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Organized to promote the advancement of knowledge in the use of nuclear science and technologies in the aerospace application. Specialized nuclear-based technologies and applications are needed to advance the state-of-the-art in aerospace design, engineering and operations to explore planetary bodies in our solar system and beyond, plus enhance the safety of air travel, especially high speed air travel. Areas of interest will include but are not limited to the creation of nuclear-based power and propulsion systems, multifunctional materials to protect humans and electronic components from atmospheric, space, and nuclear power system radiation, human factor strategies for the safety and reliable operation of nuclear power and propulsion plants by non-specialized personnel and more.
2020 ANS Virtual Winter Meeting
November 15–19, 2020
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Fusion Science and Technology
UWC 2020: A call for transformational change
Bowing to current COVID-19 realities but buoyed by the success of June’s virtual Annual Meeting, ANS event planners returned to the virtual realm for this year’s Utility Working Conference. Originally scheduled for August 9–12 at Marco Island, Fla., the condensed event was held Wednesday, August 11, wherever registrants’ computer devices happened to be located.
In addition to 26 educational sessions and workshops, UWC 2020 featured an opening plenary session titled “Achieving Transformational Change: A leadership discussion,” moderated by Bob Coward, MPR Associates principal officer and ANS past president (2017–2018). Plenary panelists included representatives from three utilities—Arizona Public Service (APS), Exelon, and Xcel Energy—plus the Institute of Nuclear Power Operations (INPO) and the Nuclear Regulatory Commission.
T. Sehmer, K. Lackner, E. Strumberger, E. Fable, O. Kardaun, P. McCarthy, ASDEX Upgrade Team
Fusion Science and Technology | Volume 70 | Number 1 | July 2016 | Pages 73-82
Technical Paper | dx.doi.org/10.13182/FST15-175
Articles are hosted by Taylor and Francis Online.
Modern tokamaks, operating with elongated plasmas, are unstable against vertical displacement. In the presence of conducting walls, this instability assumes the characteristics of a resistive wall mode (RWM), amenable to feedback stabilization. On ASDEX Upgrade (AUG), estimates of the growth rates, entering into the definition of safe operating regimes and into feedback parameter settings, were so far based on a rigid displacement (RD) model. However, for highly triangular plasmas this model was found to predict growth rates that were too small. A code package originally developed for general ideal magnetohydrodynamic (MHD) RWMs (NEMEC/CAS3D/STARWALL) and also capable of handling three-dimensional passive stabilizing loops (PSLs) was therefore applied to the n = 0 case for a large data sample of possible AUG equilibria. The comparison with the previously used rigid vertical displacement model showed that the latter gives a consistently lower limit to the growth rates for typical AUG parameters. A statistical analysis of the RD results brings out the stabilizing effect of triangularity. This stabilizing effect disappears, however, if generalized displacements are taken into account, like in the full MHD resistive wall model. The mode acquires a strong m = 2 component, which allows it also to elude partly the stabilization by the PSL. At low elongation, large triangularity produces even significant additional destabilization, with the mode predominantly m = 2, confined to the outer plasma layers, like predicted in references [see Rosen et al., Phys. Fluids, 18, 482 (1975) and Becker and Lackner, Proc. 6th Int. Conf. Plasma Physics and Controlled Nuclear Fusion Research, Vol. II, p. 401 (1977)]. These results explain the tendencies observed in AUG and will be taken into account in future analyses.