A5040501830- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Semiconductor materials and devices
- High voltage insulation and dielectric phenomena
- Atomic and Subatomic Physics Research
- Quantum and electron transport phenomena
- Quantum, superfluid, helium dynamics
- Physics of Superconductivity and Magnetism
- Nuclear reactor physics and engineering
- Advancements in Semiconductor Devices and Circuit Design
- Power Transformer Diagnostics and Insulation
- Integrated Circuits and Semiconductor Failure Analysis
- Gas Dynamics and Kinetic Theory
- Advanced Data Storage Technologies
- Magneto-Optical Properties and Applications
- Mental Health Research Topics
- Laser-induced spectroscopy and plasma
- Bioactive Compounds and Antitumor Agents
Columbia University
1994-2025
Lanzhou University
2024
Princeton Plasma Physics Laboratory
1993-1999
Princeton University
1993-1999
Irvine University
1996
University of Wisconsin–Madison
1993-1995
Massachusetts Institute of Technology
1995
Oak Ridge National Laboratory
1993-1995
Fusion Academy
1995
Fusion (United States)
1995
A new tokamak confinement regime has been observed on the Tokamak Fusion Test Reactor (TFTR) where particle and ion thermal diffusivities drop precipitously by a factor of \ensuremath{\sim}40 to neoclassical level for particles much less than value ions in region with reversed shear. This enhanced shear mode allows central electron density rise from 0.45 \ifmmode\times\else\texttimes\fi{} ${10}^{20}$ ${\mathrm{m}}^{\ensuremath{-}3}$ \ensuremath{\sim}1.2 ${T}_{i}\ensuremath{\sim}24$ keV...
A detailed comparison is made between the tearing-type modes observed in TFTR supershot plasmas and nonlinear, neoclassical pressure-gradient--driven tearing mode theory. Good agreement found on nonlinear evolution of single helicity magnetic islands $(m/n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3/2$, $4/3$, or $5/4$, where $m$ $n$ are poloidal toroidal numbers, respectively). The saturation these requires ${\ensuremath{\Delta}}^{\ensuremath{'}}<0$ (where...
Wall conditioning in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] by injection of lithium pellets into plasma has resulted large improvements deuterium–tritium fusion power production (up to 10.7 MW), Lawson triple product 1021 m−3 s keV), and energy confinement time 330 ms). The maximum current for access high-performance supershots been increased from 1.9 2.7 MA, leading stable operation at stored values greater than 5 MJ. amount on limiter...
Off-axis sawteeth are often observed in reversed magnetic shear plasmas when the minimum safety factor $q$ is near or below 2. Fluctuations with $m/n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2/1$ ( $m$ and $n$ poloidal toroidal mode numbers) appear before after crashes. Detailed comparison has been made between measured ${T}_{e}$ profile evaluation during crash a nonlinear numerical magnetohydrodynamics simulation. The good agreement observation simulation indicates that off-axis...
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...
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...
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....
Supershots in TFTR often suffer a performance deterioration characterized by gradual decrease of the DD fusion neutron yield and plasma stored energy after several hundred milliseconds auxiliary heating. The correlation between this development low m (the poloidal mode number), n toroidal number) MHD modes is studied through shot-to-shot comparisons statistical data analyses. A good observed appearance strong 3/2 4/3 macroscopic modes. magnetic island structures are using Mirnov ECE...
Drug craving in methamphetamine use disorder (MAUD) patients is influenced by various adverse psychological problems. This study adopted network analysis to investigate the interrelationships between correlates and drug identify critical pathways them. A total of 757 men with MAUD were recruited from a rehabilitation center southwest China. They completed self-report scales measure emotion regulation, depressive symptoms, childhood trauma, craving. We conducted assess interaction variables...
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...
The Tomamak Fusion Test reactor has performed initial high-power experiments with the plasma fueled nominally equal densities of deuterium and tritium. Compared to pure plasmas, energy stored in electron ions increased by \ensuremath{\sim}20%. These increases indicate improvements confinement associated use tritium possibly heating electrons \ensuremath{\alpha} particles created D-T fusion reactions.
The toroidal Alfvén eigenmodes (TAE) are calculated to be stable in the presently obtained deuterium–tritium plasmas Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Nucl. Res. 26, 11 (1984)]. However, core localized TAE mode can exist and is less than global modes. beam ion Landau damping radiative two main stabilizing mechanisms present calculation. In future experiments, alpha-driven modes predicted occur with a weakly reversed shear profile.
A new method for obtaining a transient ("pulse") electron heat diffusivity (Xe p) in the radial region 0.38 < r/a 0.56 TFTR [Plasm_l Phys.Controlled Nuc.Fus, Research 1, 51 (1986)] L-mode discharges is presented.Small temperature perturbations were caused by single bursts of • injected impurities which radiated and cooled plasma edge.An iron injection case laser ablation was found to be more definitive than supporting helium gas puff case.In this "cold pulse" method, we cortcentrate on...
The confinement and heating of supershot plasmas are significantly enhanced with tritium beam injection relative to deuterium in the Tokamak Fusion Test Reactor [Plasma Phys. Controlled 26, 11 (1984)]. global energy local thermal transport analyzed for fueled quantify their dependence on average mass hydrogenic ions. Radial profiles densities determined from D–T fusion neutron emission profile. inferred scalings isotopic quite strong, τE∝〈A〉0.85±0.20, τEthermal∝〈A〉0.89±0.20,...
A large “notch,” or non-monotonic feature, appears in measured toroidal velocity profiles of the carbon impurity Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled 26, 11 (1984)], centered near radius strongest ion temperature gradient. This is explained as a consequence radial momentum transport dominated by anomalous diffusion together with parallel heat friction on ions arising from hydrogenic neoclassical flow. The profile species predicted to be monotonic, measurements...
The toroidicity-induced Alfv\'en eigenmodes (TAE) are found to be stable in the Tokamak Fusion Test Reactor (TFTR) deuterium-tritium plasmas. dominant stabilizing mechanisms beam ion Landau damping and radiative damping. A core localized TAE mode is shown exist near center of plasma at small magnetic shear finite beta, which can destabilized by energetic alpha particles future TFTR DT experiments. With additional instability drive from fast minority ions powered cyclotron radio frequency,...
Several techniques were used to excite toroidal Alfven eigenmodes (TAE) in the Tokamak Fusion Test Reactor (TFTR) (Proc. 13th Int. Conf. on Plasma Physics and Controlled Nuclear Research Vol 1 (Vienna: IAEA, 1990) 9) at magnetic fields above 10 kG. These involved pellet injection raise plasma density, variation of current change energetic ion orbit q-profile, ICRF heating produce hydrogen ions velocities comparable with 3.5 MeV alpha particles created deuterium-tritium (d-t) fusion...
Alpha particle loss was measured during the TFTR DT experiments with a scintillator detector located at vessel bottom in ion Del B drift direction. The alpha to this consistent calculated first orbit over whole range of plasma current I=0.6-2.7 MA. In particular, rate per neutron given did not increase significantly fusion power up 10.7 MW, indicating absence any new 'collective' processes these
Experimental observations from TFTR of fast ion losses resulting the toroidicity induced Alfven eigenmode (TAE) and frequency mode (AFM) are presented. The AFM was driven by neutral beam ions, at low BT, TAE excited hydrogen minority cyclotron range frequencies (ICRF) tail ions higher BT. measurements indicate that loss rate varies linearly with amplitude for both modes, during activity can be significant, tens per cent input power lost in worst cases
Experiments with plasmas having nearly equal concentrations of deuterium and tritium have been carried out on TFTR. To date (September 1995), the maximum fusion power has 10.7 MW, using 39.5 MW neutral beam heating, in a supershot discharge 6.7 high beta P following current ramp-down. The density core plasma reached 2.8 MW/m3, exceeding that expected International Thermonuclear Experimental Reactor (ITER). energy confinement time tau E is observed to increase DT, relative D plasmas, by 20%...
An Alfven frequency mode (AFM) is very often seen in TFTR neutral beam heated plasmas as well ohmic plasmas. This quasi-coherent has so far only been on magnetic fluctuation diagnostics (Mirnov coils). A close correlation between the plasma edge density and activity (frequency amplitude) observed, which indicates that AFM an localized with r/a>0.85. No direct impact of this global performance or fast ion loss (e.g., alpha particles DT experiments) observed. not conventional TAE (toroidicity...
The Tokamak Fusion Test Reactor (TFTR) is a large tokamak which has performed experiments with 50:50 deuterium - tritium fuelled plasmas. Since 1993, TFTR produced about 1090 D T plasmas using 100 grams of and producing 1.6 GJ fusion energy. These have significant populations 3.5 MeV alphas (the charged product). research focused on alpha particle confinement, driven modes, heating studies. Maximum power production aided these studies, requiring simultaneously operation at high input energy...
Tearing-type modes are observed in most high confinement operation regimes the Tokamak Fusion Test Reactor (TFTR) [Nucl. 35, 1429 (1995)]. Three different methods used to measure magnetic island widths: external coils, internal temperature fluctuation from electron cyclotron emission (ECE) diagnostics and an experiment where plasma major radius is rapidly shifted (“Jog” experiments). A good agreement between three observed. Numerical analytic calculations of Δ′ (the tearing instability...
In the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] a substantial improvement in fusion performance has been realized by combining enhanced confinement due to tritium fueling with extensive conditioning of limiter lithium. This combination resulted not only significantly higher global energy times than have previously obtained high current supershots, but also highest central ratio thermonuclear output power input observed date.