PURPOSE: To speed up the pumping sped by surrounding the system, which consists of a cryopanel, a superfilter, and a trap chamber, with a Chevron chamber that is cooled to a specified temperature.
CONSTITUTION: The first Chevron chamber 11, which is situated outside and which is cooled down to about 100°K, and the second Chevron chamber 12, which is situated inside with respect to the first Chevron chamber 11, are arranged to the inside of a pump case 20. The second Chevron chamber 12 is cooled down to about 4.2°K by means of liquid helium. In the inside of the second Chevron chamber 12. A cryopanel 13 is connected to a trap chamber 14 by means of a superfilter 15 made up of many, minute flow passages. Since the cryopanel 13 and the trap chamber 14 are surrounded by doubled Chevron chamber, the pumping sped of the cryopanel 13 per unit area can be increased.
YUYAMA JUNPEI
YAMAKAWA HIROYUKI
