Measurements of sound velocity of laser-irradiated iron foils relevant to Earth core condition

We present a novel scheme to measure sound velocity of shock-compressed iron of geophysical interest. The sound velocity of laser-irradiated iron foils was obtained with side-on X-ray radiograph technique from measured rarefaction wave velocity of shocked iron. Iron foils were irradiated with a two-stepped square laser pulse to reach Earth's core condition by double compression. The experimental parameters of temperature and pressure were very close to the Earth's core condition.