The New Beam Position Measurement System for the Desy Synchrotron

In the DESY synchrotron a new beam position measurement system has been installed to provide a fast, reliable and precise determination of the closed orbit. The Q-value (6.2 ... 6.3) of the synchrotron leads to a minimum of 25 stations to satisfy that requirement. Due to lack of available space in the straight sections, very short pick-up electrodes of permalloy-taped ring cores were chosen for the technical solution. The low average beam current in the synchrotron operating in the single bunch mode, requires a very sensitive system. This led to a narrow-band resonant device tuned to the revolution frequency of 947 ± 60 kHz followed by a "slow scan"-processor. For initial operation the output data are transferred to a printer. Later on a link to a computer will be established to provide a fast display of the measured closed orbit, and data for a process computer orbit correction program. First measurements and results with the new system are reported.