Experimental Demonstration of a High-Efficiency Relativistic Magnetron With Diffraction Output With Spherical Cathode Endcap
Experimental Demonstration of a High-Efficiency Relativistic Magnetron With Diffraction Output With Spherical Cathode Endcap
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DOI：
10.1109/tps.2016.2644625
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发表时间：
2017-01
影响因子：
1.5
通讯作者：
C. Leach;S. Prasad;M. Fuks;J. Buchenauer;J. McConaha;E. Schamiloglu
中科院分区：
文献类型：
--
作者：
C. Leach;S. Prasad;M. Fuks;J. Buchenauer;J. McConaha;E. Schamiloglu
先前在新墨西哥州大学使用粒子单元代码MAGIC对具有衍射输出的相对论磁控管进行的计算研究达到了70%的效率。本文所述的研究旨在实现该设计的70%的有效操作的实验验证。拓扑结构的改变是必要的，例如引入亥姆霍兹式磁线圈对，以及在透明阴极的下游端使用抛光不锈钢端盖。这些结构在阳极-阴极间隙相互作用空间中保持高度的磁场均匀性，并拦截可能以其他方式影响电介质输出窗口的泄漏电子。这些结构的使用与其他人在保护窗户的工作中使用的修改磁场形成对比。将乙醇量热计和S波段波导检测器放置在近场中，以获得射频脉冲形状和频率，并通过测量辐射的总能量来推断峰值功率。使用同轴D点探针和自积分Rogowski线圈分别测量脉冲发生器电压和总电流，并显示管在63.5%的效率下工作，直到端盖开始发射电子，之后在$\pi $模式下效率为40.4%。捕获了在21 cm直径输出窗口外的灯泡网格和空气击穿的辐射场图案的图像，以确认$\pi $ -操作模式转换为TE 31圆形辐射输出模式。
A previous computational study of a relativistic magnetron with diffractive output at the University of New Mexico using the particle-in-cell code MAGIC achieved an efficiency of 70%. The research described in this paper aimed to achieve an experimental verification of 70% efficient operation of this design. Changes to the topology were necessary, such as the introduction of a Helmholtz-like magnetic coil pair and the use of a polished stainless steel endcap on the downstream end of the transparent cathode. These structures maintain a high degree of magnetic field uniformity in the anode–cathode gap interaction space and intercept leakage electrons that might otherwise impact the dielectric output window. The use of these structures stands in contrast to the modified magnetic fields used in the work of others to protect the window. An ethanol calorimeter and S-band waveguide detector were placed in the near-field to obtain radio frequency pulse shape and frequency and to infer peak power through a measurement of total energy radiated. A coaxial D-dot probe and self-integrating Rogowski coil were used to measure pulser voltage and total current, respectively, and showed that the tube operated at an efficiency of 63.5% until the endcap started emitting electrons, after which the efficiency was 40.4% in $\pi $ -mode. Images of radiated field pattern on a neon-bulb grid and of air breakdown outside of the 21-cm diameter output window were captured to confirm conversion of the $\pi $ -mode of operation to a TE31 circular radiated output mode.