45 citations · 261 across the 16 of their papers we have counts for
17 papers
A feasibility study for a Doppler Reflectometer System in the JT-60SA tokamak
D. Carralero, T. Happel, T. Estrada +5
In this work we present a study on the viability and practicality of installing a Doppler reflectometer (DR) system in the JT-60SA advanced tokamak. First, we discuss its scientifi…
H-mode transition in the TJ-II stellarator plasmas
T. Estrada, C. Hidalgo
Since the first H-mode transitions were observed in TJ-II plasmas in 2008, an extensive experimental effort has been done aiming a better physics understanding of confinement trans…
Impact of magnetic islands on plasma flow and turbulence in W7-X
T. Estrada, E. Maragkoudakis, D. Carralero +13
The effect of magnetic islands on plasma flow and turbulence has been experimentally investigated in the stellarator W7-X. Magnetic configurations with the 5/5 magnetic island posi…
Radial electric field and density fluctuations measured by Doppler reflectometry during the post-pellet enhanced confinement phase in W7-X
T. Estrada, D. Carralero, T. Windisch +13
Radial profiles of density fluctuations and radial electric field, , have been measured using Doppler reflectometry during the post-pellet enhanced confinement phase achieved,…
On the interaction between the island divertor heat fluxes, the scrape-off layer radial electric field and the edge turbulence in Wendelstein 7-X plasmas
E. Maragkoudakis, D. Carralero, T. Estrada +11
The formation of the radial electric field, in the SOL has been experimentally studied for attached divertor conditions in stellarator W7-X. The main objective of this…
On the role of density fluctuations in the core turbulent transport of Wendelstein 7-X
D. Carralero, T. Estrada, E. Maragkoudakis +19
A recent characterization of core turbulence carried out with a Doppler reflectometer in the optimized stellarator Wendelstein 7-X (W7-X) found that discharges achieving high ion t…
Fast simulations for large aspect ratio stellarators with the neoclassical code KNOSOS
J. L. Velasco, I. Calvo, F. I. Parra +5
In this work, a new version of KNOSOS is presented. KNOSOS is a low-collisionality radially-local, bounce-averaged neoclassical code that is extremely fast, and at the same time, i…
An experimental characterization of core turbulence regimes in Wendelstein 7-X
D. Carralero, T. Estrada, E. Maragkoudakis +14
First results from the optimized helias Wendelstein 7-X stellarator (W7-X) have shown that core transport is no longer mostly neoclassical, as is the case in previous kinds of stel…
Characterization of the radial electric field and edge velocity shear in Wendelstein 7-X
D. Carralero, T. Estrada, T. Windisch +13
In this work we present the first measurements obtained by the V-band Doppler reflectometer during the second operation phase of Wendelstein 7-X to discuss the influence in the vel…
On the interplay between turbulent forces and neoclassical particle losses in Zonal Flow dynamics
R. Gerrú, S. Mulas, U. Losada +5
This study presents the investigation of the connection between radial electric field, gradient of Reynolds stress and Long Range Correlation (LRC), as a proxy for Zonal Flows (ZF)…
On-surface potential and radial electric field variations in electron root stellarator plasmas
J. M. García-Regaña, T. Estrada, I. Calvo +8
In the present work we report recent radial electric field measurements carried out with the Doppler reflectometry system in the TJ-II stellarator. The study focuses on the fact th…
Observation of oscillatory radial electric field relaxation in a helical plasma
J. A. Alonso, E. Sanchez, I. Calvo +13
Measurements of the relaxation of a zonal electrostatic potential perturbation in a non-axisymmetric magnetically confined plasma are presented. A sudden perturbation of the plasma…
Moderation of neoclassical impurity accumulation in high temperature plasmas of helical devices
J. L. Velasco, I. Calvo, S. Satake +16
Achieving impurity and helium ash control is a crucial issue in the path towards fusion-grade magnetic confinement devices, and this is particularly the case of helical reactors, w…
Particle transport after pellet injection in the TJ-II stellarator
J. L. Velasco, K. J. McCarthy, N. Panadero +17
We study radial particle transport in stellarator plasmas using cryogenic pellet injection. By means of perturbative experiments, we estimate the experimental particle flux and com…
The causal impact of magnetic fluctuations in slow and fast L-H transitions at TJ-II
B. Ph. van Milligen, T. Estrada, B. A. Carreras +6
This work focuses on the relationship between L-H (or L-I) transitions and MHD activity in the low magnetic shear TJ-II stellarator. It is shown that the presence of a low order ra…
The role of magnetic islands in modifying long range temporal correlations of density fluctuations and local heat transport
B. Ph. van Milligen, T. Estrada, L. Garcia +7
This work explores the relation between magnetic islands, long range temporal correlations and heat transport. A low order rational surface () was purposely scanned outw…
Spatiotemporal and Wavenumber Resolved Bicoherence at the Low to High Confinement Transition in the TJ-II Stellarator
B. Ph. van Milligen, T. Estrada, C. Hidalgo +2
Plasma turbulence is studied using Doppler reflectometry at the TJ-II stellarator. By scanning the tilt angle of the probing beam, different values of the perpendicular wave number…