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High Power Laser Science and Engineering 2024年第1期12卷 116-116页

作者： j.Goodman M.King E.j.Dolier r.Wilson r.j.gray P.McKenna 不详

Due to an isolated error in the 3D simulation parameters,the laser energy and intensity(calculated using the energy)values were incorrectly stated as 10.9 j and 3×10^(22) W cm^(−2),respectively,in Sections 3.3,7 and *** correct values are 39.8 j and 1.1×10^(23) W cm^(−2).Similarly,the values stated for the higher energy case,109 j and 3×10^(23) W cm^(−2) in Section 7,should be 398 j and 1.1×10^(24) W cm^(−2),respectively.

关键词： Bayesian optimization gamma rays laser-solid interactions machine learning radiation reaction

Optimization and control of synchrotron emission in ultraintense laser–solid interactions using machine learning

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高功率激光科学与工程:英文版 2023年第3期11卷 15-31页

作者： j.Goodman M.King E.j.Dolier r.Wilson r.j.gray P.McKenna SUPA Department of Physics University of StrathclydeGlasgowUK The Cockcroft Institute Sci-Tech DaresburyWarringtonUK

The optimum parameters for the generation of synchrotron radiation in ultraintense laser pulse interactions with planar foils are investigated with the application of Bayesian optimization,via Gaussian process regression,to 2D particle-incell *** properties of the synchrotron emission,such as the yield,are maximized,and simultaneous mitigation of bremsstrahlung emission is achieved with multi-variate objective *** angle-of-incidence of the laser pulse onto the target is shown to strongly influence the synchrotron yield and angular profile,with oblique incidence producing the optimal *** is further explored in 3D simulations,in which additional control of the spatial profile of synchrotron emission is demonstrated by varying the polarization of the laser *** results demonstrate the utility of applying a machine learning-based optimization approach and provide new insights into the physics of radiation generation in laser-foil interactions,which will inform the design of experiments in the quantum electrodynamics(QED)-plasma regime.

关键词： Bayesian optimization gamma rays laser-solid interactions machine learning radiation reaction

High order modes of intense second harmonic light produced from a plasma aperture

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Matter and radiation at Extremes 2022年第5期7卷 7-16页

作者： E.F.j.Bacon M.King r.Wilson T.P.Frazer r.j.gray P.McKenna SUPA Department of Physics University of StrathclydeGlasgow G40NGUnited Kingdom The Cockcroft Institute Sci-Tech DaresburyWarrington WA44ADUnited Kingdom

Because of their ability to sustain extremely high-amplitude electromagnetic fields and transient density and field profiles,plasma optical components are being developed to amplify,compress,and condition high-power laser *** recently demonstrated the potential to use a relativistic plasma aperture—produced during the interaction of a high-power laser pulse with an ultrathin foil target—to tailor the spatiotemporal properties of the intense fundamental and second-harmonic light generated[Duff et al.,***.10,105(2020)].Herein,we explore numerically the interaction of an intense laser pulse with a preformed aperture target to generate second-harmonic laser light with higher-order spatial *** maximum generation efficiency is found for an aperture diameter close to the full width at half maximum of the laser focus and for a micrometer-scale target *** spatial mode generated is shown to depend strongly on the polarization of the drive laser pulse,which enables changing between a linearly polarized TEM01 mode and a circularly polarized Laguerre–Gaussian LG01 *** demonstrates the use of a plasma aperture to generate intense higher-frequency light with selectable spatial mode structure.

关键词： polarization intense harmonic

Effects of target pre-heating and expansion on terahertz radiation production from intense laser-solid interactions

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High Power Laser Science and Engineering 2014年第1期2卷 13-17页

作者： X.H.Yuan Y.Fang D.C.Carroll D.A.MacLellan F.Du N.Booth M.Burza M.Chen r.j.gray Y.F.jin Y.T.Li Y.Liu D.Neely H.Powell G.Scott C.-G.Wahlstrm j.Zhang P.McKenna Z.M.Sheng Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy Shanghai Jiao Tong University Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences SUPA Department of Physics University of Strathclyde Central Laser Facility Rutherford Appleton Laboratory Department of Physics Lund University

The first experimental measurements of intense(～7 × 1019 W cm-2) laser-driven terahertz(THz) radiation from a solid target which is preheated by an intense pulse of laser-accelerated protons is reported. The total energy of the THz radiation is found to decrease by approximately a factor of 2 compared to a cold target reference. This is attributed to an increase in the scale length of the preformed plasma, driven by proton heating, at the front surface of the target,where the THz radiation is generated. The results show the importance of controlling the preplasma scale length for THz production.

关键词： target heating terahertz radiation

reflection of intense laser light from microstructured targets as a potential diagnostic of laser focus and plasma temperature

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High Power Laser Science and Engineering 2019年第1期7卷 10-16页

作者： j.jarrett M.King r.j.gray N.Neumann L.Dhl C.D.Baird T.Ebert M.Hesse A.Tebartz D.r.rusby N.C.Woolsey D.Neely M.roth P.McKenna Department of Physics SUPA University of Strathclyde Institut f¨ur Kernphysik Technische Universit?t Darmstadt York Plasma Institute University of York STFC-rutherford Appleton Laboratory Institut fur Kernphysik Technische Universit?t Darmstadt

The spatial-intensity profile of light reflected during the interaction of an intense laser pulse with a microstructured target is investigated experimentally and the potential to apply this as a diagnostic of the interaction physics is explored numerically. Diffraction and speckle patterns are measured in the specularly reflected light in the cases of targets with regular groove and needle-like structures, respectively, highlighting the potential to use this as a diagnostic of the evolving plasma surface. It is shown, via ray-tracing and numerical modelling, that for a laser focal spot diameter smaller than the periodicity of the target structure, the reflected light patterns can potentially be used to diagnose the degree of plasma expansion, and by extension the local plasma temperature, at the focus of the intense laser light. The reflected patterns could also be used to diagnose the size of the laser focal spot during a high-intensity interaction when using a regular structure with known spacing.

关键词： high power laser laser-solid interactions plasma temperature diagnosis

role of magnetic field evolution on filamentary structure formation in intense laser–foil interactions

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High Power Laser Science and Engineering 2019年第1期7卷 99-106页

作者： M.King N.M.H.Butler r.Wilson r.Capdessus r.j.gray H.W.Powell r.j.Dance H.Padda B.Gonzalez-Izquierdo D.r.rusby N.P.Dover G.S.Hicks O.C.Ettlinger C.Scullion D.C.Carroll Z.Najmudin M.Borghesi D.Neely P.McKenna SUPA Department of Physics University of Strathclyde Central Laser Facility STFC Rutherford Appleton Laboratory The john Adams Institute for Accelerator Science Blackett Laboratory Imperial College London Centre for Plasma Physics Queen's University Belfast

Filamentary structures can form within the beam of protons accelerated during the interaction of an intense laser pulse with an ultrathin foil target. Such behaviour is shown to be dependent upon the formation time of quasi-static magnetic field structures throughout the target volume and the extent of the rear surface proton expansion over the same *** is observed via both numerical and experimental investigations. By controlling the intensity profile of the laser drive,via the use of two temporally separated pulses, both the initial rear surface proton expansion and magnetic field formation time can be varied, resulting in modification to the degree of filamentary structure present within the laser-driven proton beam.

关键词： laser-plasma ion acceleration instabilities

Automated control and optimization of laser-driven ion acceleration

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高功率激光科学与工程:英文版 2023年第3期11卷 32-40页

作者： B.Loughran M.j.V.Streeter H.Ahmed S.Astbury M.Balcazar M.Borghesi N.Bourgeois C.B.Curry S.j.D.Dann S.DiIorio N.P.Dover T.Dzelzainis O.C.Ettlinger M.Gauthier L.Giuffrida G.D.Glenn S.H.Glenzer j.S.Green r.j.gray G.S.Hicks C.Hyland V.Istokskaia M.King D.Margarone O.McCusker P.McKenna Z.Najmudin C.Parisuaña P.Parsons C.Spindloe D.r.Symes A.G.r.Thomas F.Treffert N.Xu C.A.j.Palmer School of Mathematics and Physics Queen’s University BelfastBelfastUK Central Laser Facility STFC Rutherford Appleton LaboratoryDidcotUK Gérard Mourou Center for Ultrafast Optical Science University of MichiganAnn ArborMIUSA SLAC National Accelerator Laboratory Menlo ParkCAUSA Department of Electrical and Computer Engineering University of AlbertaEdmontonABCanada The john Adams Institute for Accelerator Science Imperial College LondonLondonUK ELI Beamlines Centre Institute of PhysicsCzech Academy of SciencesDolníBˇrežanyCzech Republic Department of Applied Physics Stanford UniversityStanfordCAUSA Department of Physics SUPAUniversity of StrathclydeGlasgowUK Faculty of Nuclear Sciences and Physical Engineering Czech Technical University in PraguePragueCzech Republic Department of Mechanical Engineering Stanford UniversityStanfordCAUSA Institut für Kernphysik Technische Universität DarmstadtDarmstadtGermany

The interaction of relativistically intense lasers with opaque targets represents a highly non-linear,multi-dimensional parameter *** limits the utility of sequential 1D scanning of experimental parameters for the optimization of secondary radiation,although to-date this has been the accepted methodology due to low data acquisition *** repetition-rate(Hrr)lasers augmented by machine learning present a valuable opportunity for efficient source ***,an automated,Hrr-compatible system produced high-fidelity parameter scans,revealing the influence of laser intensity on target pre-heating and proton generation.A closed-loop Bayesian optimization of maximum proton energy,through control of the laser wavefront and target position,produced proton beams with equivalent maximum energy to manually optimized laser pulses but using only 60%of the laser *** demonstration of automated optimization of laser-driven proton beams is a crucial step towards deeper physical insight and the construction of future radiation sources.

关键词： Bayesian optimization high repetition-rate laser-target interaction laser-driven particle acceleration proton generation

Versatile tape-drive target for high-repetition-rate laser-driven proton acceleration

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High Power Laser Science and Engineering 2023年第4期11卷 59-69页

作者： N.Xu M.j.V.Streeter O.C.Ettlinger H.Ahmed S.Astbury M.Borghesi N.Bourgeois C.B.Curry S.j.D.Dann N.P.Dover T.Dzelzainis V.Istokskaia M.Gauthier L.Giuffrida G.D.Glenn S.H.Glenzer r.j.gray j.S.Green G.S.Hicks C.Hyland M.King B.Loughran D.Margarone O.McCusker P.McKenna C.Parisuaña P.Parsons C.Spindloe D.r.Symes F.Treffert C.A.j.Palmer Z.Najmudin john Adams Institute for Accelerator Science Blackett LaboratoryImperial College LondonLondonUK School of Maths and Physics Queen’s University BelfastBelfastUK Central Laser Facility STFC Rutherford Appleton LaboratoryDidcotUK SLAC National Accelerator Laboratory Menlo ParkUSA ELI Beamlines Centre Institute of PhysicsCASDolni BrezanyCzech Republic Faculty of Nuclear Sciences and Physical Engineering Czech Technical University in PraguePragueCzech Republic Department of Physics SUPAUniversity of StrathclydeGlasgowUK Department of Mechanical Engineering Stanford UniversityStanfordUSA Department of Applied Physics Stanford UniversityStanfordUSA Department of Electrical and Computer Engineering University of AlbertaEdmontonCanada Institut für Kernphysik Technische Universität DarmstadtDarmstadtGermany

We present the development and characterization of a high-stability,multi-material,multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 *** tape surface position was measured to be stable on the sub-micrometre scale,compatible with the high-numerical aperture focusing geometries required to achieve relativistic intensity interactions with the pulse energy available in current multi-Hz and near-future higher repetition-rate lasers(>kHz).Long-term drift was characterized at 100 Hz demonstrating suitability for operation over extended *** target was continuously operated at up to 5 Hz in a recent experiment for 70,000 shots without intervention by the experimental team,with the exception of tape replacement,producing the largest data-set of relativistically intense laser–solid foil measurements to *** tape drive provides robust targetry for the generation and study of high-repetitionrate ion beams using next-generation high-power laser systems,also enabling wider applications of laser-driven proton sources.

关键词： high-repetition-rate laser target laser-plasma acceleration proton generation tape-drive target

Structural effects of reedbed grazing and its cessation on reed-nesting songbird densities

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Avian research 2024年第2期15卷 238-248页

作者： Thomas Pagnon Clemence Pechinot Lea Sgro jeremie Demay remi jullian regis Gallais Brigitte Poulin Cyril Marmoex Theria Ecologie 6 avenue des martyrs05400VeynesFrance UMr 6249 Chrono-Environnement CNRSUniversite de Franche-Comte16 route de Gray25000BesanconFrance Conservatoire d’Espaces Naturels d’Occitanie 26 alle de Mycenes34000MontpellierFrance Office Français de la Biodiversite 12 cours Lumiere94300VincennesFrance Tour du Valat research Institute for the Conservation of Mediterranean Wetlands Le Sambuc13200ArlesFrance

reedbeds are crucial breeding habitats for vulnerable songbird *** of their protection status,these habitats may be threatened by organic matter accumulation,progressively leading to structural homoge-nization and habitat succession towards *** prevent excessive litter build-up with various in-terventions opening-up the reedbeds,such as grazing,which may be detrimental or suitable for some reed bird *** assessed the effects of extensive grazing by horses and its cessation in the medium and long terms on reedbed structure,and the consequences on reed-nesting songbird densities in Estagnol Nature reserve,a pro-tected wetland near the French Mediterranean *** compared reedbed structural features between grazed,newly ungrazed and old-ungrazed *** nine years,we censused four songbird species in spring and collected water level data in the same survey *** reduced reedbed extent,rejuvenated the vegetation with more short green stems on a thinner litter,and produced higher structural heterogeneity and discontinuity compared to long-lasting non *** ungrazed plot showed intermediate *** surveyed songbird total densities were similar among plots while species numbers and densities *** reedbed was more attractive to Moustached Warblers(Acrocephalus melanopogon)and Great reed Warblers(Acrocephalus arundi-naceus),likely due to the large edges and the high vegetation structural ***,Moustached Warblers were more negatively affected by higher water level in grazed reedbed,presumably because flooding prevents litter *** newly ungrazed reedbed was not preferred by any *** warbler species were found under low density in the old-ungrazed reedbed,where reed Buntings(Emberiza schoeniclus)were exclu-sively *** availability related to thick litter layer may explain this *** reed Warblers(Acrocephalus scirpaceus)were found everywhere in similar

关键词： Bird conservation Edge complexity Fragmentation Habitat management Horse grazing Phragmites australis reed passerine

The Triple Combination of Meropenem,Avibactam,and a Metallo-β-Lactamase Inhibitor Optimizes Antibacterial Coverage Against Different β-Lactamase Producers

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Engineering 2024年第7期38卷 124-132页

作者： Zhuoren Ling Alistair james Macdonald Farley Aditya Lankapalli Yanfang Zhang Shonnette Premchand-Branker Kate Cook Andrei Baran Charlotte gray-Hammerton Claudia Orbegozo rubio Edgars Suna jordan Mathias jürgen Brem Kirsty Sands Maria Nieto-rosado Maria Mykolaivna Trush Nadira Naznin rakhi Willames Martins Yuqing Zhou Christopher joseph Schofield Timothy Walsh Department of Biology&Ineos Oxford Institute for Antimicrobial research University of OxfordOxford OX13REUK Chemistry research Laboratory Department of Chemistry and the Ineos Oxford Institute for Antimicrobial ResearchUniversity of OxfordOxford OX13TAUK Latvian Institute of Organic Synthesis Riga LV-1006Latvia Department of Medical Microbiology Division of Infection and ImmunitySchool of MedicineCardiff UniversityCardiff CF144XNUK Enzymology and Applied Biocatalysis research Center Faculty of Chemistry and Chemical EngineeringBabes-Bolyai UniversityCluj-Napoca 400028Romania

This work explores the potential of a triple combination of meropenem(MEM),a novel metallo-blactamase(MBL)inhibitor(indole-2-carboxylate 58(InC58)),and a serine-b-lactamase(SBL)inhibitor(avibactam(AVI))for broad-spectrum activity against carbapenemase-producing bacteria.A diverse panel comprising MBL-and SBL-producing strains was used for susceptibility testing of the triple combination using the agar dilution *** frequency of resistance(For)to MEM combined with InC58 was *** were sequenced and tested for cross resistance,fitness,and the stability of the resistance *** with the double combinations of MEM plus an SBL or MBL inhibitor,the triple combination extended the spectrum of activity to most of the isolates bearing SBLs(oxacillinase-48(OXA-48)and Klebsiella pneumoniae carbapenemase-2(KPC-2))and MBLs(New Delhi metallo-blactamases(NDMs)),although it was not effective against Verona integron-encoded metallo-blactamase(VIM)-carrying Pseudomonas aeruginosa(***)and OXA-23-carrying Acinetobacter baumannii(***).The For to MEM plus InC58 ranged from 2.22×10^(-7)to 1.13×10^(-6).The resistance correlated with mutations to ompC and comr,affecting porin C and copper permeability,*** mutants manifested a fitness cost,a decreased level of resistance during passage without antibiotic pressure,and cross resistance to another carbapenem(imipenem)and a b-lactamase inhibitor(taniborbactam).In conclusion,compared with the dual combinations,the triple combination of MEM with InC58 and AVI showed a much wider spectrum of activity against different carbapenemaseproducing bacteria,revealing a new strategy to combat b-lactamase-mediated antimicrobial resistance.

关键词： Carbapenemase Metallo/serine-b-lactamase inhibitor Avibactam Meropenem Antimicrobial resistance