Author: Milas, N.
Paper Title Page
THPC061 Comparison of Linear Optics Correction Means at the SLS 3032
 
  • M. Aiba, M. Böge, J.T.M. Chrin, N. Milas, T. Schilcher, A. Streun
    PSI, Villigen, Switzerland
 
  The experimental determination of linear optics is a fundamental prerequisite to achieving a high performance storage ring. In order to further enhance SLS performance and to simulataneously reveal the limitations of the various techniques, we perform a systematic study of linear optics optimization using various independent methods. These include an analysis of the orbit reponse (LOCO), turn-by-turn data, and the response of the tune, whose correction is accomplished using the standard SLS procedure of varying the quadrupole strengths. A comparison of results from these procedures, which use fully independent observables, provides us with a valuable cross-check. For example, the betatron phase advances between BPMs, which is independent of BPM calibration, confirms the optics correction as determined from LOCO. The linear optics are hence better optimized, and these procedures, LOCO in particular, further serve to expose any previously hidden mis-calibration of parameters e.g. from BPMs and corrector magnets. Systematic errors from turn-by-turn data could also be vastly reduced by a better synchronization of the BPM triggers with the electron beam.  
 
THPC062 SLS Vertical Emittance Tuning 3035
 
  • M. Böge, M. Aiba, N. Milas, A. Streun
    PSI, Villigen, Switzerland
  • S.M. Liuzzo
    INFN/LNF, Frascati (Roma), Italy
 
  To establish ultra-small vertical emittances (<1pmrad @2.86GeV) is one important aim of future linear collider damping ring optimization studies* at the SLS. By utilizing various correction techniques the SLS is already close to this goal with emittances of <2pm.rad @2.4GeV under the constraint of maintaining user operation conditions. One of the limiting contributions is the remaining spurious vertical dispersion etay of ~1.4mm which can be reduced by careful re-alignment and the application of dispersion-free steering techniques. The latter require orbit manipulations which are only partially compatible with the user operation mode. A first application of dispersion-free steering techniques demonstrates that etay can be reduced to <1mm at the expense of large orbit excursions which require a simultaneous betatron-coupling correction by means of skew quadrupoles in order to benefit in terms of a further reduction of vertical emittance. Therefore possible girder and magnet misalignments are analyzed in simulation which allows to localize the sources of etay and to eliminate them by re-alignment. Following this path the goal to achieve emittances close to 1pmrad is within reach.
* In January 2011 the EU-project TIARA (Test Infrastructure and Accelerator Research Area) started with contributions from the SLS as part of the SVET (SLS Vertical Emittance Tuning) work package WP6.
 
 
THPC095 Commissioning Status of the SwissFEL Injector Test Facility 3110
 
  • T. Schietinger, M. Aiba, S. Bettoni, B. Beutner, A. Falone, R. Ganter, R. Ischebeck, F. Le Pimpec, N. Milas, G.L. Orlandi, M. Pedrozzi, E. Prat, S. Reiche, C. Vicario
    PSI, Villigen, Switzerland
 
  The SwissFEL injector test facility at the Paul Scherrer Institute has been in operation since August 2010. Its primary goal is the demonstration of a high-brightness electron beam as it will be required to drive the SwissFEL main linac. The injector further serves as a platform for the development and validation of accelerator components needed for the SwissFEL project. We give an overview of recent commissioning activities at about 130 MeV beam energy, with particular emphasis on results from optics matching studies and emittance measurements, the latter obtained with different optics-based methods. A five-cell transverse-deflecting cavity allows studies of the longitudinal bunch charge distribution and slice emittance. Bunch length measurements will become the focus of interest after the installation of a magnetic compression chicane, currently scheduled for the summer of 2011.