Fusion Ignition Research Experiment (FIRE)

Experiments are needed to test and extend present understanding of confinement, macroscopic stability, alpha-driven instabilities, and particle/power exhaust in plasmas dominated by alpha heating. A design study of a Fusion Ignition Research Experiment (FIRE) is underway to assess near term opportunities for producing and studying fusion dominated plasmas in the laboratory. The emphasis is on understanding the behavior of fusion plasmas dominated by alpha heating (Q ≥ 5) that are sustained for a duration comparable to the characteristic plasma time scales (≥ 20 τ_E and ~ 1.5 τ_skin, where τ_skin is the time for the plasma current profile to redistribute at fixed current). These requirements can be satisfied with BeCu/OFHC toroidal field coils and OFHC poloidal coils that are pre-cooled to 77 °K prior to the pulse. The plasma facing components will have tungsten divertor plates and Be first wall tiles. No graphite is allowed inside the vacuum vessel due to tritium retention issues. The mission of FIRE is to attain, explore, understand and optimize alpha-dominated plasmas to provide knowledge for the design of attractive magnetic fusion energy systems. The programmatic strategy is to access the alpha-heating-dominated regime with confidence using the present advanced tokamak data base (e.g., Elmy-H-mode, ≤ 0.75 Greenwald density) while maintaining the flexibility for accessing and exploring other advanced tokamak modes (e. g., reversed shear, pellet enhanced performance) at lower magnetic fields and fusion power for longer durations in later stages of the experimental program. A major constraint is to develop a design concept that could meet these physics objectives with a construction cost in the range of $1B.