IPAC2014 - Classification: 07 Accelerator Technology Main Systems / T24 Timing and Synchronization

Paper	Title	Page
WEPRI115	Design and Integration of the Optical Reference Module at 1.3 GHz for FLASH and the European XFEL	2768
	E. Janas, K. Czuba, P. Kownacki, D. Sikora Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland M.K. Czwalinna, M. Felber, T. Lamb, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack DESY, Hamburg, Germany J. Szewiński NCBJ, Świerk/Otwock, Poland
	In this paper we present recent progress on the integration and implementation of the optical reference module (REFM-OPT) for the free-electron lasers FLASH and European XFEL. In order to achieve high energy stability and low arrival time jitter of the electron beam, the accelerator requires an accurate low-level RF (LLRF) field regulation and a sophisticated synchronization scheme for various devices along the facility. The REFM-OPT is a 19” module which is responsible for resynchronizing the 1.3 GHz reference signal for the LLRF distributed by coaxial cables to a phase-stable signal of the optical synchronization system. The module provides a 1.3 GHz output signal with low phase noise and high long-term stability. Several sub-components of the REFM-OPT designed specifically for this module are described in detail. The readout electronics of the high-precision Laser-to-RF phase detector are presented as well as the integration of this key component into the 19” module. Additionally, we focus on design solutions which assure phase stability and synchronization of the 1.3 GHz signal at several high power outputs of the module.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI115
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WEPRI116	Master Oscillator for the European XFEL	2771
	L.Z. Zembala, K. Czuba, B. Gąsowski, D. Sikora Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland J. Branlard, H. Schlarb, H.C. Weddig DESY, Hamburg, Germany
	The reference signal outage causes breakdown of the synchronisation in the entire accelerator, which could result in a multi-day break in the operation. Therefore, the Master Oscillator (MO) for the European XFEL has to be redundant, in order to achieve extremely high reliability. The redundancy concept, which provides no interruption in the reference signal, requires phase coherence, fast RF switching and sustaining the RF power with a high-Q filter. These features allow to keep possible signal transitions smooth. Furthermore, the MO has to generate a 1.3 GHz signal of exceptionally good phase noise performance – jitter < 35 fs RMS integrated from 10 Hz to1 MHz. One of the problems in the way are vibrations, which have to be properly isolated to avoid microphonics effects in oscillators. The proposed MO architecture and connection with the RF distribution system is described. A basic prototype is tested and results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI116
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Design and Integration of the Optical Reference Module at 1.3 GHz for FLASH and the European XFEL

2768

E. Janas, K. Czuba, P. Kownacki, D. Sikora
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
M.K. Czwalinna, M. Felber, T. Lamb, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack
DESY, Hamburg, Germany
J. Szewiński
NCBJ, Świerk/Otwock, Poland

In this paper we present recent progress on the integration and implementation of the optical reference module (REFM-OPT) for the free-electron lasers FLASH and European XFEL. In order to achieve high energy stability and low arrival time jitter of the electron beam, the accelerator requires an accurate low-level RF (LLRF) field regulation and a sophisticated synchronization scheme for various devices along the facility. The REFM-OPT is a 19” module which is responsible for resynchronizing the 1.3 GHz reference signal for the LLRF distributed by coaxial cables to a phase-stable signal of the optical synchronization system. The module provides a 1.3 GHz output signal with low phase noise and high long-term stability. Several sub-components of the REFM-OPT designed specifically for this module are described in detail. The readout electronics of the high-precision Laser-to-RF phase detector are presented as well as the integration of this key component into the 19” module. Additionally, we focus on design solutions which assure phase stability and synchronization of the 1.3 GHz signal at several high power outputs of the module.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI115

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRI116

Master Oscillator for the European XFEL

2771

L.Z. Zembala, K. Czuba, B. Gąsowski, D. Sikora
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
J. Branlard, H. Schlarb, H.C. Weddig
DESY, Hamburg, Germany

The reference signal outage causes breakdown of the synchronisation in the entire accelerator, which could result in a multi-day break in the operation. Therefore, the Master Oscillator (MO) for the European XFEL has to be redundant, in order to achieve extremely high reliability. The redundancy concept, which provides no interruption in the reference signal, requires phase coherence, fast RF switching and sustaining the RF power with a high-Q filter. These features allow to keep possible signal transitions smooth. Furthermore, the MO has to generate a 1.3 GHz signal of exceptionally good phase noise performance – jitter < 35 fs RMS integrated from 10 Hz to1 MHz. One of the problems in the way are vibrations, which have to be properly isolated to avoid microphonics effects in oscillators. The proposed MO architecture and connection with the RF distribution system is described. A basic prototype is tested and results are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI116

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)