A Room-Temperature Pre-calibration Procedure for Gradiometer Sifting
ZHANG Shu-Lin1,2, LIU Yang-Bo1,2, LIU Ming3, WANG Yong-Liang1, KONG Xiang-Yan1, XIE Xiao-Ming1**
1State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 2Graduate University of the Chinese Academy of Sciences, Beijing 100190 3Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026
A Room-Temperature Pre-calibration Procedure for Gradiometer Sifting
ZHANG Shu-Lin1,2, LIU Yang-Bo1,2, LIU Ming3, WANG Yong-Liang1, KONG Xiang-Yan1, XIE Xiao-Ming1**
1State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 2Graduate University of the Chinese Academy of Sciences, Beijing 100190 3Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026
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.
Abstract：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.
[1] Romani G L et al 1982 Rev. Sci. Instrum. 53 1815
[2] Pizzella V et al 2001 Supercond. Sci. Technol. 14 R79
[3] Vrba J 1996 NATO ASI Series E: Appl. Sci. 329 127
[4] Becker W et al 1993 Physiol. Meas. 14 A45
[5] Clarke J and Braginski A I 2004 The SQUID Handbook (Weinheim: Wiley-VCH) pp 319–330
[6] He D F et al 1999 IEEE Trans. Appl. Supercond. 9 3684
[7] Lee S G et al 2007 IEEE Trans. Appl. Supercond. 17 3769
[8] Nordahn M A, Holst T and Shen Y Q 1999 Supercond. Sci. Technol. 12 946
[9] Dössel O et al 1991 IEEE Trans. Magn. 27 2797
2011, Vol. 28 
