Research of the Oscillation Start-Up Time in an Extended Interaction Oscillator Driven by a Pseudospark-Sourced Sheet Electron Beam

Ruibin Peng,Xuesong Yuan,Bin Wang,Liangjie Bi,Lin Meng,Xiaotao Xu,Che Xu,Qingyun Chen,Ping Zhang,Yong Yin,Hailong Li

doi:10.3390/electronics11040664

Ruibin Peng, Xuesong Yuan + Show 9 more

Open Access

https://doi.org/10.3390/electronics11040664

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Abstract

High current density and high brightness are critical factors for high-power and compact extended interaction oscillators (EIOs) which are operated in the terahertz (THz) waveband. The pseudospark-sourced (PS) sheet electron beam, which combines merits including high current density, a relatively big beam cross-section and no requirement for the external focusing magnetic field, is a good choice for application to high-frequency EIO. The pulse generated by the PS electron beam can last around tens of nanoseconds or even less, thus the EIO’s oscillation start-up time (OST) should be short enough. This paper researched how to reduce OST in an EIO driven by the PS sheet electron beam. The authors realized that the OST of EIO was very sensitive to the gap length under the equal period. The distribution of the electric field is optimized by adjusting the length of the gap. The strong electric field strength is conducive to the beam-wave interaction, and the OST is affected by the beam-wave interaction. When the gap length reaches a suitable value, the OST becomes the shortest. The simulation results showed the EIO’s shortest OST was 8 ns and the corresponding peak output power was 2 kW at 0.19 THz, while the current density was 500 A/cm2. When current density reached 10,000 A/cm2, the shortest OST could even be 1.9 ns.

Highlights

The millimeter-wave (MMW) and terahertz-wave radiation sources have a lot of useful applications, including biological spectroscopy, molecular spectroscopy, high data rate communications, security checks and material research [1,2,3]
The extended interaction oscillators (EIOs) at THz are in urgent need of power which is precisely focused and has a high current density electron beam
When the microwave devices are operated in the THz region, a quite high electron beam current density is essential

Summary

Introduction

The millimeter-wave (MMW) and terahertz-wave radiation sources have a lot of useful applications, including biological spectroscopy, molecular spectroscopy, high data rate communications, security checks and material research [1,2,3]. The EIOs at THz are in urgent need of power which is precisely focused and has a high current density electron beam. The PS electron beam has many noble advantages, such as a compact structure, high beam current density, low vacuum environment and no requirement for the external focusing magnetic field [12,13,14,15]. This research combines the PS electron beam’s advantage of a high current density and the sheet beam’s superiority of a large cross-sectional area to produce high-power millimeter-wave radiation [10,18]. This method is a suitable solution to generate high-frequency and high-power millimeter-wave, or even terahertz-wave radiation sources.

Characteristics of the EIO Driven by PS Electron Source

Simulation of the G-Band PS Sheet Electron Beam EIO