Laser and X-Ray Irradiation Diagnostics that have Paved the Path to Significantly Improved ICF Target Performance

Obtaining high performance from direct-drive inertial confinement fusion (ICF) targets requires careful control of the target irradiation. The temporal pulse shape and the on-target irradiation uniformity are of particular concern. A broad arsenal of techniques and diagnostics has been developed for the OMEGA laser1 to ensure that the on-target irradiation meets the requirements. Most of these directly diagnose the laser itself. However, x-rays emitted from the target are also used to confirm that the required irradiation-uniformity levels have been achieved. The improvements to laser uniformity made possible with these diagnostics, combined with improvements to individual-beam uniformity provided by beam-smoothing techniques, have resulted in significantly improved target performance and reduced shot-to-shot variability.