35 citations · 432 across the 26 of their papers we have counts for
26 papers
Analysis of the ECH effect on the EPM/AEs stability in Heliotron J plasma using a Landau closure model
J. Varela, K. Nagasaki, S. Kobayashi +9
The aim of the present study is to analyze the effect of the electron cyclotron heating (ECH) on the linear stability of Alfven Eigenmodes (AE) and energetic particle modes (EPM) t…
MHD study of extreme space weather conditions for exoplanets with Earth-like magnetospheres: On habitability conditions and radio-emission
J. Varela, A. S. Brun, P. Zarka +3
The present study aims at characterizing the habitability conditions of exoplanets with an Earth-like magnetosphere inside the habitable zone of M stars and F stars like tau Boo, c…
Simulation of the TAEs saturation phase in Large Helical Device device: MHD burst
J. Varela, D. A. Spong, Y. Todo +4
The aim of the present study is to analyze the saturation regime of the Toroidal Alfven Eigenmodes (TAE) in the LHD plasma, particularly the MHD burst. The linear and nonlinear evo…
Theoretical study of the Alfven Eigenmode stability in CFETR steady state discharges
J. Varela, J. Huang, D. A. Spong +6
The aim of this study is to analyze the stability of Alfven Eigenmodes (AE) in the China Fusion Engineering Test Reactor (CFETR) plasma for steady state operations. The analysis is…
Theoretical analysis of the saturation phase of the energetic-ion-driven resistive interchange mode
J. Varela, D. A. Spong, L. Garcia +4
The aim of the present study is to analyze the saturation regime of the energetic-ion-driven resistive interchange mode (EIC) in the LHD plasma. A set of non linear simulations are…
Study of the Alfven Eigenmodes stability in CFQS plasma using a Landau closure model
J. Varela, A. Shimizu, D. A. Spong +2
The aim of this study is to analyze the stability of the Alfven eigenmodes (AE) in the Chinese First Quasi-axisymmetric Stellarator (CFQS). The AE stability is calculated using the…
MHD stability of JT-60SA operation scenarios driven by passing energetic particles for a hot Maxwellian model
J. Varela, K. Y. Watanabe, K. Shinohara +5
We analyze the effects of the passing energetic particles on the resistive ballooning modes (RBM) and the energetic particle driven modes in JT-60SA plasma, which leads to the pred…
Effect of the tangential NBI current drive on the stability of pressure and energetic particle driven MHD modes in LHD plasma
J. Varela, W. A. Cooper, K. Nagaoka +5
The aim of the present study is to analyze the stability of the pressure gradient driven modes (PM) and Alfven eigenmodes (AE) in the Large Helical Device (LHD) plasma if the rotat…
Study of Alfven Eigenmodes stability in plasma with multiple NBI driven energetic particle specie
J. Varela, D. A. Spong, L. Garcia +3
The aim of this study is to analyze the destabilization of Alfven Eigenmodes (AE) by multiple energetic particles (EP) species in DIII-D and LHD discharges. We use the reduced MHD…
Analysis of Alfven Eigenmode destabilization in ITER using a Landau closure model
J. Varela, D. A. Spong, L. Garcia
Alfven Eigenmodes (AE) can be destabilized during ITER discharges driven by neutral beam injection (NBI) energetic particles (EP) and alpha particles. The aim of the present study…
Analysis of the MHD stability and energetic particles effects on EIC events in LHD plasma using a Landau-closure model
J. Varela, D. A. Spong, L. Garcia +3
The aim of this study is to perform a theoretical analysis of the magnetohydrodynamic (MHD) stability and energetic particle effects on a LHD equilibria, calculated during a discha…
Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations
J. Varela, D. A. Spong, M. Murakami +4
Alfven Eigenmodes and magneto-hydrodynamic modes are destabilized in DIII-D reverse magnetic shear configurations and may limit the performance of the device. We use the reduced MH…
Effect of the exoplanet magnetic field topology on its magnetospheric radio emission
J. Varela, V. Réville, A. S. Brun +2
The magnetized wind from stars that impact exoplanets should lead to radio emissions. According to the scaling laws derived in the solar system, the radio emission should depend on…
Analysis of Alfven Eigenmode destabilization in DIII-D high poloidal discharges using a Landau closure model
J. Varela, D. A. Spong, L. Garcia +11
Alfven Eigenmodes are destabilized at the DIII-D pedestal during transient beta drops in high poloidal beta discharges with internal transport barriers (ITBs), driven by n=1 extern…
Analysis of Alfven Eigenmodes destabilization by energetic particles in TJ-II using a Landau-closure model
J. Varela, D. Spong, L. Garcia
Alfven Eigenmodes (AE) can be destabilized by energetic particles in neutral beam injection (NBI) heated plasmas through inverse Landau damping and couplings with gap modes in the…
Effects of turbulence, resistivity and boundary conditions on helicoidal flow collimation: consequences for the Von-Kármán-Sodium dynamo experiment
J. Varela, S. Brun, B. Dubrulle +1
We present hydrodynamic and magneto-hydrodynamic simulations of a liquid sodium flow using the compressible MHD code PLUTO to investigate the magnetic field regeneration in the Von…
Analysis of Alfven Eigenmodes destabilization by energetic particles in Large Helical Device using a Landau-closure model
J. Varela, D. A. Spong, L. Garcia
Energetic particle populations in nuclear fusion experiments can destabilize Alfv\' en Eigenmodes through inverse Landau damping and couplings with gap modes in the shear Alfv\' en…
Magnetic turbulence and pressure gradient feedback effect of the mode soft-hard MHD limit in Large Helical Device
J. Varela, K. Y. Watanabe, S. Ohdachi +1
The aim of this study is to analyze the feedback process between the magnetic turbulence and the pressure gradients in LHD inward-shifted configurations as well as its role in the…
Hard MHD limit in sawtooth like activity in LHD
J. Varela, K. Y. Watanabe, S. Ohdachi +1
The optimization of LHD discharges in inward-shifted configurations with sawtooth like activity is an open issue. These relaxation events limit the LHD performance driving a…
The internal disruption as hard MHD limit of 1/2 sawtooth like activity in Large Helical Device
J. Varela, K. Y. Watanabe, S. Ohdachi
LHD inward-shifted configurations are unstable to resistive MHD pressure-gradient-driven modes. Sawtooth like activity was observed during LHD operation. The main drivers are the u…
Internal disruptions and sawtooth like activity in LHD
J. Varela, L. Garcia, S. Ohdachi +2
LHD inward-shifted configurations are unstable to resistive MHD pressure-gradient-driven modes. These modes drive sawtooth like events during LHD operation. In this work, we simula…
Slow modes in the Hermean magnetosphere: effect of the solar wind hydrodynamic parameters and IMF orientation
J. Varela, F. Pantellini, M. Moncuquet
The aim of this study is to simulate the slow mode structures in the Hermean magnetosphere. We use a single fluid MHD model and a multipolar expansion of the Northward displaced He…
Plasma streams in the Hermean dayside magnetosphere: solar wind injection through the reconnection region
J. Varela, F. Pantellini, M. Moncuquet
The aim of this research is to simulate the interaction of the solar wind with the magnetic field of Mercury and to study the particle fluxes between the magnetosheath and the plan…
The effect of interplanetary magnetic field orientation on the solar wind flux impacting Mercury's surface
J. Varela, F. Pantellini, M. Moncuquet
The aim of this paper is to study the plasma flows on the Mercury surface for different interplanetary magnetic field orientations on the day side of the planet. We use a single fl…