Simulations and Experiments on Crosstalk of Multichannel SQUID Sensor Array for Magnetoneurography

For complex superconducting quantum interference device (SQUID) biomagnetic systems, such as multichannel magnetoneurography, channel crosstalk has been studied and solved to some extent, but the crosstalk effects of superconductors themselves are rarely considered. In this article, the crosstalk characteristics of superconducting coils induced by electromagnetic mutual inductance and Meissner effect were studied. Through simulation calculation, the main influence range of superconductivity diamagnetic effect is within 1 mm. When coil distance <0.5 mm, diamagnetic effect becomes the dominant factor of coil crosstalk. The simulation theory and results are verified by a three-coil crosstalk experimental system. In addition, one new calibration method for the crosstalk errors compensation is proposed and the crosstalk rate is successfully suppressed below 5% under the magnetoneurography measurement environment. It provides a way to analyze and solve the problem for the large complex systems with many dense superconductors.