Matter and Radiation at Extremes最新文献

{"title":"Exotic compounds of monovalent calcium synthesized at high pressure","authors":"Jun Kong, Kaiyuan Shi, Artem R. Oganov, Jiaqing Zhang, Lei Su, Xiao Dong","doi":"10.1063/5.0222230","DOIUrl":"https://doi.org/10.1063/5.0222230","url":null,"abstract":"It is well known that atoms of the same element in different valence states show very different chemical behaviors. Calcium is a typical divalent metal, sharing or losing both of its valence electrons when forming compounds. Attempts have been made to synthesize compounds of monovalent calcium ions for decades, but with very little success (e.g., in clusters). Pressure can result in substantial changes in the properties of atoms and chemical bonding, creating an extensive variety of unique materials with special valence states. In this study, using the ab initio evolutionary algorithm USPEX, we search for stable calcium–chlorine (Ca–Cl) system compounds at pressures up to 100 GPa. Besides the expected compound CaCl2, we predict three new compounds with monovalent Ca to be stable at high pressures, namely, CaCl, Ca5Cl6, and Ca3Cl4. According to our calculations, CaCl is stable at pressures above 18 GPa and is predicted to undergo a transition from nonmagnetic Fm-3m-CaCl to ferromagnetic Pm-3m-CaCl at 40 GPa. Ca5Cl6 and Ca3Cl4 are stable at pressures above 37 and 73 GPa, with space groups P-1 and R-3, respectively. Following these predictions, we successfully synthesized Pm-3m-CaCl in laser-heated diamond anvil cell experiments. The emergence of the unusual valence state at high pressures reveals exciting opportunities for creating entirely new materials in sufficiently large quantities for a variety of potential applications.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hollow ion atomic structure and X-ray emission in dense hot plasmas","authors":"Frank B. Rosmej, Christopher J. Fontes","doi":"10.1063/5.0226041","DOIUrl":"https://doi.org/10.1063/5.0226041","url":null,"abstract":"Hollow ion X-ray emission is of great interest in high-energy-density research, since negligible opacity allows studies from the interior of very dense objects. In this paper, ionization potential depressions of the isoelectronic sequences for single and double K-shell vacancies are obtained from a pure ab initio multiconfiguration Hartree–Fock simulation including exact exchange terms and finite temperature dense plasma effects. It is demonstrated that the simultaneous representation of these ab initio data in the form of a map of hollow ion X-ray transition energies enables identification of important steps in the matter evolution and ionization dynamics. Mapping along the isoelectronic sequence as a function of the pumping energy of a X-ray free electron laser also enables visualization of the impact of ionization potential depression on the pathways of hollow ion formation.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental measurements of gamma-photon production and estimation of electron/positron production on the PETAL laser facility","authors":"F. Brun, L. Ribotte, G. Boutoux, X. Davoine, P. E. Masson-Laborde, Y. Sentoku, N. Iwata, N. Blanchot, D. Batani, I. Lantuéjoul, L. Lecherbourg, B. Rosse, C. Rousseaux, B. Vauzour, D. Raffestin, E. D’Humières, X. Ribeyre","doi":"10.1063/5.0206416","DOIUrl":"https://doi.org/10.1063/5.0206416","url":null,"abstract":"This article reports the first measurements of high-energy photons produced with the high-intensity PETawatt Aquitaine Laser (PETAL) laser. The experiments were performed during the commissioning of the laser. The laser had an energy of about 400 J, an intensity of 8 × 1018 W cm−2, and a pulse duration of 660 fs (FWHM). It was shot at a 2 mm-thick solid tungsten target. The high-energy photons were produced mainly from the bremsstrahlung process for relativistic electrons accelerated inside a plasma generated on the front side of the target. This paper reports measurements of electrons, protons and photons. Hot electrons up to ≈35 MeV with a few-MeV temperature were recorded by a spectrometer, called SESAME (Spectre ÉlectronS Angulaire Moyenne Énergie). K- and L-shells were clearly detected by a photon spectrometer called SPECTIX (Spectromètre Petal à Cristal en TransmIssion pour le rayonnnement X). High-energy photons were diagnosed by CRACC-X (Cassette de RAdiographie Centre Chambre-rayonnement X), a bremsstrahlung cannon. Bremsstrahlung cannon analysis is strongly dependent on the hypothesis adopted for the spectral shape. Different shapes can exhibit similar reproductions of the experimental data. To eliminate dependence on the shape hypothesis and to facilitate analysis of the data, simulations of the interaction were performed. To model the mechanisms involved, a simulation chain including hydrodynamic, particle-in-cell, and Monte Carlo simulations was used. The simulations model the preplasma generated at the front of the target by the PETAL laser prepulse, the acceleration of electrons inside the plasma, the generation of MeV-range photons from these electrons, and the response of the detector impacted by the energetic photon beam. All this work enabled reproduction of the experimental data. The high-energy photons produced have a large emission angle and an exponential distribution shape. In addition to the analysis of the photon spectra, positron production was also investigated. Indeed, if high-energy photons are generated inside the solid target, some positron/electron pairs may be produced by the Bethe–Heitler process. Therefore, the positron production achievable within the PETAL laser facility was quantified. To conclude the study, the possibility of creating electron/positron pairs through the linear Breit–Wheeler process with PETAL was investigated.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benchmark simulations of radiative transfer in participating binary stochastic mixtures in two dimensions","authors":"Cong-Zhang Gao, Ying Cai, Cheng-Wu Huang, Yang Zhao, Jian-Wei Yin, Zheng-Feng Fan, Jia-Min Yang, Pei Wang, Shao-Ping Zhu","doi":"10.1063/5.0208236","DOIUrl":"https://doi.org/10.1063/5.0208236","url":null,"abstract":"We study radiative transfer in participating binary stochastic mixtures in two dimensions (2D) by developing an accurate and efficient simulation tool. For two different sets of physical parameters, 2D benchmark results are presented, and it is found that the influence of the stochastic mixture on radiative transfer is clearly parameter-dependent. Our results confirm that previous multidimensional results obtained in different studies are basically consistent, which is interpreted in terms of the relationship between the photon mean free path lp and the system size L. Nonlinear effects, including those due to scattering and radiation–material coupling, are also discussed. To further understand the particle size effect, we employ a dimensionless parameter lp/L, from which a critical particle size can be derived. On the basis of further 2D simulations, we find that an inhomogeneous mix is obtained for lp/L > 0.1. Furthermore, 2D material temperature distributions reveal that self-shielding and particle–particle shielding of radiation occur, and are enhanced when lp/L is increased. Our work is expected to provide benchmark results to verify proposed homogenized models and/or other codes for stochastic radiative transfer in realistic physical scenarios.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fundamental influence of irreversible stress–strain properties in solids on the validity of the ramp loading method","authors":"Jingxiang Shen, Wei Kang","doi":"10.1063/5.0210797","DOIUrl":"https://doi.org/10.1063/5.0210797","url":null,"abstract":"The widely used quasi-isentropic ramp loading technique relies heavily on back-calculation methods that convert the measured free-surface velocity profiles to the stress–density states inside the compressed sample. Existing back-calculation methods are based on one-dimensional isentropic hydrodynamic equations, which assume a well-defined functional relationship P(ρ) between the longitudinal stress and density throughout the entire flow field. However, this kind of idealized stress–density relation does not hold in general, because of the complexities introduced by structural phase transitions and/or elastic–plastic response. How and to what extent these standard back-calculation methods may be affected by such inherent complexities is still an unsettled question. Here, we present a close examination using large-scale molecular dynamics (MD) simulations that include the detailed physics of the irreversibly compressed solid samples. We back-calculate the stress–density relation from the MD-simulated rear surface velocity profiles and compare it directly against the stress–density trajectories measured from the MD simulation itself. Deviations exist in the cases studied here, and these turn out to be related to the irreversibility between compression and release. Rarefaction and compression waves are observed to propagate with different sound velocities in some parts of the flow field, violating the basic assumption of isentropic hydrodynamic models and thus leading to systematic back-calculation errors. In particular, the step-like feature of the P(ρ) curve corresponding to phase transition may be completely missed owing to these errors. This kind of mismatch between inherent properties of matter and the basic assumptions of isentropic hydrodynamics has a fundamental influence on how the ramp loading method can be applied.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical model of current propagation in a helical coil with varying geometry and screen tube","authors":"C. L. C. Lacoste, A. Hirsch, E. d’Humières, V. T. Tikhonchuk, P. Antici, M. Bardon","doi":"10.1063/5.0221820","DOIUrl":"https://doi.org/10.1063/5.0221820","url":null,"abstract":"An analytical model of current propagation in a helical coil with varying geometry is developed. It can be used for post-acceleration and post-focusing of ions produced via laser-driven target normal sheath acceleration and generation of electromagnetic pulses. We calculate the current that propagates in a helical coil and suggest a method for improving its dispersion properties using a screening tube and with pitch and radius variation. The electromagnetic fields calculated with the analytical model are in agreement with particle-in-cell simulations. The model provides insights into the physics of current propagation in helical coils with varying geometries and enables a numerical implementation for rapid proton spectrum computations, which facilitate the design of such coils for future experiments.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A distinctive HPHT platform with different types of large-volume press subsystems at SECUF","authors":"Yufei Ge, Shuailing Ma, Cun You, Kuo Hu, Chuang Liu, Yixuan Wang, Xinglin Wang, Xinyang Li, Hongyu Li, Qiang Tao, Shuqing Jiang, Lu Wang, Hu Tang, Di Yao, Zhi He, Xinyi Yang, Zhaodong Liu, Qiang Zhou, Pinwen Zhu, Bo Zou, Bingbing Liu, Tian Cui","doi":"10.1063/5.0205477","DOIUrl":"https://doi.org/10.1063/5.0205477","url":null,"abstract":"Large-volume presses (LVPs) providing large volumes, liquid media, deformation capability, jump compression, and in situ measurements are in great demand for high-pressure research, particularly in the fields of geoscience, condensed matter physics, material science, chemistry, and biology. A high-pressure and high-temperature (HPHT) platform with different LVP subsystems, both solid-state and liquid environments, and nonequilibrium subsystems, has been constructed at the Synergetic Extreme Condition User Facility, Jilin University. This article describes the construction of the different subsystems and provides an overview of the capabilities and characteristics of the different HPHT subsystems. A large sample volume (1000 mm3) at 20 GPa is achieved through the use of a belt-type apparatus in the solid-state subsystem. HPHT conditions (1.8 GPa and 1000 K) are realized in the liquid subsystem through the use of a piston–cylinder-type LVP with optical diamond windows for in situ spectroscopic measurements. A maximum pressure jump to 10.2 GPa can be reached within 20 ms in the nonequilibrium subsystem with the use of an improved bladder-pressurization jump press. Some typical results obtained with different LVPs are briefly reviewed to illustrate the applications and advantages of these presses. In summary, the platform described here has the potential to contribute greatly to high-pressure research and to innovations in high-pressure technology.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equation of state for boron nitride along the principal Hugoniot to 16 Mbar","authors":"Huan Zhang, Yutong Yang, Weimin Yang, Zanyang Guan, Xiaoxi Duan, Mengsheng Yang, Yonggang Liu, Jingxiang Shen, Katarzyna Batani, Diluka Singappuli, Ke Lan, Yongsheng Li, Wenyi Huo, Hao Liu, Yulong Li, Dong Yang, Sanwei Li, Zhebin Wang, Jiamin Yang, Zongqing Zhao, Weiyan Zhang, Liang Sun, Wei Kang, Dimitri Batani","doi":"10.1063/5.0206889","DOIUrl":"https://doi.org/10.1063/5.0206889","url":null,"abstract":"The thermodynamic properties of boron nitride under extreme pressures and temperatures are of great interest and importance for materials science and inertial confinement fusion physics, but they are poorly understood owing to the challenges of performing experiments and realizing ab initio calculations. Here, we report the first shock Hugoniot data on hexagonal boron nitride at pressures of 5–16 Mbar, using hohlraum-driven shock waves at the SGIII-p laser facility in China. Our density functional theory molecular dynamics calculations closely match experimental data, validating the equations of state for modeling the shock response of boron nitride and filling a crucial gap in the knowledge of boron nitride properties in the region of multi-Mbar pressures and eV temperatures. The results presented here provide fundamental insights into boron nitride under the extreme conditions relevant to inertial confinement fusion, hydrogen–boron fusion, and high-energy-density physics.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of nuclear isomer production in laser-induced plasma","authors":"Zhiguo Ma, Yumiao Wang, Yi Yang, Youjing Wang, Kai Zhao, Yixin Li, Changbo Fu, Wanbing He, Yu-Gang Ma","doi":"10.1063/5.0212163","DOIUrl":"https://doi.org/10.1063/5.0212163","url":null,"abstract":"Nuclear isomers play essential roles in various fields, including stellar nucleosynthesis, nuclear clocks, nuclear batteries, clean nuclear energy, and γ-ray lasers. Recent technological advances in high-intensity lasers have made it possible to excite or de-excite nuclear isomers using table-top laser equipment. Utilizing a particle-in-cell code, we investigate the interaction of a laser with a nanowire array and calculate the production rates of the 73mGe (E1 = 13.3 keV) and 107mAg (E1 = 93.1 keV) isomers. For 73m1Ge, production by Coulomb excitation is found to contribute a peak efficiency of 1.0 × 1019 particles s−1 J−1, while nuclear excitation by electron capture (NEEC) contributes a peak of 1.65 × 1011 particles s−1 J−1. These results indicate a high isomeric production ratio, as well as demonstrating the potential for confirming the existence of NEEC, a long-expected but so far experimentally unobserved fundamental process.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141926420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rescattering of stimulated Raman side scattering in nonuniform plasmas","authors":"S. Tan, Q. Wang, Y. Chen, W. B. Yao, C. Z. Xiao, J. F. Myatt","doi":"10.1063/5.0206740","DOIUrl":"https://doi.org/10.1063/5.0206740","url":null,"abstract":"Rescattering of stimulated Raman side scattering (SRSS) is observed for the first time via two-dimensional (2D) particle-in-cell (PIC) simulations. We construct a theoretical model for the rescattering process, which can predict the region of occurrence of mth-order SRSS and estimate its threshold. The rescattering process is identified by the 2D PIC simulations under typical conditions of a direct-drive inertial confinement fusion scheme. Hot electrons produced by second-order SRSS propagate nearly perpendicular to the density gradient and gain nearly the same energy as in first-order SRSS, but there is no cascade acceleration to produce superhot electrons. Parametric studies for a wide range of ignition conditions show that SRSS and associated rescatterings are robust and important processes in inertial confinement fusion.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":null,"pages":null},"PeriodicalIF":5.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}