轻元素能量色散X荧光分析研究
发布时间：2019-04-13 18:50
【摘要】：现场X荧光测量技术作为一种现场、快速分析手段,在矿产资源勘查领域已经得到较好地应用,且效益显著,但在油气测井中的应用国内还鲜为报道,主要原因是以往的携带式X荧光分析仪不能够直接测量硅(Si)、铝(Al)、镁(Mg)、钠(Na)等轻元素。由于轻元素荧光产额低,激发效率低、特征X射线能量低、探测效率很低,同时由于轻元素间的K系谱线能量十分接近,基体效应影响严重等原因,很大程度的限制了野外轻元素X荧光分析研究。本文对X射线荧光分析中涉及的相关技术进行了详细的研究,这主要包括:不同材料吸收滤光片降低原级光谱本底的研究,基体效应与校正研究,真空度对X射线荧光测量的影响的研究。其中重点研究了不同材料吸收滤光片降低原级光谱本底的研究。论文主要的研究内容有:(1)因为轻元素特征X射线能量小,极易被空气等介质所吸收,不能被探测器所测量,所以论文采用真空装置的设计最大程度增加元素特征X射线的透过率。结果表明:压强在200pa时,Na元素净峰面积为2112,在标准大气压下,Na元素净峰面积为590,提高了约为3.58倍。(2)探讨了硅漂移室探测器(SDD)与Si-PIN探测器在能量分辨率、探测效率。选用对低能X射线探测效率高能量分辨率也高的新型SDD探测器提高探测器对低能X射线的灵敏度。(3)对于轻元素元素而言,选择合适的激发源一直是个难题,通过对不同微型X光管的特性参数对比,选用了瑞士COMET公司设计的Edix-Ⅲ型X射线管。(4)根据X射线在物质中的吸收规律,吸收滤光片能够有效地改善微型X光管输出谱线的能量分布,极大的降低低能部分的散射本底。论文用MCNP5方法仿真X光管滤光片对原级谱线的影响,分析了不同滤光片材料及厚度与X射线原级谱衰减的关系,得到不同滤光片对X射线谱的衰减规律。
[Abstract]:The field X-ray fluorescence measurement technology, as a kind of on-the-spot, rapid analysis method, has been well used in the field of mineral resources exploration with remarkable benefits, but its application in oil and gas logging has been rarely reported in China. The main reason is that the previous portable X-ray fluorescence analyzer can not directly measure the light elements such as Si (Si), Al (Al), mg (Mg), (Na) and so on. Because light element fluorescence yield is low, excitation efficiency is low, characteristic X-ray energy is low, detection efficiency is very low, at the same time, due to the very close energy of K family spectral line between light elements, the matrix effect is serious, and so on. The X-ray fluorescence analysis of light elements in the field is limited to a great extent. In this paper, the related techniques involved in X-ray fluorescence analysis are studied in detail. These include: the study of reducing the background of the original spectrum by absorption filters of different materials, the study of matrix effect and correction, and the research of matrix effect and correction. Study on the influence of vacuum degree on X-ray fluorescence measurement. The emphasis is placed on the study of reducing the background of the primary spectrum by absorption filters of different materials. The main contents of this thesis are as follows: (1) because the characteristic X-ray energy of light element is small, it is easy to be absorbed by the medium such as air, and can not be measured by the detector. Therefore, the design of vacuum device is used to increase the transmittance of characteristic X-ray elements to the maximum extent. The results show that when the pressure is 200pa, the net peak area of Na element is 2112, and the net peak area of Na element is 590 under standard atmospheric pressure. (2) the energy resolution and detection efficiency of (SDD) and Si-PIN detectors for silicon drift chamber detectors are discussed. (2) the energy resolution and detection efficiency of Si-PIN and Si drift chamber detectors are discussed. A new type of SDD detector with high energy resolution and low energy X-ray detection efficiency is used to improve the sensitivity of the detector to low energy X-ray. (3) for light elements, it is always difficult to select the appropriate excitation source. By comparing the characteristic parameters of different micro-X-ray tubes, the Edix- type 鈪，
本文编号：2457833
[Abstract]:The field X-ray fluorescence measurement technology, as a kind of on-the-spot, rapid analysis method, has been well used in the field of mineral resources exploration with remarkable benefits, but its application in oil and gas logging has been rarely reported in China. The main reason is that the previous portable X-ray fluorescence analyzer can not directly measure the light elements such as Si (Si), Al (Al), mg (Mg), (Na) and so on. Because light element fluorescence yield is low, excitation efficiency is low, characteristic X-ray energy is low, detection efficiency is very low, at the same time, due to the very close energy of K family spectral line between light elements, the matrix effect is serious, and so on. The X-ray fluorescence analysis of light elements in the field is limited to a great extent. In this paper, the related techniques involved in X-ray fluorescence analysis are studied in detail. These include: the study of reducing the background of the original spectrum by absorption filters of different materials, the study of matrix effect and correction, and the research of matrix effect and correction. Study on the influence of vacuum degree on X-ray fluorescence measurement. The emphasis is placed on the study of reducing the background of the primary spectrum by absorption filters of different materials. The main contents of this thesis are as follows: (1) because the characteristic X-ray energy of light element is small, it is easy to be absorbed by the medium such as air, and can not be measured by the detector. Therefore, the design of vacuum device is used to increase the transmittance of characteristic X-ray elements to the maximum extent. The results show that when the pressure is 200pa, the net peak area of Na element is 2112, and the net peak area of Na element is 590 under standard atmospheric pressure. (2) the energy resolution and detection efficiency of (SDD) and Si-PIN detectors for silicon drift chamber detectors are discussed. (2) the energy resolution and detection efficiency of Si-PIN and Si drift chamber detectors are discussed. A new type of SDD detector with high energy resolution and low energy X-ray detection efficiency is used to improve the sensitivity of the detector to low energy X-ray. (3) for light elements, it is always difficult to select the appropriate excitation source. By comparing the characteristic parameters of different micro-X-ray tubes, the Edix- type 鈪，
本文编号：2457833
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