L波段三维ESR成像系统的研制(Ⅴ)——灵敏度与分辨率实验及系统总性能指标

DEVELOPMENT OF L BAND THREE DIMENSIONAL ESR IMAGING SYSTEM(Ⅴ)——System Configuration and Performance Evaluation

实验确定了自行研制的L波段三维电子自旋共振成像 ( 3D ESRI)系统的检测灵敏度及成像分辨率指标 .用Tempo水溶液模型测量灵敏度结果表明 :样品体积为1 0mm ,高 30mm ,测量浓度 1× 1 0 - 4 mol/L水溶液的信噪比为S/N =4∶1 ;加梯度磁场后 ,样品浓度需 >5× 1 0 - 4mol/L ,样品体积为1 9mm ,高 30mm时 ,获得的投影谱的信噪比可满足图像重建的需要 .用DPPH固体样品确定的成像分辨率结果 <1mm .文中还对ESRI系统的各项总体性能做了归纳总结 .

The detection sensitivity and the achievable spatial resolution of a newly developed L-band three-dimensional ESR imaging system were evaluated. The detection sensitivity was measured using a group of samples of aqueous Tempo solution. A signal to noise ratio (S/N) of about 4∶1 was obtained on a cylindrical sample with diameter of 10 mm and height of 30 mm, which corresponds to the minimum detectable concentration of 1×10^(-4)mol/L. To obtain projections with sufficient S/N for imaging, a higher concentration of more than 5×10^(-4)mol/L and a larger sample size (diameter of 19 mm and height of 30 mm) was needed. Measured on solid DPPH samples, the spatial resolution of imaging can reach about 1 mm. The general performance features of the ESRI system were also discussed in the paper.