大定源瞬变电磁法矩形发射回线激发的电磁场  

ELECTROMAGNETIC FIELD TRANSMITTED BY RECTANGULAR LOOP IN LARGE FIXED TEM

作　　者：李建慧[1] 刘树才[1] 李富[1] 赵贤任[1] 刘仰光[1] 

机构地区：[1]中国矿业大学资源学院,徐州221008

出　　处：《物探化探计算技术》2008年第2期154-157,共4页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家重点基础研究发展计划(973)项目资助(2007CB209406)

摘　　要：首先从垂直磁偶极子产生的电磁场表达式出发,推导出了矩形发射回线产生的电磁场表达式;然后通过Guptasarma积分和Hankel积分将这些表达式转换为时间域电磁场,求出感应电动势;最后通过模型计算来难验证其正确性。通过数值模拟发现,在层状介质模型情况下,矩形发射回线中心区域电磁场的瞬变响应近乎均匀,地表低阻层对电磁场有很强的屏蔽作用。Based upon the electromagnetic expressions induced by vertical magnetic dipole, this paper has deduced electromagnetic expressions induced by rectangular transmitting loop. Then these expressions are converted into time domain by Guptasarma integral and Hankel integral. At last, by setting models and calculating induced emf, the validity of the deduced theory is verified. By numerical simulation, it is found that central region of loop's electromagnetic field can be regarded as uniform electromagnetic field approximately under homogeneous layered media condition; and prove that a low resistivity layer could shield electromagnetic field in shallow ground.

关 键 词：大定源瞬变电磁法 矩形回线 Guptasarma积分 感应电动势 

分 类 号：P631.325[天文地球—地质矿产勘探]