激光驱动含能复合飞片速度特性

Preparation and characteristics of laser-driven energetic composite flyer

采用真空磁控溅射方法制备了CuO/Al2O3/Al,(CuO/Al)Ⅱ/CuO/Al2O3/Al,(CuO/Al)Ⅷ/Al2O3/Al三种复合飞片,利用激光共聚焦显微镜和扫描电镜对复合飞片进行表征,结果表明,不同材料膜层的分界面清晰可见,复合薄膜的表面结构致密,颗粒基本尺寸可以达到nm级,均匀性好。利用光子多普勒测速技术对三种复合飞片速度进行测量,结果表明:将飞片靶放置在空气电离点偏前的位置(入射激光方向),增大聚焦光斑,能改善激光电离空气引起的能量屏蔽作用;含能烧蚀层CuO/Al的存在,有助于提高飞片速度。在含能薄膜烧蚀层厚度一定的情况下,增大周期、减小每层薄膜厚度,有助于提高含能薄膜反应程度,减小飞片上升沿时间。在同等激光能量密度下,(CuO/Al)Ⅷ/Al2O3/Al的上升沿时间低于(CuO/Al)Ⅱ/CuO/Al2O3/Al。

Vacuum magnetron sputtering technology was used to prepare three kinds of composite films：CuO/Al2O3/Al,（CuO/Al）Ⅱ/CuO/Al2O3/Al,and（CuO/Al）Ⅷ/Al2O3/Al,and the performance of the materials were characterized by scanning electron microscopy and confocal microscopy.The results showed that the surface of the films were smooth,and the interfaces between different layers were compact.Then,photonic Doppler velocimetry was used to measure the speeds of the flyers.The results showed that the flyers were placed in front of the position where the air was ionized by laser so that energy shielding effect caused by laser ionization of air could be improved.Besides,the energetic film as an ablative layer such as CuO/Al helped to improve the speed of flyers.When the thickness of the ablation layer was unchanged,the way of increasing cycle and reducing the film thickness of each layer was used to improve the degree of reaction and reduce the rising time.On the condition of the same laser energy density,that of（CuO/Al）Ⅷ/Al2O3/Al was less than that of（CuO/Al）Ⅱ/CuO/Al2O3/Al.