A5062537933- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Photonic and Optical Devices
- Terahertz technology and applications
- Photoacoustic and Ultrasonic Imaging
- Physics of Superconductivity and Magnetism
- Plasmonic and Surface Plasmon Research
- Ultrasound and Hyperthermia Applications
- Ultrasound and Cavitation Phenomena
- Advanced Differential Geometry Research
- Aquatic and Environmental Studies
- Neutrino Physics Research
- Dust and Plasma Wave Phenomena
- Advanced Fiber Laser Technologies
- Laser-induced spectroscopy and plasma
- Orbital Angular Momentum in Optics
- Mobile Agent-Based Network Management
- Material Science and Thermodynamics
- Topological Materials and Phenomena
- Gyrotron and Vacuum Electronics Research
Chinese Academy of Sciences
2012-2024
Aerospace Information Research Institute
2024
Cisco College
2024
University of Science and Technology of China
2001-2023
Institute of Plasma Physics
2012-2023
Shenzhen University
2020-2023
Hefei Institutes of Physical Science
2023
Anhui Institute of Optics and Fine Mechanics
2022
Hefei University of Technology
2014-2017
University of Missouri
1989
A 4.6 GHz lower-hybrid current drive (LHCD) system has been firstly commissioned in EAST the 2014 campaign. The first LHCD results with show that LHW can be coupled to plasma a low reflection coefficient, and rotation, modify profile, heat effectively. By means of configuration optimization local gas puffing near antenna, good LHW–plasma coupling coefficient less than 5% is obtained. maximum power up 3.5 MW. (CD) efficiency 1.1 × 1019 m−2 W−1 central electron temperature above 4 keV,...
Aimed at high-confinement (H-mode) plasmas in the Experimental Advanced Superconducting Tokamak (EAST), effect of local gas puffing from electron and ion sides a lower hybrid wave (LHW) antenna on LHW–plasma coupling high-density experiments with current drive (LHCD) are investigated EAST. results show that side is more favourable to improve compared side. Investigations indicate without affected by density near LHW grill (grill density), hence leading multi-transition low–high–low (L–H–L)...
EAST has been equipped with two high power lower hybrid current drive (LHCD) systems operating frequencies of 2.45 GHz and 4.6 GHz. Comparative LHCD experiments the different were performed in same conditions plasma for first time. It was found that (CD) efficiency heating effect are much better LH waves than one High confinement mode (H-mode) discharges as sole auxiliary source have obtained is higher respect to produced previously by A combination ray-tracing Fokker-Planck calculations...
Terahertz scanning tunneling microscopy (THz-STM) has emerged as a potent technique for probing ultrafast nanoscale dynamics with exceptional spatiotemporal precision, whereby the acquisition of THz near-field waveforms holds paramount significance. While substantial efforts have been dedicated to retrieving waveform utilizing photoemission current or molecular sensor, these methods are challenged by intense thermal effects complex sample preparations. In this study, we introduce universal...
Abstract Two important issues in achieving lower hybrid current drive (LHCD) high confinement plasma EAST are to improve wave (LHW)-plasma coupling and the at a density. Studies different configurations with directions of toroidal magnetic field ( B t ) show that density near antenna is affected by both radial electric induced without LHW E r_plasma scrape off layer (SOL), power r_LH grill. Investigations indicate r × SOL leads effect configuration on LHW-plasma accounts for asymmetric...
Significant progress on both L- and H-mode long-pulse discharges has been made recently in Experimental Advanced Superconducting Tokamak (EAST) with lower hybrid current drive (LHCD) [J. Li et al., Nature Phys. 9, 817 (2013) And B. N. Wan Nucl. Fusion 53, 104006 (2013).]. In this paper, LHCD experiments at high density L-mode plasmas have investigated order to explore possible methods of improving (CD) efficiency, thus extend the operational space performance plasma regime. It is observed...
More economical fusion reactors might be enabled through the cyclic operation of lower hybrid current drive. The first stage would to ramp up plasma with waves alone in low-density plasma. Such a ramp-up was carried out successfully on EAST tokamak. ramped time-averaged rate 18 kA/s (LH) power. average conversion efficiency Pel/PLH about 3%. Over transient phase, faster obtained. These experiments feature separate measurement L/R time at up.
Effect of gas puffing from electron-side and ion-side on lower hybrid wave (LHW)-plasma is investigated in experimental advanced superconductive tokamak for the first time. Experimental results with different flow rates show that electron density at grill higher case electron-side; consequently, a reflection coefficient observed, suggesting better effect LHW-plasma. The difference edge between electron- cases suggests local ionization puffed plays dominant role affecting due to movement...
The results presented in this paper are an extension of our recent (Kong et al 2012 Plasma Phys. Control. Fusion 54 105003) studies on lower hybrid wave (LHW) coupling. By optimizing the shape LH grill, misalignment between poloidal limiter (PL) and grill is nearly eliminated coupling LHW improved, especially top row, although some discrepancies still present case with low edge density. Density modifications both by ion cyclotron range frequency (ICRF) power studied EAST. Experimental show...
A triple Langmuir probe is mounted on the top of Lower Hybrid (LH) antenna to measure electron density near LH grills in Experimental Advanced Superconducting Tokamak. In this work, power ranges from 2.3 MWm−2 10.3 and rate puffing gas varies 1.7 × 1020 el/s 14 el/s. The relation between edge (from 0.3 ne_cutoff 20 ne_cutoff, where cutoff density, = 0.74 1017 m−3 for 2.45 GHz lower hybrid current drive) grill reflection coefficients investigated. factors, including gap last closed magnetic...
High-confinement (H-mode) discharges with lower hybrid current drive (LHCD) as the only heating source are obtained on EAST. In this paper, an empirical transport model of mixed Bohm/gyro-Bohm for electron and ion heat was first calibrated against a database 3 L-mode shots The temperature profiles well reproduced in predictive modeling coupled to suite codes CRONOS. CRONOS calculations experimental also performed power balance analysis. addition, time evolutions LHCD calculated by C3PO/LUKE...
Couplings of lower hybrid wave (LHW) with different divertor configurations are studied in EAST. With an anti-clockwise toroidal magnetic field and similar plasma parameters, experimental results show that the best coupling occurs single null (LSN) configuration, whereas worst double-null plasma. Furthermore, for case clockwise field, LHW becomes better upper configuration worse LSN Such phenomena is possibly related to flux induced by Er × Bt edge recycling intensity represented Da, where...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation L. Zhang, T. B. J. Ding, M. H. Li, F. K. Liu, Shan, W. Wei, Y. C. Yang, Z. G. Wu, Wang, Zhao, D. Ma, Xiu, X. Jia, Cheng, Xu, Tang, Zhu, EAST Team; Preliminary investigation of the effects lower hybrid power on asymmetric behaviors in scrape-off layer experimental advanced superconducting tokamak. Physics...
We studied the effects of ionization in a sonoluminescing (SL) bubble within hydrodynamic framework. The thermodynamic variables and degrees inside throughout an oscillation cycle are obtained by solving equations assuming spherical symmetry. Several models used to compute emitted radiation, which then compared with experimental data. Numerical results show that shock waves absent stable SL regime, compressional already strong enough produce moderate temperature ionization. at center found...
Repeatable H-mode plasma in EAST is obtained with a local gas puffing near lower hybrid wave (LHW) antenna. The density modification front of LHW grill during mainly depends on the competition between ponderomotive force and ionization neutral gas. Effects edge localized mode (ELM) coupling are analyzed. Studies suggest that recycling plays an important role determining coupling. burst ELM enhances at mouth, hence improving low recycling, whereas such effect could decrease high recycling. In...
We demonstrate a compact in-fiber integrated microresonator based on silica microsphere and microstructure fiber. Whispering-gallery-modes (WGMs) are effectively excited through evanescent field coupling between the one of input tube waveguides negative curvature The WGM spectrum with Q-factor ∼2.56 × 103 extinction ratio ∼15.2 dB is achieved. transmission spectra evolution for 5 h reveals long-term stability excitation. experimental results indicate that resonator has advantages high...
Stable and unstable manifolds, originating from hyperbolic cycles, fundamentally characterize the behaviour of dynamical systems in chaotic regions. This letter demonstrates that their shifts under perturbation, crucial for chaos control, are computable with minimal effort using functional derivatives by considering entire system as an argument. The homoclinic heteroclinic orbits, intersections these readily calculated analyzing movements intersection points.
This study extends the functional perturbation theory, originally developed for orbits and periodic in dynamical systems, \textit{e.g.} a map $\mathcal{P}$, to derive formulae deformation of an $d$-dimensional invariant torus, on which one can define $\mathcal{P}^k$ $k\in \mathbb{R}$ even $\mathbf{k}\in\mathbb{R}^d$ continuize generalize exponential function $\mathcal{P}^{\mathbf{k}}$ $k$. The tori, manifest as closed flux surfaces magnetic confinement fusion (MCF) machines, are dominant...
Periodic orbits and cycles resp. play a significant role in discrete- continuous-time dynamical systems (i.e. maps flows). To succinctly describe their shifts when the system is applied perturbation, notions of functional derivative are borrowed from analysis to consider whole as an argument geometric representation periodic orbit or cycle. The orbit/trajectory orbit/cycle analyzed concluded formulae for maps/flows, respectively. theory shall be beneficial sensitivity perturbation analysis,...
The development of near-field THz microscopes has transcended the diffraction limitation traditionally constraining super-resolution imaging, heralding a new era precision. Notably, Terahertz combined scanning tunneling microscopy (THz-STM) distinguished itself by achieving unparalleled spatial resolution alongside remarkable temporal Despite significant advancements in THz-STM imaging research, thorough exploration its unique features remains elusive, particularly resolving local electronic...
Abstract The edge turbulence characteristics and the induced radial transport have been investigated in localized mode (ELM) suppression by using <?CDATA $n = $?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>n</mml:mi> <mml:mo>=</mml:mo> </mml:math> 4 resonant magnetic perturbation coils on EAST, with ${q_{95}} <mml:mrow> <mml:msub> <mml:mi>q</mml:mi> <mml:mn>95</mml:mn> </mml:mrow> </mml:msub> 3.6 electron collisionality $\nu _{\text{e}}^* \approx...
We have proposed and implemented a scheme for Spiral Phase Plate (SPP) with continuous surface fabrication on fiber tips. By combining Focused Ion Beam-Scanning Electron Microscope (FIB-SEM) system bitmap (BMP) format processing method, we fabricated SPP the topological charge of 1 tip, experimentally analyzed diffraction interference properties generated vortex beam. The experimental results were in good agreement simulation results, which indicated by this method had optical high...