A   B   C   D   E   F   G   H   I   K   L   M   N   O   P   Q   R   S   T   U   V   W  

ground-motion

Paper Title Other Keywords Page
MOPC049 Comparative Study of Vibration Stability at Operating Light Source Facilities and Lessons Learned in Achieving NSLS II Stability Goals site, lattice, storage-ring, electron 181
 
  • N. Simos, M. Fallier
    BNL, Upton, Long Island, New York
  • H. Amick
    Colin Gordon, Associates, San Bruno
  Understanding the correlation between storage ring vibration and electron beam oscillation is key in achieving the design beam parameters of a 3rd generation light source. Spectral properties of the vibration at the storage ring floor, in addition to amplitude, and its relation to the dynamic properties of the lattice govern the complex relation between lattice movement and beam jitter. Spectral characteristics are, in general, site-specific and motions exhibit spatial variability. To best describe the relationship between the ground motion field at the NSLS II site and the accelerator while quantifying the storage ring oscillations resulting from its interaction with the undisturbed site, field studies have been conducted at various light source facilities. By using the same metric data characterizing the achieved stability levels in operating light sources are generated and used in the assessment of the NSLS II stability which in turn linked to the specific site, subsurface and design characteristics. The paper summarizes the results of these comprehensive findings and presents an overall assessment of stability levels that can be achieved.

Work performed under the auspices of the US DOE.

 
 
MOPC050 Ground Motion Studies at NSLS II site, storage-ring, background, scattering 184
 
  • N. Simos, M. Fallier
    BNL, Upton, Long Island, New York
  • H. Amick
    Colin Gordon, Associates, San Bruno
  In 3rd generation light sources such as the 3 GeV NSLS II under design at BNL, strict requirements associated with vibration on the storage ring floor are imposed in order to minimize the jitter in the electron beam. Spectral characteristics storage ring vibration and dynamic properties of the ring lattice are controlling parameters. Ground motion at the NSLS-II site is characterized by a complex spectrum consisting of fast and slow motions stemming from natural and cultural sources. Cultural noise with frequencies higher than a few Hz has the potential of dramatically affecting the accelerator performance. In this study, an array of vibration measurements at the undisturbed NSLS II site has been made in order to establish the “green-field” vibration environment and its spectral characteristics. Its interaction with the NSLS II accelerator structure and the quantification of the storage ring vibration, both in terms of amplitude and spectral content have been assessed through a state-of-the-art wave propagation and scattering analysis. This paper focuses primarily on the wave propagation and scattering aspect as well as on the filtering effects of accelerator structural parameters.

Work performed under the auspices of the US DOE.

 
 
TUPC115 Vibration Stabilization for a Cantilever Magnet Prototype at the Subnanometer Scale controls, collider, linear-collider, instrumentation 1335
 
  • L. Brunetti, B. Bolzon, N. Geffroy, A. Jeremie
    IN2P3-LAPP, Annecy-le-Vieux
  • A. Badel, B. Caron, J. Lottin
    SYMME, Annecy-le-Vieux
  In the future linear colliders, the size of the beams is in the nanometer range, which requires stabilization of the final magnets before the interaction point. In order to guarantee the desired luminosity, an absolute displacement lower than 1/3 of the beam size, above a few hertz, has to be obtained. This paper describes an adapted instrumentation, the developed feedback loops dedicated to the active compensation and an adapted modelling able to simulate the behaviour of the structure. The obtained results at the subnanometer scale at the free end of a cantilever magnet prototype with a combination of the developed active compensation method and a commercial active isolation system are described.  
 
WEPC002 Analysis of Beam Orbit Stability and Ground Vibrations at the Diamond Storage Ring resonance, quadrupole, feedback, storage-ring 1980
 
  • R. Bartolini, H. C. Huang, J. Kay, I. P.S. Martin
    Diamond, Oxfordshire
  With the aim of understanding and improving the beam orbit stability at the Diamond storage ring we launched an extensive campaign of ground and magnets vibration measurements in order to identify the sources of ground vibration and how they affect the beam orbit stability through the girder resonances. We present here the results of the measurements performed during 2007 along with a discussion of the possible remedies and the implications for the orbit feedback systems.  
 
WEPC052 Achieving Stability Requirements for Nanoprobe and Long Beam Lines at NSLS II. A Comprehensive Study site, extraction, acceleration, brightness 2109
 
  • N. Simos, L. Berman, A. J. Broadbent, K. Evans-Lutterodt, M. Fallier, J. Hill
    BNL, Upton, Long Island, New York
  Driven by beam stability requirements at the NSLS II synchrotron a comprehensive study has been launched seeking to provide assurances that nanometer level stability at critical x-ray beam-lines is achievable, given the vibration environment at the selected site. Through this effort which represents the integration of an array of field measurements and a state-of-the-art model of wave propagation, the stability of special NSLS II beam-lines that push the envelope of beam size is quantified. In particular, the effects of ground vibration at the NSLS II site are studied both deterministically and stochastically to account for the stochastic nature of the disturbances arriving at the site and interact with the ring and the experimental lines. Validated numerical models are utilized in an effort to guide the design of sensitive lines. The objective is to both minimize vibration amplification as well establish a relative stability envelope between the beam extraction and imaging locations of the sensitive NSLS II beam-lines.