光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2014年
6期
1524-1527
,共4页
痕量甲烷气体%量子级联激光器%herriott气室%地震前兆预警
痕量甲烷氣體%量子級聯激光器%herriott氣室%地震前兆預警
흔량갑완기체%양자급련격광기%herriott기실%지진전조예경
Trace methane gas%Quantum cascade laser%Herriott cell%Earthquake pre-alarming
随着地震断裂带气体观测技术的快速发展,为了对地震进行精确的预报,减少因地震给人民群众生命和财产带来的损失,根据甲烷气体的释放与地震前上地壳岩石的微裂隙有直接关系的这一微观变化,设计并研制中红外痕量甲烷气体检测仪。仪器采用激发波长为7.65μm 的量子级联激光器(QCL),结合双光路长度为76 m的多次反射herriott长光程气体吸收池,可以在4 s 的采样时间内实现40 nmol·mol-1气体检测灵敏度。同时,采用半导体激光器频率调制直接光谱吸收技术,降低了该仪器噪声的主要来源1/f噪声,使气体检测下限达到5 nmol·mol-1(40 s采用时间)。在野外实验中,利用可控震源车作为模拟地震源,将6个痕量甲烷检测仪以100 m为距离等间隔放置,对距震源中心不同距离下的地表面甲烷气体浓度进行动态测量。实验表明,该仪器可以监测地震前地下痕量甲烷气体的释放,为地震前兆预警提供新的途径。
隨著地震斷裂帶氣體觀測技術的快速髮展,為瞭對地震進行精確的預報,減少因地震給人民群衆生命和財產帶來的損失,根據甲烷氣體的釋放與地震前上地殼巖石的微裂隙有直接關繫的這一微觀變化,設計併研製中紅外痕量甲烷氣體檢測儀。儀器採用激髮波長為7.65μm 的量子級聯激光器(QCL),結閤雙光路長度為76 m的多次反射herriott長光程氣體吸收池,可以在4 s 的採樣時間內實現40 nmol·mol-1氣體檢測靈敏度。同時,採用半導體激光器頻率調製直接光譜吸收技術,降低瞭該儀器譟聲的主要來源1/f譟聲,使氣體檢測下限達到5 nmol·mol-1(40 s採用時間)。在野外實驗中,利用可控震源車作為模擬地震源,將6箇痕量甲烷檢測儀以100 m為距離等間隔放置,對距震源中心不同距離下的地錶麵甲烷氣體濃度進行動態測量。實驗錶明,該儀器可以鑑測地震前地下痕量甲烷氣體的釋放,為地震前兆預警提供新的途徑。
수착지진단렬대기체관측기술적쾌속발전,위료대지진진행정학적예보,감소인지진급인민군음생명화재산대래적손실,근거갑완기체적석방여지진전상지각암석적미렬극유직접관계적저일미관변화,설계병연제중홍외흔량갑완기체검측의。의기채용격발파장위7.65μm 적양자급련격광기(QCL),결합쌍광로장도위76 m적다차반사herriott장광정기체흡수지,가이재4 s 적채양시간내실현40 nmol·mol-1기체검측령민도。동시,채용반도체격광기빈솔조제직접광보흡수기술,강저료해의기조성적주요래원1/f조성,사기체검측하한체도5 nmol·mol-1(40 s채용시간)。재야외실험중,이용가공진원차작위모의지진원,장6개흔량갑완검측의이100 m위거리등간격방치,대거진원중심불동거리하적지표면갑완기체농도진행동태측량。실험표명,해의기가이감측지진전지하흔량갑완기체적석방,위지진전조예경제공신적도경。
With the rapid development of gas observation technology in seismic fracture zone,in order to accurately predict the earthquake,and reduce the people’s lives and property losses caused by earthquake,a mid-infrared methane sensor was designed and developed,which is based on the microscopic relation between methane release and earthquake fissures on the crustal rocks. This instrument utilizes quantum cascaded laser (QCL)operating at 7. 65μm,combined with MIR multipass herriott cell with 76 m absorption path length to obtain low detection sensitivity down to 40 nmol·mol-1 level in 4s acquisition time.Meanwhile, to decrease the primary noise source (1/f noise),semiconductor laser frequency modulation of direct absorption technology was utilized to obtain gas detection limitation as low as 5 nmol·mol-1 (40 s acquiring time).In field experiments,controllable vibra-tor was used as vibration source,a number of trace methane detectors were placed with 100 m distance interval to carry out the dynamic measurement of methane concentration on the ground surface at different distances from the vibration source.Experi-mental results show that the instrument can monitor the release of underground methane before the earthquake and provide a no-vel measure as a pre-alarming for earthquake.