激光辐照氮化硅陶瓷光谱信息研究北大核心CSCD

氮化硅陶瓷具备耐腐蚀、耐磨损和耐高低温冲击的优良性能,常用于高超声速飞行器的热防护材料,激光武器是未来高超声速目标拦截和打击的主要技术手段。采用Nd3+:YAG固体脉冲激光器作为辐照源,热压烧结氮化硅陶瓷为靶材,中阶梯光栅光谱仪为探测器搭建实验系统,采集激光波长1064 nm,脉宽15 ns,不同能量(50 mJ~500 mJ)作用靶材的辐射光谱。基于美国标准技术与研究院原子光谱数据库对谱线指认,利用玻尔兹曼斜线法计算得到等离子体电子温度范围为6203 K~6826 K,斯塔克展宽法计算等离子体电子密度范围为8.40×10^(15)cm^(−3)~1.14×10^(16)cm^(−3),等离子体电子振荡频率为8.23×10^(11)Hz~9.58×10^(11)Hz,随着激光能量增加电子温度整体呈上升趋势,电子密度变化存在波动。

Spectral information of silicon nitride ceramics irradiated by laser

Silicon nitride ceramics have excellent properties of corrosion resistance, wear resistance and resistance to high-low temperature impact, which are commonly used in thermal protection materials of hypersonic vehicles. The laser weapons are the main technical means for intercepting and striking the hypersonic targets in the future. The Nd3+:YAG solid-state pulsed laser was used as an irradiation source and hot-pressed sintered silicon nitride ceramic was used as the target. Meanwhile, the echelle grating spectrometer was used as the detector to construct an experimental system. The radiation spectra of the target with a laser wavelength of 1 064 nm, pulse width of 15 ns, and different energies (50 mJ~500 mJ) were collected. Line identification was based on the national institute of standards and technology (NIST) atomic spectrum database. According to the Boltzmann method, the plasma electron temperatures range from 6 203 K~6 826 K, the plasma electron density range calculated by the Stark broadening method is 8.40×1015 cm?3~1.14×1016 cm?3, and the electronic oscillation frequency is 8.23×1011~9.58×1011 Hz. With the increase of laser energy, the electron temperature demonstrates an overall upward trend, and the change of electron density fluctuates.