IPAC2017 - List of Authors (Schlarb, H.)

Paper	Title	Page
MOPAB044	X-Band TDS Project	184
	B. Marchetti, R.W. Aßmann, B. Beutner, J. Branlard, F. Christie, R.T.P. D'Arcy, W. Decking, U. Dorda, J. Herrmann, M. Hoffmann, M. Hüning, O. Krebs, G. Kube, S. Lederer, F. Ludwig, F. Marutzky, D. Marx, J. Osterhoff, I. Peperkorn, S. Pfeiffer, F. Poblotzki, J. Rönsch-Schulenburg, J. Rothenburg, H. Schlarb, M. Scholz, S. Schreiber, M. Vogt, A. Wagner, T. Wilksen, K. Wittenburg DESY, Hamburg, Germany M. Bopp, H.-H. Braun, P. Craievich, M. Pedrozzi, E. Prat, S. Reiche, K. Rolli, R. Zennaro PSI, Villigen PSI, Switzerland N. Catalán Lasheras, A. Grudiev, G. McMonagle, W. Wuensch CERN, Geneva, Switzerland
	Based on the success of the X-Band Transverse Deflecting Structure (TDS) diagnostic at LCLS, a collaboration between DESY, PSI and CERN has formed with the aim of developing and building an advanced modular X-Band TDS system. The designed TDS has the new feature of providing variable polarization of the deflecting field. The possibility of changing the orientation of the streaking field of the TDS to an arbitrary azimuthal angle allows for 3D characterization of the phase space using tomographic methods. Moreover the complete 6D characterization of the beam phase space is possible by combining this technique with quadrupole scans and a dipole spectrometer. As this new cavity design requires very high manufacturing precision to guarantee highest azimuthal symmetry of the structure to avoid the deterioration of the polarization of the streaking field, the high precision tuning-free assembly procedures developed at PSI for the SwissFEL C-band accelerating structures will be used for the manufacturing*. The high-power rf system is based on the CERN-based X-band test stands. We summarize in this work the status of the projects and its main technical parameters. C. Behrens et al. , Nat. Comm. 4762 (2014). A. Grudiev, CLIC-note-1067 (2016). * D. Marx et al., contribution to this conference proceedings. **** U. Ellenberger et al., FEL 2013, TUPS017.
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MOPIK072	Recent Upgrades of the Bunch Arrival Time Monitors at FLASH and European XFEL	695
	M. Viti, M.K. Czwalinna, H. Dinter, C. Gerth, K.P. Przygoda, R. Rybaniec, H. Schlarb DESY, Hamburg, Germany
	In modern free electron laser facilities like FLASH and European XFEL a high resolution intra train bunch arrival time measurement is mandatory, providing a crucial information for the beam based feedback system. At FLASH and European XFEL a reliable arrival time detection with a resolution better than 0.1% is required for a broad range of bunch charges, from 1 nC down to 20 pC. The system developed is based on electro-optical sampling where an ultra-short pulsed laser is employed. Several bunch arrival time monitors (BAM) were developed and are since 2012 in operation at the FLASH facility. A major upgrade involved the development of new hardware and software based on the MTCA standard. Special operation mode at both facilities includes the possibility to subdivide the bunch train in up to three segments, each with different bunch energy and charge, causing variation of the time jitter within the bunch train itself. A further upgrade includes the measurement of the arrival time and application of delay correction for each of the three segments. In this poster, we describe the development, installation and commissioning of the hardware, firmware and software of the new system.
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TUPAB040	Status Update of the SINBAD-ARES Linac Under Construction at DESY	1412
	B. Marchetti, R.W. Aßmann, S. Baark, U. Dorda, C. Engling, K. Flöttmann, I. Hartl, J. Hauser, J. Herrmann, M. Hüning, M. Körfer, B. Krause, G. Kube, J. Kuhlmann, S. Lederer, F. Ludwig, D. Marx, F. Mayet, M. Pelzer, I. Peperkorn, A. Petrov, S. Pfeiffer, S. Pumpe, J. Rothenburg, H. Schlarb, M. Titberidze, S. Vilcins, M. Werner, Ch. Wiebers, L. Winkelmann, K. Wittenburg, J. Zhu DESY, Hamburg, Germany
	ARES (Accelerator Research Experiment at Sinbad) is a linear accelerator for the production of low charge (from few pC to sub-pC) electron bunches with 100 MeV energy, fs and sub-fs duration and excellent arrival time stability. This experiment is currently under construction at DESY Hamburg and it is foreseen to start operation by the beginning of 2018 with the commissioning of the RF-gun. After an initial beam characterization phase, ARES will provide high temporal resolution probes for testing novel acceleration techniques, such as Laser driven plasma Wake-Field Acceleration (LWFA), Dielectric Laser Acceleration (DLA) and THz driven acceleration. In this work we present an overview of the present design of the linac with a special focus on 3D integration and planned installation phases of the beamline.
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TUPIK006	FLASHForward - A Future-Oriented Wakefield-Accelerator Research and Development Facility at FLASH	1692
	R.T.P. D'Arcy, A. Aschikhin, C. Behrens, S. Bohlen, J. Dale, L. Di Lucchio, M. Felber, B. Foster, L. Goldberg, J.-N. Gruse, Z. Hu, G. Indorg, S. Karstensen, O. S. Kononenko, V. Libov, K. Ludwig, A. Martinez de la Ossa, F. Marutzky, T.J. Mehrling, P. Niknejadi, J. Osterhoff, P. Pourmoussavi, M. Quast, J.-H. Röckemann, L. Schaper, H. Schlarb, B. Schmidt, S. Schröder, J.-P. Schwinkendorf, B. Sheeran, G.E. Tauscher, J. Thesinga, V. Wacker, S. Weichert, S. Wesch, S. Wunderlich, J. Zemella DESY, Hamburg, Germany B. Foster, T.J. Mehrling University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany A. Knetsch University of Hamburg, Hamburg, Germany C.A.J. Palmer, M.J.V. Streeter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	Funding: Helmholtz ARD program and the VH-VI-503 FLASHForward is a beam-driven plasma wakefield acceleration facility, currently under construction at DESY (Hamburg, Germany), aiming at the stable generation of electron beams of several GeV with small energy spread and emittance. High-quality 1 GeV-class electron beams from the free-electron laser FLASH will act as the wake driver. The setup will allow studies of external injection as well as density-downramp injection. With a triangular-shaped driver beam electron energies of up to 5 GeV from a few centimeters of plasma can be anticipated. Particle-In-Cell simulations are used to assess the feasibility of each technique and to predict properties of the accelerated electron bunches. In this contribution the current status of FLASHForward, along with recent experimental developments and upcoming scientific plans, will be reviewed.
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THOAA3	Installation and First Commissioning of the LLRF System for the European XFEL	3638
	J. Branlard, G. Ayvazyan, V. Ayvazyan, Ł. Butkowski, M. Fenner, M.K. Grecki, M. Hierholzer, M. Hoffmann, M. Killenberg, D. Kostin, D. Kühn, F. Ludwig, D.R. Makowski, U. Mavrič, M. Omet, S. Pfeiffer, H. Pryschelski, K.P. Przygoda, A.T. Rosner, R. Rybaniec, H. Schlarb, Ch. Schmidt, N. Shehzad, B. Szczepanski, G. Varghese, H.C. Weddig, R. Wedel, M. Wiencek, B.Y. Yang DESY, Hamburg, Germany W. Cichalewski, F. Makowski, A. Mielczarek, P. Perek TUL-DMCS, Łódź, Poland K. Czuba, P.K. Jatczak, T.P. Leśniak, K. Oliwa, D. Sikora, M. Urbański, W. Wierba Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland A.S. Nawaz TUHH, Hamburg, Germany
	The installation phase of the European X-ray free laser electron laser (XFEL) is finished, leaving place for its commissioning phase. This contribution summarizes the low-level radio frequency (LLRF) installation steps, illustrated with examples of its challenges and how they were addressed. The commissioning phase is also presented, with a special emphasis on the effort placed into developing LLRF automation tools to support the commissioning of such a large scale accelerator. The first results of the LLRF commissioning of the XFEL injector and first RF stations in the main linac are also given.
	Slides THOAA3 [15.800 MB]
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THOAB2	MicroTCA Technology Lab at DESY: Start-Up Phase Summary	3659
	T. Walter, M. Fenner, K. Kull, H. Schlarb DESY, Hamburg, Germany
	Funding: The MicroTCA Technology Lab at DESY is a Helmholtz Innovation Lab (HIL-02) and jointly funded by DESY, the Helmholtz Association, and industry. Over the last decade, technology transfer has emerged as an important mission of major public research facilities. Funding agencies, regional governments and society at large have placed high hopes in the combination of scientific research and on-site technology transfer departments that can turn discoveries and research tools into marketable products. Pursuing economic interests while preserving scientific freedom is a delicate balancing act that requires novel instruments in finance, administration and governance. The Helmholtz Association of German Research Centres addressed this challenge with a set of new frameworks: the Helmholtz Validation Funds (HVF) and the Helmholtz Innovation Labs (HIL). MicroTCA is a case in point: Since 2009, DESY has upgraded this standard significantly to provide state-of-the-art LLRF systems for the facilities FLASH and European XFEL. When the technology sparked interest elsewhere, DESY bundled its transfer activities in the HVF project MicroTCA.4 for Industry (2012-2015) and the HIL project MicroTCA Technology Lab (since October 2016). We report on intermediate results achieved by the MicroTCA Technology Lab after seven months of operation.
	Slides THOAB2 [6.655 MB]
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THPAB103	On-Line RF Amplitude and Phase Calibration	3957
	M.K. Grecki, V. Ayvazyan, J. Branlard, M. Hoffmann, M. Omet, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany
	The accelerating RF field has crucial importance on the beam properties. It is not only used just to accelerate particles but also to shape the bunches at bunch compressors. It is really important to control and measure the field as seen by the beam while usually only indirect (not using the beam) field measurements are available*. Since they are affected by many contributions the measurements must be always calibrated to the beam. Usually this calibration is performed at special operating conditions that prevents normal operation of the accelerator. During normal operation the calibrations is assumed to not drift which is certainly not perfectly true and introduce some control errors. The paper shows how to extract the RF-beam calibration from RF signals during normal operating condition (when RF feed-back, beam loading compensation, learning feed-forward etc. are active). All the algorithms and computations were performed on signals recorded at FLASH accelerator but the main idea is general and can be used at other locations as well.
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THPAB105	Design and Operation of the Integrated 1.3 GHz Optical Reference Module with Femtosecond Precision	3963
	T. Lamb, Ł. Butkowski, E.P. Felber, M. Felber, M. Fenner, S. Jabłoński, T. Kozak, J.M. Müller, P. Prędki, H. Schlarb, C. Sydlo, M. Titberidze, F. Zummack DESY, Hamburg, Germany
	In modern Free-Electron Lasers like FLASH or the European XFEL, the short and long-term stability of RF reference signals gains in importance. The requirements are driven by the demand for short FEL pulses and low-jitter FEL operation. In previous publications, a novel, integrated Mach-Zehnder Interferometer based scheme for a phase detector between the optical and the electrical domain was presented and evaluated. This Laser-to-RF phase detector is the key component of the integrated 1.3 GHz Optical Reference Module (REFM-OPT) for FLASH and the European XFEL. The REFM-OPT will phase-stabilize 1.3 GHz RF reference signals to the pulsed optical synchronization systems in these accelerators. Design choices in the final hardware configuration are presented together with measurement results and a performance evaluation from the first operation period in the European XFEL.
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THPAB106	Experience with Single Cavity and Piezo Controls for Short, Long Pulse and CW Operation	3966
	K.P. Przygoda, V. Ayvazyan, R. Rybaniec, H. Schlarb, Ch. Schmidt, J.K. Sekutowicz DESY, Hamburg, Germany P. Echevarria HZB, Berlin, Germany
	We present a compact RF control system for SCRF single cavities based on MicroTCA.4 equipped with specialized advanced mezzanine cards (AMCs) and rear transition modules (RTMs). To sense the RF signals from the cavity and to drive the high power source, a DRTM-DWC8VM1 module is used equipped with 8 analog field detectors and one RF vector modulator. Fast cavity frequency tuning is achieved by piezo-actuators attached to the cavity and a RTM piezo-driver module (DRTM-PZT4). Data processing of the RF signals and the real-time control algorithms are implemented on a Virtex-6 FPGA and a Spartan FPGAs within two AMCs (SIS8300-L2V2 and DAMC-FMC20). The compact single cavity control system was tested at Cryo Module Test Bench (CMTB) at DESY. Software and firmware were developed to support all possible modes, the short pulse (SP), the long pulse (LP) and CW operation mode with duty cycles ranging from 1 % to 100%. The SP mode used a high power multi-beam klystron at low QL ~3·10⁶. For the LP mode (up to 50% duty cycle) and the CW mode a 120 kW IOT tube was used at QL up to 1.5·10⁷. Within this paper we present the achieved performance and report on the operation experience on such system.
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THPAB108	Femtosecond Optical Synchronization System for the European XFEL	3969
	C. Sydlo, M. Felber, C. Gerth, T. Kozak, T. Lamb, J.M. Müller, H. Schlarb, F. Zummack DESY, Hamburg, Germany
	Accurate timing synchronization on the femtosecond timescale is an essential installation for time-resolved experiments at free-electron lasers (FELs) such as FLASH and the upcoming European XFEL. Conventional RF timing systems suffer from RF attenuation for such long distances and have reached to date a limit for synchronization precision of around 100 femtoseconds. An optical synchronization system is used at FLASH and is based on the distribution of femtosecond laser pulses over actively stabilized optical fibers. The upcoming European XFEL has raised the demands due to its large number of stabilized optical fibers and a length of 3400 m. The increased lengths for the stabilized optical fibers necessitated major advancement in precision to achieve the requirement of less than 10 femtosecond precision. This paper reports on the status of the laser-based synchronization system at the European XFEL.
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THPAB109	Fs Level Laser-to-RF Synchronization at REGAE	3972
	M. Titberidze, M. Felber, T. Lamb, H. Schlarb, C. Sydlo DESY, Hamburg, Germany R.A. Loch MPSD, Hamburg, Germany
	The Relativistic Electron Gun for Atomic Exploration (REGAE) is a unique linear accelerator capable of producing ultrashort (~ 10 fs) electron bunches for studying fast processes in matter by means of ultrafast electron diffraction (UED) experiments. Additionally, REGAE is suitable for upcoming external injection experiments for laser wakefield acceleration (LWFA). In order to carry out both mentioned experiments, it is crucial to achieve fs level stability in terms of Laser-to-RF synchronization. In this paper we present an advanced laser-to-RF synchronization scheme based on integrated Mach-Zehnder modulator. The setup demonstrated the Titanium Sapphire photo-injector laser synchronization with 11 fs (rms) precision in the bandwidth up to 100 kHz. Long term timing drift measurements showed unprecedented peak-to-peak stability of 31 fs (7 fs rms) over 43 hours of measurement time. In addition, AM-PM coefficient of the MZM based laser-to-RF synchronization setup has been evaluated and showed a factor of 10 improved performance compared to conventional direct conversion based laser synchronization setup.
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THPAB110	Custom Optomechanics for the Optical Synchronization System at the European XFEL	3976
	F. Zummack, M. Felber, C. Gerth, T. Lamb, J.M. Müller, M. Schäfer, H. Schlarb, C. Sydlo DESY, Hamburg, Germany
	Free-electron-lasers like the upcoming European XFEL demand highly reliable optical synchronization in range of few femtoseconds. The well known optical synchronization system at FLASH had to be re-engineered to meet XFEL requirements comprising demands like ten times larger lengths and raised numbers of optically synchronized instruments. These requirements directly convert to optomechanical precision and have yielded in a specialized design accounting for economical manufacturing technologies. These efforts resulted in reduced spatial dimensions, improved optical repeatability, maintainability and even reduced production costs. To account for thermal influences the heart of the optical synchronization system is based on an optical table made out of SuperInvar. To fully exploit its excellent thermal expansion coefficient, mechanical details need to be taken into account. This work presents the design and its realization of the re-engineered optomechanical parts of the optical synchronization system, comprising mounting techniques, link stabilization units and optical delay lines for high drift suppression.
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Paper

Title

Page

X-Band TDS Project

184

B. Marchetti, R.W. Aßmann, B. Beutner, J. Branlard, F. Christie, R.T.P. D'Arcy, W. Decking, U. Dorda, J. Herrmann, M. Hoffmann, M. Hüning, O. Krebs, G. Kube, S. Lederer, F. Ludwig, F. Marutzky, D. Marx, J. Osterhoff, I. Peperkorn, S. Pfeiffer, F. Poblotzki, J. Rönsch-Schulenburg, J. Rothenburg, H. Schlarb, M. Scholz, S. Schreiber, M. Vogt, A. Wagner, T. Wilksen, K. Wittenburg
DESY, Hamburg, Germany
M. Bopp, H.-H. Braun, P. Craievich, M. Pedrozzi, E. Prat, S. Reiche, K. Rolli, R. Zennaro
PSI, Villigen PSI, Switzerland
N. Catalán Lasheras, A. Grudiev, G. McMonagle, W. Wuensch
CERN, Geneva, Switzerland

Based on the success of the X-Band Transverse Deflecting Structure (TDS) diagnostic at LCLS*, a collaboration between DESY, PSI and CERN has formed with the aim of developing and building an advanced modular X-Band TDS system. The designed TDS has the new feature of providing variable polarization of the deflecting field**. The possibility of changing the orientation of the streaking field of the TDS to an arbitrary azimuthal angle allows for 3D characterization of the phase space using tomographic methods***. Moreover the complete 6D characterization of the beam phase space is possible by combining this technique with quadrupole scans and a dipole spectrometer. As this new cavity design requires very high manufacturing precision to guarantee highest azimuthal symmetry of the structure to avoid the deterioration of the polarization of the streaking field, the high precision tuning-free assembly procedures developed at PSI for the SwissFEL C-band accelerating structures will be used for the manufacturing****. The high-power rf system is based on the CERN-based X-band test stands. We summarize in this work the status of the projects and its main technical parameters.
* C. Behrens et al. , Nat. Comm. 4762 (2014).
** A. Grudiev, CLIC-note-1067 (2016).
*** D. Marx et al., contribution to this conference proceedings.
**** U. Ellenberger et al., FEL 2013, TUPS017.

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MOPIK072

Recent Upgrades of the Bunch Arrival Time Monitors at FLASH and European XFEL

695

M. Viti, M.K. Czwalinna, H. Dinter, C. Gerth, K.P. Przygoda, R. Rybaniec, H. Schlarb
DESY, Hamburg, Germany

In modern free electron laser facilities like FLASH and European XFEL a high resolution intra train bunch arrival time measurement is mandatory, providing a crucial information for the beam based feedback system. At FLASH and European XFEL a reliable arrival time detection with a resolution better than 0.1% is required for a broad range of bunch charges, from 1 nC down to 20 pC. The system developed is based on electro-optical sampling where an ultra-short pulsed laser is employed. Several bunch arrival time monitors (BAM) were developed and are since 2012 in operation at the FLASH facility. A major upgrade involved the development of new hardware and software based on the MTCA standard. Special operation mode at both facilities includes the possibility to subdivide the bunch train in up to three segments, each with different bunch energy and charge, causing variation of the time jitter within the bunch train itself. A further upgrade includes the measurement of the arrival time and application of delay correction for each of the three segments. In this poster, we describe the development, installation and commissioning of the hardware, firmware and software of the new system.

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TUPAB040

Status Update of the SINBAD-ARES Linac Under Construction at DESY

1412

B. Marchetti, R.W. Aßmann, S. Baark, U. Dorda, C. Engling, K. Flöttmann, I. Hartl, J. Hauser, J. Herrmann, M. Hüning, M. Körfer, B. Krause, G. Kube, J. Kuhlmann, S. Lederer, F. Ludwig, D. Marx, F. Mayet, M. Pelzer, I. Peperkorn, A. Petrov, S. Pfeiffer, S. Pumpe, J. Rothenburg, H. Schlarb, M. Titberidze, S. Vilcins, M. Werner, Ch. Wiebers, L. Winkelmann, K. Wittenburg, J. Zhu
DESY, Hamburg, Germany

ARES (Accelerator Research Experiment at Sinbad) is a linear accelerator for the production of low charge (from few pC to sub-pC) electron bunches with 100 MeV energy, fs and sub-fs duration and excellent arrival time stability. This experiment is currently under construction at DESY Hamburg and it is foreseen to start operation by the beginning of 2018 with the commissioning of the RF-gun. After an initial beam characterization phase, ARES will provide high temporal resolution probes for testing novel acceleration techniques, such as Laser driven plasma Wake-Field Acceleration (LWFA), Dielectric Laser Acceleration (DLA) and THz driven acceleration. In this work we present an overview of the present design of the linac with a special focus on 3D integration and planned installation phases of the beamline.

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TUPIK006

FLASHForward - A Future-Oriented Wakefield-Accelerator Research and Development Facility at FLASH

1692

R.T.P. D'Arcy, A. Aschikhin, C. Behrens, S. Bohlen, J. Dale, L. Di Lucchio, M. Felber, B. Foster, L. Goldberg, J.-N. Gruse, Z. Hu, G. Indorg, S. Karstensen, O. S. Kononenko, V. Libov, K. Ludwig, A. Martinez de la Ossa, F. Marutzky, T.J. Mehrling, P. Niknejadi, J. Osterhoff, P. Pourmoussavi, M. Quast, J.-H. Röckemann, L. Schaper, H. Schlarb, B. Schmidt, S. Schröder, J.-P. Schwinkendorf, B. Sheeran, G.E. Tauscher, J. Thesinga, V. Wacker, S. Weichert, S. Wesch, S. Wunderlich, J. Zemella
DESY, Hamburg, Germany
B. Foster, T.J. Mehrling
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
A. Knetsch
University of Hamburg, Hamburg, Germany
C.A.J. Palmer, M.J.V. Streeter
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

Funding: Helmholtz ARD program and the VH-VI-503
FLASHForward is a beam-driven plasma wakefield acceleration facility, currently under construction at DESY (Hamburg, Germany), aiming at the stable generation of electron beams of several GeV with small energy spread and emittance. High-quality 1 GeV-class electron beams from the free-electron laser FLASH will act as the wake driver. The setup will allow studies of external injection as well as density-downramp injection. With a triangular-shaped driver beam electron energies of up to 5 GeV from a few centimeters of plasma can be anticipated. Particle-In-Cell simulations are used to assess the feasibility of each technique and to predict properties of the accelerated electron bunches. In this contribution the current status of FLASHForward, along with recent experimental developments and upcoming scientific plans, will be reviewed.

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THOAA3

Installation and First Commissioning of the LLRF System for the European XFEL

3638

J. Branlard, G. Ayvazyan, V. Ayvazyan, Ł. Butkowski, M. Fenner, M.K. Grecki, M. Hierholzer, M. Hoffmann, M. Killenberg, D. Kostin, D. Kühn, F. Ludwig, D.R. Makowski, U. Mavrič, M. Omet, S. Pfeiffer, H. Pryschelski, K.P. Przygoda, A.T. Rosner, R. Rybaniec, H. Schlarb, Ch. Schmidt, N. Shehzad, B. Szczepanski, G. Varghese, H.C. Weddig, R. Wedel, M. Wiencek, B.Y. Yang
DESY, Hamburg, Germany
W. Cichalewski, F. Makowski, A. Mielczarek, P. Perek
TUL-DMCS, Łódź, Poland
K. Czuba, P.K. Jatczak, T.P. Leśniak, K. Oliwa, D. Sikora, M. Urbański, W. Wierba
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
A.S. Nawaz
TUHH, Hamburg, Germany

The installation phase of the European X-ray free laser electron laser (XFEL) is finished, leaving place for its commissioning phase. This contribution summarizes the low-level radio frequency (LLRF) installation steps, illustrated with examples of its challenges and how they were addressed. The commissioning phase is also presented, with a special emphasis on the effort placed into developing LLRF automation tools to support the commissioning of such a large scale accelerator. The first results of the LLRF commissioning of the XFEL injector and first RF stations in the main linac are also given.

Slides THOAA3 [15.800 MB]

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THOAB2

MicroTCA Technology Lab at DESY: Start-Up Phase Summary

3659

T. Walter, M. Fenner, K. Kull, H. Schlarb
DESY, Hamburg, Germany

Funding: The MicroTCA Technology Lab at DESY is a Helmholtz Innovation Lab (HIL-02) and jointly funded by DESY, the Helmholtz Association, and industry.
Over the last decade, technology transfer has emerged as an important mission of major public research facilities. Funding agencies, regional governments and society at large have placed high hopes in the combination of scientific research and on-site technology transfer departments that can turn discoveries and research tools into marketable products. Pursuing economic interests while preserving scientific freedom is a delicate balancing act that requires novel instruments in finance, administration and governance. The Helmholtz Association of German Research Centres addressed this challenge with a set of new frameworks: the Helmholtz Validation Funds (HVF) and the Helmholtz Innovation Labs (HIL). MicroTCA is a case in point: Since 2009, DESY has upgraded this standard significantly to provide state-of-the-art LLRF systems for the facilities FLASH and European XFEL. When the technology sparked interest elsewhere, DESY bundled its transfer activities in the HVF project MicroTCA.4 for Industry (2012-2015) and the HIL project MicroTCA Technology Lab (since October 2016). We report on intermediate results achieved by the MicroTCA Technology Lab after seven months of operation.

Slides THOAB2 [6.655 MB]

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THPAB103

On-Line RF Amplitude and Phase Calibration

3957

M.K. Grecki, V. Ayvazyan, J. Branlard, M. Hoffmann, M. Omet, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany

The accelerating RF field has crucial importance on the beam properties. It is not only used just to accelerate particles but also to shape the bunches at bunch compressors. It is really important to control and measure the field as seen by the beam while usually only indirect (not using the beam) field measurements are available*. Since they are affected by many contributions the measurements must be always calibrated to the beam. Usually this calibration is performed at special operating conditions that prevents normal operation of the accelerator. During normal operation the calibrations is assumed to not drift which is certainly not perfectly true and introduce some control errors. The paper shows how to extract the RF-beam calibration from RF signals during normal operating condition (when RF feed-back, beam loading compensation, learning feed-forward etc. are active). All the algorithms and computations were performed on signals recorded at FLASH accelerator but the main idea is general and can be used at other locations as well.

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THPAB105

Design and Operation of the Integrated 1.3 GHz Optical Reference Module with Femtosecond Precision

3963

T. Lamb, Ł. Butkowski, E.P. Felber, M. Felber, M. Fenner, S. Jabłoński, T. Kozak, J.M. Müller, P. Prędki, H. Schlarb, C. Sydlo, M. Titberidze, F. Zummack
DESY, Hamburg, Germany

In modern Free-Electron Lasers like FLASH or the European XFEL, the short and long-term stability of RF reference signals gains in importance. The requirements are driven by the demand for short FEL pulses and low-jitter FEL operation. In previous publications, a novel, integrated Mach-Zehnder Interferometer based scheme for a phase detector between the optical and the electrical domain was presented and evaluated. This Laser-to-RF phase detector is the key component of the integrated 1.3 GHz Optical Reference Module (REFM-OPT) for FLASH and the European XFEL. The REFM-OPT will phase-stabilize 1.3 GHz RF reference signals to the pulsed optical synchronization systems in these accelerators. Design choices in the final hardware configuration are presented together with measurement results and a performance evaluation from the first operation period in the European XFEL.

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THPAB106

Experience with Single Cavity and Piezo Controls for Short, Long Pulse and CW Operation

3966

K.P. Przygoda, V. Ayvazyan, R. Rybaniec, H. Schlarb, Ch. Schmidt, J.K. Sekutowicz
DESY, Hamburg, Germany
P. Echevarria
HZB, Berlin, Germany

We present a compact RF control system for SCRF single cavities based on MicroTCA.4 equipped with specialized advanced mezzanine cards (AMCs) and rear transition modules (RTMs). To sense the RF signals from the cavity and to drive the high power source, a DRTM-DWC8VM1 module is used equipped with 8 analog field detectors and one RF vector modulator. Fast cavity frequency tuning is achieved by piezo-actuators attached to the cavity and a RTM piezo-driver module (DRTM-PZT4). Data processing of the RF signals and the real-time control algorithms are implemented on a Virtex-6 FPGA and a Spartan FPGAs within two AMCs (SIS8300-L2V2 and DAMC-FMC20). The compact single cavity control system was tested at Cryo Module Test Bench (CMTB) at DESY. Software and firmware were developed to support all possible modes, the short pulse (SP), the long pulse (LP) and CW operation mode with duty cycles ranging from 1 % to 100%. The SP mode used a high power multi-beam klystron at low QL ~3·10⁶. For the LP mode (up to 50% duty cycle) and the CW mode a 120 kW IOT tube was used at QL up to 1.5·10⁷. Within this paper we present the achieved performance and report on the operation experience on such system.

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THPAB108

Femtosecond Optical Synchronization System for the European XFEL

3969

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

Accurate timing synchronization on the femtosecond timescale is an essential installation for time-resolved experiments at free-electron lasers (FELs) such as FLASH and the upcoming European XFEL. Conventional RF timing systems suffer from RF attenuation for such long distances and have reached to date a limit for synchronization precision of around 100 femtoseconds. An optical synchronization system is used at FLASH and is based on the distribution of femtosecond laser pulses over actively stabilized optical fibers. The upcoming European XFEL has raised the demands due to its large number of stabilized optical fibers and a length of 3400 m. The increased lengths for the stabilized optical fibers necessitated major advancement in precision to achieve the requirement of less than 10 femtosecond precision. This paper reports on the status of the laser-based synchronization system at the European XFEL.

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THPAB109

Fs Level Laser-to-RF Synchronization at REGAE

3972

M. Titberidze, M. Felber, T. Lamb, H. Schlarb, C. Sydlo
DESY, Hamburg, Germany
R.A. Loch
MPSD, Hamburg, Germany

The Relativistic Electron Gun for Atomic Exploration (REGAE) is a unique linear accelerator capable of producing ultrashort (~ 10 fs) electron bunches for studying fast processes in matter by means of ultrafast electron diffraction (UED) experiments. Additionally, REGAE is suitable for upcoming external injection experiments for laser wakefield acceleration (LWFA). In order to carry out both mentioned experiments, it is crucial to achieve fs level stability in terms of Laser-to-RF synchronization. In this paper we present an advanced laser-to-RF synchronization scheme based on integrated Mach-Zehnder modulator. The setup demonstrated the Titanium Sapphire photo-injector laser synchronization with 11 fs (rms) precision in the bandwidth up to 100 kHz. Long term timing drift measurements showed unprecedented peak-to-peak stability of 31 fs (7 fs rms) over 43 hours of measurement time. In addition, AM-PM coefficient of the MZM based laser-to-RF synchronization setup has been evaluated and showed a factor of 10 improved performance compared to conventional direct conversion based laser synchronization setup.

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THPAB110

Custom Optomechanics for the Optical Synchronization System at the European XFEL

3976

F. Zummack, M. Felber, C. Gerth, T. Lamb, J.M. Müller, M. Schäfer, H. Schlarb, C. Sydlo
DESY, Hamburg, Germany

Free-electron-lasers like the upcoming European XFEL demand highly reliable optical synchronization in range of few femtoseconds. The well known optical synchronization system at FLASH had to be re-engineered to meet XFEL requirements comprising demands like ten times larger lengths and raised numbers of optically synchronized instruments. These requirements directly convert to optomechanical precision and have yielded in a specialized design accounting for economical manufacturing technologies. These efforts resulted in reduced spatial dimensions, improved optical repeatability, maintainability and even reduced production costs. To account for thermal influences the heart of the optical synchronization system is based on an optical table made out of SuperInvar. To fully exploit its excellent thermal expansion coefficient, mechanical details need to be taken into account. This work presents the design and its realization of the re-engineered optomechanical parts of the optical synchronization system, comprising mounting techniques, link stabilization units and optical delay lines for high drift suppression.

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