摘要 |
PURPOSE:To effectively perform cathode aging by setting the cathode temperature in the flashing process to a temperature exceeding a specified temperature. CONSTITUTION:By the even balance between the evaporation of Ba at high temperatures and a damage such as the deterioration of dielectric strength characteristics resulting from the evaporation, the time when a high temperature exceeding 1,350 deg.K is kept is set to 2 to 5min and the flashing temperature is allowed to exceed 1,350 deg.K or desirably is set to 1,400 deg.K. As a result, good cathode activation is obtained and good emission can be maintained during life and stable characteristics can be obtained for a long period of time. |