A5034173574- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Fusion materials and technologies
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Dust and Plasma Wave Phenomena
- Nuclear reactor physics and engineering
- Terahertz technology and applications
- Ocean Waves and Remote Sensing
- Nuclear Physics and Applications
- GNSS positioning and interference
- Physics of Superconductivity and Magnetism
- Tropical and Extratropical Cyclones Research
- Advanced Chemical Physics Studies
- High voltage insulation and dielectric phenomena
- High-pressure geophysics and materials
- Electrohydrodynamics and Fluid Dynamics
- Combustion and Detonation Processes
- Electrostatic Discharge in Electronics
- Particle Detector Development and Performance
- Geophysics and Gravity Measurements
- Real-time simulation and control systems
University of Science and Technology of China
2016-2025
Chinese Academy of Sciences
2020-2024
Southwestern Institute of Physics
2023
University of Saskatchewan
2020-2022
Institute of Plasma Physics
2020-2022
University of California, Los Angeles
2017-2022
Hefei University of Technology
2018
Evidence of a nonlinear transition from mitigation to suppression the edge localized mode (ELM) by using resonant magnetic perturbations (RMPs) in EAST tokamak is presented. This first demonstration ELM with RMPs slowly rotating plasmas dominant radio-frequency wave heating. Changes topology after are indicated gradual phase shift plasma response field linear magneto hydro dynamics modeling result vacuum one and sudden increase three-dimensional particle flux divertor. The threshold depends...
Full suppression of type-I edge localized modes (ELMs) using n = 4 resonant magnetic perturbations (RMPs) as planned for ITER has been demonstrated the first time (n is toroidal mode number applied RMP). This achieved in EAST plasmas with low input torque and tungsten divertor, target plasma these experiments chosen to be relevant Q 10 operational scenario, thus also addressing significant scenario issues ITER. In lowest neutral beam injection (NBI) around TNBI ∼ 0.44 Nm, which extrapolates...
A Doppler reflectometer system has recently been installed in the Experimental Advanced Superconducting (EAST) Tokamak. It includes two separated systems, one for Q-band (33–50 GHz) and other V-band (50–75 GHz). The optical consists of a flat mirror parabolic which are optimized to improve spectral resolution. synthesizer is used as source 20 MHz single band frequency modulator get differential heterodyne detection. Ray tracing simulations calculate scattering location perpendicular wave...
Doppler backscattering system can measure the perpendicular velocity and fluctuation amplitude of density turbulence with intermediate wavenumber. An eight-channel has been installed in Experimental Advanced Superconducting Tokamak (EAST), which probe eight different radial locations simultaneously by launching fixed frequencies (55, 57.5, 60, 62.5, 67.5, 70, 72.5, 75 GHz) into plasma. The quasi-optical consists circular corrugated waveguide transmission, a parabolic mirror, rotatable mirror...
By analyzing large quantities of discharges in the unfavorable ion B ×∇B drift direction, I-mode operation has been confirmed EAST tokamak.During L-mode to transition, energy confinement a prominent improvement by formation high-temperature edge pedestal, while particle remains almost identical that L-mode.Similar with observation on other devices, E r profiles obtained eight-channel Doppler backscattering system (DBS8) [1] show deeper well than L-mode.And weak coherent mode (WCM) frequency...
High-β_{θe} (a ratio of the electron thermal pressure to poloidal magnetic pressure) steady-state long-pulse plasmas with steep central temperature gradient are achieved in Experimental Advanced Superconducting Tokamak. An intrinsic current is observed be modulated by turbulence driven gradient. This turbulent generated countercurrent direction and can reach a maximum 25% bootstrap current. Gyrokinetic simulations experimental observations indicate that mode (ETG). The dominant mechanism for...
Abstract Geodesic acoustic mode (GAM) is the finite frequency counterpart of zonal flow in toroidal plasmas, which could be excited by and regulate turbulence. This article reports a stationary eigenmode GAM at inner side edge radial electric field contributing to an extreme high confinement plasma with H98>1.3. Such observed exclusively vicinity pedestal top, but not within pedestal, represents previously unreported phenomenon. The bicoherence analysis demonstrates robust interaction...
A novel all-fiber optic current sensor (FOCS) is designed specifically for the measurement of large transient currents based on Faraday effect. reciprocal symmetric structure incorporated into optical sensing loop, and dependent phase demodulation achieved by using a passive fiber coupler homodyne detection scheme. This design offers several advantages, including structural simplicity, high voltage insulation, low noise, linearity, excellent frequency response, highly suitable use in any...
Abstract The tearing mode, a large-scale MHD instability in tokamak, typically disrupts the equilibrium 
magnetic surfaces, leads to formation of magnetic islands, reduces core electron temperature 
and density, thus resulting significant energy losses and may even cause discharge termination. 
This process is unacceptable for ITER. Therefore, accurate identification island 
in real time crucial effective control mode ITER future. In this study, 
based...
Abstract The five-channel tunable W-band Doppler reflectometry (DR) installed in
the Experimental Advanced Superconducting Tokamak (EAST) [Rev. Sci. Instrum.90,
024704] has been upgraded. signal launching and receiving circuits have been
separated in order to circumvent the reflection of W- band filter on launching
microwave, thereby reducing background noise from 40 mV 5 . The
frequency interval between adjacent channels increased 400 M Hz...
Abstract An E-band (60-90 GHz) tunable ten-channel BackScattering and one-channel Forward-Scattering integrated Doppler reflectometer with X-mode polarization has been installed on the O port of Experimental Advanced Superconducting Tokamak (EAST). This system can launch 16 fixed microwave beams in range 60-90 GHz an interval 2 into plasma, 10 probing signals are selected by employing a reference signal multiple filters. It measure turbulence at different radial locations simultaneously. In...
Abstract This paper reports the recent observation of a weakly coherent mode (WCM) within conventional reflectometer on EAST and successfully determines its poloidal wavenumber range. During transition from L-mode to I-mode, line-averaged density remains nearly unchanged while significant change is observed in electron cyclotron emission (ECE) signals at boundary. The difference between for two channels edge increased, coinciding with appearance WCM simultaneous rise boundary temperature....
Here we report the experimental analysis on low-lignl/ig (mostly lignl/ig = 1, sometimes 2) magnetic coherent mode (MCM) at a characteristic frequency 20−60 kHz, which has been frequently observed in various H-mode discharges EAST. This can be easily identified fluctuations measured by fast Mirnov coils mounted vacuum vessel wall, but is detected local measurements of edge electrostatic only when sufficiently strong. The apperance of MCM summarized covering broad ranges discharge...
A 5-channel Doppler backscattering system has been designed and installed in the Experimental Advanced Superconducting Tokamak (EAST). Through an I/Q-type double sideband modulator a frequency multiplier, array of finely spaced (Δf = 400 MHz) frequencies that span 1.6 GHz created. The center bandwidth is tunable within range 75-97.8 GHz, which covers most W band (75-110 GHz). incident angle can be adjusted from −4° to 12°, wavenumber 4-15 cm−1 with resolution Δk/k ≤ 0.35. Ray tracing used...
A strong relationship between the fishbone instability and internal transport barrier (ITB) formation has been found on Experimental Advanced Superconducting Tokamak (EAST) in high βN ELMy H-mode discharges. ITB always appears after instability, disappears when grows to a certain extent. Hybrid simulations with global kinetic-magnetohydrodynamic (MHD) code M3D-K have carried out investigate linear stability non-linear dynamics of beam-driven instabilities these shots. The simulation results...
Sixty-five discharges have been confirmed as I-mode after searching the EAST database from 2016 to 2018, and some additional were obtained in 2019. The regime features no edge localized modes (ELMs), high energy confinement, a steep temperature pedestal, while particle confinement remains at L-mode levels. has over small parameter space (BT = 2.4 – 2.7 T, Ip 0.4 0.6 MA, q95 4 6) using configuration with drift away active X-point. Most of are dominated by lower hybrid wave (LHW) heating. In...
A reproducible stationary improved confinement mode (I-mode) has been achieved recently in the Experimental Advanced Superconducting Tokamak (EAST), featuring good without particle transport barrier.The microscopic mechanism of sustaining I-mode, based on coupling between turbulence transitions and edge temperature oscillation, discovered for first time.A radially localized ring oscillation (ETRO) with azimuthally symmetric structure (n = 0, m 0) identified it is accompanied by alternating...
A toroidal Alfvén eigenmode (TAE) excited by barely trapped energetic electrons during the application of a static magnetic perturbations (MPs) is observed for first time in tokamak ohmic heating plasmas. This TAE appears when current n = 2 MPs exceeds threshold value, at which forced reconnection happens. Here, mode number. located near plasma edge, agrees with calculation gap. It propagates ion diamagnetic direction and has dominant number 2. The frequency consistent precessional energy...
Abstract The evolutions of MHD instability behaviors and enhancement both electrostatic electromagnetic turbulence towards the plasma disruption have been clearly observed in HL-2A plasmas. Two types disruptive discharges investigated for similar equilibrium parameters: one with a distinct stage small central temperature collapse ( $$\sim$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>∼</mml:mo> </mml:math> 5–10%) around 1 millisecond before thermal quench (TQ), while...
Abstract Quasi-periodic pedestal burst instabilities (PBIs), featuring alternative turbulence suppression and bursts, have been clearly identified by various edge diagnostics during I-mode to H-mode transition in the EAST Tokamak. The radial distribution of phase perturbation caused PBI shows that is localized pedestal. Prior each PBI, a significant increase density gradient close top can be distinguished, then generated, accompanied relaxation profile, induces an outward particle flux....
Density pump-out has been observed on the experimental advanced superconducting tokamak under conditions of mitigated or totally suppressed edge localized modes with n = 2 external resonant magnetic perturbation (RMP), associated decreased core density and degradation particle confinement. In order to investigate transport during RMP induced pump-out, modulation using supersonic molecular beam injection is performed obtain coefficients. The results show that diffusive coefficient becomes...
Dedicated experiments focusing on the influence of lower hybrid waves (LHWs) edge-localized modes (ELMs) were first performed during 2012 experimental campaign EAST, via modulating input power LHWs in high-confinement-mode (H-mode) plasma mainly sustained by ion cyclotron resonant heating. Natural ELMs are effectively mitigated (ELM frequency increases, while its intensity decreases dramatically) as LHW is applied, observed over a fairly wide range current or edge safety factor. By scanning...
Abstract A compact torus injection system, KTX-CTI, has been developed for the planned experiments on Keda Torus eXperiment (KTX) reversed field pinch (RFP) device to investigate physics and engineering issues associated with interaction between a (CT) RFP. The key interests include fueling directly into reactor center, confinement improvement, of momentum helicity RFP discharges. CT velocity mass have measured using multichannel optical fiber interferometer, first time evolution density...
The magnetic fluctuations of geodesic acoustic modes (GAMs) have been investigated using a Doppler backscattering system and Mirnov probes during ion cyclotron resonance heating lower hybrid wave in the edge plasma experimental advanced superconducting tokamak, component GAM was observed. frequency has clear relationship with electron temperature, mode numbers poloidal structure are approximately m=2 (sin (2θ)) n = 0. A more detailed investigation shows that maximum values amplitude field...