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介绍了一种新型的inside-out核磁共振传感器。该传感器磁体结构由三个沿轴向磁化的圆柱形永磁体同轴排列而成,结构紧凑。通过调节三个磁体之间的距离,可以在磁体结构外侧建立起径向对称的均匀静态磁场或有恒定梯度的静态磁场B_0,其方向平行于传感器轴向。为了满足射频磁场B_1垂直于静态磁场B_0的要求,射频线圈采用马鞍形结构。传感器直径为2.8cm,长度为6cm,重为200g。该传感器磁体结构简单,且灵敏区域相对其本身尺寸较大。
A new type of inside-out NMR sensor is introduced. The sensor magnet structure is composed of three coaxial cylindrical permanent magnets magnetized in the axial direction and is compact in structure. By adjusting the distance between the three magnets, a radially symmetrical uniform static magnetic field or a constant gradient static magnetic field B_0 can be established outside the magnet structure in a direction parallel to the sensor axis. In order to meet the requirement that the RF magnetic field B_1 is perpendicular to the static magnetic field B_0, the RF coil adopts a saddle-shaped structure. The sensor has a diameter of 2.8 cm, a length of 6 cm and a weight of 200 g. The sensor magnet has a simple structure and the sensitive area is relatively large in size.