Mitigation of mode-one asymmetry in laser-direct-drive inertial confinement fusion implosions
Mitigation of mode-one asymmetry in laser-direct-drive inertial confinement fusion implosions
复制标题
激光直接驱动惯性约束聚变内爆中模式一不对称性的缓解
作者：
O. Mannion;I. Igumenshchev;K. S. Anderson;R. Betti;E. Campbell;D. Cao;C. Forrest;M. G. Johnson;V. Glebov;V. Goncharov;V. Gopalaswamy;S. Ivancic;D. Jacobs;A. Kalb;J. Knauer;J. Kwiatkowski;A. Lees;F. Marshall;M. Michalko;Z. Mohamed;D. Patel;H. Rinderknecht;R. Shah;C. Stoeckl;W. Theobald;K. Woo;S. Regan
在激光驱动惯性约束聚变实验中，由于激光照射和目标的不均匀性导致目标的非对称压缩，从而导致热点等离子体的壳动能转化为热能的效率低下。在本文中，使用一套核和x射线诊断在OMEGA激光器上检查了低温氘氚激光直接驱动内爆的不对称压缩的影响。中子平均热点速度（u→hs）和表观离子温度（ti）不对称性由初等氘氚聚变中子能谱的中子飞行时间测量确定，热点周围压缩燃料的面密度（ρR）由散射中子能谱测量推断。热点形状的低模摄动是由沿着三条准正交的视线记录的x射线自发射图像表征的。具有明显的1模激光驱动不对称性的内爆显示出大的热点速度（>100 km/s），其方向与x射线图像中观察到的热点延伸率、测量到的t1不对称性和ρR不对称性一致。通过移动初始目标位置来应用激光驱动校正，以减轻观察到的不对称性。修正了不对称后，观察到一个更对称的热点，减小了u→hs， t1不对称，ρR不对称，熔合产率提高了30%。
Nonuniformities present in the laser illumination and target in laser-driven inertial confinement fusion experiments lead to an asymmetric compression of the target, resulting in an inefficient conversion of shell kinetic energy to thermal energy of the hot-spot plasma. In this paper, the effects of asymmetric compression of cryogenic deuterium tritium laser-direct-drive implosions are examined using a suite of nuclear and x-ray diagnostics on the OMEGA laser. The neutron-averaged hot-spot velocity ( u → hs) and apparent ion temperature ( T i) asymmetry are determined from neutron time-of-flight measurements of the primary deuterium tritium fusion neutron energy spectrum, while the areal density (ρR) of the compressed fuel surrounding the hot spot is inferred from measurements of the scattered neutron energy spectrum. The low-mode perturbations of the hot-spot shape are characterized from x-ray self-emission images recorded along three quasi-orthogonal lines of sight. Implosions with significant mode-1 laser-drive asymmetries show large hot-spot velocities (>100 km/s) in a direction consistent with the hot-spot elongation observed in x-ray images, measured T i asymmetry, and ρR asymmetry. Laser-drive corrections have been applied through shifting the initial target location in order to mitigate the observed asymmetry. With the asymmetry corrected, a more-symmetric hot spot is observed with reduced u → hs , T i asymmetry, ρR asymmetry, and a 30% increase in the fusion yield.
用于推断惯性约束聚变内爆等离子体特性的合成核诊断
影响因子：
2.2
作者：
Crilly A
通讯作者：
Crilly A
面密度不对称对 ICF 内爆散射中子能谱的影响
影响因子：
2.2
作者：
Crilly A
通讯作者：
Crilly A
中子反向散射边缘：ICF 实验中稠密 DT 燃料停滞时流体动力学特性的测量
影响因子：
2.2
作者：
Crilly A
通讯作者：
Crilly A