IBIC2018 - List of Authors (Kube, G.)

Paper	Title	Page
MOOB03	Upgrade and Status of Standard Diagnostic-Systems at FLASH and FLASHForward	13
	N. Baboi, H.T. Duhme, O. Hensler, G. Kube, T. Lensch, D. Lipka, B. Lorbeer, Re. Neumann, P.A. Smirnov, T. Wamsat, M. Werner DESY, Hamburg, Germany
	Electron beam diagnostics plays a crucial role in the precise and reliable generation of ultra-short high bril-liance XUV and soft X-ray beams at the Free Electron Laser in Hamburg (FLASH). Most diagnostic systems monitor each of up to typically 600 bunches per beam, with a frequency of up to 1 MHz, a typical charge be-tween 0.1 and 1 nC and an energy of 350 to 1250 MeV. The diagnostic monitors have recently undergone a major upgrade. This process started several years ago with the development of monitors fulfilling the requirements of the European XFEL and of the FLASH2 undulator beamline and it continued with their installation and commissioning. Later they have been further improved and an upgrade was made in the old part of the linac. Also the FLASHForward plasma-wakefield acceleration experiment has been installed in the third beamline. This paper will give an overview of the upgrade of the BPM, Toroid and BLM systems, pointing out to their improved performance. Other systems underwent a partial upgrade, mainly by having their VME-based ADCs replaced with MTCA type. The overall status of the diagnostic will be reviewed.
	Slides MOOB03 [2.728 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOOB03
About •	paper received ※ 05 September 2018 paper accepted ※ 12 September 2018 issue date ※ 29 January 2019
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WEOC01	Summary of Emittance Measurements Workshop for SLS and FELs
	U. Iriso ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain F. Ewald ESRF, Grenoble, France G. Kube, K. Wittenburg DESY, Hamburg, Germany T.M. Mitsuhashi KEK, Ibaraki, Japan V. Schlott PSI, Villigen PSI, Switzerland
	Funding: This project has received funding from the EU Horizon 2020 Research and Innovation programme, under Grant Agreement No 730871. In January 2018, a Topical Workshop on Emittance Measurements for Synchrotron Light Sources and FELs was held at ALBA inside the ARIES network. This talk will summarize the state of the art of the different emittance measurements techniques for these type of accelerators, and will present the relevant topics shown during the workshop.
	Slides WEOC01 [4.723 MB]
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WEOC03	A Simple Model to Describe Smoke Ring Shaped Beam Profile Measurements With Scintillating Screens at the European XFEL	366
	G. Kube, S. Liu, A.I. Novokshonov, M. Scholz DESY, Hamburg, Germany
	Standard beam profile measurements of high-brightness electron beams based on OTR may be hampered by coherence effects. Therefore it was decided for the European XFEL to measure transverse beam profiles based on scintillating screen monitors using LYSO:Ce. While it is possible to resolve beam sizes down to a few micrometers with this scintillator, the experience during the XFEL commissioning showed that the measured emittance values were significantly larger than the expected ones. In addition, beam profiles measured at bunch charges of a few hundred pC showed a ’smoke ring’ structure. While coherent OTR emission and beam dynamical influence can be excluded, it is assumed that the profile distortions are caused by effects from the scintillator material. Following the experience in high energy physics, a simple model was developed which takes into account quenching effects of excitonic carriers inside a scintillator in a heuristic way. Based on this model, the observed beam profiles can be understood qualitatively. Together with the model description, first comparisons with experiments will be presented, and new scintillators suitable for beam profile diagnostics will be discussed.
	Slides WEOC03 [2.411 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEOC03
About •	paper received ※ 04 September 2018 paper accepted ※ 13 September 2018 issue date ※ 29 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPB10	Grating Scanner for Measurement of Micron-size Beam Profiles	448
	L.G. Sukhikh, A. Potylitsyn, S.A. Strokov TPU, Tomsk, Russia G. Kube, K. Wittenburg DESY, Hamburg, Germany
	Funding: The work was partly supported by the program ‘‘Nauka’ of the Russian Ministry of Education and Science, grant # 3.1903.2017 Wire scanners are widely used for transverse beam size diagnostics. The minimum detectable beam size is affected by the diameter of a single wire. The smallest carbon or tungsten wires used so far have diameters of about 4 microns. With the development of modern electron accelerators and the demands from future linear electron-positron colliders, sub-micron beam sizes have to be resolved. In order to increase the resolution, the decrease of the wire diameter is required. The authors of Ref. * proposed to manufacture thin gold stripes of rectangular shape (widths are equal to 1 µm or 2 µm and height is equal to 3 µm) on Si₃N₄ membrane. We propose to use another arrangement of gold stripes with varying period on a Si substrate. A set of 11 stripes with 1 µm width and 10 micron height with varying gap width in the range 3-0.25 µm ("grating scanner") was simulated by using an analytical model and by the Geant4 code. By moving this scanner across the beam one could measure the Bremsstrahlung yield vs. the coordinate, resulting in an oscillating dependence. The visibility of the resulting image allows defining the beam sizes in the range of 0.5-1.5 µm for the proposed scanner parameters. * S. Borrelli et al., "Generation and Measurement of Sub-Micrometer Relativistic Electron Beams", arXiv:1804.04252v1 [physics.acc-ph] 11 Apr 2018
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPB10
About •	paper received ※ 05 September 2018 paper accepted ※ 12 September 2018 issue date ※ 29 January 2019
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WEPB11	Spatial Resolution Improvement of OTR Monitors by Off-axis Light Collection	451
	A. Potylitsyn, A.I. Novokshonov, L.G. Sukhikh TPU, Tomsk, Russia G. Kube, A.I. Novokshonov DESY, Hamburg, Germany
	Funding: The work was partly supported by the program "Nauka" of the Russian Ministry of Education and Science, grant #3.1903.2017 The spatial resolution of an OTR monitor for electron beam profile diagnostics is determined by the resolution of the optical system and by the Point Spread Function (PSF) representing the single electron image. In the image plane, the PSF has a typical lobe-shape distribution with an inter-peak distance depending on wavelength and lens aperture ratio []. For a beam with a transverse rms size smaller than the distance, the reconstruction of the beam profile has several difficulties [, *]. We propose to reduce the PSF contribution and to improve the spatial resolution of an OTR monitor simply by rotating the lens optical axis with respect to the specular reflection direction. If the difference between the rotational angle and the lens aperture is much larger than the inverse Lorentz factor, the PSF has a Gaussian-like distribution which matches practically with the Airy distribution. Thus the resolution depends on wavelength and lens aperture. In principle, for lens apertures in the order of 0.1 rad such an approach should allow to measure beam sizes comparable to the wavelength of observation, using a simple deconvolution procedure for the measured image and the PSF. M. Castellano, V.Verzilov, Phys. Rev. ST-AB, 1 (1998). K.Kruchinin, S.T.Boogert, P.Karataev et al., Proc. IBIC 2013 (2013). * L.G. Sukhikh, A.P. Potylitsyn, G. Kube, Phys. Rev. AB 20 (2017).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPB11
About •	paper received ※ 04 September 2018 paper accepted ※ 11 September 2018 issue date ※ 29 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Upgrade and Status of Standard Diagnostic-Systems at FLASH and FLASHForward

13

N. Baboi, H.T. Duhme, O. Hensler, G. Kube, T. Lensch, D. Lipka, B. Lorbeer, Re. Neumann, P.A. Smirnov, T. Wamsat, M. Werner
DESY, Hamburg, Germany

Electron beam diagnostics plays a crucial role in the precise and reliable generation of ultra-short high bril-liance XUV and soft X-ray beams at the Free Electron Laser in Hamburg (FLASH). Most diagnostic systems monitor each of up to typically 600 bunches per beam, with a frequency of up to 1 MHz, a typical charge be-tween 0.1 and 1 nC and an energy of 350 to 1250 MeV. The diagnostic monitors have recently undergone a major upgrade. This process started several years ago with the development of monitors fulfilling the requirements of the European XFEL and of the FLASH2 undulator beamline and it continued with their installation and commissioning. Later they have been further improved and an upgrade was made in the old part of the linac. Also the FLASHForward plasma-wakefield acceleration experiment has been installed in the third beamline. This paper will give an overview of the upgrade of the BPM, Toroid and BLM systems, pointing out to their improved performance. Other systems underwent a partial upgrade, mainly by having their VME-based ADCs replaced with MTCA type. The overall status of the diagnostic will be reviewed.

Slides MOOB03 [2.728 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOOB03

About •

paper received ※ 05 September 2018 paper accepted ※ 12 September 2018 issue date ※ 29 January 2019

Export •

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

WEOC01

Summary of Emittance Measurements Workshop for SLS and FELs

U. Iriso
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
F. Ewald
ESRF, Grenoble, France
G. Kube, K. Wittenburg
DESY, Hamburg, Germany
T.M. Mitsuhashi
KEK, Ibaraki, Japan
V. Schlott
PSI, Villigen PSI, Switzerland

Funding: This project has received funding from the EU Horizon 2020 Research and Innovation programme, under Grant Agreement No 730871.
In January 2018, a Topical Workshop on Emittance Measurements for Synchrotron Light Sources and FELs was held at ALBA inside the ARIES network. This talk will summarize the state of the art of the different emittance measurements techniques for these type of accelerators, and will present the relevant topics shown during the workshop.

Slides WEOC01 [4.723 MB]

Export •

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

WEOC03

A Simple Model to Describe Smoke Ring Shaped Beam Profile Measurements With Scintillating Screens at the European XFEL

366

G. Kube, S. Liu, A.I. Novokshonov, M. Scholz
DESY, Hamburg, Germany

Standard beam profile measurements of high-brightness electron beams based on OTR may be hampered by coherence effects. Therefore it was decided for the European XFEL to measure transverse beam profiles based on scintillating screen monitors using LYSO:Ce. While it is possible to resolve beam sizes down to a few micrometers with this scintillator, the experience during the XFEL commissioning showed that the measured emittance values were significantly larger than the expected ones. In addition, beam profiles measured at bunch charges of a few hundred pC showed a ’smoke ring’ structure. While coherent OTR emission and beam dynamical influence can be excluded, it is assumed that the profile distortions are caused by effects from the scintillator material. Following the experience in high energy physics, a simple model was developed which takes into account quenching effects of excitonic carriers inside a scintillator in a heuristic way. Based on this model, the observed beam profiles can be understood qualitatively. Together with the model description, first comparisons with experiments will be presented, and new scintillators suitable for beam profile diagnostics will be discussed.

Slides WEOC03 [2.411 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEOC03

About •

paper received ※ 04 September 2018 paper accepted ※ 13 September 2018 issue date ※ 29 January 2019

Export •

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

WEPB10

Grating Scanner for Measurement of Micron-size Beam Profiles

448

L.G. Sukhikh, A. Potylitsyn, S.A. Strokov
TPU, Tomsk, Russia
G. Kube, K. Wittenburg
DESY, Hamburg, Germany

Funding: The work was partly supported by the program ‘‘Nauka’ of the Russian Ministry of Education and Science, grant # 3.1903.2017
Wire scanners are widely used for transverse beam size diagnostics. The minimum detectable beam size is affected by the diameter of a single wire. The smallest carbon or tungsten wires used so far have diameters of about 4 microns. With the development of modern electron accelerators and the demands from future linear electron-positron colliders, sub-micron beam sizes have to be resolved. In order to increase the resolution, the decrease of the wire diameter is required. The authors of Ref. * proposed to manufacture thin gold stripes of rectangular shape (widths are equal to 1 µm or 2 µm and height is equal to 3 µm) on Si₃N₄ membrane. We propose to use another arrangement of gold stripes with varying period on a Si substrate. A set of 11 stripes with 1 µm width and 10 micron height with varying gap width in the range 3-0.25 µm ("grating scanner") was simulated by using an analytical model and by the Geant4 code. By moving this scanner across the beam one could measure the Bremsstrahlung yield vs. the coordinate, resulting in an oscillating dependence. The visibility of the resulting image allows defining the beam sizes in the range of 0.5-1.5 µm for the proposed scanner parameters.
* S. Borrelli et al., "Generation and Measurement of Sub-Micrometer Relativistic Electron Beams", arXiv:1804.04252v1 [physics.acc-ph] 11 Apr 2018

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPB10

About •

paper received ※ 05 September 2018 paper accepted ※ 12 September 2018 issue date ※ 29 January 2019

Export •

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

WEPB11

Spatial Resolution Improvement of OTR Monitors by Off-axis Light Collection

451

A. Potylitsyn, A.I. Novokshonov, L.G. Sukhikh
TPU, Tomsk, Russia
G. Kube, A.I. Novokshonov
DESY, Hamburg, Germany

Funding: The work was partly supported by the program "Nauka" of the Russian Ministry of Education and Science, grant #3.1903.2017
The spatial resolution of an OTR monitor for electron beam profile diagnostics is determined by the resolution of the optical system and by the Point Spread Function (PSF) representing the single electron image. In the image plane, the PSF has a typical lobe-shape distribution with an inter-peak distance depending on wavelength and lens aperture ratio [*]. For a beam with a transverse rms size smaller than the distance, the reconstruction of the beam profile has several difficulties [**, ***]. We propose to reduce the PSF contribution and to improve the spatial resolution of an OTR monitor simply by rotating the lens optical axis with respect to the specular reflection direction. If the difference between the rotational angle and the lens aperture is much larger than the inverse Lorentz factor, the PSF has a Gaussian-like distribution which matches practically with the Airy distribution. Thus the resolution depends on wavelength and lens aperture. In principle, for lens apertures in the order of 0.1 rad such an approach should allow to measure beam sizes comparable to the wavelength of observation, using a simple deconvolution procedure for the measured image and the PSF.
* M. Castellano, V.Verzilov, Phys. Rev. ST-AB, 1 (1998).
** K.Kruchinin, S.T.Boogert, P.Karataev et al., Proc. IBIC 2013 (2013).
*** L.G. Sukhikh, A.P. Potylitsyn, G. Kube, Phys. Rev. AB 20 (2017).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPB11

About •

paper received ※ 04 September 2018 paper accepted ※ 11 September 2018 issue date ※ 29 January 2019

Export •

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