A damping ring system which includes a small 1.1 GeV ring and two transport lines is introduced in CEPC linac in order to reduce the transverse emittance of positron beam at the end of linac and hence reduce the beam loss in the booster. This paper introduces the parameter choice and optics study of damping ring. The corresponding instability effect and IBS effect are also checked to make sure the design current and design emittance can be realized. Except for damping ring, two transport lines are needed to match the parameters between linac and damping ring. Both designs for energy compressor and bunch compressor including beam simulations are discussed in this paper.

中文翻译：

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CEPC阻尼环系统的设计与梁动力学

在 CEPC 直线加速器中引入了一个阻尼环系统，该系统包括一个 1.1 GeV 的小环和两条传输线，以降低直线加速器末端正电子束的横向发射率，从而减少助推器中的束流损失。介绍了阻尼环的参数选择和光学研究。还检查了相应的不稳定性效应和 IBS 效应，以确保可以实现设计电流和设计发射率。除阻尼环外，还需要两条传输线来匹配直线加速器和阻尼环之间的参数。本文讨论了能量压缩器和束压缩器的设计，包括梁模拟。