Guo Liming, Shu Ting, Li Zhiqiang, Ju Jinchuan, Fang Xiaoting
College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, People's Republic of China.
Rev Sci Instrum. 2017 Feb;88(2):024708. doi: 10.1063/1.4975831.
Among high power microwave (HPM) generators without guiding magnetic field, Cerenkov-type oscillator is expected to achieve a relatively high efficiency, which has already been realized in X-band in our previous simulation work. This paper presents the preliminary experimental investigations into an X-band Cerenkov-type HPM oscillator without guiding magnetic field. Based on the previous simulation structure, some modifications regarding diode structure were made. Different cathode structures and materials were tested in the experiments. By using a ring-shaped graphite cathode, microwave of about one hundred megawatt level was generated with a pure center frequency of 9.14 GHz, and an efficiency of about 1.3%. As analyzed in the paper, some practical issues reduce the efficiency in experiments, such as real features of the electron beam, probable breakdown regions on the cathode surface which can damage the diode, and so forth.
在没有引导磁场的高功率微波（HPM）发生器中，切伦科夫型振荡器有望实现相对较高的效率，这在我们之前的模拟工作中已在X波段实现。本文介绍了对一种无引导磁场的X波段切伦科夫型HPM振荡器的初步实验研究。基于之前的模拟结构，对二极管结构进行了一些修改。在实验中测试了不同的阴极结构和材料。通过使用环形石墨阴极，产生了约100兆瓦级的微波，纯中心频率为9.14GHz，效率约为1.3%。正如本文所分析的，一些实际问题降低了实验效率，如电子束的实际特性、阴极表面可能的击穿区域会损坏二极管等。
