A5089411165- Gyrotron and Vacuum Electronics Research
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Vacuum and Plasma Arcs
- Fusion materials and technologies
- Microwave Engineering and Waveguides
- Pulsed Power Technology Applications
- Metal and Thin Film Mechanics
- Laser-Plasma Interactions and Diagnostics
- Advanced Sensor Technologies Research
- Ionosphere and magnetosphere dynamics
- Electromagnetic Simulation and Numerical Methods
- Antenna Design and Analysis
- Plasma Applications and Diagnostics
- Nuclear Physics and Applications
- Terahertz technology and applications
- Particle Accelerators and Free-Electron Lasers
- Semiconductor materials and devices
- Acoustic Wave Resonator Technologies
- Energy Harvesting in Wireless Networks
- Advanced Antenna and Metasurface Technologies
- Differential Equations and Boundary Problems
- Atomic and Molecular Physics
- Silicon Carbide Semiconductor Technologies
Institute of Applied Physics and Computational Mathematics
2015-2025
Merchants Chongqing Communications Research and Design Institute
2025
State Grid Corporation of China (China)
2024
China University of Petroleum, East China
2024
Southwestern Institute of Physics
2007-2023
Wuhan University of Technology
2023
China Jiliang University
2021
China Academy of Engineering Physics
2013-2019
Southwest Jiaotong University
2016-2019
Hebei Agricultural University
2008
A watt-level traveling wave tube (TWT) amplifier operating above 0.3 THz has been demonstrated. This TWT based on the folded waveguide (FWG) slow-wave structure achieved over 3.1 W of output power at 336.96 GHz, and corresponding device gain achieves 26.2 dB. In this letter, design experimental test results are presented.
Anodic vacuum arc ion sources find wide applications in electric propulsion and thin-film deposition systems, but the poor understanding of generation acceleration mechanisms anode plasma imposes confinement on improving performance these devices. In this paper, discharge process low-current pulsed is self-consistently tracked using a 1D spherical particle-in-cell direct simulation Monte Carlo method coupled with an heat conduction model. The results show that spark stage, electrons emitted...
Abstract Influenced by the external environment and human factors, tunnel portal landslide disaster is very easy to occur in process of crossing mountain. Taking at entrance Qingshashan left line as an example, this paper studies deformation mechanism reinforcement effect means case statistical analysis, numerical simulation field monitoring. It shown that belongs parallel system, below sliding surface. The rock mass disturbed, which results slope body after excavation. Further, structure...
Recent experiment results from the HL-2A tokamak are presented in this paper. Supersonic molecular beam injection (SMBI) with liquid nitrogen temperature propellant is used. Low SMBI can form hydrogen clusters that penetrate into plasma more deeply and efficiently. Particle diffusion coefficient convection velocity (D = 0.5–1.5 m2 s−1 Vconv < 40 m s−1, respectively) obtained at periphery using modulated SMBI. Multi-probe measurements reveal 0–1, n 0 symmetries of directly measured low...
A traveling wave tube amplifier operating above 300 GHz based on folded waveguide (FWG) slow-wave structure is presented in this paper. The design and test results of key components are presented, including FWG structure, electron optic system, RF windows. prototype was fabricated by the high-speed precision milling technology; dimension tolerance achieves ±5 μm, surface roughness 300-nm Ra. This demonstrates over 130 mW maximum output power 19.6 dB small-signal gain at 318.24 from a...
Abstract The supersonic ion jet generated in vacuum arc plasma has numerous applications, but the acceleration mechanism is incompletely understood. In this paper, a one-dimensional spherical discharge model established, and from breakdown to steady stage investigated using particle-in-cell direct simulation Monte Carlo method. results show that potential hump exists locates about <?CDATA $1\,\mu\mathrm{m}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">...
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...
For investigating the mechanism of high power microwave flashover and breakdown on dielectric surface with outgassing, firstly, theoretical modeling is put forward, including dynamic equations, particle-in-cell (PIC) method, secondary emission, Monte-Carlo collision (MCC) method outgassing model. Secondly, based modeling, 1D3V PIC-MCC code programmed by authors. By using this code, weak strong course under different gas moving velocities are studied numerically. The numerical results...
Direct Simulation Monte Carlo and Particle-in-Cell (DSMC-PIC) method is a powerful tool in studying metal vapor vacuum arcs (VA). However, the collision cross sections (Xs) for atoms/ions are not evaluated yet, compared to already developed databases gas discharges. The Xs subject uncertainties which influence accuracy predictive ability of particle models. In this paper, common electrode material copper (Cu) taken as an example survey Xs. Various experimental data, theoretical calculation,...
Abstract Runaway currents following disruptions have an important effect on the first wall in current tokamaks and will be more severe next generation tokamaks. The behavior of runaway massive gas injection (MGI) induced been investigated J-TEXT tokamak. cold front by jet penetrates helically along field lines, preferentially toward high side stops at a location near q = 2 surface before disruption. When reaches it initiates magnetohydrodynamic activities results It is found that MGI He or...
An infrared imaging bolometer diagnostic has been developed recently for the HL-2A tokamak to measure temporal and spatial distribution of plasma radiation. The three-dimensional tomography, reduced a two-dimensional problem by assumption radiation toroidal symmetry, performed. A geometry matrix is calculated with one-dimensional pencil beam approximation. solid angles viewed detector elements are taken into account in defining chord brightness. And local emission obtained inverting measured...
The generation of runaway electrons during disruptions poses a serious threat for the operation ITER. efficiency injection large amounts impurities by massive gas or shattered pellet to achieve suppression might be compromised due low mixture and high Rosenbluth density suppression. transport is dominated magnetic perturbations. perturbations have advantage expelling seeds before they reach energy. Robust has been reached on J-TEXT with mode locking application m/n = 2/1 resonant thermal...
A shattered pellet injector based on in situ technology was installed the HL-2A tokamak, and preliminary experiments were performed recently. In this paper, a fast current shutdown experiment introduces injection (SPI). comparison with spontaneous disruptions massive gas injection, SPI has advantages for disruption mitigation. The experimental results show hard-X-ray radiation intensity (40 to 60 keV) rapidly falling from 20 0 when is used. From this, we can infer that runaway electrons are...
Abstract Studying the characteristics of vacuum arc plasma within a wide range discharge parameters is vital for its applications. In this study, specific discharge, such as cathode temperature ranging from 6000 to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>8000</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mi mathvariant="normal">K</mml:mi> </mml:mrow> </mml:math> , emitted electron spanning 0.69 <mml:mn>2.5</mml:mn> <mml:mi>eV</mml:mi> and...
Abstract A vacuum arc discharge with a metal-deuteride cathode can generate supersonic deuterium ion jet, which finds important applications in sources. In this study, 1D3V spherical particle-in-cell direct simulation Monte Carlo spot model titanium-deuteride is developed to investigate the ionization and acceleration of ions from breakdown steady-arc stage. The effects deuteration concentration on fraction kinetic energy are also analyzed. results show that released atoms start be ionized...
Millimeter wave antennas have the advantage of high directivity, miniaturization, resolution and data transfer speed, wide bandwidth, lower latency. In this work, a millimeter planar array antenna (PAA) with characteristics wideband low sidelobes, which consists eight identical linear (LAA) based on Ti3C2 MXene, is designed fabricated. It first time that MXene are proposed for 5G application. PAA has realized gain 22.22 dBi −10 dB impedance bandwidth measurement covering range from 24 GHz to...
A flexible and compact tri-band antenna based on highly conductive graphene assembled film (GAF) is proposed. The has a small size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$42\times 30.5\times 1.025$ </tex-math></inline-formula> mm3, including three complementary split-ring resonators (CSRR) to realize triple band-notched characteristics. GAF effectively offers operating bands 2.28-2.56 GHz,...
Two m/n = 1/1 kink modes excited by energetic electrons (called double e-fishbone) have been observed near the q 1 flux surfaces in HL-2A discharges. The negative magnetic central shear configuration was achieved with localized electron cyclotron resonance heating and current drive during plasma ramp-up. features of first shown advanced 2D emission imaging (ECEI) system. From ECEI, two propagating opposite directions poloidally clearly observed. These can be found only low density discharge,...
For the first time, edge-localized mode (ELM)-free H-mode was realized in HL-2A tokamak by using electron cyclotron resonance heating and co-current neutral beam injection (NBI) heating. This ELM-free is associated with formation of edge particle transport barrier, an increase density peaking a significant decrease turbulence. During stationary phase, magnetohydrodynamic identified, which has similar characteristics to harmonic oscillation (EHO), as observed other tokamaks. EHO-like enhances...
A semitransparent cathode is proposed for an efficient operation of the relativistic magnetron (RM) with axial extraction. The a kind shaped cathode. It achieved using cylindrical longitudinal strips removed. cross section each removed strip fan-shaped and all emit are connected in central area Results 3-D particle-in-cell simulations show that yields similar performance benefits compared transparent by University New Mexico. Simulation results also output characteristics RM insensitive to...
Abstract As theoretical research further develops, coding metasurfaces have been widely studied and applied due to their uniqueness in digital characterization sequence arrangement. In this work, based on highly conductive graphene‐assembled film (GAF), an ultralight anisotropic broadband metasurface (ABCM) is proposed. The GAF ABCM consists of 16 units with specific phase responses enables complete metal substitution. By arranging the unit cells a order, realizes functions anomalous...
Millimeter-wave and short-range wireless communication is an important part of the Internet Things due to its advantages high transmission speed large data capacity. In this paper, two antenna arrays operating at typical millimeter-wave bands (45 60 GHz) based on graphene-assembled films (GAF) are proposed for application. The 45 GHz film array in form a magnetoelectric dipole with strip slot coupling achieve bidirectional radiation, which offers bandwidth 40–49.5 realized gain 11.8 dBi....