Oxford Centre for High Energy Density Science (OxCHEDS)

Abstract:

The generation of MeV electron and ion beams using lasers with intensities of up to 1020 W cm-2 is reported. Intense ion beams with high energies (up to 40 MeV and to 3 × 1012 protons >5 MeV) are observed. The properties of these particle beams were measured in considerable detail and the results are compared to current theoretical explanations for their generation. © 2001 American Institute of Physics.

Abstract:

Pump-probe time-resolved x-ray diffraction of allowed and nearly forbidden reflections in InSb is used to follow the propagation of a coherent acoustic pulse generated by ultrafast laser excitation. The surface and bulk components of the strain could be simultaneously measured due to the large x-ray penetration depth. Comparison of the experimental data with dynamical diffraction simulations suggests that the conventional model for impulsively generated strain underestimates the partitioning of energy into coherent modes.