【摘要】 阐述了激光诱导离解光谱分析技术的工作机理。基于Nd∶YAG激光器和CCD器件多通道光栅光谱仪,建立了一套激光诱导离解光谱探测实验装置,针对激光脉冲能量,延迟探测时间,周围气体压强对LIBS探测性能的影响开展了相应的实验研究,实验结果证明:在较低脉冲能量下也可以获得原子光谱信号;适当调节延迟探测时间可以获得最佳的探测信噪比,某些样品几乎不辐射出强的背景连续谱,可以省去延迟探测;在5×10-5Pa的低压条件下仍然可以获得信噪比较高的原子光谱信号,但信号的强度与大气气压相比明显变小;通过对低压样品室中高纯度样品的探测分析获取标准原子谱线,与未知样品的原子谱线比较以消除系统识别误差,从而准确识别出未知样品中的组成元素。更多还原

【Abstract】 The working principle of the laser induced breakdown spectroscopy(LIBS) is interpreted.A LIBS experimental setup is developed based on Nd∶YAG laser and CCD grating spectrometer.Several experiments were carried out to study the effect of laser pulse energy,delay time and pressure.Atomic spectra was obtained using lower pulse energy;The best S/N could be realized by adjusting the delay time;Some samples could be induced to breakdown without strong continuum background;Emission signal with good S/N could be obtained at low pressure(5×10-5Pa),but the signal intensity was lower than at air pressure.The standard atomic spectra could be obtained by carrying out LIBS analysis of pure samples in the sample chamber,and the elemental recognition of unknown samples could be realized by comparing their atomic spectra with the standard spectra,in which the system recognition error was avoided.更多还原