Time resolved heat propagation in a gold crystal by means of picosecond x-ray diffraction

Abstract

Characteristic Cu Kα 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–probe experiment to study the heat propagation in a Au(111) crystal lattice. Changes in the x-ray diffraction pattern in the first 100 ps are clearly observed with about 10 ps resolution. The system allows for detection of temperature changes of 20 °C in the 8–20 ps time frame.