IBIC2019 - List of Keywords (FEL)

Paper	Title	Other Keywords	Page
MOPP019	Development and Evaluation of an Alternative Sensor Lifetime Enhancement Technique Used with the Online-Radiation-Monitoring System (DosiMon) at the European XFEL at DESY, Hamburg	radiation, operation, electron, controls	122
	F. Schmidt-Föhre, S. Arab, D. Nölle, R. Susen DESY, Hamburg, Germany
	The European XFEL (E-XFEL), that started operation in September 2017 at the DESY/XFEL site in Hamburg/Germany uses a single-tunnel concept, forcing all frontend machine devices and electronics to be located inside the accelerator tunnel. Electro-magnetic showers, mainly produced by gun dark-current, RF cavity field-emission and beam-losses expose these devices to damaging irradiation. The new Online-Radiation-Monitoring-System (DosiMon) is mainly used for surveillance of radiation sensitive permanent magnet structures, diagnostic devices and rack-housed electronics. The integrated dose from Gamma- and optional future Neutron-radiation measurements can be monitored online by the DosiMon system. Safety limits ensure the correct function of monitored devices, provided by lifecycle estimations as measures for on time part exchange, to prevent significant radiation damage. A first expansion state currently enables more than 500 gamma measuring points. The development of a new sensor lifetime enhancement technique for the utilized RadFet sensors is presented together with corresponding evaluation measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP019
About •	paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPP020	First Tests Using Sipm Based Beam Loss Monitors at the European XFEL	undulator, detector, photon, radiation	127
	T. Wamsat, P.A. Smirnov DESY, Hamburg, Germany
	The European XFEL MTCA based Beam Loss Monitor System (BLM) is composed of about 450 monitors using photomultiplier tubes (PMTs). BLMs installed in the SASE undulator intersections show high signals at electron energy higher 16 GeV or photon energy higher 14 keV due to background synchrotron radiation which directly affects the PMT. The amplitude of this signal can get that high that, also without using any scintillating material, the BLMs get blind for real losses. Also different lead arrangements did not shield the signal sufficiently. First tests show that a Silicon photomultiplier (SiPM) is not affected. Also there are several advantages to use SiPM, they are cheaper by factor of 40 and operating voltage is below 45V. First test will be presented and how it can get implemented in the existing BLMs and BLM system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP020
About •	paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPP035	Electron Beam Diagnostics Concept for the LWFA Driven FEL at ELI-Beamlines	electron, diagnostics, cavity, plasma	184
	K.O. Kruchinin, D. Kocon, A.Y. Molodozhentsev ELI-BEAMS, Prague, Czech Republic A. Lyapin JAI, Egham, Surrey, United Kingdom
	Uniquely short high energy electron bunches produced by compact Laser Wakefield Accelerators (LWFA) are attractive for the development of new generation Free Electron Lasers (FEL). Although the beam quality of LWFA is still significantly lower than provided by conventional accelerators, with persistent progress seen in the area of laser plasma acceleration, they have a great potential to be considered the new generation drivers for FELs and even colliders. A new LWFA based FEL project called "LUIS" is currently being commissioned at ELI-beamlines in Czech Republic. LUIS aims to demonstrate a stable generation of X-ray photons with a wavelengths of 6 nm and lower, suitable for user applications. Electron beam diagnostics are absolutely crucial for achieving LUIS’s aims. Low charge, poor beam stability and other beam properties inherent for a LWFA require rethinking and adaptation of the conventional diagnostic tools and, in some cases, development of new ones. In this paper we provide an overview of the electron beam instrumentation in LUIS with a focus on the current challenges and some discussion of the foreseen future developments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP035
About •	paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUBO02	FERMI-PSI Collaboration on Nano-Fabricated Wire-Scanners With Sub-Micrometer Resolution: Developments and Measurements.	electron, experiment, operation, emittance	249
	G.L. Orlandi, S. Borrelli, Ch. David, E. Ferrari, V. Guzenko, B. Hermann, O. Huerzeler, R. Ischebeck, C. Lombosi, C. Ozkan Loch, E. Prat PSI, Villigen PSI, Switzerland N. Cefarin, S. Dal Zilio, M. Lazzarino IOM-CNR, Trieste, Italy M. Ferianis, G. Penco, M. Veronese Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Wire-scanners with micrometer resolution are in operation at SwissFEL and FERMI for measurements of the beam emittance and for beam profile monitoring (,). In addition, both laboratories are developing and testing innovative nano-fabricated wire-scanners capable of providing sub-micrometer resolution and being quasi non-destructive to the beam. Nano-fabricated wire-scanners with a free-standing design () and a sub-micrometer resolution (*) has been already successfully tested. In the present work, innovative nano-fabricated wire-scanners joining both features of a free-standing design and sub-micrometer resolution are presented. Experimental tests carried out at SwissFEL demonstrated the capability of such innovative wire-scanner solutions to resolve transverse profiles of the electron beams with a size of 400-500 nm without incurring in any resolution limit constraint and with a minimal beam perturbation. An overview on current status and results along with future developments of these nano-fabricated wire-scanners are here presented. ()G.L.Orlandi et al. PRAB 19, 092802 (2016). ()M.Veronese et al.this Conference. ()M.Veronese et al.NIM-A 891, 32-36, (2018) (***)S.Borrelli et al. Comm. Phys.-Nature, 1, 52 (2018).
	Slides TUBO02 [10.551 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUBO02
About •	paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP001	KALYPSO: Linear Array Detector with Continuous Read-Out at MHz Frame Rates	detector, electron, radiation, laser	271
	C. Gerth, B. Steffen DESY, Hamburg, Germany M. Caselle, L. Rota KIT, Karlsruhe, Germany D.R. Makowski, A. Mielczarek TUL-DMCS, Łódź, Poland
	The novel linear array detector KALYPSO has been developed for beam diagnostics based on 1-dimensional profile measurements at high-repetition rate free-electron lasers (FEL) and synchrotron radiation facilities. The current version of KALYPSO has 256 pixels with a maximum frame rate of 2.7~MHz. The detector board, which comprises the radiation sensor, analog signal amplification, and analog-to-digital signal conversion, has been designed as a mezzanine card that can be plugged onto application-specific carrier boards for data pre-processing and transmission. Either a Si or InGaAs sensor can be mounted for the detection of visible or near infrared radiation. Results obtained in several beam diagnostics applications at the European XFEL and FLASH are presented to demonstrate the powerful capabilities of the KALYPSO detector. * The KAYLYPSO detector is a collaboration between the Karlsruhe Institute of Technology, Paul Scherrer Institut, Łódź University of Technology, and Deutsches-Elektronen Synchrotron.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP001
About •	paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP002	Direct-Sampling Coarse Bunch Arrival Time Monitor in the Free Electron Laser FLASH Based on the Fast Digitizer Implemented in the FMC VITA 57.1 Standard	electron, pick-up, timing, free-electron-laser	275
	J. Zink, M.K. Czwalinna, M. Fenner, S. Jabłoński, J. Marjanovic, H. Schlarb DESY, Hamburg, Germany F. Gerfers Technische Universität Berlin, Berlin, Germany
	At the free-electron lasers FLASH and European-XFEL bunch arrival times are monitored with a high-accuracy electro-optical based data acquisition system (BAM). Due to only a couple of picoseconds time measurement range of this system, large timing changes might cause the monitor to fail. To remove any ambiguity and for health status monitoring a high-speed direct-sampling FPGA mezzanine card (FMC) and an analogue RF front-end was added. The circuitry has lower precision than the electro-optical based BAM, but it can determine bunch arrival time with respect to a reference signal over a large time range, i.e. of the order of 1 ms. After restarts or larger energy changes during operation, the electron bunch arrival time may have been changed by tens or even hundreds of picoseconds, which causes that the BAM is out of its operation range and needs to be recalibrated. With the solution developed, the BAM gets the coarse bunch timing from the digitizer and adjusts its optical delay lines accordingly. This allows for finding the operation point fast and automatically. Performance data of the fast direct-sampling digitizer FMC and first measurement data from FLASH will be presented.
	Poster TUPP002 [3.810 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP002
About •	paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP010	A Fast Wire Scanner System for the European XFEL	timing, operation, detector, optics	304
	T. Lensch, B. Beutner, T. Wamsat DESY, Hamburg, Germany
	The European-XFEL is an X-ray Free Electron Laser facility located in Hamburg (Germany). The 17.5 GeV superconducting accelerator will provide photons simultaneously to several user stations. Currently 14 Wire Scanner stations are used to image transverse beam profiles in the high energy sections. These scanners provide a slow scan mode for beam halo studies and beam optics matching. When operating with long bunch trains (>100 bunches) fast scans will be used to measure beam sizes in an almost non-destructive manner. This paper briefly describes the wire scanner setup and focusses on the fast scan concept and first measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP010
About •	paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP011	Observation of Scintillators Charging Effects at the European XFEL	electron, diagnostics, free-electron-laser, operation	308
	A.I. Novokshonov, B. Beutner, G. Kube DESY, Hamburg, Germany S.A. Strokov TPU, Tomsk, Russia
	Scintillating screens are widely used for beam profile diagnostics at various kinds of particle accelerators. At modern linac based electron machines with ultrashort bunches as the European XFEL in Hamburg (Germany), scintillators help to overcome the limitation of standard OTR based monitors imposed by the emission of coherent radiation. The XFEL injector section is equipped with four off-axis screens allowing to perform online beam profile diagnostics, i.e. a single bunch out of a bunch train is kicked onto the screen and the profile is analyzed. However, during user operation a decrease of the SASE level was observed in cases that one of the of-axis screens was used. The observation is explained by charging of the scintillator screen: each deflected bunch hitting the screens causes ionization and charging of the screen. The scintillator as good insulator keeps the charge for some time such that the non-deflected part of the bunch-train feels their Coulomb force and experiences a kick, resulting in a drop of the SASE level. This report summarizes the observations at the European XFEL and introduces a simple model for quantification of this effect.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP011
About •	paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP014	New Combined Function Wire Scanner-Screen Station for the High Resolution Transverse Profile Measurements at FERMI	electron, vacuum, operation, laser	322
	M. Veronese, A. Abrami, M. Bossi, M. Ferianis, S. Grulja, G. Penco, M. Tudor Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	We present the upgrade of the transverse profile diagnostics at the end of the FERMI Linac with a new high resolution instrumentation with the aim of improving the accuracy of the measurement of the twiss parameters and of the emittance. A scintillating screen, has been adopted instead of OTR screen due to known COTR issues. We used the same COTR suppression geometry that we had already implemented on our intra undulator screens and YAG:Ce as scintillating material. Screen based transverse profile diagnostics provide single shot measurements with a typical resolution of the order of tens of microns mainly due to refraction effects, geometry and other physical material properties. To extend the resolution to the micron level needed in case of low charge operation, we have equipped the same vacuum chamber with a wire scanner housing 10 micron tungsten wires. This paper describes the design and the first operational experience with the new device and discusses advantages as well as limitations.
	Poster TUPP014 [0.638 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP014
About •	paper received ※ 04 September 2019 paper accepted ※ 09 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP041	Observations of Long-Range and Short-Range Wakefield Effects on Electron-Beam Dynamics in TESLA-type Superconducting RF Cavities	cavity, HOM, wakefield, detector	428
	A.H. Lumpkin, N. Eddy, D.R. Edstrom, J. Ruan, R.M. Thurman-Keup Fermilab, Batavia, Illinois, USA
	Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. The Fermilab Accelerator Science and Technology (FAST) facility has a unique configuration of a photocathode rf gun beam injecting two TESLA-type single cavities (CC1 and CC2) in series prior to the cryomodule. Beam propagation off axis in these cavities can result in both long-range and short-range transverse wakefields which can lead to emittance dilution within the macropulses and micropulses, respectively. Two configurations of a Hamamatsu C5680 streak camera viewing a downstream OTR screen were utilized to track centroid shifts during the macropulse (framing mode) for the long-range case and during the micropulse for the short-range case (~10-micron spatial resolution and 2-ps temporal resolution). Steering off axis before CC1, resulted in a 100-kHz bunch centroid oscillation within the macropulse that was detected by the downstream rf BPMs and the streak camera. At 500 pC/b, 50b, and 4-mrad off-axis vertical steering into CC2, we observed an ~ 100-micron head-tail centroid shift in the streak camera image y(t) profiles which we attributed to a short-range wakefield effect. Additional results for kick-angle compensations and model results will be presented. A.H. Lumpkin et al., Phys. Rev. Accel. and Beams 21,064401 (2018).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP041
About •	paper received ※ 10 September 2019 paper accepted ※ 11 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEAO01	Technological Review of Beam Position Button Design and Manufacture	resonance, electron, simulation, electronics	448
	A.F.D. Morgan DLS, Oxfordshire, United Kingdom
	A workshop in May 2019, hosted by DLS (UK), reviewed both the design and the manufacturing aspects of beam position monitor (BPM) pick-up buttons with an integrated UHV feedthrough and coaxial connector. The UHV feedthrough technology (e.g. ceramic brazing vs glass-sealing), the limits on mechanical tolerances, reproducibility and material choices for high reliability were examined by more than 20 diagnostics users of these devices and a number of reputed manufacturers. Calibration techniques and tools and methods for inspection & testing were also assessed. This talk will present the outcome & conclusions of this workshop and identify challenges and opportunities for future BPM manufacture.
	Slides WEAO01 [1.824 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEAO01
About •	paper received ※ 05 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEAO02	Pile-Up Effect of Cold Button BPMs in the European XFEL Accelerator	resonance, cavity, electron, electronics	453
	D. Lipka, B. Lorbeer DESY, Hamburg, Germany
	The European XFEL facility is in operation with a maximum of 2700 bunches in one train. The highest bunch repetition rate is 4.5 MHz; this corresponds to a minimum time separation of 222 ns. The measurement of the beam properties for each bunch in a train is required. Therefore the beam position monitor (BPM) system needs to separate the signals from each bunch. All BPM types (button, re-entrant and cavity) fulfill this requirement except a few button BPMs installed inside of the cold accelerator module, where Pile-Up from the train can be observed. To identify the cause of this effect we measured the S-parameters during a shutdown of the accelerator, compared it with a similar BPM at the FLASH accelerator but located in a warm section and finally measured the spectrum of the button signal during beam operation. As a result, resonances were found at about 2.46 GHz with relatively high quality factor that remains within the frequency range accepted by the electronics.
	Slides WEAO02 [5.621 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEAO02
About •	paper received ※ 04 September 2019 paper accepted ※ 09 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP019	Concept of a Novel High-Bandwidth Arrival Time Monitor for Very Low Charges as a Part of the All-Optical Synchronization System at ELBE	pick-up, laser, electron, FEM	560
	A. Penirschke THM, Friedberg, Germany W. Ackermann TEMF, TU Darmstadt, Darmstadt, Germany M.K. Czwalinna, H. Schlarb DESY, Hamburg, Germany M. Kuntzsch HZDR, Dresden, Germany
	Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 05K19RO1. Numerous advanced applications of X-ray free-electron lasers require pulse durations and time resolutions in the order of only a few femtoseconds or better. The generation of these pulses to be used in time-resolved experiments require synchronization techniques that can simultaneously lock all necessary components to a precision in the range of a few fs only. The CW operated electron accelerator ELBE at the Helmholtzzentrum Dresden Rossendorf uses a all-optical synchronization system to ensure a timing stability on the few 10 fs scale. ELBE requires a minimum beam pipe diameter of 43mm that limits the achievable output voltage of the pickup structure to drive the attached electro-optical modulator. This contribution presents a concept for a novel high-bandwidth arrival time monitor with sufficient output signal for the attached EOMs for very low charges as a part of the all-optical synchronization system at ELBE.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP019
About •	paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP026	Electron Bunch Compression Monitors for Short Bunches - Commissioning Results from SwissFEL	electron, linac, radiation, detector	578
	F. Frei, R. Ischebeck PSI, Villigen PSI, Switzerland
	In SwissFEL, by using three magnetic chicanes, 3ps long electron bunches can by compressed by a factor of more than 100 down to a few fs in order to generate ultra short X-ray pulses. In order to meet the envisaged beam performance, noninvasive longitudinal diagnostic after each compression stage is essential. These bunch compression monitors measure relative bunch length changes on a shot-to-shot basis by detecting coherent edge, synchrotron or diffraction radiation emitted by the electron bunches. While after the first two magnetic chicanes, a wide spectral part is integrated on a single broadband detector, an infrared spectrometer installed after the third magnetic chicane is providing more detailed information. Here, we will mainly report on commissioning results of the third bunch compression monitor for electron bunches of a few fs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP026
About •	paper received ※ 03 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Development and Evaluation of an Alternative Sensor Lifetime Enhancement Technique Used with the Online-Radiation-Monitoring System (DosiMon) at the European XFEL at DESY, Hamburg

radiation, operation, electron, controls

122

F. Schmidt-Föhre, S. Arab, D. Nölle, R. Susen
DESY, Hamburg, Germany

The European XFEL (E-XFEL), that started operation in September 2017 at the DESY/XFEL site in Hamburg/Germany uses a single-tunnel concept, forcing all frontend machine devices and electronics to be located inside the accelerator tunnel. Electro-magnetic showers, mainly produced by gun dark-current, RF cavity field-emission and beam-losses expose these devices to damaging irradiation. The new Online-Radiation-Monitoring-System (DosiMon) is mainly used for surveillance of radiation sensitive permanent magnet structures, diagnostic devices and rack-housed electronics. The integrated dose from Gamma- and optional future Neutron-radiation measurements can be monitored online by the DosiMon system. Safety limits ensure the correct function of monitored devices, provided by lifecycle estimations as measures for on time part exchange, to prevent significant radiation damage. A first expansion state currently enables more than 500 gamma measuring points. The development of a new sensor lifetime enhancement technique for the utilized RadFet sensors is presented together with corresponding evaluation measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP019

About •

paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019

Export •

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

MOPP020

First Tests Using Sipm Based Beam Loss Monitors at the European XFEL

undulator, detector, photon, radiation

127

T. Wamsat, P.A. Smirnov
DESY, Hamburg, Germany

The European XFEL MTCA based Beam Loss Monitor System (BLM) is composed of about 450 monitors using photomultiplier tubes (PMTs). BLMs installed in the SASE undulator intersections show high signals at electron energy higher 16 GeV or photon energy higher 14 keV due to background synchrotron radiation which directly affects the PMT. The amplitude of this signal can get that high that, also without using any scintillating material, the BLMs get blind for real losses. Also different lead arrangements did not shield the signal sufficiently. First tests show that a Silicon photomultiplier (SiPM) is not affected. Also there are several advantages to use SiPM, they are cheaper by factor of 40 and operating voltage is below 45V. First test will be presented and how it can get implemented in the existing BLMs and BLM system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP020

About •

paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019

Export •

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

MOPP035

Electron Beam Diagnostics Concept for the LWFA Driven FEL at ELI-Beamlines

electron, diagnostics, cavity, plasma

184

K.O. Kruchinin, D. Kocon, A.Y. Molodozhentsev
ELI-BEAMS, Prague, Czech Republic
A. Lyapin
JAI, Egham, Surrey, United Kingdom

Uniquely short high energy electron bunches produced by compact Laser Wakefield Accelerators (LWFA) are attractive for the development of new generation Free Electron Lasers (FEL). Although the beam quality of LWFA is still significantly lower than provided by conventional accelerators, with persistent progress seen in the area of laser plasma acceleration, they have a great potential to be considered the new generation drivers for FELs and even colliders. A new LWFA based FEL project called "LUIS" is currently being commissioned at ELI-beamlines in Czech Republic. LUIS aims to demonstrate a stable generation of X-ray photons with a wavelengths of 6 nm and lower, suitable for user applications. Electron beam diagnostics are absolutely crucial for achieving LUIS’s aims. Low charge, poor beam stability and other beam properties inherent for a LWFA require rethinking and adaptation of the conventional diagnostic tools and, in some cases, development of new ones. In this paper we provide an overview of the electron beam instrumentation in LUIS with a focus on the current challenges and some discussion of the foreseen future developments.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP035

About •

paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019

Export •

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

TUBO02

FERMI-PSI Collaboration on Nano-Fabricated Wire-Scanners With Sub-Micrometer Resolution: Developments and Measurements.

electron, experiment, operation, emittance

249

G.L. Orlandi, S. Borrelli, Ch. David, E. Ferrari, V. Guzenko, B. Hermann, O. Huerzeler, R. Ischebeck, C. Lombosi, C. Ozkan Loch, E. Prat
PSI, Villigen PSI, Switzerland
N. Cefarin, S. Dal Zilio, M. Lazzarino
IOM-CNR, Trieste, Italy
M. Ferianis, G. Penco, M. Veronese
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Wire-scanners with micrometer resolution are in operation at SwissFEL and FERMI for measurements of the beam emittance and for beam profile monitoring (*,**). In addition, both laboratories are developing and testing innovative nano-fabricated wire-scanners capable of providing sub-micrometer resolution and being quasi non-destructive to the beam. Nano-fabricated wire-scanners with a free-standing design (***) and a sub-micrometer resolution (****) has been already successfully tested. In the present work, innovative nano-fabricated wire-scanners joining both features of a free-standing design and sub-micrometer resolution are presented. Experimental tests carried out at SwissFEL demonstrated the capability of such innovative wire-scanner solutions to resolve transverse profiles of the electron beams with a size of 400-500 nm without incurring in any resolution limit constraint and with a minimal beam perturbation. An overview on current status and results along with future developments of these nano-fabricated wire-scanners are here presented.
(*)G.L.Orlandi et al. PRAB 19, 092802 (2016).
(**)M.Veronese et al.this Conference.
(***)M.Veronese et al.NIM-A 891, 32-36, (2018)
(****)S.Borrelli et al. Comm. Phys.-Nature, 1, 52 (2018).

Slides TUBO02 [10.551 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUBO02

About •

paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP001

KALYPSO: Linear Array Detector with Continuous Read-Out at MHz Frame Rates

detector, electron, radiation, laser

271

C. Gerth, B. Steffen
DESY, Hamburg, Germany
M. Caselle, L. Rota
KIT, Karlsruhe, Germany
D.R. Makowski, A. Mielczarek
TUL-DMCS, Łódź, Poland

The novel linear array detector KALYPSO has been developed for beam diagnostics based on 1-dimensional profile measurements at high-repetition rate free-electron lasers (FEL) and synchrotron radiation facilities. The current version of KALYPSO has 256 pixels with a maximum frame rate of 2.7~MHz. The detector board, which comprises the radiation sensor, analog signal amplification, and analog-to-digital signal conversion, has been designed as a mezzanine card that can be plugged onto application-specific carrier boards for data pre-processing and transmission. Either a Si or InGaAs sensor can be mounted for the detection of visible or near infrared radiation. Results obtained in several beam diagnostics applications at the European XFEL and FLASH are presented to demonstrate the powerful capabilities of the KALYPSO detector.
* The KAYLYPSO detector is a collaboration between the Karlsruhe Institute of Technology, Paul Scherrer Institut, Łódź University of Technology, and Deutsches-Elektronen Synchrotron.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP001

About •

paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP002

Direct-Sampling Coarse Bunch Arrival Time Monitor in the Free Electron Laser FLASH Based on the Fast Digitizer Implemented in the FMC VITA 57.1 Standard

electron, pick-up, timing, free-electron-laser

275

J. Zink, M.K. Czwalinna, M. Fenner, S. Jabłoński, J. Marjanovic, H. Schlarb
DESY, Hamburg, Germany
F. Gerfers
Technische Universität Berlin, Berlin, Germany

At the free-electron lasers FLASH and European-XFEL bunch arrival times are monitored with a high-accuracy electro-optical based data acquisition system (BAM). Due to only a couple of picoseconds time measurement range of this system, large timing changes might cause the monitor to fail. To remove any ambiguity and for health status monitoring a high-speed direct-sampling FPGA mezzanine card (FMC) and an analogue RF front-end was added. The circuitry has lower precision than the electro-optical based BAM, but it can determine bunch arrival time with respect to a reference signal over a large time range, i.e. of the order of 1 ms. After restarts or larger energy changes during operation, the electron bunch arrival time may have been changed by tens or even hundreds of picoseconds, which causes that the BAM is out of its operation range and needs to be recalibrated. With the solution developed, the BAM gets the coarse bunch timing from the digitizer and adjusts its optical delay lines accordingly. This allows for finding the operation point fast and automatically. Performance data of the fast direct-sampling digitizer FMC and first measurement data from FLASH will be presented.

Poster TUPP002 [3.810 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP002

About •

paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP010

A Fast Wire Scanner System for the European XFEL

timing, operation, detector, optics

304

T. Lensch, B. Beutner, T. Wamsat
DESY, Hamburg, Germany

The European-XFEL is an X-ray Free Electron Laser facility located in Hamburg (Germany). The 17.5 GeV superconducting accelerator will provide photons simultaneously to several user stations. Currently 14 Wire Scanner stations are used to image transverse beam profiles in the high energy sections. These scanners provide a slow scan mode for beam halo studies and beam optics matching. When operating with long bunch trains (>100 bunches) fast scans will be used to measure beam sizes in an almost non-destructive manner. This paper briefly describes the wire scanner setup and focusses on the fast scan concept and first measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP010

About •

paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP011

Observation of Scintillators Charging Effects at the European XFEL

electron, diagnostics, free-electron-laser, operation

308

A.I. Novokshonov, B. Beutner, G. Kube
DESY, Hamburg, Germany
S.A. Strokov
TPU, Tomsk, Russia

Scintillating screens are widely used for beam profile diagnostics at various kinds of particle accelerators. At modern linac based electron machines with ultrashort bunches as the European XFEL in Hamburg (Germany), scintillators help to overcome the limitation of standard OTR based monitors imposed by the emission of coherent radiation. The XFEL injector section is equipped with four off-axis screens allowing to perform online beam profile diagnostics, i.e. a single bunch out of a bunch train is kicked onto the screen and the profile is analyzed. However, during user operation a decrease of the SASE level was observed in cases that one of the of-axis screens was used. The observation is explained by charging of the scintillator screen: each deflected bunch hitting the screens causes ionization and charging of the screen. The scintillator as good insulator keeps the charge for some time such that the non-deflected part of the bunch-train feels their Coulomb force and experiences a kick, resulting in a drop of the SASE level. This report summarizes the observations at the European XFEL and introduces a simple model for quantification of this effect.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP011

About •

paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP014

New Combined Function Wire Scanner-Screen Station for the High Resolution Transverse Profile Measurements at FERMI

electron, vacuum, operation, laser

322

M. Veronese, A. Abrami, M. Bossi, M. Ferianis, S. Grulja, G. Penco, M. Tudor
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

We present the upgrade of the transverse profile diagnostics at the end of the FERMI Linac with a new high resolution instrumentation with the aim of improving the accuracy of the measurement of the twiss parameters and of the emittance. A scintillating screen, has been adopted instead of OTR screen due to known COTR issues. We used the same COTR suppression geometry that we had already implemented on our intra undulator screens and YAG:Ce as scintillating material. Screen based transverse profile diagnostics provide single shot measurements with a typical resolution of the order of tens of microns mainly due to refraction effects, geometry and other physical material properties. To extend the resolution to the micron level needed in case of low charge operation, we have equipped the same vacuum chamber with a wire scanner housing 10 micron tungsten wires. This paper describes the design and the first operational experience with the new device and discusses advantages as well as limitations.

Poster TUPP014 [0.638 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP014

About •

paper received ※ 04 September 2019 paper accepted ※ 09 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP041

Observations of Long-Range and Short-Range Wakefield Effects on Electron-Beam Dynamics in TESLA-type Superconducting RF Cavities

cavity, HOM, wakefield, detector

428

A.H. Lumpkin, N. Eddy, D.R. Edstrom, J. Ruan, R.M. Thurman-Keup
Fermilab, Batavia, Illinois, USA

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
The Fermilab Accelerator Science and Technology (FAST) facility has a unique configuration of a photocathode rf gun beam injecting two TESLA-type single cavities (CC1 and CC2) in series prior to the cryomodule. Beam propagation off axis in these cavities can result in both long-range and short-range transverse wakefields which can lead to emittance dilution within the macropulses and micropulses, respectively. Two configurations of a Hamamatsu C5680 streak camera viewing a downstream OTR screen were utilized to track centroid shifts during the macropulse (framing mode) for the long-range case and during the micropulse for the short-range case (~10-micron spatial resolution and 2-ps temporal resolution). Steering off axis before CC1, resulted in a 100-kHz bunch centroid oscillation within the macropulse that was detected by the downstream rf BPMs and the streak camera*. At 500 pC/b, 50b, and 4-mrad off-axis vertical steering into CC2, we observed an ~ 100-micron head-tail centroid shift in the streak camera image y(t) profiles which we attributed to a short-range wakefield effect. Additional results for kick-angle compensations and model results will be presented.
*A.H. Lumpkin et al., Phys. Rev. Accel. and Beams 21,064401 (2018).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP041

About •

paper received ※ 10 September 2019 paper accepted ※ 11 September 2019 issue date ※ 10 November 2019

Export •

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

WEAO01

Technological Review of Beam Position Button Design and Manufacture

resonance, electron, simulation, electronics

448

A.F.D. Morgan
DLS, Oxfordshire, United Kingdom

A workshop in May 2019, hosted by DLS (UK), reviewed both the design and the manufacturing aspects of beam position monitor (BPM) pick-up buttons with an integrated UHV feedthrough and coaxial connector. The UHV feedthrough technology (e.g. ceramic brazing vs glass-sealing), the limits on mechanical tolerances, reproducibility and material choices for high reliability were examined by more than 20 diagnostics users of these devices and a number of reputed manufacturers. Calibration techniques and tools and methods for inspection & testing were also assessed. This talk will present the outcome & conclusions of this workshop and identify challenges and opportunities for future BPM manufacture.

Slides WEAO01 [1.824 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEAO01

About •

paper received ※ 05 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

WEAO02

Pile-Up Effect of Cold Button BPMs in the European XFEL Accelerator

resonance, cavity, electron, electronics

453

D. Lipka, B. Lorbeer
DESY, Hamburg, Germany

The European XFEL facility is in operation with a maximum of 2700 bunches in one train. The highest bunch repetition rate is 4.5 MHz; this corresponds to a minimum time separation of 222 ns. The measurement of the beam properties for each bunch in a train is required. Therefore the beam position monitor (BPM) system needs to separate the signals from each bunch. All BPM types (button, re-entrant and cavity) fulfill this requirement except a few button BPMs installed inside of the cold accelerator module, where Pile-Up from the train can be observed. To identify the cause of this effect we measured the S-parameters during a shutdown of the accelerator, compared it with a similar BPM at the FLASH accelerator but located in a warm section and finally measured the spectrum of the button signal during beam operation. As a result, resonances were found at about 2.46 GHz with relatively high quality factor that remains within the frequency range accepted by the electronics.

Slides WEAO02 [5.621 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEAO02

About •

paper received ※ 04 September 2019 paper accepted ※ 09 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP019

Concept of a Novel High-Bandwidth Arrival Time Monitor for Very Low Charges as a Part of the All-Optical Synchronization System at ELBE

pick-up, laser, electron, FEM

560

A. Penirschke
THM, Friedberg, Germany
W. Ackermann
TEMF, TU Darmstadt, Darmstadt, Germany
M.K. Czwalinna, H. Schlarb
DESY, Hamburg, Germany
M. Kuntzsch
HZDR, Dresden, Germany

Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 05K19RO1.
Numerous advanced applications of X-ray free-electron lasers require pulse durations and time resolutions in the order of only a few femtoseconds or better. The generation of these pulses to be used in time-resolved experiments require synchronization techniques that can simultaneously lock all necessary components to a precision in the range of a few fs only. The CW operated electron accelerator ELBE at the Helmholtzzentrum Dresden Rossendorf uses a all-optical synchronization system to ensure a timing stability on the few 10 fs scale. ELBE requires a minimum beam pipe diameter of 43mm that limits the achievable output voltage of the pickup structure to drive the attached electro-optical modulator. This contribution presents a concept for a novel high-bandwidth arrival time monitor with sufficient output signal for the attached EOMs for very low charges as a part of the all-optical synchronization system at ELBE.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP019

About •

paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP026

Electron Bunch Compression Monitors for Short Bunches - Commissioning Results from SwissFEL

electron, linac, radiation, detector

578

F. Frei, R. Ischebeck
PSI, Villigen PSI, Switzerland

In SwissFEL, by using three magnetic chicanes, 3ps long electron bunches can by compressed by a factor of more than 100 down to a few fs in order to generate ultra short X-ray pulses. In order to meet the envisaged beam performance, noninvasive longitudinal diagnostic after each compression stage is essential. These bunch compression monitors measure relative bunch length changes on a shot-to-shot basis by detecting coherent edge, synchrotron or diffraction radiation emitted by the electron bunches. While after the first two magnetic chicanes, a wide spectral part is integrated on a single broadband detector, an infrared spectrometer installed after the third magnetic chicane is providing more detailed information. Here, we will mainly report on commissioning results of the third bunch compression monitor for electron bunches of a few fs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP026

About •

paper received ※ 03 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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