高能同步辐射光源中的耦合阻抗及束流集体效应研究

Study of Beam Coupling Impedance and Beam Collective Effect in High Energy Photon Source

在高能同步辐射光源(HEPS)的储存环中,由于真空盒尺寸较小、束团中电子密度较大,全环耦合阻抗将显著增加,束流集体效应成为限制机器性能的重要因素。本文基于解析理论和数值模拟程序对HEPS储存环耦合阻抗进行了逐元件建模,并对环中可能发生的束流集体效应进行了系统评估。建立了合理的阻抗模型,给出了不稳定性阈值和增长时间,并对关键的不稳定性问题提出有效的抑制措施。

In the storage ring of high energy photon source(HEPS),due to the small vacuum chamber and high bunch intensity,the total beam coupling impedance remarkably increases and the beam collective effect becomes the key limit of the machine performance.In this paper,the element-by-element model of beam coupling impedance for HEPS storage ring was carried out based on analytical theory and numerical simulation program,and a systematic estimation on the possible beam collective effect was carried out.A reasonable impedance model was established.The instability threshold and the growth time were given,and the effective suppression method for the key instability was presented.