论文标题
超短，MEV尺度激光 - 汗水正电子源，用于正电子歼灭寿命光谱法
Ultra-short, MeV-scale laser-plasma positron source for positron annihilation lifetime spectroscopy
论文作者
论文摘要
亚微米缺陷代表了制造业中众所周知的基本问题，因为它们几乎可以显着影响任何高价值组件的性能和寿命。正电子歼灭寿命光谱可以说是唯一能够检测到亚纳米尺度的缺陷的唯一已建立的方法，但迄今为止，它仅适用于表面研究且分辨率有限。在这里，我们通过实验和数字表明，激光驱动的系统可以通过生成可将500 keV至2 meV的动能调谐的超短效率束来克服这些众所周知的局限性，每次以50 kev Energe slice slice slice \ color {black}的命中率每次拍摄，$ 10^3^3 $ 10^3 $。对典型MJ尺度KHz激光器的预期性能的数值模拟证明了产生超过$ 10^5 $ pocitrons/s的MEV尺度窄带和超短声音梁，以高分辨率的快速体积扫描材料的快速扫描。
Sub-micron defects represent a well-known fundamental problem in manufacturing since they can significantly affect performance and lifetime of virtually any high-value component. Positron annihilation lifetime spectroscopy is arguably the only established method capable of detecting defects down to the sub-nanometer scale but, to date, it only works for surface studies, and with limited resolution. Here, we experimentally and numerically show that laser-driven systems can overcome these well-known limitations, by generating ultra-short positron beams with a kinetic energy tuneable from 500 keV up to 2 MeV and a number of positrons per shot in a 50 keV energy slice \color{black} of the order of $10^3$. Numerical simulations of the expected performance of a typical mJ-scale kHz laser demonstrate the possibility of generating MeV-scale narrow-band and ultra-short positron beams with a flux exceeding $10^5$ positrons/s, of interest for fast volumetric scanning of materials at high resolution.
