The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the pla...The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the plasma acceleration phase,shorter wavelengths lead to more efficien coupling between the laser and the kinetic energy of the implosion fluid Under the condition that the laser energy coupled to the implosion flui is constant,the ARTI growth rate decreases as the laser wavelength moves toward the extreme ultraviolet band,reaching its minimum value near λ=65 nm,and when the laser wavelength continuously moves toward the X-ray band,the ARTI growth rate increases rapidly.It is found that the results deviate from the theoretical ARTI growth rate.As the laser intensity benchmark increases,the position of the minimum ARTI growth rate shifts toward shorter wavelengths.As the initial sinusoidal perturbation wavenumber decreases,the position of the minimum ARTI growth rate shifts toward longer wavelengths.We believe that the conclusions drawn from the present simulations and analysis will help provide a better understanding of the ICF process and improve the theory of ARTI growth.展开更多
In the direct drive inertial confinement fusion(ICF)scheme,a rippled interface between the ablator and the deuterium–tritium ice fuel can feed out and form perturbation seeds for the ablative Rayleigh–Taylor instabi...In the direct drive inertial confinement fusion(ICF)scheme,a rippled interface between the ablator and the deuterium–tritium ice fuel can feed out and form perturbation seeds for the ablative Rayleigh–Taylor instability,with undesirable effects.However,the evolution of this instability remains insufficiently studied,and the effects of high-Z dopant on this instability remain unclear.In this paper,we develop a theoretical model to calculate the feedout seeds and describe this instability.Our theory suggests that the feedout seeds are determined by the ablation pressure and the adiabatic index,while the subsequent growth depends mainly on the ablation velocity.Two-dimensional radiation hydrodynamic simulations confirm our theory.It is shown that targets with high-Z dopant in the outer ablator exhibit more severe feedout seeds,because of their higher ionization compared with undoped targets.The X-ray pre-ablation in high-Z doped targets significantly suppresses subsequent growth,leading to suppression of short-wavelength perturbations.However,for long-wavelength perturbations,this suppression is weakened,resulting in increased instability in high-Z doped targets.The results are helpful for understanding the innerinterface-initiated instability and the influence of high-Z dopant on it,providing valuable insights for target design and instability control in ICF.展开更多
利用刀切法和Bayes估计方法,在加权平方损失函数下,得到Rayleigh分布在选取先验分布为Jefferys无信息分布和Gamma分布的情况下参数的Bayes估计的精确形式,在此基础上进一步研究了参数的刀切Bayes估计.最后在R软件中运用MCMC(Markov Chai...利用刀切法和Bayes估计方法,在加权平方损失函数下,得到Rayleigh分布在选取先验分布为Jefferys无信息分布和Gamma分布的情况下参数的Bayes估计的精确形式,在此基础上进一步研究了参数的刀切Bayes估计.最后在R软件中运用MCMC(Markov Chain Monte Carlo)算法对Rayleigh分布参数的Bayes估计和刀切Bayes估计进行数值模拟.模拟结果显示:当样本容量较大时,相同先验分布下刀切Bayes估计模拟效果更好.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.12074399,12204500,and 12004403)the Key Projects of the Intergovernmental International Scientifi and Technological Innovation Cooperation(Grant No.2021YFE0116700)+1 种基金the Shanghai Natural Science Foundation(Grant No.20ZR1464400)the Shanghai Sailing Program(Grant No.22YF1455300)。
文摘The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the plasma acceleration phase,shorter wavelengths lead to more efficien coupling between the laser and the kinetic energy of the implosion fluid Under the condition that the laser energy coupled to the implosion flui is constant,the ARTI growth rate decreases as the laser wavelength moves toward the extreme ultraviolet band,reaching its minimum value near λ=65 nm,and when the laser wavelength continuously moves toward the X-ray band,the ARTI growth rate increases rapidly.It is found that the results deviate from the theoretical ARTI growth rate.As the laser intensity benchmark increases,the position of the minimum ARTI growth rate shifts toward shorter wavelengths.As the initial sinusoidal perturbation wavenumber decreases,the position of the minimum ARTI growth rate shifts toward longer wavelengths.We believe that the conclusions drawn from the present simulations and analysis will help provide a better understanding of the ICF process and improve the theory of ARTI growth.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Science(Grant Nos.XDA25050200 and XDA25010100)the National Natural Science Foundation of China(Grant Nos.12175309,12475252,and 12275356)+2 种基金the Defense Industrial Technology Development Program(Grant No.JCKYS2023212807)the Natural Science Foundation of Hunan Province,China(Grant No.2025JJ20007)the Postgraduate Scientific Research Innovation Project of Hunan Province,China(Grant No.CX20230005).
文摘In the direct drive inertial confinement fusion(ICF)scheme,a rippled interface between the ablator and the deuterium–tritium ice fuel can feed out and form perturbation seeds for the ablative Rayleigh–Taylor instability,with undesirable effects.However,the evolution of this instability remains insufficiently studied,and the effects of high-Z dopant on this instability remain unclear.In this paper,we develop a theoretical model to calculate the feedout seeds and describe this instability.Our theory suggests that the feedout seeds are determined by the ablation pressure and the adiabatic index,while the subsequent growth depends mainly on the ablation velocity.Two-dimensional radiation hydrodynamic simulations confirm our theory.It is shown that targets with high-Z dopant in the outer ablator exhibit more severe feedout seeds,because of their higher ionization compared with undoped targets.The X-ray pre-ablation in high-Z doped targets significantly suppresses subsequent growth,leading to suppression of short-wavelength perturbations.However,for long-wavelength perturbations,this suppression is weakened,resulting in increased instability in high-Z doped targets.The results are helpful for understanding the innerinterface-initiated instability and the influence of high-Z dopant on it,providing valuable insights for target design and instability control in ICF.
文摘利用刀切法和Bayes估计方法,在加权平方损失函数下,得到Rayleigh分布在选取先验分布为Jefferys无信息分布和Gamma分布的情况下参数的Bayes估计的精确形式,在此基础上进一步研究了参数的刀切Bayes估计.最后在R软件中运用MCMC(Markov Chain Monte Carlo)算法对Rayleigh分布参数的Bayes估计和刀切Bayes估计进行数值模拟.模拟结果显示:当样本容量较大时,相同先验分布下刀切Bayes估计模拟效果更好.
