Moscow Institute of Physics and Technology (State University), Institutskiy pereulok str. 9, Dolgoprudny, Moscow region, 141701, Russia.
Institute for Spectroscopy RAS, Fizicheskaya str. 5, Troitsk, Moscow, 108840, Russia.
Sci Rep. 2018 Jan 12;8(1):597. doi: 10.1038/s41598-017-19140-w.
Targeting micrometer sized metal droplets with near-infrared sub-picosecond laser pulses generates intense stress-confined acoustic waves within the droplet. Spherical focusing amplifies their pressures. The rarefaction wave nucleates cavitation at the center of the droplet, which explosively expands with a repeatable fragmentation scenario resulting into high-speed jetting. We predict the number of jets as a function of the laser energy by coupling the cavitation bubble dynamics with Rayleigh-Taylor instabilities. This provides a path to control cavitation and droplet shaping of liquid metals in particular for their use as targets in extreme-UV light sources.
用近红外亚皮秒激光脉冲瞄准微米大小的金属液滴会在液滴内产生强烈的受约束的应力声波。球形聚焦会放大它们的压力。稀疏波会在液滴中心引发空化，空化会以可重复的成核碎裂模式爆炸性地膨胀，从而产生高速射流。我们通过将空化气泡动力学与瑞利-泰勒不稳定性相耦合，来预测射流的数量作为激光能量的函数。这为控制空化和特别是控制液态金属的液滴形状提供了一种途径，尤其是将它们用作极端紫外光源的靶材。
