Nuclear Fushion | |
Experimental evidence of runaway electron tail generation via localized helical structure in pellet-triggered tokamak disruptions | |
article | |
X.D. Du1  N.W. Eidietis1  E.M. Hollmann2  D. Finkenthal3  L. Stagner1  C. Paz-Soldan1  E.J. Strait1  J.L. Barr1  A. Lvovskiy1  | |
[1] General Atomics;University of California San Diego;Palomar. College | |
关键词: runaway electrons; tokamak disruptions; MHD instabilities; | |
DOI : 10.1088/1741-4326/ac1e5e | |
来源: Institute of Physics Publishing Ltd. | |
【 摘 要 】
A novel detector, using stacked BGO crystals, is developed for runaway electron (REs) studies in the DIII-D tokamak. It is able to resolve fast dynamics of high-energy tail formation of REs with an ultra-high time resolution of ∼1 μ s. As a cost, the detector estimates the 'effective' energy of a given shape of γ-ray spectra and sacrifices the energy resolution. In aid of the new measurement capability, a rapid, inhomogeneous growth of RE tail is observed in detail during a major disruption triggered by an argon pellet. It is found that both the population and energy of a well-confined RE tail significantly oscillate at the early period of the growth. The oscillation phase is locked to a slow rotating magnetohydrodynamic instability, which is briefly destabilized for only ∼1 ms at the early period of the current quench. The oscillation ceases promptly, when the mode disappears. The data suggests that the high-energy RE tail is well-confined and accelerated via a localized helical structure in the plasma core.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
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RO202307170000312ZK.pdf | 2937KB | download |