A5060916647- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Physics of Superconductivity and Magnetism
- Atomic and Subatomic Physics Research
- Gyrotron and Vacuum Electronics Research
- Nuclear reactor physics and engineering
- GNSS positioning and interference
- Dust and Plasma Wave Phenomena
- Cavitation Phenomena in Pumps
- Building Energy and Comfort Optimization
- High-Energy Particle Collisions Research
- Cyclone Separators and Fluid Dynamics
- Radar Systems and Signal Processing
- Phase Change Materials Research
- Statistical Distribution Estimation and Applications
- Tropical and Extratropical Cyclones Research
- Meteorological Phenomena and Simulations
- Magnetic properties of thin films
Zhejiang University of Technology
2025
Southwestern Institute of Physics
2015-2024
Huazhong University of Science and Technology
2024
Xihua University
2015-2017
A novel 16-channel fixed frequency Doppler backward scattering (DBS) reflectometer system has been developed on the HL-2A tokamak. This is based filter-based feedback loop microwave source (FFLMS) technique, which lower phase noise and power variation compared with present tunable generation comb array techniques [J. C. Hillesheim et al. Rev. Sci. Instrum. 80, 083507 (2009) W. A. Peebles 81, 10D902 (2010)]. The DBS comprised of four × four-frequency transmitters direct quadrature...
The radial profiles of perpendicular flows in the presence magnetic island were firstly measured HL-2A tokamak by hopping work frequency Doppler backward scattering reflectometer system along with a two-dimensional electron cyclotron emission imaging diagnostic identifying locations. It has been observed that across O-point cut flow is quite small at center and strongly enhanced around boundary island, resulting large increase shear outer half while X-point almost flat whole region....
The oscillations of poloidal plasma flows induced by radially sheared zonal are investigated newly developed correlation Doppler reflectometers in the HL-2A tokamak. non-disturbing diagnostic allows one to routinely measure rotation velocity turbulence, and hence radial electric field fluctuations. With reflectometers, a three-dimensional spatial structure geodesic acoustic mode (GAM) is surveyed, including symmetric feature toroidal Er fluctuations, dependence GAM frequency on temperature...
In HL-2A and J-TEXT ohmic confinement regimes, an electrostatic turbulence with quasi-coherent characteristics in spectra of density fluctuations was observed by multi-channel microwave reflectometers. These modes (QCMs) were detectable a large plasma region (r/a∼0.3−0.8). The characteristic frequencies QCMs the range 30–140 kHz. mode is rotated electron diamagnetic direction. plasmas QCMs, trapped (TEM) predicted to be unstable gyrokinetic simulations. combined experimental results show...
ABSTRACT In addressing the complexities associated with conveyance of solid–liquid two‐phase flow by a self‐priming pump in field irrigation and drainage, this study numerically investigates impact three typical solid phase properties on hydraulic performance pump, employing Mixture multiphase model. Concurrently, utilizing discrete model (DPM), influence operational speed working condition rate wear passage components' walls is also examined. The findings indicate that order significance...
Multi-scale interactions have been observed recently in the HL-2A core NBI plasmas, including synchronous coupling between kink mode and tearing mode, nonlinear couplings of TAE/BAE TM near surface, AITG/KBM/BAE high-frequency turbulence. Experimental results suggest that several can exist simultaneously, Alfvenic fluctuations an important contribution to turbulence spectra, reveal electromagnetic character. via modulation process maybe enhance plasma transport trigger sawtooth-crash onset.
In HL-2A, the characteristics of edge plasma instabilities and their effects on dynamical evolution pedestal in H-mode plasmas have been investigated. region with steep pressure gradient, a quasi-coherent mode (QCM) has observed density fluctuations frequency range 50–100 kHz. It appears during localized (ELM)-free period after L–H transition prior to first ELM. A threshold gradient identified for excitation this mode. The QCM can also be inter-ELM periods. is excited early period,...
Modulation of turbulent electron temperature fluctuations () and density by an m/n = 1/1 tearing mode island was observed in the core plasma region HL-2A tokamak. High spatiotemporal resolution two-dimensional images show first evidence that turbulence modulation occurs only when width exceeds a certain threshold value ( cm) is localized merely inner area due to significant alteration local profiles drives. Evidence also reveals for large islands spreading takes place across region. The...
Impurity seeding experiments in ELMy H-mode plasmas by using supersonic molecular beam injection (SMBI) have been performed the HL-2A tokamak. Besides pure impurity gas (neon, argon), impurities mixed with main ion fuelling different ratios were seeded into plasma. It has observed that ELM behavior and plasma confinement are very sensitive to ratio. For 30% Ne seeding, large ELMs replaced high frequency bursts (HFBs), which higher smaller amplitude compared peak heat load on divertor plate...
Abstract We report the first interpretation of ion cyclotron emission (ICE) based on frequency variation in HL-2A tokamak experiments. The measured frequencies ICE are concentrated around frequency, while simultaneously exhibiting a linear scaling with Alfvén velocity. A fully kinetic simulation demonstrates that low fast concentration, approaches wave dispersion relation. relation is similar to “equatorial noise” inner magnetosphere, providing new opportunities for comparing physical model...
Abstract Electron Cyclotron Emission Imaging (ECEI) is a critical diagnostic tool for measuring two-dimensional electron temperature fluctuations. The optical system, key component of the ECEI diagnostic, determines spatial resolution, field view, and imaging performance In this study, comprehensive laboratory tests characterizations including Local Oscillator (LO) coupling optics Radio Frequency (RF) receiving optics, were conducted to ensure optimal during plasma discharge experiments....
Abstract The effect of lower hybrid current drive (LHCD) on edge velocity shear and turbulence in the HL-2A tokamak has been investigated. Experimental results demonstrate that LHCD leads to an increase at both inner outer layers, with magnitude increment found be proportional applied power. This enhancement is primarily attributed changes plasma pressure gradient induced by heating wave. In addition, also modifies edge, it observed higher wavenumbers exhibits a clear LHCD, whereas shows no...
A multichannel microwave interferometer system has been developed on the HL-2A tokomak. Its working frequency is well designed to avoid fringe jump effect. Taking structure of into account, its antennas are installed in horizontal direction, i.e. one launcher high field side (HFS) and four receivers low (LFS). The fan-shaped measurement area covers those regions where magnetohydrodynamics (MHD) instabilities active. heterodyne technique contributes temporal resolution (1 μs). It possible for...
Over the past several years, high-
Abstract Improved energy confinement mode (I-mode) has been observed on the HL-2A tokamak. The I-mode features an edge transport barrier (ETB) in electron temperature and a low like density. A weakly coherent (WCM) is region with frequency of <?CDATA $f\sim 60{-}160$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>f</mml:mi> <mml:mo>∼</mml:mo> <mml:mn>60</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> </mml:mrow> <mml:mn>160</mml:mn> </mml:math> kHz poloidal...
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...
We report the first experimental evidence of Alfvenic ion temperature gradient (AITG) modes in HL-2A Ohmic plasmas. A group oscillations with $f=15-40$ kHz and $n=3-6$ is detected by various diagnostics high-density regimes. They appear plasmas peaked density profiles weak magnetic shear, which indicates that corresponding instabilities are excited pressure gradients. The time trace fluctuation spectrogram can be either a frequency staircase, different at times or multiple may simultaneously...
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...
Theory and simulation suggest the existence of an E ×B staircase in plasma core consisting a series nested m/n = 0/0 E×B shear layers that regulate turbulent transport across together with mesoscale events occurring between them. Here, we show evidence for these phenomena HL-2A L-mode discharges. Both high resolution electron cyclotron emission Te profiles frequency modulated continuous wave reflectometer ne multiple gradient corrugations. The analysis simultaneous poloidally radially...
Research on beta induced Alfvén eigenmodes (BAEs) driven by energetic ions has been carried out the HL-2A tokamak. The BAEs can be observed in cases of being beyond or below unity. mode frequencies are around 60–95 kHz. radial structures have detected multi-channel microwave reflectometer and soft x-ray arrays. results suggest that highly localized at normalized radius –0.26. Theoretical analyses based general fishbone-like dispersion relation code support experimental measurements both...
Turbulent fluctuations within a quasi-coherent frequency range (peak of ~ 130 kHz, ∆f ≈ tens kHz) are modulated by the rotation low tearing modes in core HL-2A ohmic plasmas. The (QCMs) emerge outside island boundary as O-point passes large cases (w > 4.5 cm), where local electron temperature profile is steepened. Statistical analysis shows that for QCM excitation, threshold value gradient identified and solely observed density discharges, consistent with linear confinement regime. These...
The ELM (edge localized mode) mitigation by SMBI (supersonic molecular beam injection) has been studied in the HL-2A H-mode plasmas. effect and its relationship with deposition position of pedestal are reported for first time experimentally. We found that when is about 20% into pedestal, best achieved, which identified a significant increase frequency also decrease amplitude. theoretical inference no deep injection needed confirmed. sand-pile model used to simulate burst explain different...
The first plasmas have been achieved in the HL-2M tokamak by fulfilling usual criteria for plasma breakdown, i.e. optimal working gas pressure, field null configuration of poloidal magnetic field, reasonable toroidal electrical and clean wall conditions. characterization initiation, such as identification initiation time position, is performed diagnostic data analysis numerical simulation. A model-based method, which enables dedicated pick-up sensors to estimate radial position real time,...