摘要
激光驱动飞片技术具有产生的飞片速度高、成本低、装置简单等传统动高压加载技术无法取代的优点.随着激光技术的发展,利用高功率激光脉冲发射高速飞片受到越来越多的关注.本文介绍了在神光Ⅲ原型装置上开展的激光驱动高速飞片实验研究.利用纳秒短脉冲和纳秒整形长脉冲,设计并开展了几种不同方式加速飞片的实验研究,成功获得了10 km·s^(-1)的固态铝飞片和50 km·s^(-1)超高速度的复合金属飞片,而且飞片具有良好的平面性和完整性.对实验的物理设计、技术途径和数据结果进行了比较全面的分析,为进一步开展激光驱动高速飞片相关实验研究提供了思路,同时也证明了神光Ⅲ原型装置在激光驱动高速飞片实验研究方面有着巨大的潜力.
Laser-driven flyers have unique advantages of high flyer velocity,low cost,simple facility compared with the flyers driven by other conventional dynamic high-pressure loading techniques.With the fast development of laser technique,launching hypervelocity flyers with high-intensity laser pulse has become more and more prevalent.In this paper,we introduce the recent experiments of laser-driven flyers at the SG-III prototype laser facility.Three ways of launching hypervelocity flyers are developed and introduced,respectively.In the first way,multilayered aluminum flyers are gradually accelerated to a terminal velocity of 8 km/s,which is measured by optical velocimetry,without melting and vaporization.The pressure distribution within the flyer shows that the temporally ramped pulse ablation generates a compression wave,and the flyer is accelerated by this wave and its reverberation within the flyer.In the second way,a strong laser ablates the low-density reservoir foil and generates strong shock in the foil.The shock wave is strong enough,and when the shock breaks out from the free surface,the foil will unload as plasma towards the flyer with a density profile.The plasma decelerates upon colliding the flyer,and the single-layered flyer is gradually accelerated by the momentum transition.In our experiments,single-layered aluminum foil and single-layered tantalum foil are accelerated to 11.5 km/s and 6.5 km/s,respectively.According to the pressure distribution within the flyer,the flyer is also accelerated by the compression wave produced by the plasma collision,which is similar to the case of direct ablation by temporally ramped pulse.However,the way of plasma collision could better reduce X-ray and electron preheat and obtain cleaner flyers.In the last way,the flyers are launched by direct strong short-laser ablation.The multi-layered aluminum foil is accelerated to a high average velocity of 21.3 km/s by using a 3-ns quadrate laser pulse at 351 nm after spatial homogenization.A line-velocity interferometer system fo
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2017年第6期164-172,共9页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11504349)
中国工程物理研究院重点实验室基金(批准号:9140C680305140C68289)资助的课题~~
关键词
冲击波
激光驱动飞片
动高压物理
等离子体
shock wave
laser-driven flyers
dynamic high-pressure physics
plasma
