タングステン ポイントフィラメントの電界放出模様の観察

Abstract

In order to study the electron optical properties of point-filament in the electron microscope gun, this experiment has been worked. By means of Muller type microscope, T-F emission patterns from tips of single crystal tungsten wire and ordinary one are observed in vacuum of 10^<-7>～10^<-8> Torr. The observed patterns show that the two kind of tungsten wires have little difference in lower temperature but large difference in higher temperature. It is shown that there exist differences between the emission patterns derived after the tips are heated up to the higher temperature and then cooled down to the room temperature applying the anode voltage throughout this process and the emission patterns derived after the tips are heated and then cooled without applying the anode voltage. It is concluded that the pattern's differences due to the high and room temperature of the tips are affected by the microscopic deformations of the tips by the electric field applied.