湿度对激光诱导土壤等离子体特性的影响  

Influence of Humidity on Characteristic of Laser-Induced Soil Plasmas

作　　者：鲁翠萍 刘文清[1] 赵南京 刘立拓 陈东[1] 张玉钧[1] 刘建国[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所,中国科学院环境光学与技术重点实验室,安徽省环境光学监测技术重点实验室,安徽合肥230031

出　　处：《光谱学与光谱分析》2010年第11期2885-2888,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(60908018);中国科学院知识知识创新工程重大项目(kzcx1-yw-06-01);安徽省科技计划项目(083H3b1581);所长基金课题(073H371141)资助

摘　　要：为研究土壤湿度对激光等离子体的影响,通过制备六种不同湿度的土壤样品进行实验,选取铅的特征谱线(Pb:405.78nm)为分析线。实验结果表明,随着土壤湿度的增加,谱线的强度、信噪比及RSD线性减小。在局部热力学平衡近似下,选取铁在400～440nm波长范围内的四条特征谱线,利用玻尔兹曼图,测定了等离子体温度在不同湿度下的变化特性,随着湿度从零增加到20%,等离子体温度从11800K近似单调的下降到7800K,电子密度从3.3×106cm-3减小到2.8×106cm-3。The soil samples at six different humidities were prepared for studying the influence of soil humidity on laser-induced plasmas.By analyzing the characteristic spectral lines of Pb with the wavelength of 405.78nm,it was demonstrated that the intensities of spectral line,SNR and RSD are linearly inversely proportional to the soil humidity.Under the approximation of local thermal equilibrium,by analyzing the characteristic spectral lines of Fe within the wavelength range of 400 to 440nm,the temperature of plasmas was obtained by means of the two-dimensional Boltzmann plane.The experimental results show that the plasma temperature monotonously changes from 11 800 to 7 800K and the electron density monotonously changes from 3.3×106 cm-3 to 2.8×106 cm-3,when the humidity increases from 0 to 20%.

关 键 词：激光诱导击穿光谱 激光等离子体 土壤湿度 等离子体温度 电子密度 

分 类 号：O657.3[理学—分析化学]