介绍了X射线脉冲星导航地面模拟光源研究的必要性及非伺服的机械调制方法所存在的问题和缺陷,提出了基于栅控X射线球管的X射线脉冲星辐射脉冲模拟方法,通过电子光学设计计算,对栅控X射线管的电极结构进行设计优化,研制了栅控X射线管和脉冲星模拟光源装置.实验测试了栅控球管的性能,测试结果与理论计算结果基本相符,实现了对X射线的调制;通过基于FPGA的直接数字频率合成方法,产生脉冲星的任意形状脉冲轮廓电压信号,加载至球管控制栅极,并对其出射脉冲轮廓进行测试,结果表明产生的X射线脉冲轮廓逼真程度在95%以上,模拟源频率稳定度约为2×10-11.
As an autonomous navigation method, X-ray pulsar navigation can provide position, timing and attitude information for various spacecrafts. Since the X-rays (1-20 keV) from the pulsar can not penetrate the earth atmosphere, an X-ray source in laboratory needs to be set up to test and calibrate the detector. In this paper an arbitrary X-ray pulse source to simulate the neutron pulsar signal is proposed. The main components of the simulation source are a grid controlled X-ray tube and arbitrary pulse generation electronics. With the arbitrary pulse voltage applied to the tube grid, the X-ray intensity is controlled. Through electron optics design, the tube electrode parameters are optimized. A grid controlled X-ray tube is fabricated and tested. Using a micro-channel plate detector to detect and reconstruct the generated X-ray pulses, the similarity between the accumulated profile and the original pulsar profile is better than 95%. The frequency stability of the pulsar source emulator is about 2 × 10-11.