基于Z箍缩X射线源的热-力学效应实验  

Experiments for thermomechanical effects based on Z-pinch X-ray sources

作　　者：张朝辉[1] 张思群[1] 任晓东[1] 王贵林[1] 黄显宾[1] 周少彤[1] 王昆仑[1] 徐强[1] 蔡红春[1] ZHANG Zhaohui;ZHANG Siqun;REN Xiaodong;WANG Guilin;HUANG Xianbin;ZHOU Shaotong;WANG Kunlun;XU Qiang;CAI Hongchun(Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621999,Sichuan,China)

机构地区：[1]中国工程物理研究院流体物理研究所,四川绵阳621999

出　　处：《爆炸与冲击》2021年第9期75-82,共8页Explosion and Shock Waves

基　　金：国家自然科学基金(11605188,11905208)。

摘　　要：材料或结构对强脉冲X射线的响应如热激波的传播和喷射冲量等,统称为X射线热-力学效应,在抗辐射加固研究、天体物理、行星科学等领域具有重要应用。利用驱动电流近10 MA脉冲功率装置上的丝阵Z箍缩X射线源开展了初步的热-力学效应实验。采用20 mm直径的双层铝丝阵产生了约230 kJ的X射线总辐射能,其中铝的K壳层产额约为30 kJ,距离源中心5 cm处的样品上的X射线能注量为732 J/cm^(2)。受辐照样品为厚度2 mm、直径10 mm的铝制圆盘,其背面设置有铝衬套,样品与衬套的总质量为585 mg。采用全光纤光子多普勒测速(PDV)系统来测量受辐照样品后表面的运动过程。PDV测量的样品后表面速度历程显示,当热激波到达后表面时的自由面速度为2.12 km/s,样品最终的整体运动速度为180 m/s。根据冲击波关系式以及动量守恒原理,推导出X射线在样品中产生的热激波应力为19.2 GPa,单位面积上的喷射冲量为1341 Pa·s,进而由喷射冲量和X射线能注量测量结果可以推出冲量耦合系数为1.83 Pa·s·cm^(2)/J。同时,对实验测量结果的可靠性和不确定度进行了讨论和分析。这些实验结果初步验证了将PDV技术应用于热-力学效应研究的可行性。Responses of materials and structures to intense pulsed X-ray radiation,such as thermal shock wave propagation and blowoff impulse generation are referred to collectively as X-ray thermomechanical effects,which have been applied to radiation hardening,astrophysics,and planetary science.Preliminary experiments for thermomechanical effects have been performed utilizing wire array Z-pinch X-ray sources on a pulsed power facility with a drive current of about 10 MA.A total X-ray radiation energy of about 230 kJ was produced by a nested aluminum wire array of 20 mm in outer diameter,and the K-shell yield of about 30 kJ for aluminum was measured.An X-ray energy fluence up to 732 J/cm^(2)was produced on an irradiated target which was positioned at 5 cm away from the X-ray source center.The irradiated target was an aluminum disk 2 mm in thickness and 10 mm in diameter,backed by an aluminum liner.The total weight of the disk and liner was 585 mg.An all-fiber photonic Doppler velocimeter(PDV)was used to monitor the motion of the rear surface of the irradiated target.The velocity history measured by PDV suggested a free-face velocity of 2.12 km/s when the shock wave arrived at the rear surface of the target,and the final velocity of the target is 180 m/s.Based on the Hugoniot relationships and the law of momentum conservation,a stress of the thermal shock wave of 19.2 GPa and a blowoff impulse per unit target area of 1341 Pa·s were deduced.Furthermore,a consequent coupling coefficient of 1.83 Pa·s·cm^(2)/J was estimated from the measurements of blowoff impulse and the X-ray energy fluence.Finally,discussions on the reliability and uncertainty of the measurement were presented.These experimental results described here preliminarily validated the feasibility of the application of PDV to the research of X-ray thermomechanical effect.

关 键 词：Z箍缩X射线源 热-力学效应 光子多普勒测速 热激波 喷射冲量 

分 类 号：O536[理学—等离子体物理]