FIELD EMISSION APPARATUS AND HAND-HELD NONDESTRUCTIVE INSPECTION APPARATUS

摘要

In the present invention, heat dissipation is improved by extending the creeping distance in a vacuum vessel according to the size of a flange part, without lengthening the vacuum vessel in the direction in which an electron beam is emitted. A vacuum vessel (20) in which a flange portion (20a) having a hollow portion between a cold cathode (9) and an anode (11) is formed is used. One example is a vacuum vessel (20) in which a cold cathode vessel (21) and an anode vessel (22), both cylindrically shaped, are communicated with each other and a hollow flange portion (20a) is formed between the vessels (21, 22). A focusing electrode (14) and a getter material (15), for example, are disposed in the hollow portion of the flange portion (20a). A cold cathode (9) which has a guard electrode on the outer side of the periphery of a carbon film structure (10) formed on a substrate (7) may be used. The carbon film structure (10) may be formed in the middle of an electrode surface of the substrate (7).