Experimental study on the dynamic compression of materials at XGIII facility by laser proton photography

Abstract

A new method for material dynamic density measurement based on proton photography is developed at XGIII facility. The protons produced by the picosecond laser of XGIII was used as the proton source to diagnose the density distribution of lattice foam under the compression of the nanosecond beam of XGIII. The density of lattice foam was calculated from the photographic results using Monte Carlo simulation method. Benefitting fromn this newly developed method, the images of the compressed lattice foam and the shock front at 5.2 ns is obtained successfully. The density distribution of the lattice foam was obtained from the images and the density of lattice foam increases about 20 times at the shock front due to the compression of the shock. The velocity of shock wave in lattice foam is also given, about 40 km/s. The density and spatial resolution of the method are further calibrated by using diamond step objects, and experimental results show that they are better than 4% and 12 <i>μ</i>m, respectively. In order to further improve the density and spatial resolution of the proton photography at XGIII facility, a new radiogrphy method utilizing quasimonoenergetic proton beams obtained from an energy selector is proposed in this paper, and the resolution of this method is simulated by Monte Carlo program. The simulation results show that the relative density resolution can be improved to more than 1%. Through the above experimental and the simulation results, we demonstrated that diagnostic capability has been established for fast process (nanosecond scale), high pressure (nearly 100 GPa) conditions at XGIII facility.