Brad Lee Holian

Simulating EXAFS patterns of shocked crystals

Extended X‐ray absorption fine structure (EXAFS) measurements on shocked polycrystalline iron have provided further evidence for the shock induced α−e phase transition in iron. However, recent molecular dynamics investigation of this system has suggested the presence of fcc material in the shocked region. In this paper we will investigate the difficulties in simulating EXAFS signals from molecular dynamics data. We will aim to show that in the case of the shock induced α−e transition EXAFS is insensitive to the type of close packing of the product phase.

Picosecond X-ray diffraction studies of shocked crystals

We have used picosecond X-ray diffraction to gain information on the timescale of plastic flow in shock compressed single crystals of silicon (Si) and copper (Cu).