BEPCⅡ高频屏蔽波纹管纵向耦合阻抗测量和数值计算
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29 11 2005 11
HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS
Vol.29,No.11
Nov.,2005
BEPC
*
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1( 100049)
2( 100084)
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(References)
1BEPC Design Report—Storage Rings:IHEP-BEPC -SB-03-3.2003.11(in Chinese)
(BEPC :IHEP-BEPC -SB-03-3.
2003.11)
2Sands M,Rees J.PEP-95,August,1974
3Hahn H.Phys.Rev.ST Accel.and Beams,2000,3:122001 4W ANG Guang-Wei.Ph.D Dissertation,1989(in Chinese) ( . ,1989)
5LENG Yong-Bin.Ph.D Dissertation,1999(in Chinese) ( . ,1999)
6HUANG Gang.Ph.D Dissertation,2001(in Chinese)
( . ,2002)
7Engen G F,Hoer C A.IEEE Transaction on Microwave Theory and Techniques,1979,MTT-27:987—993
8Foley M et al.Proc.of the PAC1993,3294
9Lambertson G R et al.Proc.of European Particle Accel.
Conf.Nice,France,1990.1049
10Hahn H.Phys.Rev.ST Accel.and Beams,2004,7:012001 11ZHOU Li-Juan.Heating Test of the RF-Shield Bellows for BEPC .Vacuum,2005,42(2):49(in Chinese)
( .BEPC . , 2005,42(2):49)
12The MAFIA Collaboration:MAFIA Manual Ver.4.106 (CST GmBH,Darmstadt,Germany,2001)
Longitudinal Coupling Impedance Measurements and Numerical Simulations of RF-Shielded Bellows for BEPC *
ZHOU De-Min1;1)WANG Jiu-Qing1HUANG Gang2ZHOU Li-Juan1
1(Institute of High Energy Physics,Chinese Academy of Sciences,Beijing100049,China)
2(Department of Engineer Physics,Tsinghua University,Beijing100084,China)
Abstract An impedance measurement system has been established to measure the longitudinal coupling impedance of vacuum components for the BEPC upgrade project(BEPC ).The measurement system is based on the traditional coaxial wire methods.The measurements are done in frequency domain taking advantage of the HP/Agilent microwave vector network analyzer8720ES.Two kinds of techniques,the TRL calibration and using a reference line,were investi-gated and applied to the practical measurements.This paper introduces this impedance measurement system and the results of the measurements.As a comparison,we also give the numerical simulations of the RF-shielded bellows for BEPC .
Key words accelerator,beam instabilities,impedance measurement,bellows,coaxial wire method。
