A5048431369- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- High-Energy Particle Collisions Research
- Solar and Space Plasma Dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear Materials and Properties
- Laser-induced spectroscopy and plasma
- Nuclear Engineering Thermal-Hydraulics
- Ion-surface interactions and analysis
- Molecular Junctions and Nanostructures
- Fullerene Chemistry and Applications
- Physics of Superconductivity and Magnetism
- Particle Accelerators and Free-Electron Lasers
- Quantum optics and atomic interactions
- Atomic and Subatomic Physics Research
- Quantum many-body systems
- Astro and Planetary Science
- Radiation Detection and Scintillator Technologies
Culham Science Centre
2015-2024
United Kingdom Atomic Energy Authority
2005-2024
Culham Centre for Fusion Energy
2012-2024
Institute of Science and Technology Austria
2020-2024
Royal Military Academy
2020
Institute of Contemporary Education "YurInfoR-MGU"
2019
Helmholtz-Zentrum Dresden-Rossendorf
2018
Moscow Institute of Physics and Technology
2018
École Polytechnique Fédérale de Lausanne
2005-2014
University of York
2013
The physical processes producing electron particle transport in the core of tokamak plasmas are described. Starting from gyrokinetic equation, a simple analytical derivation is used as guidance to illustrate main mechanisms driving turbulent convection. A review experimental observations on tokamaks presented and consistency with theoretical predictions discussed. An overall qualitative agreement, some cases even specific quantitative emerges between complex equally observations, exhibiting...
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...
Focused ion beams perfectly suit for patterning two-dimensional (2D) materials, but the optimization of irradiation parameters requires full microscopic understanding defect production mechanisms. In contrast to freestanding 2D systems, details damage creation in supported materials are not fully understood, whereas majority experiments have been carried out targets deposited on substrates. Here, we suggest a universal and computationally efficient scheme model which combines analytical...
For the first time, scalings for density peaking in tokamaks are obtained from a database consisting of observations two devices, ASDEX Upgrade and JET. The investigation relies on an inversion method interferometer signals which grants consistent reconstructions despite differences geometries. By combining these correlations between physics parameters investigated their role determining reduced. Multiple regression analyses show that combined collisionality is most relevant parameter....
The instrument function of the high resolution Thomson scattering (HRTS) diagnostic in Joint European Torus (JET) has been calculated for use improved pedestal profile analysis. full width at half maximum (FWHM) spatial response is (22 ± 1) mm original HRTS system configuration and depends on particular magnetic topology JET plasmas. An improvement to optical design laser input presented. smearing across flux surfaces reduced this design. new implemented (from JPN 78742, July 2009)...
In both JET and ASDEX Upgrade (AUG) the plasma energy confinement has been affected by presence of a metal wall requirement increased gas-fuelling to avoid tungsten pollution plasma.In with beryllium/tungsten high triangularity baseline H-mode scenario (i.e.similar ITER reference scenario) strongest benefit shaping give good normalised H 98 ~1 at Greenwald density fraction f GW ~0.8 disappeared.In AUG full could be achieved in plasmas, albeit elevated pressure β N >2.The lost respect carbon...
Type I ELMy H-mode operation in JET with the ITER-like Be/W wall (JET-ILW) generally occurs at lower pedestal pressures compared to those full carbon (JET-C). The density is similar but temperature where type ELMs occur reduced and below so-called critical I–type III transition reported JET-C experiments. Furthermore, confinement factor H98(y,2) baseline plasmas JET-ILW low power fractions Ploss/Pthr,08 < 2 (where Ploss (Pin − dW/dt), Pthr,08 L–H threshold from Martin et al 2008 (J. Phys....
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 A series of experiments have been executed at JET to assess the efficacy newly installed shattered pellet injection (SPI) system in mitigating effects disruptions. Issues, important for ITER disruption mitigation system, such as thermal load mitigation, avoidance runaway electron (RE) formation, radiation asymmetries during quench electromagnetic control and RE energy dissipation addressed over a large parameter range. The efficiency has examined various SPI strategies. paper...
In ion-temperature-gradient (ITG) driven turbulence, the resonance condition leads to ion particle turbulent transport coefficients significantly larger than electron coefficients. This is shown in nonlinear gyrokinetic simulations and explained by an analytical quasilinear model. It then illustrated JETTO-QuaLiKiz integrated modelling. Large implies that density profiles are uncorrelated corresponding source, allowing peaked isotope even absence of core source. also no strong accumulation...
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...
Experimental observations on core particle and impurity transport from the Axial Symmetric Divertor Experiment Upgrade [O. Gruber, H.-S. Bosch, S. Günter et al., Nucl Fusion 39, 1321 (1999)] Joint European Torus [J. Pamela, E. R. Solano, JET EFDA Contributors, Nucl. 43, 1540 (2003)] tokamaks are reviewed compared. Robust general experimental behaviors observed in both devices related parametric dependences identified. The compared with most recent theoretical results field of transport.
The density evolution during the transient phase just after L-H transition is investigated using theoretical transport models. Cases characterized by core densities which evolve in longer times ...
Particle transport has been extensively studied by performing several dimensionally matched collisionality scans in various plasma scenarios JET.Gas puff modulation technique developed with high quality time-dependent density profile measurements to determine particle coefficients.Density peaking found increase decreasing * all H-mode while L-mode, no dependency was found.The experimentally determined coefficients suggest that NBI fueling is main contributor the observed H-mode.This...
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...
Results from an extensive profile database analysis of JET density profiles in H-mode show that the peaking factor ne0/ < ne > H-modes increases as effective collisionality drops ∼1 at mid-radius to below 0.1 expected for ITER. Density is also strongly correlated with Greenwald number NG, particle outward flux Γ neutral beam source and Ti/Te. The correlations li, q95, βN, ρ*, LTe, LTi, toroidal Mach its shear are weak or insignificant. H- modes heated only by ICRH are, on average, slightly...
Abstract The required heating power, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>P</mml:mi> <mml:mi>LH</mml:mi> </mml:mrow> </mml:msub> </mml:math> , to access the high confinement regime (H-mode) in tritium containing plasmas is investigated JET with ITER-like wall at a toroidal magnetic field of <mml:mi>B</mml:mi> <mml:mi>t</mml:mi> <mml:mo>=</mml:mo> <mml:mn>1.8</mml:mn> T and plasma current <mml:mi>I</mml:mi>...
Intense electron cyclotron resonance heating (ECRH) and current drive (ECCD) are employed on the Tokamak à Configuration Variable (TCV) both in second- third-harmonic X-mode (X2 X3). The plasma behaviour under such conditions is driven largely by dynamics, motivating extensive studies of relaxation phenomena governing thermal suprathermal populations. In particular, dynamics electrons intimately tied to physics X2 ECCD. ECRH also a useful tool for manipulating distribution function physical...
As an independent complement to previous studies (Weisen et al 2005 Nucl. Fusion 45 L1–4 , Weisen 2006 Plasma Phys. Control. 48 A457–66 Angioni 2007 47 1326–35 ), density peaking in the JET tokamak was investigated on dataset, comprising virtually all H-mode experiments performed 2006–2007. Unlike studies, this work focuses low collisionality data as most representative of reactor conditions. The study confirms that is important parameter governing H-mode, followed by NBI particle flux...
ITER as a superconducting fusion machine needs efficient wall conditioning techniques for application in the presence of permanent high toroidal magnetic field (i) reducing in-vessel impurity content, (ii) controlling surface hydrogen isotopic ratio and (iii) mitigating long-term tritium inventory build-up. Encouraging results recently obtained with ion-cyclotron (ICWC) present-day tokamaks stellarators have raised ICWC to status one most promising available routine inter-pulse overnight...
The LIDAR Thomson scattering concept was proposed in 1983 and then implemented for the first time on JET tokamak 1987. A number of modifications were performed published 1995, but since no major changes made almost 15 years. In 2010 a refurbishment diagnostic started, with as main goals to improve its performance test potential new detectors which are considered candidates ITER. During subsequent years wide range activities aimed at increasing diagnostic's light throughput, improvement...
Particle transport in tokamak plasmas has been intensively studied the past, particularly relation to density peaking and presence of anomalous inward particle convection L- H-modes. While L-mode case pinch previously unambiguously demonstrated, H-mode was unclear. The main difficulty such studies is that diffusion could not be measured independently steady-state conditions a core flux. Therefore, it usually possible separate effect(inward convection), from source effect (slow particles...