A5075040470- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Physics of Superconductivity and Magnetism
- Computational Fluid Dynamics and Aerodynamics
- Dust and Plasma Wave Phenomena
- Gas Dynamics and Kinetic Theory
- Nuclear Engineering Thermal-Hydraulics
- Laser-induced spectroscopy and plasma
- Fluid Dynamics and Turbulent Flows
- Fractional Differential Equations Solutions
- Numerical methods for differential equations
- Geophysics and Sensor Technology
- Fluid Dynamics and Vibration Analysis
- Earthquake Detection and Analysis
- Quantum chaos and dynamical systems
- Advanced Sensor Technologies Research
- Magnetic Field Sensors Techniques
- Metallurgy and Material Forming
National Institutes for Quantum Science and Technology
2016-2024
National Institute for Fusion Science
2016-2024
Fusion Academy
2019-2024
Fusion (United States)
2019-2024
Royal Military Academy
2020
Japan Atomic Energy Agency
2007-2016
Oak Ridge National Laboratory
2009
General Atomics (United States)
2008
University College Cork
2008
Advanced Science Research Center
2006
Abstract The JET 2019–2020 scientific and technological programme exploited the results of years concerted engineering work, including ITER-like wall (ILW: Be W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power 2019–2020, tested technical procedural preparation for safe operation with tritium. Research along three complementary axes yielded wealth new results. Firstly, plasma delivered scenarios...
The pressure at the top of edge transport barrier (or ‘pedestal height’) strongly impacts fusion performance, while large localized modes (ELMs), driven by free energy in pedestal region, can constrain material lifetimes. Accurately predicting height and ELM behavior ITER is an essential element prediction optimization performance. Investigation intermediate wavelength MHD ‘peeling–ballooning’ modes) has led to improved understanding important constraints on mechanism for ELMs. combination...
The 2014–2016 JET results are reviewed in the light of their significance for optimising ITER research plan active and non-active operation. More than 60 h plasma operation with first wall materials successfully took place since its installation 2011. New multi-machine scaling type I-ELM divertor energy flux density to is supported by principle modelling. relevant disruption experiments modelling reported a set three mitigation valves mimicking setup. Insights L–H power threshold Deuterium...
A global gyrokinetic toroidal full- f five-dimensional Vlasov simulation GT5D (Idomura et al 2008 Comput. Phys. Commun. 179 391)is extended including sources and collisions. Long time tokamak micro-turbulence simulations in open system plasmas are enabled for the first based on a approach with self-consistent evolutions of turbulent transport equilibrium profiles. The neoclassical physics is implemented using linear Fokker–Planck collision operator, radial electric field E r determined...
Abstract For the past several years, JET scientific programme (Pamela et al 2007 Fusion Eng. Des . 82 590) has been engaged in a multi-campaign effort, including experiments D, H and T, leading up to 2020 first with 50%/50% D–T mixtures since 1997 ever plasmas ITER mix of plasma-facing component materials. this purpose, concerted physics technology was launched view prepare campaign (DTE2). This paper addresses key elements developed by directly contributing preparation. intense preparation...
The plasma rotation necessary for stabilization of resistive-wall modes (RWMs) is investigated by controlling the toroidal with external momentum input injection tangential neutral beams. observed threshold 0.3% Alfvén velocity and much smaller than previous experimental results obtained magnetic braking. This low critical has a very weak beta dependence as ideal wall limit approached. These indicate that large plasmas such in future fusion reactors rotation, requirement additional feedback...
This paper reports the progress made at JET-ILW on integrating requirements of reference ITER baseline scenario with normalized confinement factor 1, a pressure 1.8 together partially detached divertor whilst maintaining these conditions over many energy times. The 2.5 MA high triangularity ELMy H-modes are studied two different configurations D-gas injection and nitrogen seeding. power load reduction N seeding is reported. relationship between an increase in pedestal investigated....
New H-mode regimes with high confinement, low core impurity accumulation, and small edge-localized mode perturbations have been obtained in magnetically confined plasmas at the Joint European Torus tokamak. Such are achieved by means of optimized particle fueling conditions input power, current, magnetic field, which lead to a self-organized state strong increase rotation ion temperature decrease edge density. An interplay between plasma regions leads reduced turbulence levels outward...
The objective of thermonuclear fusion consists producing electricity from the coalescence light nuclei in high temperature plasmas. most promising route to envisages confinement such plasmas with magnetic fields, whose studied configuration is tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one main potential showstoppers on a commercial reactor. In this work we report how, deploying innovative analysis methods thousands JET experiments covering isotopic...
Abstract In the late 1990s, fusion scientists at Japanese tokamak JT-60U discovered abrupt large-amplitude events during beam-driven deuterium plasma experiments. A large spike in magnetic fluctuation signal followed by a drop neutron emission rate indicates that energetic ions abruptly migrate out of core an intense burst Alfvén waves lasts only 0.3 ms. With continued beam injection, ion population recovers until next event occurs 40–60 ms later. Here we present results from simulations...
The mechanism of improving energy confinement with argon seeding at high density has been investigated in JT-60U. Better is sustained by accompanied higher core and pedestal temperatures. electron profiles become flatter increasing conventional H-mode plasmas, whereas peaked are maintained seeding. Density peaking dilution effects lower the a given averaged density. seeded which than that plasmas deuterium puff, enables temperature to be higher, increase pressure small. High boundary...
We have observed a bursting mode in the high-$\ensuremath{\beta}$ plasmas above ideal $\ensuremath{\beta}$ limit without conducting wall. The frequency is chirping down as amplitude increases, and its initial value close to precession of trapped energetic particle from perpendicular neutral beams. structure radially extended with peak around $q=2$ surface. This can finally trigger resistive wall (RWM) despite enough plasma rotation for RWM stabilization. It concluded that driven by...
Abstract Nonlinear multiscale gyrokinetic simulations of a Joint European Torus edge pedestal are used to show that electron-temperature-gradient (ETG) turbulence has rich three-dimensional structure, varying strongly according the local magnetic-field configuration. In plane normal magnetic field, steep electron temperature gradient gives rise anisotropic with radial (normal) wavelength much shorter than in binormal direction. parallel direction, location and extent determined by variation...
Abstract Large edge localised modes (ELMs) would cause an unacceptable reduction of material lifetime in future large tokamaks due to the significant amount energy expelled from magnetically confined region towards plasma facing components. Thoroughly validated modelling regimes devoid ELMs is crucial as it may then provide predictive insights prior tokamak operation and design. This paper describes recent efforts pursued with non-linear extended MHD code JOREK three scenarios without ELMs:...
Abstract A new H-mode regime at low density and edge safety factor ( q 95 = 3.2, with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>I</mml:mi> <mml:mi mathvariant="normal">p</mml:mi> </mml:mrow> </mml:msub> </mml:math> 3 MA) that combines high energy confinement, stationary conditions for radiation small Edge Localized Modes (ELMs) have been found in JET Be/W wall. Such a is achieved by operating without external gas puffing,...
This paper reports the recent development of reversed shear plasmas with a high bootstrap current fraction (fBS) towards reactor relevant regime. The previous operation regime fBS is limited at q95 > 8 because low beta limit, whereas = 5–6 envisaged in DEMO reactor. In 2008 JT-60U experimental campaign, plasma was emphasized lower by developing large volume configuration close to conducting wall for stabilization. Thanks stabilization, exceeding no-wall limit are obtained ∼ 5.3. Though...
Recurring bursts of chirping Alfvén modes that were observed in JT-60U tokamak plasmas driven by negative-ion-based neutral beams (N-NB) are reproduced first-principle simulations performed with an extended version the hybrid code MEGA. This simulates interactions between gyrokinetic fast ions and magnetohydrodynamic (MHD) presence a realistic ion source collisions, so it self-consistently captures dynamics across wide range time scales (0.01–100 ms). The simulation confirms experimentally...
Abstract DIII-D physics research addresses critical challenges for the operation of ITER and next generation fusion energy devices. This is done through a focus on innovations to provide solutions high performance long pulse operation, coupled with fundamental plasma understanding model validation, drive scenario development by integrating core boundary plasmas. Substantial increases in off-axis current efficiency from an innovative top launch system EC power, pressure broadening Alfven...
We have observed a fishbone-like mode in high-β plasmas above the ideal β limit without conducting wall. The frequency chirps down, and its initial value is close to precession of trapped fast ions produced by perpendicularly injected neutral beams. This can often induce resistive wall (RWM). mainly N plasma where an kink-ballooning (IKBM) RWM are marginally stable. Since this were simultaneously observed, attributed interaction between stable IKBM stabilized Actually, MARG2D analysis shows...
Effects of a sheared toroidal rotation are investigated numerically on the stability MHD modes in tokamak edge pedestal, which relate to type-I edge-localized mode. A linear code MINERVA is newly developed for solving Frieman–Rotenberg equation that ideal with flow. Numerical analyses this reveal destabilizes localized frequencies experimentally achievable, though ballooning mode changes little by rotation. This effect becomes stronger as number unstable increases when analysis was performed...