A5046451780- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Atomic and Subatomic Physics Research
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor materials and devices
- High-Energy Particle Collisions Research
- Model Reduction and Neural Networks
- Dust and Plasma Wave Phenomena
- Sensor Technology and Measurement Systems
- Physics of Superconductivity and Magnetism
- Advanced Data Storage Technologies
- Metal and Thin Film Mechanics
- Aerodynamics and Fluid Dynamics Research
- Nuclear Materials and Properties
- Radio Wave Propagation Studies
- Metallurgical Processes and Thermodynamics
- HVDC Systems and Fault Protection
- Earthquake and Tsunami Effects
École Polytechnique Fédérale de Lausanne
2016-2025
Fusion (United States)
2002-2019
Fusion Academy
2002-2019
ITER
2019
CEA Cadarache
2002-2018
Plasma Technology (United States)
2018
Max Planck Institute for Plasma Physics
2015
Max Planck Society
2015
Princeton Plasma Physics Laboratory
2013
Laboratoire de Physique des Plasmas
2012-2013
Abstract The quasi-continuous exhaust (QCE) regime is a that naturally type-I ELM-free. It combines the high density at plasma edge needed for power with normalised energy confinement typical H-mode operation. In QCE large-scale ELMs are avoided and high-frequent, low-amplitude filaments present leading to name-giving transport of particles energy.
This contribution reports first time was successfully achieved in JET metal wall. More so, it demonstrated recent deuterium-tritium...
The mechanism for blob generation in a toroidal magnetized plasma is investigated using time-resolved measurements of two-dimensional structures electron density, temperature, and potential. blobs are observed to form from radially elongated structure that sheared off by the $\mathbf{E}\ifmmode\times\else\texttimes\fi{}\mathbf{B}$ flow. generated an interchange wave increases amplitude extends response decrease radial pressure scale length. dependence upon length discussed.
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 The quasi-continuous exhaust (QCE) regime, formerly known as either type-II ELM or small regime is studied in ASDEX Upgrade. a natural type-I ELM-free H-mode. operational space of QCE discharges Upgrade with respect to their separatrix conditions and power capabilities are presented. A significant broadening the fall-off length observed, correlating an increased density pressure. Moreover, possible reactor relevance this demonstrated by expanding low edge safety factor demonstrating...
Gradient driven electrostatic instabilities are investigated in TORPEX [A. Fasoli, B. Labit, M. McGrath, S. H. Müller, Podestà, and F. Poli, Bull. Am. Phys. Soc. 48, 119 (2003)], a toroidal device (R=1m, a=0.2m) which plasmas produced by microwaves (P⩽20kW) with frf=2.45GHz, the electron cyclotron frequency range. Typical density temperature ne⩽1017m−3 Te≃5eV, respectively. The magnetic field is mainly (⩽0.1T), small vertical component (⩽4mT). Instabilities that can be generally identified...
The radial propagation of blobs generated from plasma instabilities is investigated in an open magnetic field line configuration. Blob cross-field velocities and sizes are obtained internal probe measurements using pattern recognition. By varying the ion mass, normalized vertical blob scale a[over] scanned < 1 to > 1. An analytical expression for velocity including polarization currents, parallel currents sheath, ion-neutral collisions derived shows good quantitative agreement with...
The development of small Edge Localized Mode (ELM) scenarios is important in order to reduce the strain on plasma facing components.One such scenario can be found at high densities, highly shaped, close double-null plasmas ASDEX Upgrade, showing ELMs characterized by a frequency f ELM > 300Hz and low power loss.Changing from gas fuelling pellet results edge profiles which collisionality pedestal top separatrix are decoupled.While values remain unchanged, only phases with scrape-off layer...
A detailed cross-device investigation on the role of filamentary dynamics in high-density regimes has been performed within EUROfusion framework, comparing ASDEX Upgrade (AUG) and TCV tokamaks. Both devices run density ramp experiments at different levels plasma current, keeping toroidal field or q95 constant order to disentangle parallel connection length current. During scan a field, both scrape-off layer (SOL) profiles tend develop clear SOL shoulder lower edge whenever current is...
This paper presents the current wall-embedded Langmuir probe system installed on Tokamak à Configuration Variable (TCV), as well analysis tool chain used to interpret current-voltage characteristic obtained when probes are operated in swept-bias conditions. The is based a four-parameter fit combined with minimum temperature approach. In order reduce effect of plasma fluctuations and measurement noise, several characteristics usually averaged before proceeding fitting. impact this procedure...
Abstract The favorable confinement properties of negative-triangularity (NT) tokamak configurations were discovered in the TCV late 1990s and documented over two following decades, through investigations predominantly electron-heated plasmas limited topologies. most recent experimental campaign has marked a leap forward, characterized by development variety diverted NT shapes that are robustly stable with basic Ohmic heating. application auxiliary heating, directed now at both electrons ions...
One of our grand challenges towards fusion energy is the achievement a high-performance plasma core coupled to boundary solution. The high confinement mode (H-mode) provides such due build-up an edge transport barrier leading pedestal. However, it usually features type-I localized modes (ELMs) which pose threat for long-duration operation in future devices as they induce large fluences onto facing components and typically are projected damage first wall. For devices, integration stationary...
Tokamak operational regimes with small edge localized modes (ELMs) could be a solution to the problem of large transient heat loads in fusion reactors. A ballooning mode near last closed flux surface governed by pressure gradient and magnetic shear there has been proposed for ELMs. In this Letter, we experimentally investigate several stabilizing effects present linear ideal simulations that indeed develop ballooninglike fluctuations connect them nonlinear resistive simulations. The...
Abstract The work describes the pedestal structure, transport and stability in an effective mass ( A eff ) scan from pure deuterium to tritium plasmas using a type I ELMy H-mode dataset which key parameters that affect behaviour (normalized pressure, ratio of separatrix density density, ion Larmor radius, collisionality rotation) are kept as constant possible. Experimental results show significant increase at top with increasing , modest reduction temperature pressure. variations heights...
Abstract The impact of plasma shaping on the properties high density H-mode scrape-off layer (SOL) profiles and transport at outer midplane has been investigated Tokamakà configuration variable. experimental dataset acquired by evolving upper triangularity while keeping other parameters constant. scan comprises <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>δ</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">u</mml:mi>...
A unique parabolic relation is observed to link skewness and kurtosis of around ten thousand density fluctuation signals, measured over the whole cross section a toroidal magnetized plasma for broad range experimental conditions. All probability functions including those characterized by negative skewness, are universally described special case Beta distribution. Fluctuations in drift-interchange frequency necessary sufficient assure that can be this specific
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...
The TCV tokamak is augmenting its unique historical capabilities (strong shaping, strong electron heating) with ion heating, additional heating compatible high densities, and variable divertor geometry, in a multifaceted upgrade program designed to broaden operational range without sacrificing fundamental flexibility. rooted three-pronged approach aimed at ITER support, explorations towards DEMO, research. A 1 MW, tangential neutral beam injector (NBI) was recently installed promptly...
2019) 076038 (17pp) (mainly ETG and ITG) by 50%.This suggests that, in these plasmas, the increase turbulent transport due to outward shift of density might play an important role decrease pedestal performance.
Most of the detachment experiments done to date on tokamak à configuration variable (TCV), both in standard and alternative divertor geometries, focused L-mode integrated core density ramps. In view extending these studies high-power, high-confinement regimes, where impurity seeding will be necessary for detachment, properties nitrogen seeded TCV are assessed here with extensive set edge diagnostics similarities differences () ramp elucidated. It is found that high current, reversed field...
Abstract The EUROfusion JET-ILW pedestal database is described, with emphasis on three main issues. First, the technical aspects are introduced, including a description of data selection, datasets, diagnostics used, experimental and theoretical methods implemented definitions. Second, structure stability described. In particular, work describes links between engineering parameters (power, gas divertor configuration) disagreement peeling-ballooning (PB) model ideal magnetohydrodynamics...
Abstract Results of the first gyrokinetic simulations TCV pedestal are presented. Two discharges at varying levels gas puffing considered as input parameters for local GENE simulations. Linear and nonlinear carried out electron scale turbulence to determine role Electron Temperature Gradient (ETG) mode in transport. The heat flux associated with ETG is found be negligible compared total experimental lower puff. At higher puff, computed was find account values, demonstrating importance...
Abstract JET returned to deuterium-tritium operations in 2023 (DTE3 campaign), approximately two years after DTE2. DTE3 was designed as an extension of JET's 2022-2023 deuterium campaigns, which focused on developing scenarios for ITER and DEMO, integrating in-depth physics understanding control schemes. These were evaluated with mixed D-T fuel, using the only remaining tritium-capable tokamak until its closure 2023. A core-edge-SOL integrated H-mode scenario developed tested D-T, showing...
The mechanism for blob generation is detailed in the toroidal magnetized plasma of TORPEX device [Fasoli et al., Phys. Plasmas 13, 055902 (2006)] using an experimental configuration, which features a region dominated by coherent wave and on low field side characterized propagation blobs. Predictions from linearized 2D drift-reduced Braginskii equations are compared with data, revealing interchange nature wave. dynamics formation investigated time-resolved measurements two-dimensional...