A5111766111- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Physics of Superconductivity and Magnetism
- Educational Reforms and Innovations
- Remote-Sensing Image Classification
- Advancements in PLL and VCO Technologies
- Particle Dynamics in Fluid Flows
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Geologic Mapping
- Dust and Plasma Wave Phenomena
- Combustion and flame dynamics
- Advanced Combustion Engine Technologies
- Plasma Diagnostics and Applications
- Ideological and Political Education
- Iterative Learning Control Systems
Chinese Academy of Sciences
2013-2023
Hefei Institutes of Physical Science
2023
Institute of Plasma Physics
2013-2021
Abstract The planar laser induced fluorescence (PLIF)/Mie scattering technique has been established as an effective method for measuring the Sauter Mean Diameter (SMD) distribution in dense fuel sprays. This typically utilized a 266 nm laser. However, strong absorption of wavelengths ranging from to 274 sprays affected detection Mie signals. Therefore, it was proposed use excitation and 532 radiation In this study, look-up table (LUT) created by correlating PLIF/Mie ratio with using Phase...
A stationary edge-localized mode (ELM)-absent H-mode regime, with an electrostatic edge coherent (ECM) which resides in the pedestal region, has been achieved EAST tokamak recently. This regime allows operation of a nearly fully noninductive long pulse (>15 s), exhibiting relatively high and good global energy confinement near 1.2, excellent impurity control. Furthermore, this is mostly obtained 4.6 GHz lower hybrid current drive (LHCD) or counter-current neutral beam injection (NBI), plus...
A quasi-coherent mode (QCM) was measured by the tangential CO2 laser collective scattering diagnostic at high plasma electron density during both enhanced Dα/small edge-localized (ELM) and ELM-free H phases in Experimental Advanced Superconducting Tokamak (EAST). results from only local oscillator prove that QCM is far-forward mode. The driven fluctuation (k⊥<3 cm−1) magnetic suggest an electromagnetic typical frequency of f ≈ 26.5 kHz. combination analysis signals Mirnov suggests has...
In this paper, we present clear experimental evidence of core region nonlinear coupling between (intermediate, small)-scale microturbulence and an magnetohydrodynamics (MHD) mode during the current ramp-down phase in a set L-mode plasma discharges advanced superconducting tokamak (EAST, Wan et al (2006 Plasma Sci. Technol. 8 253)). Density fluctuations broadband () MHD (toroidal number , poloidal ) are measured simultaneously, using four-channel tangential laser collective scattering...
A highly reproducible spontaneous non-inductive low recycling no-ELM regime has been achieved in the EAST superconducting tokamak with water-cooled tungsten divertor and molybdenum first wall. The salient feature is that after L-H transition, emission intensity, neutral pressure separatrix electron density all decrease, amplitude of ELMs decreases simultaneously until they disappear completely. This scenario exhibits a distinct threshold, which dependent on plasma current wall condition....
High-confinement (H-mode) plasma was achieved by injecting frozen deuterium pellets in the experimental advanced superconducting tokamak (EAST). Interesting phenomena of simple and two-stage low–high confinement (L–H) transitions are observed EAST with radio frequency heating after pellet injection. The results L–H induced discussed detail different theories. It is found that injection can reduce power threshold H-mode. Furthermore, pellet-induced edge density gradient an important parameter...
The core microturbulence (, ) provided by a tangential CO2 laser collective scattering system on the EAST tokamak, in low (L) and high (H) confinement mode regimes respectively, are presented. We report change of characteristics from L-mode to H-mode: firstly, spectrograms show redistribution frequency domain after L–H transition; secondly, time evolution integrated spectral power displays that amplitude H-mode is much larger than L-mode; thirdly, cross-correlation time-frequency spectrum...
Since Alfvén activity and turbulence are ubiquitous in magnetically confined plasma, it is important to understand the possible roles have nonlinear evolution of turbulence. The designed experiments low collisionality dedicated studying dynamics between toroidal eigenmodes (TAEs), assessing multi-scale physics on long-term scale behavior fusion plasma. In TAEs (f ∼ 200 kHz, n = 1) mitigation under resonant magnetic perturbations (RMP, nupper 2 nlower 3), there a (∼500 ms) quasi-stationary...
In this paper, we present experimental studies of both high-kr (k⊥ = 10,18,26 cm-1, and k⊥ρs 2,3.6,5.2, respectively; kr ≈ 0.87 k⊥) high-kθ 8,20 ≤ 0.73,1.86, kθ turbulence behavior during a ohmic energy confinement degradation phase in Experimental Advanced Superconducting Tokamak (EAST). High-kr from density fluctuation at r/a 0.5 high- 0.7-0.97 were measured by tangential poloidal CO2 laser collective scattering diagnostics, respectively. Note that kr, kθ, k⊥ ρs are radial wavenumber,...
The formation of radial electric field Er in the tokamak edge region is calculated based on collisionless ion orbit loss. loss generates a negative Er, which turn affects As result, can saturate at either low or high value, depending plasma parameters. When temperature higher than threshold, self-sustaining growth both and found, leading to saturation value milliseconds. This mechanism provides possible explanation for strong during transition from (L) (H) confinement regime observed plasmas.
Both k1 = 12 cm−1 (intermediate-k) and k2 22 (high-k) micro-turbulence (k⊥ρs ∼ 1–4) in gradient region plasmas were measured simultaneously by the EAST poloidal CO2 laser collective scattering system. Their behaviors have been studied detail both ELM-free/type III ELMy enhanced Da (EDA) H mode plasma discharges. Compared with that previous L phase, it can be seen obviously mean frequency of lower-k (k1) increases higher-k (k2) decreases during ELM-free or type while frequency-integrated...
Double null magnetic configurations with different elongation κ and triangularity δ are constructed by using an analytical solution of the Grad–Shafranov equation. The ion orbit losses in plasma edge region calculated solving guiding center equation for values δ. It is found that loss larger a smaller value or variation fraction on surface also studied.
Two different confinement transition discharges, the low-intermediate-high (L-I-H) and low-intermediate-low (L-I-L) transitions, respectively, have been obtained by lower hybrid current drive with lithium wall conditioning in EAST superconducting tokamak. The dynamic features of short-scale turbulent fluctuations two discharges are investigated a tangential CO2 laser collective scattering system. It is found that great changes broadband amplitude structure characteristics closely related to...
Abstract Avoiding the plasma instability, especially disruption is an important problem for stable operation of tokamak. Large-scale instabilities driven by free energy evolve nonlinearly and lead to disruption. The microscale turbulence highly sensitive change energy. paper show electron-scale evolution in pre-precursor phase TMs included with <?CDATA ${{\rm{CO}}}_{2}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi...
Abstract Micro-instabilities are often invoked to account for the anomalous transport of energy and particles in fusion plasmas, whose origin contributions remain uncertain. The dynamic features microturbulence plasma core gradient region investigated simultaneously by a poloidal CO 2 laser coherent scattering diagnostic system on experimental advanced superconducting tokamak (EAST). In 2018, an improved confinement mode characterized peaked density profile is observed current ramp-down...
Beta-induced Alfven eigenmodes (BAEs) during strong tearing modes (TMs) have been frequently observed in fast-electron plasmas of EAST tokamak. The dynamics the short-scale ( density fluctuations activity BAEs with TMs has preliminarily investigated by a tangential CO2 laser collective scattering system. results suggest active, but different, response to and BAEs. In low-frequency (0–10 kHz) part fluctuations, there are harmonic oscillations totally corresponding those TMs. medium-high...
The interchange-like transport is observed between two resonant surfaces (q = 1 and q 4/3, where the safety factor) in a finite small positive magnetic shear regime with mild core oscillations experimental advanced superconducting tokamak strong on-axis electron heating H-mode plasmas. It synchronized increasing gradient of soft X-ray profile intensifying density fluctuations core. analysis two-fluid simulations combined measurements indicates destabilization collective resistive interchange...