Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080, China.
Phys Rev Lett. 2010 May 28;104(21):215004. doi: 10.1103/PhysRevLett.104.215004. Epub 2010 May 27.
Bright Ar quasimonochromatic K-shell x ray with very little background has been generated using an Ar clustering gas jet target irradiated with a 30 fs ultrahigh-contrast laser, with a measured flux of 2.2×10(11) photons/J into 4π. This intense x-ray source critically depends on the laser contrast and intensity. The optimization of source output with interaction length is addressed. Simulations point to a nonlinear resonant mechanism of electron heating during the early stage of laser interaction, resulting in enhanced x-ray emission. The x-ray pulse duration is expected to be only 10 fs, opening the possibility for single-shot ultrafast keV x-ray imaging applications.
已使用经 30fs 超高峰值对比度激光辐照的 Ar 团簇气体射流靶，产生了明亮的准单色 K 壳层 X 射线，其本底非常小，测量通量为 2.2×10(11)光子/J 到 4π。这种强 X 射线源严重依赖于激光对比度和强度。文中讨论了通过相互作用长度对源输出进行优化。模拟表明，在激光相互作用的早期阶段存在电子加热的非线性共振机制，从而增强了 X 射线发射。X 射线脉冲持续时间预计只有 10fs，这为单次超快 keV X 射线成像应用开辟了可能性。
