Publications by Olivier Sauter

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Confinement in TCV electron cyclotron heated discharges was studied as a function of plasma shape, i.e. as a function of elongation, 1.1 < kappa < 2.15, and triangularity, -0.65 less than or equal to delta less than or equal to 0.55. The electron energy confinement time was found to increase with elongation, owing in part to the increase of plasma current with elongation. The beneficial effect of negative triangularities was most effective at low power and tended to decrease at the higher powers used. The l

Scientific and technical activities on JET focus on the issues likely to affect the ITER design and operation. Our understanding of the ITER reference mode of operation, the ELMy H-mode, has progressed significantly. The extrapolation of ELM size to ITER has been re-evaluated. Neoclassical tearing modes have been shown to be meta-stable in JET, and their beta limits can be raised by destabilization (modification) of sawteeth by ion cyclotron radio frequency heating (ICRH). Alpha simulation experiments with

The TCV tokamak has obtained ohmic H-modes in virtually all diverted plasmas with the ion del B drift directed towards an X-point and in several elongated limiter plasmas. Troyon factors (beta(tor)aB/l(p)) up to 2 and line average densities up to 2.2 x 10(20) m(-3), corresponding to the Greenwald limit, have been obtained in diverted ELM-free H-modes. Quasi-stationary H-modes lasting for the entire current flat top (1.5 s) have been obtained in the presence of regular ELMs. The occurrence and magnitude of E

Rapid inter-discharge simulation and optimization using the RAPTOR code have allowed the development of a reliable and reproducible early heating strategy for an advanced tokamak (AT) scenario on ASDEX Upgrade. Solving for electron heat and current diffusi ...

Plasma Turbulence studied by means of Correlation-ECE in the TEM domain in TCV Electron temperature fluctuations in the TEM domain have been measured in TCV using the correlation-ECE diagnostics [1]. Significant broadband electron temperature fluctuations are found radially extending between 0.3

The publication provide further insights into the dynamics of JET runaway electron (RE) beams mitigated by D2-rich shattered pellet injection (SPI) (Reux et al 2022 Plasma Phys. Control. Fusion 64 034002). Multi-diagnostic analyses show that mechanisms cau ...

The data of the H alpha high-resolution spectroscopy, collected on the multiple lines of sight, which cover the entire divertor space in poloidal cross-section, during the recent hydrogen-deuterium experiments in JET-ILW (ITER-like wall), are processed. A ...

Expressions for the neoclassical resistivity and the bootstrap current coefficients in terms of aspect ratio and collisionality are widely used in simulating toroidal axisymmetric equilibria and transport evolution. The formulas used are in most cases based on works done 15-20 years ago, where the results have been obtained for large aspect ratio, small or very large collisionality, or with a reduced collision operator. The best expressions to date and to our knowledge are due to Hirshman [S. P. Hirshman, P

When a plasma disrupts in a tokamak, significant heat and electromagnetic loads are deposited onto the surrounding device components. These forces scale with plasma current and magnetic field strength, making disruptions one of the key challenges for futur ...

This paper presents the transport analysis of high density baseline discharges in the 2016 experimental campaign of the Joint European Torus with the ITER-Like Wall (JET-ILW), where a significant increase in the deuterium-deuterium (D-D) fusion neutron rat ...

Radially localized electron cyclotron heating (ECH) at the 2nd harmonic (X2) is used to tailor the current profile through the modification of the temperature, and hence conductivity, profiles. The optimal conditions for current profile broadening are inve ...

A pedestal prediction model Europed is built on the existing EPED1 model by coupling it with core transport simulation using a Bohm-gyroBohm transport model to self-consistently predict JET-ILW power scan for hybrid plasmas that display weaker power degrad ...

The measurement of the energy spectra and densities of alpha-particles and other fast ions are part of the ITER measurement requirements, highlighting the importance of energy-resolved energetic-particle measurements for the mission of ITER. However, it ha ...

Disruptions can lead to potential damage to the fusion reactors and represent one of the major obstacles for the successful exploitation of the tokamak concept in commercial fusion power plants. The European Fusion Roadmap has identified disruptions as a high-priority research area. In the present experiments, a significant effort is devoted to address key physics and engineering issues connected to disruptions. The huge amount of data produced during the experiments in the various facilities is one of the

A 'hybrid' scenario for ITER is defined through its objectives: a large fusion yield for a long time duration. In many tokamaks, discharges characterized by a stationary current density profile, enclosing a large volume of low magnetic shear with q(0) near 1, have achieved improved confinement and higher beta limits. Their extrapolation to ITER from existing data corresponds to the ITER hybrid scenario. These discharges are characterized by soft MHD events. Physics issues relevant to the existence and extra

The EUROfusion Work Package JET3 programme, established to enable the technological exploitation of the JET experiments over the next years, includes, within the NEXP subproject, a novel Shutdown Dose Rate (SDR) experiment. Considering its ITER-relevance, ...

Operation of the JET tokamak with beryllium and tungsten ITER-like wall provides unique opportunity for detailed studies on dust generation: quantity, morphology, location, etc. The programme carried out in response to ITER needs for safety assessment comp ...

Neoclassical tearing modes are driven by the reduction of bootstrap current inside the island due to the flattening of the pressure profile. This current perturbation enhances the magnetic perturbation responsible for the island formation. Therefore it is well known that local current drive (CD) can be used to compensate this perturbation and stabilize the mode. Several forms of the current drive contribution to the modified Rutherford equation have been proposed. Analytical fits of these contributions are

In the preparation for the Deuterium-Tritium campaign, JET will operate with a tritium plasma. The T + T reaction consists of two notable channels: (1) T + T -> He-4 + 2n, (2) T + T -> He-5 + n -> He-4 + 2n. The reaction channel (1) is the reaction with th ...

The TCV tokamak (R = 0.88 in, a < 0.25 in, BT < 1.54 T) is equipped with six 0.5 MW gyrotron sources operating at 82.7 GHz for second harmonic X mode ECH. By distributing the ECCD current sources over the discharge cross section, fully driven stationary plasmas with I-p = 210 kA, n(e0) = 2 x 10(19) m(-3), T-e0 approximate to 4 keV, were obtained for the full discharge duration of 2 s. Highly peaked electron temperature profiles with T-e0 up to 12 keV were obtained in central counter-current drive scenarios

Olivier Sauter

Chat with Graph Search

Energy confinement and MHD activity in shaped TCV plasmas with localized electron cyclotron heating

Overview of JET results

Ohmic H-modes in the TCV tokamak

Inter-discharge optimization for fast, reliable access to ASDEX Upgrade advanced tokamak scenario

Plasma Turbulence studied by means of Correlation-ECE in the TEM domain in TCV

Dynamics of JET runaway electron beams in D2-rich shattered pellet injection mitigation experiments

Determination of isotope ratio in the divertor of JET-ILW by high-resolution H alpha spectroscopy: H-D experiment and implications for D-T experiment

Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime

Plasma state monitoring and disruption characterization using multimodal VAEs

High fusion performance at high T-i/T-e in JET-ILW baseline plasmas with high NBI heating power and low gas puffing

Current profile tailoring using localized electron cyclotron heating in highly elongated TCV plasmas

Integrated modelling of H-mode pedestal and confinement in JET-ILW

Diagnostic of fast-ion energy spectra and densities in magnetized plasmas

A Modern Framework to Support Disruption Studies: The Eurofusion Disruption Database

Hybrid advanced scenarios: perspectives for ITER and new experiments with dominant RF heating

Shutdown dose rate measurements after the 2016 Deuterium-Deuterium campaign at JET

Dust generation in tokamaks: Overview of beryllium and tungsten dust characterisation in JET with the ITER-like wall

On the contribution of local current density to neoclassical tearing mode stabilization

Activation material selection for multiple foil activation detectors in JET TT campaign

Overview of TCV results