Extended x-ray absorption fine-structure experiments with a laser-imploded target as a radiation source

The feasibility of using extended x-ray absorption fine structure (EXAFS) for characterizing metals shocked to megabar (1 bar = 0.1 MPa) pressures by a laser has been studied. High-contrast K-edge modulations for an unshocked Ti-foil absorber were obtained with a laser-imploded spherical target as a source. The high intensity and relative smoothness of the source spectrum enable us to work with thick Ti foils, which increases the relative modulation in the measured signal. Using a semiempirical model to describe the shock-compressed foil, we show that, because of the rise in Debye temperature with density, the compression extends the temperature range at which EXAFS modulations can be observed. (C) 2003 Optical Society of America.