Publications de Olivier Sauter

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A new understanding of edge localized modes (ELMs) in tokamak discharges is emerging (Snyder P B et al 2002 Phys. Plasmas 9 2037), in which the ELM is an essentially ideal magnetohydrodynamic (MHD) instability and the ELM severity is determined by the radial width of the linearly unstable MHD kink modes. A detailed, comparative study of the penetration into the core of the respective linear instabilities in a standard DIII-D ELMing, high confinement mode (H-mode) discharge, with that for two relatively high

The European Integrated Modelling effort (EU-IM) provides the European Transport Simulator (ETS) [1] which was designed to simulate arbitrary tokamak plasma discharges. Two new 1D Fokker-Planck solvers have recently been implemented within ETS: StixRedist ...

The plasma design point during stationary phase operation of EU-DEMO has been described extensively in the past, and the assumptions employed for its definition have been supported by various investigations. However, a stationary snapshot is by far not suf ...

In the Tokamak a Configuration Variable (TCV), the central electron temperature obtained in discharges with counter (CNTR) electron cyclotron current drive (ECCD) is larger than with CO-ECCD or electron cyclotron resonance heating (ECRH) alone. Comparison of experimental results with calculations by the transport code PRETOR [IAEA Technical Conference on Advances in Simulation and Models of Thermonuclear Plasmas. Montreal 142 (International Atomic Energy Agency, Vienna 1992)] indicates that sawtooth stabili

A systematic study of the power threshold for L-H transition has been conducted in TCV. Only results from NB heated plasmas are reported. The dependencies of PLH on plasma current, plasma density and main ion species have been investigated. For Deuterium&# ...

Predictability of burning plasmas is a key issue for designing and building credible future fusion devices. In this context, an important effort of physics understanding and guidance is being carried out in parallel to JET experimental campaigns in H and D ...

The intensity of Be-9 + p nuclear fusion reactions was experimentally studied during second harmonic (2 omega CH) ion-cyclotron resonance heating (ICRH) and further analyzed during fundamental hydrogen minority ICRH of JET-ILW hydrogen and deuterium plasma ...

Plasmas with negative triangularity (NT) shape have been recently shown to be able to achieve H-mode levels of confinement in L-mode, avoiding detrimental edge localised modes. Therefore, this plasma geometry is now studied as a possible viable option for ...

A semi-Lagrangian code for the solution of the electrostatic drift-kinetic equations in straight cylinder configuration is presented. The code, CYGNE, is part of a project with the long term aim of studying microturbulence in fusion devices. The code has been constructed in such a way as to preserve a good control of the constants of motion, possessed by the drift-kinetic equations, until the nonlinear saturation of the ion-temperature-gadient modes occurs. Studies of convergence with phase space resolution

Generation of a swing electron cyclotron current drive (swing ECCD), i.e. driving alternated, symmetric, positive or negative local ECCD, during a single discharge and at constant total input EC power, was performed at the Tokamak a Configuration Variable ...

Experimental observations from a range of tokamaks show that neoclassical tearing modes (NTMs) are triggered at lower plasma pressure when the sawtooth period is longer. A multi-machine database from nine tokamaks has been established in order to extrapola ...

An interpretation of non-standard, central MHD events in the TCV tokamak during localized ECRH is presented. It is shown that the non-standard behaviour is a consequence of specific features in the electron temperature profile produced when ECRH power is deposited close to the q = 1 surface and by the advection and mixing of electron thermal energy resulting from a resistive MHD instability.

At sufficiently high poloidal beta beta(theta) and low collisionality, m/n = 3/2 tearing modes are excited in the DIII-D tokamak by a q = 1 sawtooth crash perturbation. The resulting islands of full radial width w are long lived and reduce global confinement (and beta(theta)) by up to 30%. These are tearing modes produced by the perturbed neoclassical bootstrap current destabilization of a seed island arising from the m/n = 2/2 sawtooth precursor. The tearing modes are metastable. Even if the modes are conv

Compact DT neutron generators based on accelerators are often built on the principle of a mixed beam operation, meaning that deuterium (D) and tritium (T) are both present in the ion beam and in the target. Moreover, the beam consists of a mixture of ions ...

The effect of plasma shape on confinement has been experimentally explored in the TCV tokamak revealing that the core electron heat transport is significantly reduced by a negative triangularity configuration, which could indicate a (partial) stabilization ...

The rapid formation of an electron internal transport barrier (eITB) is observed during a slow evolution (similar or equal to 200 ms) from a centrally peaked to a hollow current density profile, while all external actuators remain constant. The time consta ...

An effect due to fusion born triton production has been observed in JET high-performance deuterium plasma discharges with neutral beam injection (NBI) and H-minority ion cyclotron range of frequencies (ICRF) heating, using DD and deuterium tritium (DT) neu ...

Geodesic acoustic modes (GAMs) may generate strong oscillations in the radial electric field and therefore are considered as a possible trigger mechanism for the L-H transition. This contribution focuses on the characterization of GAMs in JET plasmas when ...

This paper reports simultaneous measurements of intrinsic toroidal and poloidal plasma rotation during the evolution of electron Internal Transport Barriers (eITBs) on TCV. A CXRS diagnostic-beam system provides ion parameter profiles for stationary pre-barrier formation and eITB sustainment phases with a 15mm spatial resolution across the entire barrier width. This special configuration is used to assess the role of Er and E ×B shearing for the eITBs sustainment and formation in TCV. Two eITBs targets were

Flux-tube (local) gyrokinetic codes are widely used to simulate drift-wave turbulence in magnetic confinement devices. While a large number of studies show that flux-tube codes provide an excellent approximation for turbulent transport in medium-large devi ...

Olivier Sauter

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Edge localized modes in DIII-D high performance discharges

Modeling ICRH and ICRH-NBI Synergy in High Power JET Scenarios Using European Transport Simulator (ETS)

Impact of the plasma operation on the technical requirements in EU-DEMO

Central electron temperature enhancements due to sawtooth stabilization during counter electron cyclotron current drive in Tokamak a Configuration Variable

L-H power threshold for neutral beam heated plasmas with Deuterium, Hydrogen, Helium and mixed ion species in TCV

First principles and integrated modelling achievements towards trustful fusion power predictions for JET and ITER

Evidence of Be-9 + p nuclear reactions during 2 omega(CH) and hydrogen minority ICRH in JET-ILW hydrogen and deuterium plasmas

First-principle based predictions of the effects of negative triangularity on DTT scenarios

A semi-Lagrangian code for nonlinear global simulations of electrostatic drift-kinetic ITG modes

Modulation of electron transport during Swing ECCD discharges in TCV

Empirical scaling of sawtooth period for onset of neoclassical tearing modes

Model for humpback relaxation oscillations

Threshold for metastable tearing modes in DIII-D

Modelling of the neutron production in a mixed beam DT neutron generator

The effect of plasma triangularity on turbulent transport:modelling TCV experiments by linear and non linear gyrokinetic simulations

Rapid electron internal transport barrier formation during magnetic shear reversal in fully non-inductive TCV discharges

On a fusion born triton effect in JET deuterium discharges with H-minority ion cyclotron range of frequencies heating

Geodesic acoustic mode evolution in L-mode approaching the L-H transition on JET

Rotation studies in electron Internal Transport Barriers on TCV

How accurate are flux-tube (local) gyrokinetic codes in modeling energetic particle effects on core turbulence?