Experiments and multiscale simulations of|[nbsp]|laser propagation through ignition-scale|[nbsp]|plasmas

With the next generation of high-power laser facilities for inertial fusion coming online1,2, ensuring laser beam propagation through centimetre-scale plasmas is a key physics issue for reaching ignition. Existing experimental results3,4,5 including the most recent one6 are limited to small laser spots, low-interaction laser beam energies and small plasma volumes of 1–2 mm. Here, we demonstrate the propagation of an intense, high-energy, ignition-size laser beam through fusion-size plasmas on the National Ignition Facility (NIF) and find the experimental measurements to agree with full-scale modelling. Previous attempts to apply computer modelling as a predictive capability have been limited by the inherently multiscale description of the full laser–plasma interaction processes7,8,9,10,11. The findings of this study validate supercomputer modelling as an essential tool for the design of future ignition experiments.