A 100 kJ-level laser facility has been designed to study inertial confinement fusion physics in China.This facility incorporates various diagnostic techniques,including optical,x-ray imaging,x-ray spectrum,and fusion ...A 100 kJ-level laser facility has been designed to study inertial confinement fusion physics in China.This facility incorporates various diagnostic techniques,including optical,x-ray imaging,x-ray spectrum,and fusion product diagnostics,as well as general diagnostics assistance systems and central control and data acquisition systems.This paper describes recent developments in diagnostics at the facility.展开更多
Wereport experimental research on laser plasma interaction(LPI)conducted in Shenguang laser facilities during the past ten years.The research generally consists of three phases:(1)developing platforms for LPI research...Wereport experimental research on laser plasma interaction(LPI)conducted in Shenguang laser facilities during the past ten years.The research generally consists of three phases:(1)developing platforms for LPI research in mm-scale plasma with limited drive energy,where both gasbag and gas-filled hohlraum targets are tested;(2)studying the effects of beam-smoothing techniques,such as continuous phase plate and polarization smoothing,on the suppression of LPI;and(3)exploring the factors affecting LPI in integrated implosion experiments,which include the laser intensity,gas-fill pressure,size of the laser-entrance hole,and interplay between different beam cones.Results obtained in each phase will be presented and discussed in detail.展开更多
In inertial confinement fusion(ICF),polycrystalline diamond-referred to as high density carbon(HDC)-has become a promising ablator candidate.However,with smaller grain size and lower initial density,the equation of st...In inertial confinement fusion(ICF),polycrystalline diamond-referred to as high density carbon(HDC)-has become a promising ablator candidate.However,with smaller grain size and lower initial density,the equation of state(EOS)for HDC can deviate from that for single-crystal diamond,which could be a concern for ICF designs,but current experimental EOS studies for HDC are far from sufficient to clarify how initial density affects target compressibility.Presented here are measurements of the Hugoniot for HDC with an initial density of 3.23 g/cm^(3) at pressures of 17–26 Mbar.Combined with experimental data reported for nanocrystalline diamond(NCD),a stiffer compressibility of NCD due to lower initial density is confirmed.Two porous models are used for comparison and seem to offer better agreement compared with SESAME databases.Also,the effect of temperature on the Gruneisen parameter,which is usually neglected,might need to be considered for NCD under these conditions.The present data offer important support for EOS studies relevant to ICF and constrain the construction of wide-range EOS.展开更多
Objective: A resilient health system plays a crucial role in pandemic preparedness and response. Althoughthe World Health Organization (WHO) has required all states parties to strengthen core capacities to respondto p...Objective: A resilient health system plays a crucial role in pandemic preparedness and response. Althoughthe World Health Organization (WHO) has required all states parties to strengthen core capacities to respondto public health emergencies under the International Health Regulations (2005), the actions of most countriesto combating coronavirus disease 2019 (COVID-19) has showed that they are not well-prepared. This crosssectionalstudy aimed to examine the health system resilience of selected countries and analyze their strategiesand measures in response to the COVID-19 pandemic.Methods: This study selected five countries including the Iran, Japan, Republic of Korea (South Korea), the U.K.,and the U.S., based on the severity of the national epidemic, the geographical location, and the developmentlevel. Cumulative number of death cases derived from WHO COVID-19 dashboard was used to measure theseverity of the impact of the pandemic in each country;WHO State Parties Self-Assessment Annual Reporting (SPAR)Scores and Global Health Security (GHS) Index were applied to measure the national health system resilience;and research articles and press materials were summarized to identify the strategies and measures adopted bycountries during response to COVID-19. This study applied the resilient health systems framework to analyzehealth system resilience in the selected countries from five dimensions, including awareness, diversity, selfregulation,integration and adaptation.Results: The SPAR Scores and GHS Index of the four developed countries, Japan, South Korea, the U.K. and theU.S. were above the global and regional averages;the SPAR Scores of Iran were above the global average whilethe GHI Index lain below the global average. In terms of response strategies, Japan, the U.K. and the U.S. investedmore health resources in the treatment of severe patients, while South Korea and Iran had adopted a strategyof extensive testing and identification of suspected patients. In terms of specific measures, all the five countriesadopted measures such as restrictions on entry and international travel, closure of schools and industries,lockdown and quarantine. Nevertheless, the effectiveness of implementing these measures varied acrosscountries, based on the response strategies.Conclusion: Although SPAR Scores and GHS Index have evaluated the national core capacities for preparednessand response, the actions to cope with the COVID-19 pandemic has revealed the fact that most countries stilldo not build resilient health systems in response to public health emergencies. Health system strengtheningand health security efforts should be pursued in tandem, as part of the same mutually reinforcing approach todeveloping resilient health systems.展开更多
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 ...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.展开更多
The comprehension of the composition and physical state of the deep interiors of large planets,as well as the impact events pertinent to planetary formation and evolution,necessitates an understanding of the propertie...The comprehension of the composition and physical state of the deep interiors of large planets,as well as the impact events pertinent to planetary formation and evolution,necessitates an understanding of the properties of planetary materials under extreme conditions.Forsterite(Mg2SiO4),a significant geological mineral,has not been fully characterized in terms of its behavior under shock compression due to a lack of consensus among previous experiments and simulations aimed at determining its Hugoniot,as well as the absence of knowledge of sound velocity at high pressures,a critical parameter indicative of phase transformation and melting.In this study,we delineated the Hugoniot curve of the mineral forsterite up to immense pressures of 1200 GPa.For the first time,we successfully constrained its sound velocity along the Hugoniot curve up to 760 GPa by combining laser-driven shock experiments with first-principles molecular dynamics simulations.The measured Hugoniot data for forsterite corroborated previous findings and suggested the occurrence of incongruent melting during shock compression.Remarkably,along their respective Hugoniot curves,the sound velocity of forsterite was observed to fall between that of the minerals bridgmanite and periclase.The remarkable agreement between the experimental results and simulation data provides reliable sound velocity measurements on the forsterite Hugoniot,which is critical for comprehensively understanding the phase transition and melting behavior of forsterite under ultra-high pressures.This knowledge sheds invaluable light on the behavior of this significant geological mineral under extreme conditions akin to those found in the interiors of planets.展开更多
基金This work was performed under the auspices of the National Key R&D Program of China,No.2017YFA0403300National Natural Science Foundation of China under Contract Nos.11805184,11805178,11805185+2 种基金Presidential Foundation of China Academy of Engineering Physics,No.YZJJLX2019011Science Challenging Project,No.TZ2016001Laser Fusion Research Center Funds for Young Talents,No.RCFPD4-2020-1.
文摘A 100 kJ-level laser facility has been designed to study inertial confinement fusion physics in China.This facility incorporates various diagnostic techniques,including optical,x-ray imaging,x-ray spectrum,and fusion product diagnostics,as well as general diagnostics assistance systems and central control and data acquisition systems.This paper describes recent developments in diagnostics at the facility.
基金This work was supported by the Science Challenge Project(Grant No.TZ2016005)the Natural Science Foundation of China(Grant Nos.11435011,11875093,and 11875241)the CAEP Foundation(Grant No.PY2019108).
文摘Wereport experimental research on laser plasma interaction(LPI)conducted in Shenguang laser facilities during the past ten years.The research generally consists of three phases:(1)developing platforms for LPI research in mm-scale plasma with limited drive energy,where both gasbag and gas-filled hohlraum targets are tested;(2)studying the effects of beam-smoothing techniques,such as continuous phase plate and polarization smoothing,on the suppression of LPI;and(3)exploring the factors affecting LPI in integrated implosion experiments,which include the laser intensity,gas-fill pressure,size of the laser-entrance hole,and interplay between different beam cones.Results obtained in each phase will be presented and discussed in detail.
基金supported by the National Key R&D Program of China(Grant No.2017YFA0403201)the Science Challenge Project(Grant No.TZ2016001)the National Natural Science Foundation of China(Grant Nos.11805183,12074351,and 11704351).
文摘In inertial confinement fusion(ICF),polycrystalline diamond-referred to as high density carbon(HDC)-has become a promising ablator candidate.However,with smaller grain size and lower initial density,the equation of state(EOS)for HDC can deviate from that for single-crystal diamond,which could be a concern for ICF designs,but current experimental EOS studies for HDC are far from sufficient to clarify how initial density affects target compressibility.Presented here are measurements of the Hugoniot for HDC with an initial density of 3.23 g/cm^(3) at pressures of 17–26 Mbar.Combined with experimental data reported for nanocrystalline diamond(NCD),a stiffer compressibility of NCD due to lower initial density is confirmed.Two porous models are used for comparison and seem to offer better agreement compared with SESAME databases.Also,the effect of temperature on the Gruneisen parameter,which is usually neglected,might need to be considered for NCD under these conditions.The present data offer important support for EOS studies relevant to ICF and constrain the construction of wide-range EOS.
基金supported by the National Natural Science Foundationof China (No. 72042014).
文摘Objective: A resilient health system plays a crucial role in pandemic preparedness and response. Althoughthe World Health Organization (WHO) has required all states parties to strengthen core capacities to respondto public health emergencies under the International Health Regulations (2005), the actions of most countriesto combating coronavirus disease 2019 (COVID-19) has showed that they are not well-prepared. This crosssectionalstudy aimed to examine the health system resilience of selected countries and analyze their strategiesand measures in response to the COVID-19 pandemic.Methods: This study selected five countries including the Iran, Japan, Republic of Korea (South Korea), the U.K.,and the U.S., based on the severity of the national epidemic, the geographical location, and the developmentlevel. Cumulative number of death cases derived from WHO COVID-19 dashboard was used to measure theseverity of the impact of the pandemic in each country;WHO State Parties Self-Assessment Annual Reporting (SPAR)Scores and Global Health Security (GHS) Index were applied to measure the national health system resilience;and research articles and press materials were summarized to identify the strategies and measures adopted bycountries during response to COVID-19. This study applied the resilient health systems framework to analyzehealth system resilience in the selected countries from five dimensions, including awareness, diversity, selfregulation,integration and adaptation.Results: The SPAR Scores and GHS Index of the four developed countries, Japan, South Korea, the U.K. and theU.S. were above the global and regional averages;the SPAR Scores of Iran were above the global average whilethe GHI Index lain below the global average. In terms of response strategies, Japan, the U.K. and the U.S. investedmore health resources in the treatment of severe patients, while South Korea and Iran had adopted a strategyof extensive testing and identification of suspected patients. In terms of specific measures, all the five countriesadopted measures such as restrictions on entry and international travel, closure of schools and industries,lockdown and quarantine. Nevertheless, the effectiveness of implementing these measures varied acrosscountries, based on the response strategies.Conclusion: Although SPAR Scores and GHS Index have evaluated the national core capacities for preparednessand response, the actions to cope with the COVID-19 pandemic has revealed the fact that most countries stilldo not build resilient health systems in response to public health emergencies. Health system strengtheningand health security efforts should be pursued in tandem, as part of the same mutually reinforcing approach todeveloping resilient health systems.
文摘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.
基金the financial support from the Natural Science Foundation of China(41925017)Toshimori Sekine acknowledges the financial support from Shanghai Key Laboratory of Material Frontiers Research in Extreme Environments,China(No.22dz2260800)+1 种基金Shanghai Science and Technology Committee,China(No.22JC1410300)the financial support from the Sichuan Science and Technology Program(No.2023NSFSC1910).
文摘The comprehension of the composition and physical state of the deep interiors of large planets,as well as the impact events pertinent to planetary formation and evolution,necessitates an understanding of the properties of planetary materials under extreme conditions.Forsterite(Mg2SiO4),a significant geological mineral,has not been fully characterized in terms of its behavior under shock compression due to a lack of consensus among previous experiments and simulations aimed at determining its Hugoniot,as well as the absence of knowledge of sound velocity at high pressures,a critical parameter indicative of phase transformation and melting.In this study,we delineated the Hugoniot curve of the mineral forsterite up to immense pressures of 1200 GPa.For the first time,we successfully constrained its sound velocity along the Hugoniot curve up to 760 GPa by combining laser-driven shock experiments with first-principles molecular dynamics simulations.The measured Hugoniot data for forsterite corroborated previous findings and suggested the occurrence of incongruent melting during shock compression.Remarkably,along their respective Hugoniot curves,the sound velocity of forsterite was observed to fall between that of the minerals bridgmanite and periclase.The remarkable agreement between the experimental results and simulation data provides reliable sound velocity measurements on the forsterite Hugoniot,which is critical for comprehensively understanding the phase transition and melting behavior of forsterite under ultra-high pressures.This knowledge sheds invaluable light on the behavior of this significant geological mineral under extreme conditions akin to those found in the interiors of planets.
