Driving larger NIF implosions with smaller CCR designs

The expected fusion performance of an ICF implosion is strongly dependent on the capsule scale, roughly as the 4$^{\mathrm{th}}$ power. The program at NIF is pursuing several avenues towards driving larger capsules within the constraints of the existing laser system. We present new results for a design with a case-to-capsule ratio (CCR) of \textasciitilde 2.7, significantly smaller than other modern low-gas-fill hohlraum designs which have operated at CCR \textgreater 3. Small CCR increases the coupling efficiency to the capsule, at a cost of more challenging Legendre mode 2 symmetry, which we compensate using wavelength tuning to empirically adjust the cross-beam energy transfer between the inner and outer beams. Results from shock timing, in-flight and stagnation symmetry of gas-filled implosions, and DT layered experiments will be presented.