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.
DESY, Hamburg
The European XFEL is an X-ray free-electron-laser that is currently being built in Hamburg. It is organized as an international Project and will be a large scale user facility. Based on superconducting TESLA technology electron beams of high average power will be send to several undulator lines simultaneously to produce hard X-Rays with high average intensity and a peak brilliance by far superior to any 3rd generation light source. This paper will present the current status of the planning, the development and the prototyping process for this facility. It will cover as well as the BPM system, the other main diagnostic systems, like beam size measurements, charge, dark current and beam loss and protection systems.
