A research for plasma electromagnetic character using JEC-CN-FDTD algorithm based on ICCG method

Song, Da-Jie; Yang, Hong-Wei; Wang, Guangbin

doi:10.1016/j.ijleo.2015.10.139

Cited by 4 publications

(2 citation statements)

References 20 publications

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“…From here, the iterative equation of polarization current density of two‐order precision is expressed as follows [ 21 ] :

J^{n + 1 / 2} = e^{- ν ∆ t} J^{n - 1 / 2} + ∆ {italicte}^{- ν ∆ t / 2} ϵ_{0} ω_{normalp}^{2} E^{n}

…”

Section: Jec‐fdtd Methods and Physical Modelmentioning

confidence: 99%

Transmission characteristics of electromagnetic waves in a semicircular plasma filament layer generated by a femtosecond laser

Pak¹,

Kim

Oh³

et al. 2021

Contributions to Plasma Physics

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The transmission characteristics of electromagnetic (EM) waves in a semicircular plasma filament layer generated by a femtosecond laser were studied in a wide frequency band including radar waves. We have focussed on the influence of plasma parameters and filament arrangement based on the diffraction and superposition theory of EM waves on the transmittance. A numerical simulation model using the current density convolution finite‐difference time‐domain method was constructed in a semicircular multilayer filament structure, and the transmission characteristics of spherical EM waves were examined. The simulation results showed that in this semicircular structure, the transmittance was periodically changed at a frequency interval corresponding to the thickness of the filament channel. This phenomenon was more pronounced as the number of the filament layers increased. In the lower band (<30 GHz), there was little change in the transmittance according to layer‐to‐layer distance, but in the higher band (>30 GHz), it changed irregularly. On the contrary, for the electron number density, it changed regularly in the lower frequency and hardly changed in the higher frequency. When the number of layers was 3 or more, the transmittance became 0 at the centre of the channel, and a discontinuous interference pattern appeared more clearly as the frequency increased.

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“…From here, the iterative equation of polarization current density of two‐order precision is expressed as follows [ 21 ] :

J^{n + 1 / 2} = e^{- ν ∆ t} J^{n - 1 / 2} + ∆ {italicte}^{- ν ∆ t / 2} ϵ_{0} ω_{normalp}^{2} E^{n}

…”

Section: Jec‐fdtd Methods and Physical Modelmentioning

confidence: 99%

Transmission characteristics of electromagnetic waves in a semicircular plasma filament layer generated by a femtosecond laser

Pak¹,

Kim

Oh³

et al. 2021

Contributions to Plasma Physics

View full text Add to dashboard Cite

show abstract

“…As an unconditional stability 3D FDTD algorithm, the CN-FDTD algorithm is based on the CN difference scheme, and each time step can be accomplished in one process. Numerical simulation results prove that the CN-FDTD algorithm can maintain good calculation accuracy when the time step length is significantly longer than that under conditional stability [36][37][38].…”

Section: Numerical Stability Conditionsmentioning

confidence: 99%

Forward Modeling of Water-Rich Regions in Mines Based on Unconditional Stability Finite-Difference Time-Domain

Tian¹,

Ma²,

Zhou³

2019

JESTR

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Water bursting in mines remains one of the major disasters that threatens safe coal production. The traditional detection techniques of water-rich regions in mines can no longer meet new safe production standards and requirements. To solve the constraints on the selection of traditional finite-difference time-domain (FDTD) step length by the Courant-Friedrichs-Lewy stability condition, the unconditional stability Crank-Nicolson FDTD (CN-FDTD) algorithm was introduced into the detection of underground total space, aiming to further increase calculation speed and detection accuracy. The boundary condition of the perfectly matched layer (PML) and numerical stability condition for mine detection were analyzed by studying the basic principle of CN-FDTD. Meanwhile, a detection model of underground water-rich regions was constructed. Influences of excitation function, frequency of excitation source, distance between the anomalous body and the interface, and size of the anomalous body on water-rich region detection were analyzed through Wavenology EM and MATLAB simulation by using the forward algorithm. Results demonstrate that given the same conditions, the Ricker wavelet excitation source has better detection effect than the Blackman-Harris Window (BHW) Function, Gaussian and Delta excitation sources. When the anomalous body is 70 m away from the interface, the excitation source with a central frequency of 15 MHz is the best detection frequency. In addition, forward modeling reveals that when the anomalous body is 50 m away from the interface, the echo signals of a 3 cubic metres anomalous body could still be detected clearly. Theoretically, the existence of an anomalous body can be determined through this echo signal, and its location can be determined through imaging. The study verifies the effective application of CN-FDTD in water-rich region detection in mines. In addition, CN-FDTD solves the constraints of traditional FDTD by stability condition and increases the accuracy of water-rich region detection in mines. This study provides certain theoretical references for the accurate detection of water-rich anomalous bodies in mines.

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Farfield Under Small Scattering Angle in the Rectangular Ag–Si–SiO2 Cavity

et al. 2019

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A research for plasma electromagnetic character using JEC-CN-FDTD algorithm based on ICCG method

Cited by 4 publications

References 20 publications

Transmission characteristics of electromagnetic waves in a semicircular plasma filament layer generated by a femtosecond laser

Transmission characteristics of electromagnetic waves in a semicircular plasma filament layer generated by a femtosecond laser

Forward Modeling of Water-Rich Regions in Mines Based on Unconditional Stability Finite-Difference Time-Domain

Farfield Under Small Scattering Angle in the Rectangular Ag–Si–SiO2 Cavity

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