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Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2017, Vol. 28 ›› Issue (8): 108 doi: 10.1007/s41365-017-0259-y

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS • Previous Articles     Next Articles

Improving Touschek lifetime and synchrotron frequency spread by passive harmonic cavity in the storage ring of SSRF

Thanapong Phimsen1,2, Bo-Cheng Jiang1, Hong-Tao Hou1,Zhen-Tang Zhao1,2, et al   

  1. 1 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Zhangjiang Campus, Shanghai 201800, China
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Supported by:

    Supported by the National Key Research and Development Program of China (No. 2016YFA0402001).

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Thanapong Phimsen, Bo-Cheng Jiang, Hong-Tao Hou, Shun-Qiang Tian, Man-Zhou Zhang, Qing-Lei Zhang, Zhen-Tang Zhao. Improving Touschek lifetime and synchrotron frequency spread by passive harmonic cavity in the storage ring of SSRF.Nuclear Science and Techniques, 2017, 28(8): 108     doi: 10.1007/s41365-017-0259-y

Abstract:

Beam lifetime of a synchrotron is dominated by Touschek scattering. In the beamline Phase II project of Shanghai synchrotron radiation facility, a passive third harmonic cavity is to be installed for bunch lengthening and instability suppressing. In this paper, the beam dynamics of the cavity is investigated. The parameters of passive operation are optimized to cancel the slope of RF voltage and lengthen the bunches. The Touschek lifetime increases are estimated for optimum and non-optimum voltage flattening. A tolerance of the operation is studied in case that there is a shift on detuning angle. The effect caused by reduction in harmonic voltage generated by lengthened bunch distribution is also estimated using iteration method. An increase in synchrotron frequency spread due to nonlinearity of the voltage giving to the bunch is found by using tracking simulation. This spread can help in damping coupled bunch instability through Landau damping.

Key words: Landau damping, Passive harmonic cavity, SSRF