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Title: Novel high-power subterahertz-range radial surface wave oscillator

Abstract

A novel high-power subterahertz-range radial surface wave oscillator (SWO), in which the electron beam is emitted radially and interacts with the slow wave structure (SWS) machined on a planar plate, is presented in this paper. Compared to the axial SWO where the electron beam is emitted axially and interacts with the SWS machined on the inner wall of a cylindrical waveguide, the radial SWO has two advantages. One is that fabrication of the radial SWS is much easier than that of the axial SWO. The other is that the radial SWO is a low-impedance device, it can produce much higher current than the axial SWO when they are driven by the same driven voltage, and hence, it may generate much higher output power. Particle-in-cell simulation results demonstrate that the proposed radial SWO driven by the voltage of 312 kV can produce the terahertz wave with the mean output power of 680 MW at the frequency of 0.142 THz, it has a very pure TM{sub 01} mode and the higher modes can be effectively suppressed.

Authors:
;  [1];  [2]; ; ; ;  [1]
  1. Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China)
  2. (China)
Publication Date:
OSTI Identifier:
22490946
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPUTERIZED SIMULATION; CYLINDRICAL CONFIGURATION; ELECTRIC POTENTIAL; ELECTRON BEAMS; EMISSION; IMPEDANCE; OSCILLATORS; POWER GENERATION; THZ RANGE; WAVE PROPAGATION; WAVEGUIDES

Citation Formats

Chen, Zaigao, Wang, Jianguo, E-mail: wangjianguo@nint.ac.cn, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024, Wang, Yue, Wang, Guangqiang, Li, Shuang, and Cheng, Guoxin. Novel high-power subterahertz-range radial surface wave oscillator. United States: N. p., 2015. Web. doi:10.1063/1.4923287.
Chen, Zaigao, Wang, Jianguo, E-mail: wangjianguo@nint.ac.cn, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024, Wang, Yue, Wang, Guangqiang, Li, Shuang, & Cheng, Guoxin. Novel high-power subterahertz-range radial surface wave oscillator. United States. doi:10.1063/1.4923287.
Chen, Zaigao, Wang, Jianguo, E-mail: wangjianguo@nint.ac.cn, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024, Wang, Yue, Wang, Guangqiang, Li, Shuang, and Cheng, Guoxin. Mon . "Novel high-power subterahertz-range radial surface wave oscillator". United States. doi:10.1063/1.4923287.
@article{osti_22490946,
title = {Novel high-power subterahertz-range radial surface wave oscillator},
author = {Chen, Zaigao and Wang, Jianguo, E-mail: wangjianguo@nint.ac.cn and Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 and Wang, Yue and Wang, Guangqiang and Li, Shuang and Cheng, Guoxin},
abstractNote = {A novel high-power subterahertz-range radial surface wave oscillator (SWO), in which the electron beam is emitted radially and interacts with the slow wave structure (SWS) machined on a planar plate, is presented in this paper. Compared to the axial SWO where the electron beam is emitted axially and interacts with the SWS machined on the inner wall of a cylindrical waveguide, the radial SWO has two advantages. One is that fabrication of the radial SWS is much easier than that of the axial SWO. The other is that the radial SWO is a low-impedance device, it can produce much higher current than the axial SWO when they are driven by the same driven voltage, and hence, it may generate much higher output power. Particle-in-cell simulation results demonstrate that the proposed radial SWO driven by the voltage of 312 kV can produce the terahertz wave with the mean output power of 680 MW at the frequency of 0.142 THz, it has a very pure TM{sub 01} mode and the higher modes can be effectively suppressed.},
doi = {10.1063/1.4923287},
journal = {Physics of Plasmas},
number = 6,
volume = 22,
place = {United States},
year = {Mon Jun 15 00:00:00 EDT 2015},
month = {Mon Jun 15 00:00:00 EDT 2015}
}
  • Overmoded O-type Cerenkov generators using annular electron beams are facing the problem of multi-modes output due to the inevitable structural discontinuities. A simple but effective method to achieve the pure TM{sub 01} mode output is applied on the 0.14 THz overmoded surface wave oscillator (SWO) in this paper. In spite of still using an overmoded slow wave structure to ensure the easy fabrication, the followed smooth circular waveguide is shrinkingly tapered to the output waveguide with appropriate radius that it cuts off other higher modes except TM{sub 01} mode. Moreover, the modified device here has the same power capacity as themore » previous one according to the numerical analysis. By optimized lengths of the transition waveguide and tapered waveguide, particle-in-cell simulation results indicate that the subterahertz wave with output power increased 14.2% at the same frequency is obtained from the proposed SWO under the previous input conditions, and importantly, the output power is all carried by TM{sub 01} mode as expected. Further simulation results in the pulse regime confirm the feasibility of the optimized structure in the actual experiments. This simple and viable design is also applicable to overmoded devices in the lower frequency band of subterahertz wave.« less
  • A novel radial relativistic backward wave oscillator with a reflector is proposed and designed to generate GW-level high power microwaves at Ka-band. The segmented radial slow wave structure and the reflector are matched to enhance interaction efficiency. We choose the volume wave TM{sub 01} mode as the working mode due to the volume wave characteristic. The main structural parameters of the novel device are optimized by particle-in-cell simulation. High power microwaves with power of 2 GW and a frequency of 29.4 GHz are generated with 30% efficiency when the electron beam voltage is 383 kV, the beam current is 17 kA, and themore » guiding magnetic field is only 0.6 T. Simultaneously, the highest electric field in the novel Ka-band device is just about 960 kV/cm in second slow wave structure.« less
  • A unique, high-power microwave source, called PASOTRON[trademark] (Plasma-Assisted Slow-wave Oscillator), has been developed. The PASOTRON utilizes a long-pulse E-gun and plasma-filled slow-wave structure (SWS) to produce high-energy microwave pulses from a simple, lightweight device that utilizes no externally-produced magnetic fields. The novel E-gun employs a low-pressure glow discharge to provide a stable, high current-density electron source. A high-perveance, multi-aperture electron accelerator produces an E-beam that is operated in the ion-focused regime; where the beam-produced plasma filling the SWS space-charge neutralizes the beam, and the self-pinch force compresses the beamlets to provide propagation through the SWS. The PASOTRON E-gun has producedmore » beams with voltages of up to 220 kV and currents in excess of 1 kA for pulse lengths of over 100 [mu]sec. The PASOTRON HPM source normally operates in the TM[sub 01] mode, and a unique mode converter has been developed to efficiently produce a TE[sub 11] output mode with fixed polarization. The PASOTRON also has the ability to directly produce TE-mode radiation with a rotating output polarization. PASOTRON HPM sources have operated in L, S, C and X-bands, and have produced output powers in the 1 to 5 MW range in C-band at about 20% efficiency with pulse lengths of over 100 [mu]sec.« less
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