| 摘要 |
PROBLEM TO BE SOLVED: To shorten the cooling time of a cryopump.SOLUTION: A cryopump 10 is equipped with a cryopanel, and a refrigerator 16 for cooling the cryopanel. The refrigerator 16 is equipped with a refrigerator motor 80 for driving the refrigerator 16, and a refrigerator inverter 82 for controlling the operation frequency of the refrigerator motor 80. A control portion 100 of the cryopump 10 controls the refrigerator 16 so as to execute cool-down operation lowering the temperature of the cryopanel from room temperature to referent operation temperature. The control portion 100 is equipped with an operation frequency deciding portion 110 which decides the operation frequency of the refrigerator motor 80 within an operation frequency range having an operation frequency upper limit, and outputs the operation frequency to the refrigerator inverter 82; and an upper limit adjusting portion 112 which lowers an operation frequency upper limit on the basis of the temperature drop of the cryopanel during the cool-down operation.SELECTED DRAWING: Figure 2 |
