A5046341166- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Atomic and Subatomic Physics Research
- Gyrotron and Vacuum Electronics Research
- Neuroscience and Music Perception
- Action Observation and Synchronization
- Antenna Design and Optimization
- Magnetic Field Sensors Techniques
- Particle Accelerators and Free-Electron Lasers
- Antenna Design and Analysis
- Fluid Dynamics and Turbulent Flows
- Electromagnetic Compatibility and Measurements
- Laser-induced spectroscopy and plasma
- Quantum, superfluid, helium dynamics
- Virtual Reality Applications and Impacts
- Spacecraft and Cryogenic Technologies
- Radiation Detection and Scintillator Technologies
Ghent University
2016-2025
Laboratoire de Physique des Plasmas
2017-2025
Royal Military Academy
2011-2024
Culham Centre for Fusion Energy
2016-2024
CEA Cadarache
2015-2020
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015-2020
Max Planck Institute for Plasma Physics
2015-2018
Max Planck Society
2015-2018
Culham Science Centre
2008-2016
Institut Jean Lamour
2015
Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external $n=1$ perturbation field generated by four error correction coils located far from plasma. During application of ELM frequency increased factor 4 and amplitude ${\mathrm{D}}_{\ensuremath{\alpha}}$ signal decreased. The energy loss per normalized to total stored energy, $\ensuremath{\Delta}W/W$, dropped values below 2%. Transport analyses shows no or only moderate (up 20%) degradation confinement...
Abstract Ion cyclotron resonance frequency (ICRF) heating has been an essential component in the development of high power H-mode scenarios Jet European Torus ITER-like wall (JET-ILW). The ICRF performance was improved by enhancing antenna-plasma coupling with dedicated main chamber gas injection, including preliminary minimization RF-induced plasma-wall interactions, while RF where optimized for core impurity screening terms ion position and minority hydrogen concentration. impact on...
This paper summarizes the physical principles behind novel three-ion scenarios using radio frequency waves in ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for and fast-ion generation multi-ion species plasmas. The theoretical section provides practical recipes selecting plasma composition realize scenarios, including two equivalent possibilities choice resonant absorbers that have been identified....
Abstract We present recent highlights from the most operation phases of Wendelstein 7-X, advanced stellarator in world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens seconds. Pellet fueling allows plasma reduced ion-temperature-gradient turbulence, during such phases, overall is so (energy often 200 ms) that attained density temperature profiles would not possible less optimized devices, since...
Emerging technologies in the domain of mixed reality offer rich, new possibilities for study and practice joint music performance. Apart from technological challenges, bringing players together raises important questions on their performance embodied coordination. In this study, we designed a platform to assess remote, bidirectional polyrhythmic interaction between two players, mediated real time by three-dimensional avatars shared, virtual 'drum circle'. We leveraged multi-layered analysis...
Results from the first measurements of a core plasma poloidal rotation velocity (upsilontheta) across internal transport barriers (ITB) on JET are presented. The spatial and temporal evolution ITB can be followed along with upsilontheta radial profiles, providing very clear link between location steepest region ion temperature gradient localized spin-up upsilontheta. an order magnitude higher than neoclassical predictions for thermal particles in region, contrary to close agreement found...
A minimal two-field fluid approach is followed to describe the radio-frequency (RF) wave propagation in bounded scrape-off layer plasma of magnetic fusion devices self-consistently with direct current (DC) biasing this plasma. The RF and DC parts are coupled by non-linear sheath boundary conditions at both ends open field lines. physical model studied within a simplified framework featuring slow (SW) only lateral walls normal straight confinement field. possibility however kept excite system...
The experiments carried out in hydrogen at the TOMAS facility show possibility of controlling plasma parameters such as temperature and electron density a combined cyclotron resonance radio frequency (ECR+RF) discharge. A maximum up to ≈6 × 1016 m−3 35 eV are observed ECR+RF propagation RF waves under weak magnetic field is analyzed. Depending on experimental conditions, radial distribution field, there can be several cases: only slow wave propagate, simultaneously fast or propagate....
A new deuterium-tritium experimental, DTE2, campaign has been conducted at the Joint European Torus (JET) between August 2021 and late December 2021. Motivated by significant enhancements in past decade JET, such as ITER-like wall enhanced auxiliary heating power, achieved a fusion energy world record performed broad range of fundamental experiments to inform ITER physics scenarios operations. New capabilities area product measurements nuclear diagnostics were available result long...
The operational domain for active control of type-I edge localized modes (ELMs) with an n = 1 external magnetic perturbation field induced by the ex-vessel error correction coils on JET has been developed towards more ITER-relevant regimes high plasma triangularity, up to 0.45, normalized beta, 3.0, current 2.0 MA and q95 varied between 3.0 4.8. results ELM mitigation in triangularity plasmas show that frequency ELMs increased a factor 4 during application fields, while energy loss per ELM,...
The present status of understanding toroidal and poloidal momentum transport in tokamaks is presented this paper.Similar energy confinement times, i.e. τ E /τ φ ≈ 1 have been reported on several tokamaks.It more important though, to study the local both core edge plasma separately as, for example, plasma, a large scatter ratio effective diffusivity ion heat χ φeff /χ i,eff among different can be found.For value Prandtl number typically around 0.2 JET while still holds.Perturbative NBI...
Dedicated experiments on TF ripple effects the performance of tokamak plasmas have been carried out at JET. The was found to a profound effect plasma rotation. central Mach number, M , defined as ratio rotation velocity and thermal velocity, drop function amplitude (δ) from an average value = 0.40–0.55 for operations standard JET δ 0.08% 0.25–0.40 0.5% 0.1–0.3 1%. should be considered when estimating in ITER. With co-current injection neutral beam (NBI), were rotate direction. However,...
The dependence of the H-mode edge transport barrier width on normalized ion gyroradius (ρ * = ρ/a) in discharges with type I ELMs was examined experiments combining data for JET and DIII-D tokamaks.The plasma configuration as well local pressure (β), collisionality (ν ), Mach number ratio electron temperature at pedestal top were kept constant, while ρ varied by a factor four.The steep gradient region (T e ) density (n pedestals
Recent JET experiments have been devoted to the study of (3He)–D plasmas involving radio frequency (RF) heating. This paper starts by discussing RF heating efficiency theoretically expected in such plasmas, covering both relevant aspects wave and particle dynamics. Then it gives a concise summary main conclusions drawn from recent that were either focusing on studying physics or adopting as tool plasma behavior. Depending minority concentration chosen, different physical phenomena are...
Abstract After a long device enhancement phase, scientific operation resumed in 2022. The main new components are the water cooling of all plasma facing and water-cooled high heat flux divertor units. Water allowed for first long-pulse campaign. A maximum discharge length 8 min was achieved with total heating energy 1.3 GJ. Safe demonstrated attached detached mode. Stable detachment is readily some magnetic configurations but requires impurity seeding small pitch angle within edge islands....
This paper reports on the recent studies of toroidal and poloidal momentum transport in JET. The ratio global energy confinement time to is found be close τ E /τ ϕ = 1 except for low density or collisionality discharges where 2–3. On other hand, local analysis around 40 shows that effective diffusivity ion heat χ /χ i ≈ 0.1–0.4 (averaged over radial region r / a 0.4–0.7) rather than unity, as expected from times used often ITER predictions. apparent discrepancy versus can at least partly...
We report the identification of a localized current structure inside JET plasma. It is field-aligned closed helical ribbon, carrying in same direction as background profile (cocurrent), rotating toroidally with ion velocity (corotating). appears to be located at flat spot plasma pressure profile, top pedestal. The spontaneously low density, high rotation plasmas, and can last up 1.4 s, time comparable local resistive time. considerably delays appearance first edge mode.Received 23 November...
At JET the dynamics of internal transport barriers (ITBs) has been explored by trying to decouple effects heating on one hand and torque other with ultimate objective identifying minimum required for formation barriers. The experiments shed light physics behind initial trigger ITBs, which often shows be linked shape q profile magnetic shear, while further development was influenced strength rotational shear. In discharges a small amount shear ITBs were triggered, suggest that overall is not...
Experimental evidence from the JET tokamak is presented supporting predictions of a recent theory (Graves et al 2009 Phys.Rev. Lett.102 065005) on sawtooth instability control by toroidally propagating ion cyclotron resonance waves.Novel experimental conditions minimized possible alternate effect magnetic shear modification current drive, and enabled dependence new energetic mechanism to be tested over key variables.The results have favourable implications waves in fusion reactor.
Using the unique capability of JET to monotonically change amplitude magnetic field ripple, without modifying other relevant equilibrium conditions, effect ripple on angular rotation frequency plasma column was investigated under conditions no external momentum input. The varied from 0.08% 1.5% in Ohmic and ion-cyclotron radio-frequency (ICRF) heated plasmas. In both cases causes counterrotation, indicating a strong torque due nonambipolar transport thermal ions case ICRF also fast ions.