Zhiwei Dong

Guilin University of Electronic Technology

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Ye Dong

Institute of Applied Physics and Computational Mathematics

Yuanqin Xia

Hebei University of Technology

Qianhong Zhou

Institute of Applied Physics and Computational Mathematics

Jianhong Hao

North China Electric Power University

Deying Chen

Harbin Institute of Technology

Shixiong Qian

Fudan University

Wenyuan Yang

Institute of Applied Physics and Computational Mathematics

Bi-Xi Xue

Institute of Applied Physics and Computational Mathematics

Haijing Zhou

Institute of Applied Physics and Computational Mathematics

Sheng Zhang

Tianjin University

Cooperative Institutions

Chinese Academy of Sciences

117

Harbin Institute of Technology

University of Chinese Academy of Sciences

Peking University

Fudan University

Sun Yat-sen University

Shanghai Jiao Tong University

Central South University

Institute of Applied Physics and Computational Mathematics

Zhejiang University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Femtosecond Third-Order Optical Nonlinearity of Au:Bi ₂ O ₃ Nanocomposite Films

Chinese Physics Letters (2007)

You Guan-Jun Peng Zhou Zhiwei Dong Zhang Chun-feng Chen Liang-Yao

Ultrafast third-order optical nonlinearities of the as-deposited and annealed Au:Bi2O3 nanocomposite films deposited by magnetron cosputtering are investigated by using femtosecond time-resolved optical Kerr effect (OKE) and pump–probe techniques. The third-order optical nonlinear susceptibility is estimated to be 2.6×10−10 esu and 1.8×10−9 esu at wavelength of 800 nm, for the as-deposited and the annealed film, respectively. The OKE signal of the as-deposited film is nearly temporally symmetrical with a peak centred at zero delay time, which indicates the dominant contribution from intraband transition of conduction electrons. For the annealed film, the existence of a decay process in OKE signal implies the important contribution of hot electrons. These characteristics are in agreement with the hot electron dynamics observed in pump–probe measurement.

10.1088/0256-307x/24/3/039

Cite

Citations (3)

Comparison of photon energies and field techniques for ovarian dose reduction in volumetric modulated arc therapy

Radiation Physics and Chemistry (2024)

Xiao-Gang An Yuzhu Zhang Zhiwei Dong Ruo-Hui Zhang

10.1016/j.radphyschem.2024.111567

Cite

Citations (0)

Physical research on ionization of high power microwave propagating in atmosphere

High Power Laser and Particle Beams (2006)

Chen Yashen Zhiwei Dong Qiang Zhao Huifang Sun

That the disconsistency between the plane one-dimension assumption and the law that the microwave energy flux per unit area is inversely proportional to the square of the propagation distance is pointed out. The fundamental equations of the HPM propagation in the atmosphere under the beam flux one-dimension assumption are given. The characteristics and scaling laws of the ionization atmosphere are studied in detail. When n/nc is not too small, the great difference on the tail-erosion between the plane one-dimension and the beam one-dimension assumptions is presented.

Source

Cite

Citations (0)

Influence of Geomagnetic Field on the Long-Range Propagation of Relativistic Electron Beam in the Atmosphere

IEEE Transactions on Plasma Science (2020)

Bi-Xi Xue Jianhong Hao Qiang Zhao Zhiwei Dong

It is known that Earth's atmosphere and geomagnetic field affect the propagation of an artificial electron beam; many previous studies have neglected the effect of their variation on the propagation dynamics. In this article, parameters in envelope equations were modified according to the International Geomagnetic Reference Field (IGRF) model and MSIS-90 atmosphere model; then, the model was constructed to study the propagation of artificial electron beam in the atmosphere. Calculation of the beam's energy loss and radial expansion in propagation showed that the variation of geomagnetic field intensity can be the main reason for the radial pinch in the altitudes above 150 km, and the ambient particle density plays a dominant role in the beam's radial expansion in altitudes below 150 km. The Monte Carlo model was used to simulate the interactions of a relativistic (1 MeV) electron beam with the atmosphere in the altitude range 100-150 km. Energy deposition density demonstrates that the geomagnetic field can limit the radial expansion of the beam. The relativistic electron beam was emitted horizontally in the atmosphere. The geomagnetic field can limit the beam's radial expansion and cause the beam to propagate along the field line, irrespective of the direction in which the beam is emitted.

Relativistic electron beam

10.1109/tps.2020.3026088

Cite

Citations (8)

A Compact C-Band Magnetically Insulated Line Oscillator

Guo Yan-hua Zhikai Fan Zhiwei Dong Haijing Zhou He Hu

The magnetically insulated line oscillator (MILO) is a high power microwave (HPM) pulsed device, potentially of gigawatt power, that combines the technologies of magnetically insulated electron flow with a slow wave structure (SWS). This combination makes the tube a device capable of operating over a wide voltage range. Our concern is to design a compact experimental setup. Using the theoretical and experimental results as guides, a novel RF choke and a beam dump disk have been introduced into the MILO. In experiments, high power microwave of the TM ₀₁ mode is generated from the device with a frequency range of 3.70-3.72 GHz and a power level of above 500 MW, when the diode voltage is 400-430 kV and the beam current is 30-33 kA. The experimental results are in agreement with the computation values

Choke

W band

Line (geometry)

10.1109/ceem.2006.257945

Cite

Citations (0)

Vibrational–translational relaxation in nitrogen discharge plasmas: Master equation modeling and Landau–Teller model revisited

AIP Advances (2020)

Wei Yang Qianhong Zhou Qiang Sun Zhiwei Dong Eryan Yan

Vibrational–translational (V–T) relaxation is quite common in molecular nitrogen discharge non-equilibrium plasmas. In this paper, the energy relaxation in V–T transition is investigated by master equation modeling on all vibrational levels below the dissociation limit. The state-to-state transition rates are calculated by a forced harmonic oscillator (HO)-free rotating model. Meanwhile, the classic Landau–Teller model based on the HO of vibrational levels is revisited. First, the V–T relaxation in a heat bath is compared between the HO model, Morse’s anharmonic oscillator (AHO) model, and realistic vibrational levels by a direct-potential-fit analysis of spectroscopic data. The relaxation of average vibrational energy using the AHO model is faster than that using the HO model. Then, the influence of more frequent vibrational–vibrational (V–V) collision on the V–T transition in the heat bath is investigated by using different numbers of vibrational levels. The anharmonic effect is significant with more vibrational levels. Finally, the V–T energy transfer is modeled by a coupled solution to master equations and gas heating. The stronger the non-equilibrium between vibrational and translational temperature in the beginning, the larger the difference that can be obtained between the HO model (Landau–Teller theory) and realistic vibrational levels.

Vibrational energy relaxation

Vibrational partition function

Morse potential

10.1063/5.0021993

Cite

Citations (8)

Linear analysis and oscillation study on folded waveguide traveling wave tube for subterahertz radiation

Wenyuan Yang Zhiwei Dong Ye Dong Haijing Zhou

The perturbed dispersion relation in folded waveguide TWT is derived and solved using MATLAB. Calculation results show that beam voltage affects the linear growth rate significantly. And the width of the cross section, as a "free" parameter, affects the start oscillation conditions obviously.

Oscillation (cell signaling)

Traveling-wave tube

Waveguide

10.1109/icimw.2010.5612979

Cite

Citations (1)

Ultrafast nonlinear optical properties of dye-doped PMMA discs irradiated by 40fs laser pulses

Optics & Laser Technology (2009)

Yuanqin Xia Yugang Jiang Rongwei Fan Zhiwei Dong Weijiang Zhao

Rhodamine 6G

Rhodamine

Two-Photon Absorption

Rhodamine B

10.1016/j.optlastec.2009.01.011

Cite

Citations (19)

Particle-In-Cell Simulation on the Multipacting Process of a Novel High-Current Density Cathode

IEEE Transactions on Plasma Science (2019)

Ye Dong Qingxiang Liu Xiangqiang Li Haijing Zhou Zhiwei Dong

The configuration design of a novel high-current density cathode for producing a ring-like electron beam is briefly introduced. Due to the complicated physical process of this novel cathode, in this paper, only the temporal evolution of multipacting on this cathode surface is numerically simulated by using the particle-in-cell method. The simulation results indicate that the multipacting process could be successfully achieved on the surface of this cathode. In multipacting process, both the electron number and output current start rapid exponential increases in very short time and then tend to be saturation with slow decreases. The multipacting start point is not at the triple-junction (vacuum-metal-dielectric) region but has a distance to the region. The saturation region of multipacting will expand toward the outlet with the spreading speed on the order of 10 ⁷ m/s, which agrees with the speed of the luminous front of the initial surface flashover measured by experiment, and the emission current density of the cathode could reach the level of kA/cm ² . The region of multipacting electrons will first be lengthened and then will be shortened due to the region of deposited positive charges expanding to the outlet and the maximum value of deposited positive charges moving from the triple-junction region to the outlet side.

Saturation (graph theory)

Saturation current

Secondary emission

10.1109/tps.2018.2888554

Cite

Citations (5)

A Novel Coaxial Relativistic Backward-Wave Oscillator for Millimeter Wave Generation

IEEE Transactions on Plasma Science (2012)

Wenyuan Yang Zhiwei Dong Ye Dong Haijing Zhou

A novel coaxial relativistic backward-wave oscillator (C-RBWO) for millimeter wave generation is proposed and studied by simulation. In the proposed C-RBWO, a coaxial structure is used in the beam-wave interaction region. According to the dispersion relations in the slow-wave structure region, a new simple and effective reflector is designed for effective cutoff the backward-wave at the electron-injector end. Nonuniform corrugation depth is used to increase the efficiency. For an electron beam with 263-kV voltage and 610-MW power, about 80-MW output power is obtained by simulation at 96.2 GHz. The C-RBWO operates at a low magnetic field (3.7 T) below the cyclotron resonance value (about 10.2 T). The output efficiency is beyond 13%.

Backward-wave oscillator

Extremely high frequency

Coaxial

Relativistic electron beam

Reflector (photography)

10.1109/tps.2012.2188047

Cite

Citations (8)