Impact of different electron thermal conductivity models on the performance of cryogenic implosions

The electron thermal conduction strongly affects the hot-spot formation and the hydrodynamic instability growth in inertial confinement fusion implosions. A harmonic-mean flux-limited conductivity model has been widely used in implosion simulations. In this paper, using the high foot implosion N140520 as an example, we have performed a series of one-dimensional (1D) no-alpha simulations to quantify the impact of different conductivity models including the Spitzer-Harm model, the Lee-More model, and the recently proposed coupled Gericke-Murillo-Schlanges model [Ma et al., Phys. Rev. Lett. 122, 015001 (2019)] with the flux limiter f(e) ranging from 0.03 to 0.15 on the performance of cryogenic implosions. It is shown that varying f(e) has a bigger impact on the performance than changing conductivity models. Therefore, we have only performed two-dimensional (2D) no-alpha simulations using the Lee-More model with different flux limiters f e L M to quantify the effect of the electron thermal conduction on the performance, with single-mode velocity perturbations with different mode numbers L seeded on the inner shell surface near the peak implosion velocity. We find that in both the 1D implosions and the 2D implosions with the same L, increasing f(e) leads to more hot-spot mass and lower hot-spot-averaged ion temperature, resulting in approximately constant hot-spot internal energy. In addition, the no-alpha yield Y n alpha is dominated by the neutron-averaged ion temperature T-n in these two cases. Increasing f e L M from 0.0368 to 0.184 reduces T-n by similar to 15% in 1D and by & SIM;20% for the 2D implosions with the same L, both leading to a similar to 20% reduction in Y-n alpha.& nbsp;Published under an exclusive license by AIP Publishing.