Observation of K-Shell Soft X Ray Emission of Nitrogen Irradiated by XUV-Free Electron Laser FLASH at Intensities Greater than 10 16 W/cm 2
Observation of K-Shell Soft X Ray Emission of Nitrogen Irradiated by XUV-Free Electron Laser FLASH at Intensities Greater than 10 16 W/cm 2
复制标题
强度大于 10 16 W/cm 2 的无 XUV 电子激光闪光照射氮气的 K 壳软 X 射线发射的观察
DOI：
10.1002/ctpp.201000045
复制
发表时间：
2011
影响因子：
1.6
通讯作者：
Galtier E
中科院分区：
文献类型：
--
作者：
Galtier E
在过去的几年里，第四代光源，即XUV/X射线自由电子激光器的发展为科学界提供了出色的工具，可以在实验室迄今为止从未获得的极端条件下研究物质。由于理论还处于起步阶段，通过目标的自发射来分析物质是至关重要的。如果光子能从介质中逃逸出来，那么这种致密物质的特征就有可能得到描述。由于K壳层X射线跃迁的吸收最小，因此它在本研究中起着关键作用。我们在这里报告了在430 eV处使用XUV自由电子激光器首次成功观察到氮的K壳层发射，以在特殊条件下照射固体氮化硼靶：光子能量为92 eV，脉冲持续时间为1020 fs，微聚焦导致强度大于1016 W/cm 2。使用耦合到CCD的THM的布拉格晶体，我们解析了来自不同电荷状态的K-壳层线发射。我们证明，当X射线辐射与固体物质相互作用时，光谱数据可以表征电子加热过程。由于光源是单色的，能量传输是不平凡的，因此这些结果对理论具有重要影响（© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA，魏因海姆）
In the past few years, the development of light sources of the 4thgeneration, namely XUV/X‐ray Free Electron Lasers provides to the scientific community outstanding tools to investigate matter under extreme conditions never obtained in laboratories so far. As theory is at its infancy, the analysis of matter via the self‐emission of the target is of central importance. The characterization of such dense matter is possible if photons can escape the medium. As the absorption of K‐shell X‐ray transitions is minimal, it plays a key role in this study. We report here the first successful observation of K‐shell emission of Nitrogen at 430 eV using an XUV‐Free Electron Laser to irradiate solid Boron Nitride targets under exceptional conditions: photon energy of 92 eV, pulse duration of ∼20 fs, micro focusing leading to intensities larger than 1016W/cm2. Using a Bragg crystal of THM coupled to a CCD, we resolved K‐shell line emission from different charge states. We demonstrate that the spectroscopic data allow characterization of electron heating processes when X‐ray radiation is interacting with solid matter. As energy transport is non‐trivial because the light source is monochromatic, these results have an important impact on the theory (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)