X-ray diffraction and continuum measurements in silicon crystals shocked below the elastic limit

The shock wave response of silicon, compressed along [100] and [111], was examined at both the lattice and continuum scales. Peak stresses were below the Hugoniot elastic limit and ranged between 2.8 and 6.9 GPa. X-ray diffraction measurements provided the interplaner spacing changes along the shock loading direction. The continuum response was determined by using laser interferometry to measure the rear surface velocity histories. In contrast to earlier results, both the lattice and continuum results were consistent with the known nonlinear elastic constants of silicon. Additionally, the diffracted intensity in the shocked state was considerably larger than the intensity in the ambient state. (c) 2007 American Institute of Physics.