Development of a Picosecond X-Ray Spectroscopy System

该项目利用软X射线单色仪和时间- 飞行电子谱仪结合超快 激光产生等离子体X射线源，以创建一个新的设施， 亚皮秒时间分辨率的X射线研究。 此安装程序将 这是同类产品中的第一个，将用于研究动态 使用时间分辨X射线技术在材料中进行加工。 它 也将有可能研究X射线发射的物理学， 亚皮秒激光产生的等离子体在更高的光谱和 时间分辨率比以前更高。 特别是 高强度飞秒激光系统用于创建超 快速X射线源 这是通过将激光脉冲聚焦到 一个固体靶来重复地产生热的、致密的等离子体。 的 等离子体发射不相干的X射线爆发， 超过一皮秒 一个聚光镜将聚焦一部分 将这些X射线转换成成像软X射线单色仪， 图像和能量都选择X射线，产生输出光束 其能量宽度约为电子伏特的十分之一。 的 X射线束用于超快过程的泵浦-探测研究。 可见波长泵浦脉冲将激发固体表面， 用作探针的X射线脉冲。

This project makes use of a soft x-ray monochromator and a time-of- flight electron spectrometer in combination with an ultra fast laser-produced plasma x-ray source to create a novel facility for x-ray studies with sub-picosecond time resolution. This setup will be the first of its kind, and will be used to study dynamic processes in materials using time-resolved x-ray techniques. It will also be possible to study the physics of x-ray emissions from sub-picosecond laser-produced plasmas at higher spectral and temporal resolution than was previously possible. Specifically, a high-intensity femtosecond laser system is used to create an ultra fast x-ray source. This is done by focusing the laser pulses onto a solid target to repetitively create a hot, dense plasma. The plasma emits an incoherent burst of x-rays with time duration less than one picosecond. A collecting optic will focus a portion of these x-rays into an imaging soft x-ray monochromator, which will both image and energy select the x-rays, creating an output beam with an energy width of about one tenth of an electron volt. The x-ray beam is used for pump-probe studies of ultra fast processes. A visible wavelength pump pulse will excite a solid surface, with the x-ray pulse used as a probe.