1 MV杆箍缩二极管辐射特性实验研究

依据现有的实验室驱动源能力建立杆箍缩二极管（RPD）粒子模拟计算模型，获得了工作电压为1 MV的RPD电参数特性及电子、离子时空分布特性，并设计了RPD实验装置。在1 MV驱动源平台上开展了实验研究，实验中采用B dot、D dot、热释光剂量片和SiPin二极管测试了RPD电流、电压、辐射剂量和光脉冲信号，分析了RPD电参数及X射线辐射特性。结果表明，阳极采用1.5 mm钨时，1 MV电压下1 m处辐射剂量约1 R，并得出剂量与电压Ud、电流Id的关系式D(R=1 m)=120U1.55d∫Iddt；二极管阻抗范围为26.4~36.7 Ω，空间电荷限制阶段平均阻抗下降率大于2 Ω/ns，磁绝缘阶段平均阻抗下降率小于0.5 Ω/ns；光脉冲宽度较电压脉冲宽度约缩短20%~30%，与电压、电流的关系为∝IdU1.55 d。实验测试的剂量和光脉冲信号结果与拟合计算式计算结果符合较好。

Experimental Study of Rod Pinch Diode as Radiography Source at 1 MV

The rod pinch diode is a cylindrical pinched beam diode that provides an intense small diameter bremsstrahlung source for radiography. For this work, according to particle-in-cell results and the pulse power generator parameters, the 1 MV rod pinch diode was designed and studied experimentally. The experimental data were obtained on the 1 MV facility between 0.8 MV and 1 MV at 20 to 40 kA with 120 ns FWHM. The diode impedance behavior was studied. The average time rate of change of the diode impedance is less than 0.5 Ω/ns at magnetically limited stage and more than 2 Ω/ns at space charge limited stage. The diode impedance is between 26.4 Ω and 36.7 Ω. The dose of 1 R at 1 m is obtained with 1.5 mm anode. Dose obtained by experiment can be fitted by voltage Ud and current Id as D(R=1 m)=120U1.55d∫Iddt. The X-ray pulse width is proportional to IdU1.55d.