Effects of self-generated magnetic fields on the stagnation phase of cryogenic OMEGA implosions

In this work, the magnitude and evolution of self-generated magnetic fields in an Omega implosion is studied using the deceleration-phase code DEC2D. DEC2D simulates the stagnation-phase of implosions using an Eulerian moving mesh solver and models the growth of the Rayleigh-Taylor instability at the shell hot-spot interface. This instability can generate anti-parallel temperature and density gradients, producing Biermann battery magnetic fields. In order to model these magnetic fields, MHD solvers have been added in DEC2D: this includes advection, resistive diffusion, Nernst, thermal suppression, and the Righi-Leduc term. Maximum magnetic fields of ≈500 MG are estimated, with corresponding Hall parameters of ≈10. These estimates are in agreement with estimates in GORGON. However, we find that these magnetic fields in the Omega implosions occupy very small regions within the hot-spot ( ≈1-10 μm), with the field magnitude being significant only within 10 ps of stagnation, causing marginal increase in yield and ion temperature.