FEL2015 - List of Keywords (controls)

Paper	Title	Other Keywords	Page
MOB01	Three-Plus Decades of Tapered Undulator FEL Physics	FEL, electron, radiation, undulator	5
	W.M. Fawley Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy W.M. Fawley SLAC, Menlo Park, California, USA
	Beginning with the classic 1981 work of Kroll-Morton-Rosenbluth (), multiple generations of FEL scientists have studied and used experimentally undulator tapering to improve and optimize the radiation output of both amplifier and oscillator FELs. Tapering has undergone a renaissance of interest, in part to make possible TW instantaneous power levels from x-ray FELs. In this talk, I will give a highly personalized (and undoubtedly strongly biased) historical survey of tapering studies beginning with the ELF 35-GHz experiments at Livermore in the mid-1980's and continuing up to quite recent studies at the LCLS at both soft and hard x-ray wavelengths. () N.M. Kroll, P.L. Morton, and M.N. Rosenbluth, IEEE J. Quantum Elec., QE-17, 1436 (1981).
	Slides MOB01 [2.106 MB]
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MOP016	Status of the Fabrication of PAL-XFEL Magnet Power Supplies	power-supply, dipole, quadrupole, operation	66
	S.-H. Jeong, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea
	PAL-XFEL has been constructing including a 10 GeV linac, hard X-ray and soft X-ray branches. PAL-XFEL required for about six hundreds of magnet power supply (MPS). The eight different prototypes of MPS are developing to confirm the performance, functions, size, heat load and so on. This paper describes the test results of the prototype MPS in major specifications. All MPSs have to be installed the end of September in 2015. The installation progress of the MPS was also described.
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MOP029	PAL XFEL Pulse Modulator System Test Results Using a High Precision CCPS	klystron, power-supply, high-voltage, resonance	89
	S.H. Kim, H.-S. Kang, G.H. Kim, I.S. Ko, S.J. Kwon, H.-S. Lee, S.S. Park, Y.J. Park PAL, Pohang, Kyungbuk, Republic of Korea M.-H. Cho POSTECH, Pohang, Kyungbuk, Republic of Korea K.Y. Jang, H.S. Shin POSCO ICT, Gyeonggi-do, Republic of Korea D.S. Kim, S.Y. Lee, M. Seo Dawonsys, Siheung-City, Republic of Korea
	PAL XFEL is supposed to install 51 units of the pulse modulator power supplies for a 10-GeV linear accelerator using S-band (2856 MHz) cavities. The requirements of the modulator stability really become very tight. The stability on beam voltage is required to be less than 50 ppm. In order to obtain the high precision stability from the modulator system, we have newly produced a capacitor charging power supply (CCPS) and obtained the target stability with 10 ppm (STD) accuracy from measuring PFN (Pulse Forming Network). The CCPS generates a maximum output voltage of 50 kV at average current of 2.4 A with 4 units of the CCPS. The modulator peak output capacity is 400 kV, 500 A and 7.5 us at a pulse repetition rate of 60 pps using CCPS, a modified type-E PFN, and a pulse transformer. In this paper, the test results of the modulator system will be described.
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MOP038	Stabilization of Magnetron Frequency for a Microtron-Driven FEL	FEL, cavity, microtron, electron	107
	B.A. Gudkov, S. Bae, K.H. Jang, Y.U. Jeong, H.W. Kim, K. Lee, S.V. Miginsky, J. Mun, S. H. Park, G.I. Shim, N. Vinokurov KAERI, Daejon, Republic of Korea S.V. Miginsky, N. Vinokurov BINP SB RAS, Novosibirsk, Russia
	Under KAERI WCI program we develop a compact pulsed microtron-driven FEL. Electron bunches trains are accelerated in the microtron and transported by the beamline to the undulator. The RF cavity in the microtron is fed by a magnetron. Any accelerator driver for a FEL should provide an electron beam having very stable parameters such as electron energy, current, and especially the bunch repetition rate in a train. All mentioned parameters depend on magnetron current. It means that special attention should be paid for the shape of the current pulse, supplied to the magnetron from the modulator. We developed the modulator project with a computer control that will provide an arbitrary shape of the magnetron current. A simplified prototype was fabricated and tested. The methods of controlling of the pulse shape are considered. Simulation and experimental results are presented.
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MOP040	Implementation of MTCA.4-based Controls for the Pulsed Optical Synchronization Systems at DESY	laser, FPGA, hardware, FEL	115
	M. Felber, L. Butkowski, M.K. Czwalinna, M. Fenner, C. Gerth, M. Heuer, E. Janas, M. Killenberg, T. Lamb, U. Mavrič, J.M. Müller, P. Peier, K.P. Przygoda, S. Ruzin, H. Schlarb, C. Sydlo, M. Titberidze, F. Zummack DESY, Hamburg, Germany T. Kozak, P. Prędki TUL-DMCS, Łódź, Poland
	Funding: This work has partly been funded by the Helmholtz Validation Fund Project MTCA.4 for Industry (HVF-0016) With the current state of the synchronization system at FLASH (Free-electron Laser in Hamburg) the arrival time between electron bunches and optical laser pulses can be synchronized to a level of 30 fs rms, e.g. for pump-probe experiments. In the course of the development of an up-scaled system for the European XFEL and the migration of control hardware to the modern MTCA.4 (Micro Telecommunications Computing Architecture) platform, all involved components of the system will be replaced with new developments. The front-end devices are upgraded. FPGAs (Field Programmable Gate Arrays) are performing the data processing and feedback calculations. In order to facilitate the firmware development, a toolset (Rapid-X) was established which allows application engineers to develop, simulate, and generate their code without help from FPGA experts in a simple and efficient way. A software tool kit (MTCA4U) provides drivers and tools for direct register access e.g. via Matlab or Python and a control system adapter, which allows the server applications to be written control system independent. In this paper, an overview on the synchronization setups and their upgrades as well as an introduction to the new hardware is given. The Rapid-X and MTCA4U tool kits are presented followed by a status report on the implementation of the new developments.
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MOP043	Influence of Environment Changes on Libera Sync 3 Long-term Stability	detector, timing, monitoring, operation	126
	S. Zorzut, M. Cargnelutti I-Tech, Solkan, Slovenia S. Hunziker PSI, Villigen PSI, Switzerland
	Libera Sync 3 can be used as a reference clock transfer system in the latest fourth generation light sources where the long-term stability is in the range of a few tens of femtoseconds of drift per day. The system has been developed in collaboration with the Paul Scherrer Institute (PSI) and first units are already tested in SwissFEL machine. In this article we present the influence of temperature and humidity changes on the long-term phase stability of the system.
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MOP048	The Design of Low Noise Magnet Power Supply	power-supply, FPGA, multipole, feedback	136
	K.-H. Park, S.-H. Jeong, Y.-G. Jung, D.E. Kim, H.-G. Lee, S.B. Lee, B.G. Oh, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea W.S. Choi, I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea
	The accelerator needs a high stable magnet power supply(MPS) with low noise output. The stability requirements of the some MPSs in accelerator were in the range of the ~10 ppm. There are many noise sources which affect the stability of MPS. Thus the design of the MPS requests much attention on the noise reduction scheme from the beginning stage. The noise on the MPS divided into some sources such as the ripple voltage coming from rectifier for the DC link, switching noise at the FET or IGBT on the high voltage, noise coming digital logics around DSP and its peripheral circuits, ground matters on the analogue signal process and so on. This paper analyzed the noise sources and described the way how to build the low noise power supply.
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MOP060	RFTweak 5 - An Efficient Longitudinal Beam Dynamics Code	GUI, diagnostics, space-charge, radiation	176
	B. Beutner, H. Dinter, M. Dohlus DESY, Hamburg, Germany
	The shaping of the longitudinal phase space in bunch compression systems is essential for efficient FEL operation. RF systems and self-field interactions contribute to the overall phase space structure. The design of the various facilities relies on extensive beam dynamics simulations to define the longitudinal dynamics. However, in everyday control room applications such techniques are often not fast enough for efficient operation, e.g. for SASE tuning. Therefore efficient longitudinal beam dynamics codes are required while still maintaining reasonable accuracy. Our approach is to pre-calculate most of the required data for self-field interactions and store them on disc to reduce required online calculation time to a minimum. In this paper we present the fast longitudinal tracking code RFTweak 5, which includes wakes, space charge, and CSR interactions. With this code the full European XFEL with a 1M particles bunch is calculated on the order of minutes on a standard laptop. Neglecting CSR effects this time reduces to seconds.
	Poster MOP060 [0.799 MB]
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TUP044	Spark EL - Single Pass BPM	software, pick-up, FPGA, instrumentation	471
	M. Žnidarčič I-Tech, Solkan, Slovenia
	Monitoring and subsequent optimization of the electron linacs and beam transfers requires specific instrumentation for beam position data acquisition and processing. Spark EL is the newly developed prototype intended for position monitoring in single or multi bunch operation linacs and transfer lines. The motivation, processing principles and first results are presented.
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TUP045	MTCA.4 Phase Detector for Femtosecond-Precision Laser Synchronization	laser, detector, timing, experiment	474
	E. Janas, M. Felber, M. Heuer, U. Mavrič, H. Schlarb DESY, Hamburg, Germany K. Czuba Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
	For time-resolved experiments at FELs such as the European XFEL an accurate synchronization of the machine is essential. The required femtosecond- level synchronization we plan to achieve with an optical synchronization system, in which an inherent part is the master laser oscillator (MLO) locked to the electrical reference. At DESY we develop a custom rear transition module in MTCA.4 standard, which will allow for different techniques of phase detection between the optical and the electrical signal, as well as locking to an optical reference using a cross-correlator. In this paper we present the current status of the development, including two basic solutions for the detection to an RF. One of the methods incorporates an external drift free detector based on the so-called MZI setup. The other one employs the currently used downconverter scheme with subsequent improvements. The module can serve for locking a variety of lasers with different repetition rates.
	Poster TUP045 [4.010 MB]
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WEP023	Two Bunches with ns-Separation with LCLS	laser, timing, experiment, photon	634
	F.-J. Decker, S. Gilevich, Z. Huang, H. Loos, A. Marinelli, C.A. Stan, J.L. Turner, Z. Van Hoover, S. Vetter SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515. The Linac Coherent Light Source (LCLS) delivers typically one bunch. Two bunches are interesting for pump / probe experiments. Two electron bunches with ps separation have been already produced using a split and delay in the laser which produces them on the gun cathode. Here we present the combination of two lasers with a combiner, this allows any time separation and is it limited to RF bucket spacing so far to about 40 ns limited by the setup of our beam containment system. Different beam energies were also provided and the most challenging part was a transverse separation of a few σs for the two beams. Although this setup was very jittery a successful user experiment was accomplished.
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WEP037	Development Activites Related to RF Cables for Good Phase Stability	feedback, electron, klystron, network	654
	J. Hu, H.-S. Kang, H.-S. Lee PAL, Pohang, Kyungbuk, Republic of Korea
	XFEL systems reqiure extreme RF stabilities in amplitude and phase. RF cables as parts of the systems also require very high stabilites. RF cable measurement is performed to choose good cables. Simple measurement method and test results are presented. To enhance the phase stability of RF cables a prototype jacket surrounding a RF cable is constructed and the test result is described. Finally, a modification for phase measurement of RF cables is presented.
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WED04	Status Report of PAL-XFEL Undulator Program	undulator, FEL, electron, radiation	769
	D.E. Kim, M.-H. Cho, Y.-G. Jung, H.-S. Kang, I.S. Ko, H.-G. Lee, S.B. Lee, W.W. Lee, B.G. Oh, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea S. Karabekyan, J. Pflüger XFEL. EU, Hamburg, Germany
	PAL-XFEL is a SASE based FEL using S-band linear accelerator, photo cathode RF Gun, and hybrid undulator system for final lazing. The undulator system is based on EU-XFEL undulator design with necessary modifications. The changes include new magnetic geometry reflecting changed magnetic requirements, and EPICs based control system. The undulator system is in measurement and tuning stage targeting to finish installation within 2015. In this report, the development, tuning, measurement efforts for PAL-XFEL undulator system will be reported.
	Slides WED04 [3.317 MB]
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Paper

Title

Other Keywords

Page

MOB01

Three-Plus Decades of Tapered Undulator FEL Physics

FEL, electron, radiation, undulator

5

W.M. Fawley
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
W.M. Fawley
SLAC, Menlo Park, California, USA

Beginning with the classic 1981 work of Kroll-Morton-Rosenbluth (*), multiple generations of FEL scientists have studied and used experimentally undulator tapering to improve and optimize the radiation output of both amplifier and oscillator FELs. Tapering has undergone a renaissance of interest, in part to make possible TW instantaneous power levels from x-ray FELs. In this talk, I will give a highly personalized (and undoubtedly strongly biased) historical survey of tapering studies beginning with the ELF 35-GHz experiments at Livermore in the mid-1980's and continuing up to quite recent studies at the LCLS at both soft and hard x-ray wavelengths.
(*) N.M. Kroll, P.L. Morton, and M.N. Rosenbluth, IEEE J. Quantum Elec., QE-17, 1436 (1981).

Slides MOB01 [2.106 MB]

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MOP016

Status of the Fabrication of PAL-XFEL Magnet Power Supplies

power-supply, dipole, quadrupole, operation

66

S.-H. Jeong, Y.-G. Jung, H.-S. Kang, D.E. Kim, I.S. Ko, H.-G. Lee, S.B. Lee, B.G. Oh, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea

PAL-XFEL has been constructing including a 10 GeV linac, hard X-ray and soft X-ray branches. PAL-XFEL required for about six hundreds of magnet power supply (MPS). The eight different prototypes of MPS are developing to confirm the performance, functions, size, heat load and so on. This paper describes the test results of the prototype MPS in major specifications. All MPSs have to be installed the end of September in 2015. The installation progress of the MPS was also described.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP029

PAL XFEL Pulse Modulator System Test Results Using a High Precision CCPS

klystron, power-supply, high-voltage, resonance

89

S.H. Kim, H.-S. Kang, G.H. Kim, I.S. Ko, S.J. Kwon, H.-S. Lee, S.S. Park, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea
M.-H. Cho
POSTECH, Pohang, Kyungbuk, Republic of Korea
K.Y. Jang, H.S. Shin
POSCO ICT, Gyeonggi-do, Republic of Korea
D.S. Kim, S.Y. Lee, M. Seo
Dawonsys, Siheung-City, Republic of Korea

PAL XFEL is supposed to install 51 units of the pulse modulator power supplies for a 10-GeV linear accelerator using S-band (2856 MHz) cavities. The requirements of the modulator stability really become very tight. The stability on beam voltage is required to be less than 50 ppm. In order to obtain the high precision stability from the modulator system, we have newly produced a capacitor charging power supply (CCPS) and obtained the target stability with 10 ppm (STD) accuracy from measuring PFN (Pulse Forming Network). The CCPS generates a maximum output voltage of 50 kV at average current of 2.4 A with 4 units of the CCPS. The modulator peak output capacity is 400 kV, 500 A and 7.5 us at a pulse repetition rate of 60 pps using CCPS, a modified type-E PFN, and a pulse transformer. In this paper, the test results of the modulator system will be described.

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP038

Stabilization of Magnetron Frequency for a Microtron-Driven FEL

FEL, cavity, microtron, electron

107

B.A. Gudkov, S. Bae, K.H. Jang, Y.U. Jeong, H.W. Kim, K. Lee, S.V. Miginsky, J. Mun, S. H. Park, G.I. Shim, N. Vinokurov
KAERI, Daejon, Republic of Korea
S.V. Miginsky, N. Vinokurov
BINP SB RAS, Novosibirsk, Russia

Under KAERI WCI program we develop a compact pulsed microtron-driven FEL. Electron bunches trains are accelerated in the microtron and transported by the beamline to the undulator. The RF cavity in the microtron is fed by a magnetron. Any accelerator driver for a FEL should provide an electron beam having very stable parameters such as electron energy, current, and especially the bunch repetition rate in a train. All mentioned parameters depend on magnetron current. It means that special attention should be paid for the shape of the current pulse, supplied to the magnetron from the modulator. We developed the modulator project with a computer control that will provide an arbitrary shape of the magnetron current. A simplified prototype was fabricated and tested. The methods of controlling of the pulse shape are considered. Simulation and experimental results are presented.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP040

Implementation of MTCA.4-based Controls for the Pulsed Optical Synchronization Systems at DESY

laser, FPGA, hardware, FEL

115

M. Felber, L. Butkowski, M.K. Czwalinna, M. Fenner, C. Gerth, M. Heuer, E. Janas, M. Killenberg, T. Lamb, U. Mavrič, J.M. Müller, P. Peier, K.P. Przygoda, S. Ruzin, H. Schlarb, C. Sydlo, M. Titberidze, F. Zummack
DESY, Hamburg, Germany
T. Kozak, P. Prędki
TUL-DMCS, Łódź, Poland

Funding: This work has partly been funded by the Helmholtz Validation Fund Project MTCA.4 for Industry (HVF-0016)
With the current state of the synchronization system at FLASH (Free-electron Laser in Hamburg) the arrival time between electron bunches and optical laser pulses can be synchronized to a level of 30 fs rms, e.g. for pump-probe experiments. In the course of the development of an up-scaled system for the European XFEL and the migration of control hardware to the modern MTCA.4 (Micro Telecommunications Computing Architecture) platform, all involved components of the system will be replaced with new developments. The front-end devices are upgraded. FPGAs (Field Programmable Gate Arrays) are performing the data processing and feedback calculations. In order to facilitate the firmware development, a toolset (Rapid-X) was established which allows application engineers to develop, simulate, and generate their code without help from FPGA experts in a simple and efficient way. A software tool kit (MTCA4U) provides drivers and tools for direct register access e.g. via Matlab or Python and a control system adapter, which allows the server applications to be written control system independent. In this paper, an overview on the synchronization setups and their upgrades as well as an introduction to the new hardware is given. The Rapid-X and MTCA4U tool kits are presented followed by a status report on the implementation of the new developments.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP043

Influence of Environment Changes on Libera Sync 3 Long-term Stability

detector, timing, monitoring, operation

126

S. Zorzut, M. Cargnelutti
I-Tech, Solkan, Slovenia
S. Hunziker
PSI, Villigen PSI, Switzerland

Libera Sync 3 can be used as a reference clock transfer system in the latest fourth generation light sources where the long-term stability is in the range of a few tens of femtoseconds of drift per day. The system has been developed in collaboration with the Paul Scherrer Institute (PSI) and first units are already tested in SwissFEL machine. In this article we present the influence of temperature and humidity changes on the long-term phase stability of the system.

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP048

The Design of Low Noise Magnet Power Supply

power-supply, FPGA, multipole, feedback

136

K.-H. Park, S.-H. Jeong, Y.-G. Jung, D.E. Kim, H.-G. Lee, S.B. Lee, B.G. Oh, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea
W.S. Choi, I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea

The accelerator needs a high stable magnet power supply(MPS) with low noise output. The stability requirements of the some MPSs in accelerator were in the range of the ~10 ppm. There are many noise sources which affect the stability of MPS. Thus the design of the MPS requests much attention on the noise reduction scheme from the beginning stage. The noise on the MPS divided into some sources such as the ripple voltage coming from rectifier for the DC link, switching noise at the FET or IGBT on the high voltage, noise coming digital logics around DSP and its peripheral circuits, ground matters on the analogue signal process and so on. This paper analyzed the noise sources and described the way how to build the low noise power supply.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP060

RFTweak 5 - An Efficient Longitudinal Beam Dynamics Code

GUI, diagnostics, space-charge, radiation

176

B. Beutner, H. Dinter, M. Dohlus
DESY, Hamburg, Germany

The shaping of the longitudinal phase space in bunch compression systems is essential for efficient FEL operation. RF systems and self-field interactions contribute to the overall phase space structure. The design of the various facilities relies on extensive beam dynamics simulations to define the longitudinal dynamics. However, in everyday control room applications such techniques are often not fast enough for efficient operation, e.g. for SASE tuning. Therefore efficient longitudinal beam dynamics codes are required while still maintaining reasonable accuracy. Our approach is to pre-calculate most of the required data for self-field interactions and store them on disc to reduce required online calculation time to a minimum. In this paper we present the fast longitudinal tracking code RFTweak 5, which includes wakes, space charge, and CSR interactions. With this code the full European XFEL with a 1M particles bunch is calculated on the order of minutes on a standard laptop. Neglecting CSR effects this time reduces to seconds.

Poster MOP060 [0.799 MB]

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TUP044

Spark EL - Single Pass BPM

software, pick-up, FPGA, instrumentation

471

M. Žnidarčič
I-Tech, Solkan, Slovenia

Monitoring and subsequent optimization of the electron linacs and beam transfers requires specific instrumentation for beam position data acquisition and processing. Spark EL is the newly developed prototype intended for position monitoring in single or multi bunch operation linacs and transfer lines. The motivation, processing principles and first results are presented.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUP045

MTCA.4 Phase Detector for Femtosecond-Precision Laser Synchronization

laser, detector, timing, experiment

474

E. Janas, M. Felber, M. Heuer, U. Mavrič, H. Schlarb
DESY, Hamburg, Germany
K. Czuba
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland

For time-resolved experiments at FELs such as the European XFEL an accurate synchronization of the machine is essential. The required femtosecond- level synchronization we plan to achieve with an optical synchronization system, in which an inherent part is the master laser oscillator (MLO) locked to the electrical reference. At DESY we develop a custom rear transition module in MTCA.4 standard, which will allow for different techniques of phase detection between the optical and the electrical signal, as well as locking to an optical reference using a cross-correlator. In this paper we present the current status of the development, including two basic solutions for the detection to an RF. One of the methods incorporates an external drift free detector based on the so-called MZI setup. The other one employs the currently used downconverter scheme with subsequent improvements. The module can serve for locking a variety of lasers with different repetition rates.

Poster TUP045 [4.010 MB]

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WEP023

Two Bunches with ns-Separation with LCLS

laser, timing, experiment, photon

634

F.-J. Decker, S. Gilevich, Z. Huang, H. Loos, A. Marinelli, C.A. Stan, J.L. Turner, Z. Van Hoover, S. Vetter
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The Linac Coherent Light Source (LCLS) delivers typically one bunch. Two bunches are interesting for pump / probe experiments. Two electron bunches with ps separation have been already produced using a split and delay in the laser which produces them on the gun cathode. Here we present the combination of two lasers with a combiner, this allows any time separation and is it limited to RF bucket spacing so far to about 40 ns limited by the setup of our beam containment system. Different beam energies were also provided and the most challenging part was a transverse separation of a few σs for the two beams. Although this setup was very jittery a successful user experiment was accomplished.

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEP037

Development Activites Related to RF Cables for Good Phase Stability

feedback, electron, klystron, network

654

J. Hu, H.-S. Kang, H.-S. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

XFEL systems reqiure extreme RF stabilities in amplitude and phase. RF cables as parts of the systems also require very high stabilites. RF cable measurement is performed to choose good cables. Simple measurement method and test results are presented. To enhance the phase stability of RF cables a prototype jacket surrounding a RF cable is constructed and the test result is described. Finally, a modification for phase measurement of RF cables is presented.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WED04

Status Report of PAL-XFEL Undulator Program

undulator, FEL, electron, radiation

769

D.E. Kim, M.-H. Cho, Y.-G. Jung, H.-S. Kang, I.S. Ko, H.-G. Lee, S.B. Lee, W.W. Lee, B.G. Oh, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea
S. Karabekyan, J. Pflüger
XFEL. EU, Hamburg, Germany

PAL-XFEL is a SASE based FEL using S-band linear accelerator, photo cathode RF Gun, and hybrid undulator system for final lazing. The undulator system is based on EU-XFEL undulator design with necessary modifications. The changes include new magnetic geometry reflecting changed magnetic requirements, and EPICs based control system. The undulator system is in measurement and tuning stage targeting to finish installation within 2015. In this report, the development, tuning, measurement efforts for PAL-XFEL undulator system will be reported.

Slides WED04 [3.317 MB]

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