微通道板像增强器的调制传递函数的测量与研究

根据狭缝法测量调制传递函数（MTF）的理论,建立了微通道板（MCP）像增强器的MTF测量装置.利用CCD相机测量像增强器对狭缝的空间响应,得到系统的线扩散函数(LSF),经过傅里叶变换求出MTF.实验测量了两种MCP像增强器的MTF,得到的极限分辨率与厂家标定值一致.在不同的工作偏压下以及不同的像面位置处的MTF测量结果表明,像增强器的空间分辨能力随着光阴极偏压的升高逐渐提高并趋于稳定.随MCP偏压的升高而迅速下降,在一定的电压范围内不随荧光屏电压的变化而改变；像增强器在不同像面位置处的空间分辨能力变化较小.

MTF Measurement and analysis of Micro-channel Plate Image Intensifiers

A measurement system was established to calculate the Modulation Transfer Function (MTF) of micro-channel plate image intensifiers (MCPIIs). When a narrow slit was projected onto the photocathode of MCPII as an input, line spread function (LSF) was found by recording a digital image of MCPIIs′ output with a CCD camera. The Fourier transform of LSF yielded MTF. Two Gen-II MCPIIs were measured under different bias and different input position. The MTF results are in agreement with the limiting resolution given by manufacturers. With the increase of MCPIIs′ PC bias, the resolution is improved rapidly before 140 V and then goes steady. Both MCPIIs suffer a rapid reduction in resolution at high MCP bias voltages. The phosphor voltage and input position have little influence on the resolution.