Demonstration of a hydrodynamically equivalent burning plasma in direct-drive inertial confinement fusion
Demonstration of a hydrodynamically equivalent burning plasma in direct-drive inertial confinement fusion
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DOI：
10.1038/s41567-023-02361-4
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发表时间：
2024-02-05
期刊：
影响因子：
19.6
通讯作者：
Deeney，C.
中科院分区：
文献类型：
--
作者：
Gopalaswamy，V.;Williams，C. A.;Deeney，C.
将激光聚焦到充满氘和氚的小目标表面，使其内爆，并导致产生热而致密的等离子体，其中发生热核聚变反应。为了使等离子体能够自我维持，等离子体的加热必须由聚变反应提供的能量主导，这种情况被称为燃烧等离子体。广义劳森参数（英语：Generalized Lawson parameter）是一个度量，其数值高于0.8意味着等离子体燃烧。在这里，我们报告了OMEGA激光系统实验结果的水力等效缩放，并表明这些已经达到了核心条件，当等离子体的中心部分，热点，尺寸缩放至少3.9 ± 0.10倍时，达到燃烧等离子体，这将需要至少1.7 ± 0.13 MJ的驱动激光能量。此外，我们水力等效缩放的结果，在国家点火装置的激光能量为2.15兆焦耳，并发现这些内爆达到点火所需的劳森参数的86%。我们的研究结果支持直接驱动惯性约束聚变作为一种可靠的方法，实现热核点火和净能量的激光聚变。
Focussing laser light onto the surface of a small target filled with deuterium and tritium implodes it and leads to the creation of a hot and dense plasma, in which thermonuclear fusion reactions occur. In order for the plasma to become self-sustaining, the heating of the plasma must be dominated by the energy provided by the fusion reactions—a condition known as a burning plasma. A metric for this is the generalized Lawson parameter, where values above around 0.8 imply a burning plasma. Here, we report on hydro-equivalent scaling of experimental results on the OMEGA laser system and show that these have achieved core conditions that reach a burning plasma when the central part of the plasma, the hotspot, is scaled in size by at least a factor of 3.9 ± 0.10, which would require a driver laser energy of at least 1.7 ± 0.13 MJ. In addition, we hydro-equivalently scale the results to the 2.15 MJ of laser energy available at the National Ignition Facility and find that these implosions reach 86% of the Lawson parameter required for ignition. Our results support direct-drive inertial confinement fusion as a credible approach for achieving thermonuclear ignition and net energy in laser fusion.