Integrated radiation-magnetohydrodynamic simulations of magnetized burning plasmas—Magnetizing ignition-class designs

Motivated by breakthroughs in inertial confinement fusion (ICF), first achieving ignition conditions in National Ignition Facility (NIF) shot N210808 and then laser energy breakeven in N221204 [H. Abu-Shawareb et al., Phys. Rev. Lett. 129, 075001 (2022); H. Abu-Shawareb et al., Phys. Rev. Lett. 132, 065102 (2024)], modeling efforts investigate the effect of imposed magnetic fields on integrated hohlraum simulations of igniting systems. Previous NIF experiments have shown fusion yield and hot-spot temperature to increase in magnetized, gas-filled capsules [J. D. Moody et al., Phys. Rev. Lett. 129, 195002 (2022)]. We use the 2D radiation-magnetohydrodynamics code Lasnex [G. B. Zimmerman and W. L. Kruer, Plasma Phys. Controlled Fusion 2, 51 (1975)] with a Livermore ICF common model [D. J. Strozzi et al., Phys. Plasmas 31, 092703 (2024)]. Simulations closely reproduce unmagnetized experimental data. Investigated here is the effect of imposed axial fields of up to 100 T on the fusion output of high-performing ICF shots, specifically the record BigFoot shot N180128, and HYBRID-E shots N210808 and N221204. The dominant effect is an increase in hot-spot temperature through suppression of cross field electron heat flow, with secondary enhancement from modified alpha-particle energy deposition at sufficiently high compressed field strength. Electron heat flow perpendicular to the field is suppressed, and alpha trajectories become gyro-orbits [L. J. Perkins et al., Phys. Plasmas 24, 062708 (2017)]. In addition, we investigate the impact of applied magnetic fields to future NIF designs, specifically an example Enhanced Yield Capability design with 3 MJ of laser energy and a high-ρR, low implosion velocity Pushered-Single-Shell design. In conclusion, magnetization with field strengths of 5–75 T is found to increase the burn-averaged ion temperature by 50% and the neutron yield by 2–12×. Specifically, we see yield enhancement of 2× with a 5–10 T applied magnetic field for N221204, while a 65 T field on N210808 with drive symmetrization gives an 8× increase in yield.