前向散射和衍射对气溶胶消光特性测量的影响  

Effects of diffraction and forward scattering on aerosol extinction cross section measurement

作　　者：袁忠才[1] 林志丹[1] 赵大鹏[1] 

机构地区：[1]脉冲功率激光技术国家重点实验室,安徽省红外与低温等离子体重点实验室,电子工程学院,安徽合肥230037

出　　处：《激光与红外》2013年第1期34-37,共4页Laser & Infrared

基　　金：新世纪优秀人才支持计划(NCET);安徽省红外与低温等离子体重点实验室基金课题(No.2010A001005U)资助

摘　　要：气溶胶的消光特性通常利用所测得的透过率来计算得到。然而,在透过率测量中,粒子的前向散射和衍射光将到达探测器,增强了透射光,从而导致计算所得到的消光截面积等参数变小。本文引入束效率因子和有效消光截面来考察上述影响,得出的结果表明,粒子的散射相函数分布决定了误差的大小,为了减小前向散射和衍射带来的误差,气溶胶和探测器之间的距离应尽可能的大。The optical transmissivity is usually used to evaluate the properties of the aerosol. However,forward scatter ing and diffracting light by particles might reach the detector and would be incorrectly recorded, which would result in that the final optical density and experiment extinction cross section is erroneously low. The beam efficiency and effec tive extinction cross section are introduced to examine the error. The results indicate that the distance between the aerosol and the detector must be large enough in order to alleviate to error.

关 键 词：有效消光效率因子 束效率因子 前向散射 衍射 透过率 

分 类 号：TN958.98[电子电信—信号与信息处理]