Unilateral nuclear magnetic resonance sensor and shielding structure of radio frequency coil

Abstract

The invention discloses a shielding structure of a radio frequency coil applied to a unilateral nuclear magnetic resonance sensor. The shielding structure comprises an aluminum casing used for accommodating a permanent magnet and a ferrite shielding board used for supporting the radio frequency coil, wherein the ferrite shielding board is arranged at an outer surface of one side of the aluminum casing and is between the aluminum casing and the radio frequency coil, the ferrite shielding board comprises a ferrite plate and a shielding layer formed by splicing multiple ferrite blocks, the adjacent ferrite blocks have gaps, the ferrite plate and the aluminum casing are oppositely arranged, and the shielding layer and the radio frequency coil are oppositely arranged. As the ferrite shielding board has relatively large magnetic conductivity and relatively small relative electrolytic leakage, so a radio frequency magnetic field generated by the radio frequency coil can be prevented from inducting relatively large vortex in the ferrite shielding board, a radio frequency magnetic field of the radio frequency coil at the aluminum casing side can be shielded by the shielding structure, so single-side shielding is realized, inducting the relatively large vortex in the aluminum casing can be prevented, and a magnetic field in a target area can be further enhanced. The invention further discloses the unilateral nuclear magnetic resonance sensor.

Description

technical field [0001] The invention relates to the technical field of nuclear magnetic resonance detection, in particular to a shielding structure of a single-sided nuclear magnetic resonance sensor and a radio frequency coil thereof. Background technique [0002] During the operation of the nuclear magnetic resonance sensor, in order to make the radio frequency coil generate a strong radio frequency magnetic field B1, it is necessary to pass into the radio frequency coil a radio frequency excitation with a resonant frequency of MHz level. If the alternating magnetic field generated by the radio frequency coil enters the permanent magnet, a strong eddy current effect will be generated in the permanent magnet, causing the permanent magnet to heat up. The secondary magnetic field generated by the eddy current is superimposed on the target area to cancel the original radio frequency magnetic field. Reduce the intensity of the radio frequency magnetic field, and due to the phas...

AI Technical Summary

Problems solved by technology

However, when the aluminum shell is shielded, it will also generate eddy currents and generate heat, which will affect the permanent magnets and reduce the strength of the RF magnetic field in the target area

Images