87 citations · 1.2k across the 60 of their papers we have counts for
8 papers · 1 filter
Radial transport of toroidal angular momentum in tokamaks
Ivan Calvo, Felix I. Parra
The radial flux of toroidal angular momentum is needed to determine tokamak intrinsic rotation profiles. Its computation requires knowledge of the gyrokinetic distribution function…
Less constrained omnigeneous stellarators
Felix I. Parra, Ivan Calvo, Per Helander +1
A stellarator is said to be omnigeneous if all particles have vanishing average radial drifts. In omnigeneous stellarators, particles are perfectly confined in the absence of turbu…
Equivalence of two different approaches to global gyrokinetic simulations
Felix I. Parra, Michael Barnes
A set of flux tube gyrokinetic equations that includes the effect of the spatial variation of the density, temperature and rotation gradients on the turbulence is derived. This new…
Radial penetration of flux surface shaping in tokamaks
Justin Ball, Felix I. Parra
Using analytic calculations, the effects of the edge flux surface shape and the toroidal current profile on the penetration of flux surface shaping are investigated in a tokamak. I…
Intrinsic rotation in tokamaks: theory
Felix I. Parra, Michael Barnes
Self-consistent equations for intrinsic rotation in tokamaks with small poloidal magnetic field compared to the total magnetic field are derived. The model gives the mome…
Flow damping in stellarators close to quasisymmetry
Ivan Calvo, Felix I. Parra, J. L. Velasco +1
Quasisymmetric stellarators are a type of optimized stellarators for which flows are undamped to lowest order in an expansion in the normalized Larmor radius. However, perfect quas…
Optimizing stellarators for large flows
Ivan Calvo, Felix I. Parra, J. Arturo Alonso +1
Plasma flow is damped in stellarators because they are not intrinsically ambipolar, unlike tokamaks, in which the flux-surface averaged radial electric current vanishes for any val…
When omnigeneity fails
Felix I. Parra, Ivan Calvo, Jose Luis Velasco +1
A generic non-symmetric magnetic field does not confine magnetized charged particles for long times due to secular magnetic drifts. Stellarator magnetic fields should be omnigeneou…