磁镜阵列像增强器的调制传递函数研究

基于三代近贴式像增强器,设计了磁镜阵列装置的结构,从理论上计算了该装置的调制传递函数以及将其引入像增强器后整体的调制传递函数,以此来分析对成像质量的影响.通过对实际参量绘制的调制传递函数曲线分析,得出磁镜阵列装置在X、Y方向的极限分辨率分别为117 lp/mm、121 lp/mm,奈奎斯特频率处的调制传递函数值分别为0.55、0.59,同时磁镜阵列像增强器的极限分辨率也分别达到了87 lp/mm、89 lp/mm,相应的奈奎斯特频率处的调制传递函数值为0.49和0.52.结果表明X和Y方向的调制传递函数曲线之间差异较之磁镜阵列装置变小,这对保证成像质量起到了积极的作用.文章为进一步深入研究磁镜阵列像增强器提供了重要的理论依据.

MTF of Magnetic Mirror Array Image Intensifier

The structure of the magnetic mirror array device is designed.The modulation transfer function (MTF) of this device is calculated as well as that of magnetic mirror array image intensifier.The limiting resolutions of 117 lp/mm and 121 lp/mm of the magnetic mirror array device,by means of the analysis of MTF curves with the actual parameters,are obtained at X and Y directions in which the Nyquist frequencys are 0.55 and 0.59 respectively|while the limiting resolutions of magnetic mirror array image intensifier based on this device are 87 lp/mm and 89 lp/mm,and the corresponding Nyquist frequencys are 0.49 and 0.52 respectively.The results show that the difference between two curves at X and Y directions can be reduced to ensure better image quality.The calculation of this research provides an important theoretical basis for further research on the magnetic mirror array image intensifier.