A medium-power broadband-tuning terahertz (THz) gyrotron operating at low voltages is especially attractive for applications in biomedicine. This article tends to elaborate on the challenges related to startup oscillation and ohmic loss suppression of an extremely low-voltage THz gyrotron. High interaction efficiency is achievable by applying long transit time of electrons to compensate the unfavorable decline of the beam-wave coupling strength for low-energy electron beams. A cavity structure which favors backward-wave interaction is proposed to extend the frequency tuning range. The theoretical study predicts that the optimal cavity contributes to the robust frequency tunability at low voltages. The results indicate that a continuous tuning range of 10.7 GHz around the 330-GHz band with output power higher than 1 W can be expected by utilizing a 0.3 kV, 0.5 A helical electron beam.

中文翻译：

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具有上行输出的太赫兹超低压回旋管


在低电压下工作的中等功率宽带调谐太赫兹（THz）回旋管对于生物医学应用尤其有吸引力。本文旨在详细阐述与极低压太赫兹回旋管的启动振荡和欧姆损耗抑制相关的挑战。通过应用电子的长渡越时间来补偿低能电子束束波耦合强度的不利下降，可以实现高相互作用效率。提出了一种有利于后向波相互作用的腔体结构来扩展频率调谐范围。理论研究预测，最佳腔有助于低电压下稳健的频率可调谐性。结果表明，利用 0.3 kV、0.5 A 螺旋电子束，可以实现在 330 GHz 频段周围 10.7 GHz 的连续调谐范围，输出功率高于 1 W。