IBIC2012 - List of Authors (Simon, C.S.)

Paper	Title	Page
MOPA15	New Electronics Design for the European XFEL Re-entrant Cavity Monitor	83
	C.S. Simon CEA/DSM/IRFU, France N. Baboi DESY, Hamburg, Germany R. Baldinger, B. Keil, R. Kramert, G. Marinkovic, M. Roggli, M. Stadler PSI, Villigen PSI, Switzerland
	About one third of the beam position monitors (BPMs) in the European XFEL (E-XFEL) cryomodules will be re-entrant cavities. The BPM mechanics and Radio-Frequency front-end (RFFE) electronics are developed by CEA/Saclay. Two RFFEs and a digital back-end with two ADC mezzanines are integrated into a compact standalone unit called MBU (modular BPM unit) developed by PSI. The signal processing uses hybrids and a single stage downconversion to generate the signals sum and delta. Every RF/analog component of the re-entrant BPM electronics has been simulated with a Mathcad model and tested independently on test benches. The very low Q of the cavity monopole mode allows the new electronics to filter this mode at the dipole mode frequency and an IQ demodulation for delta and sum channels allow the digital back-end to determine the sign of the beam position just by comparing the phases of the channels, independently of beam arrival time jitter and external reference clock phase. This paper describes the design and architecture of a new re-entrant BPM electronics, including results of beam tests at FLASH that were performed to validate the chosen design.

Paper

Title

Page

New Electronics Design for the European XFEL Re-entrant Cavity Monitor

83

C.S. Simon
CEA/DSM/IRFU, France
N. Baboi
DESY, Hamburg, Germany
R. Baldinger, B. Keil, R. Kramert, G. Marinkovic, M. Roggli, M. Stadler
PSI, Villigen PSI, Switzerland

About one third of the beam position monitors (BPMs) in the European XFEL (E-XFEL) cryomodules will be re-entrant cavities. The BPM mechanics and Radio-Frequency front-end (RFFE) electronics are developed by CEA/Saclay. Two RFFEs and a digital back-end with two ADC mezzanines are integrated into a compact standalone unit called MBU (modular BPM unit) developed by PSI. The signal processing uses hybrids and a single stage downconversion to generate the signals sum and delta. Every RF/analog component of the re-entrant BPM electronics has been simulated with a Mathcad model and tested independently on test benches. The very low Q of the cavity monopole mode allows the new electronics to filter this mode at the dipole mode frequency and an IQ demodulation for delta and sum channels allow the digital back-end to determine the sign of the beam position just by comparing the phases of the channels, independently of beam arrival time jitter and external reference clock phase. This paper describes the design and architecture of a new re-entrant BPM electronics, including results of beam tests at FLASH that were performed to validate the chosen design.