高頻磁場量測儀器-搜索線圈及其系統之發展

Development of search coil and its system

林其均(Chi-chun Lin)

指導教授 ： 郝玲妮

國立中央大學/地球科學學院/太空科學研究所/碩士(2012年)

摘要

本論文為台灣學界第一次發展太空規格搜索線圈磁力計(search coil)，及其校正系統。搜索線圈(search coil)磁力計為專門量測高頻磁場變化的磁場量測儀器，可量測高達數 kHz變化的磁場擾動，但無法量背景磁場的總值。一般在科學衛星上，例如THEMIS、DEMETER等衛星，會同時搭載可量測背景磁場的磁通閘(fluxgate)磁力與搜索線圈磁力計，以兩者互補來獲得精確的太空磁場資訊。本論文之目的為發展臺灣學界第一個自製太空規格之搜索線圈磁力計，並建構其基礎校正系統與校正程序。文章中將詳述搜索線圈的量測理論、校正原理、系統電路及後端資料擷取系統之設計。此自製發展搜索線圈磁力計之量測規格以偵測到地球磁層中非常微小的磁場擾動為目標，設定之量測範圍為10 Hz~ 3 kHz，在高頻時可達到pT等級的解析度。其等效感應磁場雜訊(Noise Equivalent Magnetic Induction; NEMI) 於10 Hz為4 pT/√Hz ，100 Hz 為0.35 pT/√Hz ，1 kHz為0.4 pT/√Hz。

關鍵字

搜索線圈 ； 高頻磁場量測

並列摘要

This thesis is to develop for the first time in Taiwan a search coil magnetometer and its calibrated system. The search coil magnetometer is specially designed for detecting AC magnetic field reaching several kHz, but not DC magnetic field. In many space science missions, such as THEMIS, DEMETER etc, the spacecraft carried both fluxgate magnetometer which can measure DC/AC magnetic field and search coil magnetometer, to obtain magnetic field information of space environments. The objective of this thesis is to develop the first search coil magnetometer with space specifications in the science community of Taiwan, and build the basic calibration system as well as calibrated standard procedures. In the thesis, I will introduce the theory of measurement and calibration, electric circuit of search coil. The purpose of our own designed search coil magnetometer is to detect very tiny perturbations in the earth’s magnetosphere and solar wind etc. The search coil covers the frequency bandwidth of 10Hz ~ 3kHz. It can reach pT level in high frequency and achieve the resolution NEMI (Noise Equivalent Magnetic Induction) of 4pT/√Hz of 10Hz, 0.35pT/√Hz of 100Hz, 1kHz of 0.4pT/√Hz.

並列關鍵字

search coil

參考文獻

[1]P. Ripka, Magnetic sensors and magnetometers. Norwood, MA: Artech House,2001, pp.57-65

[3] C. Coillot, J. Moutoussamy, R. Lebourgeois, S. Ruocco, and G. Chanteur, “Principle and Performance of a Dual-Band Search Coil Magnetometer: A New Instrument to Investigate Fluctuating Magnetic Fields in Space”, IEEE Sensor Journal, Vol. 10, NO.2, February 2010.

[4] H. C. Seran and P. Fergeaua) ,” An optimized low-frequency three-axis search coil magnetometer for space research”, Rev. Sci. Instrum. 76, 044502, 2005.

[5] Slawomir Tumanski, “Induction coil sensors—a review”, Meas. Sci. Technol. 18 (2007) R31–R46

[6] Eugene Paperno and Asaf Grosz, A miniature and ultralow power search coil optimized for a 20 mHz to 2 kHz frequency range, J. Appl. Phys. 105, 07E708 , 2009.