Development of a Picosecond X-Ray Spectroscopy System

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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.