A5075101983- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Solar and Space Plasma Dynamics
- Dust and Plasma Wave Phenomena
- Physics of Superconductivity and Magnetism
- Advanced Database Systems and Queries
- Optical Systems and Laser Technology
- Advanced Optical Sensing Technologies
- Earthquake Detection and Analysis
- Data Visualization and Analytics
- Laser-induced spectroscopy and plasma
- Advanced Text Analysis Techniques
- Iterative Learning Control Systems
- Atomic and Molecular Physics
Nanjing University
2025
Southwestern Institute of Physics
2011-2023
University of British Columbia
2023
Dalian University of Technology
2022
The features of ion and electron fishbone instabilities have been investigated during neutral beam injection (NBI) cyclotron resonance heating (ECRH) on HL-2A. Some new phenomena, such as frequency jumps V-font-style sweeping, presented in the paper. Three kinds i-fishbones, including hybrid sawtooth–fishbone (sawbone), run-on classical fishbone, identified NBI. During high power ( P ECRH > 0.7 MW) ECRH, experimental results indicate that e-fishbone frequencies are higher than those low...
Abstract Density profiles in the pedestal region (H-mode) are measured HL-2A and characteristics of density described. Cold particle deposition by supersonic molecular beam injection (SMBI) within is verified. Edge-localized mode (ELM) mitigation SMBI into H-mode demonstrated relevant physics elucidated. The sensitivity effect to pressure duration studied. Following SMBI, ELM frequency increases amplitude decreases for a finite duration. Increases <?CDATA $f_{{\rm ELM}}^{{\rm SMBI}} /f_{{\rm...
Abstract Ion internal transport barriers (iITBs) are first observed in neutral beam injection (NBI) heated plasmas at the HL-2A tokamak. The position of barrier foot, stationary state, coincides with q = 1 surface within its uncertainty measurement. iITBs can develop more easily beginning NBI heating. Also, unstable for sawtooth plasma. Simulations reveal that thermal diffusivity ions ( χ i ) inside be as low neoclassical level. It is flow shear iITB state reaches level required suppressing...
Typical ELMy H-mode discharges have been achieved on the HL-2A tokamak with combined auxiliary heating of NBI and ECRH. The minimum power required is about 1.1 MW at a density 1.6 × 1019 m−3 increases decrease in density, almost independent launching order ECRH heating. energy loss by each edge localized mode (ELM) burst estimated to be lower than 3% total stored energy. At frequency typically 400 Hz, confinement time only marginally reduced ELMs. supersonic molecular beam injection fuelling...
A 32/64-channel charge exchange recombination spectroscopy (CXRS) diagnostic system is developed on the HL-2A tokamak (R = 1.65 m, a 0.4 m), monitoring plasma ion temperature and toroidal rotation velocity simultaneously. high throughput spectrometer (F/2.8) pitch-controlled fiber bundle enable temporal resolution of up to 400 Hz. The observation geometry an optimized optic highest radial ∼1 cm at edge. CXRS monitors carbon line emission (C VI, n 8-7, 529.06 nm) whose Doppler broadening...
Strong m = 1 MHD activities are observed in the HL-1M tokamak during off-axis electron cyclotron resonance heating (ECRH) when location is placed just outside q surface at high-magnetic-field side of magnetic surface. Addition lower-hybrid waves to ECRH significantly enhances excitation, but alone cannot excite or sustain mode. This result a clear demonstration suprathermal trapped effect on instability because absence energetic ions plasma.
Two groups of frequency sweeping modes are observed and interpreted in the HL-2 A plasmas with qmin ~ 1. The tokamak simulation code calculations indicate presence a reversed shear q-profile during existence these modes. mode frequencies lie between TAE BAE frequencies, i.e. ωBAE 1 nqmin − m > 0, another group characterized by up-sweeping drop, owing to < 0 before sawtooth crash. kinetic Alfven eigenmode analysis supports that down-sweeping reverse eigenmodes (KRSAEs), RSAEs, which exist...
Experimental observation and theoretical analysis are presented for the nonlinear mode couplings between shear Alfven wave magnetic island. In sub-Alfven frequency range, two kind axi-symmetry activities with n = 0 have been observed during NBI on HL-2A. One has identified, belongs to EGAM. Another is found first time, its lies in range of TAE frequency. The Fourier bicoherence suggests these modes generated by coupling via decay process eigenmodes low-frequency MHD modes. experimental...
In this paper, an overview of the magnetohydrodynamic instabilities induced by energetic electrons on HL-2A is given and some new phenomena with high-power electron cyclotron resonance heating (ECRH) are presented. A toroidal Alfvén eigenmode frequency from 200 to 350 kHz identified during powerful ECRH. lower range 10 35 kHz, which in beta-induced range, coexistence multi-mode found ECRH for first time. The spectra become wide when power sufficiently high. frequencies modes increase much...
We report an experimental result on the stabilization of energetic–ion driven internal kink mode (ion fishbone) by electron cyclotron resonance heating (ECRH), observed for first time in a toroidal plasma. The asserts itself resistive branch close to marginal stability point. resulting fishbone depends not only injected power but also radial deposition location ECRH, and instability can be completely suppressed when ECRH exceeds certain threshold. Analysis dispersion relation, including...
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 Recent experimental results that are associated with the core-localized (i.e. normalized radius <?CDATA $\rho =r/a<0.5$ ?> <?MML <mml:math><mml:mstyle displaystyle='false'><mml:mi>ρ</mml:mi><mml:mo>=</mml:mo><mml:mi>r</mml:mi><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:mi>a</mml:mi><mml:mo><</mml:mo><mml:mn>0.5</mml:mn></mml:mstyle></mml:math> ) Alfvénic modes in HL-2A neutral beam injection (NBI) plasmas weak magnetic shears reported. In different plasma parameter...
High-βp scenario addresses needs for an attractive tokamak fusion reactor design, where βp is the normalized plasma poloidal beta. experiments have been performed during recent years in HL-2A tokamak. The high-performance region realized by integration of internal and external transport barriers which are dubbed as ITBs ETBs, namely, double (DTBs), with high-power NBI heating. Generally, ITB forms becomes strong after injection on HL-2A. Subsequently, edge ion temperature toroidal rotation...
Toroidal Alfvén eigenmodes (TAEs) driven by energetic electrons have been observed first during high-power electron cyclotron resonant heating and neutral beam injection on HL-2A. The mode frequencies are in a wide range of 170–370 kHz proportional to the velocity. toroidal number is confirmed as n = 4. According calculated results from code, there exists core localized TAE with poloidal numbers m 4 5 at ρ∼0.35, frequency close experimental observation. Besides, radial structures obtained....
Fishbone instability excited by energetic electrons during electron cyclotron resonant heating (ECRH) is identified on HL-2A. With high-power ECRH, periodic frequency jump phenomena are observed soft x-ray arrays. Soft tomography shows that the poloidal and toroidal mode numbers 1/1 2/2 with jump. There an ECRH power threshold for phenomena, which generally about 0.9 MW. The frequencies of two modes increase power. Experiments show trapped particles dominant in low-density plasma....
A tokamak scenario with q(0) close to 1 has been achieved on HL-2A tokamak, which is an internal transport barrier (ITB) at low central shear or a steady-state ITB combined H-mode edge barrier. In this scenario, the formation of steep ion temperature profile observed be closely linked q = magnetic surface and magnetohydrodynamic (MHD) activities around it, such as long-lived mode (LLM) fishbone activities. Experimental evidence simulation analysis suggest that can induce poloidal flow,...
The operation conditions have been improved via developing new technologies and improving the hardware on HL-2A tokamak in recent years. ECRH system has upgraded to 3 MW/68 GHz, supersonic molecular beam injection (SMBI) fuelling technique developed further, clusters can be formed SMB by cooling gas around liquid nitrogen temperature, so that deeper penetration achieved. Moreover, there are about 30 kinds of diagnostics measure plasma parameters. These diagnostic systems include magnetics,...
A 7-channel motional Stark effect polarimeter based on four polarizers and a spectrometer has been developed in the HL-2A tokamak, which is first time successful utilizing this kind of tokamak. The accuracy angle can reach ±0.25° calibration experiments. Pilot experiments measuring magnetic pitch have successfully carried out weak plasma discharge with toroidal field ~1.3 T beam energy ~25 keV/amu. angles are obtained for 7 spatial points covering 24 cm along major radius resolution 40 ms;...
The operation conditions have been improved via developing new technologies and improving the hardware on HL-2A tokamak in recent years. ECRH system has upgraded to 3 MW/68 GHz, supersonic molecular beam injection (SMBI) fuelling technique developed further, clusters can be formed SMB by cooling gas around liquid nitrogen temperature, so that deeper penetration achieved. Besides, there are about 30 kinds of diagnostics measure plasma parameters. These diagnostic systems include magnetics,...
Many online tabular datasets are maintained in centralized repositories and annotated with descriptive tags. These tags helpful for data practitioners to search understand tables. However, manually annotating new tables added a large repository is expensive may be inconsistent. In this extended abstract, we propose tag inference methods implement an interactive visual explainer prototype visualize table respect help human user examine whether recommended suitable the table.