研究了水分对激光诱导击穿煤粉等离子体特性的影响,以分析水分对激光诱导击穿煤粉定量测量的影响。实验选取了空干基C和Si元素含量相近但水分差别较大的神华煤和平朔煤,分别采用其收到基和干燥基共4个样品进行实验。采用Ca的原子谱线计算了各样品在延迟时间分别为83ns,500ns,917ns和1292ns时的激光诱导击穿等离子体温度,并分别用C247.856nm和Si390.5523nm特征谱线估算了电子密度。实验表明,各样品的激光等离子体温度随着延迟时间的增大而降低,含水分的煤样其激光诱导击穿等离子体的温度较低,而电子密度受水分的影响不大,含水分的煤样其激光诱导击穿的特征谱线强度较弱。
The impact of the moisture on character of laser induced pulverized coal plasma was conducted to determine the influence of moisture on quantitative measurement of coal by laser-induced breakdown spectroscopy. Two samples (Shenhua coal and Pingshuo coal) with close carbon and silicon contents but different water contents were chosen and prepared as received basis and dry basis individually. Calcium atomic spectra lines were used to calculate the plasma temperature at delay time of 83 ns, 500 ns, 917 ns and 1292 ns. C247. 856 nm and Si390. 5523 nm were chosen to estimate electron density. The results show that the plasma temperature declines as the delay time is prolonged, lower plasma temperature and poorer spectra lines intensity are presented in the samples with moisture, but electron density does not change significantly with different samples.