一台基于串级二极管技术的高强度脉冲硬X射线源

介绍了利用串级二极管产生高强度脉冲硬X射线的方法及其辐射场参数。以“闪光二号”加速器为平台，通过适应性改造，产生快前沿电压脉冲；研制了两级阻抗1 Ω串级二极管，通过串联分压降低二极管端电压、各级二极管电子束独立打靶在空间叠加形成高强度均匀辐射场。解决了悬浮电极绝缘支撑、二极管阴极均匀发射等技术难题，实现了串级二极管的稳定工作。在总电压约700 kV、电流约310 kA条件下，X射线平均能量87 keV，500 cm²上的平均能注量36 mJ/cm²，剂量均匀性（最大值比最小值）达到2∶1。

An intense pulsed hard X-ray source based on series diode technology

There are formidable difficulties to generate intense pulsed hard X-ray. The lack of high fidelity high fluence X-ray source has become a restriction factor of SGEMP effect research. The method for intense large-area pulsed hard X- ray production by using a series diode and the radiation parameters are presented in this paper. Flash II accelerator was refined to generate a fast rise time voltage pulse, and a two-stage series diode was developed for coupling electrical energy of high-voltage generator to a low endpoint voltage bremsstrahlung diode via two diodes in series. The X-rays generated by each diode added in space to improve intensity. A dynamic support system was invented to solve the insulation problem of the floating electrode and double-ring cathodes were designed to improve emission uniformity. The experimental results show that the two-stage series diode can work stably under ～700 kV voltage and ～310 kA current, the average energy of X rays is 87 keV, and the fluence is about 36 mJ/cm2 over 500 cm2 area with dose uniformity 2∶1 at 5 cm from the last converter.