Some Characteritics of Si Target used for an Electron Microscopic Image Intensifier

Abstract

A Silicon diode array target has been studied for an electron microscope television system. The target is located inside of an electron microscope column and directly bombarded with imaging electrons. A current gain (ratio of bombarding current and signal current produced by electro bombardment in the target) of over 7, 000 is obtained when the target is bombarded with a high potential electron beam. Some characteristics of the target measured in the present experiment are as follows.(1) Current gain reaches to the maximum value at optimum beam potential and falls down in the higher potential region as well as in the lower region.(2) As the target thickness increases, the optimum value of beam potential shifts to the higher potential region. The maximum value of current gain also increases with thickness while the resolution decreases.(3) The resolution can be restored by elevation of the beam potential.After all, it becomes evident that the television system with the silicon-target provides a large brightness intensification in electron microscopic image obsevation and it is applicable for the wide range of beam potential (1001000kV) if the target is selected at the optimum thickness which depends on the applying beam potential.