为了提高低场磁共振成像系统的信噪比,提出了具有失谐电路的Bi2223带高温超导射频接收线圈.该线圈采用了电耦合方式传输超导谐振回路的磁共振信号,这种方式有利于进一步制成正交结构或相阵结构的超导接收线圈.为了防止趋肤效应降低超导接收线圈的性能,采用化学腐蚀的方法先将超导带的包套去掉,然后再制成超导主谐振电感.采用一种双探测线圈法对高温超导接收线圈和相同结构的常规铜线圈的Q值进行了测量,结果表明超导接收线圈比常规铜线圈的Q值约高一倍.
In order to improve the signal noise ratio (SNR) of low field MRI system, A Bi2223 tape High-Temperature Superconducting RF receiving Coil with detuning circuit has been designed. An electrical coupling mode is used in the coil design and this makes it very suitable for quadrature coil and phase array coil. To prevent degradation by the skin effect, the Ag sheath of Bi2223 tape was firstly removed by using a chemical method, and then the processed tape was wind on a frame to make the final superconducting resonance inductor. A double coil probe method is used to measure the quality factor (Q) of the RF Coils. Results show that the quality factor of HTS RF coils is 2 times that of copper coil with the same structure.