1
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Maltezopoulos T, Brinker F, Dietrich F, Freund W, Grünert J, Jastrow UF, Kujala N, Laksman J, Liu J, Tiedtke K, Tschentscher T. Hard X-ray operation of X-ray gas monitors at the European XFEL. JOURNAL OF SYNCHROTRON RADIATION 2024; 31:681-689. [PMID: 38838164 PMCID: PMC11226157 DOI: 10.1107/s160057752400331x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 04/16/2024] [Indexed: 06/07/2024]
Abstract
X-ray gas monitors (XGMs) are operated at the European XFEL for non-invasive single-shot pulse energy measurements and average beam-position monitoring. The underlying measurement principle is the photo-ionization of rare gas atoms at low gas pressures and the detection of the photo-ions and photo-electrons created. These are essential for tuning and sustaining self-amplified spontaneous emission (SASE) operation, machine radiation safety, and sorting single-shot experimental data according to pulse energy. In this paper, the first results from XGM operation at photon energies up to 30 keV are presented, which are far beyond the original specification of this device. Here, the Huge Aperture MultiPlier (HAMP) is used for single-shot pulse energy measurements since the standard X-ray gas monitor detectors (XGMDs) do not provide a sufficient signal-to-noise ratio, even at the highest operating gas pressures. A single-shot correlation coefficient of 0.98 is measured between consecutive XGMs operated with HAMP, which is as good as measuring with the standard XGMD detectors. An intra-train non-linearity of the HAMP signal is discovered, and operation parameters to mitigate this effect are studied. The upper repetition rate limit of HAMP operation at 2.25 MHz is also determined. Finally, the possibilities and limits for future XGM operation at photon energies up to 50 keV are discussed.
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Affiliation(s)
| | - Frank Brinker
- Deutsches Elektronen-Synchrotron DESYNotkestrasse 8522607HamburgGermany
| | | | | | - Jan Grünert
- European XFELHolzkoppel 422869SchenefeldGermany
| | - Ulf Fini Jastrow
- Deutsches Elektronen-Synchrotron DESYNotkestrasse 8522607HamburgGermany
| | | | | | - Jia Liu
- European XFELHolzkoppel 422869SchenefeldGermany
| | - Kai Tiedtke
- Deutsches Elektronen-Synchrotron DESYNotkestrasse 8522607HamburgGermany
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2
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Keitel B, Chalupský J, Jelínek Š, Burian T, Dziarzhytski S, Hájková V, Juha L, Kuglerová Z, Kuhlmann M, Mann K, Ruiz-Lopez M, Schäfer B, Vozda V, Wodzinski T, Yurkov MV, Plönjes E. Comparison of wavefront sensing and ablation imprinting for FEL focus diagnostics at FLASH2. OPTICS EXPRESS 2024; 32:21532-21552. [PMID: 38859505 DOI: 10.1364/oe.527418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 05/18/2024] [Indexed: 06/12/2024]
Abstract
Extreme ultraviolet (EUV) photon beam characterization techniques, Hartmann wavefront sensing and single shot ablation imprinting, were compared along the caustic of a tightly focused free-electron laser (FEL) beam at beamline FL24 of FLASH2, the Free-electron LASer in Hamburg at DESY. The transverse coherence of the EUV FEL was determined by a Young's double pinhole experiment and used in a back-propagation algorithm which includes partial coherence to calculate the beam intensity profiles along the caustic from the wavefront measurements. A very good agreement of the profile structure and size is observed for different wavelengths between the back-propagated profiles, an indirect technique, and ablation imprints. As a result, the Hartmann wavefront sensor including its software MrBeam is a very useful, single shot pulse resolved and fast tool for non-invasive determination of focal spot size and shape and also for beam profiles along the caustic.
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3
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Hönicke P, Wählisch A, Unterumsberger R, Beckhoff B, Bogdanowicz J, Charley AL, Mertens H, Rochat N, Hartmann JM, Giambacorti N. Reference-free x-ray fluorescence analysis with a micrometer-sized incident beam. NANOTECHNOLOGY 2024; 35:285702. [PMID: 38579688 DOI: 10.1088/1361-6528/ad3aff] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 04/05/2024] [Indexed: 04/07/2024]
Abstract
Spatially resolved x-ray fluorescence (XRF) based analysis employing incident beam sizes in the low micrometer range (μXRF) is widely used to study lateral composition changes of various types of microstructured samples. However, up to now the quantitative analysis of such experimental datasets could only be realized employing adequate calibration or reference specimen. In this work, we extent the applicability of the so-called reference-free XRF approach to enable reference-freeμXRF analysis. Here, no calibration specimen are needed in order to derive a quantitative and position sensitive composition of the sample of interest. The necessary instrumental steps to realize reference-freeμXRF are explained and a validation of ref.-freeμXRF against ref.-free standard XRF is performed employing laterally homogeneous samples. Finally, an application example from semiconductor research is shown, where the lateral sample features require the usage of ref.-freeμXRF for quantitative analysis.
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Affiliation(s)
- Philipp Hönicke
- Physikalisch-Technische Bundesanstalt (PTB) Abbestr. 2-12 D-10587 Berlin, Germany
| | - André Wählisch
- Physikalisch-Technische Bundesanstalt (PTB) Abbestr. 2-12 D-10587 Berlin, Germany
| | | | - Burkhard Beckhoff
- Physikalisch-Technische Bundesanstalt (PTB) Abbestr. 2-12 D-10587 Berlin, Germany
| | | | | | | | - Névine Rochat
- Univ. Grenoble Alpes CEA, Leti F-38000 Grenoble, France
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4
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Wang G, Dijkstal P, Reiche S, Schnorr K, Prat E. Millijoule Femtosecond X-Ray Pulses from an Efficient Fresh-Slice Multistage Free-Electron Laser. PHYSICAL REVIEW LETTERS 2024; 132:035002. [PMID: 38307082 DOI: 10.1103/physrevlett.132.035002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/18/2023] [Indexed: 02/04/2024]
Abstract
We present the generation of x-ray pulses with average pulse energies up to one millijoule and rms pulse durations down to the femtosecond level. We have produced these intense and short pulses by employing the fresh-slice multistage amplification scheme with a transversely tilted electron beam in a free-electron laser. In this scheme, a short pulse is produced in the first stage and later amplified by fresh parts of the electron bunch in up to a total of four stages of amplification. Our implementation is efficient, since practically the full electron beam contributes to produce the x-ray pulse. Our implementation is also compact, utilizing only 32 m of undulator. The demonstration was done at Athos, the soft x-ray beamline of SwissFEL, which was designed with high flexibility to take full advantage of the multistage amplification scheme. It opens the door for scientific opportunities following ultrafast dynamics using nonlinear x-ray spectroscopy techniques or avoiding electronic damage when capturing structures with a single intense pulse via single-particle imaging.
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Affiliation(s)
- Guanglei Wang
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | | | - Sven Reiche
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | | | - Eduard Prat
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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5
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Prat E, Al Haddad A, Arrell C, Augustin S, Boll M, Bostedt C, Calvi M, Cavalieri AL, Craievich P, Dax A, Dijkstal P, Ferrari E, Follath R, Ganter R, Geng Z, Hiller N, Huppert M, Ischebeck R, Juranić P, Kittel C, Knopp G, Malyzhenkov A, Marcellini F, Neppl S, Reiche S, Sammut N, Schietinger T, Schmidt T, Schnorr K, Trisorio A, Vicario C, Voulot D, Wang G, Weilbach T. An X-ray free-electron laser with a highly configurable undulator and integrated chicanes for tailored pulse properties. Nat Commun 2023; 14:5069. [PMID: 37604879 PMCID: PMC10442322 DOI: 10.1038/s41467-023-40759-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 08/09/2023] [Indexed: 08/23/2023] Open
Abstract
X-ray free-electron lasers (FELs) are state-of-the-art scientific tools capable to study matter on the scale of atomic processes. Since the initial operation of X-ray FELs more than a decade ago, several facilities with upgraded performance have been put in operation. Here we present the first lasing results of Athos, the soft X-ray FEL beamline of SwissFEL at the Paul Scherrer Institute in Switzerland. Athos features an undulator layout based on short APPLE-X modules providing full polarisation control, interleaved with small magnetic chicanes. This versatile configuration allows for many operational modes, giving control over many FEL properties. We show, for example, a 35% reduction of the required undulator length to achieve FEL saturation with respect to standard undulator configurations. We also demonstrate the generation of more powerful pulses than the ones obtained in typical undulators. Athos represents a fundamental step forward in the design of FEL facilities, creating opportunities in FEL-based sciences.
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Affiliation(s)
- Eduard Prat
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland.
| | | | | | - Sven Augustin
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Marco Boll
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Christoph Bostedt
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
- Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - Marco Calvi
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Adrian L Cavalieri
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
- Institute of Applied Physics, University of Bern, CH-3012, Bern, Switzerland
| | | | - Andreas Dax
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | | | - Eugenio Ferrari
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
- Deutsches Elektronen-Synchrotron, D-22607, Hamburg, Germany
| | - Rolf Follath
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Romain Ganter
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Zheqiao Geng
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Nicole Hiller
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Martin Huppert
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | | | - Pavle Juranić
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Christoph Kittel
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
- University of Malta, MSD2080, Msida, Malta
| | - Gregor Knopp
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Alexander Malyzhenkov
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
- CERN, CH-1211, Geneva 23, Switzerland
| | | | - Stefan Neppl
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Sven Reiche
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | | | | | - Thomas Schmidt
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | | | | | - Carlo Vicario
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Didier Voulot
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
| | - Guanglei Wang
- Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland
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6
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Chalupský J, Vozda V, Hering J, Kybic J, Burian T, Dziarzhytski S, Frantálová K, Hájková V, Jelínek Š, Juha L, Keitel B, Kuglerová Z, Kuhlmann M, Petryshak B, Ruiz-Lopez M, Vyšín L, Wodzinski T, Plönjes E. Deep learning for laser beam imprinting. OPTICS EXPRESS 2023; 31:19703-19721. [PMID: 37381380 DOI: 10.1364/oe.481776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 05/10/2023] [Indexed: 06/30/2023]
Abstract
Methods of ablation imprints in solid targets are widely used to characterize focused X-ray laser beams due to a remarkable dynamic range and resolving power. A detailed description of intense beam profiles is especially important in high-energy-density physics aiming at nonlinear phenomena. Complex interaction experiments require an enormous number of imprints to be created under all desired conditions making the analysis demanding and requiring a huge amount of human work. Here, for the first time, we present ablation imprinting methods assisted by deep learning approaches. Employing a multi-layer convolutional neural network (U-Net) trained on thousands of manually annotated ablation imprints in poly(methyl methacrylate), we characterize a focused beam of beamline FL24/FLASH2 at the Free-electron laser in Hamburg. The performance of the neural network is subject to a thorough benchmark test and comparison with experienced human analysts. Methods presented in this Paper pave the way towards a virtual analyst automatically processing experimental data from start to end.
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7
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Juranić P, Alarcon A, Ischebeck R. Online absolute calibration of fast FEL pulse energy measurements. JOURNAL OF SYNCHROTRON RADIATION 2023; 30:500-504. [PMID: 36897394 PMCID: PMC10161891 DOI: 10.1107/s1600577523001133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/07/2023] [Indexed: 05/06/2023]
Abstract
One of the challenges facing modern free-electron laser (FEL) facilities is the accurate pulse-to-pulse online measurement of the absolute flux of the X-ray pulses, for use by both machine operators for optimization and users of the photon beam to better understand their data. This manuscript presents a methodology that combines existing slow-measurement methods currently used in gas detectors across the world and fast uncalibrated signals from multipliers, meant for relative flux pulse-to-pulse measurements, which create a shot-to-shot absolute flux measurement through the use of sensor-based conditional triggers and algorithms at SwissFEL.
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Affiliation(s)
- Pavle Juranić
- Paul Scherrer Institut, Forschungsstrasse 111, Villigen 5232, Switzerland
| | - Arturo Alarcon
- Paul Scherrer Institut, Forschungsstrasse 111, Villigen 5232, Switzerland
| | - Rasmus Ischebeck
- Paul Scherrer Institut, Forschungsstrasse 111, Villigen 5232, Switzerland
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8
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Mazza T, Baumann TM, Boll R, De Fanis A, Grychtol P, Ilchen M, Montaño J, Music V, Ovcharenko Y, Rennhack N, Rivas DE, Rörig A, Schmidt P, Usenko S, Ziołkowski P, La Civita D, Vannoni M, Sinn H, Keitel B, Plönjes E, Jastrow UF, Sorokin A, Tiedtke K, Mann K, Schäfer B, Breckwoldt N, Son SK, Meyer M. The beam transport system for the Small Quantum Systems instrument at the European XFEL: optical layout and first commissioning results. JOURNAL OF SYNCHROTRON RADIATION 2023; 30:457-467. [PMID: 36891860 PMCID: PMC10000793 DOI: 10.1107/s1600577522012085] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 12/22/2022] [Indexed: 06/18/2023]
Abstract
The Small Quantum Systems instrument is one of the six operating instruments of the European XFEL, dedicated to the atomic, molecular and cluster physics communities. The instrument started its user operation at the end of 2018 after a commissioning phase. The design and characterization of the beam transport system are described here. The X-ray optical components of the beamline are detailed, and the beamline performances, transmission and focusing capabilities are reported. It is shown that the X-ray beam can be effectively focused as predicted by ray-tracing simulations. The impact of non-ideal X-ray source conditions on the focusing performances is discussed.
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Affiliation(s)
- Tommaso Mazza
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - Rebecca Boll
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | - Markus Ilchen
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | | | - Valerija Music
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Department of Physics, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | | | - Nils Rennhack
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | | | - Sergey Usenko
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | | | - Harald Sinn
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Barbara Keitel
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Elke Plönjes
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Ulf Fini Jastrow
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Andrey Sorokin
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Kai Tiedtke
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Klaus Mann
- IFNANO Institut für Nanophotonik Göttingen e.V., Hans-Adolf-Krebs-Weg 1, 37077 Göttingen, Germany
| | - Bernd Schäfer
- IFNANO Institut für Nanophotonik Göttingen e.V., Hans-Adolf-Krebs-Weg 1, 37077 Göttingen, Germany
| | - Niels Breckwoldt
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Department of Physics, Universität Hamburg, Notkestr. 9–11, 22607 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Sang-Kil Son
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Michael Meyer
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
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9
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Unsupervised real-world knowledge extraction via disentangled variational autoencoders for photon diagnostics. Sci Rep 2022; 12:20783. [PMID: 36456706 PMCID: PMC9715554 DOI: 10.1038/s41598-022-25249-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
We present real-world data processing on measured electron time-of-flight data via neural networks. Specifically, the use of disentangled variational autoencoders on data from a diagnostic instrument for online wavelength monitoring at the free electron laser FLASH in Hamburg. Without a-priori knowledge the network is able to find representations of single-shot FEL spectra, which have a low signal-to-noise ratio. This reveals, in a directly human-interpretable way, crucial information about the photon properties. The central photon energy and the intensity as well as very detector-specific features are identified. The network is also capable of data cleaning, i.e. denoising, as well as the removal of artefacts. In the reconstruction, this allows for identification of signatures with very low intensity which are hardly recognisable in the raw data. In this particular case, the network enhances the quality of the diagnostic analysis at FLASH. However, this unsupervised method also has the potential to improve the analysis of other similar types of spectroscopy data.
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10
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Laksman J, Dietrich F, Liu J, Maltezopoulos T, Planas M, Freund W, Gautam R, Kujala N, Francoual S, Grünert J. Development of a photoelectron spectrometer for hard x-ray photon diagnostics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:115111. [PMID: 36461550 DOI: 10.1063/5.0097525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/21/2022] [Indexed: 06/17/2023]
Abstract
The development and characterization of an angle-resolved photoelectron spectrometer, based on the electron time-of-flight concept, for hard x-ray photon diagnostics at the European Free-Electron Laser, are described. The instrument is meant to provide users and operators with pulse-resolved, non-invasive spectral distribution diagnostics, which in the hard x-ray regime is a challenge due to the poor cross-section and high kinetic energy of photoelectrons for the available target gases. We report on the performances of this instrument as obtained using hard x-rays at the PETRA III synchrotron at DESY in multibunch mode. Results are compared with electron trajectory simulations. We demonstrate a resolving power of 10 eV at incident photon energies up to at least 20 keV.
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Affiliation(s)
| | | | - Jia Liu
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - Marc Planas
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | - Naresh Kujala
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Jan Grünert
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
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11
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Rottke H, Engel RY, Schick D, Schunck JO, Miedema PS, Borchert MC, Kuhlmann M, Ekanayake N, Dziarzhytski S, Brenner G, Eichmann U, von Korff Schmising C, Beye M, Eisebitt S. Probing electron and hole colocalization by resonant four-wave mixing spectroscopy in the extreme ultraviolet. SCIENCE ADVANCES 2022; 8:eabn5127. [PMID: 35594356 PMCID: PMC9122317 DOI: 10.1126/sciadv.abn5127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/05/2022] [Indexed: 06/15/2023]
Abstract
Extending nonlinear spectroscopic techniques into the x-ray domain promises unique insight into photoexcited charge dynamics, which are of fundamental and applied interest. We report on the observation of a third-order nonlinear process in lithium fluoride (LiF) at a free-electron laser. Exploring the yield of four-wave mixing (FWM) in resonance with transitions to strongly localized core exciton states versus delocalized Bloch states, we find resonant FWM to be a sensitive probe for the degree of charge localization: Substantial sum- and difference-frequency generation is observed exclusively when in a one- or three-photon resonance with a LiF core exciton, with a dipole forbidden transition affecting details of the nonlinear response. Our reflective geometry-based approach to detect FWM signals enables the study of a wide variety of condensed matter sample systems, provides atomic selectivity via resonant transitions, and can be easily scaled to shorter wavelengths at free-electron x-ray lasers.
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Affiliation(s)
- Horst Rottke
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Robin Y. Engel
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Daniel Schick
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Jan O. Schunck
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Piter S. Miedema
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Martin C. Borchert
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Marion Kuhlmann
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Nagitha Ekanayake
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | | | - Günter Brenner
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Ulrich Eichmann
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Clemens von Korff Schmising
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
| | - Martin Beye
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Stefan Eisebitt
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, 12489 Berlin, Germany
- Technische Universität Berlin, Institut für Optik und Atomare Physik, Straße des 17. Juni 135, 10623 Berlin, Germany
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12
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Liu Z, Deng B, Deng H, Liu B. Numerical study of transverse position monitor and compensation for x-ray polarization diagnosis. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:113104. [PMID: 34852524 DOI: 10.1063/5.0054804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
Diagnosing free electron laser (FEL) polarization is critical for polarization-modulated research such as x-ray FEL diffraction imaging and probing material magnetism. In an electron time-of-flight (eTOF) polarimeter, the flight time and angular distribution of photoelectrons were designed based on x-ray polarimetry for on-site diagnosis. However, the transverse position of x-ray FEL pulses introduces error into the measured photoelectron angular distribution. This work, thus, proposes a method of compensating transverse position jitters for the polarization by the eTOF polarimeter itself without an external x-ray beam-position monitor. A comprehensive numerical model is developed to demonstrate the feasibility of the compensation method, and the results reveal that a spatial resolution of 20 μm and a polarity improved by 0.02 are possible with fully polarized FEL pulses. The impact of FEL pulses and a method to calibrate their linearity are also discussed.
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Affiliation(s)
- Zipeng Liu
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 201800 Shanghai, China
| | - Bangjie Deng
- School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, 710049 Shaanxi, China
| | - Haixiao Deng
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, 201210 Shanghai, China
| | - Bo Liu
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, 201210 Shanghai, China
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13
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Zastrau U, Appel K, Baehtz C, Baehr O, Batchelor L, Berghäuser A, Banjafar M, Brambrink E, Cerantola V, Cowan TE, Damker H, Dietrich S, Di Dio Cafiso S, Dreyer J, Engel HO, Feldmann T, Findeisen S, Foese M, Fulla-Marsa D, Göde S, Hassan M, Hauser J, Herrmannsdörfer T, Höppner H, Kaa J, Kaever P, Knöfel K, Konôpková Z, Laso García A, Liermann HP, Mainberger J, Makita M, Martens EC, McBride EE, Möller D, Nakatsutsumi M, Pelka A, Plueckthun C, Prescher C, Preston TR, Röper M, Schmidt A, Seidel W, Schwinkendorf JP, Schoelmerich MO, Schramm U, Schropp A, Strohm C, Sukharnikov K, Talkovski P, Thorpe I, Toncian M, Toncian T, Wollenweber L, Yamamoto S, Tschentscher T. The High Energy Density Scientific Instrument at the European XFEL. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:1393-1416. [PMID: 34475288 PMCID: PMC8415338 DOI: 10.1107/s1600577521007335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
The European XFEL delivers up to 27000 intense (>1012 photons) pulses per second, of ultrashort (≤50 fs) and transversely coherent X-ray radiation, at a maximum repetition rate of 4.5 MHz. Its unique X-ray beam parameters enable groundbreaking experiments in matter at extreme conditions at the High Energy Density (HED) scientific instrument. The performance of the HED instrument during its first two years of operation, its scientific remit, as well as ongoing installations towards full operation are presented. Scientific goals of HED include the investigation of extreme states of matter created by intense laser pulses, diamond anvil cells, or pulsed magnets, and ultrafast X-ray methods that allow their diagnosis using self-amplified spontaneous emission between 5 and 25 keV, coupled with X-ray monochromators and optional seeded beam operation. The HED instrument provides two target chambers, X-ray spectrometers for emission and scattering, X-ray detectors, and a timing tool to correct for residual timing jitter between laser and X-ray pulses.
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Affiliation(s)
- Ulf Zastrau
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Karen Appel
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Carsten Baehtz
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Oliver Baehr
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | | | - Mohammadreza Banjafar
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | | | - Thomas E. Cowan
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Horst Damker
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | | | | | - Jörn Dreyer
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Hans-Olaf Engel
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | | | - Manon Foese
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | | | | | - Mohammed Hassan
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Jens Hauser
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | - Hauke Höppner
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Johannes Kaa
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Technische Universität Dortmund, 44227 Dortmund, Germany
| | - Peter Kaever
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Klaus Knöfel
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | | | | | - Jona Mainberger
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - Mikako Makita
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - Emma E. McBride
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Dominik Möller
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | - Alexander Pelka
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | | | | | - Michael Röper
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | | | - Wolfgang Seidel
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | | | - Ulrich Schramm
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Andreas Schropp
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | | | | | - Peter Talkovski
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - Ian Thorpe
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Monika Toncian
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | - Toma Toncian
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
| | | | - Shingo Yamamoto
- Helmholtz-Zentrum Dresden-Rossendorf eV, 01328 Dresden, Germany
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14
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Engel RY, Ekimova M, Miedema PS, Kleine C, Ludwig J, Ochmann M, Grimm-Lebsanft B, Ma R, Teubner M, Dziarzhytski S, Brenner G, Czwalinna MK, Rösner B, Kim TK, David C, Herres-Pawlis S, Rübhausen M, Nibbering ETJ, Huse N, Beye M. Shot noise limited soft x-ray absorption spectroscopy in solution at a SASE-FEL using a transmission grating beam splitter. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:014303. [PMID: 33564694 PMCID: PMC7847311 DOI: 10.1063/4.0000049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
X-ray absorption near-edge structure (XANES) spectroscopy provides element specificity and is a powerful experimental method to probe local unoccupied electronic structures. In the soft x-ray regime, it is especially well suited for the study of 3d-metals and light elements such as nitrogen. Recent developments in vacuum-compatible liquid flat jets have facilitated soft x-ray transmission spectroscopy on molecules in solution, providing information on valence charge distributions of heteroatoms and metal centers. Here, we demonstrate XANES spectroscopy of molecules in solution at the nitrogen K-edge, performed at FLASH, the Free-Electron Laser (FEL) in Hamburg. A split-beam referencing scheme optimally characterizes the strong shot-to-shot fluctuations intrinsic to the process of self-amplified spontaneous emission on which most FELs are based. Due to this normalization, a sensitivity of 1% relative transmission change is achieved, limited by fundamental photon shot noise. The effective FEL bandwidth is increased by streaking the electron energy over the FEL pulse train to measure a wider spectral window without changing FEL parameters. We propose modifications to the experimental setup with the potential of improving the instrument sensitivity by two orders of magnitude, thereby exploiting the high peak fluence of FELs to enable unprecedented sensitivity for femtosecond XANES spectroscopy on liquids in the soft x-ray spectral region.
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Affiliation(s)
- Robin Y. Engel
- Deutsches Elektronen Synchrotron DESY, 22607 Hamburg, Germany
| | - Maria Ekimova
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | | | - Carlo Kleine
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Jan Ludwig
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Miguel Ochmann
- Institut for Nanostructure and Solid-State Physics, CFEL, University of Hamburg, 22761 Hamburg, Germany
| | - Benjamin Grimm-Lebsanft
- Institut for Nanostructure and Solid-State Physics, CFEL, University of Hamburg, 22761 Hamburg, Germany
| | - Rory Ma
- Institut for Nanostructure and Solid-State Physics, CFEL, University of Hamburg, 22761 Hamburg, Germany
| | | | | | - Günter Brenner
- Deutsches Elektronen Synchrotron DESY, 22607 Hamburg, Germany
| | | | | | - Tae Kyu Kim
- Department of Chemistry, Yonsei University, 03722 Seoul, South Korea
| | | | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry, RWTH Aachen University, 52074 Aachen, Germany
| | - Michael Rübhausen
- Institut for Nanostructure and Solid-State Physics, CFEL, University of Hamburg, 22761 Hamburg, Germany
| | - Erik T. J. Nibbering
- Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Nils Huse
- Institut for Nanostructure and Solid-State Physics, CFEL, University of Hamburg, 22761 Hamburg, Germany
| | - Martin Beye
- Deutsches Elektronen Synchrotron DESY, 22607 Hamburg, Germany
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15
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Parallel Broadband Femtosecond Reflection Spectroscopy at a Soft X-Ray Free-Electron Laser. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10196947] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
X-ray absorption spectroscopy (XAS) and the directly linked X-ray reflectivity near absorption edges yield a wealth of specific information on the electronic structure around the resonantly addressed element. Observing the dynamic response of complex materials to optical excitations in pump–probe experiments requires high sensitivity to small changes in the spectra which in turn necessitates the brilliance of free electron laser (FEL) pulses. However, due to the fluctuating spectral content of pulses generated by self-amplified spontaneous emission (SASE), FEL experiments often struggle to reach the full sensitivity and time-resolution that FELs can in principle enable. Here, we implement a setup which solves two common challenges in this type of spectroscopy using FELs: First, we achieve a high spectral resolution by using a spectrometer downstream of the sample instead of a monochromator upstream of the sample. Thus, the full FEL bandwidth contributes to the measurement at the same time, and the FEL pulse duration is not elongated by a monochromator. Second, the FEL beam is divided into identical copies by a transmission grating beam splitter so that two spectra from separate spots on the sample (or from the sample and known reference) can be recorded in-parallel with the same spectrometer, enabling a spectrally resolved intensity normalization of pulse fluctuations in pump–probe scenarios. We analyze the capabilities of this setup around the oxygen K- and nickel L-edges recorded with third harmonic radiation of the free electron laser in Hamburg (FLASH), demonstrating the capability for pump–probe measurements with sensitivity to reflectivity changes on the per mill level.
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16
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Kujala N, Freund W, Liu J, Koch A, Falk T, Planas M, Dietrich F, Laksman J, Maltezopoulos T, Risch J, Dall'Antonia F, Grünert J. Hard x-ray single-shot spectrometer at the European X-ray Free-Electron Laser. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:103101. [PMID: 33138553 DOI: 10.1063/5.0019935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/12/2020] [Indexed: 06/11/2023]
Abstract
The European X-ray Free-Electron Laser Facility in Germany delivers x-ray pulses with femtosecond pulse duration at a repetition rate of up to 4.5 MHz. The free-electron laser radiation is created by the self-amplified spontaneous emission (SASE) process, whose stochastic nature gives rise to shot-to-shot fluctuations in most beam properties, including spectrum, pulse energy, spatial profile, wavefront, and temporal profile. Each spectrum consisting of many spikes varies in width and amplitude that appear differently within the envelope of the SASE spectrum. In order to measure and study the SASE spectrum, the HIgh REsolution hard X-ray single-shot (HIREX) spectrometer was installed in the photon tunnel of the SASE1 undulator beamline. It is based on diamond gratings, bent crystals as a dispersive element, and a MHz-repetition-rate strip detector. It covers a photon energy range of 3 keV-25 keV and a bandwidth of 0.5% of the SASE beam. The SASE spikes are resolved with 0.15 eV separation using the Si 440 reflection, providing a resolving power of 60 000 at a photon energy of 9.3 keV. The measured SASE bandwidth is 25 eV. In this paper, we discuss the design specifications, installation, and commissioning of the HIREX spectrometer. The spectral results using Si (110), Si (111), and C (110) crystals are presented.
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Affiliation(s)
- Naresh Kujala
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Wolfgang Freund
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Jia Liu
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Andreas Koch
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Torben Falk
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Marc Planas
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Florian Dietrich
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Joakim Laksman
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | - Johannes Risch
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Fabio Dall'Antonia
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Jan Grünert
- European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
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17
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Zheng W, Jia L, Huang F. Vacuum-Ultraviolet Photon Detections. iScience 2020; 23:101145. [PMID: 32446223 PMCID: PMC7243193 DOI: 10.1016/j.isci.2020.101145] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 11/17/2022] Open
Abstract
Vacuum-ultraviolet (VUV) photon detection technology is an effective means for the exploration in the field of space science (monitoring the formation and evolution of solar storms), high-energy physics (dark matter detection), large-scale scientific facility (VUV free electron lasers) and electronic industry (high-resolution lithography). The advancement of this technology mainly depends on the performance optimization of VUV photodetectors. In this review, we introduced the research progress on the typical VUV photodetectors based on scintillator, photomultiplier tube, semiconductor, and gas, with their unique advantages and optimal performance indicators in different applications summarized. In particular, during recent years, thanks to the advances in ultra-wide bandgap semiconductors, economical VUV photodetectors with low power consumption and small size have been encouragingly developed. Finally, we pointed out the remaining challenges for each type of VUV detector, with the aim of maximizing the performance in a variety of applications in the future.
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Affiliation(s)
- Wei Zheng
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China.
| | - Lemin Jia
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China
| | - Feng Huang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China
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18
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Opportunities for Two-Color Experiments in the Soft X-ray Regime at the European XFEL. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10082728] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
X-ray pump/X-ray probe applications are made possible at X-ray Free Electron Laser (XFEL) facilities by generating two X-ray pulses with different wavelengths and controllable temporal delay. In order to enable this capability at the European XFEL, an upgrade project to equip the soft X-ray SASE3 beamline with a magnetic chicane is underway. In the present paper we describe the status of the project, its scientific focus and expected performance, including start-to-end simulations of the photon beam transport up to the sample, as well as recent experimental results demonstrating two-color lasing at photon energies of 805 eV + 835 eV and 910 eV + 950 eV. Additionally, we discuss methods to analyze the spectral properties and the intensity of the generated radiation to provide on-line diagnostics for future user experiments.
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19
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Jia L, Zheng W, Lin R, Huang F. Ultra-high Photovoltage (2.45 V) Forming in Graphene Heterojunction via Quasi-Fermi Level Splitting Enhanced Effect. iScience 2020; 23:100818. [PMID: 32004991 PMCID: PMC6995729 DOI: 10.1016/j.isci.2020.100818] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/19/2019] [Accepted: 01/02/2020] [Indexed: 11/05/2022] Open
Abstract
Owing to the fast response speed and low energy consumption, photovoltaic vacuum-ultraviolet (VUV) photodetectors show prominent advantages in the field of space science, high-energy physics, and electronics industry. For photovoltaic devices, it is imperative to boost their open-circuit voltage, which is the most direct indicator to measure the photoelectric conversion capability. In this report, a quasi-Fermi level splitting enhanced effect under illumination, benefiting from the variable Fermi level of graphene, is proposed to significantly increase the potential difference up to 2.45 V between the two ends of p-Gr/i-AlN/n-SiC heterojunction photovoltaic device. In addition, the highest external quantum efficiency of 56.1% (under the VUV irradiation of 172 nm) at 0 V bias and the ultra-fast photoresponse of 45 ns further demonstrate the superiority of high-open-circuit-voltage devices. The proposed device design strategy and the adopted effect provide a referential way for the construction of various photovoltaic devices. An open-circuit voltage up to 2.45 V is achieved by the graphene heterojunction device An efficient band assembly is designed to induce the larger quasi-Fermi level splitting An EQE as high as 56.1% (172 nm) and a rise time as short as 45 ns are achieved The adopted effect provides a referential way for various photovoltaic devices
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Affiliation(s)
- Lemin Jia
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China
| | - Wei Zheng
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China.
| | - Richeng Lin
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China
| | - Feng Huang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials, Sun Yat-sen University, Guangzhou 510275, China
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20
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Juranic P, Tiedtke K, Owada S, Tanaka T, Jastrow U, Sorokin A, Patthey L, Mankowsky R, Degenhardt M, Arbelo Y, Arrell C, Smedley J, Bohon J, Follath R. Transmission measurement at the Bernina branch of the Aramis Beamline of SwissFEL. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:2081-2085. [PMID: 31721754 PMCID: PMC6853380 DOI: 10.1107/s1600577519013237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 09/26/2019] [Indexed: 05/22/2023]
Abstract
The transmission of the optical components of the Bernina branch of the Aramis beamline at SwissFEL has been measured with an X-ray gas monitor from DESY and compared with a PSI gas detector upstream of the optical components. The transmission efficiencies of the Mo, Si and SiC mirror coatings of the Aramis beamline and the various other in-beam components were evaluated and compared with theoretical calculations, showing an agreement of 6% or better in all cases. The experiment has also shown the efficacy of the high-harmonic rejection mirrors at the Bernina branch of the Aramis beamline at SwissFEL, and characterized the transmission efficiency of the on-line spectrometer in the Aramis beamline. The theoretical transmission of the mirror coatings match the experimental data to within 7%. The accuracy of these measurements was checked against a radiative bolometer from a Japanese collaboration and found to agree to a level of 4% or better. Further comparisons with a diamond detector from a US-based inter-institute collaboration demonstrated a good agreement for the attenuator settings of the beamline.
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Affiliation(s)
- Pavle Juranic
- Paul Scherrer Institut, Villigen 5232, Switzerland
- Correspondence e-mail:
| | - Kai Tiedtke
- DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Shigeki Owada
- Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Takahiro Tanaka
- National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568, Japan
| | - Ulf Jastrow
- DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | | | - Luc Patthey
- Paul Scherrer Institut, Villigen 5232, Switzerland
| | | | | | | | | | - John Smedley
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Jen Bohon
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Rolf Follath
- Paul Scherrer Institut, Villigen 5232, Switzerland
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21
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Koch A, Risch J, Freund W, Maltezopoulos T, Planas M, Grünert J. Operation of photon diagnostic imagers for beam commissioning at the European XFEL. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1489-1495. [PMID: 31490136 DOI: 10.1107/s1600577519008737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 06/19/2019] [Indexed: 06/10/2023]
Abstract
X-ray photon beam diagnostic imagers are located at 24 positions in the European XFEL beam transport system to characterize the X-ray beam properties, and to give feedback for tuning and optimization of the electron acceleration and orbit, the undulators, and the X-ray optics. One year of commissioning allowed experience to be gained with these imagers, which will be reported here. The sensitive Spontaneous Radiation imager is useful for various investigations in spontaneous radiation mode: for undulator adjustments and for low-signal imaging applications. The high-resolution Free-Electron Laser imager, 10 µm spatial resolution, is extensively used for the monitoring of beam position, spot size and shape, gain curve measurements, and also for beam-intensity monitoring. The wide field-of-view pop-in monitors (up to 200 mm) are regularly used for alignment and tuning of the various X-ray optical components like mirrors, slits and monochromators, and also for on-line beam control of a stable beam position at the instruments. The Exit Slit imager after the soft X-ray monochromator provides spectral information of the beam together with multi-channel plate based single-pulse gating. For particular use cases, these special features of the imagers are described. Some radiation-induced degradation of scintillators took place in this initial commissioning phase, providing useful information for better understanding of damage thresholds. Visible-light radiation in the beam pipe generated by upstream bending magnets caused spurious reflections in the optical system of some of the imagers which can be suppressed by aluminium-coated scintillating screens.
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22
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Maltezopoulos T, Dietrich F, Freund W, Jastrow UF, Koch A, Laksman J, Liu J, Planas M, Sorokin AA, Tiedtke K, Grünert J. Operation of X-ray gas monitors at the European XFEL. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1045-1051. [PMID: 31274426 DOI: 10.1107/s1600577519003795] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/19/2019] [Indexed: 06/09/2023]
Abstract
X-ray gas monitors (XGMs) are operated at the European XFEL for non-invasive single-shot pulse energy measurements and average beam position monitoring. They are used for tuning and maintaining the self-amplified spontaneous emission (SASE) operation and for sorting single-shot experimental data according to the pulse-resolved energy monitor data. The XGMs were developed at DESY based on the specific requirements for the European XFEL. In total, six XGM units are continuously in operation. Here, the main principle and experimental setup of an XGM are summarized, and the locations of the six XGMs at the facility are shown. Pulse energy measurements at 0.134 nm wavelength are presented, exceeding 1 mJ obtained with an absolute measurement uncertainty of 7-10%; correlations between different XGMs are shown, from which a SASE1 beamline transmission of 97% is deduced. Additionally, simultaneous position measurements close to the undulator and at the end of the tunnel are shown, along with the correlation of beam position data simultaneously acquired by an XGM and an imager.
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Affiliation(s)
| | - Florian Dietrich
- X-ray Photon Diagnostics Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Wolfgang Freund
- X-ray Photon Diagnostics Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Ulf Fini Jastrow
- FS-FLASH-D, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Andreas Koch
- X-ray Photon Diagnostics Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Joakim Laksman
- X-ray Photon Diagnostics Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Jia Liu
- X-ray Photon Diagnostics Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Marc Planas
- X-ray Photon Diagnostics Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Andrey A Sorokin
- FS-FLASH-D, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Kai Tiedtke
- FS-FLASH-D, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Jan Grünert
- X-ray Photon Diagnostics Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
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