【摘要】：現(xiàn)場(chǎng)X熒光測(cè)量技術(shù)作為一種現(xiàn)場(chǎng)、快速分析手段,在礦產(chǎn)資源勘查領(lǐng)域已經(jīng)得到較好地應(yīng)用,且效益顯著,但在油氣測(cè)井中的應(yīng)用國(guó)內(nèi)還鮮為報(bào)道,主要原因是以往的攜帶式X熒光分析儀不能夠直接測(cè)量硅(Si)、鋁(Al)、鎂(Mg)、鈉(Na)等輕元素。由于輕元素?zé)晒猱a(chǎn)額低,激發(fā)效率低、特征X射線(xiàn)能量低、探測(cè)效率很低,同時(shí)由于輕元素間的K系譜線(xiàn)能量十分接近,基體效應(yīng)影響嚴(yán)重等原因,很大程度的限制了野外輕元素X熒光分析研究。本文對(duì)X射線(xiàn)熒光分析中涉及的相關(guān)技術(shù)進(jìn)行了詳細(xì)的研究,這主要包括:不同材料吸收濾光片降低原級(jí)光譜本底的研究,基體效應(yīng)與校正研究,真空度對(duì)X射線(xiàn)熒光測(cè)量的影響的研究。其中重點(diǎn)研究了不同材料吸收濾光片降低原級(jí)光譜本底的研究。論文主要的研究?jī)?nèi)容有:(1)因?yàn)檩p元素特征X射線(xiàn)能量小,極易被空氣等介質(zhì)所吸收,不能被探測(cè)器所測(cè)量,所以論文采用真空裝置的設(shè)計(jì)最大程度增加元素特征X射線(xiàn)的透過(guò)率。結(jié)果表明:壓強(qiáng)在200pa時(shí),Na元素凈峰面積為2112,在標(biāo)準(zhǔn)大氣壓下,Na元素凈峰面積為590,提高了約為3.58倍。(2)探討了硅漂移室探測(cè)器(SDD)與Si-PIN探測(cè)器在能量分辨率、探測(cè)效率。選用對(duì)低能X射線(xiàn)探測(cè)效率高能量分辨率也高的新型SDD探測(cè)器提高探測(cè)器對(duì)低能X射線(xiàn)的靈敏度。(3)對(duì)于輕元素元素而言,選擇合適的激發(fā)源一直是個(gè)難題,通過(guò)對(duì)不同微型X光管的特性參數(shù)對(duì)比,選用了瑞士COMET公司設(shè)計(jì)的Edix-Ⅲ型X射線(xiàn)管。(4)根據(jù)X射線(xiàn)在物質(zhì)中的吸收規(guī)律,吸收濾光片能夠有效地改善微型X光管輸出譜線(xiàn)的能量分布,極大的降低低能部分的散射本底。論文用MCNP5方法仿真X光管濾光片對(duì)原級(jí)譜線(xiàn)的影響,分析了不同濾光片材料及厚度與X射線(xiàn)原級(jí)譜衰減的關(guān)系,得到不同濾光片對(duì)X射線(xiàn)譜的衰減規(guī)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，

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