矿物材料现代测试技术3X荧光分析.ppt

矿物材料现代测试技术3X荧光分析
1 方法特点（4）
第二部分. X荧光成分分析
仪器外观：依据光源系统的不同、探测方式的不同，仪器的大小、形状有一定差异。
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1 方法特点（5）sive XRF uses a crystal to separate the various wavelengths: for every angle of incident radiation, the only wavelength reflected to the detector is the one that conforms to Bragg’s formula:
n = 2d sin 
where  is the wavelength of the x-ray radiation produced by the sample; d is a constant characteristic of every crystalline substance (. the x-ray crystal); and  is the angle on incidence of the x-radiation on the sample.
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4 WDS-XRF(2)
第二部分. X荧光成分分析
The crystals and their planes often used are as follow.
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4 WDS-XRF(3)
第二部分. X荧光成分分析
How to determine the wavelength:
Detector is rotating when doing the wavelength determination, also the crystal is rotating by half speed.
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4 WDS-XRF(4)
第二部分. X荧光成分分析
So, by changing the angle of the crystal, you can select any wavelength for specific elements of interest.
Different crystal can be used determine different elements. When doing measurement, we often need to change crystals for the various elements, finally we can yield results in any form desired: qualitative, ratio, quantitative, graphic,etc.
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4 WDS-XRF(5)
第二部分. X荧光成分分析
The relationship between the range of analyzing element and the crystals, and the 2 theta scanning range.
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4 WDS-XRF(6)
第二部分. X荧光成分分析
Analyzing Procedure:
Every element have a strongest X ray wavelength. In order to determine it, first we should measure the intensity of that wavelength.
For example, strongest Line and their 2θ position for Ni, Fe, & Ru, when detected by different crystal.
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4 WDS-XRF(7)
第二部分. X荧光成分分析
Analyzing Procedure:
In order to make the determination more accurate, we should also measure their accompanying peaks.
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4 WDS-XRF(8)
第二部分. X荧光成分分析
Analyzing
Procedure: