Papers by Guillaume Darmet
2021 IEEE PES Innovative Smart Grid Technologies Europe (ISGT Europe), 2021
Nuclear Fusion, 2009
The main results of the Tore Supra experimental programme in the years 2007-2008 are reported. Th... more The main results of the Tore Supra experimental programme in the years 2007-2008 are reported. They document significant progress achieved in the domain of steady-state tokamak research, as well as in more general issues relevant for ITER and for fusion physics research. Three areas are covered: ITER relevant technology developments and tests in a real machine environment, tokamak operational issues for high power and long pulses, and fusion plasma physics. Results presented in this paper include: test and validation of a new, load-resilient concept of ICRH antenna and of an inspection robot operated under ultra-high vacuum and high temperature conditions; an extensive experimental campaign (5 h of plasma) aiming at deuterium inventory and carbon migration studies; real-time control of sawteeth by ECCD in the presence of fast ion tails; ECRHassisted plasma startup studies; dimensionless scalings of transport and turbulence; transport experiments using active pertubation methods; resistive and fast-particle driven MHD studies. The potential role of Tore Supra in the worldwide fusion programme before the start of ITER operation is also discussed.
Nuclear science and …, 1988
Page 1. ICAPP'11, May 2-5,Nice, France A NEW APPROACH TO DETERMININE SODIUM BOILING ONSET OC... more Page 1. ICAPP'11, May 2-5,Nice, France A NEW APPROACH TO DETERMININE SODIUM BOILING ONSET OCCURENCE DURING ULOF TRANSIENTS. Guillaume DARMET, Simone MASSARA, Damien SCHMITT EDF R&D, 1 Av. ... Initial works by DC Wade et al. ...
Nuclear Engineering and Design, 2014
h i g h l i g h t s
Plasma Physics and Controlled Fusion, 2007
Critical physical issues can be specifically tackled with the global full-f gyrokinetic code GYSE... more Critical physical issues can be specifically tackled with the global full-f gyrokinetic code GYSELA. Three main results are presented. First, the selfconsistent treatment of equilibrium and fluctuations highlights the competition between two compensation mechanisms for the curvature driven vertical charge separation, namely, parallel flow and polarization. The impact of the latter on the turbulent transport is discussed. In the non-linear regime, the benchmark with the Particle-In-Cell code ORB5 looks satisfactory. Second, the transport scaling with ρ * is found to depend both on ρ * itself and on the distance to the linear threshold. Finally, a statistical steady-state turbulent regime is achieved in a reduced version of GYSELA by prescribing a constant heat source.
Journal of Nuclear Materials, 2007
Turbulence spreading, namely turbulent transport extending into a stable region is reported both ... more Turbulence spreading, namely turbulent transport extending into a stable region is reported both for the flat density profiles in the far SOL and into a modeled H-mode barrier. It is shown that due to turbulence penetration, the pedestal width fluctuates and that its effective width is a factor 2 smaller than the linear predicted width. Turbulence overshooting throughout the pedestal leads to a non-vanishing turbulent transport within the barrier and provides a coupling of core and SOL turbulence despite the transport barrier.
Journal of Nuclear Materials, 2009
a b s t r a c t SOL turbulence is characterised by intermittent ballistic transport of density fr... more a b s t r a c t SOL turbulence is characterised by intermittent ballistic transport of density fronts. The interaction of such density structures with velocity shear layers is found to yield shearing effects over scales that are comparable to those of the fronts. Enhanced diffusion transport governed by the thinning of the radial extent of the density structure governs the decay of such a structure over a Dupree time. Velocity shear layers extending poloidally over a fraction of the poloidal wave length can also exhibit a stopping capability due to the collapse of the radial velocity within the shear layer. The penetration of the density structure within such a barrier is of the order of five hybrid Larmor radius.
Journal of Nuclear Materials, 2005
The intermittent transport in the SOL is analysed in terms of the interaction between the average... more The intermittent transport in the SOL is analysed in terms of the interaction between the average profile and the population of large transport events, the fronts. This provides the basis for the statistical analysis presented in this paper. Data from 2D numerical simulations is analysed here. The mean density e-folding length for the fronts is observed to be the same as that of the time average profile. The mean ballistic velocity of the fronts has a radial Mach number of 0.03. A symmetric distribution of poloidal Mach numbers is found, its width is comparable to that of the radial Mach number, DM $ 0.02. The small fronts are found to be isotropic, the larger fronts are elongated radially (aspect ratio $ 6). A characteristic poloidal scale is found, typically 7 Larmor radii.
Communications in Nonlinear Science and Numerical Simulation, 2008
ABSTRACT Flux driven kinetic transport is analysed for deeply trapped ion turbulence with the cod... more ABSTRACT Flux driven kinetic transport is analysed for deeply trapped ion turbulence with the code GYSELA. The main observation is the existence of a steady state situation with respect to the statistics, in particular the balance between the injected energy and the time averaged energy flowing out through the outer edge boundary layer. The temperature is characterised by a very bursty behaviour with a skewed PDF. Superimposed to these short time scale fluctuations, one finds a regime with a strong increase of the zonal flows and a quenching of the turbulent energy. During this phase of such a predator-prey cycle, the core temperature rapidly increases while the edge temperature gradually decreases. The end of this reduced transport regime is governed by the onset of turbulence that governs large relaxation events, and a strong modification of the zonal flow pattern.
Nuclear Fusion, 2009
The main results of the Tore Supra experimental programme in the years 2007-2008 are reported. Th... more The main results of the Tore Supra experimental programme in the years 2007-2008 are reported. They document significant progress achieved in the domain of steady-state tokamak research, as well as in more general issues relevant for ITER and for fusion physics research. Three areas are covered: ITER relevant technology developments and tests in a real machine environment, tokamak operational issues for high power and long pulses, and fusion plasma physics. Results presented in this paper include test and validation of a new, load-resilient concept of ion cycotron resonance heating antenna and of an inspection robot operated under ultra-high vacuum and high temperature conditions; an extensive experimental campaign (5 h of plasma) aiming at deuterium inventory and carbon migration studies; real-time control of sawteeth by electron cyclotron current drive in the presence of fast ion tails; ECRH-assisted plasma start-up studies; dimensionless scalings of transport and turbulence; transport experiments using active perturbation methods; resistive and fast-particle driven MHD studies. The potential role of Tore Supra in the worldwide fusion programme before the start of ITER operation is also discussed.
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Papers by Guillaume Darmet