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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.
M. Yamada, N. Pomphrey, A. Morita, Y. Ono, M. Katsurai
Fusion Science and Technology | Volume 27 | Number 3 | April 1995 | Pages 161-168
Overview Paper | doi.org/10.13182/FST95-A11947061
Articles are hosted by Taylor and Francis Online.
We investigate experimentally and theoretically the global MHD characteristics of an ultra-low aspect ratio tokamak (ULART). Since the ULART requires a substantially smaller toroidal field current, Itf, than conventional tokamaks, it has important reactor advantages. By fully utilizing the TS-3 merging spheromak facility with a slender center conductor, we have carried out an experimental study of the ultra-low aspect ratio tokamak with aspect ratio reaching as low as 1.05. The ULART is found to be similar to the spheromak in its strong paramagnetism and magnetic helical pitch. In this extreme limit, we investigate the transition of the spheromak (qa = 0, Itf = 0) to a ULART plasma (qa = 5–20, Itf < Ip). It is observed that a small current at the center conductor can significantly improve the overall stability of the formed plasmas by effectively stabilizing the tilt mode. We identify a threshold of Itf << Ip with qcyl(a) << 1 for global tilt/shift modes. This initial observation is in agreement with a global MHD theory.
