Reaching a Burning Plasma and Ignition Using Smaller Capsules/Hohlraums, Higher Radiation Temperatures and Thicker Ablator/Ice on the National Ignition Facility

In indirect-drive implosions, the final core hot spot energy and pressure and hence neutron yield attainable in 1D increases with increasing laser peak power and hence radiation drive temperature at fixed capsule and hohlraum size. We present simple analytic scalings validated by 1D simulations that quantify the improvement in performance and use this to explain existing data and simulation trends. Extrapolating to the 500 TW NIF peak power limit in a low gas-fill 5.4 mm diameter hohlraum based on existing high adiabat implosion data at 400 TW, 1.3 MJ and 1e16 yield, we find that a 2-3e17 yield (0.5 – 0.7 MJ) is plausible using only 1.8 MJ of laser energy. Based on existing data varying DT fuel thickness and dopant areal density, further improvements should be possible by increasing DT fuel areal density, and hence confinement time and yield amplification.