Soft X-ray Laser by Hybrid Excitation Method Using Laser Produced Multiple Charged Ions

使用激光产生多带电离子的混合激发方法的软 X 射线激光器

基本信息

批准号：
08650054
负责人：
KUBODERA Shoichi
金额：
$ 1.15万
依托单位：
Miyazaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650054/
关键词：
High Intensity Laser Ultrashort Pulse Laser Soft X-ray Laser Multiple Charged Ion Rare Gas Excimer Vacuum Ultraviolet Laser レーザー生成多価イオン軟X線電子ビーム発生装置放電励起

项目摘要

I have proposed a hybrid excitation method as a new method to realize a soft x-ray laser where high intensity laser produced multiple charged ions are further excited by electrical power from a compact discharge device.As a result of the interaction of Ar and high intensity laser field, I have observed emission from Ar_2^<**> at 126 nm for the first time together with some signals of high order harmonics. The focused laser intensity dependence of the Ar excimer intensity agrees well with that predicted by a tunnel ionization theory so called ADK theory. I,therefore, found out that the production of Ar excimers was initiated by high intensity laser produced electrons, which may become a substitution to those produced by an electron beam device.It is well known that the electron temperature as a result of tunnel ionization is very sensitive to laser intensity, wavelength, and polarization. Experimental data, however, show no difference in terms of the Ar excimer emission when linearly po … More larized and circularly polarized laser beams interacted with Ar. Considering about the energy transport of electrons in a high intensity laser produced plasma theoretically, I have found out a rapid conductive cooling of a plasma plays an important role for the excimer production. A cooling time constant for the appropriate excimer production is much faster than the three body recombination time constant which is a main production process of the excimers.In order to simulate an interaction between x-ray emission from a discharge plasma and rare gas (Kr), an x-ray source using laser produced plasma was used as a compact x-ray source. When Kr atoms were excited by soft x-ray emission from a laser produced plasma, Kr excimer emission centered at 147 nm was observed as well as emission from Kr^<2+> at 157nm.Time resolved data of these emissions show both rise times as fast as that of a plasma initiating laser, indicating the direct ion/excimer production by soft x-ray emission from a plasma. This may be advantageous because the excimer production is not much affected by an electron deexcitation process. Based on a photoionization model, the Kr^<2+> ions are produced by photoionization of Kr 4p electrons. This ion production initiates the excimer production kinetics by ionic channels. Less

我提出了一种混合激发方法作为实现软 X 射线激光器的新方法，其中高强度激光产生的多个带电离子被紧凑放电装置的电力进一步激发。由于 Ar 和高强度相互作用的结果在激光场中，我首次观察到 Ar_2^<**> 在 126 nm 处的发射以及一些高次谐波信号，Ar 准分子强度的聚焦激光强度依赖性与隧道电离理论的预测非常吻合。所谓的因此，我发现Ar准分子的产生是由高强度激光产生的电子引发的，这可能会成为电子束装置产生的电子的替代品。众所周知，电子温度是由高强度激光产生的电子引发的。隧道电离对激光强度、波长和偏振非常敏感，然而，考虑到 Ar 的能量传输，实验数据表明，当线偏振和圆偏振激光束与 Ar 相互作用时，Ar 准分子发射没有差异。从理论上讲，高强度激光中的电子产生等离子体，我发现等离子体的快速传导冷却对于准分子的产生起着重要作用，适当的准分子产生的冷却时间常数比三体复合时间常数快得多。是准分子的主要生产过程。为了模拟放电等离子体发射的X射线与稀有气体(Kr)之间的相互作用，使用使用激光等离子体产生的X射线源作为紧凑型X射线源。当Kr原子被激发时通过激光产生的等离子体的软 X 射线发射，观察到以 147 nm 为中心的 Kr 准分子发射以及 157 nm 处的 Kr^<2+> 发射。这些发射的时间分辨数据显示上升时间与等离子体引发激光器，表明通过等离子体的软x射线发射直接产生离子/准分子。这可能是有利的，因为基于光电离的电子去激发过程对准分子的产生影响不大。在模型中，Kr 2+ 离子是通过Kr 4p 电子的光电离产生的，该离子的产生通过离子通道引发准分子产生动力学。