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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.
Hiroshi Tamai, Shinichi Ishida, Gen-Ichi Kurita, Hiroshi Shirai, Katsuhiko Tsuchiya, Shinji Sakurai, Makoto Matsukawa, Akira Sakasai
Fusion Science and Technology | Volume 45 | Number 4 | June 2004 | Pages 521-528
Technical Paper | doi.org/10.13182/FST04-A527
Articles are hosted by Taylor and Francis Online.
A 1.5-dimensional time-dependent transport analysis has been carried out to investigate steady-state operation scenarios with a central current hole by off-axis current drive schemes consistent with a high bootstrap current fraction for the JT-60SC large superconducting tokamak. A steady-state operation scenario with HHy2 = 1.4 and N = 3.7 has been obtained at Ip = 1.5 MA, Bt = 2 T, and q95 = 5, where noninductive currents are developed during the discharge to form a current hole with beam-driven currents by tangential off-axis beams in combination with bootstrap currents by additional on-axis perpendicular beams. The bootstrap fraction increases up to ~75% of the plasma current, and the current hole region is enlarged up to ~30% of the minor radius at 35 s from the discharge initiation. The current hole is confirmed to be sustained afterward for a long duration of 60 s. The present transport simulation shows that heating equipment designed for JT-60SC is capable of forming and sustaining the current hole only by using off-axis beam-driven currents and bootstrap currents. The stability analysis shows that the beta limit with the conducting wall can be ~N = 4.5, which is substantially above the no-wall ideal magnetohydrodynamic limit.