Controllable production of deuterated polymer beads for ICF

Deuterated polymer beads with specifications on their size and structure are needed for preparing the targets in the inertial confined fusion experiments. Driven by the need to fabricate these beads meeting physical design, the coflow microfluidic device composed of glass round capillaries were fabricated. The formation mechanism of the droplets of the polymer solution (O droplets), the vacuole formation in the polymer beads and the size relationship between the O droplets and the resulting polymer beads were also investigated. The diameter of the O droplets can be controlled by designing microfluidic device with appropriate capillaries and tuning the flow rate of the polymer solution and aqueous solution. Residual solvent in polymer beads was reduced by optimizing the solidifying and drying process, leading to the decrease of the vacuoles. The size relationship between the initial O droplets and the resulting beads was revealed and confirmed. Consequently, monodisperse polymer beads such as ∼480 μm and ∼700 μm poly (α-methylstyrene), ∼700 μm polystyrene and ∼800 μm deuterated polystyrene beads meeting physical design were successfully prepared, which can be used to prepare the target in the inertial confined fusion experiments. It demonstrated the technical feasibility of controlling the bead size, providing a promising approach to fabricate the polymer beads meeting size requirement.