Abstract
ABSTRACT Beam diagnostics plays an extremely important role in a Synchrotron light source. Undulator radiation is the major light sources of the third generation Synchrotron light sources. The high-resolution beam lines of the third generation Synchrotron light sources are considerably sensitive to the electron beam positions and profiles. Under the condition that fixed the undulator gap, many detecting systems with using the photon BPM for giving access to electron beam position had attained very high precision of 1 mm for years. However, the inevitable mixed synchrotron lights of the upstream and the downstream bending magnet radiation always caused a fatal alias signal for when the undulator gap was adjusting. This made the diagnostics devoid of accuracy and reliability. In this study, we primarily proposed an investigated adaptive approach of utilizing the Lloyd's mirror interference to overcome this difficulty. Our idea was to employ the characteristics of this optical interference method to distinguish the undulator light from the mixed bending magnet lights based on their distinctively different coherence qualities for that the latter is much better than the former. Then we further sought to the corresponding information of the beam size and the beam position through the visibility and the fringe density of the interference pattern. Theoretical developments and the associated simulations formulated the major parts of this thesis on inquiring the Lloyd's mirror interference of the undulator light source that is temporally coherent but spatially incoherent. This feature of the undulator light source was supposed to be conceptually analogous to our modified laser light prepared with degrading the relatively perfect spatial coherence of the primary laser light. By means of such identity, then we could implement the simulated interference experiments that are available for the general laboratory study at first. Herein, fundamentals of undulator theory were also been studied and some of the preliminary results of our simulations were demonstrated and discussed.