Design of a direct-drive experimental platform for exploring the effects of heterogeneous mix on fusion burn*

      Recent experiments to quantify the impact of heterogeneous mix on thermonuclear burn have demonstrated that assumptions of a single temperature in the mix region and a single scale length describing mix morphology may not be adequate for a heterogenous mix burn model.  The experiments were performed at the NIF and utilized indirectly driven plastic capsules filled with a deuterated plastic foam of controlled coarseness, with tritium gas filling the voids in the foam.  A new approach utilizing larger (~2X diameter) directly driven capsules with higher laser drive coupling will enable much higher (~100X to 1000X) thermonuclear yields in a much larger (~100X) burn volume.  The higher yields will enable more constraining diagnostics including burn history measurements, neutron imaging, and spectroscopy (using dopants).  The new, direct-drive capsules will be filled with a recently developed 3D printed lattice – opening a wide range of possible experiments, including specified location of a deuterated lattice, controlled density and coarseness of the lattice, and structures imprinted in the lattice.  The proposed direct-drive platform (the “Bosque campaign”) will be compared with the previous indirect-drive platform (the “Marble campaign”).