Ultrafast observation of temperature in laser-shocked Al and Zr*

Laser shock makes a material dense and hot, but how hot would it be? In this abstract, we present our study on the temperature evolution of laser-shocked Al-Zr metal film composite at a time delay of 1 to 75 nanoseconds. The experiments were conducted at the Matter at Extreme Condition station at LCLS, SLAC National Laboratory. Short-pulse lasers with the energy of 2.5, 25, and 30 mJ were applied to shock the sample. Duration of the drive laser was 130 ps while X-ray duration was 130 fs, which allows observation of lattice constant down to nanosecond time resolution. We constrained the temperature evolution of Al from X-ray diffraction-determined thermal expansion and simulated temperature profile by heat conduction models. We found significant heating of both Al (up to 900 K) and Zr (up to 1750 K) after shock release. In comparison, a theoretical model accounting for the dissipation from the ordinary strength effect would underestimate the temperature increase by 220 K for Al and 1000 K for Zr. We will present the results of our observations and models and discuss the implications for shock experiments and some geological settings where shock wave occurs.