• G. Kube, C. Behrens
  DESY, Hamburg
• W. Lauth
  IKP, Mainz

Luminescent screens are widely used for particle beam diagnostics, especially in transverse profile measurements at hadron machines and low energy electron machines where the intensity of optical transition radiation (OTR) is rather low. The experience from modern linac based light sources showed that OTR diagnostics might fail even for high energetic electron beams because of coherence effects in the OTR emission process. An alternative way to overcome this limitation is to use luminescent screens, especially inorganic scintillators. However, there is only little information about scintillator properties for applications with high energetic electrons. Therefore a test experiment has been performed at the 855 MeV beam of the Mainz Microtron MAMI (University of Mainz, Germany) in order to study the spatial resolution. The results of this experiment will be presented and discussed in view of scintillator material properties and observation geometry.

• G. Kube, J. Gonschior, U. Hahn, G. Priebe, H. Schulte-Schrepping, Ch. Wiebers
  DESY, Hamburg
• P. Ilinski
  BNL, Upton, Long Island, New York
• C.G. Schroer
  TUD, Dresden
• S. Weisse
  DESY Zeuthen, Zeuthen

PETRA III is the new 3rd generation hard X-ray synchrotron light source at DESY, operating at a beam energy of 6 GeV. Machine commissioning began in April 2009 and user operation starts in 2010. In order to achieve a high brilliance, damping wigglers with a total length of 80 m are installed to reduce the horizontal emittance down to an extremely low value of 1 nm rad. For a precise emittance online control, a dedicated diagnostics beamline was built up to image the beam profile with synchrotron radiation from a bending magnet in the X-ray region. The beamline is equipped with two interchangeable X-ray optical systems, a pinhole optic for standard operation and a high resolution compound refractive lens optic. In addition, the synchrotron radiation angular distribution can be exploited at high photon energies. In this presentation, first experience with the system will be reported.

• T. Aumeyr, G.A. Blair, S.T. Boogert, G.E. Boorman, A. Bosco
  JAI, Egham, Surrey
• K. Balewski, E. Elsen, V. Gharibyan, G. Kube, S. Schreiber, K. Wittenburg
  DESY, Hamburg

The PETRA-III Laser-wire, a Compton scattering beam size measurement system at DESY, uses an automated mirror to scan a Q-switched laser across the electron beam and is developed from the system previously operated at PETRA-II. This paper reports on recent upgrades of the optics, vacuum vessel and data acquisition. First beam profile measurements are also presented.