Publications Details
Research Challenges in Magneto-Inertial Fusion
Inertial Confinement Fusion (ICF) is a grand challenge for high-energy-density science. In traditional ICF, alpha heating is achieved by producing T ~ 4 keV hot spot surrounded by a high areal density (ρR ~1 g/cm2) of cold fuel, requiring hot-spot pressures above 400 Gbar. In Magneto-Inertial Fusion (MIF), the pressure and areal density requirements are relaxed by the presence of a magnetic field strong enough to magnetically confine charged particles within a radius smaller than the fuel radius. The key parameter for MIF is thus BR rather than ρR, and for BR >0.5 MG-cm, the magnetic field effectively traps electrons, 1 MeV tritons, and fusion-produced alpha particles for almost arbitrarily small ρR. Consequently, thermal conduction losses are reduced and trapped alpha particles return much of their energy to the burning plasma. Operating at intermediate plasma density and pressure regimes between traditional magnetic confinement fusion and ICF systems, MIF concepts achieve self-heating at pressures of only ~5 Gbar, with GJ-scale yields appearing possible. Ongoing experiments demonstrate good inertial and magnetic confinement, stable implosions, and promising yields, but challenges remain in optimizing preheat, mitigating mix, and understanding fundamental plasma physics and magneto-hydrodynamic behavior in these extreme conditions.