Cryopump and method of starting the cryopump
First Claim
1. A method of starting a cryopump comprising:
- providing a first stage cryopanel and a second stage cryopanel in a pumping volume, providing a close cycle refrigerator having a first stage and a second, colder stage in an insulating volume, and thermally isolating the refrigerator from the cryopanels and from the pumping volume by means of a vacuum in the insulating volume;
operating the refrigerator to cool it to cryopumping temperatures;
thereafter providing a thermal coupling between the refrigerator first stage and the first stage cryopanel to cool the first stage cryopanel and thereby condense gases thereon from the pumping volume; and
thereafter providing a thermal coupling between the refrigerator second stage and the second stage cryopanel to cool the second stage cryopanel and thereby condense additional gases thereon from the pumping volume.
2 Assignments
0 Petitions
Accused Products
Abstract
The refrigerator of a cryopump is positioned within an insulating vacuum and the two stages of the refrigerator are selectively thermally coupled to first and second stage cryopanels. After initial rough pumping by an air ejector, rough pumping is completed during startup by coupling the cold first stage of the refrigerator to a first stage adsorption cryopanel. The second stage of the refrigerator is thereafter coupled to the second stage cryopanel. Thermal coupling of the refrigerator to the cryopanels is by means of spring biased thermal contacts brought into position by movement of the refrigerator. The thermal contact elements are provided with sufficiently large thermal masses to handle the large thermal loads of system startup.
82 Citations
27 Claims
-
1. A method of starting a cryopump comprising:
-
providing a first stage cryopanel and a second stage cryopanel in a pumping volume, providing a close cycle refrigerator having a first stage and a second, colder stage in an insulating volume, and thermally isolating the refrigerator from the cryopanels and from the pumping volume by means of a vacuum in the insulating volume; operating the refrigerator to cool it to cryopumping temperatures; thereafter providing a thermal coupling between the refrigerator first stage and the first stage cryopanel to cool the first stage cryopanel and thereby condense gases thereon from the pumping volume; and thereafter providing a thermal coupling between the refrigerator second stage and the second stage cryopanel to cool the second stage cryopanel and thereby condense additional gases thereon from the pumping volume. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A cryopump comprising:
-
a first stage cryopanel and second stage cryopanel in a pumping volume; a refrigerator having a first stage and a second, colder stage in an insulating volume, the insulating volume having a vacuum therein to thermally isolate the refrigerator from the first and second stage cryopanels and from the pumping volume; and means for first thermally coupling the refrigerator first stage to the first stage cryopanel and thereafter coupling the refrigerator second stage to the second stage cryopanel. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. A cryopump comprising:
-
a first stage cryopanel and second stage cryopanel in a pumping volume; a refrigerator having a first stage and a second, colder stage in an insulating volume, the insulating volume having a vacuum therein to thermally isolate the refrigerator from the first and second stage cryopanels and from the pumping volume; and means for moving the refrigerator relative to the first and second stage cryopanels to bring the refrigerator within the insulating volume into and out of thermal contact with the cryopanels.
-
-
27. A cryopump comprising a first stage adsorption cryopanel and a second stage cryopanel in a pumping volume;
-
an ejector for rough pumping the pumping volume; a refrigerator having a first stage and a second, colder stage in an insulating volume, the insulating volume having a vacuum therein to thermally isolate the refrigerator from the first and second stage cryopanels and from the pumping volume; a high thermal mass contact element in thermal contact with and spring biased relative to the first stage of the refrigerator; and means for moving the refrigerator within the vacuum vessel such that the first and second stages of the refrigerator can be moved into thermal contact with the first and second stage cryopanels with the first stage being coupled prior to the second stag being coupled.
-
Specification