Current rise phenomena due to electron emission from CTJ in vacuum

摘要

In general, cathode triple junctions (CTJ) are regarded as electrical weakness points because of the occurrence of electron emission. It's believed that vacuum surface flashover starts from the initiation of electron emission at CTJ. Therefore, it is important to investigate electron emission phenomenon around the CTJ region. However, such a study which is direct measurement of the electron emission from CTJ has not been almost done because it is difficult to measure it directly. So, the purpose of this study is to elucidate the electron emission phenomenon from CTJ by investigating field electron emission current characteristics and charge distribution at CTJ region. Thus, we measured the electron emission current and the surface potential for the samples which CTJ was formed artificially. In addition, we simulated the electric lines of force near CTJ region. The results show that electron emission current increases due to the effect of the insulator surface being charged by the electrons emitted from the CTJ.