Exploration of Burning Plasmas in FIRE

The Advanced Reactor Innovation Evaluation Studies (ARIES) have identified the key physics and technical issues that must be resolved before attractive fusion reactors can be designed and built. The Fusion Ignition Research Experiment (FIRE) design study has been undertaken to define the lowest cost facility to address the key burning plasma and advanced tokamak physics issues identified in the ARIES studies. The configuration chosen for FIRE is similar to that of ARIES-AT, a steady-state advanced tokamak reactor based on a high-β and high-bootstrap-current operating regime. The key advanced tokamak features of FIRE are: strong plasma shaping, double-null pumping divertors, low toroidal field ripple (< 0.3%), internal control coils and space for wall stabilization capabilities. The initial burning plasma experimental phase will utilize the Elmy H- Mode regime with Q ≈ 10 sustained under quasi-stationary conditions for ~ 2 plasma current redistribution times (τcr). A longer term goal of FIRE is to explore "steady-state" high-β advanced tokamak regimes with high bootstrap fractions (fBS) ≈ 75% at β N ≈ 4 and moderate fusion gain (Q ≈ 5 to 10) under quasi-steady-state conditions for ≈ 3 τcr. FIRE activities have focused on the physics and engineering assessment of a compact, high-field, cryogenic-copper-coil tokamak with: Ro = 2.14 m, a = 0.595 m, Bt (Ro) = 6 to 10T, Ip = 4.5 to 7.7 MA with a flat top time of 40 to 20 s for 150 MW of fusion power. FIRE will utilize only metal plasma facing components; Be coated tiles for the first wall and W brush divertors to reduce tritium retention as required for fusion reactors. FIRE will be able to test divertor and plasma facing components under reactor relevant power densities since the fusion power density of 6 MWm-3 and neutron wall loading of 2.3 MWm-2 approach those expected in a reactor.