8km/s激光驱动飞片发射技术实验研究

Experimental research on laser-driven flyer plates up to 8km/s

实验研究了激光驱动飞片技术中激光能量剖面和飞片靶金属膜层的力学特性对飞片的速度和完整性的影响,认为激光能量剖面整体呈"平顶型"的光束是发射高质量飞片的基础,同时飞片靶的膜基附着力、金属膜层的强度和韧性三者之间应保持良好的匹配才能得到完整的飞片。制备了基底/Cr/Al复合结构飞片靶,利用波长1 064nm、脉宽15ns的激光,将直径1mm、厚度3μm的铝飞片稳定驱动至8km/s。

Aimed to the laser-driven flyer plate technique, laser-driven flyer experiments were conducted by using single pulsed laser beams at 1 064 nm, of 15 ns duration and up to 2 J energy to explore the influences of the laser energy profiles as well as the mechanical properties of the metal foils on the velocities and integrities of the flyers. The experimental results indicate that the laser beams with ＂top hat＂ energy profiles are key and important base to launch the flyers with good qualities. There exists a good matching among the adhesion of the foil to the glass substrate, the shear strength and tenacity of the foil, for obtaining a high-velocity and good-integrity flyer. By using the combined flyer target with a thin layer of chromium sandwiched between the aluminum foil and the glass substrate, the aluminum flyers with 1 mm in diameter and 3μm in thickness were accelerated to 8 km/s, and the experimental repeatabilities were good.