X-ray diffraction measurements in shock compressed magnesium doped LiF crystals.

X-ray diffraction measurements, utilizing multiple and single diffraction methods, were used to examine lattice compression of magnesium doped (approximately 100 ppm) LiF single crystals shocked along the [100] direction. Unlike ultrapure LiF crystals, examined in previous x-ray diffraction studies, magnesium doped crystals display large elastic wave amplitudes under shock wave compression. Analysis of multiple diffraction data from the (200) and (202) planes and single diffraction data from the (200) planes showed that the crystal lattice for doped crystals was compressed isotropically in the peak state, similar to that observed for ultrapure crystals. This agreement demonstrates that the large elastic wave amplitude and subsequent stress relaxation observed in wave propagation measurements for the doped LiF crystals are a transient phenomenon and do not appear to affect the lattice compression in the final state. Implications of this finding are discussed. [ABSTRACT FROM AUTHOR]