为了研究医学系统中乳腺癌早期诊断的关键技术, 研制了一台用于准点X光源成像实验台架。该实验台架由脉冲触发器电源和脉冲X射线管组成, 其中脉冲触发器电源由Marx发生器、火花隙开关、电容分压器及输出段构成, 采用紧凑可移动化的设计; 脉冲X射线管利用冷阴极反射轰击阳极靶韧致辐射出X射线的机理, 该方法可有效提高辐射出X射线点源位置的重复率, 并且根据不同的驱动电压可调节阴阳极的材料及距离, 保证在脉冲X射线管输出X射线光子能量≥15 keV的情况下, X射线点源尺寸可以达到≤100 μm的设计指标。Simplorer模拟结果表明: 在脉冲X射线管阻抗为57 Ω时, 脉冲触发器输出指标为电压169 kV, 上升时间≤10 ns, 脉宽≤100 ns。

In order to study the key technology of early diagnosis of breast cancer in medical system, an X-ray imaging test bench for punctual X-ray source is developed. The test bench consists of a pulsed power trigger and a pulsed X-ray tube. The pulsed flip-flop power supply consists of a Marx generator, a spark gap switch, a capacitive voltage divider and an output section. Pulsed X-ray tube utilizes the mechanism of cold cathode reflection bombarding anode target to emit X-ray. This method can effectively improve the repetition rate of radiated X-ray point source position, and adjust the material and distance of cathode and anode according to different driving voltage to ensure the output of X-ray photon energy in the pulse X-ray tube. In the case of more than 15 keV of X-ray photon energy, the size of the X-ray point source can reach the design index of less than 100 μm. Simplorer simulation results show that when the impedance of the pulsed X-ray tube is 57 Ω, the output voltage of the pulse trigger is 169 kV, the rise time is less than 10 ns, and the pulse width is less than 100 ns.