500 kV亚纳秒脉冲X光机研制

高能量亚纳秒脉冲X射线可用于精确定标辐射探测系统的时间响应特性和探测灵敏度，对于脉冲辐射场诊断技术研究具有重要意义。研制了一种小型化、可移动的亚纳秒脉冲X射线源，装置占地区域尺寸为1.2 m×40 cm，重142 kg。设计了双锥形绕组同轴结构变压器，采用新颖的三谐振变压技术，将纳秒脉冲形成线充电至520 kV，通过油介质自击穿开关放电，输出370 kV，3.8 ns的高压脉冲。设计了多级过匹配传输线提升输出电压，并利用油介质peaking-chopping开关进行脉冲压缩，产生了峰值520 kV、半高宽0.5 ns、功率1.8 GW的高压脉冲。基于Child-Langmuir定理，设计了刀刃阴极X光管，在520 kV电压下的运行阻抗为150 Ω，管前20 cm处的X射线峰值能量注量率约为1×1016 MeV·cm-2·s-1，累积照射量为4.1 mR。

Design of 500 kV sub-nanosecond pulsed X-ray generator

Sub-nanosecond high energy X-ray source is widely used in calibration of time response characteristic and sensitivity of radiation detectors. A compact generator for sub-nanosecond X-ray pulse was developed, covering a floor area of 1.2 m×40 cm with weight of 142 kg. A coaxial pulsed transformer was designed using double conical windings and triple resonance transformer technology. A nanosecond pulse forming line and a self-break oil switch were employed, generating a high voltage pulse with peak value of 370 kV and pulse width of 3.8 ns. The voltage was then increased to 520 kV by multi-stage over-matched transmission lines, and the pulse width was sharpened to 0.5 ns via a peaking-chopping oil switch. The power of the pulse loaded across the AK gap of the X-ray tube was 1.8 GW. The X-ray tube, using a foil array cathode, was designed and analyzed on the basis of Child-Langmuir theory. Radiation with a peak energy flux rate of about 1×1016 MeV·cm-2·s-1 was generated at a distance of 20 cm, and the integral dose was 4.1 mR per pulse.