High Power Impulse Magnetron Sputtering Based Ablator Development for Laser Fusion Applications

There is an increasing demand for thin- and thick-walled, gas impermeable metal capsules for High Energy Density applications. Gas impermeable capsules are presently fabricated using Direct Current Magnetron Sputtering (DCMS) with low success rate. Previous research indicates gas impermeability has a strong positive correlation with film density because higher thin film densities increase the likelihood of coatings being gas impermeable. DCMS coatings are not dense enough to meet the gas permeability requirement. High Power Impulse Magnetron Sputtering (HiPIMS) is a promising magnetron sputtering technique that is capable of depositing highly dense coatings with stronger adhesion to the substrate compared to DCMS. This work investigates the use of HiPIMS to deposit gas impermeable ablator coatings for laser fusion applications. Metrology results including gas permeability tests like Kr leak tests on metal coatings deposited using HiPIMS are presented. Additionally, DCMS-HiPIMS hybrid techniques to improve the gas permeability are also explored.