脉冲软X射线汽化喷射冲量

Vaporized blow-off impulse induced by pulse soft X-ray

在"强光一号"脉冲加速器上进行了实验室软X射线辐照铝材料的喷射冲量实验。实验得出:在能量分布为0.1~1.2keV、脉冲宽度为34~63ns、能注量为48~156J/cm2的X射线辐照下,对铝材料,其冲量耦合系数为0.44~0.76Pa·s/(J·cm-2)。采用汽化模型,假定沉积能量平均分配为质点的动能和内能,给出了汽化冲量的解析计算公式。计算表明:(1)软X射线存在产生汽化喷射冲量的能注量阈值,随着X射线能量的增大,能注量阈值也增大;(2)软X射线的汽化喷射冲量耦合系数有一极值点,在能注量阈值和极值点之间,耦合系数随能注量增大而增大,超过极值点后耦合系数随能注量的增加而减小;(3)解析计算和实验结果符合较好,本文计算方法可靠有效。

The blow-off impulses induced by soft X-ray were studied on the'Qiangguang I'accelerator.The experimental results show that the coupling coefficient of aluminum is in the range from 0. 44to 0.76Pa·s/(J·cm-2),when it is irradiated by pulse X-ray,the energy of which is 0.1-1.2 keV,the pulse width of which is 34-63ns and the energy fluxes of which are 48-156J/cm2.Provided one half of the deposited energy is delivered to the movement and adopted vaporized model,the analytical calculating formula of blow-off impulse is given.The calculated results show that:(1) there is an energy flux threshold of generating vaporized blow-off impulse,the energy flux threshold becomes bigger while the energy of X-ray increases;(2)there is a saturation point for the coupling coefficient of blow-off impulse,the coefficient increases with the increasing of the energy flux before this point,and it decreases slightly with the increasing of the energy flux after the saturation point;(3)the analytical results agree well with the experimental data,it means that the analytical method is reliable and effective.