应用被动式高次谐波腔改善合肥光源的束流寿命

J4 ›› 2011, Vol. 28 ›› Issue (5): 528-533.

应用被动式高次谐波腔改善合肥光源的束流寿命

刘广超吴丛凤王琳樊浩

中国科学技术大学国家同步辐射实验室, 安徽合肥 230029

收稿日期:2010-05-27 修回日期:2010-06-07 出版日期:2011-09-28 发布日期:2011-08-18
通讯作者: 吴丛凤：研究方向为加速器微波与高频技术以及新加速原理 E-mail:cfwu@ustc.edu.cn
作者简介:刘广超（1984-），研究生，研究方向为微波与高频技术。Email：xiaochao@mail.ustc.edu.cn
基金资助:
Work is supported by the National Nature Science Foundation of china （10675116）and by Hefei Light SourceⅡProject

Lifetime increase using a passive higher harmonic cavity for Hefei Light SourceⅡ

LIU Guangchao, WU CongFeng, WANG Lin, FAN Hao

National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China

Received:2010-05-27 Revised:2010-06-07 Published:2011-09-28 Online:2011-08-18
Supported by:
Work is supported by the National Nature Science Foundation of china （10675116）and by Hefei Light SourceⅡProject

摘要/Abstract

摘要：

高次谐波腔被用于同步辐射光源中拉长束团，降低束团密度，从而提高束流寿命，并且对光源亮度影响很小。理论推导了加入高次谐波腔之后的有关纵向束流动力学方程，计算了改造后的合肥光源（HLS-II）在加入三次谐波腔时最优条件下的寿命改善因子为2.9，束团长度为45.65mm；计算还表明束团在均匀填充模式下谐波腔中的束流负载效应对束团拉伸的影响可以忽略。经过大量数值模拟计算，优化设计了一个带有高次模阻尼的三次谐波腔。

关键词: 同步辐射光源, 束流寿命, 高次谐波腔, 束流负载效应, 高次模阻尼

Abstract:

Higher harmonic cavities are used in light sources to lengthen the bunch and increase the beam lifetime without effects on beam brightness. Some longitudinal beam dynamics equations with higher harmonic cavity are derived. Calculations for Hefei Light Source II(HLS-II) with a third harmonic cavity under the optimum conditions are presented. The results show that the factor of lifetime improvement is 2.9 and the bunch length is 45.65mm. The transient beam loading effect on the bunch length in harmonic cavity may be neglected for uniform fill of all rf buckets. Meanwhile, a third harmonic cavity with higher order modes damping was optimized through a large number of simulations.

Key words: synchrotron light source, beam lifetime, higher harmonic cavity, beam loading effects, higher order modes damping

中图分类号:

O432

刘广超吴丛凤王琳樊浩. 应用被动式高次谐波腔改善合肥光源的束流寿命[J]. J4, 2011, 28(5): 528-533.

LIU Guangchao, WU CongFeng, WANG Lin, FAN Hao. Lifetime increase using a passive higher harmonic cavity for Hefei Light SourceⅡ[J]. J4, 2011, 28(5): 528-533.