Utilizing Two Photon Polymerization 3D Printing for Producing ICF Targets and Studying Imprint Mitigation*

Recent advances in Two Photon Polymerization (2PP) technology have enabled the ability to design and print targets approaching the scale and precision required for inertial confinement fusion (ICF) experiments. We present the iterative process of producing complex planar targets with low density foam structures and translating these towards spherical targets to be shot on the OMEGA and EP lasers at the Laboratory for Laser Energetics. The foam structure was developed for imprint mitigation, relevant to direct-drive ICF. Several iterations of foam structure led to the development of full, single-print spherical and planar targets with foam and solid density material. Measurements utilizing x-ray backlit radiography conclusively show the foam significantly mitigated laser imprint for targets of similar mass. Previous 2PP efforts have encountered difficulties with stitching print elements together to make larger targets while maintaining high resolution. We present target development work that has been done to address and fix the source of these issues.