The transport of sub-picosecond laser-driven fast electrons in nanopore array targets is studied. Attributed to the generation of micro-structured magnetic fields, most fast electron beams are proven to be effectively guided and restricted during the propagation. Different transport patterns of fast electrons in the targets are observed in experiments and reproduced by particle-in-cell simulations, representing two components: initially collimated low-energy electrons in the center and high-energy scattering electrons turning into surrounding annular beams. The critical energy for confined electrons is deduced theoretically. The electron guidance and confinement by the nano-structured targets offer a technological approach to manipulate and optimize the fast electron transport by properly modulating pulse parameters and target design, showing great potential in many applications including ion acceleration, microfocus x-ray sources and inertial confinement fusion.

研究了亚皮秒激光驱动的快速电子在纳米孔阵列目标中的传输。由于微结构磁场的产生，大多数快速电子束被证明在传播过程中被有效地引导和限制。在实验中观察到目标中快速电子的不同传输模式，并通过细胞内粒子模拟再现，代表两个组成部分：中心最初准直的低能电子和转变为周围环形光束的高能散射电子。受限电子的临界能量是从理论上推导出来的。纳米结构靶的电子引导和限制提供了一种通过适当调制脉冲参数和靶设计来操纵和优化快速电子传输的技术方法，