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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Fusion Science and Technology
August 2025
Latest News
DOE fast tracks test reactor projects: What to know
The Department of Energy today named 10 companies that want to get a test reactor critical within the next year using the DOE’s offer to authorize test reactors outside of national laboratories. As first outlined in one of the four executive orders on nuclear energy released by President Trump on May 23 and in the request for applications for the Reactor Pilot Program released June 18, the companies must use their own money and sites—and DOE authorization—to get reactors operating. What they won’t need is a Nuclear Regulatory Commission license.
Junichi Miyazawa, Suguru Masuzaki, Hiroshi Yamada, Ryuichi Sakamoto, Byron Jay Peterson, Mamoru Shoji, Nobuyoshi Ohyabu, Akio Komori, Osamu Motojima, LHD Experimental Group, Peter Grigull, Yuehe Feng, Kent McCormick, Francesco Sardei, Yuri Igitkhanov, W7-AS Team
Fusion Science and Technology | Volume 50 | Number 2 | August 2006 | Pages 192-200
Technical Paper | Stellarators | doi.org/10.13182/FST06-A1235
Articles are hosted by Taylor and Francis Online.
Self-sustained detachment, named the Serpens mode (Self-regulated plasma edge 'neath the last closed flux surface), has been observed in the Large Helical Device (LHD), which is equipped with an intrinsic open helical divertor, in spite of the low divertor neutral pressure of order 10-3 Pa. Other states of detachment are also observed; one is transient partial detachment, observed only in the gas puff port during massive gas puffing, and another is complete detachment, which takes place when the hot plasma boundary shrinks below the last closed flux surface. The Serpens mode is categorized as a subset of complete detachment, but with large fluctuations in the divertor flux and H signal, which result from a rotating radiation belt called the serpent. In this paper, these are compared with experimental observations of partial detachment and multifaceted asymmetric radiation from the edge (Marfe) in a modular stellarator, Wendelstein 7-AS (W7-AS). There are many similarities between transient partial detachment in LHD and partial detachment in W7-AS and, especially, between the Serpens mode in LHD and Marfe in W7-AS.
