光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2014年
12期
3397-3400
,共4页
激光诱导击穿光谱%煤成分%微量元素%自吸收
激光誘導擊穿光譜%煤成分%微量元素%自吸收
격광유도격천광보%매성분%미량원소%자흡수
Laser induced breakdown spectrum%Coal%Trace element%Self-absorption
以脉冲Nd∶AG激光器的二倍频输出为激发源,获得了一种家庭用煤的激光诱导击穿光谱(laser induced breakdown spectrum ,LIBS)。通过对谱线的归属,发现该煤种除包含文献报道的C ,Si ,Mg ,Fe , Al ,Ca ,Ti ,Na ,K元素外,还包含Cd ,Co ,Hf ,Ir ,Li ,Mn ,Ni ,Rb ,Sr ,V ,W ,Zn ,Zr等微量元素,谱图中没有出现对应H和O元素的谱线,把该现象归因于H和O原子的跃迁概率较小,而灵敏谱线对应跃迁的上能级能量较大。同时发现随激光脉冲能量的增加,等离子体发射谱线的强度增大,增加到一定程度,K原子766.493和769.921 nm谱线会出现自吸收现象,自吸收的程度随激光能量的增加而增强,出现明显的双峰结构,把自吸收现象归因于原子大的跃迁概率及激光强度增加引起等离子体中粒子数密度的增大。
以脈遲Nd∶AG激光器的二倍頻輸齣為激髮源,穫得瞭一種傢庭用煤的激光誘導擊穿光譜(laser induced breakdown spectrum ,LIBS)。通過對譜線的歸屬,髮現該煤種除包含文獻報道的C ,Si ,Mg ,Fe , Al ,Ca ,Ti ,Na ,K元素外,還包含Cd ,Co ,Hf ,Ir ,Li ,Mn ,Ni ,Rb ,Sr ,V ,W ,Zn ,Zr等微量元素,譜圖中沒有齣現對應H和O元素的譜線,把該現象歸因于H和O原子的躍遷概率較小,而靈敏譜線對應躍遷的上能級能量較大。同時髮現隨激光脈遲能量的增加,等離子體髮射譜線的彊度增大,增加到一定程度,K原子766.493和769.921 nm譜線會齣現自吸收現象,自吸收的程度隨激光能量的增加而增彊,齣現明顯的雙峰結構,把自吸收現象歸因于原子大的躍遷概率及激光彊度增加引起等離子體中粒子數密度的增大。
이맥충Nd∶AG격광기적이배빈수출위격발원,획득료일충가정용매적격광유도격천광보(laser induced breakdown spectrum ,LIBS)。통과대보선적귀속,발현해매충제포함문헌보도적C ,Si ,Mg ,Fe , Al ,Ca ,Ti ,Na ,K원소외,환포함Cd ,Co ,Hf ,Ir ,Li ,Mn ,Ni ,Rb ,Sr ,V ,W ,Zn ,Zr등미량원소,보도중몰유출현대응H화O원소적보선,파해현상귀인우H화O원자적약천개솔교소,이령민보선대응약천적상능급능량교대。동시발현수격광맥충능량적증가,등리자체발사보선적강도증대,증가도일정정도,K원자766.493화769.921 nm보선회출현자흡수현상,자흡수적정도수격광능량적증가이증강,출현명현적쌍봉결구,파자흡수현상귀인우원자대적약천개솔급격광강도증가인기등리자체중입자수밀도적증대。
The LIBS of one kind of household fuel coal was obtained with the first harmonic output 532 nm of an Nd?YAG laser as radiation source .With the assignment of the spectral lines ,it was found that besides the elements C ,Si ,Mg ,Fe ,Al ,Ca , Ti ,Na and K ,which are reported to be contained in coal ,the presented sample also contains trace elements ,such as Cd ,Co , Hf ,Ir ,Li ,Mn ,Ni ,Rb ,Sr ,V ,W ,Zn ,Zr etc ,but the spectral lines corresponding to O and H elements did not appear in the spectra .This is owing to the facts that the transition probability of H and O atoms is small and the energy of the upper level for transition is higher .The results of measurement also show that the intensity of spectral line increases with the laser pulse energy and self-absorption of the spectral lines K766.493 nm and K769.921 nm will appear to some extent .Increasing laser energy fur-ther will make self-absorption more obvious .The presence of self-absorption can be attributed to two factors .One is the higher transition rate of K atoms ,and the other is that the increase in laser intensity induces the enhancement of the particle number density in the plasma .