FEL2019 - List of Authors (Sydlo, C.)

Paper	Title	Page
WEB04	Few-Femtosecond Facility-Wide Synchronization of the European XFEL	318
	S. Schulz, M.K. Czwalinna, M. Felber, M. Fenner, C. Gerth, T. Kozak, T. Lamb, B. Lautenschlager, F. Ludwig, U. Mavrič, J. Müller, S. Pfeiffer, H. Schlarb, Ch. Schmidt, C. Sydlo, M. Titberidze, F. Zummack DESY, Hamburg, Germany
	The first facility-wide evaluation of the optical synchronization system at the European XFEL resulted in excellent arrival time stability of the electron bunches at the end of the 2 km long linac, being measured with two individual adjacent femtosecond-resolution bunch arrival time monitors. While each of the monitors is independently linked by a stabilized optical fiber to a master laser oscillator, with one being installed in the injector area and one in the experimental hall, these two reference lasers are tightly synchronized through another few-km long fiber link. Thus, not only the accelerator performance is being benchmarked, but equally the optical synchronization infrastructure itself. Stability on this level can only be achieved by locking the RF for cavity field control to the optical reference and requires an unprecedented synchronization of the master laser oscillator to the main RF oscillator, enabled by a novel RF/optical phase detector. Finally, with the seeders of the experiment’s optical lasers synchronized to the master laser oscillator, first experiments at two independent scientific instruments proved an X-ray/optical timing jitter of few tens of femtoseconds.
	Slides WEB04 [22.142 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEB04
About •	paper received ※ 20 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP007	Usage of the MicroTCA.4 Electronics Platform for Femtosecond Synchronization Systems	332
	M. Felber, E.P. Felber, M. Fenner, T. Kozak, T. Lamb, J. Müller, K.P. Przygoda, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack DESY, Hamburg, Germany
	At the European XFEL and FLASH at DESY optical synchronization systems are installed providing sub-10 femtosecond electron bunch arrival time stability and laser oscillator synchronization to carry out time-resolved pump-probe experiments with high precision. The synchronization system supplies critical RF stations with short- and long-term phase-stable reference signals for precise RF field detection and control while bunch arrival times are processed in beam-based feedbacks to further time-stabilize the FEL pulses. Experimental lasers are tightly locked to the optical reference using balanced optical cross-correlation. In this paper, we describe the electronic hardware for supervision and real-time control of the optical synchronization system. It comprises various MicroTCA.4 modules including fast digitizers, FPGA processor boards, and drivers for piezos and stepper-motors. Advantages of the system are the high-level of integration, state-of-the-art performance, flexibility, and remote maintainability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP007
About •	paper received ※ 20 August 2019 paper accepted ※ 26 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP010	Femtosecond Laser-to-RF Synchronization and RF Reference Distribution at the European XFEL	343
	T. Lamb, M. Felber, T. Kozak, J. Müller, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack DESY, Hamburg, Germany
	At the European XFEL, optical pulses from a mode-locked laser are distributed in an optical fiber network providing femtosecond stability throughout the accelerator facility. Due to the large number of RF reference clients and because of the expected higher reliability, the 1.3 GHz RF reference signals are distributed by a conventional coaxial RF distribution system. However, the provided ultra-low phase noise 1.3 GHz RF reference signals may drift over time. To remove these drifts, an optical reference module (REFM-OPT) has been developed to detect and correct environmentally induced phase errors of the RF reference. It uses a femtosecond long-term stable laser-to-RF phase detector, based on an integrated Mach-Zehnder amplitude modulator (MZM), to measure and resynchronize the RF phase with respect to the laser pulses from the optical synchronization system with high accuracy. Currently nine REFM-OPTs are permanently operated at the European XFEL, delivering femtosecond stable RF reference signals for critical accelerating field control stations. The operation experience will be reported together with a detailed evaluation of the REFM-OPT performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP010
About •	paper received ※ 20 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP016	Precise Laser-to-RF Synchronization of Photocathode Lasers	364
	M. Titberidze, M. Felber, T. Kozak, T. Lamb, J. Müller, H. Schlarb, S. Schulz, C. Sydlo, F. Zummack DESY, Hamburg, Germany
	RF photo-injectors are used in various large, mid and small-scale accelerator facilities such as X-ray Free Electron Lasers (XFELs), external injection-based laser-driven plasma accelerators (LPAs) and ultrafast electron diffraction (UED) sources. Many of these facilities require a high precision synchronization of the photo-injector laser system, either because of beam dynamics reasons or the photo-injector directly impacting pump-probe experiments carried out to study physical processes on femtosecond timescales. It is thus crucial to achieve synchronization in the order of 10 fs rms or below between the photocathode laser and the RF source driving the RF gun. In this paper, we present the laser-to-RF synchronization setup employed to lock a commercial near-infrared (NIR) photocathode laser oscillator to a 2.998 GHz RF source. Together with the first results achieving ~ 10 fs rms timing jitter in the measurement bandwidth from 10 Hz up to 1 MHz, we describe an advanced synchronization setup as a future upgrade, promising even lower timing jitter and most importantly long-term timing drift stability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP016
About •	paper received ※ 20 August 2019 paper accepted ※ 27 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Few-Femtosecond Facility-Wide Synchronization of the European XFEL

318

S. Schulz, M.K. Czwalinna, M. Felber, M. Fenner, C. Gerth, T. Kozak, T. Lamb, B. Lautenschlager, F. Ludwig, U. Mavrič, J. Müller, S. Pfeiffer, H. Schlarb, Ch. Schmidt, C. Sydlo, M. Titberidze, F. Zummack
DESY, Hamburg, Germany

The first facility-wide evaluation of the optical synchronization system at the European XFEL resulted in excellent arrival time stability of the electron bunches at the end of the 2 km long linac, being measured with two individual adjacent femtosecond-resolution bunch arrival time monitors. While each of the monitors is independently linked by a stabilized optical fiber to a master laser oscillator, with one being installed in the injector area and one in the experimental hall, these two reference lasers are tightly synchronized through another few-km long fiber link. Thus, not only the accelerator performance is being benchmarked, but equally the optical synchronization infrastructure itself. Stability on this level can only be achieved by locking the RF for cavity field control to the optical reference and requires an unprecedented synchronization of the master laser oscillator to the main RF oscillator, enabled by a novel RF/optical phase detector. Finally, with the seeders of the experiment’s optical lasers synchronized to the master laser oscillator, first experiments at two independent scientific instruments proved an X-ray/optical timing jitter of few tens of femtoseconds.

Slides WEB04 [22.142 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEB04

About •

paper received ※ 20 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019

Export •

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

WEP007

Usage of the MicroTCA.4 Electronics Platform for Femtosecond Synchronization Systems

332

M. Felber, E.P. Felber, M. Fenner, T. Kozak, T. Lamb, J. Müller, K.P. Przygoda, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack
DESY, Hamburg, Germany

At the European XFEL and FLASH at DESY optical synchronization systems are installed providing sub-10 femtosecond electron bunch arrival time stability and laser oscillator synchronization to carry out time-resolved pump-probe experiments with high precision. The synchronization system supplies critical RF stations with short- and long-term phase-stable reference signals for precise RF field detection and control while bunch arrival times are processed in beam-based feedbacks to further time-stabilize the FEL pulses. Experimental lasers are tightly locked to the optical reference using balanced optical cross-correlation. In this paper, we describe the electronic hardware for supervision and real-time control of the optical synchronization system. It comprises various MicroTCA.4 modules including fast digitizers, FPGA processor boards, and drivers for piezos and stepper-motors. Advantages of the system are the high-level of integration, state-of-the-art performance, flexibility, and remote maintainability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP007

About •

paper received ※ 20 August 2019 paper accepted ※ 26 August 2019 issue date ※ 05 November 2019

Export •

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

WEP010

Femtosecond Laser-to-RF Synchronization and RF Reference Distribution at the European XFEL

343

T. Lamb, M. Felber, T. Kozak, J. Müller, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack
DESY, Hamburg, Germany

At the European XFEL, optical pulses from a mode-locked laser are distributed in an optical fiber network providing femtosecond stability throughout the accelerator facility. Due to the large number of RF reference clients and because of the expected higher reliability, the 1.3 GHz RF reference signals are distributed by a conventional coaxial RF distribution system. However, the provided ultra-low phase noise 1.3 GHz RF reference signals may drift over time. To remove these drifts, an optical reference module (REFM-OPT) has been developed to detect and correct environmentally induced phase errors of the RF reference. It uses a femtosecond long-term stable laser-to-RF phase detector, based on an integrated Mach-Zehnder amplitude modulator (MZM), to measure and resynchronize the RF phase with respect to the laser pulses from the optical synchronization system with high accuracy. Currently nine REFM-OPTs are permanently operated at the European XFEL, delivering femtosecond stable RF reference signals for critical accelerating field control stations. The operation experience will be reported together with a detailed evaluation of the REFM-OPT performance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP010

About •

paper received ※ 20 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019

Export •

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

WEP016

Precise Laser-to-RF Synchronization of Photocathode Lasers

364

M. Titberidze, M. Felber, T. Kozak, T. Lamb, J. Müller, H. Schlarb, S. Schulz, C. Sydlo, F. Zummack
DESY, Hamburg, Germany

RF photo-injectors are used in various large, mid and small-scale accelerator facilities such as X-ray Free Electron Lasers (XFELs), external injection-based laser-driven plasma accelerators (LPAs) and ultrafast electron diffraction (UED) sources. Many of these facilities require a high precision synchronization of the photo-injector laser system, either because of beam dynamics reasons or the photo-injector directly impacting pump-probe experiments carried out to study physical processes on femtosecond timescales. It is thus crucial to achieve synchronization in the order of 10 fs rms or below between the photocathode laser and the RF source driving the RF gun. In this paper, we present the laser-to-RF synchronization setup employed to lock a commercial near-infrared (NIR) photocathode laser oscillator to a 2.998 GHz RF source. Together with the first results achieving ~ 10 fs rms timing jitter in the measurement bandwidth from 10 Hz up to 1 MHz, we describe an advanced synchronization setup as a future upgrade, promising even lower timing jitter and most importantly long-term timing drift stability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP016

About •

paper received ※ 20 August 2019 paper accepted ※ 27 August 2019 issue date ※ 05 November 2019

Export •

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