Fast particle generation and energy transport in laser-solid interactions

The generation of MeV electron and ion beams using lasers with intensities of up to ${10}^{20} {\mathrm{W cm}}^{\mathrm{-2}}$ is reported. Intense ion beams with high energies (up to 40 MeV and to ${\text{3×10}}^{12}$ 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.