中国工程物理研究院紧凑型自由电子激光太赫兹源装置采用了两路微波独立调谐热阴极微波电子枪作为注入器，一路由首腔馈入激励首腔和实现阴极表面建场并引出电子，另一路由后续腔馈入并通过腔间耦合激励各腔，两路微波互不耦合。对于这种微波激励方式，微波电子枪首腔的电场相位和幅度在实验中均可调节，因此可以通过实验研究来优化微波电子枪的工作参数，从而减小热阴极微波电子枪的电子反轰效应，提高束流品质。介绍了该热阴极微波电子枪热测实验研究的最新结果，通过BCT测得微波电子枪出口处束流强度超过400 mA，电子反轰效应随着首腔电场的相位和幅度调节发生显著变化，这些指标和实验现象与理论研究结果较为吻合

An independently tunable cells (ITC) thermionic cathode radio frequency (RF) gun is used as the injector for a compact FEL terahertz source in CAEP, and it is driven by microwaves through dual feed-in ports. One microwave feed-in port is located at the first cavity to excite the cavity and draw electron out from the cathode surface. Another is located at the last cavity to excite the rest cavities through coupling holes, There is no electromagnetic coupling between the two microwave feed-in ports. With regard to this kind of microwave working, the phase and amplitude of the electric field in the first cavity can be adjustable independently.Therefore the power of the back electron bombardment of the RF gun can be optimized and decreased by means of experimental research. Further more, higher quality beam can be obtained.The updated results about the power test on the thermionic cathode RF gun is introduced in this paper. A beam intensity about 400 mA is measured by beam-current transformer at the exit of the RF gun. And the effect is studied that back electron bombardment could be changed with adjustment of phase and amplitude of the electric field in the first cavity. The test results and phenomenon agree well with the theoretical design ones.