Time-resolved X-ray diffraction for visualization of atomic motion

Abstract

For ultrafast material analyses, we constructed the time-resolved X-ray diffraction system utilizing ultrashort X-rays from laser produced plasma generated by the 12TW-50fs laser at Nuclear Engineering Research Laboratory. Ultrafast transient changes in laser-irradiated GaAs crystals were observed as X-ray diffraction patterns. A subpeak appears in X-ray diffraction profiles and shifts its position gradually as time goes in the case of 1.3 mJ/mm ^2 laser fluence. Experimental results were compared with numerical analyses to infer the atomic arrangement during the transition.