5 papers · 1 filter
Runaway electrons during a coil quench in stellarators
Pavel Aleynikov, Per Helander, HÃ¥kan M Smith
It is shown that avalanches of runaway electrons can arise in stellarators, even if there is no net toroidal current in the plasma or the magnetic-field coils, if the current in th…
Piecewise omnigenous stellarators with zero bootstrap current
Ivan Calvo, Jose Luis Velasco, Per Helander +1
Until now, quasi-isodynamic magnetic fields have been the only known stellarator configurations that, at low collisionality, give small radial neoclassical transport and zero boots…
Quasi-isodynamic stellarators with low turbulence as fusion reactor candidates
Alan G. Goodman, Pavlos Xanthopoulos, Gabriel G. Plunk +7
The stellarator is a type of fusion energy device that - if properly designed - could provide clean, safe, and abundant energy to the grid. To generate this energy, a stellarator m…
Optimised stellarators with a positive radial electric field
Per Helander, Alan G. Goodman, Craig D. Beidler +2
We draw attention to an interesting possibility in the design and operation of stellarator fusion reactors, which has hitherto been considered unrealistic under burning-plasma cond…
Available energy of plasmas with small fluctuations
P. Helander, R. J. J. Mackenbach
The available energy of a plasma is defined as the maximum amount by which the plasma energy can be lowered by volume-preserving rearrangements in phase space, a so-called Gardner…