Theoretical Research Of X-RAY Compound Refractive Lens And Its Application In Fluorescence Analysis

Micro X-ray fluorescence analysis system (μ-XRF) is widely used in practical applications. High performance optical components for focusing X-ray are the crucial part to realize the micro X-ray fluorescence system with the sub-microns spatial resolution. So the X-ray focusing elements become the research topic.In the first chapter, we briefly describe four X-ray focusing elements. To investigate the mechanism of X-rays interact with material, the mathematical expressions of Compton scattering coefficient and X-ray absorption coefficient are derived in terms of X-ray absorption over medium in the second chapter. The mathematical expressions of optical parameters, including focal length, transmission, numerical aperture, focal spot, strength gain, etc, are derived by electromagnetic field theory and matrix optical in the third chapter. Main works of this chapter focus on the numerical simulation for the optical performance with Compton scattering coefficient and photoelectric absorption coefficient. Analysis results show that Compton scattering coefficient has influence optical properties of compound refractive lens (CRL).Main works of the fourth chapter focus on the numerical computing simulation for the optical performance of capillary and CRL. Analysis results show that the X-ray CRL has the advantages in terms of focal spot size, transmittance, etc, when compared with capillary.The ladder-typed X-ray compound refractive lens, which is a new kind of X-ray compound refractive lens, is researched in chapter five. Its main parameter of optical properties are derived. The optical parameter of the ladder-typed X-ray compound refractive lens are calculated. The results are compared with the optical parameter of the ordinary paraboloid-shaped compound refraction lens. The Conclusions drawn in this chapter are the ladder-typed X-ray compound refractive lens can get the small focal spot and increase the light intensity of the battery of exit facet.A new kind of Micro XRF system adopting the ladder-typed compound refractive lens as its focusing element has been designed in chapter six. The system can improve the spatial resolution effectively and the detection efficiency.