DESY, Hamburg
PETRA III is a new hard x-ray synchrotron radiation source which will be operated at 6 GeV with an extremely low horizontal emittance of 1 nmrad. This new facility is the result of a conversion of the existing storage ring PETRA II into a light source. The conversion comprises the complete rebuilding of one eighth of the 2304 m long storage ring, which will then house 14 undulator beam lines, the optical and experimental hutches, and the modernization and refurbishment of the remaining seven eighths. In addition two 100 m long damping wiggler sections have been installed which are required to achieve the small design emittance. Construction, installation and technical commissioning have been finished middle of March and then the commissioning with beam started. In this paper we present the results that have been achieved during commissioning with special emphasis on the role of diagnostic systems.
DESY, Hamburg
CERN, Geneva
RIKEN/SPring-8, Hyogo
PSI, Villigen
XFELs require high precision orbit control in the long undulator sections. Due to the pulsed operation of these systems the high precision has to be reached by single bunch measurements. So far cavity BPMs achieve the required performance and will be used at the European XFEL between each of the 116 undulators. Coupling between the orthogonal planes limits the precision of beam position measurements. A first prototype build at DESY shows a coupling between orthogonal planes of about -20 dB, but the requirement is lower than -40 dB (1%). The next generation Cavity BPM was build with tighter tolerances and mechanical changes, the orthogonal coupling is measured to be lower than -43 dB. This report discusses the various observations, measurements and improvements which were done.