The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristi...The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristics of bound and continuum states in dense matter are modeled by a valence-band-like structure in a generalized ion-sphere approach with states that are either bound,free,or mixed.The self-consistent combination of this model with the Dirac wave equations of multielectron bound states allows one to fully respect the Pauli principle and to take into account the exact nonlocal exchange terms.The generalized method allows very high precision without implication of calibration shifts and scaling parameters and therefore has predictive power.This leads to new insights in the analysis of various data.The simple ionization model representing the K-edge is generalized to excitation–ionization phenomena resulting in an advanced interpretation of ionization depression data in near-solid-density plasmas.The model predicts scaling relations along the isoelectronic sequences and the existence of bound M-states that are in excellent agreement with experimental data,whereas other methods have failed.The application to unexplained data from compound materials also gives good agreement without the need to invoke any additional assumptions in the generalized model,whereas other methods have lacked consistency.展开更多
The 2024 MRE HP Special Volume selects papers on new theoretical and experimental developments in the use of static largevolume presses(LVPs)1–3 and dynamic compression4,5 for studies under extreme high-pressure and ...The 2024 MRE HP Special Volume selects papers on new theoretical and experimental developments in the use of static largevolume presses(LVPs)1–3 and dynamic compression4,5 for studies under extreme high-pressure and high-temperature(HPHT)conditions.It also continues the previous year’s6 contemporary focus on superhydrides7–11 with extremely high superconducting temperatures Tc and addresses some controversial issues.12–14 In addition,it explores unconventional pressure-induced chemistry,particularly novel chemical stoichiometry and its impact on geochemistry and cosmochemistry in the deep interiors of Earth and other planets.18–21.展开更多
Over the last two decades,the importance of fully ionized plasmas for the controlled manipulation of high-power coherent light has increased considerably.Many ideas have been put forward on how to control or change th...Over the last two decades,the importance of fully ionized plasmas for the controlled manipulation of high-power coherent light has increased considerably.Many ideas have been put forward on how to control or change the properties of laser pulses such as their frequency,spectrum,intensity,and polarization.The corresponding interaction with a plasma can take place either in a self-organizing way or by prior tailoring.Considerable work has been done in theoretical studies and in simulations,but at present there is a backlog of demand for experimental veri-fication and the associated detailed characterization of plasma-optical elements.Existing proof-of-principle experiments need to be pushed to higher power levels.There is little doubt that plasmas have huge potential for future use in high-power optics.This introduction to the special issue of Matter and Radiation at Extremes devoted to plasma optics sets the framework,gives a short historical overview,and briefly describes the various articles in this collection.展开更多
The use of plasmas provides a way to overcome the low damage threshold of classical solid-state based optical materials,which is the main limitation encountered in producing and manipulating intense and energetic lase...The use of plasmas provides a way to overcome the low damage threshold of classical solid-state based optical materials,which is the main limitation encountered in producing and manipulating intense and energetic laser pulses.Plasmas can directly amplify or alter the characteristics of ultra-short laser pulses via the three-wave coupling equations for parametric processes.The strong-coupling regime of Brillouin scattering(sc-SBS)is of particular interest:recent progress in this domain is presented here.This includes the role of the global phase in the spatio-temporal evolution of the three-wave coupled equations for backscattering that allows a description of the coupling dynamics and the various stages of amplification from the initial growth to the so-called self-similar regime.The understanding of the phase evolution allows control of the directionality of the energy transfer via the phase relation between the pulses.A scheme that exploits this coupling in order to use the plasma as a wave plate is also suggested.展开更多
Advanced X-ray spectroscopic methods provide unique and critical data to study matter under extreme environmental conditions induced by high-intensity and high-energy lasers.The aim of this paper is to contribute to a...Advanced X-ray spectroscopic methods provide unique and critical data to study matter under extreme environmental conditions induced by high-intensity and high-energy lasers.The aim of this paper is to contribute to a contemporary discussion of the role of X-ray spectroscopy in the investigation of radiative properties of strongly coupled,highly correlated,and frequently weakly emissive plasma systems formed in matter irradiated by sub-petawatt and petawatt class lasers.After reviewing the properties of different X-ray crystal spectrometers,high-resolution X-ray diagnostic methods are surveyed with respect to their potential to study plasmainduced and externally induced radiation fields,suprathermal electrons,and strong electromagnetic field effects.Atomic physics in dense plasmas is reviewed with emphasis on non-Maxwellian non-LTE atomic kinetics,quasi-stationary and highly-transient conditions,hollow ion X-ray emission,and field-perturbed atoms and ions.Finally,we discuss the role of X-ray free electron lasers with respect to supplementary investigations of matter under extreme conditions via the use of controlled high-intensity radiation fields.展开更多
Statistical models combined with the local plasma frequency approach applied to the atomic electron density are employed to study the photoionization cross-section for complex atoms.It is demonstrated that the Thomas...Statistical models combined with the local plasma frequency approach applied to the atomic electron density are employed to study the photoionization cross-section for complex atoms.It is demonstrated that the Thomas–Fermi atom provides surprisingly good overall agreement even for complex outer-shell configurations,where quantum mechanical approaches that include electron correlations are exceedingly difficult.Quantum mechanical photoionization calculations are studied with respect to energy and nl quantum number for hydrogen-like and non-hydrogen-like atoms and ions.Ageneralized scaled photoionizationmodel(GSPM)based on the simultaneous introduction of effective charges for non-H-like energies and scaling charges for the reduced energy scale allows the development of analytical formulas for all states nl.Explicit expressions for nl1s,2s,2p,3s,3p,3d,4s,4p,4d,4f,and 5s are obtained.Application to H-like and non-H-like atoms and ions and to neutral atoms demonstrates the universality of the scaled analytical approach including inner-shell photoionization.Likewise,GSPMdescribes the near-threshold behavior and high-energy asymptotes well.Finally,we discuss the various models and the correspondence principle along with experimental data and with respect to a good compromise between generality and precision.The results are also relevant to large-scale integrated light–matter interaction simulations,e.g.,X-ray free-electron laser interactions with matter or photoionization driven by a broadband radiation field such as Planckian radiation.展开更多
The theory of photoionization describing the interaction of x-ray free-electron laser(XFEL)pulses and high-harmonic-generated(HHG)radiation is generalized to ultrashort laser pulses,where the concept of the standard i...The theory of photoionization describing the interaction of x-ray free-electron laser(XFEL)pulses and high-harmonic-generated(HHG)radiation is generalized to ultrashort laser pulses,where the concept of the standard ionization probability per unit time in Fermi’s golden rule and in Einstein’s theory breaks down.Numerical calculations carried out in terms of a generalized photoionization probability for the total duration of pulses in the near-threshold regime demonstrate essentially nonlinear behavior,while absolute values may change by orders of magnitude for typical XFEL and HHG pulses.XFEL self-amplified spontaneous emission pulses are analyzed to reveal general features of photoionization for random and regular spikes:the dependences of the nonlinear photoionization probability on carrier frequency and spike duration are very similar,allowing an analytical expectation value approach that is valid even when there is only limited knowledge of random and regular parameters.Numerical simulations carried out for typical parameters demonstrate excellent agreement.展开更多
基金supported by the NSFC under Grant Nos.11374315 and 12074395the Invited Scientist Program of CNRS at Ecole Polytechnique,Palaiseau,France。
文摘The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristics of bound and continuum states in dense matter are modeled by a valence-band-like structure in a generalized ion-sphere approach with states that are either bound,free,or mixed.The self-consistent combination of this model with the Dirac wave equations of multielectron bound states allows one to fully respect the Pauli principle and to take into account the exact nonlocal exchange terms.The generalized method allows very high precision without implication of calibration shifts and scaling parameters and therefore has predictive power.This leads to new insights in the analysis of various data.The simple ionization model representing the K-edge is generalized to excitation–ionization phenomena resulting in an advanced interpretation of ionization depression data in near-solid-density plasmas.The model predicts scaling relations along the isoelectronic sequences and the existence of bound M-states that are in excellent agreement with experimental data,whereas other methods have failed.The application to unexplained data from compound materials also gives good agreement without the need to invoke any additional assumptions in the generalized model,whereas other methods have lacked consistency.
基金financial support from the Shanghai Key Laboratory of MFree,China(Grant No.22dz2260800)the Shanghai Science and Technology Committee,China(Grant No.22JC1410300).
文摘The 2024 MRE HP Special Volume selects papers on new theoretical and experimental developments in the use of static largevolume presses(LVPs)1–3 and dynamic compression4,5 for studies under extreme high-pressure and high-temperature(HPHT)conditions.It also continues the previous year’s6 contemporary focus on superhydrides7–11 with extremely high superconducting temperatures Tc and addresses some controversial issues.12–14 In addition,it explores unconventional pressure-induced chemistry,particularly novel chemical stoichiometry and its impact on geochemistry and cosmochemistry in the deep interiors of Earth and other planets.18–21.
基金support from the Federation Plas@par project and the support of Tremplin 2022 call(Sorbonne University,Science Faculty)support from the Advanced Research Using High Intensity Laser Produced Photons and Particles(ADONIS)Project(No.CZ.02.1.01/0.0/0.0/16_019/0000789)by the High Field Initiative Project(No.CZ.02.1.01/0.0/0.0/15_003/0000449)(HiFI),both from the European Regional Development Fund.
文摘Over the last two decades,the importance of fully ionized plasmas for the controlled manipulation of high-power coherent light has increased considerably.Many ideas have been put forward on how to control or change the properties of laser pulses such as their frequency,spectrum,intensity,and polarization.The corresponding interaction with a plasma can take place either in a self-organizing way or by prior tailoring.Considerable work has been done in theoretical studies and in simulations,but at present there is a backlog of demand for experimental veri-fication and the associated detailed characterization of plasma-optical elements.Existing proof-of-principle experiments need to be pushed to higher power levels.There is little doubt that plasmas have huge potential for future use in high-power optics.This introduction to the special issue of Matter and Radiation at Extremes devoted to plasma optics sets the framework,gives a short historical overview,and briefly describes the various articles in this collection.
基金This work has been done within the LABEX Plas@par project,and received financial state aid managed by the Agence Nationale de la Recherche,as part of the program“Investissements d’avenir”under the reference ANR-11-IDEX-0004-02.H.P.acknowledges the funding from China Scholarship Council.S.W.was supported by the project Advanced research using high intensity laser produced photons and particles(ADONIS)(CZ.02.1.01/0.0/0.0/16_019/0000789)from the European Regional Development Fund and by the project High Field Initiative(HiFI)(CZ.02.1.01/0.0/0.0/15_003/0000449)from the European Regional Development Fund.
文摘The use of plasmas provides a way to overcome the low damage threshold of classical solid-state based optical materials,which is the main limitation encountered in producing and manipulating intense and energetic laser pulses.Plasmas can directly amplify or alter the characteristics of ultra-short laser pulses via the three-wave coupling equations for parametric processes.The strong-coupling regime of Brillouin scattering(sc-SBS)is of particular interest:recent progress in this domain is presented here.This includes the role of the global phase in the spatio-temporal evolution of the three-wave coupled equations for backscattering that allows a description of the coupling dynamics and the various stages of amplification from the initial growth to the so-called self-similar regime.The understanding of the phase evolution allows control of the directionality of the energy transfer via the phase relation between the pulses.A scheme that exploits this coupling in order to use the plasma as a wave plate is also suggested.
基金One of the authors(O.R.)acknowledges support from the Czech Republic Ministry of Education,Youth and Sports within targeted support of Large Infrastructures,ELI Beamlines Project No.LQ1606 of the National Programme of Sustainability II,and Prague Asterix Laser System Project No.LM2015083.
文摘Advanced X-ray spectroscopic methods provide unique and critical data to study matter under extreme environmental conditions induced by high-intensity and high-energy lasers.The aim of this paper is to contribute to a contemporary discussion of the role of X-ray spectroscopy in the investigation of radiative properties of strongly coupled,highly correlated,and frequently weakly emissive plasma systems formed in matter irradiated by sub-petawatt and petawatt class lasers.After reviewing the properties of different X-ray crystal spectrometers,high-resolution X-ray diagnostic methods are surveyed with respect to their potential to study plasmainduced and externally induced radiation fields,suprathermal electrons,and strong electromagnetic field effects.Atomic physics in dense plasmas is reviewed with emphasis on non-Maxwellian non-LTE atomic kinetics,quasi-stationary and highly-transient conditions,hollow ion X-ray emission,and field-perturbed atoms and ions.Finally,we discuss the role of X-ray free electron lasers with respect to supplementary investigations of matter under extreme conditions via the use of controlled high-intensity radiation fields.
基金The work described here was supported by the Cooperation Agreement between the Sorbonne University,Faculty of Sciences(Pierre and Marie Curie)and the Moscow Institute of Physics and Technology MIPTFinancial support from MIPT in the framework of Grant No.075-02-2019-967 and the 5-top-100 program is greatly acknowledgedThis work has also been supported by the Competitiveness Program of NRNU MEPhI in the framework of the Russian Academic Excellence Project.
文摘Statistical models combined with the local plasma frequency approach applied to the atomic electron density are employed to study the photoionization cross-section for complex atoms.It is demonstrated that the Thomas–Fermi atom provides surprisingly good overall agreement even for complex outer-shell configurations,where quantum mechanical approaches that include electron correlations are exceedingly difficult.Quantum mechanical photoionization calculations are studied with respect to energy and nl quantum number for hydrogen-like and non-hydrogen-like atoms and ions.Ageneralized scaled photoionizationmodel(GSPM)based on the simultaneous introduction of effective charges for non-H-like energies and scaling charges for the reduced energy scale allows the development of analytical formulas for all states nl.Explicit expressions for nl1s,2s,2p,3s,3p,3d,4s,4p,4d,4f,and 5s are obtained.Application to H-like and non-H-like atoms and ions and to neutral atoms demonstrates the universality of the scaled analytical approach including inner-shell photoionization.Likewise,GSPMdescribes the near-threshold behavior and high-energy asymptotes well.Finally,we discuss the various models and the correspondence principle along with experimental data and with respect to a good compromise between generality and precision.The results are also relevant to large-scale integrated light–matter interaction simulations,e.g.,X-ray free-electron laser interactions with matter or photoionization driven by a broadband radiation field such as Planckian radiation.
基金funded by RFBR Grant No.19-32-90016,Ecole Polytechnique,the Cooperation Agreement between the Sorbonne University and MIPT,and the MIPT 5-top-100 programsupported by the Competitiveness Program of NRNU MEPhI in the framework of the Russian Academic Excellence Project.
文摘The theory of photoionization describing the interaction of x-ray free-electron laser(XFEL)pulses and high-harmonic-generated(HHG)radiation is generalized to ultrashort laser pulses,where the concept of the standard ionization probability per unit time in Fermi’s golden rule and in Einstein’s theory breaks down.Numerical calculations carried out in terms of a generalized photoionization probability for the total duration of pulses in the near-threshold regime demonstrate essentially nonlinear behavior,while absolute values may change by orders of magnitude for typical XFEL and HHG pulses.XFEL self-amplified spontaneous emission pulses are analyzed to reveal general features of photoionization for random and regular spikes:the dependences of the nonlinear photoionization probability on carrier frequency and spike duration are very similar,allowing an analytical expectation value approach that is valid even when there is only limited knowledge of random and regular parameters.Numerical simulations carried out for typical parameters demonstrate excellent agreement.
