The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Simon, C. AU - Baboi, N. AU - Baldinger, R. AU - Baudrier, M. AU - Keil, B. AU - Lipka, D. AU - Luong, M. AU - Marinkovic, G. AU - Maurice, L. AU - Napoly, O. AU - Nölle, D. AU - Petrosyan, G. AU - Roggli, M. ED - Schaa, Volker RW TI - Design and Beam Test Results of the Reentrant Cavity BPM for the European XFEL J2 - Proc. of IBIC2016, Barcelona, Spain, Sept. 13-18, 2016 C1 - Barcelona, Spain T2 - International Beam Instrumentation Conference T3 - 5 LA - english AB - The European X-ray Free Electron Laser (E-XFEL) will use reentrant beam position monitors (BPMs) in about one quarter of the superconducting cryomodules. This BPM is composed of a radiofrequency (RF) reentrant cavity with 4 antennas and an RF signal processing electronics. Hybrid couplers, near the cryomodules, generate the analog sum and difference of the raw pickup signals coming from two pairs of opposite RF feedthroughs. The resulting sum (proportional to bunch charge) and difference signals (proportional to the product of position and charge) are then filtered, down-converted by an RF front-end (RFFE), digitized, and digitally processed on an FPGA board. The task of CEA/Saclay was to cover the design, fabrication and beam tests and deliver these reentrant cavity BPMs for the E-XFEL linac in collaboration with DESY and PSI. This paper gives an overview of the reentrant BPM sys-tem with focus on the last version of the RF front end electronics, signal processing, and overall system performance. Measurement results achieved with prototypes installed at the DESY FLASH2 linac and in the E-XFEL injector are presented. PB - JACoW CP - Geneva, Switzerland SP - 357 EP - 360 KW - electronics KW - cavity KW - linac KW - controls KW - cryomodule DA - 2017/02 PY - 2017 SN - 978-3-95450-177-9 DO - 10.18429/JACoW-IBIC2016-TUPG17 UR - http://jacow.org/ibic2016/papers/tupg17.pdf ER -