Relativistic backward wave oscillators (RBWOs) have the characteristics of high power and high repetition rate. Reducing the magnetic field strength and the weight of the external permanent magnet (PM) is a significant development direction of RBWOs. In previous research, an X-band RBWO enclosed with a PM has achieved a power efficiency of 50%. However, the PM used in these papers requires a magnetic field magnitude of over 0.68 T, which leads to a weight exceeding 400 kg. The RBWO designed in this paper operates in coaxial TM01 mode, and the radial distance between its cathode and the surface of the slow wave structures reaches 7 mm. Under the condition of a low magnetic field, this design can provide a wide electron beam channel to avoid the rubbing of the electron beam envelope on the inner and outer conductors. Particle-in-cell simulation results have demonstrated that this RBWO achieves an output microwave power of 3 GW with a power efficiency of 50% enclosed in a PM with a magnetic field strength of 0.43 T and a weight of 74 kg.

中文翻译：

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永磁封装X波段高效同轴相对论后向波振荡器设计


相对论后向波振荡器（RBWO）具有高功率、高重复率的特点。降低磁场强度和外部永磁体（PM）的重量是RBWO的一个重要发展方向。在之前的研究中，封装有PM的X波段RBWO已经实现了50%的功率效率。然而，这些论文中使用的永磁体需要超过 0.68 T 的磁场强度，这导致重量超过 400 kg。本文设计的RBWO工作在同轴TM01模式，其阴极与慢波结构表面之间的径向距离达到7 mm。在低磁场条件下，这种设计可以提供较宽的电子束通道，避免电子束包络线对内外导体的摩擦。粒子内模拟结果表明，该RBWO封装在磁场强度为0.43 T、重量为74 kg的PM中，可实现3 GW的输出微波功率，功率效率为50%。