Dissertationen zum Thema „European X-Ray Free Electron Laser“
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Heuer, Michael [Verfasser], und Gerwald [Akademischer Betreuer] Lichtenberg. „Identification and control of the laser-based synchronization system for the European X-ray Free Electron Laser / Michael Heuer ; Betreuer: Gerwald Lichtenberg“. Hamburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2018. http://d-nb.info/1162952954/34.
Der volle Inhalt der QuelleGeßler, Patrick [Verfasser], und Klaus [Akademischer Betreuer] Schünemann. „Synchronization and sequencing of data acquisition and control electronics at the European X-ray free electron laser / Patrick Geßler. Betreuer: Klaus Schünemann“. Hamburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2015. http://d-nb.info/1079905502/34.
Der volle Inhalt der QuelleGeßler, Patrick Verfasser], und Klaus [Akademischer Betreuer] [Schünemann. „Synchronization and sequencing of data acquisition and control electronics at the European X-ray free electron laser / Patrick Geßler. Betreuer: Klaus Schünemann“. Hamburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2015. http://d-nb.info/1079905502/34.
Der volle Inhalt der QuellePiccinardi, Rita. „X-Ray Free-Electron Lasers“. Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10286/.
Der volle Inhalt der QuelleGorman, Martin Gerard. „X-ray diffraction studies of shock compressed bismuth using X-ray free electron lasers“. Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/25865.
Der volle Inhalt der QuelleNilsson, Daniel. „Zone Plates for Hard X-Ray Free-Electron Lasers“. Doctoral thesis, KTH, Biomedicinsk fysik och röntgenfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-122161.
Der volle Inhalt der QuelleQC 20130514
Jaisle, Nicolas. „Contraindre la fusion partielle dans les intérieurs planétaires en combinant les approches numériques et expérimentales“. Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALU013.
Der volle Inhalt der QuelleThe study of partial melting processes in planetary interiors is of prime importance to understand planetary evolution mechanisms. This is even more true when considering the increasing number of exoplanetary discoveries which likely acknowledged a high variety of histories. A main experimental tool for to study deep planetary interior conditions is the diamond anvil cell (DAC), allowing to raise pressures on micron-sized samples up to hundreds of GPa and at temperatures up to thousands of Kelvins. The study of sample’s physical properties such as their phase change pressures and temperatures (P,T) can be analyzed in X-ray generating synchrotron facilities, using the X-ray diffraction (XRD) properties of minerals. Those experiments may yet suffer from the continuous laser heating technique which generates strong temperature gradients within the samples and may lead to chemical migration in the heated zone. The sample in-situ analysis is then achieved on a composition diverging from the initial one which does not necessarily correspond to what was intended to be measured. This thesis suggests a new experimental approach consisting in using a short and intense (250 ns) laser heating pulse in order to limit that chemical migration. This experimental setup was tested on iron alloys of the Fe-Si-O ternary system, results on such compositions being for instance applicable on in the context of Earth’s liquid outer core crystallization. Our experiments are run at the European X-ray Free Electron Laser (EuXFEL) facility which generates a high brilliance pulsed X-ray source (series of 30 fs pulses at frequencies up to 4.5 MHz (one pulse each 221.5 ns). Combined to the µs fraction laser heating, the EuXFEL experiments allow to obtain a temporal resolution of the sample evolution during its cooling, allowing to observe crystallization sequences. A streak optical pyrometry (SOP) surface temperature measurement is achieved simultaneously to the XRD with time resolution below the µs-scale. However, measurements achieved at the EuXFEL do not allow to fully resolve the extent of the phenomena occurring during experiments. To compensate this lack of information, we developed a numerical model based on the finite element method (FEM) to reproduce the achieved experiments. This model uses the material properties (such as ρ, K, G, κ, Cp and latent heat) at the experimental pressure and temperature conditions including their P,T dependencies when available. Equations of state (EoS) related variations where included in the model for the related parameters. To reproduce the experiments, the model values are adjusted by minimizing the mean error compared to the SOP data. Combining experimental XRD with best-fitting model temperatures, it is possible to get back to the P, T conditions during the samples phase change. In addition, the FEM furnishes temperature and pressure maps highlighting e.g. sample internal gradients and allowing to evaluate the degree of homogeneity of P and T, both assumed to be critical parameter in chemical migration. Models allow as well to calculate the constraint distribution in the DAC assemblage which can be an important factor in certain conditions. Finally, experiments directly using X-rays to heat the sample were achieved, analyzed and reproduced by modelling. Using the models, the possibility of deducing material properties such as thermal conductivity from best fits to experimental data are explored
Angal-Kalinin, Deepa. „Beam dynamics in spreaders for future X-ray free electron laser facilities“. Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3007693/.
Der volle Inhalt der QuelleÖstlin, Christofer. „Single-molecule X-ray free-electron laser imaging : Interconnecting sample orientation with explosion data“. Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-231009.
Der volle Inhalt der QuelleSeiboth, Frank [Verfasser], und Christian G. [Akademischer Betreuer] Schroer. „Refractive Hard X-Ray Nanofocusing at Storage Ring and X-Ray Free-Electron Laser Sources / Frank Seiboth. Betreuer: Christian G. Schroer“. Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://d-nb.info/1103233300/34.
Der volle Inhalt der QuelleKassemeyer, Stephan [Verfasser]. „Ultrafast coherent diffractive imaging of nanoparticles using X-ray free-electron laser radiation / Stephan Kassemeyer“. Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1053653689/34.
Der volle Inhalt der QuelleRoedig, Christoph Antony. „Application of Strong Field Physics Techniques to Free Electron Laser Science“. The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338264394.
Der volle Inhalt der QuelleRackstraw, David Simon. „Opacity and saturable absorption in solid-density plasmas generated by an X-ray free-electron-laser“. Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:38596abc-a7ad-4a2a-ba58-50e8f3df2bc6.
Der volle Inhalt der QuellePreston, Thomas Robert. „Measurements of the K-shell opacity in solid-density plasmas heated by an X-ray Free Electron Laser“. Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:1983895a-b336-45e9-a5d0-b6badc8efb47.
Der volle Inhalt der QuelleBergh, Magnus. „Interaction of Ultrashort X-ray Pulses with Material“. Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8274.
Der volle Inhalt der QuelleSellberg, Jonas A. „X-ray scattering and spectroscopy of supercooled water and ice“. Doctoral thesis, Stockholms universitet, Fysikum, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-103009.
Der volle Inhalt der QuelleAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript. Paper 6: Manuscript.
Ciricosta, Orlando. „Plasma evolution and continuum lowering in hot dense matter generated by X-ray free electron lasers“. Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2f872e7c-80dd-43d5-b171-b1d14957c0e6.
Der volle Inhalt der QuelleBrand, André [Verfasser], und Vollrath Martin [Akademischer Betreuer] Axt. „Coherent ionization dynamics induced by intense X-ray free-electron laser pulses / André Brand. Betreuer: Vollrath Martin Axt“. Bayreuth : Universität Bayreuth, 2016. http://d-nb.info/1082289167/34.
Der volle Inhalt der QuelleRudek, Benedikt [Verfasser], und Joachim [Akademischer Betreuer] Ullrich. „Multiple Ionization of Heavy Atoms by Intense X-Ray Free-Electron Laser Pulses / Benedikt Rudek ; Betreuer: Joachim Ullrich“. Heidelberg : Universitätsbibliothek Heidelberg, 2012. http://d-nb.info/1179784510/34.
Der volle Inhalt der QuelleWeinbaum, Michael. „A Novel Approach to X-ray Mirror Bending Stability and Control“. Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3700.
Der volle Inhalt der QuelleGrguraš, Ivanka [Verfasser], und Adrian L. [Akademischer Betreuer] Cavalieri. „Time resolved photoelectron spectroscopy for femtosecond characterization of X-ray free-electron laser pulses / Ivanka Grguraš ; Betreuer: Adrian L. Cavalieri“. Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://d-nb.info/1117798089/34.
Der volle Inhalt der QuelleGrguraš, Ivanka Verfasser], und Adrian L. [Akademischer Betreuer] [Cavalieri. „Time resolved photoelectron spectroscopy for femtosecond characterization of X-ray free-electron laser pulses / Ivanka Grguraš ; Betreuer: Adrian L. Cavalieri“. Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://d-nb.info/1117798089/34.
Der volle Inhalt der QuelleHäger, Wille. „Characterization of fading effects of a MOSFET semiconductor dosimeter to be used on an X-ray laser“. Thesis, Stockholms universitet, Medicinsk strålningsfysik (tills m KI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-147485.
Der volle Inhalt der QuelleSteiniger, Klaus. „High-Yield Optical Undulators Scalable to Optical Free-Electron Laser Operation by Traveling-Wave Thomson-Scattering“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-234847.
Der volle Inhalt der QuelleInkohärente und kohärente Lichtquellen werden in allen Feldern der physikalischen Forschung intensiv eingesetzt. Im Besonderen ermöglichen hoch-brilliante Röntgenquellen, wie Synchrotrone der dritten Generation und Freie-Elektronen Laser, einzigartige Experimentiertechniken wodurch diese zu unverzichtbaren Werkzeugen wurden. Sie sind allerdings auch im Umfang zu Großforschungseinrichtungen herangewachsen. Um den hohen Bedarf an hoch-brillianten Lichtquellen zu decken, besteht daher die Notwendigkeit neuartige und kompakte Quellen zu entwickeln welche auf dem Maßstab eines Labors realisierbar sind. Diese Dissertation widmet sich der Traveling-Wave Thomsonstreuung (TWTS) welche die Realisierung ultra-kompakter, intrinsisch synchronisierbarer und hoch-brillianter Röntgenquellen ermöglicht. TWTS ist eine Methode der Streuung von Laserpulsen an relativistischen Elektronen. Dabei durchquert ein Elektronenpuls mit nahezu Lichtgeschwindigkeit einen Laserpuls. Während der Durchquerung beginnen die Elektronen im Feld des Laserpulses zu oszillieren wobei sie Strahlung emittieren. Die ausgesandte Strahlung besitzt eine deutlich kürzere Wellenlänge als das Laserfeld aufgrund der hohen Elektronengeschwindigkeit und der damit verbundenen großen Dopplerverschiebung. Das besondere an TWTS ist, dass Elektronen- und Laserpropagationsrichtung einen Winkel einschließen sowie pulsfrontverkippte Hochleistungslaserpulse eingesetzt werden. Dadurch können um Größenordnungen längere Interaktionsdistanzen als in herkömmlichen frontalen Thomsonstreuungsanordnungen erreicht werden. TWTS ermöglicht dadurch die Realisierung optischer Freie-Elektronen Laser (OFEL) und inkohärenter Strahlungsquellen mit einer um Größenordnungen erhöhten Photonenausbeute gegenüber Thomsonstreuungsquellen in frontalen Interaktionsanordungen. Werden modernste Elektronenbeschleuniger und Lasersysteme genutzt, dann ist der Betrieb optischer Freie-Elektronen Laser bereits heute mit TWTS möglich. Das wird in der Dissertation am Beispiel eines Vakuumultraviolettstrahlung emittierenden TWTS OFEL gezeigt. Dessen Anforderungen an die Qualität der Elektronen- und Laserpulse werden im Detail in der Arbeit besprochen sowie weitere Beispiele weicher und harter Röntgenstrahlung emittierender TWTS OFEL präsentiert. Diese Anforderungen werden anhand von Skalierungsvorschriften ermittelt welche aus einer selbstkonsistenten, 1.5 dimensionalen Theorie zur Wechselwirkung zwischen Elektronen und Laserfeld in TWTS abgeleitet sind. Sowohl die Theorie zur Wechselwirkung als auch die Ableitung der Skalierungsvorschriften sind Teile dieser Dissertation. Eine wichtige Erkenntnis der Theorie ist die qualitative Äquivalenz von Elektronen- und Strahlungsfeldbewegungsgleichungen in TWTS zu denen herkömmlicher Freie-Elektronen Laser. Das beweist analytisch die Möglichkeit zur Realisierung eines OFEL mit TWTS. Einen weiteren wichtigen Teil dieser Dissertation bildet die Arbeit zur Generierung der Laserpulse mit verkippter Pulsfront. Optische Aufbauten zur Verkippung der Laserpulsfront werden vorgestellt und für einige der präsentierten TWTS OFEL ausführlich dargelegt. Die Aufbauten verkippen nicht nur die Laserpulsfront sondern gewähren gleichzeitig Kontrolle über die Laserpulsdispersionen. Dadurch kann während der gesamten Interaktionen eine ausreichend hohe Qualität des Laserfeldes sichergestellt werden, was für TWTS OFEL und inkohärente TWTS Lichtquellen mit großem Interaktionswinkel unbedingt notwendig ist. Ein Beispiel einer inkohärenten TWTS Lichtquelle wird ebenfalls präsentiert. Diese emittiert Strahlung mit einer um Größenordnungen höheren spektrale Photonendichte als eine herkömmliche Thomsonquelle in einer frontalen Streuanordnung mit vergleichbaren Laser- und Elektronenpulsen
Nakane, Takanori. „Data processing pipeline for serial femtosecond crystallography at SACLA“. Kyoto University, 2017. http://hdl.handle.net/2433/217997.
Der volle Inhalt der QuelleBalducci, Lodovico. „Dynamics of hemeproteins by femtosecond X-ray techniques“. Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S115.
Der volle Inhalt der QuelleRecently, the development of time resolved X-ray techniques has added the time dimension to structural biology studies, and have proven to be great tools to track proteins during the course of a reaction, or a specific conformational change. In particular the 4th generation X-ray sources (so called X-ray Free-Electron Lasers), with femtosecond pulses and extremely high fluences, are capable of probing ensembles of molecules essentially frozen in time under physiological conditions. After an overview of the past studies in the field, a basic introduction of the used techniques, the description of the experimental set-up and the flow of data reduction are presented. The last two chapters are devoted to present the results obtained during two separate sets of experiments, conducted at the XPP beamline of the Linac Coherent Light Source (SLAC, Menlo Park, CA, USA), to study the protein's structural changes, upon prototypical photo-dissociation reaction of carbon monoxide from heme proteins. During the first experiment, the global structural modification of three heme proteins has been probed by means of time resolved scattering technique, in order to observe eventual differences in the so called “protein-quake” depending on the protein's structure. In the second experiment, the active site of myoglobin was probed, during the same reaction, by X-ray absorption. The time resolved XANES spectra have been compared with theoretical calculations, in the framework of the multiple scattering theory, in order to retrieve a detailed picture of the ultra-fast dynamics. A further small side-project dealt with the precise measurement of static scattering patterns of carboxy hemoglobin with the goal of defining its multiple equilibrium structures by comparison with linear combinations of known crystallographic structures. In conclusion, in this Ph.D. thesis we tried to add some small pieces in the understanding of ultra-fast proteins dynamics by applying both standard (Guinier) and almost unexplored (multiple scattering calculations on time resolved data) analysis methods: depending on the system and the level of details required, these methodologies, here applied on model systems, can be considered excellent tools for further research on more complicated proteins
Chen, Joe. „Image Reconstruction in Serial Femtosecond Nanocrystallography“. Thesis, University of Canterbury. Electrical and Computer Engineering, 2015. http://hdl.handle.net/10092/10661.
Der volle Inhalt der QuelleSchorb, Sebastian [Verfasser], und Thomas [Akademischer Betreuer] Möller. „Size-dependent ultrafast ionization dynamics of nanoscale samples in intense femtosecond x-ray free-electron laser pulses / Sebastian Schorb. Betreuer: Thomas Möller“. Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2012. http://d-nb.info/1027798306/34.
Der volle Inhalt der QuelleErk, Benjamin Michael Dieter [Verfasser], und Joachim [Akademischer Betreuer] Ullrich. „Fragmentation Dynamics of Small Molecules upon Multiple Ionization by X-Ray Free-Electron Laser Pulses / Benjamin Michael Dieter Erk ; Betreuer: Joachim Ullrich“. Heidelberg : Universitätsbibliothek Heidelberg, 2013. http://d-nb.info/1177148048/34.
Der volle Inhalt der QuelleCamacho, Garibay Abraham. „Dynamics of Highly Charged Finite Systems Induced by Intense X-ray Pulses“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-212203.
Der volle Inhalt der QuelleFERRARI, EUGENIO. „Advances in Seeded Free Electron Lasers: Generation and Control of Stable and Fully Coherent X-Ray Pulses in Conventional and Exotic Configurations“. Doctoral thesis, Università degli Studi di Trieste, 2016. http://hdl.handle.net/11368/2908075.
Der volle Inhalt der QuelleVinko, Sam M. „Creation and study of matter in extreme conditions by high-intensity free-electron laser radiation“. Thesis, University of Oxford, 2011. https://ora.ox.ac.uk/objects/uuid:dccfa977-ebe9-4f1b-ab9d-270684fcbfca.
Der volle Inhalt der QuelleHantke, Max Felix. „Coherent Diffractive Imaging with X-ray Lasers“. Doctoral thesis, Uppsala universitet, Molekylär biofysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-306609.
Der volle Inhalt der QuelleSchubert, Robin Verfasser], und Christian [Akademischer Betreuer] [Betzel. „Preparation and scoring of protein nano- and microcrystals for synchrotron and free-electron laser X-ray radiation sources / Robin Schubert ; Betreuer: Christian Betzel“. Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://nbn-resolving.de/urn:nbn:de:gbv:18-81761.
Der volle Inhalt der QuelleSchubert, Robin [Verfasser], und Christian [Akademischer Betreuer] Betzel. „Preparation and scoring of protein nano- and microcrystals for synchrotron and free-electron laser X-ray radiation sources / Robin Schubert ; Betreuer: Christian Betzel“. Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://d-nb.info/1120014999/34.
Der volle Inhalt der QuelleHiraki(Nishiyama), Toshiyuki. „Static structure and dynamical structural changes of nanoparticles using XFEL pulses“. Kyoto University, 2020. http://hdl.handle.net/2433/253074.
Der volle Inhalt der QuelleJönsson, Olof. „Ultrafast Structural and Electron Dynamics in Soft Matter Exposed to Intense X-ray Pulses“. Doctoral thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-331936.
Der volle Inhalt der QuelleSundman, Tobias. „Noise Reduction in Flash X-ray Imaging Using Deep Learning“. Thesis, Uppsala universitet, Avdelningen för beräkningsvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-355731.
Der volle Inhalt der QuelleEkeberg, Tomas. „Flash Diffractive Imaging in Three Dimensions“. Doctoral thesis, Uppsala universitet, Molekylär biofysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-179643.
Der volle Inhalt der QuelleHeider, Rupert Patrick [Verfasser], Reinhard [Akademischer Betreuer] Kienberger, Reinhard [Gutachter] Kienberger und Christian [Gutachter] Back. „Attosecond Metrology – Characterization of X-ray Free-electron Laser Pulses via Angular Streaking and Application of Attosecond Spectroscopy on Liquid H2O / Rupert Patrick Heider ; Gutachter: Reinhard Kienberger, Christian Back ; Betreuer: Reinhard Kienberger“. München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1168798590/34.
Der volle Inhalt der QuelleHeider, Rupert Patrick Verfasser], Reinhard [Akademischer Betreuer] [Kienberger, Reinhard [Gutachter] Kienberger und Christian [Gutachter] Back. „Attosecond Metrology – Characterization of X-ray Free-electron Laser Pulses via Angular Streaking and Application of Attosecond Spectroscopy on Liquid H2O / Rupert Patrick Heider ; Gutachter: Reinhard Kienberger, Christian Back ; Betreuer: Reinhard Kienberger“. München : Universitätsbibliothek der TU München, 2018. http://nbn-resolving.de/urn:nbn:de:bvb:91-diss-20180920-1442076-1-3.
Der volle Inhalt der QuelleWoodhouse, Joyce. „Etude d'une protéine fluorescente photo-commutable par cristallographie résolue en temps en utilisant les lasers à électrons libres“. Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY026/document.
Der volle Inhalt der QuelleReversibly switchable fluorescent proteins (RSFPs) are able to reversibly toggle between a fluorescent on-state and a non-fluorescent off-state under visible light irradiation. This property makes them a suitable marker used in super-resolution microscopy (or nanoscopy). The photo-switching mechanism involves isomerisation of the chromophore and a change of its protonation state. This mechanism has been well studied but remains poorly understood. The structural nature and the sequential order of atomistic events are still under debate. Some of them take place on the ultra-fast time scale and make structural investigation by X-ray crystallography impossible using current synchrotron radiation sources whose temporal resolution they offer is limited. X-ray free electron lasers (XFELs) are a new kind of X-ray source producing femtosecond pulses that allow structural investigation of ultra-fast intermediates during photoswitching. They are also so bright that crystallographic data collection from micro- and nanometer-sized crystals became possible. The bright and short XFEL pulses required a new methodology to be developed, the so-called serial crystallography methodology. This method is now being adapted to synchrotron radiation facilities.Here is presented a time-resolved crystallography study of the reversibly switchable green fluorescent protein 2 (rsEGFP2). A microcrystallization protocol is described allowing the preparation of suitable samples in large amounts for time-resolved serial crystallography experiments. A photoswitching mechanism of rsEGFP2 is proposed based on crystallographic results obtained from data collected at the two XFEL facilities currently fully operational, i.e. the LCLS in the USA and SACLA in Japan. In particular, the structure of two photoswitching intermediates have been determined, one featuring a twisted chromophore in the excited state and the other displaying a protonated cis isomer of the chromophore in the ground state. The structural characterization of rsEGFP2 variants by traditional oscillation crystallography combined with the serendipitous discovery of an alternate chromophore conformation in the off-state during an XFEL experiment provided unique insight into the photophysical behavior of the protein
Dacasa, Pereira Hugo. „Spatial and temporal metrology of coherent ultrashort pulses inthe extreme-ultraviolet domain“. Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX041/document.
Der volle Inhalt der QuelleUltrashort pulses of extreme-ultraviolet (XUV) radiation have a wide range of applications in fields such as plasma probing, spectroscopy, or the study of ultrafast dynamics in atoms and molecules.Nowadays, there are three main sources of such pulses. High-order harmonic generation (HHG) in rare gases or solid surfaces is able to provide attosecond pulses. However, their limited energy, of the order of nanojoules, limits its number of applications. The amplification of high-harmonic pulses in laser-driven plasmas (SXRL) has been demonstrated to provide energies of tens of microjules. Higher pulse energies can be obtained from seeded XUV free-electron lasers (FELs), large-scale facilities with more limited accessibility.In recent years, significant progress has been made with each of these sources towards the generation of shorter pulses. It is thus necessary to develop new techniques for full temporal metrology of ultrashort XUV pulses. Additionally, many experiments, such as those involving nonlinear phenomena, require high XUV intensities. Efficient focusing of low-energy pulses can significantly increase their range of application. Good wavefronts are required in order to focus XUV pulses to high intensities, and the optics must be of high quality and precisely aligned.In this thesis, the spatial properties of high-harmonic pulses are extensively explored thanks to the use of an XUV Hartmann wavefront sensor. This device is also proven here to be useful for tabletop, at-wavelength characterization and optimization of XUV optical systems with HHG sources.The problem of performing full temporal characterization of XUV pulses is also discussed in detail, and two new schemes for complete pulse reconstruction for seeded XUV FELs and seeded SXRLs are presented. Finally, the first implementation of chirped pulse amplification (CPA) in a seeded XUV FEL is reported, and its implementation in seeded SXRLs is discussed as well
Eliah, Dawod Ibrahim. „Structural integrity of highly ionized peptides“. Thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-387886.
Der volle Inhalt der QuelleDebus, Alexander. „Brilliant radiation sources by laser-plasma accelerators and optical undulators“. Forschungszentrum Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-91303.
Der volle Inhalt der QuelleBattistoni, Andrea. „Broad band acoustic spectroscopy in disordered systems“. Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/10942.
Der volle Inhalt der QuelleThe present work of thesis is situated within the framework of the study of disordered systems as liquids and glasses. A liquid is a system characterized by long range translational invariance and by a short range ordered structure. In the liquid state, contrarily to the crystalline one, there is not structural periodicity and all we learnt from solid state physics (Block’s theorem, phonons, Brillouin’s zones, eigen-states of plane waves, etc.) must be fully revised. The macroscopic collective properties of condensed matter are the result of inter and intra-molecular interactions that are typified by characteristic time and space scales. A longstanding and powerful tool to investigate the collective nature of the microscopic processes inside the system is the acoustic spectroscopy. While in the case of crystalline phase we could take advantage of the periodical structure of the system, limiting our investigation to the so called first Brillouin zone, in order to characterize a disordered system we need to explore a widest as possible spectral range to access the all time and space scales in which the dynamical phenomena occur. This approach can be called Broad Band Acoustic Spectroscopy . My PhD activity was devoted to the development of new experimental methods and techniques allowing the exploration with continuity of dynamics evolving with timescales from tenth’s of ns’s to ps’s. I could test such Broad Band Acoustic Spectroscopy on a prototypical sample: acetonitrile, the liquid with highest dipole moment, known for its many different inter- and intra-molecular dynamics. Using several experimental and computational approaches I could characterize the main dynamical processes for such compound in its whole liquid phase. Thanks to the crossing of the all acquired information, it was possible to identify a mutual influence between different relaxations whose behaviour otherwise was not possible to correctly understand. After a brief introduction to contextualize the Broad Band Acoustic Spectroscopy in disordered systems, in Chapter 1 is presented an overview of the experimental techniques used to perform the measurements within this work. In this chapter, the first my original contribution to the extension of acoustic spectral range finds the place. Thanks to the design and realization of particular spatial filters it is now possible to perform Brillouin Light Scattering experiments with angle tunabil- ity without incurring in annoying spurious contributions issues. In the chapter are also recalled the main physical principles at the ground of every presented tech- nique, in particular stressing the complementarity of the energy and time resolved spectroscopies. Because all the information from the inner dynamics of the sample are mediated by the acoustic modes interaction, Chapter 2 is dedicated to the formalism of the density fluctuations, highlighting the differences between the hydrodynamic model, valid at macroscopic length-scales, and the memory functions approach, necessary to describe the mesoscopic region where the characteristic length-scales of the acoustic modes are comparable to the inter-particles distances. In Chapter 3 are shown the experimental results obtained thanks to the Broad Band Spectroscopy in the whole temperature range of the liquid phase of acetoni- trile. We could first measure some thermodynamical quantities by a non linear spectroscopy named Transient Grating, shedding light on the literature debate on them. Among the obtained results, we appreciated a temperature dependency of the heat capacity ratio which is usually considered a constant. Starting from these results and using the filtering approach introduced in Chapter 1, we could profitably study the vibrational relaxation of acetonitrile discovering some relevant discrepan- cies with previous studies. In this way we demonstrated the importance to avoid eventual spurious contributions and to have complementary information from dif- ferent spectral domains. Then there will be shown the results for the so called structural relaxation, obtained in the high energy domain by Inelastic X-ray Scat- tering. A really interesting correlation has been found with the result obtained by the ultrafast response of the Transient Grating method. Once again, to obtain such comparison was necessary to combine the information arising from many different spectral ranges, fact that highlights the utility and endorses the multi-techniques broad band acoustic spectroscopy method. The temperature dependence of the aforementioned relaxation processes sug- gested to evaluate if any coupling there exist between the two. This is exactly what we were able to appreciate in the deep-UV domain and we proposed a phenomeno- logical model to give a picture of the occurring interaction. To further investigate such dynamics coupling effect, could be extremely useful to explore the soft-UV spectral range but so far any technique was able to access such energy domain. In Chapter 4 we thus present our innovative solution to the problem: a novel table top Fabry-Perot interferometer conceived to operate with UV laser source and with only reflecting optics. The last chapters of the thesis describe my contribution to the forthcoming Free Electron Laser (FEL) based experiment to further increase the accessible spectral range to the acoustic spectroscopy: the TIMER project. In particular I will show the result obtained with the pilot experiment named “mini-TIMER” in which we could demonstrate the feasibility of a Transient Grating experiment in the Extreme Ultra Violet (EUV) domain. When TIMER will be operative it will be the first experimental setup able to probe the EUV mesoscopic region of crucial importance for the study of glasses and nano-structures. This result paves the way to a new class of intriguing experiments only matter of theoretical considerations so far: the so called four wave mixing experiments with elemental selectivity.
Il presente lavoro di tesi si colloca nell’ambito dello studio dei sistemi disordi- nati quali liquidi e vetri. Un liquido ´e un sistema caratterizzato da invarianza traslazionale a lungo raggio e da una struttura ordinata a corto raggio. Lo stato liquido, a differenza di quello cristallino, non gode di una periodicit`a strutturale e tutto ci`o che avevamo imparato dalla fisica dello stato solido (teorema di Block, fononi, zone di Brillouin, autostati di onde piane, etc.) deve essere completamente rivisto. Le propriet`a collettive della materia sono il risultato di interazioni a livello inter- e intra-molecolare identificate da caratteristiche scale temporali e spaziali. Uno strumento ormai affermato e utile per lo studio della natura collettiva dei processi microscopici attivi all’interno del sistema ´e la spettroscopia acustica. Mentre nel caso della fase cristallina si poteva sfruttare la natura periodica della struttura del sistema, limitando lo studio alla cosiddetta prima zona di Brillouin, per caratteriz- zare un sistema disordinato ´e necessario esplorare un intervallo spettrale il pi`u ampio possibile cosí da poter aver accesso alle scale spazio-temporali in cui le dinamiche avvengo. Questo tipo di approccio pu`o essere chiamato Spettroscopia Acustica ad Ampia Banda Spettrale . Il mio dottorato ´e stato dedicato allo sviluppo di nuovi metodi e tecniche speri- mentali per esplorare con continuit`a i processi dinamici la cui evoluzione avviene su scale di tempi tra le decine di ns e i ps. Tale Spettroscopia Acustica ad Ampia Banda Spettrale ´e stata testata su un campione prototipo di acetonitrile, il liquido con il pi´u alto momento di dipolo esistente, noto per le sue molteplici dinamiche di orgine inter- e intra-molecolare. Usando diversi approcci sperimentali e computazionali ´e stato possibile caratterizzare i principali processi di rilassamento per tale composto in tutta la sua fase liquida. Combinando poi tutte le informazioni acquisite, ´e stato possibile indentificare una mutua influenza tra i diversi processi di rilassamento il cui comportamento altrimenti sarebbe rimasto incompreso. Dopo una breve introduzione per contestualizzare la Spettroscopia Acustica ad Ampia Banda Spettrale nell’ambito dei sistemi disordinati, nel Capitolo 1 viene offerta una panoramica delle tecniche sperimentali usate per effettuare le misure nel corso di questo lavoro. Trova posto in questo capitolo la descrizione del mio primo originale contributo all’estensione dell’intervallo spettrale acustico. Grazie alla progettazione e realizzazione di particolari filtri spaziali ´e ora possibile effet- tuare esperimenti di diffusione di luce Brillouin con angolo di scattering variabile senza dover incorrere in fastidiosi problemi di contributi spuri. Nel capitolo vengono anche richiamati i principali elementi di fisica alla base di ogni tecnica, marcando in particolare la caratteristica di complementariet`a tra esperimenti risolti in tempo e in energia. Siccome tutte le informazioni a proposito delle dinamiche interne del campione sono mediate dall’interazione coi modi acustici, il Capitolo 2´e dedicato al formalismo delle fluttuazioni di densit`a, evidenziando le differenze tra il modello idrodinamico, valido per scale spaziali macroscopiche, e l’approccio delle funzioni memoria, nec- essario per descrivere la regione mesoscopica dove le dimensioni caratteristiche dei modi acustici diventano confrontabili con le distanze tra le particelle. Nel Capitolo 3 sono riportati i risultati sperimentali ottenuti mediante la Spet- troscopia Acustica ad Ampio Intervallo Spettrale nell’intero range di temperature in cui l’acetonitrile permane allo stato liquido. Per prima cosa, attraverso un tecnica fotonica di spettroscopia non lineare (Transient Grating) ´e stato possibile misurare alcune variabili termodinamiche, potendo fare chiarezza tra i vari contributi presenti in letteratura. Tra i risultati ottenuti, la dipendenza in temperatura del rapporto tra i calori specifici laddove usualmente viene considerata costante. Partendo da questi risultati e usando l’approccio di filtraggio introdotto nel Capitolo 1, ´e stato possibile studiare il rilassamento vibrazionale dell’acetonitrile scoprendo alcune ril- evanti discrepanze con i precedenti lavori riportati in letteratura. Abbiamo cosí dimostrato l’importanza di eliminare eventuali contributi spuri e di poter attingere a informazioni complementari da diversi domini spettrali. Verr`a inoltre mostrato il risultato dello studio del cosiddetto rilassamento strutturale effettuato nel range di alte energie grazie allo Scattering di raggi X. Una interessante correlazione si ´e po- tuta riscontrare tra i risultati di questo esperimento e quelli ottenuti con la tecnica Transient Grating nella sua risposta ultraveloce. Ancora una volta, per ottenere tale risultato ´e stato necessario combinare informazioni provenienti da molti inter- valli spettrali diversi, confermando la validit`a di un approccio multi-tecnica come quello della spettroscopia acustica a larga banda spettrale. L’andamento in tem- peratura dei suddetti processi di rilassamento suggerivano di valutare la presenza di un eventuale accoppiamento tra i due fenomeni. ´E esattamente ci`o che abbiamo osservato esplorando il dominio del profondo ultravioletto e per il quale abbiamo proposto un modello fenomenologico in grado di fornire una rappresentazione delle interazioni in gioco. Per poter approfondire tale fenomeno di accoppiamento sarebbe estremamente utile poter esplorare l’intervallo spettrale degli UV soffici, ma fino ad oggi nessuna tecnica era in grado accedere a tale range. Nel Capitolo 4 mostriamo la nostra innovativa soluzione al problema: un nuovo interferometro Farby-Perot “table-top”, concepito per lavorare con una sorgente UV laser e con sole ottiche riflettive. Gli ultimi capitoli della tesi descrivono il mio contributo al prossimo esperi- mento avente come sorgente di luce un laser ad elettroni liberi: il progetto TIMER, destinato ad aumentare ulteriormente il range spettrale sperimentalmente acces- sibile con la spettroscopia acustica. In particolare, mostrer`o i risultati ottenuti nell’esperimentopilotachiamato“mini-TIMER”graziealqualedimostratolapossibilit`a di effettuare un esperimento Transient Grating anche nel range spettrale dell’estremo UV (EUV). Quando TIMER sar`a operativo sar`a il primo setup sperimentale in grado di sondare la regione mesoscopica nell’EUV, zona di cruciale importanza per lo studio dei vetri e delle nanostrutture. Questo risultato apre inoltre la strada ad una nuova classe di interessanti esperimenti ad oggi oggetto solo di considerazioni teoriche: i cosiddetti esperimenti di “four wave mixing” combinati con la selettivit`a elementale che la radiazione EUV pu`o fornire.
XXVI Ciclo
1985
Rander, Torbjörn. „Photoelectron Spectroscopy on Atoms, Molecules and Clusters : The Geometric and Electronic Structure Studied by Synchrotron Radiation and Lasers“. Doctoral thesis, Uppsala University, Department of Physics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8343.
Der volle Inhalt der QuelleAtoms, molecules and clusters all constitute building blocks of macroscopic matter. Therefore, understanding the electronic and geometrical properties of such systems is the key to understanding the properties of solid state objects.
In this thesis, some atomic, molecular and cluster systems (clusters of O2, CH3Br, Ar/O2, Ar/Xe and Ar/Kr; dimers of Na; Na and K atoms) have been investigated using synchrotron radiation, and in the two last instances, laser light. We have performed x-ray photoelectron spectroscopy (XPS) on all of these systems. We have also applied ultraviolet photoelectron spectroscopy (UPS), resonant Auger spectroscopy (RAS) and near-edge x-ray absorption spectroscopy (NEXAFS) to study many of the systems. Calculations using ab initio methods, namely density functional theory (DFT) and Møller-Plesset perturbation theory (MP), were employed for electronic structure calculations. The geometrical structure was studied using a combination of ab initio and molecular dynamics (MD) methods.
Results on the dissociation behavior of CH3Br and O2 molecules in clusters are presented. The dissociation of the Na2 molecule has been characterized and the molecular field splitting of the Na 2p level in the dimer has been measured. The molecular field splitting of the CH3Br 3d level has been measured and the structure of CH3Br clusters has been determined to be similar to the structure of the bulk solid. The diffusion behavior of O2, Kr and Xe on large Ar clusters, as a function of doping rate, has been investigated. The shake-down process has been observed from excited states of Na and K. Laser excited Na atoms have been shown to be magnetically aligned. The shake-down process was used to characterize the origin of various final states that can be observed in the spectrum of ground-state K.
„Reconstruction Methods In Free Electron Laser X-Ray Diffraction“. Doctoral diss., 2011. http://hdl.handle.net/2286/R.I.9372.
Der volle Inhalt der QuelleDissertation/Thesis
Ph.D. Physics 2011
„Time-Resolved Crystallography using X-ray Free-Electron Laser“. Doctoral diss., 2015. http://hdl.handle.net/2286/R.I.36383.
Der volle Inhalt der QuelleDissertation/Thesis
Doctoral Dissertation Chemistry 2015
„Bacteriophage PR772 X-Ray Free Electron Laser and Cryo-Electron Microscopy Studies“. Master's thesis, 2019. http://hdl.handle.net/2286/R.I.55695.
Der volle Inhalt der QuelleDissertation/Thesis
Masters Thesis Microbiology 2019