共查询到20条相似文献,搜索用时 93 毫秒
1.
J. Wu 《International Journal of Electronics》2013,100(11):661-672
In this paper, a new type of plasma-filled coaxial cylindrical dielectric slow-wave structure that is very beneficial to the beam-wave interaction of the high-power microwave source is developed. The Cherenkov radiation in the plasma-filled coaxial cylindrical dielectric slow-wave structure is examined by use of the self-consistent linear field theory. The dispersion equation and the synchronized condition as well as the wave growth rate of the beam-wave interaction are derived. The dispersion equation clearly shows that the Cherenkov radiation excited in the plasma-filled coaxial cylindrical dielectric slow-wave structure results from the coupling between the slow electromagnetic wave, TM-modes, propagated along the slow-wave structure and the negative-energy space-charge wave propagated along the relativistic electron beam. The numerical results indicate that the dispersion curves are divided into two branches due to the presence of the background plasma in the coaxial cylindrical dielectric slow-wave structure for the identical electromagnetic wave mode, and the radial distributions of the longitudinal fluctuating electric field corresponding to the two dispersion curve branches are completely different. Injection of the background plasma into the slow-wave structure can enhance the output frequency and the wave growth rate of the beam-wave interaction and enables the high-power microwave source that utilizes this kind of slow-wave structure to gain more output power of the microwave with higher output frequency. 相似文献
2.
Jianqiang Wu Shenggang Liu Yuanlong Mo 《Journal of Infrared, Millimeter and Terahertz Waves》1995,16(12):2181-2194
On the basis of the reference [1], excitation of Cherenkov radiation with arbitrary azimuthal mode number by a thin annular relativistic electron beam in a plasma-filled dielectric-lined slow-wave waveguide is studied in this paper. A determinantal dispersion equation is obtained. This general dispersion equation is valid for arbitrary azimuthal mode number, and the growth rate of the wave is derived from it. Finally, the effects of the background plasma density on the dispersion relation, the background plasma density and the electron beam radius on the growth rate of the wave are presented. Formulas and results offerd in this paper are general, and are of particular value of reference to the beam-wave interaction in azimuthally unsymmetrical slow-wave waveguide. 相似文献
3.
Jianqiang Wu Caidong Xiong Shenggang Liu 《Journal of Infrared, Millimeter and Terahertz Waves》1995,16(9):1573-1581
An axial relativistic electron beam passing through a slow wave structure is unstable to an electromagnetic perturbation whose phase velocity equals the velocity of the beam. This phenomenon of Cherenkov emission is the basis of all traveling wave tubes. In this paper an excitation of Cherenkov radiation by a thin annular relativistic electron beam in a plasma-filled dielectric-lined waveguide is analysed by use of the self-consistent linear theory. The effect of the thin annular electron beam on the beam-wave interaction is completely described by a jump condition. The dispersion equation and the simultaneous condition of the beam-wave interaction are derived. Finally, the growth rate of the wave is obtained, and the effect of the background plasma density and the electron beam radius on the growth rate of the wave are presented. 相似文献
4.
Jianqiang Wu Caidong Xiong Shenggang Liu 《Journal of Infrared, Millimeter and Terahertz Waves》1995,16(8):1317-1328
The effect of three-dimensional perturbed velocity and three-dimensional perturbed current density on the beam-wave interaction of dielectric Cherenkov maser is analysed by use of the self-consistent linear field theory. Three distinct cases are considered. First, the propagation of the electron beam in an annular dielectric liner enclosed by a loss-free conducting wall is investigated. The dispersion equation and the simultaneous condition of the beam-wave interaction are derived. It's clearly shown that the instability of the interaction results from the coupling of the TM mode in the dielectric lined slow-wave waveguide to the beam mode via the electron beam. And the coupling is proportional to the density of the beam. The growth rate of the wave produced by the electron beam are obtained. Then, the case of a relativistic electron beam guided by a longitudinal magnetic field in the same slow-wave structure is examined. The motion of electrons could be approximated to be one-dimensional when the simultaneous condition of the beam-wave interaction of dielectric Cherenkov maser is satisfied. Finally, the effect of the background plasma on the instability of the beam-wave interaction is studied. 相似文献
5.
利用自洽线性场理论,考虑电子的三维扰动,分析了环形相对论电子注在填充背景等离子体的介质筒慢波波导产生的切伦可夫辐射,其环形电子注对主波互作用的作用完全要用一跳变条件来描述,导出了其色散方程和波波互作用的同步条件,求得了是子注产生的波增长率,分析了背景等离子体密度和电子注半径对波增长率的影响。 相似文献
6.
利用线性场理论,对填充环形等离子体的介质切伦可夫脉塞进行了详尽的分析;讨论了薄环形相对论电子注包围环形等离子体、处于环形等离子体之间和位于环形等离子体之内,这三种情况下的注波互作用,分别导出了其色散方程;并对色散方程直接进行了数值求解;求得了系统的截止频率、工作频率和波增长率,讨论了有关参数对它们的影响。 相似文献
7.
Wu Jianqiang Song Liqun Liu Shenggang 《电子科学学刊(英文版)》1996,(3):249-256
The use of a background plasma in a dielectric Cherenkov maser can effectively increase the efficiency and the microwave output power of the device. Here, the effect of the longitudinal uniform magnetic field on the wave-beam interaction of the plasma-filled dielectric Cherenkov maser is examined by solving the beam-plasma, dielectric lined waveguide dispersion equation. And the effects of the longitudinal magnetic field, plasma density and dielectric parameters on the linear spatial growth rate and the energy ratio are presented. 相似文献
8.
Hiroshi Tsukuda Masaru Masuzaki Norio Toyosugi Cha Yeol Lee Ritoku Ando Keiichi Kamada Tsuguhiro Watanabe 《Journal of Infrared, Millimeter and Terahertz Waves》2001,22(8):1147-1162
A linear analysis is described on stabilities driven by an intense relativistic electron beam in an infinitely long, plasma-filled, and dielectric-lined circular waveguide immersed in a finite strength axial magnetic field. A dispersion equation is derived from the cold fluid theory and solved numerically. Beam-plasma instabilities due to interaction between beam modes and the Trivelpiece-Gould modes appear as well as the Cherenkov and the cyclotron Cherenkov instabilities. Parametric researches are carried out varying magnetic field strength, plasma density, and dielectric constant. Effects of a finite magnetic field and plasma filling are discussed in connection with the possibilities of using this system as a microwave radiation source. 相似文献
9.
10.
11.
利用自洽线性场理论:考虑电子的三维扰动,分析了轴向实心相对论电子注通过填充背景等离子体介质筒慢波波导产生的切伦可夫辐射,导出了描述其不稳定性的色散方程和注液互作用的同步条件,求得出电磁波辐射的时间增长率,分析了背景等离子体密度和实心电子注半径对波增长率的影响。 相似文献
12.
13.
Analysis and Calculations on Dispersion Relation and Coupling Resistance of Periodic Plasma-Cavities
The plasma tensor dielectric permittivity and electromagnetic field accurate expressions in the external axial magnetic field are obtained from the Maxwell’s equations and the double component plasma particle linear movement equations. Further, the flux of energy inside the plasma-cavity drift channel is presented. Based on them, some of the property of cavity passband dispersion and coupling resistance of plasma-filled coupled-cavities slow wave structure in different plasma density and magnetic field conditions is analyzed according to the numerical calculation. 相似文献
14.
15.
Murugan Sumathy Subrata Kumar Datta 《Journal of Infrared, Millimeter and Terahertz Waves》2017,38(5):538-547
A single-section slow-wave structure for a W-band folded-waveguide traveling-wave tube with operating bandwidth of around 4% was designed for delivering the output power of 50 W at the operating voltage of 13.5 kV and operating beam current of 80 mA. The design was carried out using analytical formulations and 3D electromagnetic simulations. The beam-wave interaction analysis was carried out using large signal Lagrangian analysis and particle-in-cell simulation. The folded-waveguide slow-wave structure along with input-output couplers and RF windows were fabricated. Cold test measurements were carried out for dispersion characteristics of the slow-wave structure and voltage standing-wave ratio and insertion loss characteristics of the RF window. The measured cold circuit parameters show close agreement with the analysis. 相似文献
16.
Zhigang Lu Yubin Gong Yanyu Wei Wenxiang Wang 《Journal of Infrared, Millimeter and Terahertz Waves》2006,27(8):1095-1108
A new type of partial-dielectric-loaded rectangular waveguide grating slow-wave structure (SWS) for millimeter wave traveling wave tube (TWT) is presented in this paper. The radio-frequency characteristics including the dispersion properties, the longitudinal electric field distribution and the beam-wave coupling impedance of this structure are analyzed. The results show that the dispersion of the rectangular waveguide grating circuit is weakened, the phase velocity is reduced and the position of the maximum E z is basically invariant after partially filling the dielectric materials in the rectangular waveguide grating SWS. Although the coupling impedance decreases a little, it still keeps above 40 Ω. 相似文献
17.
Characterized with full-metal structure, high output power and broad bandwidth, microfabricated folded waveguide is considered
as a robust slow-wave structure for millimeter wave traveling-wave tubes. In this paper, cold-test (without considering the
real electron beam) properties were studied and optimized by 3D simulation on slow-wave structure, for designing a 220 GHz
folded waveguide traveling-wave tube. The parametric analysis on cold-test properties, i.e., phase velocity, beam-wave interaction
impedance and cold circuit attenuation, were conducted in half-period circuit with high frequency structure simulator, assisted
by analytical model and equivalent circuit model. Through detailed parametric analyses, interference between specified structural
parameters is found on determining beam-wave interaction impedance. A discretized matrix optimization for interaction impedance
was effectively carried out to overcome the interference. A range of structural parameters with optimized interaction impedance
distributions were obtained. Based on the optimized results, a broadband folded waveguide with cold pass-band of about 80 GHz,
flat phase velocity dispersion and fairly high interaction impedance was designed for a 220 GHz central frequency traveling-wave
tube. A three-dB bandwidth of 20.5 GHz and a maximum gain of 21.2 dB were predicted by small signal analysis for a 28 mm-long
lossy circuit. 相似文献
18.
19.
M. P. Deichuli V. I. Koshelev 《Journal of Communications Technology and Electronics》2013,58(8):828-839
A multiwave Cherenkov generator with an asymmetric superdimensional slow-wave structure that generates the linearly polarized radiation is proposed and experimentally studied. The pulses of the linearly polarized radiation with a wavelength of 3.25 cm, a pulse duration of 30 ns, and a power of 850 MW are generated at electron energy of 470 keV and a beam current of 4.9 kA in a relatively weak magnetic field of 4.3 kG. It is demonstrated that the generation efficiency is 30% for almost Gaussian field distribution. 相似文献
20.
本文在考虑等离子体厚度效应的情况上,详尽地推导了充填圆环状等离子体的圓柱波导中TM模慢电磁波的色散方程;利用相对论空间电荷波理论,导出了相对论电子注在轴向磁场引导下沿等离子体内表面传输时的空间电荷波方程;求得了电子注和慢空间电荷波相互作用的线性增益和频率漂移;讨论了等离子体厚度、密度对色散特性和互作用增益的影响。 相似文献