MacLaren S A, Schneider M B, Widmann K, Hammer J H, Yoxall B E, Moody J D, Bell P M, Benedetti L R, Bradley D K, Edwards M J, Guymer T M, Hinkel D E, Hsing W W, Kervin M L, Meezan N B, Moore A S, Ralph J E
Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA.
Atomic Weapons Establishment, Aldermaston, Reading RG7 4PR, United Kingdom.
Phys Rev Lett. 2014 Mar 14;112(10):105003. doi: 10.1103/PhysRevLett.112.105003. Epub 2014 Mar 13.
Indirect drive experiments at the National Ignition Facility are designed to achieve fusion by imploding a fuel capsule with x rays from a laser-driven hohlraum. Previous experiments have been unable to determine whether a deficit in measured ablator implosion velocity relative to simulations is due to inadequate models of the hohlraum or ablator physics. ViewFactor experiments allow for the first time a direct measure of the x-ray drive from the capsule point of view. The experiments show a 15%-25% deficit relative to simulations and thus explain nearly all of the disagreement with the velocity data. In addition, the data from this open geometry provide much greater constraints on a predictive model of laser-driven hohlraum performance than the nominal ignition target.
国家点火装置的间接驱动实验旨在通过用激光驱动的黑体辐射腔产生的X射线内爆燃料胶囊来实现核聚变。先前的实验无法确定测量到的烧蚀层内爆速度相对于模拟结果的不足是由于黑体辐射腔模型还是烧蚀层物理模型不完善所致。视因子实验首次允许从胶囊的角度直接测量X射线驱动。实验表明，相对于模拟结果存在15%-25%的不足，从而几乎解释了与速度数据的所有差异。此外，与标称点火靶相比，这种开放几何结构的数据对激光驱动黑体辐射腔性能的预测模型提供了更大的约束。
