Author/Authors :
Dufresne، نويسنده , , Eric M. and Adams، نويسنده , , Bernhard and Chollet، نويسنده , , Matthieu and Harder، نويسنده , , Ross and Li، نويسنده , , Yuelin and Wen، نويسنده , , Haidan and Leake، نويسنده , , Steven J. and Beitra، نويسنده , , Loren and Huang، نويسنده , , Xiaojing and Robinson، نويسنده , , Ian K.، نويسنده ,
Abstract :
When a short-pulse laser beam is absorbed in a crystal, the heat or large electric field can induce time-dependent strain waves which propagate in the material at the speed of sound. At a synchrotron, the repetition rate of the X-ray source (MHz) and the laser (kHz) is often mismatched by several orders of magnitude leading to a very inefficient use of the X-ray probe beam. In this paper, we will show how one can synchronize a femtosecond 88 MHz Ti:Sapphire laser to the APS running at the same repetition rate in 324-bunch mode. This efficient use of the X-rays enabled us to measure coherent diffraction patterns from nanoparticle of ZnO as a function of the Bragg angle and time delay between the laser-pump and X-ray probe beams. Significant time-dependent strain can be created with a few nanoJoule per pulse when the nanoparticle is centered in a tight laser focus of a few microns.
