论文标题
密集的电离物质中激光加速强度质子束的异常停止
Anomalous stopping of laser-accelerated intense proton beam in dense ionized matter
论文作者
论文摘要
超高强度激光器（10 $^{18} $ -10 $^{22} $ w/cm $^{2} $）在许多研究和应用程序[1-5]领域开辟了新的视角。通过辐照薄箔，可以形成一个超高加速场（10 $^{12} $ v/m），并在短时间（$ \ sim $ ps）上产生前所未有的高强度（10 $^{10} $ a/cm $^2 $）的多MEV离子[6-14]。这样的光束提供了射线照相[15]，高收益中子源[16]，高能量密度生成[17]和离子快速点火[18,19]的新选择。对物质中光束传输的非线性行为的准确理解对于所有这些应用至关重要。我们在这里报告了在特征良好的致密离子化物质中，激光产生的高电流质子束异常停止的第一个实验证据。观察到的停止功率是比单粒子减速理论预测高的数量级。我们将这一现象归因于集体效应，在密集的电离物质中，强烈的光束驱动接近1GV/m的电场下降。这一发现将对惯性融合能的未来途径产生相当大的影响。
Ultrahigh-intensity lasers (10$^{18}$-10$^{22}$W/cm$^{2}$) have opened up new perspectives in many fields of research and application [1-5]. By irradiating a thin foil, an ultrahigh accelerating field (10$^{12}$ V/m) can be formed and multi-MeV ions with unprecedentedly high intensity (10$^{10}$A/cm$^2$) in short time scale ($\sim$ps) are produced [6-14]. Such beams provide new options in radiography [15], high-yield neutron sources [16], high-energy-density-matter generation [17], and ion fast ignition [18,19]. An accurate understanding of the nonlinear behavior of beam transport in matter is crucial for all these applications. We report here the first experimental evidence of anomalous stopping of a laser-generated high-current proton beam in well-characterized dense ionized matter. The observed stopping power is one order of magnitude higher than single-particle slowing-down theory predictions. We attribute this phenomenon to collective effects where the intense beam drives an decelerating electric field approaching 1GV/m in the dense ionized matter. This finding will have considerable impact on the future path to inertial fusion energy.
