L波段三维ESR成像系统的研制(Ⅰ)——L波段ESR成像的磁场及三维梯度磁场系统  

L-BAND THREE DIMENSIONAL ESR IMAGING SYSTEM (Ⅰ) --Magnet and Magnetic Gradients for L-band 3D-ESRI

作　　者：吴可[1] 丛建波[1] 先宏[1] 王长振[1] 孙存普[1] 郑莹光[2] 许静[2] 董凤霞[2] 沈尔中[2] 徐玉书[2] 宋涛[3] 黄常纲[3] 裴藏景[3] 

机构地区：[1]军事医学科学院放射医学研究所国家生物医学分析中心自由基与顺磁共振实验室,北京100850 [2]吉林大学分析测试中心,吉林长春130022 [3]中国科学院电工研究所,北京100080

出　　处：《波谱学杂志》2002年第4期337-343,共7页Chinese Journal of Magnetic Resonance

基　　金：国家自然科学基金资助项目 (2 993 5 0 80 )

摘　　要：研究并实现了L波段电子自旋共振三维成像 ( 3D EPRI)专用的三维梯度磁场系统 ,主磁场及扫描磁场系统以及相应的驱动控制系统 .梯度场线圈采用在铜板上用电切割方法加工的平板式线圈 ,避免了用铜导线绕制线圈体积较大的缺点 ,从而缩小了主磁场的体积和极间距 .梯度场强度在三维方向上均达到 2 0 0mT/m ,驱动电流为 2 0A .三维空间线性度均优于5 % ;线性区域大于直径 42mm的球形空间 .两磁极间距离为 63mm ,可以容纳通常体积的L波段谐振腔 .主磁场和扫描场线圈固定在同一轭铁架上 .它们可分别产生 1 .6～ 96mT和 0 .2～ 1 6mT的线性变化磁场 .5组磁场线圈 (包括主磁场 ,扫描磁场和三维梯度磁场 )分别由 5台独立的恒流驱动电源控制驱动 .电源通过数据接口由计算机控制 .初步成像实验证明本工作所建立的磁场和梯度磁场系统可以用于EPRI实验 .Main magnet, scan magnet and magnetic gradient coils used for L-band three dimensional electron paramagnetic resonance imaging were developed. Instead of using the conventional copper wire design to wind the gradient coils, they were built using a whole copper plate with the electrical line cut technique. The new design remarkably reduced the volume of the gradient coils, and made the main magnet more effective. The maximum gradient strengths in all three directions reached more than 200 mT/m with a driving current of 20 A. The spatial linearity of the gradients in all three directions was better than 5 %, and the linear range was larger than a sphere of 42 mm in diameter. The distance between the surfaces of the gradient coils was 63 mm, which was large enough to contain any type of L-band EPR cavity. The main magnet and the scan magnet coils were fixed on an iron frame. The magnet fields generated by the two magnets were 1.6～96 mT (main magnet) and 0.2～16 mT (scan magnet), respectively. All five magnet coils (main, scan and three gradients) were driven with five independent instant current power supplies, which were controlled by a computer through a data interface. The preliminary imaging test showed that the magnets are practical for 3D-EPRI applications.

关 键 词：电子自旋共振 ESR成像 磁场系统 三维梯度磁场 L波段 整体结构 性能指标 医学影像诊断 驱动控制系统 

分 类 号：O482.53[理学—固体物理] R445[理学—物理]