Subpicosecond time-resolved X-ray diffraction with a laser plasma X-ray source

A source of very short and bright X-ray pulses for time-resolved laser pump X-ray probe experiments is developed. The response of a Langmuir-Blodgett film of Cd arachidate to the heating by a laser pulse is studied and the Bragg reflection for different delays between X-rays and heating pulse is observed. A strong decrease of the X-ray diffracted intensity in a time scale from few hundreds of femtoseconds to few tens of picoseconds depending on the energy of the heating pulse. The experiment demonstrated that ultrafast dynamics can be studied in the X-ray regime with a laser-plasma x-ray source.