaxial cable joint; a cable which is connected with one end of an induction coil probe and is enclosed in an accelerator magnet is a twisted-pair cable; a cable which is connected with one end of an integrator and is outside the accelerator magnet is a double-shielded coaxial cable; and the outer shield of the coaxial cable is connected with the casing of theintegrator and is grounded. According to the invention, two cable structures are combined to solve a long-standing problem in the field; the problem is that when the induction coil is placed in the magnet, the induction coil is connected with the integrator outside the magnet through a long cable, and a measurement signal is easily influenced by an electromagnetic interference signal of the connected cable; and the twisted-pair cable used alone and the coaxial cable used alone before combination cannot achieve the effect of combination.

Description

technical field [0001] The invention belongs to the technical field of magnetic field measurement, and in particular relates to a cable structure of an induction coil probe for high-precision magnetic field measurement. Background technique [0002] The movement of the induction coil in the magnetic field induces an electromotive force, and the change of the magnetic field can be obtained by measuring the integral value of the electromotive force over time. The induction coil method requires an integrator for magnetic field measurement. It is a high-precision magnetic field measurement method with a wide range of magnetic fields and is widely used in the magnetic field measurement of various magnets or accelerators. [0003] In the field of magnetic field measurement, sometimes the required relative accuracy of magnetic field measurement is better than 10 -4 , corresponding to the requirement that the measurement accuracy of the voltage induced by the induction coil be on t...

AI Technical Summary

Problems solved by technology

The induction coil is placed inside the magnet and needs to be connected to the integrator outside the magnet through a long cable. The measurement signal is easily affected by the electromagnetic interference signal of the connecting cable.

On the one hand, the partial cutting magnetic field of the cable in the magnet will generate additional electromotive force, which will cause measurement errors. On the other hand, the noise of the external alternating electric field will form a parasitic capacitance with the cable, and the vibration of the cable itself will also cause the charge accumulation on the cable , thus affecting the integrator measurement result

At present, there are two options for induction coil cables: (1) Use shielded twisted-pair wires, and the electromotive forces generated when the cables move in the magnetic field cancel each other out, but the movement of the shielding layer in the magnetic field will generate eddy currents, which will be transmitted to the ground through the integrator shell, A loop current is formed, which affects the measurement results; (2) The electric shielding coaxial line can better prevent the interference of vibration or external noise electric field, but the movement of the coaxial line in the magnetic field generates additional electromotive force

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