A5040965793- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Planetary Science and Exploration
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Nuclear Materials and Properties
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Spacecraft and Cryogenic Technologies
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Spacecraft Design and Technology
- Dust and Plasma Wave Phenomena
- Atmospheric Ozone and Climate
- Calibration and Measurement Techniques
- Space Exploration and Technology
- Semiconductor materials and devices
- Advanced Data Storage Technologies
- Spacecraft Dynamics and Control
- High-Energy Particle Collisions Research
- Aerodynamics and Fluid Dynamics Research
- Thermal Analysis in Power Transmission
- Space exploration and regulation
Aix-Marseille Université
2018-2025
Centre National de la Recherche Scientifique
2018-2025
Princeton University
2023-2024
Princeton Plasma Physics Laboratory
2020-2024
European Space Astronomy Centre
2024
Institut Universitaire des Systèmes Thermiques Industriels
2023
Château Gombert
2023
HUN-REN Centre for Energy Research
2021
Royal Military Academy
2020
École Polytechnique Fédérale de Lausanne
2013-2019
Divertor detachment is explored on the TCV tokamak in alternative magnetic geometries. Starting from typical single-null shapes, poloidal flux expansion at outer strikepoint varied by a factor of 10 to investigate X-divertor characteristics, and total 70 study properties super-X divertor. The effect an additional X-point near target investigated divertors. Detachment studied these plasmas during Ohmic density ramps with ion B drift away primary X-point. threshold, depth detachment, stability...
Abstract In state-of-the-art stellarators, turbulence is a major cause of the degradation plasma confinement. To maximize confinement, which eventually determines amount nuclear fusion reactions, turbulent transport needs to be reduced. Here we report observation confinement regime in stellarator that characterized by increased and reduced fluctuations. The transition this driven injection submillimetric boron powder grains into plasma. With line-averaged electron density being kept...
Abstract Launched on 2 June 2003 and arriving at Mars 25 December after a 7-month interplanetary cruise, Express was the European Space Agency’s first mission to arrive another planet. After more than 20 years in orbit, spacecraft science payload remain good health has become second oldest operational planetary orbiter Odyssey. This contribution summarizes operations, planning data archiving systems, processes, teams that are necessary run mission, plan scientific observations, execute all...
TCV experiments demonstrate the basic power exhaust properties of snowflake (SF) plus and SF minus divertor configurations by measuring heat fluxes at each their four legs. The measurements indicate an enhanced transport into private flux region a reduction peak compared to similar single null configuration. There are indications that this cannot be explained modified field line geometry alone likely requires additional or cross-field channel. measurements, however, do not show broadening...
The inboard limiters for ITER were initially designed on the assumption that parallel heat flux density in scrape-off layer (SOL) could be approximated by a single exponential with decay length λq. This was found not to adequate 2012, when infra-red (IR) thermography measurements inner column during JET limiter discharges clearly revealed presence of narrow channel adjacent last closed surface. near-SOL occurs λq ∼ few mm, much shorter than main SOL λq, and can raise at apex factor up ∼4...
Pulsed injections of boron carbide granules into Wendelstein 7-X stellarator (W7-X) plasmas transiently increase the plasma stored energy and core ion temperatures above reference W7-X experimental programs by up to 30%. In a series 4 MW electron cyclotron resonance heating experiments, PPPL Probe Mounted Powder Injector provided 50 ms bursts 100 μm every 350 at estimated quantities ranging from approximately 1 mg/pulse over 30 mg/pulse. For each injection, was observed initially drop...
A large database of reciprocating probe data from the edge plasma TCV (Tokamak à Configuration Variable) is used to test radial velocity scalings filaments analytical theory [Myra et al., Phys. Plasmas 13, 112502 (2006)]. The measured velocities are mainly scattered between zero and a maximum which varies as function size collisionality in agreement with scalings. scatter consistent mechanisms that tend slow individual filaments. While were clustered 0.5 2 km/s, minority reached outward high...
Abstract Recently, experiments on basic plasma physics issues for solving future problems in fusion energy have been performed a Large Helical Device. There are several to be solved devices energy. Emerging burning are: alpha-channeling (ion heating by alpha particles), turbulence and transport electron dominant helium ash exhaust, reduction of the divertor heat load. To solve these problems, understanding (1) wave–particle interaction through (inverse) Landau damping, (2) characteristics...
Abstract Controlled particulate injections from the PPPL impurity powder dropper (IPD) into Large Helical Device have demonstrated positive effects on wall conditions both an intra and inter-shot basis. Injections over a range of densities, input powers, pulse lengths, heating schemes, injection quantities main ion species show conclusive evidence improvement to plasma conditions. Successful are confirmed by spectroscopic measurements as well real-time visible camera signals. In 7 s long...
A 3D multispecies fluid model has been implemented in the SOLEDGE-TOKAM suite of codes to address Scrape-off layer turbulent impurity transport. Zhdanov closure is used multi-component plasma modeling without any mass ordering or trace assumption. Thanks immersed boundary conditions, up wall simulations with non-axisymmetric facing components are performed, particular WEST configuration. first proof principle interchange turbulence simulation a Deuterium+Carbon also reported.
Injection of impurities in the form sub-millimeter powder grains is performed for first time Large Helical Device (LHD) plasma, employing Impurity Powder Dropper (IPD) (Nagy et al., 2018), developed and built by PPPL. Controlled amounts boron (B) nitride (BN) are injected into helical plasma. Visible camera imaging, UV charge exchange spectroscopy measurements show that effectively penetrate plasma two different magnetic configurations. The prompt effects on characterized as injection rate...
The aim of this work is to provide an understanding detachment at TCV with emphasis on analysis the Balmer line emission. A new Divertor Spectroscopy System has been developed for purpose. Further development techniques allowed detailed information be extracted from three-body recombination contribution n=7 intensity. During density ramps, plasma target detaches as inferred a drop in ion current target. At same time $6\rightarrow2$ and $7\rightarrow2$ emission near dominated by...
Abstract Recently an improved confinement regime, characterized by reduced turbulent fluctuations has been observed in the Large Helical Device upon injection of boron powder into plasma (Nespoli et al 2022 Nat. Phys. 18 350–56). In this article, we report more detail experimental observations increased temperature and decrease across cross section, on extended database. particular, compare powders different materials (B, C, BN), finding similar improvement turbulence response for three...
To address the risk that, in a fusion reactor, conventional single-null divertor (SND) configuration may not be able to handle power exhaust, alternative configurations, such as Snowflake (SFD), are investigated TCV. The expected benefits of SFD-minus terms load and peak heat flux discussed compared experimental measurements. In addition, key results obtained during last years summarized.
Heat flux profiles inferred from a reciprocating probe at the outer midplane of TCV tokamak during inner wall limited discharges feature radial fall-off lengths that shorten near last closed surface (LCFS) consistent with so-called narrow feature. The is significantly wider on outboard side compared measured by infrared thermography, so it difficult to discern main scrape-off layer After small shifts were applied for alignment, fraction power contained in matches between inboard and...
To investigate blob properties in the tokamak scrape-off layer (SOL), we perform dedicated numerical nonlinear simulations of plasma turbulence SOL a TCV discharge using Global Braginskii Solver code. A detection technique is used for first time three-dimensional (3D) full-turbulence simulation to track motion filaments SOL. The specific size, density amplitude and radial velocity blobs are computed, with typical values being , respectively. analysis structure parallel direction shows that...
Naked foil bolometers can reflect a significant fraction of incident energy and therefore cannot be used for absolute measurements. This paper outlines novel coating approach to address this problem by blackening the surface gold using physical vapour deposition. An experimental bolometer was built containing four standard bolometers, which two were coated with 100+ nm carbon. All collimated observed same relatively high temperature, ohmically heated plasma. Preliminary results showed...
We study the effect of a diverted magnetic geometry on edge plasma turbulence, focusing three-dimensional structure and dynamics filaments, also called blobs, in simulations WEST tokamak, featuring primary secondary X-point. For this purpose, addition to classical analysis techniques, we apply here novel fully 3D blob recognition tracking (BRAT) algorithm, allowing for first time resolve blobs turbulent realistic geometry. The results are tested against existing theoretical scalings velocity...