| Summary: | 碩士 === 國立清華大學 === 物理學系 === 105 === This thesis includes two sections. In the first section, we apply x-ray photon correlation spectroscopy(XPCS) to measure the lifetime in a dynamical equilibrium system. The scattered intensity from particles which float in the air or suspend in the liquid depends on the positions of which. In dynamical system, the scattered intensity fluctuates with time because the positions of the particles are changing constantly. By using the autocorrelation function, we can obtain the dynamic and the structure information of particles by analyzing the fluctuating intensity. In our study, there are two dynamical mechanisms that Co-doped CeO2 nano-particles are heated and illuminated by X-ray. When the system is in dynamical equilibrium, we measure the scattered intensity from the sample and drive the lifetime using the autocorrelation function. The second section is about using the multi-diffraction method to resolve the phase problem in x-ray diffraction experiment. The multi-diffraction method has been reported by Prof. Chang in 1982. In 1988, Dr. Tang proposed that the invariant phase can be determinated by analyzing he intensity profile of the multi-wave diffraction. We adopted two methods above to study the phase relationships of the structure factors of crystalline InSb. The divergence of the light source in the horizontal direction is also considered in the theoretical analysis to improve the fitting accuracy.
|
|---|
