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arXiv · 1509.04185

Resilience of quasi-isodynamic stellarators against trapped-particle instabilities

J. H. E. Proll·P. Helander·J. W. Connor·G. G. Plunk
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Abstract

It is shown that in perfectly quasi-isodynamic stellarators, trapped particles with a bounce frequency much higher than the frequency of the instability are stabilizing in the electrostatic and collisionless limit. The collisionless trapped-particle instability is therefore stable as well as the ordinary electron-density-gradient-driven trapped-electron mode. This result follows from the energy balance of electrostatic instabilities and is thus independent of all other details of the magnetic geometry.

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J. H. E. Proll, P. Helander, J. W. Connor, G. G. Plunk. 2015-09-14. Resilience of quasi-isodynamic stellarators against trapped-particle instabilities. https://doi.org/10.1103/physrevlett.108.245002

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