【摘 要】
：
本文所设计的核磁共振传感器具有不同工作频率的梯度磁场探测模式和均匀静磁场探测模式,同时又兼具了便携性与室内中型仪器的精确性.该传感器既能够实现便携探测又能够在多频率和不同磁场探测模式下对样品进行精确探测,既能够得到样品内局部切片在不同频率下的核磁共振响应又能够得到整体样品的核磁共振响应.经设计和模拟仿真,本文所设计的传感器具有三种工作模式.模式一为便携模式,采用单一磁体组件,重量和体积均较小,具有
【机 构】
：
油气资源与探测国家重点实验室,中国石油大学(北京)102249
【出 处】
：
第八届全国低场核磁共振技术与应用研讨会
论文部分内容阅读
本文所设计的核磁共振传感器具有不同工作频率的梯度磁场探测模式和均匀静磁场探测模式,同时又兼具了便携性与室内中型仪器的精确性.该传感器既能够实现便携探测又能够在多频率和不同磁场探测模式下对样品进行精确探测,既能够得到样品内局部切片在不同频率下的核磁共振响应又能够得到整体样品的核磁共振响应.经设计和模拟仿真,本文所设计的传感器具有三种工作模式.模式一为便携模式,采用单一磁体组件,重量和体积均较小,具有较高的便携性.模式二采用模式一磁体与外环磁体组件组合,模式三采用外环磁体组件与另一内环组件组合,二者都为组合模式,具有较高的探测精确度.模式一与二为梯度磁场探测模式,所产生的静磁场均为在其各自的目标区域内水平方向上分布近似均匀.模式一的目标区域为磁体表面3.75cm处3*3*3cm3范围内,在该区域中心处1cm范围内,磁场均匀度约为185.9ppm,梯度约为3.25T/m.模式二的目标区域为磁体表面5cm左右处5*5*5cm3范围内,在该区域中心处2cm范围内,磁场均匀度约为97.9ppm,梯度约为3.91T/m,该模式较模式一具有更高的工作频率,体积更大的敏感区域,更高的信噪比,和更精确的探测精度.模式三为均匀磁场探测模式,磁体所产生的静磁场在磁体表面约为2.7cm处一X型空间区域内产生近似均匀分布.由各工作模式对应静磁场可得出与之对应的射频场,采用等效电流密度的方法可进行射频天线的设计.
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