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Novel C_(sf)/SiBCN composites prepared by densifying C_(sf)/MA-SiBCN with the PIP process:Oxidation behavior and damage mechanism

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Journal of Advanced Ceramics 2024年第5期13卷 666-678页

作者： Wenhao Dou Daxin Li Bingzhu Wang Zhihua Yang Jun Chen Dechang Jia Ralf Riedel Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structural-Functional Integration Materials and Green Manufacturing technology Harbin Institute of TechnologyHarbin 150001China Chongqing Research Institute of HIt Chongqing 401135China Beijing Institute of Control Engineering Beijing 100094China Institut für Materialwissenschaft Technische Universität DarmstadtDarmstadt D-64287Germany School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

to improve the oxidation resistance of short carbon fiber(C_(sf))-reinforced mechanically alloyed SiBCN(MA-SiBCN)(C_(sf)/MA-SiBCN)composites,dense amorphous C_(sf)/SiBCN composites containing both MA-SiBCN and polymer-derived ceramics SiBCN(PDCs-SiBCN)were prepared by repeated polymer infiltration and pyrolysis(PIP)of layered C_(sf)/MA-SiBCN composites at 1100℃,and the oxidation behavior and damage mechanism of the as-prepared C_(sf)/SiBCN at 1300–1600℃ were compared and discussed with those of C_(sf)/*** C_(sf)/MA-SiBCN composites resist oxidation attack up to 1400℃ but fail at 1500℃ due to the collapse of the porous framework,while the PIP-densified C_(sf)/SiBCN composites are resistant to static air up to 1600℃.During oxidation,oxygen diffuses through preexisting pores and the pores left by oxidation of carbon fibers and pyrolytic carbon(PyC)to the interior of the *** to the oxidative coupling effect of the MA-SiBCN and PDCs-SiBCN matrices,a relatively continuous and dense oxide layer is formed on the sample surface,and the interfacial region between the oxide layer and the matrix of the as-prepared composite contains an amorphous glassy structure mainly consisting of Si and O and an incompletely oxidized but partially crystallized matrix,which is primarily responsible for improving the oxidation resistance.

关键词： mechanically alloyed SiBCN(MA-SiBCN) polymer-derived ceramics SiBCN(PDCs-SiBCN) short carbon fiber-reinforced SiBCN(C_(sf)/SiBCN)composites polymer infiltration and pyrolysis(PIP) oxidation damage mechanism

Experimental investigation on slip conditions during thread rolling with flat dies

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Friction 2024年第1期12卷 136-143页

作者： Stefan VOLZ Peter GROCHE Institute for Production Engineering and Forming Machines Technical University DarmstadtOtto-Berndt Straße 2Darmstadt 64287Germany

the process design of flat die rolling operations can be a tedious and costly process due to the challenges posed by small process *** this work,an effort is made to closely investigate and understand the process limits caused by excessive slippage of the *** measurements are carried out to capture the characteristics of excessive slippage and the influence of the stroke rate and the tribological system on this process *** differences in slippage were observed,depending on the tribological *** systems with polymer based lubricants showed excessive slippage at low stroke rates,systems using oil or no lubricant endured higher stroke rates before process limits were *** optical measurements revealed three major forms of slippage:successful rolling without slippage,failure due to excessive slippage at process start,and failure due to excessive slippage at around one workpiece rotation.

关键词： rolling incremental forming thread rolling slippage profile rolling

Collisionless shock acceleration of protons in a plasma slab produced in a gas jet by the collision of two laser-driven hydrodynamic shockwaves

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Matter and Radiation at Extremes 2024年第2期9卷 12-25页

作者： J.-R.Marquès L.Lancia P.Loiseau P.Forestier-Colleoni M.tarisien E.Atukpor V.Bagnoud C.Brabetz F.Consoli J.Domange F.Hannachi P.Nicolaï M.Salvadori B.Zielbauer LULI CNRSÉcole PolytechniqueCEASorbonne UniversitéInstitut Polytechnique de Paris91128 Palaiseau CedexFrance CEA DAMDIF91297 Arpajon CedexFrance universitéParis-Saclay CEALMCE91680 Bruyères-le-ChatelFrance CENBG CNRS-IN2P3Universitéde Bordeaux33175 Gradignan CedexFrance GSI Helmholtzzentrum für Schwerionenforschung GmbH Planckstraße 164291 DarmstadtGermany university of darmstadt Schloßgartenstr.764289 DarmstadtGermany ENEA Fusion and technologies for Nuclear Safety Department C.R.FrascatiVia Enrico Fermi 45FrascatiRomeItaly CELIA Universitéde Bordeaux–CNRS–CEA33405 TalenceFrance universitéParis-Saclay CEALIDYL91191 Gif-sur-YvetteFrance

We have recently proposed a new technique of plasma tailoring by laser-driven hydrodynamic shockwaves generated on both sides of a gas jet[Marquès et al.,*** 28,023103(2021)].In a continuation of this numerical work,we study experimentally the influence of the tailoring on proton acceleration driven by a high-intensity picosecond laser in three cases:without tailoring,by tailoring only the entrance side of the picosecond laser,and by tailoring both sides of the gas *** tailoring,the acceleration is transverse to the laser axis,with a low-energy exponential spectrum,produced by Coulomb *** the front side of the gas jet is tailored,a forward acceleration appears,which is significantly enhanced when both the front and back sides of the plasma are *** forward acceleration produces higher-energy protons,with a peaked spectrum,and is in good agreement with the mechanism of collisionless shock acceleration(CSA).the spatiotemporal evolution of the plasma profile is characterized by optical shadowgraphy of a probe *** refraction and absorption of this beam are simulated by post-processing 3D hydrodynamic simulations of the plasma *** with the experimental results allows estimation of the thickness and near-critical density of the plasma slab produced by tailoring both sides of the gas *** parameters are in good agreement with those required for CSA.

关键词： acceleration hydrodynamic collision

temperature and structure measurements of heavy-ion-heated diamond using in situ X-ray diagnostics

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Matter and Radiation at Extremes 2024年第4期9卷 80-89页

作者： J.Lutgert P.Hesselbach M.Schorner V.Bagnoud R.Belikov P.Drechsel B.Heuser O.SHumphries P.Katrik B.Lindqvist C.Qu R.Redmer D.Riley G.Schaumann S.Schumacher A.tauschwitz D.Varentsov K.Weyrich X.Yu B.Zielbauer Zs.Major P.Neumayer D.Kraus Institut fur Physik Universitat RostockAlbert-Einstein-Str.2318059 RostockGermany GSI Helmholtzzentrum fur Schwerionenforschung Planckstr.164291 DarmstadtGermany Institut für Angewandte Physik Goethe-Universität Frankfurt am MainMax-von-Laue-Str.160438 Frankfurt am MainGermany Institut fur Geowissenschaften Goethe-Universitat Frankfurt am MainAltenhoferallee 160438 Frankfurt am MainGermany Helmholtz-Zentrum Dresden-Rossendorf Bautzner Landstr.40001328 DresdenGermany European XFEL GmbH Holzkoppel 422869 SchenefeldGermany Centre for Plasma Physics School of Mathematics and PhysicsQueen’s University BelfastUniversity RoadBelfast BT71NNUnited Kingdom Institut für Kernphysik Technische Universität DarmstadtSchlossgartenstr.964289 DarmstadtGermany State Key Laboratory of Nuclear Physics and technology Institute of Heavy Ion PhysicsPeking UniversityBeijing 100871China Helmholtz Institut Jena Frobelstieg 307743 JenaGermany

We present in situ measurements of spectrally resolved X-ray scattering and X-ray diffraction from monocrystalline diamond samples heatedwith an intense pulse of heavy *** this way,we determine the samples’heating dynamics and their microscopic and macroscopic structuralintegrity over a timespan of several *** the ratio of elastic to inelastic scattering with state-of-the-art density functionaltheory molecular dynamics simulations allows the inference of average temperatures around 1300 K,in agreement with predictions fromstopping power *** simultaneous diffraction measurements show no hints of any volumetric graphitization of the material,butdo indicate the onset of fracture in the diamond *** experiments pave the way for future studies at the Facility for Antiproton andIon Research,where a substantially increased intensity of the heavy ion beam will be available.

关键词： heated intense structure

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质子磁荷半径:新疑难?

Science Bulletin 2024年第4期69卷 419-421页

作者：林勇辉 Hans-Werner Hammer Ulf-G.Meiûner Helmholtz Institut für Strahlen-und Kernphysik and Bethe Center for theoretical Physics Universität BonnBonn D-53115Germany technische universität darmstadt Department of PhysicsInstitut für KernphysikDarmstadt 64289Germany ExtreMe Matter Institute EMMI and Helmholtz Forschungsakademie Hessen für FAIR GSI Helmholtzzentrum für Schwerionenforschung GmbHDarmstadt 64291Germany Institute for Advanced Simulation and Institut für Kernphysik Forschungszentrum JülichJülich D-52425Germany tbilisi State university Tbilisi 0186Georgia

the electric radius,rE,and the magnetic radius,rM,of the proton are fundamental quantities of low-energy QCD,as they are a measure of the probe-dependent size of the proton.

关键词： radius quantities fundamental

Demonstrating grating-based phase-contrast imaging of laser-driven shock waves

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Matter and Radiation at Extremes 2024年第4期9卷 90-97页

作者： Leonard Wegert Stephan Schreiner Constantin Rauch Bruno Albertazzi Paulina Bleuel Eric Frojdh Michel Koenig Veronika Ludwig Artem SMartynenko Pascal Meyer Aldo Mozzanica Michael Müller Paul Neumayer Markus Schneider Angelos triantafyllidis Bernhard Zielbauer Gisela Anton thilo Michel Stefan Funk Plasma Physics Department GSI Helmholtzzentrum fur SchwerionenforschungPlanckstraBe 164291 DarmstadtGermany Erlangen Centre for Astroparticle Physics(ECAP) Friedrich-Alexander-Universität Erlangen-NurnbergNikolaus-Fiebiger-StraBe 291058 ErlangenGermany LULI-CNRS CEASorbonne UniversitésEcole PolytechniqueInstitut Polytechnique de ParisF-91120 Palaiseau CedexFrance Paul Scherrer Institut(Psi) Forschungsstrasse 1115232VilligenSwitzerland Karlsruhe Institute of technology Institute of Microstructure TechnologyHermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany

Single-shot X-ray phase-contrast imaging is used to take high-resolution images of laser-driven strong shock *** a two-grating talbot interferometer,we successfully acquire standard absorption,differential phase-contrast,and dark-field images of the shocked *** agreement is demonstrated between experimental data and the results of two-dimensional radiation hydrodynamics simulations of the laser-plasma *** main sources of image noise are identified through a thorough assessment of the interferometer’s *** acquired images demonstrate that grating-based phase-contrast imaging is a powerful diagnostic tool for high-energy-density *** addition,we make a novel attempt at using the dark-field image as a signal modality of talbot interferometry to identify the microstructure of a foam target.

关键词： interaction. shock phase

Inner-shell ionization cross sections of atoms by positron impact

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Communications in theoretical Physics 2024年第6期76卷 142-147页

作者： Yuan-Cheng Wang Jia Ma Li-Guang Jiao Stephan Fritzsche College of Physical Science and technology Shenyang Normal UniversityShenyang 110034China Helmholtz-Institut Jena D-07743 JenaGermany GSI Helmholtzzentrum für Schwerionenforschung GmbH D-64291 DarmstadtGermany College of Science Shenyang Aerospace UniversityShenyang 110136China College of Physics Jilin UniversityChangchun 130012China theoretisch-Physikalisches Institut Friedrich-Schiller-Universität Jena07743 JenaGermany

the relativistic binary-encounter-Bethe model with Wannier-type threshold law is employed to obtain the inner-shell ionization cross sections of multi-electron atoms(Ni,Cu,Y,Ag,Au,Yb,ta,and Pb)for positron impact energies from the thresholds up to 105ke *** is good agreement between the present calculations and the experimental *** constant in the acceleration term derived from the Wannier law is determined to be 0.2 and 0.5 for the K-and L-shells,respectively.

关键词： positron scattering ionization cross section binary-encounter-Bethe model

Optical probing of ultrafast laser-induced solid-to-overdense-plasma transitions

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Light(Science & Applications) 2024年第5期13卷 973-984页

作者： Yasmina Azamoum Georg Alexander Becker Sebastian Keppler Guillaume Duchateau Stefan Skupin Mickael Grech Fabrice Catoire Sebastian Hell Issa tamer Marco Hornung Marco Hellwing Alexander Kessler Franck Schorcht Malte Christoph Kaluza GSI Helmholtzzentrum für Schwerionenforschung Planckstr.164291 DarmstadtGermany. Helmholtz Institute Jena Fröbelstieg 307743 JenaGermany. Institute of Optics and Quantum Electronics Friedrich-SchillerUniversität JenaMax-Wien-Platz 107743 JenaGermany. CEA-CEStA 15 Avenue des SablièresCS6000133116 Le BarpCedexFrance Institut Lumière Matière UMR 5306-CNRSUniversitéde Lyon 169622 VilleurbanneFrance. LULI CNRSCEASorbonne UniversitéInstitut Polytechnique de ParisPalaiseauFrance. universitéde Bordeaux-CNRS-CEA CELIAUMR 5107 TalenceFrance

Understanding the solid target dynamics resulting from the interaction with an ultrashort laser pulse is a challenging fundamental multi-physics problem involving atomic and solid-state physics,plasma physics,and laser *** of the initial interplay of the underlying processes is essential to many applications ranging from lowpower laser regimes like laser-induced ablation to high-power laser regimes like laser-driven ion *** the properties of the so-called pre-plasma formed as the laser pulse’s rising edge ionizes the target is complicated from the theoretical and experimental point of view,and many aspects of this laser-induced transition from solid to overdense plasma over picosecond timescales are still open *** the one hand,laser-driven ion acceleration requires precise control of the pre-plasma because the efficiency of the acceleration process crucially depends on the target properties at the arrival of the relativistic intensity peak of the *** the other hand,efficient laser ablation requires,for example,preventing the so-called“plasma shielding”.By capturing the dynamics of the initial stage of the interaction,we report on a detailed visualization of the pre-plasma formation and ***-thin diamond-like carbon foils are shown to transition from solid to plasma during the laser rising edge with intensitiest near-infrared probe transmission measurements evidence sub-picosecond dynamics of an expanding plasma with densities above 10^(23)cm^(−3)(about 100 times the critical plasma density).the complementarity of a solid-state interaction model and kinetic plasma description provides deep insight into the interplay of initial ionization,collisions,and expansion.

关键词： laser acceleration solid

Ultra-compact post-compressor on-shot wavefront measurement for beam correction at PHELIX

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High Power Laser Science and Engineering 2022年第3期10卷 2-10页

作者： J.B.Ohland U.Eisenbarth B.Zielbauer Y.Zobus D.Posor J.Hornung D.Reemts V.Bagnoud GSI Helmholtzzentrum für Schwerionenforschung 64291DarmstadtGermany Institute for Applied Physics Technische Universität Darmstadt64289 DarmstadtGermany Institute of Nuclear Physics Technische Universität Darmstadt64289 DarmstadtGermany Helmholtz-Institut Jena 07743 JenaGermany

In order to reach the highest intensities,modern laser systems use adaptive optics to control their beam ***,the focal spot is optimized after the compression stage of the system in order to avoid spatio-temporal *** also requires a wavefront sensor after the compressor,which should be able to measure the wavefront *** PHELIX,we have developed an ultra-compact post-compressor beam diagnostic due to strict space constraints,measuring the wavefront over the full aperture of 28 *** system features all-reflective imaging beam transport and a high dynamic range in order to measure the wavefront in alignment mode as well as on shot.

关键词： adaptive optics beam quality high intensity laser diagnostics on shot Strehl wavefront