As the core component of image intensifier, the electronic multiplication performance of microchannel plate determines the ability of the device to detect weak signals. The theoretical model of electron gain is the theoretical basis for the secondary electron multiplication of microchannel plates. It has important theoretical significance for the research of high performance microchannel plates and image intensifiers. In this paper, the theoretical model and simulation of electron gain in microchannel plates are reviewed. The electronic gain model and the modified theoretical model of the "energy proportional hypothesis" are emphatically introduced. On the basis of the model, some improvements are made and good simulation results are obtained. The behaviors of electron transport, collision and multiplication in microchannels based on the theoretical model of electronic gain and Monte Carlo stochastic calculation method are summarized. The differences among the three models are analyzed, and the problems existing in the theoretical model and simulation of electronic gain at present are analyzed. Finally, aiming at the shortcomings of theoretical model and simulation, the direction of improvement and optimization is put forward.
As a two dimensional arrays of micro-channel X-ray imaging precision optics, detection efficiency and imaging quality are crucial to micro-channel optics (MPO). As a key factor of the detection efficiency and imaging quality, cell packed geometries in the Wolter type micro-channel optics were investigated in the paper. The characteristics of simulative images for different cell packed geometries were compared with the software Tracepro by ray trace method of Monte Carlo algorithm. The influences for the amount of symmetry axes, chamber types and stacked density of layers on the focal imaging characteristics and detection efficiency of Wolter type micro-channel optics were explored. The results indicated that the detection efficiency and the quality of focal imaging changing both obeyed Parabola distribution with the increasing of the numbers of symmetry axis from three to six. In the cambered stacking models, focusing images showed a petaline shape dispersion background with the same symmetry axis in non-full-cambered stacking types. In the close-packed loss model, it had a minimal and maximal impact on the detection efficiency in the outmost layer and subouter layer, respectively. Besides, characteristics of simulative images for Lobster eye micro-channel optics (L-MPO) and Wolter type micro-channel optics (W-MPO) were compared by ray trace method in this paper. Results indicated that under a constant illumination with the same cell size, the simulated detection efficiency of ideal W-MPO was over 41.0%, which was 1.3 times than that of ideal L-MPO.
Micro-channel optics (MPO) is a two dimensional arrays of capillary channel EUV/X-ray imaging precision optics. Imaging quality and detection efficiency are crucial to EUV/X-ray detection. Radial packed square-pore type micro-channel optics (RPMPO) is a novel MPO, which is preferable to the cruciform focus of Square packed square-pore micro-channel optics (SPMPO, namely Lobster eye optics) geometry. Cell defects of micro-channel affect the imaging quality and detection efficiency seriously, however, which were inevitable in the MPO manufacturing. In this paper, characteristics of focusing images for standard and defect states RPMPOs were compared by ray trace method of Monte Carlo algorithm. Three main cell defects, such as Taper, Twist and Nonsquare, were investigated in the influence on the imaging quality and detection efficiency under different cell flaw sizes. Results indicated that under a constant illumination, Nonsquare defects of cell affected the detection efficiency most, twist defects did less, and taper defects did least. Besides, twist defects of cell affected the quality of focal image most, nonsquare defects did less, and taper defects did least. The detection efficiency decreasing obeyed the Boltzmann, Bidoseresp and Lorentz function as the increasing of conical degree, twist angle and fillet radius in taper, twist and nonsquare defect, respectively. The focal imaging quality deteriorating obeyed Expdec1, Expdec3 and Langevin distribution with the increasing of conical degree, twist angle and fillet radius in taper, twist and nonsquare defect, respectively.This results supplied a significant support for the future researches on curved MPO and EUV/X-ray optical system based on MPO.