DIPAC2011 - List of Authors (Siemens, M.)

Paper	Title	Page
MOPD19	Button BPM Development for the European XFEL	83
	D. Lipka, B. Lorbeer, D. Nölle, M. Siemens, S. Vilcins DESY, Hamburg, Germany
	Button beam position monitors will be the main BPM type used to measure the electron beam position at the European XFEL. Two different kinds of buttons are necessary: one type will be installed in the acceleration modules of the cold linac and the other in the warm environment. The electro-magnetic design of the feedthrough for both types of buttons will be discussed. A comparison of the designed and measured RF properties will be presented. In addition to the usual RF properties, also the properties at cryogenic level will play a role. HOM power must not heat up the BPM feedthroughs, in order to keep the cryo load of an overall accelerator module low, and also to prevent damage due to large temperature gradients over the ceramics of the feedthrough. First measurements with beam at FLASH show good agreement of the measured signals with the expectation.

Paper

Title

Page

Button BPM Development for the European XFEL

83

D. Lipka, B. Lorbeer, D. Nölle, M. Siemens, S. Vilcins
DESY, Hamburg, Germany

Button beam position monitors will be the main BPM type used to measure the electron beam position at the European XFEL. Two different kinds of buttons are necessary: one type will be installed in the acceleration modules of the cold linac and the other in the warm environment. The electro-magnetic design of the feedthrough for both types of buttons will be discussed. A comparison of the designed and measured RF properties will be presented. In addition to the usual RF properties, also the properties at cryogenic level will play a role. HOM power must not heat up the BPM feedthroughs, in order to keep the cryo load of an overall accelerator module low, and also to prevent damage due to large temperature gradients over the ceramics of the feedthrough. First measurements with beam at FLASH show good agreement of the measured signals with the expectation.