Study On Beam Polarization And It's Applications On Electron Storage Ring

An electron beam gets spontaneously polarized in the storage ring. Without considering depolarization effects, the equilibrium polarization could be as high as 92.38% for the electron beam in a storage ring. The spontaneous polarization property of the electron beam could be used to measure the electron beam energy and momentum compact factor, both linear and nonlinear components of the storage ring.The electron self-polarization effects, measurement of electron beam polarization in the context of a low-energy storage ring, and the resonant depolarization technique, have never been systematically studied in China. This dissertation provides a detailed and systematical investigation of these three topics using both Hefei electron storage ring and Duke storage ring.The first chapter of this thesis gives a brief history of electron spin and electron beam polarization and applications of the polarized beam in accelerators. The second chapter is about the theory of electron spin dynamics, electorn beam polarization, and also the simulation code SLIM. The simulation results of beam polarization in the storage rings are given at the end of this chapter. The third chapter is about theory and experiments related to the beam lifetime. The relationship between Touschek lifetime and beam polarization is given in detail, the experiments to measure momentum dynamic aperture and experiments to measure Touschek lifetime, together with the analysis that leads to the conclusion that Touschek lifetime is the dominant lifetime in the electron ring, are also discussed. The fourth chapter is about the experiments to measure electron polarization using Touschek lifetime. Using the 1.15 GeV beam in the Duke storage ring, the related experiments results and experimental methods are discussed. The fifth chapter is about how to use the spin resonant depolarization to measure the electron beam energy. The justifications for choosing proper experiment apparatus and experiment parameters are given in great detail. The control programs and experimental apparatus test results are presented at the end of this chapter. Due to the limitation of experimental conditions, we do not have experimental results on the electron beam energy measurement using the resonant depolarization technique.