Suppression of Hydrodynamic Instabilities by Controlling Vortices and Nonlocal Energy Transport

惯性聚变的概念是，用高功率激光照射聚变燃料制成的球形球团，使其表面发生内爆，从而组装高密度的主燃料和引发热核点火的热火花。流体动力学不稳定性，如烧蚀瑞利-泰勒不稳定性，可能潜在地阻止颗粒被压缩。因此，很好地理解和抑制不稳定性对惯性聚变的成功至关重要。在本课题开始之前，我们已经发现烧蚀瑞利-泰勒不稳定性被非局域电子热输运显著抑制。本研究的目的不只是接受这种效应是上帝的气息，而是有意探索和建立各种稳定方案。我们提出的方案依赖于热传导、辐射和对流的非局域性质。目前取得的成果有：1。对于非局部输运和内爆所需的高压产生，最佳激光波长…More是不同的。我们建议利用长波激光增强非局域效应，而短波激光产生高压。我们将这个方案命名为“鸡尾酒色照射”，并证明了它的良好效果（K. Otani，将发表在《物理学》上）。等离子体)。2。靶的x射线驱动也可以在牺牲能量效率的情况下抑制RT不稳定性。我们利用高掺z材料作为燃料球团本身，将x射线辐射抑制与高效内爆相结合。我们将该方案命名为“双烧蚀”，并证明了其良好的效果（S.Fujioka, physr . rev . lett）。04)。3。涡旋通过非局部化不稳定表面上的扰动来抑制不稳定性。只有这个问题还在调查中。除了这些活动外，我们还通过测量理论公式中出现的所有物理量，对RT不稳定性的各种理论进行了严格的检验。结果，我们发现长波扰动被它们的非定域性所抑制（H. Azechi, Phys.Rev.Lett）。07年)。回顾30年的活动，可以毫不夸张地说，对烧蚀瑞利-泰勒不稳定性的认识几乎已经达到了“游戏的终点”。当然，科学研究是虚拟的；例如，微扰本身的非局域化可能是一个非常有趣的课题。但在目前良好的认识进展下，我相信将抑制方案应用于激光聚变本身是更有成效的方向。少

The concept of inertial fusion is that a spherical pellet made of fusion fuel is imploded by irradiating the surface with high power lasers, thereby assembling a high-density main fuel and a hot spark triggering thermonuclear ignition. Hydrodynamic instabilities such as the ablative Rayleigh-Taylor instability may potentially prevent the pellet from being compressed. Good understanding and suppression of the instability is, therefore, critically important for the success of inertial fusion.At the stage before starting this research project, we had found that the ablative Rayleigh-Taylor instability is significantly suppressed by nonlocal electron heat transport. The purpose of the present research is not just to accept this effect as God's breath, but to intentionally explore and establish various stabilization schemes.The schemes that we have proposed rely on nonlocal nature of thermal conduction, radiation, and convection. The present achievements are :1.The optimum laser wavelength … More is different for nonlocal transport and for high pressure generation necessary for implosions. We propose to enhance nonlocal effect by long wavelength laser light, whereas the high pressure is generated by short wavelength laser light. We named this scheme "Cocktail Color Irradiation" and proved its favorable effect (K. Otani, to be published in Phys. Plasmas).2.The x-ray drive of the target can also suppress the RT instability at the sacrifice of energy efficiency. We combine the suppression by x-ray radiation and the high efficient implosion by utilizing high-Z doped material as the fuel pellet itself. We named this scheme "double ablation" and proved its favorable effect (S.Fujioka, Phys.Rev.Lett. 04).3.Vortices suppress the instability by nonlocalizing the perturbation on the unstable surface. Only this subject is still under investigation.4.In addition to these activities, we have rigorously tested various theories of the RT instability by measuring all physical quantities appeared in the theoretical formula. As a result, we have found that long wavelength perturbations are suppressed by their nonlocality (H. Azechi, Phys.Rev.Lett. 07).Recalling 30 years activities, it is not too much to say that the understanding of the ablative Rayleigh-Taylor instability has almost reached to "the end of the game". Of course, scientific research is virtually; nonlocalization of perturbations themselves, for instance, will probably be a very interesting subject. But at the present progress of the good understanding, I believe that applying the suppression schemes on laser fusion itself is the more productive direction. Less