Open AccessDynamic performance of the beam position monitor support at the SSRF
Author(s) -
Wang Xiao,
Cao Yun,
Du Hanwen,
Yin Lixin
Publication year - 2009
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049508028872
Subject(s) - beam (structure) , vibration , displacement (psychology) , finite element method , position (finance) , stability (learning theory) , synchrotron radiation , optics , modal analysis , cathode ray , structural engineering , beamline , acoustics , physics , materials science , mechanical engineering , computer science , electron , engineering , nuclear physics , psychology , finance , machine learning , economics , psychotherapist
Electron beam stability is very important for third‐generation light sources, especially for the Shanghai Synchrotron Radiation Facility whose ground vibrations are much larger than those for other light sources. Beam position monitors (BPMs), used to monitor the position of the electron beam, require a greater stability than other mechanical structures. This paper concentrates on an investigation of the dynamic performance of the BPM support prototype. Modal and response analyses have been carried out by finite‐element (FE) calculations and vibration measurements. Inconsistent results between calculation and measurement have motivated a change in the soft connections between the support and the ground from a ground bolt in the initial design to full grout. As a result the mechanical stability of the BPM support is greatly improved, showing an increase in the first eigenfrequency from 20.2 Hz to 50.2 Hz and a decrease in the ratio of the root‐mean‐square displacement (4–50 Hz) between the ground and the top of the support from 4.36 to 1.23 in the lateral direction. An example is given to show how FE analysis can guide the mechanical design and dynamic measurements ( i.e. it is not just used as a verification method). Similar ideas can be applied to improve the stability of other mechanical structures.