TIME-RESOLVED HEAT PROPAGATION IN A GOLD CRYSTAL BY MEANS OF PICOSECOND X-RAY-DIFFRACTION

Characteristic Cu K alpha x-ray pulses of less than 10 ps duration at 300 Hz repetition rate are generated in a x-ray diode driven by 1.8 ps , 193 nm pulses. Both light and x-ray pulses are utilized in pump-prob e experiment to study the heat propagation in a Au(111) crystal lattic e. Changes in the x-ray diffraction pattern in the first 100 ps are cl early observed with about 10 ps resolution. The system allows for dete ction of temperature changes of 20 degrees C in the 8-20 ps time frame . (C) 1996 American Institute of Physics.