Characterizing Shrapnel and Debris Produced in High Power Laser Experiments

As large laser facilities increase in beam energy and target size, the propensity to produce shrapnel and debris that may impact target-facing optics lifetimes also increases. We present techniques and results using silica aerogel and thin glass plates to characterize the number, velocity, size, and spatial distribution of shrapnel and mass distribution of debris. We have conducted experiments on the HELEN laser to develop these techniques and provide data to support computer modeling of shrapnel and debris generation. We have begun to measure shrapnel and debris generation on Omega and are evolving plans to make similar measurements on NIF. These techniques appear viable for measuring shrapnel and debris with sufficient resolution to quantify their asymmetric deposition within the target chamber. These passive measurements can confirm improved target designs that reduce target shrapnel and debris effects and therefore aid in extending optics lifetime. Ultimately, these data support the most efficient use of optics in executing experimental campaigns on large laser facilities.