High-power 1 kHz laser-plasma x-ray source for ultrafast x-ray absorption near-edge spectroscopy in the keV range

摘要

A high average power broadband x-ray source is developed in the multi-keV range, based on the thermal emission of plasmas produced with a 1 kHz fs laser focused on high Z element target. This compact ultrafast x-ray source is used to measure the x-ray absorption near-edge spectroscopy of aluminum K-edge (1.559 keV) with noise lower than 1% of the absorption edge when accumulating laser shots over a few tens of seconds. That demonstrates its suitability to study atomic and electronic structures of matter during ultrafast phase transitions among solid, liquid, or higher energy density states.