Nuclear Techniques ›› 2019, Vol. 42 ›› Issue (12): 120101-120101.doi: 10.11889/j.0253-3219.2019.hjs.42.120101

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS •     Next Articles

A viscoelastic vibration reduction method of optical-elements for synchrotron radiation

Gang CAO1,2,Yi LI1,2,Hao LIANG1,Weifan SHENG1,2()   

  1. 1. Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-09-03 Revised:2019-10-23 Online:2019-12-10 Published:2019-12-18
  • Contact: Weifan SHENG E-mail:shengwf@ihep.ac.cn
  • About author:CAO Gang, male, born in 1993, graduated from Ludong University in 2015, doctoral student, focusing on vibration stability study of optical-elements for synchrotron radiation
  • Supported by:
    National Natural Science Foundation of China(11905243)

Abstract: Background

Vibration instability of optical-elements caused by ground micro-vibrations affects the position and focal length of the sample in the synchrotron beamline.

Purpose

This study aims to propose a scheme of employing viscoelastic dampers on beamline optical-elements for vibration reduction.

Methods

First of all, a viscoelastic damper was designed, and the coefficients of Prony series were obtained by nonlinear fitting of shear storage modulus and loss modulus of the viscoelastic materials by shared-parameters mode. Then, the dynamic properties of viscoelastic dampers were simulated by finite element software. Finally, this damper was applied to a long reflecting-mirror, and the harmonic response, transient dynamic analysis, and the static structural analysis of the supporting structure were carried out. In addition, the influence of the installation position of dampers on the damping effect were compared.

Results

Simulation results show that for the 1 μm vertical steady-state sweep excitation, the vertical displacement transmissibility of the mirror decreased by 35.2% (original position), 53.7% (closer to the edges), 32.4% (closer to the center) in the frequency range of 0~200 Hz, respectively. For the 1 μm vertical half-sine shock excitation with duration of 6.25 μs, the RMS values of 0.5 s after impact interference decreased by 70.8% (original position), 79% (closer to the edges), 59.7% (closer to the center), respectively.

Conclusions

The proposed viscoelastic damper can effectively reduce the influence of ground induced micro-vibrations on the mirror, and provide some guidelines for the vibration stability study of other optical-elements in synchrotron beamlines.

Key words: Micro-vibration, Viscoelastic dampers, Nonlinear fitting, Finite element analysis