Univ Bordeaux, CNRS, CEA, CELIA, Centre Lasers Intenses et Applications, UMR 5107, F-33405 Talence, France.
Phys Rev Lett. 2012 Dec 21;109(25):255002. doi: 10.1103/PhysRevLett.109.255002. Epub 2012 Dec 18.
We present experimental and numerical results on intense-laser-pulse-produced fast electron beams transport through aluminum samples, either solid or compressed and heated by laser-induced planar shock propagation. Thanks to absolute K(α) yield measurements and its very good agreement with results from numerical simulations, we quantify the collisional and resistive fast electron stopping powers: for electron current densities of ≈ 8 × 10(10) A/cm(2) they reach 1.5 keV/μm and 0.8 keV/μm, respectively. For higher current densities up to 10(12)A/cm(2), numerical simulations show resistive and collisional energy losses at comparable levels. Analytical estimations predict the resistive stopping power will be kept on the level of 1 keV/μm for electron current densities of 10(14)A/cm(2), representative of the full-scale conditions in the fast ignition of inertially confined fusion targets.
我们呈现了实验和数值结果，研究了强激光脉冲产生的快电子束在穿过铝样品时的传输情况，这些样品要么是固态的，要么是通过激光诱导的平面冲击波传播压缩和加热的。由于绝对 K(α)产额的测量及其与数值模拟结果非常好的一致性，我们量化了碰撞和电阻对快电子的阻止本领：对于约 8×10(10)A/cm(2)的电子电流密度，它们分别达到 1.5 keV/μm 和 0.8 keV/μm。对于高达 10(12)A/cm(2)的更高电流密度，数值模拟显示电阻和碰撞能量损失处于相当水平。分析估计预测，对于代表惯性约束聚变靶中快速点火全尺寸条件的 10(14)A/cm(2)的电子电流密度，电阻阻止本领将保持在 1 keV/μm 的水平。
