Author: Schaelicke, A.     [Schälicke, A.]
Paper Title Page
WEPOW007 Status and Prospects of the BESSY II Injector System 2826
 
  • T. Atkinson, W. Anders, P. Goslawski, A. Jankowiak, F. Kramer, P. Kuske, D. Malyutin, A.N. Matveenko, A. Neumann, M. Ries, M. Ruprecht, A. Schälicke, T. Schneegans, D. Schüler, P.I. Volz, G. Wüstefeld
    HZB, Berlin, Germany
  • H.G. Glass
    BESSY GmbH, Berlin, Germany
 
  The BESSY II injector system consists of a 50 MeV Linac, installed in preparation for TopUp operation, and a 10 Hz fast-ramping booster synchrotron. The system provides injection efficiencies into the BESSY II storage ring well above 90 % . This contribution reports on the present status, measurements of energy acceptance and other essential beam parameters as well as studies on coupled-bunch-by-bunch instability. Requirements for BESSY-VSR and possible upgrade scenarios are discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW007  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOW009 The Bessy Vsr Project for Short X-Ray Pulse Production 2833
 
  • A. Jankowiak, W. Anders, T. Atkinson, H. Ehmler, A. Föhlisch, P. Goslawski, K. Holldack, J. Knobloch, P. Kuske, D. Malyutin, A.N. Matveenko, R. Müller, A. Neumann, K. Ott, M. Ries, M. Ruprecht, A. Schälicke, A.V. Vélez, G. Wüstefeld
    HZB, Berlin, Germany
  • A. Burrill
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of the Helmholtz Association
HZB has started the innovative project, BESSY VSR, to upgrade the 1.7 GeV synchrotron radiation source BESSY II. Its goal is to provide both 1.7 ps and 15 ps long, intense X-ray pulses simultaneously at all beam lines. These pulses are generated by enhanced longitudinal bunch focusing using superconducting 5-cell cavities operating at 1.5 GHz and 1.75 GHz. The resulting beating of the voltages creates alternating long and short buckets that can be custom filled. As a first major step, prototype superconducting cavities, initially only cooled to 4.4 K and thus operating at reduced voltage, will be installed into the BESSY II storage ring. Physical and technical aspects of this proposal where recently studied* and the results and project status are presented.
* A. Jankowiak, J. Knobloch for the BESSY VSR team, Technical Design Study BESSY VSR, doi:10.5442/R0001, Helmholtz-Zentrum Berlin (Germany), June 2015.
 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW009  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOW011 BESSY II Supports an Extensive Suite of Timing Experiments 2840
 
  • R. Müller, T. Birke, F. Falkenstern, K. Holldack, P. Kuske, A. Schälicke, D. Schüler
    HZB, Berlin, Germany
  • H.G. Glass, R. Ovsyannikov
    BESSY GmbH, Berlin, Germany
 
  The synchrotron light source facility BESSY II has put top-up and a fast orbit feedback (FOFB) into operation in 2013. Both operational improvements have matured and turned out to be especially beneficial for the advanced timing opportunities supported at BESSY. In combination with very tight injection efficiency requirements a thorough understanding of top-up injections under all operational conditions has been developed. Consequently arbitrary bunch currents can be dialed in and maintained on demand. In standard mode, a very pure camshaft bunch is available both in general for laser pump/X-ray probe and for pseudo single bunch experiments at the MHz chopper beamline. 3 constant high current bunches support the FEMTOSPEX slicing facility. An additional bunch can be resonantly excited and pulse picked via custom orbit bumps at 3 different undulator beamlines (PPRE). Due to the FOFB the classical timing modes "single bunch" and "low alpha" feature an attractive pointing stability.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW011  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOW012 Hardware Upgrades Improve the Reliability at BESSY II 2844
 
  • A. Schälicke, W. Anders, J. Borninkhof, V. Dürr, P. Goslawski, A. Hellwig, A. Heugel, H.-G. Hoberg, H. Hoffmann, A. Jankowiak, J. Kolbe, P. Kuske, G. Mielczarek, R. Müller, D. Pflückhahn, M. Ries, S. Rotterdam, M. Ruprecht, B. Schriefer, D. Simmering, H. Stein
    HZB, Berlin, Germany
 
  The synchrotron light source BESSY II is now in its second decade of operation. Already in 2013 both top-up and fast orbit feedback have been introduced into user operation. Currently, the facility is undergoing significant hardware upgrades in order to fulfill the increasing demands of its user community in terms of reliability, stability and flexibility. These include replacement of the DORIS cavities with EU HOM damped cavities, the upgrade of the RF transmitters to solid state amplifiers, implementation of the shifted waist optics for the new in-vacuum undulator, and refurbishment of the superconducting multi-pole wiggler. In this contribution status of BESSY II operation and the upgrade projects is reported.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW012  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR017 Resonance Island Experiments at BESSY II for User Applications 3427
 
  • P. Goslawski, J. Feikes, K. Holldack, A. Jankowiak, M. Ries, M. Ruprecht, A. Schälicke, G. Wüstefeld
    HZB, Berlin, Germany
  • R. Ovsyannikov
    BESSY GmbH, Berlin, Germany
 
  Beam storage close to a tune resonance (Qx = 1/3, 1/4) can generate resonance island buckets in the x,x' phase space providing a second stable island orbit winding around the standard orbit. Experiments with such an operation mode have been conducted at BESSY II and the Metrology Light Source (MLS)*,**. The two orbits are well separated, with good life time and stability. Such operation mode will offer additional operation flexibility and allows users to choose their radiation source point from one or the other orbit. It has the potential to fulfill simultaneously conflicting user demands, e.g., high vs. low beam current and single or few bunch filling vs. multibunch filling. We discuss the required beam optics setup and present successful measurements taken at photon beamlines at BESSY II.
* P. Goslawski et al., "Bunch Separation by Transverse Resonance Island Buckets", ESLS XXIII Workshop, 2015, Villigen, Switzerland.
** M. Ries et al., Proc. IPAC 2015, Richmond, USA, MOPWA021.
 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR017  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOW039 Measurements of the Lattice Modifications for the Cryogenic Undulator CPMU17 4031
 
  • J. Bahrdt, D.B. Engel, W. Frentrup, P. Goslawski, P. Kuske, R. Müller, M. Ries, M. Ruprecht, A. Schälicke
    HZB, Berlin, Germany
 
  A 2 mrad-canted double undulator system is in preparation as the wide energy range light source for the Energy Material in-situ Laboratory EMIL at the HZB storage ring BESSY II. The cryogenic undulator CPMU-17 is the hard X-ray device of the double undulator system. The soft X-ray undulator UE-48 is of the APPLE II type. It was installed and commissioned a few months ago, whereas the CPMU-17 is under fabrication. The CPMU-17 will employ a minimum magnetic gap of 5.5mm. Including a CuNi-foil for RF-shielding and geometric tolerances the free aperture is planned to be 5.0 mm. The BESSY II lattice has been modified locally in order to cope with the small gap device. The adapted betatron functions with a shifted vertical beam waist were measured and fitted with LOCO. The new optics agrees with the predicted performance. The free aperture at the installation place of the CPMU-17 was measured with four vertical scrapers. It is compatible with the projected minimum undulator gap. Finally, the measured injection efficiency with the new EMIL optics switched on is compatible with top-up operation (injection efficiency ≥ 90 %).  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW039  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)