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低原子序数元素能量色散X荧光仪的研制

The Research and Development of Low-Z Elements EDXRF Analyzer

【作者】 周建斌

【导师】 周蓉生;

【作者基本信息】 成都理工大学 , 矿产普查与勘探, 2008, 博士

【摘要】 X射线荧光光谱仪的不断完善和发展所带动的X射线荧光分析技术已被广泛用于冶金、地质、矿物、石油、化工、医疗、刑侦、考古等诸多部门和领域。本人从构成低原子序数元素能量色散X荧光仪的几个关键问题如探测器、分析电路、稳定高压电源、标准样品数据库、谱数据处理、系统软件设计以及整机的研制等入手,以国土资源部“十五”地质调查项目为依托、充分吸收已有X荧光分析技术的精华、积极引进IT技术、微电子技术以及数字信号处理技术,并针对已有X荧光分析技术存在的不足之处进行深入研究。完成了低原子序数元素能量色散X荧光仪的研制。在X荧光分析仪器中,X射线探测器的稳定性、能量分辨率、X射线发生器的稳定性以及“源-样-探”的几何位置关系是影响能量色散X荧光分析仪性能关键。本文论述的研制方案中,采用了电致冷Si-PIN半导体探测器,X光管作为X射线源,避免了同位素激发源可能对环境造成的污染;设计了真空测量系统,能显著提高分析仪器对低原子序数元素的探测效率;研制了采用ARM7微处理器作为核心控制芯片和以太网作为通信手段的多道脉冲幅度分析器,具有功耗低、信噪比高、稳定性好、通讯速度快等特点;设计了多道谱处理软件,能有效识别特征峰,可以进行标定测量,分析测量,长稳测试等工作,并采用了模式识别技术实现对样品进行自动分类测试,同时设计了Linux平台的数据处理软件适用于安全性可靠性更高的场合。由于低原子序数元素能量色散X荧光仪采用的电致冷半导体探测器能在工业现场或野外条件下工作,能达到室内(Si)Li半导体探测器的水平,并采用了微型X光管,以及成熟的谱处理技术,因此仪器在体积、重量、分析精度均能满足现场或实验室条件的分析测试要求。随着矿产开发、油气勘探的不断发展,以及世界环保要求的不断提高,该仪器将会在矿产勘探、油气勘探、选矿、冶炼、工业产品有害物质检测等领域发挥重要作用,带来巨大的社会效益和经济效益。

【Abstract】 Having been droved by the successive improvement and development of XRF spectrometer, XRF(X-Ray Fluorescence) Spectrometry is widely used in many departments and fields, such as metallurgy, geology, minerals, petroleum, chemical, medical, criminal investigation, archaeological and so on. From the key technical points of low-Z elements energy X-ray fluorescence Spectrometry such as detector, MCA, stable high power, database of standard samples, processing of the spectrum, design of system software and research of the whole instrument, the researches were carried on deeply according to the shortages of the technique of X-ray fluorescence Spectrometry existed. And the researches figured as support of "Five-Year Plan" Geological Survey scientific project of Ministry of Land and Resources, references of the key technique of X-ray fluorescence Spectrometry existed and intervening of information technique, micro-electronics technique and digital signal processing technique.The performances of EDXRF analyzer are mainly influenced by the stability and energy resolution of X-ray detector, the stability of X-ray generator and the geometric relationship of location of the Source-Sample-Detector in X-ray spectrometer. The research scheme used thermoelectrically cooled Si-PIN X-ray detector and took X-ray tube as the source of X-ray, which can effectively avoid the pollution of isotope excitation source to environment. Vacuum measurement system was designed to significantly improve the detecting efficiency of analytical instrument for low-Z elements. The MCA was developed in this paper. It was consist of the soul part of ARM7 MCU and the communication means by Ethernet, and had many features, such as low-power, high-SNR, excellent stability, high-speed data exchange, etc. Multi-channel spectrum processing software also was designed, which can recognizes characteristic peaks effectively and possesses functions of calibration, analysis and test of stability, etc. The automatically classification analysis of sample was implemented by Pattern-Recognition technique. At the same time, the software on Linux platform was developed for more safe and stable field.Low-Z elements Energy-XRF spectrometer, adopting electric refrigeration semiconductor detector, can be used in industrial or open field. It can reached the performances of indoor (Si)Li semiconductor detector. Micro X-ray tube was applied in this spectrometer and spectrum processing technology was mature, so in the condition of scene or experimental laboratory, this instrument can meets the need of analysis and measurement in many aspects, such as bulk, weight and analytical accuracy. With the development of exploiting minerals and oil gas, and the increasing request of world environment protection, this type of instrument may plays an important role in the area of mineral and oil exploration, mineral separating, smelt metal and detecting noxious constituent of manufactured products, and brings in huge economic benefit and social benefit yet.

  • 【分类号】O434.12
  • 【被引频次】17
  • 【下载频次】469
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