FEL2014 - List of Authors (Ischebeck, R.)

Paper

Title

Page

General Strategy for the Commissioning of the ARAMIS Undulators with a 3 GeV Electron Beam

107

M. Calvi, M. Aiba, M. Brügger, S. Danner, R. Ganter, R. Ischebeck, L. Patthey, T. Schietinger, T. Schmidt
PSI, Villigen PSI, Switzerland

The commissioning of the first SwissFEL undulator line (Aramis) is planned for the beginning of 2017. Each undulator is equipped with a 5-axis camshaft system to remotely adjust its position in the micrometer range and a gap drive system to set K-values between 0.1 and 1.8. In the following paper the beam-based alignment of the undulator with respect to the golden orbit, the definition of look-up tables for the local correction strategy (minimization of undulator field errors), the fine-tuning of the K-values as well as the setting of the phase shifters are addressed. When applicable both electron beam and light based methods are presented and compared.

MOP048

Temporal Diagnostics Measurements with the Pulse Arrival and Length Monitor (PALM) at SACLA

I. Gorgisyan, C.P. Hauri
EPFL, Lausanne, Switzerland
I. Gorgisyan, C.P. Hauri, R. Ischebeck, P.N. Juranic, B. Monoszlai, B. Monoszlai, L. Patthey, C. Pradervand, M. Radovic, A.G. Stepanov
PSI, Villigen PSI, Switzerland
R. Ivanov
DESY, Hamburg, Germany
J. Liu
XFEL. EU, Hamburg, Germany
B. Monoszlai
University of Pecs, Pécs, Hungary
K. Ogawa, T. Togashi, M. Yabashi
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
S. Owada
JASRI/RIKEN, Hyogo, Japan
M. Yabashi
RIKEN/SPring-8, Hyogo, Japan

The development of FEL facilities all over the world necessitates the development of temporal diagnostics for the photon pulses these facilities provide. Photon pulse length and arrival time measurements are particularly helpful for both the operators and the users of an FEL for monitoring the operation of the facility and the experiments. The development of FEL facilities all over the world necessitates the development of temporal diagnostics for the photon pulses these facilities provide. Swiss Free Electron Laser is the upcoming X-ray FEL facility at PSI, that will provide short pulsed radiation in hard X-ray region. In order to face the challenge of measuring the temporal properties of such pulses, a pulse arrival time and length monitor (PALM) is currently being developed at PSI. The concept of THz-streak camera is used to measure the arrival time relative to a beamline laser and the length of a photon pulse. A prototype version of the device was used for measurements at SACLA in order to show the feasibility of the device for photon pulses in hard X-ray region and test the reliability of the measurements. The first results from the beamtime at SACLA will be presented. The plans for further development of the system will be discussed.

Poster MOP048 [8.009 MB]

THA01

THz Streak Camera for FELTemporal Diagnostics: Concepts and Considerations

640

P.N. Juranic, R. Abela, I. Gorgisyan, C.P. Hauri, R. Ischebeck, B. Monoszlai, L. Patthey, C. Pradervand, M. Radovic, L. Rivkin, V. Schlott, A.G. Stepanov
PSI, Villigen PSI, Switzerland
I. Gorgisyan, C.P. Hauri, L. Rivkin
EPFL, Lausanne, Switzerland
R. Ivanov, P. Peier
DESY, Hamburg, Germany
J. Liu
XFEL. EU, Hamburg, Germany
B. Monoszlai
University of Pecs, Pécs, Hungary
K. Ogawa, T. Togashi, M. Yabashi
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
S. Owada
JASRI/RIKEN, Hyogo, Japan

The accurate, non-destructive measurements of FEL pulse length and arrival time relative to an experimental laser are necessary for operators and users alike. The FEL operators can get a better understanding of their machine and the optics of an FEL by examining the pulse length changes of the photons coming to the user stations, and the users can use the arrival time and pulse length information to better understand their data. PSI has created the pulse arrival and length monitor (PALM) based on the THz-streak camera concept for measurement at x-ray FELs, meant to be used at the upcoming SwissFEL facility. The first results from the experimental beamtime at SACLA will be presented, showcasing the accuracy and reliability of the device. Further plans for improvement and eventual integration into SwissFEL will also be presented.

Slides THA01 [5.798 MB]

THB02

Experimental Results of Diagnostics Response for Longitudinal Phase Space

657

F. Frei, V.R. Arsov, H. Brands, R. Ischebeck, B. Kalantari, R. Kalt, B. Keil, W. Koprek, F. Löhl, G.L. Orlandi, Á. Saá Hernández, T. Schilcher, V. Schlott
PSI, Villigen PSI, Switzerland

At SwissFEL, electron bunches will be accelerated, shaped, and longitudinally compressed by different radio frequency (RF) structures (S-, C-, and X-band) in combination with magnetic chicanes. In order to meet the envisaged performance, it is planned to regulate the different RF parameters based on the signals from numerous electron beam diagnostics. Here we will present experimental results of the diagnostics response on RF phase and field amplitude variations that were obtained at the SwissFEL Injector Test Facility.

Slides THB02 [6.110 MB]

THP059

The Laser Heater System of SwissFEL

871

M. Pedrozzi, M. Calvi, R. Ischebeck, S. Reiche, C. Vicario
PSI, Villigen PSI, Switzerland
B.D. Fell, N. Thompson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Short wavelength FELs are generally driven by high-brilliance photo-cathode RF-guns which generate electron beams with an uncorrelated energy spread on the order of 1 keV or less. These extremely cold beams can easily develop micro-bunching instabilities caused by longitudinal space charge forces after the compression process. This can result in a blow up of the energy spread and emittance beyond the tolerable level for SASE emission. It has been demonstrated theoretically and experimentally [1] that a controlled increase of the uncorrelated energy spread to typically a few keV is sufficient to strongly reduce the instability growth. In the laser heater system, one achieves a controlled increase of the beam energy spread by a resonant interaction of the electron beam with a transversally polarized laser beam inside of an undulator magnet. The momentum modulation resulting from the energy exchange within the undulator is consequently smeared out in the transmission line downstream of the laser heater system. In SwissFEL, the laser heater system is located after the first two S-band accelerating structures at a beam energy of 150 MeV. This paper describes the layout and the sub-components of this system.
[1] Z. Huang, et al, Phys. Rev. Special Topics – Accelerator and beams 13, 020703 (2010)

THP081

Beam Loss Monitors for the SwissFEL

C. Ozkan, M. Calvi, R. Ischebeck, D. Llorente Sancho, F. Löhl, G.L. Orlandi, P. Pollet, V. Schlott, T. Schmidt
PSI, Villigen PSI, Switzerland

There are currently three types of monitors planned for tracking and minimizing beam losses at the SwissFEL. Fiber-based loss monitors will provide information on the longitudinal loss location, help reduce losses at undulators and measure losses due to insertion of wire scanners for transverse beam profile measurements. They shall be integrated to the Machine Protection System due to their fast response capabilities. The dose deposited over time at the undulators shall be measured with RadFETs and readout using the DOSFET L-02 reader. Characterization of all three types of loss monitors have been carried out at the SwissFEL Injector Test Facility. This contribution shall provide in-depth description of the monitors along with their complete readout chain and results from the characterization studies.

THP088

Comparison of Quadrupole Scan and Multi-screen Method for the Measurement of Projected and Slice Emittance at the SwissFEL Injector Test Facility

941

M. Yan, B. Beutner, C. Gerth
DESY, Hamburg, Germany
R. Ischebeck, E. Prat
PSI, Villigen PSI, Switzerland

High-brightness electron bunches with small transverse emittance are required to drive X-ray free-electron lasers (FELs). For the measurement of the transverse emittance, the quadrupole scan and multi-screen methods are the two most common procedures. By employing a transverse deflecting structure, the measurement of the slice emittance becomes feasible. The quadrupole scan is more flexible in freely choosing the data points during the scan, while the multi-screen method allows on-line emittance measurements utilising off-axis screens in combination with fast kicker magnets. The latter is especially the case for high-repetition multi-bunch FELs, such as the European XFEL, which offer the possibility of on-line diagnostics. In this paper, we present comparative measurements of projected and slice emittance applying these two methods at the SwissFEL Injector Test Facility and discuss the implementation of on-line diagnostics at the European XFEL.

THP091

Design and Test of Wire-Scanners for SwissFEL

948

G.L. Orlandi, M. Baldinger, H. Brands, P. Heimgartner, R. Ischebeck, A. Kammerer, F. Löhl, R. Lüscher, P. Mohanmurthy, C. Ozkan, B. Rippstein, V. Schlott, L. Schulz, C. Seiler, S. Trovati, P. Valitutti, D. Zimoch
PSI, Villigen PSI, Switzerland

The SwissFEL light-facility will provide coherent X-rays in the wavelength region 7-0.7 nm and 0.7-0.1 nm. In SwissFEL, view-screens and wire-scanners will be used to monitor the transverse profile of a 200/10pC electron beam with a normalized emittance of 0.4/0.2 mm.mrad and a final energy of 5.7 GeV. Compared to view screens, wire-scanners offer a quasi-non-destructive monitoring of the beam transverse profile without suffering from possible micro-bunching of the electron beam. The main aspects of the design, laboratory characterization and beam-test of the SwissFEL wire-scanner prototype will be presented.

THP097

Longitudinal Response Matrix Simulations for the SwissFEL Injector Test Facility

964

Á. Saá Hernández, F. Frei, R. Ischebeck
PSI, Villigen PSI, Switzerland
B. Beutner
DESY, Hamburg, Germany

The Singular Value Decomposition (SVD) method has been applied to the SwissFEL Injector Test Facility to identify and better expose the various relationships among the possible jitter sources affecting the longitudinal phase space distribution and the longitudinal diagnostic elements that measure them. To this end, several longitudinal tracking simulations have been run using the Litrack code. In these simulations the RF and laser jitter sources are varied one-by-one within a range spanning twice their expected stability. The particle distributions have been dumped at the diagnostic locations and the measured quantities analyzed. A matrix has been built by linearly fitting the response of each measured quantity to each jitter source. This response matrix is normalized to the jitter source stability and the instrumentation accuracy, and it is inverted and analyzed using SVD. From the eigenvalues and eigenvectors the sensitivity of the diagnostics to the jitters can be evaluated and their specifications and locations optimized.

THP098

CameraLink High-Speed Camera for Bunch Profiling

968

D. Llorente Sancho, H. Brands, R. Ischebeck, P. Pollet, V. Schlott
PSI, Villigen PSI, Switzerland

In the context of upcoming SwissFEL linear accelerator, we are working on a high-speed high-resolution instrument capable of delivering good sensitivity even in dark conditions. The camera selected is a PCO. Edge with SCMOS technology and an ultra-low noise sensor with 2560x2160 pixel resolution working at 100Hz. This allows for single bunch monitoring in SwissFEL, allowing eventually for on-the-fly inter-bunch image processing. The communication between the PCO. Edge camera and a last-generation Kintex7 FPGA has been demonstrated using a prototyping evaluation board and an 850-nm optical link connected to a 10Gbit SFP+ transceiver. Rudimentary packet processing has been implemented to confirm the satisfactory operation of the new link-layer protocol X-CameraLinkHS, specifically development for high-speed image transmission. We aim for online image processing and investigating the feasibility of achieving inter-bunch feedback (< 10 ms).

Paper	Title	Page
MOP040	General Strategy for the Commissioning of the ARAMIS Undulators with a 3 GeV Electron Beam	107
	M. Calvi, M. Aiba, M. Brügger, S. Danner, R. Ganter, R. Ischebeck, L. Patthey, T. Schietinger, T. Schmidt PSI, Villigen PSI, Switzerland
	The commissioning of the first SwissFEL undulator line (Aramis) is planned for the beginning of 2017. Each undulator is equipped with a 5-axis camshaft system to remotely adjust its position in the micrometer range and a gap drive system to set K-values between 0.1 and 1.8. In the following paper the beam-based alignment of the undulator with respect to the golden orbit, the definition of look-up tables for the local correction strategy (minimization of undulator field errors), the fine-tuning of the K-values as well as the setting of the phase shifters are addressed. When applicable both electron beam and light based methods are presented and compared.

MOP048	Temporal Diagnostics Measurements with the Pulse Arrival and Length Monitor (PALM) at SACLA
	I. Gorgisyan, C.P. Hauri EPFL, Lausanne, Switzerland I. Gorgisyan, C.P. Hauri, R. Ischebeck, P.N. Juranic, B. Monoszlai, B. Monoszlai, L. Patthey, C. Pradervand, M. Radovic, A.G. Stepanov PSI, Villigen PSI, Switzerland R. Ivanov DESY, Hamburg, Germany J. Liu XFEL. EU, Hamburg, Germany B. Monoszlai University of Pecs, Pécs, Hungary K. Ogawa, T. Togashi, M. Yabashi RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan S. Owada JASRI/RIKEN, Hyogo, Japan M. Yabashi RIKEN/SPring-8, Hyogo, Japan
	The development of FEL facilities all over the world necessitates the development of temporal diagnostics for the photon pulses these facilities provide. Photon pulse length and arrival time measurements are particularly helpful for both the operators and the users of an FEL for monitoring the operation of the facility and the experiments. The development of FEL facilities all over the world necessitates the development of temporal diagnostics for the photon pulses these facilities provide. Swiss Free Electron Laser is the upcoming X-ray FEL facility at PSI, that will provide short pulsed radiation in hard X-ray region. In order to face the challenge of measuring the temporal properties of such pulses, a pulse arrival time and length monitor (PALM) is currently being developed at PSI. The concept of THz-streak camera is used to measure the arrival time relative to a beamline laser and the length of a photon pulse. A prototype version of the device was used for measurements at SACLA in order to show the feasibility of the device for photon pulses in hard X-ray region and test the reliability of the measurements. The first results from the beamtime at SACLA will be presented. The plans for further development of the system will be discussed.
	Poster MOP048 [8.009 MB]

THA01	THz Streak Camera for FELTemporal Diagnostics: Concepts and Considerations	640
	P.N. Juranic, R. Abela, I. Gorgisyan, C.P. Hauri, R. Ischebeck, B. Monoszlai, L. Patthey, C. Pradervand, M. Radovic, L. Rivkin, V. Schlott, A.G. Stepanov PSI, Villigen PSI, Switzerland I. Gorgisyan, C.P. Hauri, L. Rivkin EPFL, Lausanne, Switzerland R. Ivanov, P. Peier DESY, Hamburg, Germany J. Liu XFEL. EU, Hamburg, Germany B. Monoszlai University of Pecs, Pécs, Hungary K. Ogawa, T. Togashi, M. Yabashi RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan S. Owada JASRI/RIKEN, Hyogo, Japan
	The accurate, non-destructive measurements of FEL pulse length and arrival time relative to an experimental laser are necessary for operators and users alike. The FEL operators can get a better understanding of their machine and the optics of an FEL by examining the pulse length changes of the photons coming to the user stations, and the users can use the arrival time and pulse length information to better understand their data. PSI has created the pulse arrival and length monitor (PALM) based on the THz-streak camera concept for measurement at x-ray FELs, meant to be used at the upcoming SwissFEL facility. The first results from the experimental beamtime at SACLA will be presented, showcasing the accuracy and reliability of the device. Further plans for improvement and eventual integration into SwissFEL will also be presented.
	Slides THA01 [5.798 MB]

THB02	Experimental Results of Diagnostics Response for Longitudinal Phase Space	657
	F. Frei, V.R. Arsov, H. Brands, R. Ischebeck, B. Kalantari, R. Kalt, B. Keil, W. Koprek, F. Löhl, G.L. Orlandi, Á. Saá Hernández, T. Schilcher, V. Schlott PSI, Villigen PSI, Switzerland
	At SwissFEL, electron bunches will be accelerated, shaped, and longitudinally compressed by different radio frequency (RF) structures (S-, C-, and X-band) in combination with magnetic chicanes. In order to meet the envisaged performance, it is planned to regulate the different RF parameters based on the signals from numerous electron beam diagnostics. Here we will present experimental results of the diagnostics response on RF phase and field amplitude variations that were obtained at the SwissFEL Injector Test Facility.
	Slides THB02 [6.110 MB]

THP059	The Laser Heater System of SwissFEL	871
	M. Pedrozzi, M. Calvi, R. Ischebeck, S. Reiche, C. Vicario PSI, Villigen PSI, Switzerland B.D. Fell, N. Thompson STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Short wavelength FELs are generally driven by high-brilliance photo-cathode RF-guns which generate electron beams with an uncorrelated energy spread on the order of 1 keV or less. These extremely cold beams can easily develop micro-bunching instabilities caused by longitudinal space charge forces after the compression process. This can result in a blow up of the energy spread and emittance beyond the tolerable level for SASE emission. It has been demonstrated theoretically and experimentally [1] that a controlled increase of the uncorrelated energy spread to typically a few keV is sufficient to strongly reduce the instability growth. In the laser heater system, one achieves a controlled increase of the beam energy spread by a resonant interaction of the electron beam with a transversally polarized laser beam inside of an undulator magnet. The momentum modulation resulting from the energy exchange within the undulator is consequently smeared out in the transmission line downstream of the laser heater system. In SwissFEL, the laser heater system is located after the first two S-band accelerating structures at a beam energy of 150 MeV. This paper describes the layout and the sub-components of this system. [1] Z. Huang, et al, Phys. Rev. Special Topics – Accelerator and beams 13, 020703 (2010)

THP081	Beam Loss Monitors for the SwissFEL
	C. Ozkan, M. Calvi, R. Ischebeck, D. Llorente Sancho, F. Löhl, G.L. Orlandi, P. Pollet, V. Schlott, T. Schmidt PSI, Villigen PSI, Switzerland
	There are currently three types of monitors planned for tracking and minimizing beam losses at the SwissFEL. Fiber-based loss monitors will provide information on the longitudinal loss location, help reduce losses at undulators and measure losses due to insertion of wire scanners for transverse beam profile measurements. They shall be integrated to the Machine Protection System due to their fast response capabilities. The dose deposited over time at the undulators shall be measured with RadFETs and readout using the DOSFET L-02 reader. Characterization of all three types of loss monitors have been carried out at the SwissFEL Injector Test Facility. This contribution shall provide in-depth description of the monitors along with their complete readout chain and results from the characterization studies.

THP088	Comparison of Quadrupole Scan and Multi-screen Method for the Measurement of Projected and Slice Emittance at the SwissFEL Injector Test Facility	941
	M. Yan, B. Beutner, C. Gerth DESY, Hamburg, Germany R. Ischebeck, E. Prat PSI, Villigen PSI, Switzerland
	High-brightness electron bunches with small transverse emittance are required to drive X-ray free-electron lasers (FELs). For the measurement of the transverse emittance, the quadrupole scan and multi-screen methods are the two most common procedures. By employing a transverse deflecting structure, the measurement of the slice emittance becomes feasible. The quadrupole scan is more flexible in freely choosing the data points during the scan, while the multi-screen method allows on-line emittance measurements utilising off-axis screens in combination with fast kicker magnets. The latter is especially the case for high-repetition multi-bunch FELs, such as the European XFEL, which offer the possibility of on-line diagnostics. In this paper, we present comparative measurements of projected and slice emittance applying these two methods at the SwissFEL Injector Test Facility and discuss the implementation of on-line diagnostics at the European XFEL.

THP091	Design and Test of Wire-Scanners for SwissFEL	948
	G.L. Orlandi, M. Baldinger, H. Brands, P. Heimgartner, R. Ischebeck, A. Kammerer, F. Löhl, R. Lüscher, P. Mohanmurthy, C. Ozkan, B. Rippstein, V. Schlott, L. Schulz, C. Seiler, S. Trovati, P. Valitutti, D. Zimoch PSI, Villigen PSI, Switzerland
	The SwissFEL light-facility will provide coherent X-rays in the wavelength region 7-0.7 nm and 0.7-0.1 nm. In SwissFEL, view-screens and wire-scanners will be used to monitor the transverse profile of a 200/10pC electron beam with a normalized emittance of 0.4/0.2 mm.mrad and a final energy of 5.7 GeV. Compared to view screens, wire-scanners offer a quasi-non-destructive monitoring of the beam transverse profile without suffering from possible micro-bunching of the electron beam. The main aspects of the design, laboratory characterization and beam-test of the SwissFEL wire-scanner prototype will be presented.

THP097	Longitudinal Response Matrix Simulations for the SwissFEL Injector Test Facility	964
	Á. Saá Hernández, F. Frei, R. Ischebeck PSI, Villigen PSI, Switzerland B. Beutner DESY, Hamburg, Germany
	The Singular Value Decomposition (SVD) method has been applied to the SwissFEL Injector Test Facility to identify and better expose the various relationships among the possible jitter sources affecting the longitudinal phase space distribution and the longitudinal diagnostic elements that measure them. To this end, several longitudinal tracking simulations have been run using the Litrack code. In these simulations the RF and laser jitter sources are varied one-by-one within a range spanning twice their expected stability. The particle distributions have been dumped at the diagnostic locations and the measured quantities analyzed. A matrix has been built by linearly fitting the response of each measured quantity to each jitter source. This response matrix is normalized to the jitter source stability and the instrumentation accuracy, and it is inverted and analyzed using SVD. From the eigenvalues and eigenvectors the sensitivity of the diagnostics to the jitters can be evaluated and their specifications and locations optimized.

THP098	CameraLink High-Speed Camera for Bunch Profiling	968
	D. Llorente Sancho, H. Brands, R. Ischebeck, P. Pollet, V. Schlott PSI, Villigen PSI, Switzerland
	In the context of upcoming SwissFEL linear accelerator, we are working on a high-speed high-resolution instrument capable of delivering good sensitivity even in dark conditions. The camera selected is a PCO. Edge with SCMOS technology and an ultra-low noise sensor with 2560x2160 pixel resolution working at 100Hz. This allows for single bunch monitoring in SwissFEL, allowing eventually for on-the-fly inter-bunch image processing. The communication between the PCO. Edge camera and a last-generation Kintex7 FPGA has been demonstrated using a prototyping evaluation board and an 850-nm optical link connected to a 10Gbit SFP+ transceiver. Rudimentary packet processing has been implemented to confirm the satisfactory operation of the new link-layer protocol X-CameraLinkHS, specifically development for high-speed image transmission. We aim for online image processing and investigating the feasibility of achieving inter-bunch feedback (< 10 ms).