Study of bunch length control by harmonic cavity for the coherent THz radiation

这项工作旨在研究能量相对较低的电子同步加速器中的纵向光束动力学，这将是一种能够在太赫兹波长范围内产生相干辐射的光源。作为在东北大学电子光科学中心1.2GeV电子同步加速器(STB环)中产生相干太赫兹辐射的实验准备工作的准备，还进行了采用宏粒子模型的模拟工作。虽然模拟的初步结果表明，可以获得强度不平凡的相干辐射，但由于其中包含相当多的不确定性，因此还需要继续进行更详细的工作。此外，为了提高进行实验所需的STB环的性能，还考虑了利用组合磁体将六极分量引入到环光学中的未来前景。

This work aims at studying the longitudinal beam dynamics in the electron synchrotron with the relatively lower energy, which would be a candidate for a light source to be able to generate the coherent radiation in the terahertz wavelength region. As setting up the preparation of the experiment as the demonstration to generate the coherent THz radiation in the 1. 2 GeV electron synchrotron (STB ring)at Electron Light Science Center, Tohoku University, a simulation work which employed the macro-particle model was also made. Although the preliminary results of the simulation showed that coherent radiation with a nontrivial intensity could be obtained, more detailed work should be continued because which included quite a few uncertainties. Furthermore, in order to improve the performance of the STB ring which is required to conduct the experiment, it is also considered as the future prospect to introduce the sextupole components in to the ring optics by employing the combined magnets.