模拟低频反馈系统的初步尝试

为了提高注入束流的积累，抑制由于注入系统误差引起较大的β残余振荡是非常有必要的。较系统地介绍了利用合肥光源逐圈测量（turn by turn）系统［１］，研究束流不稳定性，并给出了抑制注入β振荡的反馈系统设计原理和线路及初步实验结果。作为原理论证和预研，使用了一个相对简单的模拟滤波移相器对Kicker过程激发的β振荡进行反馈，得到了明显的对damping时间和振荡幅度的抑制作用，为以后低频和高频逐束团（bunch by bunch） 反馈系统研制和抑制束流的横向和纵向不稳定性的研究打下了良好的基础。

Primary attempt for simulation feedback system of low frequency

In order to improve the accumulation of the injected beam, it is very necessary to restrain β oscillation because of injected system error. This thesis systematically introduces the research for injection beam instability, the design principle and circuit of the feedback system for restraining the injected β oscillation of HLS using the turn by turn system［１］. Meanwhile, it also provides the result of preliminary experiments. As the proof of the theory and pre-study, we use a relatively simple analog filter and phase shifter to counteract the kicker course, which causes the β oscillation. From experiment result, it can be seen that the obvious restraining effect using the feedback system. All of these are the foundations of development for feedback system of bunch-by-bunch and lower