摘要
In order to detect extremely weak magnetic signals,superconducting quantum interference device(SQUID)gradiometers are widely used to suppress environmental noise.A hardware SQUID gradiometer consists of a niobium gradio-antenna and an SQUID,which are coupled via an input coil.Here gradiometer imbalance may greatly reduce its noise suppression performance.The gradiometer balance depends on the geometrical forms of the antenna wound by niobium wire.We describe a simple method based on Faraday's law for the pre-calibration of the gradiometer balance at room temperature,before the gradiometer is set up.The pre-calibrating results are compared with the measured balance of an SQUID gradiometer system.This method may be used for sifting hardware gradiometers for multi-channel systems.
作者
张树林
刘扬波
刘明
王永良
孔祥燕
谢晓明
ZHANG Shu-Lin;LIU Yang-Bo;LIU Ming;WANG Yong-Liang;KONG Xiang-Yan;XIE Xiao-Ming(State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050;Graduate University of the Chinese Academy of Sciences,Beijing 1001903;Department of Electronic Science and Technology,University of Science and Technology of China,Hefei 230026)
基金
Supported by the National High-Tech Research and Development Program of China under Grant No 2008AA02Z308
and the Science and Technology Commission of Shanghai Municipality under Grant No 08JC1421800。
