Joaquim Loizu Cisquella

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Controlled nuclear fusion could provide our society with a clean, safe, and virtually inexhaustible source of electric power production. The tokamak has proven to be capable of producing large amounts of fusion reactions by confining magnetically the ...

Good magnetic surfaces, as opposed to magnetic islands and chaotic field lines, are generally desirable for stellarators. In previous work, Landreman et al. [Phys. of Plasmas 28, 092505 (2021)] showed that equilibria computed by the Stepped-Pressure Equili ...

We identify the turbulent regimes in the tokamak scrape-off layer as a function of plasma resistivity, electron to ion mass ratio, safety factor, and magnetic shear. We find that two main instabilities drive turbulence in the SOL: Drift Waves, with their r ...

Gyrotrons are essential devices for the development of nuclear fusion, but their design and reliable operation still present numerous challenges. In particular, certain gyrotrons encounter issues related to trapped electron clouds in the magnetron injectio ...

The Super-X Divertor (SXD) is an alternative divertor configuration leveraging total flux expansion at the Outer Strike Point (OSP). While the extended 2-Point Model (2PM) predicts facilitated detachment access and control in the SXD configuration, these a ...

Parallel convection and E × B drifts act together to redistribute heat between the strike-points mechanisms is enhanced near the secondary X-point and is shown to dominate over heat in the low field side snowflake minus (LFS SF−). The cumulative heat conve ...

We demonstrate for the first time that the nonlinear saturation of neoclassical tearing modes (NTMs) can be found directly using a variational principle based on Taylor relaxation, without needing to simulate the intermediate, resistivity-dependent dynamic ...

Recent TCV experiments confirm the predicted formation of an electric potential well, below the magnetic X-point, in configurations with unfavorable

B_t

field direction (ion

\nabla B

drift away from the divertor), that substantially reshapes the typica ...

Single-stage optimization, also known as combined plasma-coil algorithms or direct coil optimization, has recently emerged as a possible method to expedite the design of stellarator devices by including, in a single step, confinement, stability, and engine ...

Electrostatic turbulence, related structures and their effect on particle, heat and toroidal momentum transport are investigated in TORPEX simple magnetized plasmas using high-resolution diagnostics, control parameters, linear fluid models and nonlinear nu ...

Results of a three-dimensional, flux-driven, electrostatic, global, two-fluid turbulence simulation for a five-field period stellarator with an island divertor are presented. The numerical simulation is carried out with the GBS code, recently extended to s ...

The stepped-pressure equilibrium code (SPEC) (Hudson et al., Phys. Plasmas, vol. 19, issue 11, 2012, 112502) is extended to allow the computation of multi-region, relaxed magnetohydrodynamics (MRxMHD) equilibria at prescribed toroidal current profile. Toro ...

Radial neutral density profiles are estimated from measurements of passive Hα emission in the Wendelstein 7-X stellarator. To parametrize the generally three-dimensional distribution with a low number of degrees of freedom, the neutral density is reduced t ...

The implementation of three-dimensional magnetic fields, such as the ones of stellarators, in the GBS code (Ricci et al 2012 Plasma Phys. Control. Fusion54 124047; Giacomin et al 2022 J. Comput. Phys.464 111294) is presented, and simulation results are dis ...

The Stepped Pressure Equilibrium Code (SPEC) (Hudson et al 2012 Phys. Plasmas 19 112502) has been successful in the construction of equilibria in 3D configurations that contain a mixture of flux surfaces, islands and chaotic magnetic field lines. In this m ...

This study considers the self-consistent formation and dynamics of electron clouds interacting with a background neutral gas through elastic and inelastic (ionization) collisions in coaxial geometries similar to gyrotron electron guns. These clouds remain ...

While it is important to design stellarators with high magnetohydrodynamic stability β-limit, it is also crucial to ensure that good magnetic surfaces exist in a large range of β values. As β increases, pressure-driven currents perturb the vacuum magnetic ...

This paper presents the new 2D electrostatic particle -in -cell code FENNECS developed to study the formation of magnetized non -neutral plasmas in geometries with azimuthal symmetry. This code has been developed in the domain of gyrotron electron gun desi ...

The stepped-pressure equilibrium code (SPEC) (Hudson et al 2012 Phys. Plasmas 19, 112 502) is extended to enable free-boundary multi-region relaxed magnetohydrodynamic (MRxMHD) equilibrium calculations. The vacuum field surrounding the plasma inside an arb ...

The location of the plasma sheath edge, where quasineutrality is broken, is rigorously derived by using a kinetic description of the plasma. It is shown that sheaths can exist with arbitrarily small ion velocity at the sheath edge, thus violating the Bohm ...

Joaquim Loizu Cisquella

Chattez avec Graph Search

The role of the sheath in magnetized plasma turbulence and flows

Stellarator optimization for nested magnetic surfaces at finite β and toroidal current

Turbulent regimes in the tokamak scrape-off layer

Electron trapping in gyrotron electron guns: Validation of the FENNECS code with the T-REX experiment

Parallel flows as a key component to interpret Super-X divertor experiments

Parallel convection and E × B drifts in the TCV snowflake divertor and their effects on target heat-fluxes

Direct prediction of saturated neoclassical tearing modes in slab using an equilibrium approach

Experimental verification of X-point potential well formation in unfavorable magnetic field direction

Simplified and Flexible Coils for Stellarators using Single-Stage Optimization

Electrostatic instabilities, turbulence and fast ion interactions in the TORPEX device

Global fluid simulation of plasma turbulence in a stellarator with an island divertor

Computation of multi-region, relaxed magnetohydrodynamic equilibria with prescribed toroidal current profile

Measurements of radial neutral density profiles from Balmer-α emission in Wendelstein 7-X

Global fluid simulation of plasma turbulence in stellarators with the GBS code

On the non-existence of stepped-pressure equilibria far from symmetry

Self-consistent formation and steady-state characterization of trapped high-energy electron clouds in the presence of a neutral gas background

Equilibrium β-limits dependence on bootstrap current in classical stellarators

FENNECS: a novel particle-in-cell code for simulating the formation of magnetized non-neutral plasmas trapped by electrodes of complex geometries

Free-boundary MRxMHD equilibrium calculations using the stepped-pressure equilibrium code

Existence of subsonic plasma sheaths