摘要
为缓解中国西部地区淡水供需矛盾,研制了一种大功率核磁共振找水仪发射机。该发射机由DDS(Direct Digital Frequency Synthesis)芯片产生频率为当地拉莫尔频率的信号,通过大功率开关器件IGBT(Isolation Gate Bipolar Transistor)向天线等负载输出交变电流,从而激发地下水中氢质子产生可供检测的核磁信号,已成功应用到地面核磁共振找水仪样机中。与目前世界上唯一商品化的法国NUMIS(Nuclear Magnetic Induction System)系统相比,其频率范围(1~4 kHz)比NUMIS(0.8~3 kHz)宽,最大脉冲矩(18000 A.ms)比NUMIS(9000 A.ms)大,能够应用于更深层地下水的探测。
For alleviating the supply conflict of fresh water at western region, a kind of strong-power nuclear magnetic resonance transmitter for detecting water is devdeleped. Producing local larmor frequency by the DDS (Direct Digital Frequency Synthesis) chip and outputting alternating current via big power switch device-IGBT ( Isolation Gate Bipolar Transistor) to load such as antenna and capacitance. Accordingly, it excitateds hydro- gen proton to produce nuclear magnetic signal. The transmitter successfully apply into the SNMR (Surface Nu- clear Magnetic Resonance) prototype. Compared to the only commercial NUMIS (Nuclear Magnetic Induction System) in the world, the maximal excitation pulse moment of the transmitter can exceeds to 18 000 A ~ ms, while the transmitter of the NUMIS system is only 9 000 A ~ ms, so the transmitter can be applied to the detection of deeper underground water.
出处
《吉林大学学报(信息科学版)》
CAS
2007年第3期268-272,共5页
Journal of Jilin University(Information Science Edition)
基金
国家863计划基金资助项目(2002AA784030)
关键词
核磁共振
直接数字频率合成器
绝缘栅极双极型晶体管
谐振
nuclear magnetic resonance
direct digital frequency synthesis (DDS)
isolation gate bipolar transistor (IGBT)
resonance
作者简介
姜艳秋(1981-),女,黑龙江富锦人,吉林大学硕士研究生,主要从事功率电子技术应用研究.(Tel)86-13843028309(E-mail)qiuqiu528@tom.com.
王应吉(1956-),男,山西孝义人,吉林大学副教授,主要从事电磁法地学仪器研究,(Tel)86-431-88502474(E-mail)wangyj@jlu.edu.cn.