长脉冲X波段多注相对论速调管放大器的初步实验研究

Experimental study on a long pulse X-band coaxial multi-beam

设计了工作在长脉冲的X波段同轴强流多注相对论速调管放大器,对长脉冲强流多注电子束在多注器件结构中的传输、电子束经过输入腔和中间腔后的束流调制以及经过输出腔的微波提取等过程进行了实验研究,采用了相应的设计措施以减轻实验中出现的脉冲缩短现象,得到了初步的长脉冲实验结果.在输入微波功率60 k W、频率9.378 GHz、电子束电压700 k V、束流4.2 k A、轴向引导磁感应强度1 T的条件下,重频5Hz输出微波功率为670 MW,脉宽89 ns,效率为23%,增益为40 d B,输出微波频率与输入微波一致.从实验上验证了几十千瓦级输入微波驱动X波段同轴多注RKA输出几百兆瓦长脉冲高功率微波的可行性,为后续更高功率研究打下了基础.

An X-band coaxial multi-beam relativistic klystron amplifier is designed in order to increase the output microwave power and the operating frequency of the amplifier tube. Based on the results from PIC simulation, the experiment is performed on the long pulse accelerator. In the experiment, the transmittal and bunching of electron beam are analyzed, and then the amplifier is driven by a beam of 4.2 kA at 700 kV and an external source injects microwave power of 60 kW into an input cavity, then 670 MW microwave power of 5 Hz repeating frequency is extracted, the amplifier gain is about 40 dB, the pulse width is 89 ns, and the conversion effciciency is 23%. The experiment proves that several tens kW-level input power can drive the X-band coaxial multi-beam relativistic klystron amplifier to generate several hundred MW-level long pulse output power.