A5085160002- Magnetic confinement fusion research
- Astrophysics and Cosmic Phenomena
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Fusion materials and technologies
- Superconducting Materials and Applications
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- GNSS positioning and interference
- Particle accelerators and beam dynamics
- Fluid Dynamics and Turbulent Flows
- Plasma Diagnostics and Applications
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
- Particle Dynamics in Fluid Flows
- Advanced materials and composites
- High-Temperature Coating Behaviors
- Metal and Thin Film Mechanics
- Astronomical Observations and Instrumentation
- Radio Wave Propagation Studies
- Cyclone Separators and Fluid Dynamics
- Astrophysics and Star Formation Studies
Chongqing University of Technology
2024
Xinjiang Astronomical Observatory
2023
Chinese Academy of Sciences
2023
Shenzhen University
2022
Princeton Plasma Physics Laboratory
2017-2019
Princeton University
2018
University of California, San Diego
2014-2016
Center for Urban Waters
2015
University of Colorado Boulder
2014
San Diego Association of Governments
2014
TRANSP simulations are being used in the OMFIT workflow manager to enable a machine-independent means of experimental analysis, postdictive validation, and predictive time-dependent on DIII-D, NSTX, JET, C-MOD tokamaks. The procedures for preparing input data from plasma profile diagnostics equilibrium reconstruction, as well processing heating current drive sources assumptions about neutral recycling, vary across machines, but streamlined by using common manager. Settings simulation...
We report experimental studies demonstrating a controlled transition to fully developed broadband turbulence in an argon helicon plasma linear device. show the detailed dynamics during from nonlinearly coupled but distinct eigenmodes at low magnetic fields larger fields. As field (B) is increased B ∼ 40 mT, initially we observe slow smooth changes of system (to 140 mT), followed by sharp (within ∼10 mT) centrally peaked narrow density profiles, strong edge potential gradients and pronounced...
Recent experiments on EAST have achieved the first long pulse H-mode (61 s) with zero loop voltage and an ITER-like tungsten divertor, demonstrated access to broad plasma current profiles by increasing density in fully-noninductive lower hybrid current-driven discharges. These discharges reach wall thermal particle balance, exhibit stationary good confinement (H98y2 ~ 1.1) low core electron transport, are only possible optimal active cooling of armors. In separate experiments, was...
Systematic experimental and modeling investigations on DIII-D show attractive transport properties of fully non-inductive high βp plasmas. Experiments that the large-radius internal barrier (ITB), a key feature providing excellent confinement in regime, is maintained when scenario extended from q95 ∼ 12 to 7 rapid near-zero toroidal rotation. The robustness versus rotation was predicted by gyrofluid showing dominant neoclassical ion energy even without E × B shear effect. physics mechanism...
Varying the neutral beam injection (NBI) mix reveals a clear pedestal-top rotation threshold for edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs). Guided expectations RMP penetration mechanism, is found to correspond critical radius zero-crossing. No such observed electron perpendicular amount and ratio of power in different NBI source geometries (termed mix) also that can be crossed at widely varying total injected torques. Computing local torque density edge,...
Helicon plasmas are typically associated with a core, radially localized central area of strong ion light emission. Here, we investigate the role electrostatic instabilities that lead to formation classic blue core. We show helicon plasma can also occur without distinct In these conditions, is dominated by low-frequency resistive drift wave (RDW) propagating in electron diamagnetic direction. When intense sharp core present, new global equilibrium state achieved where three separated exist...
Experimental and modeling investigations on the DIII-D EAST tokamaks show attractive transport stability properties of fully noninductive, high poloidal-beta (βP) plasmas, their suitability for steady-state operating scenarios in ITER CFETR. A key feature high-βP regime is large-radius (ρ > 0.6) internal barrier (ITB), often observed all channels (ne, Te, Ti, rotation), responsible both excellent energy confinement quality properties. Experiments have shown that, with a ITB, very βN βP...
We report the observation of a transport bifurcation that occurs by spontaneous self-organization drift-wave and shear flow system in linear plasma device. As we increase magnetic field above threshold (BCr = 1200 G), global transition occurs, with steepening mean density ion pressure profiles, onset strong E×B shearing, reduction turbulence, improved turbulent radial particle transport. An abrupt appears graph flux versus gradient. Hysteresis gradient further confirms this bifurcation. The...
The hybrid regime with beta, collisionality, safety factor and plasma shape relevant to the ITER steady-state mission has been successfully integrated ELM suppression by applying an odd parity n = 3 resonant magnetic perturbation (RMP). Fully non-inductive hybrids in DIII-D tokamak high beta ( ⩽ 2.8%) confinement (H98y2 1.4) similar have achieved zero surface loop voltage for up two current relaxation times using efficient central drive from ECCD NBCD. RMP causes surprisingly little increase...
We report a net inward, up-gradient turbulent particle flux in cylindrical plasma when collisional drift waves generate sufficiently strong sheared azimuthal flow that drives positive (negative) density fluctuations up (down) the background gradient, resulting steepening of mean gradient. The results show existence saturation mechanism for drift-turbulence driven flows can cause transport and profile steepening.
Experiments using Resonant Magnetic Perturbations (RMPs), with a rotating n = 2 toroidal harmonic combined stationary 3 harmonic, have validated predictions that divertor heat and particle flux can be dynamically controlled while maintaining Edge Localized Mode (ELM) suppression in the DIII-D tokamak. Here, is mode number. ELM over one full cycle of RMP was mixed static field has been achieved. Prominent splitting on outer observed during by RMPs low collisionality regime DIII-D. Strong...
Edge localized mode (ELM) suppression has been achieved in the DIII-D tokamak using mixed toroidal and 3 harmonic resonant magnetic perturbations (RMPs). Here is number. It observed that RMPs lower threshold current for ELM compared to single case. The decreased suggests offer a better path control. error field effect studied by superimposing correction upon phase scan, which shows it possible suppress correct simultaneously. plasma response measured sensors plays key role RMPs. A nonlinear...
Applications of a metallic material highly depend on its mechanical properties, which greatly the material’s grain sizes. Reducing sizes by severe plastic deformation is one efficient approaches to enhance properties material. In this paper, equal channel angular pressing (ECAP) will be reviewed illustrate effects refinement some common materials such as titanium alloys, aluminum and magnesium alloys. ECAP process, can processed severely repeatedly in designed mold accumulate large amount...
We show that the degradation of fast-ion confinement in steady-state DIII-D discharges is quantitatively consistent with predictions based on effects multiple unstable Alfven eigenmodes beam-ion transport. Simulation and experiment increasing radius where magnetic safety factor has its minimum effective minimizing This favorable for achieving high performance operation future reactors. A comparison between experiments a critical gradient model, which only equilibrium profiles were used to...
Resonant magnetic perturbations (RMPs) are a leading method for edge localized modes (ELMs) Control in fusion plasmas. However they can also cause rapid degradation energy confinement. In this paper we show that the confinement low collisionality ( < 0.3) DIII-D ITER similar shape (ISS) plasmas often recovers after several times RMP amplitudes up to threshold ELM suppression. Immediately following application of RMP, plasma stored decreases proportion decrease line-averaged density during...
We use multiple-tip Langmuir probes and fast imaging to unambiguously identify study the dynamics of underlying instabilities during controlled route fully-developed plasma turbulence in a linear magnetized helicon device. measure radial profiles electron temperature, density potential; from which we compute growth rates instabilities, cross-phase between potential fluctuations, Reynold's stress, particle flux, vorticity, time-delay estimated velocity, etc. Fast complements 1D probe...
Abstract The importance of Very Long Baseline Interferometry (VLBI) for pulsar research is becoming increasingly prominent and receiving more attention. In this paper, we present pathfinding observation results with the Chinese VLBI Network (CVN) incorporating Five-hundred-meter Aperture Spherical radio Telescope (FAST). On MJD 60045 (April 11th, 2023), PSRs B0919+06 B1133+16 were observed phase-referencing mode in L-band using four telescopes (FAST, TianMa, Haoping Nanshan) correlated...
Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields high-purity low toroidal rotation, 4He plasmas have resulted Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained with zero net input torque near the L–H power threshold either electron cyclotron resonant heating (ECRH) or balanced co- counter-Ip neutral beam injection (NBI) resulting conditions equivalent to those expected ITER's non-active operating phase. In low-power ECRH H-modes,...
It is believed that dual active galactic nuclei (dual AGN) will form during galaxies merge. Studying dual-AGN emission can provide valuable insights into galaxy merging and evolution. To investigate parsec-scale radio properties, we observed eight components of four selected systems using the Very Long Baseline Array (VLBA) at 5 GHz in multiple-phase-center mode. Among them, two compact components, labeled J0051+0020B J2300-0005A, were detected clearly on parsec scales for first time....
The importance of Very Long Baseline Interferometry (VLBI) for pulsar research is becoming increasingly prominent and receiving more attention. In this paper, we present pathfinding observation results with the Chinese VLBI Network (CVN) incorporating Five-hundred-meter Aperture Spherical radio Telescope (FAST). On MJD 60045 (April 11th, 2023), PSRs B0919+06 B1133+16 were observed phase-referencing mode in L-band using four telescopes (FAST, TianMa, Haoping Nanshan) correlated binning...
Abstract Powerful relativistic jets in active galactic nuclei (AGN) are believed to be originated from the accretion of material onto supermassive black hole (SMBH) 1 . The nearby radio galaxy M87 is one best examples this phenomenon, and recent detection a black-hole shadow with Event Horizon Telescope provided compelling evidence for paradigm 2 However, whether central SMBH has spin or not, fundamental parameter BH along mass, remains unconstrained by observations since appearance photon...