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

本工作的目的是研究电子同步加速器中相对较低能量的纵向束流动力学，这将是一个候选的光源，能够产生太赫兹波长范围内的相干辐射。作为演示实验的准备，在1。2GeV电子同步加速器（STB环）上，采用宏观粒子模型进行了模拟计算。虽然模拟的初步结果表明，可以获得具有非平凡强度的相干辐射，但更详细的工作还需要继续，因为它包含了相当多的不确定性。此外，为了提高STB环的性能，这是进行实验所需的，它也被认为是未来的前景，引入六极组件的环形光学通过使用组合磁铁。

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.