30-40 MJ high yield diamond ablator designs for a NIF 2.6 MJ laser upgrade*

Achieving ignition [1-3] and high fusion yields with target gain > unity [4-6] in recent National Ignition Facility (NIF) experiments has enabled accessing a new regime of density and pressure in the laboratory that was only previously accessible by nuclear weapons.  This study explores diamond ablator designs for an enhanced NIF laser capability (2.6 MJ), which are projected to produce 10s of MJ of fusion energy. Initial designs are restricted to laser powers of 450 TW, which puts constraints on the target design.  Since a direct hydrodynamic scaling of current experiments would require higher laser power, i.e., Power ~ Scale^2, we adopt a similar design methodology as that used in current NIF implosions whereby reducing the implosion velocity enables greater areal density and increased fuel burn-up fraction by fielding thicker, and in this case also larger, diamond ablators.   

 

[1] H. Abu-Shawareb, (Indirect Drive ICF Collaboration, Phys. Rev. Lett. 129 (2022).

[2] A. L. Kritcher et al., Phys. Rev. E 106, 025201 (2022)

[3] A. Zylstra, et al., Phys. Rev. E 106, 025202 (2022).

[4] H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 132, 065102 (2024)

[5] A. L. Kritcher et al., Phys. Rev. E 109, 025204 (2024)

[6] A. Pak, A. Zylstra et al., Phys. Rev. E 109, 025203 (2024)