Promising source of high-power broadband microwave pulses with radiation frequency variable up to two octaves

Ernyleva, S. E.; Litvin, V. O.; Loza, O. T.; Bogdankevich, I. L.

doi:10.1134/s1063784214080106

Cited by 6 publications

(3 citation statements)

References 8 publications

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“…The parameters of the problem are: magnetic field 𝐵 = 1 T = 10 4 Gs, diode length 𝐿 = 30 cm, cathode radius 𝑅 𝐶 = 1 cm, anode radius 𝑅 𝐴 = 2.72 cm, cathode potential 𝑈 = 511 kV = 1.70 ⋅ 10 3 CGS. For the current 𝐼 of a steady beam, the Fedosov's empirical law is valid (see [13] and the cited literature)…”

Section: Problem Statementmentioning

confidence: 99%

Numerical simulation of cold emission in coaxial diode with magnetic isolation

Белов

Loza

Lovetskiy

et al. 2022

Discrete and Continuous Models

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Due to the emergence and active development of new areas of application of powerful and super-powerful microwave vacuum devices, interest in studying the behavior of ensembles of charged particles moving in the interaction space has increased. An example is an electron beam formed in a coaxial diode with magnetic isolation. Numerical simulation of emission in such a diode is traditionally carried out using particle-in-cell methods. They are based on the simultaneous calculation of the equations of motion of particles and the Maxwell’s equations for the electromagnetic field. In the present work, a new computational approach called the point macroparticle method is proposed. In it, the motion of particles is described by the equations of relativistic mechanics, and explicit expressions are written out for fields in a quasi-static approximation. Calculations of the formation of a relativistic electron beam in a coaxial diode with magnetic isolation are performed and a comparison is made with the known theoretical relations for the electron velocity in the beam and for the beam current. Excellent agreement of calculation results with theoretical formulas is obtained.

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Section: Problem Statementmentioning

confidence: 99%

Numerical simulation of cold emission in coaxial diode with magnetic isolation

Белов

Loza

Lovetskiy

et al. 2022

Discrete and Continuous Models

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“…等离子体束的波导中激发的等离子体慢波发生契伦柯夫共振相互作用，使得电子束的能量向等离子体慢波转移，从而实现波的放大 [3,4] 。与为提高器件输出性能而填充等离子体的电真空相对论微波器件不同 [5][6][7] ，PRMG中的等离子体束是实现器件运行的必要条件，辐射频率的调节可以通过改变等离子体密度来实现。通过束波互作用区结构的设计和工作参数的选取，PRMG能以普通放大器或者振荡器形式工作, 如等离子体相对论微波放大器 [8] 或振荡器 [9] (PRMA，Plasma Relativistic Microwave Amplifier 或 PRMO ， Plasma Relativistic Microwave Oscillator)，也能够以噪声放大器的形式工作，即PRNA。PRNA可以产生超宽带微波辐射，与此同时，PRNA还具有输出功率高和可重复频率运行等潜质。因此，PRNA在脉冲雷达、通信、电子对抗、物体探测、地质以及医学等诸多领域均具有良好的应用前景 [10,11] 。与传统的利用快速开关直接把直流电能转换成微波输出的高功率超宽带电磁脉冲辐射源 [12] (EMPS，electromagnetic pulse sources)相比，PRNA具有以下优势：不同脉冲的辐射频率可以在较大范围内变化，且脉冲宽度不随中心频率的增加而缩短；单脉冲能量可以较大，甚至可以达到10焦耳 [13] 。当然，超宽带EMPS 无需相对论电子束,也就不需高能强流电子束源和真空电子设备,原理相对简单，成本较低。因此，我们可以根据实际需求，合理选取超宽带微波的产生方式。 PRNA的理论和实验研究以及输出性能的提升将可能为某些重要应用提供更适合的宽带微波源。与同属PRMG器件的其他器件相比，PRMA工作时需要微波种子源的激励， PRMO调频方式为阶跃型调频，不能在频率区间内连续调频，阶跃宽度主要由波束互作用区具体结构参数决定。PRNA则可以实现在连续频谱内的调频，且无需微波种子源和反馈机制，因此结构更加紧凑。但相对于PRMA和PRMO，PRNA 的提出相对较晚。2013年Ernyleva等学者首次提出了PRNA [14,15] ，数值模拟得到了频率范围为4-17GHz、带宽为2GHz、功率为150MW和效率为15%的微波输出。随后，科学家对PRNA进行了进一步的理论研究，模拟得到了频率范围2-12GHz、功率20MW、效率4-9% [16] 和频率范围3-9GHz、功率40MW、效率约8% [17] 的微波输出。2019年，文献 [13]首次进行了PRNA的实验研究。实验结果证实了PRNA 产生连续谱超宽带的可行性，并获得了单脉冲10J的微波能量，功率百MW量级，输出微波的中心频率可以通过改变等离子体束密度进行调节，频率范围为 2-3.5GHz。随后，通过进一步增加等离子体束密度，实验观察到微波中心频率可以从3GHz提高到25GHz [18][19][20] the relativistic electron beam, 3 is the plasma beam and 4 is the particle collector 模拟过程中具体参数的选取参考了相关的实验和文献 [14,15] ，除非另有说明，选取的基本参数为：互作用区半径R =1.8cm，收集极半径R 0 =1.2cm，环形等离子体束通过低能电子束电离气压约为10 -4 -10 -3 Torr惰性气体产生 [21] ，等离子体中组分为电子和氙离子，等离子体束半径、径向厚度和密度分别为 =1.05cm…”

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Physical analysis and numerical simulations of ultra wideband plasma relativistic microwave noise amplifier

Yang¹,

Dong²,

Sun³

et al. 2023

Acta Phys. Sin.

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The physical mechanism and output properties of the plasma relativistic microwave noise amplifier (PRNA) is studied numerically using the all electromagnetic PIC(Particle-in-Cell) code. Firstly, the dispersion relations between the operating mode and the slow space charge wave of relativistic electron beam without coupling are simulated and analyzed. Simulation results show that both the plasma density np and radial thickness Δrp affect the dispersion characteristics markedly and the frequency at the beam-wave resonant point increases with the increasing of them. The beam voltage and current also affect the resonant frequency, but the effect is relatively slight. Secondly, variations of the linear growth rates and the bandwidth are then evaluated using the linear theory. Calculations show that the PRNA has the virtue of wideband output. Its bandwidth can reach GHz level. By adjusting the plasma parameters np and Δrp, the relativistic electron beam voltage and current, the operating frequency can be tuned over a wide frequency range. Therefore the PRNA also has virtue of fine frequency tunability. Based on the above calculation results, the whole PIC simulations of the PRNA are then carried out to verify the virtues of wideband microwave output and frequency tunability. The basic features of the field distributions of the operating during the evolution and out coupling processes are given. The bunching and energy release process of relativistic electron beam are also plotted. Simulations show that with the plasma density of 1.4×1019/m3, the beam voltage and current of 500kV and 2kA and the applied magnetic field of 2.0 Tesla, 200MW output microwave with efficiency about 20% can be obtained. The frequency range is from about 7.0GHz to 9.0GHz, the band width reaches 2GHz. And the output mode is the TEM mode of the coaxial waveguide. Both np and Δrp affect the dispersion relations markedly and the output frequency increases clearly with the increasing of npand Δrp. The beam voltage and current affect the output frequency relative slightly and the gap distance between the plasma and electron beams has almost no effect on the output frequency. The research results will provide useful references for the further design of the PRNA.

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“…More accurate calculations directed to practical implementation of the proposed microwave oscillator will be performed taking into account the indicated weak longitudinal magnetic field using the particlein-cell method for all plasma electrons and ions, considering their motion, as was done, e.g., in [7]. Nevertheless, the possibility of developing the high-power microwave oscillator without strong magnetic field, i.e., with a comparatively high efficiency and, simultaneously, with wide radiation frequency tuning, was demonstrated by the results presented above.…”

mentioning

confidence: 99%

On the development of plasma relativistic microwave oscillator without strong magnetic field

Bogdankevich

Litvin

Loza

2016

Bull. Lebedev Phys. Inst.

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A method for generating microwave pulses with a power of ∼1 GW and a frequency controlled in a band from 2 to 15 GHz during the interaction of relativistic electrons with plasma without strong magnetic field is proposed in the numerical model. The combination of a broadband plasma relativistic microwave oscillator and a monochromatic magnetically insulated transmission line oscillator (MILO) allows the development of a device combining advantages of both prototypes.

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Promising source of high-power broadband microwave pulses with radiation frequency variable up to two octaves

Cited by 6 publications

References 8 publications

Numerical simulation of cold emission in coaxial diode with magnetic isolation

Numerical simulation of cold emission in coaxial diode with magnetic isolation

Physical analysis and numerical simulations of ultra wideband plasma relativistic microwave noise amplifier

On the development of plasma relativistic microwave oscillator without strong magnetic field

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