103 citations · 704 across the 25 of their papers we have counts for
5 papers · 1 filter
Resilience of quasi-isodynamic stellarators against trapped-particle instabilities
J. H. E. Proll, P. Helander, J. W. Connor +1
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 elec…
The universal instability in general geometry
P. Helander, G. G. Plunk
The "universal" instability has recently been revived by Landreman, Antonsen and Dorland [1], who showed that it indeed exists in plasma geometries with straight (but sheared) magn…
Impurities in a non-axisymmetric plasma: transport and effect on bootstrap current
Albert Mollén, Matt Landreman, Håkan M. Smith +2
Impurities cause radiation losses and plasma dilution, and in stellarator plasmas the neoclassical ambipolar radial electric field is often unfavorable for avoiding strong impurity…
Magnetic compressibility and ion-temperature-gradient-driven microinstabilities in magnetically confined plasmas
A. Zocco, P. Helander, J. W. Connor
The electromagnetic theory of the strongly driven ion-temperature-gradient (ITG) instability in magnetically confined toroidal plasmas is developed. Stabilizing and destabilizing e…
Electrostatic potential variation on the flux surface and its impact on impurity transport
J. M. García-Regaña, C. D. Beidler, Y. Turkin +5
The particle transport of impurities in magnetically confined plasmas under some conditions does not find, neither quantitatively nor qualitatively, a satisfactory theory-based exp…