L. Horváth
A5010493653- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Image and Signal Denoising Methods
- High-Energy Particle Collisions Research
- NMR spectroscopy and applications
- Botany and Plant Ecology Studies
- Atomic and Subatomic Physics Research
- Advanced Chemical Sensor Technologies
- Blind Source Separation Techniques
- Mathematical Inequalities and Applications
- Spectroscopy and Chemometric Analyses
- Water Quality Monitoring and Analysis
- Redox biology and oxidative stress
- Electrochemical Analysis and Applications
- Animal Diversity and Health Studies
- Chemistry and Chemical Engineering
- Plant responses to elevated CO2
University of York
2016-2025
Culham Science Centre
2017-2024
United Kingdom Atomic Energy Authority
2021-2024
Princeton Plasma Physics Laboratory
2023-2024
Culham Centre for Fusion Energy
2017-2023
Budapest University of Technology and Economics
2011-2022
University of Opole
2022
École Polytechnique Fédérale de Lausanne
2021
Royal Military Academy
2020
Fusion (United States)
2019
The dependence of plasma transport and confinement on the main hydrogenic ion isotope mass is fundamental importance for understanding turbulent and, therefore, accurate extrapolations from present tokamak experiments, which typically use a single hydrogen isotope, to burning plasmas such as ITER, will operate in deuterium–tritium mixtures. Knowledge properties edge barrier formation species critical view initial, low-activation phase ITER operations or helium its implications subsequent...
Abstract The JET hybrid scenario has been developed from low plasma current carbon wall discharges to the record-breaking Deuterium-Tritium plasmas obtained in 2021 with ITER-like Be/W wall. development started pure Deuterium refinement of current, and toroidal magnetic field choices succeeded solving heat load challenges arising 37 MW injected power ITER like environment, keeping radiation edge core controlled, avoiding MHD instabilities reaching high neutron rates. have re-run Tritium...
Abstract We present the results of GENE gyrokinetic calculations based on a series JET–ITER-like-wall (ILW) type I ELMy H-mode discharges operating with similar experimental inputs but at different levels power and gas fuelling. show that turbulence due to electron-temperature-gradient (ETGs) modes produces significant amount heat flux in four JET–ILW discharges, and, when combined neoclassical simulations, is able reproduce for two low pulses. The simulations plausibly high-gas fluxes as...
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 As part the DTE2 campaign in JET tokamak, we conducted a parameter scan T and D-T complementing existing pulses H D. For different main ion masses, type-I ELMy H-modes at fixed plasma current magnetic field can have pedestal pressure varying by factor of 4 total changing from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>β</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">N</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo>...
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.
Abstract We present an overview of results from a series L–H transition experiments undertaken at JET since the installation ITER-like-wall (JET-ILW), with beryllium wall tiles and tungsten divertor. Tritium, helium deuterium plasmas have been investigated. Initial in tritium show ohmic transitions low density power threshold for ( P LH ) is lower than ones densities, while we still lack contrasted data to provide scaling high densities. In there notable shift which minimum <?CDATA...
Abstract The recent deuterium–tritium campaign in JET-ILW (DTE2) has provided a unique opportunity to study the isotope dependence of L-H power threshold an ITER-like wall environment (Be and W divertor). Here we present results from dedicated transition experiments at JET-ILW, documenting tritium plasmas, comparing them with matching deuterium hydrogen datasets. From earlier it is known that as plasma isotopic composition changes deuterium, through varying deuterium/hydrogen concentrations,...
Abstract The dimensionless isotope mass scaling experiment between pure Deuterium and Tritium plasmas with matched <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mo>∗</mml:mo> </mml:msup> </mml:math> , <mml:mi>ν</mml:mi> β n q <mml:msub> <mml:mi>T</mml:mi> <mml:mi>e</mml:mi> </mml:msub> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mi>i</mml:mi> has been achieved in JET L-mode dominant electron heating (NBI+ohmic) conditions....
Abstract This paper reports the first experiment carried out in deuterium–tritium addressing integration of a radiative divertor for heat-load control with good confinement. Neon seeding was time D–T plasma as part second campaign JET its Be/W wall environment. The technical difficulties linked to re-ionisation heat load are reported T and D–T. compares impact neon on plasmas their D counterpart detachment, localisation radiation, scrape-off profiles, pedestal structure, edge localised modes global
NBI-heated L-mode plasmas have been obtained in JET with the Be/W ITER-like wall (JET-ILW) H and D, matched profiles of dimensionless plasma parameters, ρ * , ν β q core confinement region same T i /T e Z eff .The achieved isotope identity indicates that scale invariance principle is satisfied these plasmas, where dominant instabilities are Ion Temperature Gradient (ITG) modes.The thermal energy time, Ω τ E,th scaled heat diffusivity, A χ /B identical D within error bars, indicating lack...
Abstract A reduction of the pedestal pressure with increasing separatrix density over ( n e sep / ped ) has been observed in JET. The physics behind this correlation is investigated. due to two distinct mechanisms. increase till ≈0.4 shifts radially outwards, decreasing peeling-balloning stability and reducing height. effect position saturates above ≈ 0.4. For higher values, ascribed increased turbulent transport and, likely, resistive MHD effects. reduces ∇ /n , η transport. This gradient...
In highly confined tokamak plasmas periodically appearing edge localized modes (ELMs) are accompanied by mode-like magnetohydrodynamic (MHD) activities with defined toroidal mode numbers.
The pedestal structure of type I ELMy H-modes has been analysed for JET-ILW.The electron pressure width is independent ρ* and increases proportionally to √β pol,PED .Additional broadening the observed, at constant β , with increasing ν* and/or neutral gas injection contribution atomic physics effects in setting cannot as yet be ruled out.Neutral penetration alone does not determine shape edge density profile ratio temperature scale lengths transport barrier region, η e order 1.5-2.The...
The self-consistent core-pedestal prediction model of a combination EPED1 type pedestal and simple stiff core transport is able to predict Type I ELMy (edge localized mode) pedestals large JET-ILW (ITER-like wall) database at the similar accuracy as obtained when experimental global plasma β used input. neutral penetration [R. J. Groebner et al., Phys. Plasmas 9, 2134 (2002)] with corrections that take into account variations due gas fueling triangularity density an average error 15%....
The isotope dependence of plasma transport will have a significant impact on the performance future D-T experiments in JET and ITER eventually fusion gain economics reactors. In preparation for operation JET, dedicated comprehensive analyses were performed H, D H-D mixed plasmas. analysis data has demonstrated an unexpectedly strong favourable global confinement energy, momentum particles ELMy H-mode plasmas atomic mass main ion species, energy time scaling as ${\tau _E}\sim {A^{0.5}}$...
Abstract JET-ILW type I ELMy H-modes at 2.5 MA/2.8 T with constant NBI heating (23 MW) and gas fuelling rate were performed, utilising edge localised mode (ELM) pacing by vertical kicks plasma shaping (triangularity, δ ) as tools to disentangle the effects of ELMs, inter-ELM transport stability on pedestal particle balance. In agreement previous studies, confinement improves increasing , mostly due a significant increase in density while ELM frequency ( <?CDATA $f_{\mathrm{ELM}}$?> <mml:math...
Abstract Alfvén eigenmodes (AEs) and energetic particle modes (EPMs) are often excited by particles (EPs) in tokamak plasmas. One of the main open questions concerning EP driven instabilities is non-linear evolution mode structure. The aim present paper to investigate properties beta-induced AEs (BAEs) geodesic acoustic (EGAMs) observed ramp-up phase off-axis NBI heated ASDEX Upgrade (AUG) discharges. This focuses on changes structure BAEs/EGAMs during chirping phase. Our investigation has...
Abstract Mega Ampere Spherical Tokamak (MAST) pedestal data has been analysed, where a database of 892 shots was obtained, using the upgraded MAST Thomson scattering (TS) diagnostic. Various edge localised mode (ELM) types are discussed, characteristics and trends pedestals shown. The from TS diagnostic confirms found in earlier analysis, previous systems. Using database, calculations bootstrap current obtained different analytical formulae (Sauter Redl), comparisons performed. system now...
Measurements of the ion currents to and plasma conditions at low-field side (LFS) divertor target plate in low-confinement mode plasmas JET ITER-like wall materials configuration show that core density required detach LFS is independent hydrogenic species protium, deuterium tritium, a 40 %/60 % deuterium–tritium mixture. This observation applies with strike line connected horizontal part chosen because its superior diagnostic coverage. The finding operational status cryogenic pump. electron...
Abstract We present a comparative transport analysis of the isotope mass dependence in pedestal two pairs deuterium/hydrogen type I ELMy H-mode discharges JET with ITER-like wall, one characterized by same input power, other stored energy. The investigation, carried out using gyrokinetic code GENE, focuses on steep profile region pedestal. While large wavenumber modes mainly contribute to electron heat flux and are scarcely influenced main gas isotope, an effect ion agreement experimental...
Abstract The pedestal structure, edge transport and linear MHD stability have been analyzed in a series of JET with the ITER-like wall hydrogen (H) deuterium (D) type I ELMy H-mode plasmas. pressure is typically higher D than H at same input power gas rate, difference mainly due to lower density (Maggi et al (JET Contributors) 2018 Plasma Phys. Control. Fusion 60 014045). A balance analysis has shown that inter-ELM separatrix loss required maintain similar top pressure. This qualitatively...
Abstract Sustained operation of high-performance, ITER-baseline scenario plasmas at the high levels input power ( <?CDATA ${\lesssim}40\,\textrm{MW}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>≲</mml:mo> </mml:mrow> <mml:mn>40</mml:mn> <mml:mtext>MW</mml:mtext> </mml:math> ) required to achieve ∼15 MW D-T fusion in JET-ILW requires careful optimisation fuelling avoid an unacceptable disruption rate due excessive radiation, primarily from...
Abstract Experiments in ASDEX Upgrade (AUG) and JET with the ITER-like wall (JET-ILW) are performed to separate pedestal core contributions confinement H-modes different main ion masses. A strong isotope mass dependence is found which enhanced at high gas puffing. This because ELM type changes when going from D H for matched engineering parameters, likely due differences inter transport mass. The can be plasmas by varying only triangularity keeping parameters relevant same. With pedestals...
Abstract Unusually high power loads on the beryllium limiter caused by neutral beam re-ionisation, and much cooler divertor target surfaces were observed during recent JET tokamak tritium campaign. As both phenomena are driven scrape-off layer (SOL) physics, SOL features of 72 H-mode discharges their deuterium references have been studied. The majority (70) had exponentially decaying profiles. plasmas to increased separatrix density collisionality compared references. This is associated with...