Publications by Olivier Sauter

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Halo currents generated during unmitigated tokamak disruptions are known to develop rotating asymmetric features that are of great concern to ITER because they can dynamically amplify the mechanical stresses on the machine. This paper presents a multi-mach ...

The tokamak `a configuration variable (TCV) is a small-sized tokamak, where finite size effects (often called 'rho-star' or 'global' effects) could significantly impact the heat and particle fluxes, leading to discrepancies between gyrokinetic flux-tube re ...

This paper presents results of JET ITER-like wall L-mode experiments in hydrogen and deuterium (D) plasmas, dedicated to the study of the isotope dependence of ion heat transport by determination of the ion critical gradient and stiffness by varying the io ...

The effects of negative triangularity () on confinement and fluctuations in plasmas covering a large range of parameters were investigated on the tokamak à configuration variable (TCV). The conditions explored in this paper include discharges where neutral ...

The effect of fast ions on turbulent particle transport, driven by ion temperature gradient (ITG)/trapped electron mode turbulence, is studied. Two neutral beam injection (NBI) heated JET discharges in different regimes are analyzed at the radial position ...

Transport modelling of Joint European Torus (JET) dimensionless collisionality scaling experiments in various operational scenarios is presented. Interpretative simulations at a fixed radial position are combined with predictive JETTO simulations of temper ...

Recent achievements in studies of the effects of ICRF (Ion Cyclotron Range of Frequencies) power on the SOL (Scrape-Off Layer) and PWI (Plasma Wall Interactions) in ASDEX Upgrade (AUG), Alcator C-Mod, and JET-ILW are reviewed. Capabilities to diagnose and ...

Ion cyclotron heating and current drive at omega approximate to 2omega(cH) in JET deuterium plasmas with a hydrogen concentration n(H)/(n(D)+n(H)) in the range of 5-15% are analysed, comparing results of numerical computer modelling with experiments. Second harmonic hydrogen damping is found to be maximized by placing the resonance on the, low-field side (LFS) of the torus, which minimizes competing direct electron damping and parasitic high-harmonic D damping in the presence of D beams. The shape of the ca

DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with funda ...

This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another (pulse 92432) from after the installation of JET's ITER-like Wall (ILW). Th ...

Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER and EU DEMO. A major objective of the AUG programme is to shed light on the underlying physics of confinement, stability, and plasma exhaust in order to ...

Helium is widely used as a fuel or minority gas in laboratory fusion experiments, and will be present as ash in DT thermonuclear plasmas. It is therefore essential to have a good understanding of its atomic physics. To this end He II population modelling h ...

High external gas injection rates are foreseen for future devices to reduce divertor heat loads and this can influence pedestal stability. Fusion yield has been estimated to vary as strongly as T-e,ped(2) so an understanding of the underlying pedestal phys ...

In this paper, the dynamic characteristics of type-I ELM time-series from the JET tokamak, the world's largest magnetic confinement plasma physics experiment, have been investigated. The dynamic analysis has been focused on the detection of nonlinear struc ...

The research programme performed on the Mega Amp Spherical Tokamak (MAST) Upgrade experiment has made significant advances in developing the physics understanding of low aspect ratio tokamaks in support of the operation of ITER and design of fusion powerplants. High performance plasma scenarios have been developed to facilitate a broad programme of experiments, in which confinement is constrained by the presence of m/n = 2/1 modes that cause substantial losses of fast ions. The onset of these modes coincide

A general feature of particle transport in the core of tokamak plasmas is that when core particle sources are small, a stationary peaked density profile is provided by a balance of outward diffusion and inward convection, driven by either neoclassical or t ...

To understand the fuel retention mechanism correlation of surface chemical states and hydrogen isotope retention behavior determined by XPS (X-ray photoelectron spectroscopy) and TDS (Thermal desorption spectroscopy), respectively, for JET ITER-Like Wall s ...

The present paper offers an overview of the potential of ion cyclotron resonance heating (ICRH) or radio frequency heating for the DEMO machine. It is found that various suitable heating schemes are available. Similar to ITER and in view of the limited ban ...

A neoclassical tearing mode (NTM) requires a finite size seed island to become unstable. Usually the local pressure gradient is relatively large at the beta-values needed for these seed islands to destabilize the NTMs. Therefore, the island has a large growth rate at mode onset and grows rapidly to its saturated island width. This width is proportional to as long as it is well above the marginal beta-limit below which the mode is stable. The marginal beta-limit is independent of the seed island trigger mech

We present results from a new Kinetic-Equilibrium Prediction (KEP) workflow and shot preparation for full TCV discharges, by coupling predict-first RAPTOR transport simulations with FBT inverse equilibrium calculations. RAPTOR is a 1.5D transport code which has been extensively used for plasma shot optimization and real-time modeling. We show that rapid pre-shot simulations can be performed directly using information from the pulse schedule across a wide range of plasma shapes and scenar

Olivier Sauter

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A multi-machine scaling of halo current rotation

Global 'zero particle flux-driven' gyrokinetic analysis of the density profile for a TCV plasma

Role of fast ion pressure in the isotope effect in JET L-mode plasmas

Effects of collisionality and T e /T i on fluctuations in positive and negative δ tokamak plasmas

Impact of fast ions on density peaking in JET: fluid and gyrokinetic modeling

Interpretative and predictive modelling of Joint European Torus collisionality scans

Impact of ICRF on the scrape-off layer and on plasma wall interactions: From present experiments to fusion reactor

Analysis of ion cyclotron heating and current drive at omega approximate to 2 omega(cH) for sawtooth control in JET plasmas

DIII-D research advancing the physics basis for optimizing the tokamak approach to fusion energy

Direct gyrokinetic comparison of pedestal transport in JET with carbon and ITER-like walls

Overview of ASDEX upgrade results in view of ITER and DEMO

Population modelling of the He II energy levels in tokamak plasmas: I. Collisional excitation model

Pedestal structure and energy confinement studies on TCV

Nonlinear dynamic analysis of D-alpha signals for type I edge localized modes characterization on JET with a carbon wall

Overview of the MAST Upgrade physics programme: testing novel concepts at low aspect ratio to inform future devices

The role of ion and electron electrostatic turbulence in characterizing stationary particle transport in the core of tokamak plasmas

Correlation of surface chemical states with hydrogen isotope retention in divertor tiles of JET with ITER-Like Wall

Ion cyclotron resonance heating scenarios for DEMO

Marginal beta-limit for neoclassical tearing modes in JET H-mode discharges

Kinetic Equilibrium Prediction at TCV using RAPTOR and FBT