Blast-wave-driven hydrodynamic instabilities are studied in the presence of a background B-field through experiments and simulations in the high-energy-density (HED) physics regime. In experiments conducted at the Laboratoire pour l’utilisation des lasers intenses (LULI), a laser-driven shock-tube platform was used to generate a hydrodynamically unstable interface with a prescribed sinusoidal surface perturbation, and short-pulse x-ray radiography was used to characterize the instability growth with and without a 10-T B-field. The LULI experiments were modeled in FLASH using resistive and ideal magnetohydrodynamics (MHD), and comparing the experiments and simulations suggests that the Spitzer model implemented in FLASH is necessary and sufficient for modeling these planar systems. These results suggest insufficient amplification of the seed B-field, due to resistive diffusion, to alter the hydrodynamic behavior. Although the ideal-MHD simulations did not represent the experiments accurately, they suggest that similar HED systems with dynamic plasma-β (=2μ₀ρv²/B²) values of less than ∼100 can reduce the growth of blast-wave-driven Rayleigh–Taylor instabilities. These findings validate the resistive-MHD FLASH modeling that is being used to design future experiments for studying B-field effects in HED plasmas.

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关于高能密度等离子体中背景磁场存在下的水动力不稳定性的研究

通过在高能量密度（HED）物理条件下的实验和模拟，研究了在背景B场存在下爆炸波驱动的水动力不稳定性。在激光强度实验室（LULI）进行的实验中，使用激光驱动的激波管平台生成具有规定正弦波表面扰动的流体动力学不稳定界面，并使用了短脉冲X射线照相技术表征有和没有10-T B场时的不稳定性增长。使用电阻和理想磁流体动力学（MHD）在FLASH中对LULI实验进行建模，并且比较实验和仿真结果表明，在FLASH中实施的Spitzer模型对于对这些平面系统进行建模是必要且充分的。这些结果表明，由于电阻扩散，种子B场的扩增不足，无法改变流体动力学行为。尽管理想的MHD模拟不能准确地代表实验，但它们表明，带有动态等离子体的类似HED系统β（= 2 μ ₀ ρV ² /乙²）小于约100的值可以减少爆炸波驱动的瑞利-泰勒不稳定的生长。这些发现验证了电阻MHD FLASH模型的有效性，该模型已用于设计未来的实验，以研究HED等离子体中的B场效应。