Exploiting Magnetized Transport Effects to Flush Ash from Magneto-inertial Fusion Reactions
Ian Ochs, Princeton University
One of the large motivations behind the development of magneto-inertial fusion, in which a magnetized plasma is rapidly compressed, is to trap the hot fusion products (ash), thus increasing the fraction of fusion energy used to sustain the reaction. Once the ash thermalizes, however, it is no longer favorable to keep it in the plasma, yet the same magnetic fields that advantageously trapped the hot ash now deleteriously confine the cold ash. Fortunately, magnetized inertial fusion experiments are approaching regimes where the radial transport is dominated by collisions between magnetized ions, providing an opportunity to exploit effects usually associated with steady-state magnetic fusion. In particular, the low-density hot-spot characteristic of magnetized liner inertial fusion (MagLIF) results in diamagnetic and Nernst frictions, which can demix thermalized ash from fuel, accelerating the fusion reaction. A simple diffusion and fusion model shows that increases in the fusion energy yield on the order of 10 percent are in fact possible.
Abstract Author(s): Ian E. Ochs, Nathaniel J. Fisch