| 摘要 |
PURPOSE:To increase the strength of the title film and to prevent the damage of said film by radiations, etc., by expending at least two sheets of beryllium films in tight contact with each other. CONSTITUTION:The beryllium film 1 is provided on an inner side of an O-ring 3 and shuts off the heat rays, charged particles, impact waves, and splashes generated by an electric discharge to prevent the damage of the beryllium film 2 which makes vacuum sealing. The thickness of the beryllium film 1 is specified to about 5mum and the thickness of the beryllium film 2 to about 15mum. The beryllium film 2 is held pressed upward by the atm. and since the wind pressure that the beryllium film 1 receives from the impact waves is directed downward, said film is supported by the beryllium film 2. The heat that the beryllium film 1 receives is transmitted by the heat conduction from the contact part to the beryllium film 2 which is cooled by the atm. The strength of the film is thereby increased and the damage by the heat rays, charged particles, etc., is substantially prevented. |
