【摘要】 文中探测了硅靶在波长为1.064μm、脉宽10ns的脉冲激光辐照下等离子体时间分辨发射光谱,分析了电子温度、电子密度和连续谱的演化。利用能级寿命和连续谱最大强度的出现时间解释了NⅡ399.5nm、SiⅡ385.6nm和SiⅡ386.3nm谱线强度最大值的出现时间。NⅡ399.5nm谱线的寿命比Si II谱线的寿命要短得多,我们认为这和它们的产生过程有关。在1Pa的背景气压下能够探测到Si III和Si IV的光谱线,而在1.01×105Pa时却无法分辨。更多还原

【Abstract】 Time-resolved emission spectrum from laser-induced plasmas by 1.064 μm,10 ns laser pulse’s irradiation on silicon target surface is recorded and analyzed.The evolvement of electron temperature,electron density and continuous spectra is investigated.The appearance times of maximal signal of N II 399.5 nm,Si II 385.6 nm and Si II 386.3 nm can be explained by their lifetimes of upper energy level and appearance times of maximal signal of continuous spectra.It is found that the lifetime of N II 399.5 nm is shorter than that of Si II,which is owing to their different generation processes.In addition,spectrum lines of Si III and Si IV are observed at 1 Pa,but can’t be observed at 1.01×105 Pa.更多还原