Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Phys Rev E. 2023 Jan;107(1):L013201. doi: 10.1103/PhysRevE.107.L013201.
The growth rate of the nonlinear ablative Rayleigh-Taylor (RT) instability is enhanced by magnetic fields self-generated by the Biermann battery mechanism; a scaling for this effect with perturbation height and wavelength is proposed and validated with extended-magnetohydrodynamic simulations. The magnetic flux generation rate around a single RT spike is found to scale with the spike height. The Hall parameter, which quantifies electron magnetization, is found to be strongly enhanced for short-wavelength spikes due to Nernst compression of the magnetic field at the spike tip. The impact of the magnetic field on spike growth is through both the suppressed thermal conduction into the unstable spike and the Righi-Leduc heat flow deflecting heat from the spike tip to the base. Righi-Leduc is found to be the dominant effect for small Hall parameters, while suppressed thermal conduction dominates for large Hall parameters. These results demonstrate the importance of considering magnetic fields in all perturbed inertial confinement fusion hot spots.
由比姆-萨伐尔机制自生的磁场会增强非线性烧蚀瑞利-泰勒（RT）不稳定性的增长率；提出了一种与微扰高度和波长相关的标度律，并通过扩展磁流体动力学模拟进行了验证。发现单个 RT 尖峰周围的磁通生成率与尖峰高度成正比。Hall 参数量化了电子的磁化强度，对于短波长的尖峰，由于在尖峰尖端的磁场的 Nernst 压缩，Hall 参数会强烈增强。磁场对尖峰生长的影响既通过抑制热传导进入不稳定的尖峰，也通过瑞利-利杜克热流将热量从尖峰尖端引导到基底来实现。对于小的 Hall 参数，发现瑞利-利杜克是主要效应，而对于大的 Hall 参数，抑制热传导则占主导地位。这些结果表明，在所有受扰惯性约束聚变热点中都必须考虑磁场的影响。
