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Fusion energy: Progress, partnerships, and the path to deployment
Over the past decade, fusion energy has moved decisively from scientific aspiration toward a credible pathway to a new energy technology. Thanks to long-term federal support, we have significantly advanced our fundamental understanding of plasma physics—the behavior of the superheated gases at the heart of fusion devices. This knowledge will enable the creation and control of fusion fuel under conditions required for future power plants. Our progress is exemplified by breakthroughs at the National Ignition Facility and the Joint European Torus.
Yuichi Ogawa, Nobuyuki Inoue, Kunihiko Okano
Fusion Science and Technology | Volume 26 | Number 2 | September 1994 | Pages 168-178
Technical Paper | Fusion Reactor | doi.org/10.13182/FST94-A30340
Articles are hosted by Taylor and Francis Online.
As an intense 14-MeV neutron source, a steady-state subignited tokamak plasma is proposed, where a 60-MW neutral beam is injected to sustain a subignited plasma and to drive a plasma current for steady-state operation. Plasma and device parameters are self-consistently designed, taking into account physical (confinement characteristics, beta limit, current drive efficiency, and so on) and engineering (maximum magnetic field strength, blanket/shield thickness, and others) constraints. The result of a comparison between plasmas with A = 2.8 and A = 4 indicates that a large aspect-ratio device is preferable as a neutron source. A surface-averaged 14-MeV neutron flux of ∼0.6 MW/m2 is achievable with R = 4 to 5 m, A = 4, and Bmax = 10 T and is not so sensitive to the major radius. When the maximum magnetic field strength of toroidal field coils is raised to 13 T, a neutron flux more than 1 MW/m2 is available with a device with R = 4 m. If the plasma performance is advanced and plasmas with an L-mode enhancement factor fL of ∼3 and a Troyon coefficient in beta limit g of ∼5 are attainable, a neutron flux of ∼1.6 MW/m2 is achievable even with a device with R = 4 m and Bmax = 10 T. These devices seem to be very attractive not only as a neutron source but also as a supplementary device of an ignition-oriented International Thermonuclear Experimental Reactor (ITER) device.