25 citations · 46 across the 9 of their papers we have counts for
9 papers
Modification of ion-temperature-gradient turbulence by impurities in stellarator plasmas
Ivan Calvo, Felix I. Parra, Hanne Thienpondt +1
Recent nonlinear gyrokinetic simulations have shown that impurities can strongly modify the turbulent heat flux in stellarator plasmas. Here, the ion-temperature-gradient (ITG) dis…
First experimental observation of zonal flows in the optimized stellarator Wendelstein 7-X
D. Carralero, T. Estrada, J. M. García-Regaña +10
In this work, we present the first experimental evidence of the presence of zonal flow (ZF) structures in the optimized stellarator Wendelstein 7-X. Using an assortment of diagnost…
Piecewise omnigenous stellarators
J. L. Velasco, I. Calvo, F. J. Escoto +3
In omnigeneous magnetic fields, charged particles are perfectly confined in the absence of collisions and turbulence. For this reason, the magnetic configuration is optimized to be…
Influence of the density gradient on turbulent heat transport at ion-scales: an inter-machine study with the gyrokinetic code stella
H Thienpondt, JM García-Regaña, I Calvo +2
Efficient control of turbulent heat transport is crucial for magnetic confinement fusion reactors. This work discusses the complex interplay between density gradients and micro-ins…
Reduced turbulent transport in the quasi-isodynamic stellarator configuration CIEMAT-QI4
J. M. García-Regaña, I. Calvo, E. Sánchez +3
CIEMAT-QI4 is a quasi-isodynamic stellarator configuration that simultaneously features very good fast-ion confinement in a broad range of values, low neoclassical transport an…
Optimisation of Gyrokinetic Microstability Using Adjoint Methods
Georgia Acton, Michael Barnes, Sarah Newton +1
Microinstabilities drive turbulent fluctuations in inhomogeneous, magnetized plasmas. In the context of magnetic confinement fusion devices, this leads to an enhanced transport of…
Reduction or enhancement of stellarator turbulence by impurities
J. M. García-Regaña, I. Calvo, F. I. Parra +1
A systematic study of the impact of impurities on the turbulent heat fluxes is presented for the stellarator Wendelstein 7-X (W7-X) and, for comparison, the Large Helical Device an…
Prevention of core particle depletion in stellarators by turbulence
H. Thienpondt, J. M. García-Regaña, I. Calvo +11
In reactor-relevant plasmas, neoclassical transport drives an outward particle flux in the core of large stellarators and predicts strongly hollow density profiles. However, this t…
Turbulent transport of impurities in 3D devices
J. M. García-Regaña, M. Barnes, I. Calvo +5
A large diffusive turbulent contribution to the radial impurity transport in Wendelstein 7-X (W7-X) plasmas has been experimentally inferred during the first campaigns and numerica…