BEPCⅡ电子环寄生模损失测量

王洪磊; 王牧源; 杨际森; 沙鹏; 林海英; 马强; 王群要; 米正辉; 戴建枰; 孙毅; 王光伟; 潘卫民

doi:10.11884/HPLPB201931.190064

BEPCⅡ电子环寄生模损失测量

doi: 10.11884/HPLPB201931.190064

王洪磊^{1, 2,},
王牧源²,
杨际森^{1, 2},
沙鹏²,
林海英²,
马强²,
王群要²,
米正辉²,
戴建枰^{1, 2},
孙毅^{1, 2},
王光伟²,
潘卫民^{1, 2}

1.
中国科学院大学, 北京 100049
2.
中国科学院粒子加速物理与技术重点实验室, 北京 100049

基金项目:

国家重点研发计划项目 2016YFA0400400

详细信息

作者简介:
王洪磊(1990-), 男, 博士研究生, 从事加速器高频技术研究, hlwang@ihep.ac.cn

中图分类号: TL594
计量
- 文章访问数: 1211
- HTML全文浏览量: 278
- PDF下载量: 54
- 被引次数: 0
出版历程
- 收稿日期: 2019-03-07
- 修回日期: 2019-04-10
- 刊出日期: 2019-08-15

Parasitic mode loss measurement in BEPCⅡ e^- ring

Wang Honglei^{1, 2
,},
Wang Muyuan²,
Yang Jisen^{1, 2},
Sha Peng²,
Lin Haiying²,
Ma Qiang²,
Wang Qunyao²,
Mi Zhenghui²,
Dai Jianping^{1, 2},
Sun Yi^{1, 2},
Wang Guangwei²,
Pan Weimin^{1, 2}

1.
University of Chinese Academy of Sciences, Beijing 100049, China
2.
Key Laboratory of Particle Acceleration Physics and Technology, Chinese Academy of Sciences, Beijing 100049, China

摘要

摘要: BEPCII在设计阶段从束流不稳定性和寄生模损失角度对阻抗提出了限制，但在BEPCII运行中寄生模损失是影响高流强稳定运行的因素之一。针对BEPCII电子环的寄生模损失进行了测量，主要是基于同步相移随流强的微小变化、束流功率测量和高阶模吸收器的功率。测量结果表明：两种方法对比测量全环寄生模损失，结果重复可信，且全环寄生模损失是超导腔寄生模损失的4~5倍。
- 寄生模损失 /
- 同步相移 /
- 束流功率 /
- 高阶模
Abstract: In the design phase of BEPCII, the impedance is limited in terms of beam instabilities and parasitic mode loss. However, the parasitic mode loss has been one of the unfavorable factors affecting high beam current operation of BEPCII. This paper describes a measurement of the parasitic mode loss in BEPCII e^- ring, which is based on a small change of synchronous phase shift with beam current, the beam power measurement and the power of higher order mode absorber. The measurement results with two different methods of the total parasitic mode loss are repetitive and reliable. Moreover, the total parasitic mode loss of e^- ring is 4-5 times as large as the parasitic mode loss of the superconducting cavity.
- parasitic mode loss /
- synchronous phase shift /
- beam power /
- higher order mode

HTML全文

图 1 同步相位测量装置

Figure 1. Experimental setup for the synchronous phase measurement

下载: 全尺寸图片幻灯片

图 2 同步相移与腔压的关系

Figure 2. Synchronous phase shift vs RF voltage

下载: 全尺寸图片幻灯片

图 3 同步相移与流强的关系

Figure 3. Synchronous phase shift vs beam current

下载: 全尺寸图片幻灯片

图 4 高频功率测量原理

Figure 4. Scheme of RF power measurement

下载: 全尺寸图片幻灯片

图 5 束流功率和损失能量与流强的关系

Figure 5. Beam power and energy loss vs beam current

下载: 全尺寸图片幻灯片

图 6 超导腔示意图

Figure 6. Schematic diagram of superconducting cavity

下载: 全尺寸图片幻灯片

图 7 束流下降过程超导腔高阶模功率和损失参数测量

Figure 7. HOM power and loss factor measurement of SC cavity during beam decay

下载: 全尺寸图片幻灯片

表 1 测量结果

Table 1. Results of measurement

E/GeV	I_b/mA	bunch	U_s/keV	σ_l0/mm	V_c/MV	U_s/keV(measured)		U_pm/keV(measured)
E/GeV	I_b/mA	bunch	U_s/keV	σ_l0/mm	V_c/MV	phase	power	phase	power
1.55	600	82(103, 112)	52.8	10.81	1.48	53.6±1.3	51.3±0.9	15.5	12.9
Note: “phase” represents synchronous phase shift measurement method, “power”represents beam power measurement method

下载: 导出CSV

参考文献(10)

[1]	Farias R H A, Lin Liu, Rodrigues A R D, et al. Oscilloscope measurement of the synchronous phase shift in an electron storage ring[J]. Physical Review Special Topics—Accelerators and Beams, 2001, 4: 072801.
[2]	Podobedov B, Siemann R. New apparatus for precise synchronous phase shift measurements in storage rings[J]. Physical Review Special Topics—Accelerators and Beams, 1998, 1: 072801. doi: 10.1103/PhysRevSTAB.1.072801
[3]	Bartolini R, Fielder R T, Thomas C A. Loss factor and impedance analysis for the diamond storage ring[C]//Proceedings of the 4th International Particle Accelerator Conference. 2013.
[4]	Tavares P F, Fitterer M, Hiller N, et al. Beam coupling impedance measurements at the ANKA electron storage ring[C]//Proceedings of the first International Particle Accelerator Conference. 2010.
[5]	张闯, 马力. 北京正负电子对撞机重大改造工程加速器的设计与研制[M]. 上海: 上海科学技术出版社, 2015. Zhang Chuang, Ma Li. Design and development of accelerator for major upgrade project of the Beijing Electron-Positron Collider. Shanghai: Shanghai Science and Technology Press, 2015
[6]	王娜, 于程辉, 王建力, 等. BER异常高次模分析[C]//北京正负电子对撞机第十八届年会会议文集. 2013. Wang Na, Yu Chenghui, Wang Janli, et al. BER abnormal high order mode analysis//Proceedings of the 18th Annual Meeting of the Upgraded Beijing Electron Positron Collider. 2013
[7]	Belomestnykh S, Hartung W, Kirchgessner J, et al. Comparison of the predicted and measured loss factor of the superconducting cavity assembly for the CESR upgrade[C]//Proceedings Particle Accelerator Conference. 1995.
[8]	赵丹阳. 高精度幅相检测技术的研究及其在BEPCⅡ中的应用[D]. 北京: 中国科学院高能物理研究所, 2015. Zhao Danyang. Development of high accuracy amplitude and phase detection and application to BEPCⅡ. Beijing: Institute of High Energy Physics of Chinese Academy of Sciences, 2015
[9]	王牧源. BEPCⅡ数字低电平系统及其应用[D]. 北京: 中国科学院高能物理研究所, 2018. Wang Muyuan. BEPCⅡ digital low level RF system and its application. Beijing: Institute of High Energy Physics of Chinese Academy of Sciences, 2018
[10]	李勇, 王理, 段哲, 等. BEPCⅡ储存环对撞模式束团长度测量[C]//北京正负电子对撞机第十七届年会会议文集. 2012. Li Yong, Wang Li, Duan Zhe, et al. Bunch length measurement of BEPCⅡ storage ring on collision mode//Proceedings of the 17th Annual Meeting of the Upgraded Beijing Electron Positron Collider. 2012