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Nuclear Criticality Safety
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Materials in Nuclear Energy Systems (MiNES 2023)
December 10–14, 2023
New Orleans, LA|New Orleans Marriott
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Fusion Science and Technology
Argonne assists advanced reactor development with award-winning safety software
The development of modern nuclear reactor technologies relies heavily on complex software codes and computer simulations to support the design, construction, and testing of physical hardware systems. These tools allow for rigorous testing of theory and thorough verification of design under various use or transient power scenarios.
Hongda He, J. Q. Dong, Zhixiong He, K. Zhao
Fusion Science and Technology | Volume 70 | Number 1 | July 2016 | Pages 54-61
Technical Paper | doi.org/10.13182/FST15-169
Articles are hosted by Taylor and Francis Online.
The density gradient of fast ions is the main driving force for fishbone instability that in turn results in fast ion loss. It is possible to reduce the instability by eliminating the density gradient of the fast ions by employing dual neutral beam injection (DNBI) in tokamak plasmas. The dispersion relation for the fishbone instability is applied to the case of DNBI with suitable fast ion distribution functions. The results show that the density distribution of fast ions of DNBI can bring about a stable window that is a range of values for the distance between the on-axis beam and the off-axis beam that yields an overall stabilization of the resultant fishbone mode. The width of the stable window increases linearly with the position of the safety factor q = 1 magnetic flux surface increasing. In addition, the width of the stable window becomes wider for a more peaked density profile of fast ions and keeps constant for a peaked enough density profile of fast ions. The growth rates of the fishbone modes dramatically decrease with the intensity ratio of off-axis neutral beam injection (NBI) and on-axis NBI, and the critical beta values of fast ions increase with the intensity ratio increasing. Fishbone modes can be avoided with DNBI, which may be an effective method to prevent fast ion loss resulting from fishbone instabilities.