| 摘要 |
A cryogenic adsorption pump comprises a suction element with a reservoir (4) for the cryo-agent of a lower temperature, a radiation screen embracing the suction element, a tube (25) and a thermal bridge (24). The radiation screen comprises a reservoir (15) for the cryo-agent of a higher temperature, an envelope (16) connected by its upper end to said reservoir (15) and by its lower end to the reservoir (4) of the suction element. The tube (25) passes through a gap between the internal walls of the reservoirs (4 and 15) and is connected by its lower end to the bottom (28) of a casing (1) and by its upper end to the reservoir (4) of the suction element. During the functioning of the pump a protective vacuum chamber (31) is created in the gap between the radiation screen and the casing, whereas a protective vacuum chamber (36) is created in the space situated between the radiation screen, the tube (25), the reservoir (4) of the suction element and the thermal bridge (24). These chambers (31 and 36) prevent heat exchange by the suction gases at pressures exceeding 10<-2>Pa, respectively, between the casing (1) and the radiation screen and between the first and the last suction elements. |
