不锈钢等离子体性能的激光诱导击穿光谱法研究

Study on plasma properties of stainless steel using laser induced breakdown spectroscopy

研究了由Nd:YAG激光的一级及二级谐波(SHG)产生的不锈钢等离子体参数的测量方法。根据已知的谱线进行光谱分析,利用Boltzmann法估算出了激发温度,而等离子体的电子密度是从谱线的Stark展宽剖面估算出来的。在常压下研究了等离子体的空间及时间演化过程,结果发现谱线的积分光强及积分宽度随着时间的延迟而降低。除了逆韧致辐射吸收的估算,同时研究了激光辐照度和波长对等离子体参数的影响。

The measurements of the stainless steel plasma parameters produced by the fundamental and second harmonic generation（SHG） of a Nd： YAG laser is reported. From the spectroscopic analysis of the observed spectral lines, the excitation temperature is estimated using Boltzmann plots,whereas the electron number density of the plasma is estimated from the Stark broadened profiles of the spectral lines. The spatial and temporal evolution of the plasma has been investigated at the atmospheric air pressure. It is found that both the integrated intensity and width of the spectral lines decreases with the time delay. The effect of laser irradiance and laser wavelength on the plasma parameters have also been studied in addition to estimation of the inverse bremstrahlung （IB） absorption.