Fabrication of the hohlraum gas-filled target connected with gas source

Filling gas on the spot is widely used to fabricate the hohlraum gas-filled target. This paper focuses on the synthesis of the polypyromellitamic acid, preparation of polyimide film by the method of spin coating and gas-filled targets assemblage. Two key issues here are the preparation of synthetic polypyromellitamic acid and the examination of leakage in vacuum. The gas pressure can be read by transducer connected with the target through the gas tube. Under suitable condition the polyimide film can be made with thickness of 0.2~1.0 μm. The film finish is about 0.3~0.4 nm and the pressure error inside the target is less than 0.1%.