A5057441121- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Dust and Plasma Wave Phenomena
- Nuclear reactor physics and engineering
- Physics of Superconductivity and Magnetism
- Stellar, planetary, and galactic studies
- Atomic and Subatomic Physics Research
- Astro and Planetary Science
- Nuclear Physics and Applications
- Astronomical Observations and Instrumentation
- Particle Dynamics in Fluid Flows
- Astronomy and Astrophysical Research
- Tropical and Extratropical Cyclones Research
- Particle Accelerators and Free-Electron Lasers
- Geophysics and Gravity Measurements
- Fluid Dynamics Simulations and Interactions
- Geomagnetism and Paleomagnetism Studies
- Fluid Dynamics and Turbulent Flows
- Semiconductor materials and devices
China Institute of Atomic Energy
2025
Chinese Academy of Agricultural Sciences
2024-2025
Zhejiang University
2016-2024
Princeton Plasma Physics Laboratory
2009-2020
Boston Fusion (United States)
2020
CEA Cadarache
2020
Institute of Ionized Gas
2020
University of Colorado Boulder
2018
Princeton University
1998-2014
Thornton Tomasetti (United States)
2010-2011
The toroidicity-induced shear Alfvén eigenmode is found to be destabilized by fusion alpha particles in an ignited tokamak plasma.
The question of how to proceed toward ever more realistic plasma simulation studies using increasing computing power is addressed. answer presented here the M3D (Multilevel 3D) project, which has developed a code package with hierarchy physics levels that resolve increasingly complete subsets phase-spaces and are thus realistic. rationale for multilevel models given. Each level described examples its application existing fluid (3D configuration space), namely magnetohydrodynamic (MHD)...
A new energetic particle-induced geodesic acoustic mode (EGAM) is shown to exist. The frequency and structure are determined nonperturbatively by particle kinetic effects. In particular the EGAM found be substantially lower than standard GAM frequency. radial width drift orbit can fairly large for high pressure safety factor. These results consistent with recent experimental observation of beam-driven $n=0$ in DIII-D.
Intense axisymmetric oscillations driven by suprathermal ions injected in the direction counter to toroidal plasma current are observed DIII-D tokamak. The modes appear at nearly half ideal geodesic acoustic mode frequency, plasmas with comparable electron and ion temperatures elevated magnetic safety factor (${q}_{\mathrm{min}}\ensuremath{\ge}2$). Strong bursting frequency chirping observed, concomitant large (10%--15%) drops neutron emission. Large density fluctuations...
Compact optimized stellarators offer novel solutions for confining high-β plasmas and developing magnetic confinement fusion. The three-dimensional plasma shape can be designed to enhance the magnetohydrodynamic (MHD) stability without feedback or nearby conducting structures provide drift-orbit similar tokamaks. These configurations possibility of combining steady-state low-recirculating power, external control, disruption resilience previous with low aspect ratio, high β limit, good...
Physics knowledge (theory and experiment) in energetic particles relevant to design of a reactor scale tokamak is reviewed, projections for ITER are provided this Chapter the Basis. The review includes single particle effects such as classical alpha heating toroidal field ripple loss, well collective instabilities that might be generated plasmas by particles. overall conclusion fusion expected provide an efficient plasma ignition sustained burn next step device. major concern localized heat...
Recent results on investigations of Alfvén eigenmodes, fast ion confinement and diagnostics in JT-60U are presented. It was found that toroidicity induced eigenmodes (TAEs) were stable negative shear discharges with a large density gradient at the internal transport barrier (ITB). If small ITB, multiple TAEs appeared around q = 2 surface (pitch minimum) showed frequency chirping (Δf ≈ 80 kHz). In low-q positive discharges, location changed from outside to inside 1 surface, owing temporal...
Peak fusion power production of 6.2\ifmmode\pm\else\textpm\fi{}0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total 29.5 MW. These have an inferred central alpha particle density 1.2\ifmmode\times\else\texttimes\fi{}${10}^{17}$ ${\mathrm{m}}^{\mathrm{\ensuremath{-}}3}$ without the appearance either disruptive magnetohydrodynamics events or detectable changes Alfv\'en wave activity. The measured loss rate energetic particles agreed with...
The stability of high-n toroidicity-induced shear Alfvén eigenmodes (TAE) in the presence fusion alpha particles or energetic ions tokamaks is investigated. TAE modes are discrete nature, and thus can easily tap free energy associated with particle pressure gradient through wave resonant interaction. A quadratic form derived for using gyrokinetic equation. kinetic effects calculated perturbatively ideal magnetohydrodynamic (MHD) solution as lowest-order eigenfunction. finite Larmor radius...
Global hybrid simulations of energetic particle effects on the n=1 internal kink mode have been carried out for tokamaks. For International Thermonuclear Experimental Reactor (ITER) [ITER Physics Basis Editors et al., Nucl. Fusion 39, 2137 (1999)], it is shown that alpha are stabilizing mode. However, elongation ITER reduces stabilization significantly. Nonlinear precessional drift fishbone instability circular tokamak plasmas show saturates due to flattening distribution function near...
Remarkable progress has been made in diagnosing energetic particle instabilities on presentday machines and establishing a theoretical framework for describing them.This overview describes the much improved diagnostics of Alfvén modelling tools developed world-wide, discusses interpreting observed phenomena.A multi-machine comparison is presented giving information performance both different plasma conditions outlining expectations ITER based our present knowledge.
The numerical methods used in the full particle-orbit following SPIRAL code are described and a number of physics studies performed with presented to illustrate its capabilities. is test-particle powerful tool interpret plan fast-ion experiments tokamaks. Gyro-orbit effects important for fast ions low-field machines such as NSTX lesser extent DIII-D. A interlaced between description Results on heat loads generated by localized error-field DIII-D wall compared measurements. enhanced Triton...
Alpha-particle-driven toroidal Alfvén eigenmodes (TAEs) have been observed for the first time in deuterium-tritium (D-T) plasmas on tokamak fusion test reactor (TFTR). These modes are 100–200 ms following end of neutral beam injection with reduced central magnetic shear and elevated safety factor [q0>1]. Mode activity is localized to region discharge r/a<0.5 fluctuation level B̃⊥/B∥∼10−5 mode numbers range n=2–4, consistent theoretical calculations α-TAE stability TFTR.Received 11 November...
The effects of finite drift orbit width (FOW) and Larmor radius (FLR) fast particles on the stability low-n toroidicity-induced Alfvén eigenmodes (TAE) are studied. formulation is based solution low frequency gyrokinetic equation (ω≪ωc, where ωc particle cyclotron frequency). A quadratic form has been derived in terms invariant variables; energy E, magnetic moment μ, toroidal angular momentum Pφ. growth rate TAE computed perturbatively using numerical averaging over orbit. This new...
A wide variety of fast ion driven instabilities are excited during neutral beam injection (NBI) in the National Spherical Torus Experiment (NSTX) [Nucl. Fusion 40, 557 (2000)] due to large ratio velocity Alfvén velocity, Vfast∕VAlfvén, and high beta. The Vfast∕VAlfvén ITER 39, 2137 (1999)] NSTX is comparable. modes can be divided into three categories: chirping energetic particle (EPM) frequency range 0 120kHz, toroidal eigenmodes (TAE) with a 50kHz 200kHz, compressional global (CAE GAE,...
After many years of fusion research, the conditions needed for a D–T reactor have been approached on Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)]. For first time unique phenomena present in plasma are now being studied laboratory plasma. The magnetic experiments to study plasmas using nearly equal concentrations deuterium and tritium carried out TFTR. At maximum power 10.7 MW, 39.5 MW neutral-beam heating, supershot discharge 6.7 high-βp following current rampdown....
Kinetic theory and experimental observations of a special class energetic particle driven instabilities called here beta-induced Alfvén-acoustic eigenmodes (BAAEs) are reported confirming, previous results [N. N. Gorelenkov et al., Plasma Phys. Controlled Fusion 49, B371 (2007)]. The kinetic is based on the ballooning dispersion relation where drift frequency effects retained. BAAE gaps recovered in theory. It shown that observed certain low-frequency DIII-D [J. L. Luxon, Nucl. 42, 614...
The effects of energetic ions on stability tearing mode are investigated by global kinetic/MHD hybrid simulations in a low beta tokamak plasma. kinetic counter circulating from the non-adiabatic response found to be strongly destabilizing while adiabatic stabilizing. net effect with both and contributions is destabilizing. On other hand, co-circulating calculated weakly stabilizing corresponding contribution for small ion beta. dependence beta, gyroradius, speed studied systematically...
Research on the National Spherical Torus Experiment, NSTX, targets physics understanding needed for extrapolation to a steady-state ST Fusion Nuclear Science Facility, pilot plant, or DEMO. The unique operational space is leveraged test theories next-step tokamak operation, including ITER. Present research also examines implications coming device upgrade, NSTX-U. An energy confinement time, τE, scaling unified varied wall conditions exhibits strong improvement of BTτE with decreased electron...
<title>Abstract</title> The chemical abundances of carbon-enhanced metal-poor (CEMP) stars contain plentiful information the elemental nucleosynthesis in early universe. Four CEMP-s were identified as single by monitoring their radial velocities. It hence challenges a longstanding assumption that this type star is formed binary system, where enriched heavy elements are transferred from companion. Here, we report an explanation influence enhanced 12C(α,γ)16O reaction inside these themselves,...
SUMMARY Phloridzin has various functions, including antioxidant properties and the treatment of diabetes, long been used in pharmaceutical physiological research. The glycosylation phloretin is a key step biosynthesis phloridzin. In this study, genome‐wide association study (GWAS) based on phloridzin content was applied, gene GhUGT88F3 for phloridzin‐specific identified cotton. A single‐base deletion haplotype I caused frameshift mutation, leading to premature translation termination...
Instabilities with frequency chirping in the range of Alfvén eigenmodes have been found domain 0.1% < ⟨βh⟩ 1% and vb||/vA ∼1 high energy neutral beam injection JT-60U. One instability a inside continuum spectrum appears its increases slowly to toroidicity induced eigenmode (TAE) gap on timescale an equilibrium change ( ≈ 200 ms). Other instabilities appear TAE their frequencies very quickly by 10-20 kHz 1-5 ms. During period when these fast sweeping (fast FS) modes occur, abrupt large...
The Tokamak Fusion Test Reactor (TFTR) (R. J. Hawryluk, to be published in Rev. Mod. Phys.) experiments on high-temperature plasmas, that culminated the study of deuterium–tritium D–T plasmas containing significant populations energetic alpha particles, spanned over two decades from conception completion. During design TFTR, key physics issues were magnetohydrodynamic (MHD) equilibrium and stability, plasma energy transport, impurity effects, reactivity. Energetic particle was given less...
Toroidal Alfvén eigenmodes are shown to be capable of inducing ripple trapping high-energy particles in tokamaks, causing intense localized particle loss. The effect has been observed TFTR [R. Hawryluk, Plasma Phys. Controlled Fusion 33, 1509 (1991)].