Plasma kinetics, pre-heat, and the emergence of strong shocks in laser fusion: the hydro-kinetic regime

激光聚变中的等离子体动力学、预热和强冲击的出现：流体动力学状态

• 批准号: EP/P023460/1
• 负责人: Robbie Scott
• 金额: $ 78.15万
• 依托单位: Science and Technology Facilities Council
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP023460%2F1
• 关键词: Plasma; kinetics; pre; heat; emergence

The goal of Laser Inertial Confinement Fusion (ICF) is to create and ignite a minute star. The energy liberated through thermonuclear fusion can be harnessed, providing mankind with an essentially limitless source of safe, sustainable, secure, carbon-free, electricity. If realised, laser-fusion would not only provide a solution to global warming, but enable the UK to become a net energy exporter, and also create a new market in ultra-high-tech technology exports in areas where the UK is currently world-leading, such as laser and targetry manufacture.The multi-billion dollar National Ignition Facility (NIF) is currently the only laser which, in principal, has sufficient energy to achieve ignition (where the 'star' burns), although to-date NIF has not achieved ignition. The base-line 'indirect-drive' NIF design uses an array of laser beams to create x-rays in a metallic cylinder (hohlraum), these x-rays in turn ablate the spherical ICF target, driving a convergent implosion. This causes the target to be compressed, creating density and temperature conditions similar to those within the centre of the Sun, thereby igniting the 'star'. While there are some advantages to the indirect-drive approach to ICF, it is extremely inefficient, and it is currently unclear whether it will be possible to achieve indirect drive ignition with the laser energy available on NIF. Alternative ICF schemes exist including 'direct drive' and 'shock ignition'. Here, the lasers directly illuminate the target improving efficiency by a factor of ~5, meaning it should be possible to achieve ignition with NIF's energy. Shock ignition is a recently invented variant of direct drive. Here the implosion velocity can be lower than the minimum required for ignition, instead ignition is initiated by a strong shock launched towards the end of the implosion. Shock ignition has many potential advantages over other ICF schemes; the laser energy requirements for ignition are well within those possible on NIF, as the implosion velocity can be lower, the susceptibility to deleterious fluid instabilities (Rayleigh-Taylor) is also reduced. Importantly, the energy gain (fusion energy out/electrical energy in) should be sufficient for power generation.Laser-plasma interaction instabilities (LPI) such as Stimulated Raman Scatter, Two Plasmon Decay and Stimulated Brillouin Scatter occur in all ICF schemes. These LPIs alter the temporospatial characteristics of laser absorption and can create significant populations of energetic (or hot) electrons. Determining the characteristics of the LPIs and the associated hot electrons is of critical importance for ICF as they dictate whether the fusion fuel will be heated prior to the fuel being compressed (pre-heat) - potentially precluding ignition - or whether the hot electrons' energy can be harnessed, enhancing shock generation in the shock ignition scheme, potentially leading to fusion energy gains sufficient for energy applications on today's lasers. This crucial area of ICF physics is the focus of this proposal. New experiments on the Omega laser facility will measure the LPI and hot electron characteristics in the parameter spaces of ignition-scale direct drive and shock ignition. A key outcome will be the encapsulation of the experimental data in innovative new laser-plasma interaction and hot electron simulation models, which will run in-line with the UK's radiation-hydrodynamics code framework: Odin. These will significantly improve our predictive simulation capabilities, providing benchmarked, high-fidelity simulation tools which will be made openly available to the UK academic laser-plasma physics community. This work, with direct involvement and leadership of ICF experiments on large scale facilities, provides a clear route by which the UK community can attain the skills, expertise, and tools to develop next-generation ICF designs for, and execute experiments on, the world's largest largest lasers into the 2020s.

激光惯性约束聚变（ICF）的目标是产生并点燃微小星星。通过热核聚变释放的能量可以被利用，为人类提供基本上无限的安全，可持续，安全，无碳的电力来源。如果实现，激光聚变不仅可以解决全球变暖问题，还可以使英国成为能源净出口国，并在英国目前处于世界领先地位的领域（如激光和靶制造）创造一个新的超高科技出口市场。耗资数十亿美元的国家点火装置（NIF）是目前唯一一个原则上具有足够的能量来实现点火（其中“星星”燃烧），尽管迄今为止NIF还没有实现点火。基线“间接驱动”NIF设计使用激光束阵列在金属圆柱体（黑腔）中产生X射线，这些X射线反过来烧蚀球形ICF靶，驱动会聚内爆。这导致目标被压缩，产生类似于太阳中心的密度和温度条件，从而点燃“恒星”。虽然间接驱动ICF方法有一些优点，但效率极低，目前还不清楚是否有可能利用NIF上的激光能量实现间接驱动点火。其他ICF方案包括“直接驱动”和“冲击点火”。在这里，激光器直接照射目标，将效率提高了约5倍，这意味着应该可以用NIF的能量实现点火。冲击点火是最近发明的直接驱动的一种变型。在这里，内爆速度可以低于点火所需的最小值，相反，点火是由内爆结束时发射的强冲击波引发的。激波点火比其他ICF方案具有许多潜在的优势;点火所需的激光能量完全在NIF方案的可能范围内，因为内爆速度可以更低，对有害流体不稳定性（瑞利-泰勒）的敏感性也降低了。激光等离子体相互作用不稳定性（LPI），如受激拉曼散射、双等离子体衰变和受激布里渊散射，在所有的ICF方案中都存在。这些LPI改变了激光吸收的时空特性，并可以产生大量的高能（或热）电子。确定LPI和相关热电子的特性对于ICF至关重要，因为它们决定了聚变燃料是否在被压缩之前被加热（预热）-潜在地排除点火-或者热电子的能量是否可以被利用，增强冲击点火方案中的冲击产生，潜在地导致足以用于当今激光器上的能量应用的聚变能量增益。ICF物理学的这一关键领域是本提案的重点。Omega激光设施上的新实验将测量点火尺度直接驱动和冲击点火参数空间中的LPI和热电子特性。一个关键成果将是将实验数据封装在创新的新激光-等离子体相互作用和热电子模拟模型中，该模型将与英国的辐射流体动力学代码框架Odin保持一致。这将大大提高我们的预测模拟能力，提供基准，高保真度的模拟工具，将公开提供给英国学术激光等离子体物理社区。这项工作，与ICF实验的直接参与和领导的大规模设施，提供了一个明确的路线，英国社区可以获得的技能，专业知识和工具，开发下一代ICF设计，并执行实验，世界上最大的最大的激光器到2020年代。

项目成果

Stimulated Raman scattering mechanisms and scaling behavior in planar direct-drive experiments at the National Ignition Facility

• DOI: 10.1063/1.5139226
• 发表时间: 2020-04
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: M. Rosenberg;A. Solodov;W. Seka;R. Follett;J. Myatt;A. Maximov;C. Ren;S. Cao;P. Michel;M. Hohenberger;J. Palastro;C. Goyon;T. Chapman;J. Ralph;J. Moody;R. Scott;K. Glize;S. Regan

Modelling burning thermonuclear plasma

• DOI: 10.1098/rsta.2020.0014
• 发表时间: 2020-11-13
• 期刊: PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
• 影响因子: 5
• 作者: Rose, S. J.;Hatfield, P. W.;Scott, R. H. H.
• 通讯作者: Scott, R. H. H.

The blind implosion-maker: Automated inertial confinement fusion experiment design

• DOI: 10.1063/1.5091985
• 发表时间: 2019-06-01
• 期刊: PHYSICS OF PLASMAS
• 影响因子: 2.2
• 作者: Hatfield, P. W.;Rose, S. J.;Scott, R. H. H.
• 通讯作者: Scott, R. H. H.

One-dimensional hydrodynamic simulations of low convergence ratio direct-drive inertial confinement fusion implosions.

低收敛比直接驱动惯性限制融合内爆的一维水动力模拟。

• DOI: 10.1098/rsta.2020.0224
• 发表时间: 2021-01-25
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Paddock RW;Martin H;Ruskov RT;Scott RHH;Garbett W;Haines BM;Zylstra AB;Aboushelbaya R;Mayr MW;Spiers BT;Wang RHW;Norreys PA
• 通讯作者: Norreys PA

Collisionless shock acceleration in the corona of an inertial confinement fusion pellet with possible application to ion fast ignition.

惯性限制融合颗粒的电晕中的无碰撞冲击加速度可能应用于离子快速点火。

• DOI: 10.1098/rsta.2020.0039
• 发表时间: 2021-01-25
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Boella E;Bingham R;Cairns RA;Norreys P;Trines R;Scott R;Vranic M;Shukla N;Silva LO
• 通讯作者: Silva LO