Anomalous Stabilization of Hydrodynamic Instability Due to Nonlocal Energy Transport

非局域能量传输引起的水动力不稳定性的反常稳定

• 批准号: 11480109
• 负责人: AZECHI Hiroshi
• 金额: $ 9.47万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11480109/
• 关键词: Rayleigh-Taylor instability; Nonlocal energy transport; High spatial resolution x-ray imaging; Laser fusion; Superwoman; 流体力学的不安定性; X線モアレ干渉

Suppression of hydrodynamic instability is critically important for the development of, inertial fusion energy. Before starting this research project, we found that the observed growth rates of the Rayleigh-Taylor instability were smaller than the theoretical predictions, and attributed to the nonlocal electron energy transport.Although the suppression of the growth rate itself is "good news" for laser fusion, it is unclear whether the same effect will be revealed in future reactor plasmas. The purpose of this research is to obtain good understanding to answer this question.For this purpose, we have performed the following three experiments.1. The suppression of growth rates is most pronounced in the short wavelength region. We have applied the innovated moire interferometry, and succeeded to observe the instability at short wavelengths. The growth rates have agreed well with the prediction that takes into account nonlocal electron transport.2. Direct evidence of nonlocal energy transport is critical. We have developed x-ray penumbral imaging and Fresnel phase zone plate imaging, and succeeded to measure plasma density. The observed density profiles were in better agreement with the prediction of nonlocal transport.3. Stability of targets for future reactors must be tested. We have developed a new laser system that combines all the existing laser beams so that a small portion of future target can be simulated, and measured the growth rates of Rayleigh-Taylor instability.Our activity to measure all necessary quantities to test various Rayleigh-Taylor instability theories are bearing fruit. Although there are some unresolved phenomena, the understanding of the ablative Rayleigh-Taylor instability that have been a central issue in more than a quarter century is approaching to "the end of the game".

抑制流体动力学不稳定性对于惯性聚变能的发展至关重要。在开始这个研究项目之前，我们发现观测到的瑞利-泰勒不稳定性的增长率小于理论预测，这归因于非局域电子能量传输。虽然抑制增长率本身对于激光聚变来说是“好消息”，但目前尚不清楚在未来的反应堆等离子体中是否会出现同样的效应。本研究的目的是为了更好地理解回答这个问题。为此，我们进行了以下三个实验： 1．生长速率的抑制在短波长区域最为明显。我们应用创新的莫尔干涉仪，成功地观察到了短波长的不稳定性。增长率与考虑非局域电子传输的预测非常吻合。2．非局域能源传输的直接证据至关重要。我们开发了X射线半影成像和菲涅耳相位波带板成像，并成功测量等离子体密度。观测到的密度剖面与非局域传输的预测更加吻合。3．必须测试未来反应堆目标的稳定性。我们开发了一种新的激光系统，它结合了所有现有的激光束，以便可以模拟未来目标的一小部分，并测量瑞利-泰勒不稳定性的增长率。我们测量所有必要量以测试各种瑞利-泰勒不稳定性理论的活动正在取得成果。尽管还存在一些未解决的现象，但对烧蚀瑞利-泰勒不稳定性的理解已经接近“游戏的终结”，这个问题在超过四分之一个世纪的时间里一直是一个中心问题。

项目成果

M.Nishikino, H.Shiraga, et al.: "Density Profile of the Ablating Plasma Produced by Soft X-Ray Irradiation"Review of Scientific Instruments. vol.72,No.1. 653-656 (2001)

M.Nishikino、H.Shiraga 等人：“软 X 射线照射产生的烧蚀等离子体的密度分布”科学仪器评论。

M.Nakai, H.Azechi, K.Shigemori et al.: "Experiments on Radiative Collapse in Laser-Produced Plasmas Relevant to Astrophysical Jets"Physics of Plasmas. (掲載受理). (2002)

M.Nakai、H.Azechi、K.Shigemori 等人：“与天体物理射流相关的激光产生的等离子体中的辐射塌陷实验”（已接受出版）。

M. Nishikino, H. Shiraga, M. Matsumoto, S. Fujioka, K. Shigemori, M. Nakai, H. Azechi, N. Miyanaga, and T. Yamanaka: "Density Profile of the Ablating Plasma Produced by Soft X-Ray Irradiation"Review of Scientific Instruments. 72. 653-656 (2001)

M. Nishikino、H. Shiraga、M. Matsumoto、S. Fujioka、K. Shigemori、M. Nakai、H. Azechi、N. Miyanaga 和 T. Yamanaka：“软 X 射线产生的烧蚀等离子体的密度分布

K.Shigemori et al.: "Feed-out of Rear Surface Perturbation due to Rarefaction Waves in Laser-Irradiated Targets"Physical Review Letters. Vol.84,No.23. 5331-5334 (2000)

K.Shigemori 等人：“激光照射目标中稀疏波引起的后表面扰动的反馈”物理评论快报。

M. Nakai, H. Azechi, N. Miyanaga, K. Shigemori et al.: "Single Spatial Mode Experiments on Initial Laser Imprint on Direct-Driven Planar Targets"Physics of Plasmas. (in press) 2002.

M. Nakai、H. Azechi、N. Miyanaga、K. Shigemori 等人：“直接驱动平面目标上初始激光印记的单空间模式实验”等离子体物理学。