A study of the transmission characteristics of terahertz waves in hypersonic target flow field

Zhang, Jie; Han, Bing; Zhao, Shan‐Chao; Zhang, Guodong; Duan, Wen‐Shan

doi:10.1017/s0022377822000678

Cited by 4 publications

(2 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the algorithm, the scattering matrix method, which is capable of analyzing non-uniform plasma, is chosen to calculate the transmission characteristics of terahertz waves in plasma. Dong et al [10] investigated the transmission characteristics of terahertz waves in plasma sheaths with different flight speeds and different incidence angles by using the finite difference method of the time domain (FDTD). Chen et al [11] investigated the transmission characteristics of electromagnetic waves in plasma sheaths at different angles of incidence by using the improved scattering matrix method (ISMM).…”

Section: Introductionmentioning

confidence: 99%

“…Chen used USim to simulate the flow field of the RAM-II generated under different reentry cases in the flow field in the plasma sheath [14]. Zhang et al [15] investigated the transmission properties of terahertz waves in a two-dimensional(2D) hypersonic target flow field and found that the transmission properties of terahertz waves in plasma are mainly affected by the electron density. Studies using USim software for three-dimensional(3D) flow field simulations are rarely reported.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Terahertz wave propagation characteristics in SMM-based three-dimensional plasma fluid

Zhang,

Wang,

et al. 2024

Phys. Scr.

View full text Add to dashboard Cite

During the return to the atmosphere of a hypersonic vehicle in adjacent space, a plasma sheath forms on the surface of the vehicle, which blocks normal electromagnetic communications. The "blackout" phenomenon caused by plasma sheaths has received much attention. This paper focuses on the American RAM-C vehicle as the research object, and utilizes the fluid simulation software USim to numerically simulate the pressure, temperature, and electron density under different flight conditions, and based on the simulation results, selects the appropriate electron density and plasma collision frequency, introduces the terahertz (THz) wave, and adopts the scattering matrix method (SMM) to study the propagation characteristics of the vertically incident non-uniform magnetized plasma with the terahertz wave. Among other things, the transmission characteristics of terahertz waves in the plasma are affected by the flight altitude and flight angle of attack of the vehicle. The conclusions indicate that the transmissivity of terahertz wave transmission in plasma increases, and the reflectivity and absorptance decrease with increasing flight altitude and flight angle of attack. Under the condition of controlling other flight parameters unchanged, the plasma frequency and collision frequency decrease with the increase of flight altitude. The larger the flight angle of attack is, the larger the plasma frequency and collision frequency are. The electron density on the wall surface of the vehicle was also tested, and it was found that the lowest electron density was found at the tail end of the leeward surface. This study can provide some theoretical references for mitigating the "blackout" phenomenon of re-entry vehicles.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Terahertz wave propagation characteristics in SMM-based three-dimensional plasma fluid

Zhang,

Wang,

et al. 2024

Phys. Scr.

View full text Add to dashboard Cite

show abstract

Study on the generation of terahertz waves in collision plasma

Bao,

He,

et al. 2024

Physics of Plasmas

View full text Add to dashboard Cite

Terahertz communication technology holds promise for solving the challenging “blackout” problem. Research has revealed that the spectrum exhibits new peaks when terahertz waves propagate through plasma. In the realm of communications, elucidating the underlying physical mechanisms responsible for these novel peaks is of paramount importance. In this paper, a combination of theoretical analysis and simulation is utilized to investigate the causes of these spectral changes. Theoretically, the expression for the relative dielectric constant of plasma has been refined by incorporating collision terms. Drawing on radiation theory, a particle whose motion is interrupted by collisions can be considered equivalent to a damped harmonic oscillator. Thus, the frequency expression of the new peak was derived. Furthermore, the simulation involved the interaction of a terahertz wave, which had a frequency of 1 THz and lasted for 2 ps, and plasma characterized by a central electron density of 1021 m−3 and a collision frequency of 0.114 THz. The simulation results are consistent with the frequency expression of the new peak. In sum, this study found that collisions between electrons and neutral particles within plasma cause a shift in the frequency of terahertz waves, and has derived the frequency expression. This plasma model can be used to estimate the frequency range of terahertz waves that are generated as they propagate through collisional plasmas.

show abstract

Theoretical Study on the Impacts of Time-Varying Reentry Vehicles Plasma Sheath on the Terahertz Array Antenna Performance

Ni,

Zhao,

Yuan

et al. 2023

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

A study of the transmission characteristics of terahertz waves in hypersonic target flow field

Cited by 4 publications

References 21 publications

Terahertz wave propagation characteristics in SMM-based three-dimensional plasma fluid

Terahertz wave propagation characteristics in SMM-based three-dimensional plasma fluid

Study on the generation of terahertz waves in collision plasma

Theoretical Study on the Impacts of Time-Varying Reentry Vehicles Plasma Sheath on the Terahertz Array Antenna Performance

Contact Info

Product

Resources

About