Method and apparatus for throttling gas flow to a cryopump
First Claim
Patent Images
1. A cryopump comprising a cold first stage and a colder second stage, a second stage cryopanel, a radiation shield surrounding the second stage and a first stage orifice plate closing the radiation shield, the orifice plate having a plurality or orifices therein for allowing restricted flow of gas into the radiation shield to the second stage cryopanel, at least one of the orifices being closed by a removable closure secured to the orifice plate at the closed orifice.
1 Assignment
0 Petitions
Accused Products
Abstract
Orifices in a cooled plate throttle gases entering a cryopump. Selected orifices are closed by removable closures such as spring clips to allow the throttling to be varied.
19 Citations
7 Claims
- 1. A cryopump comprising a cold first stage and a colder second stage, a second stage cryopanel, a radiation shield surrounding the second stage and a first stage orifice plate closing the radiation shield, the orifice plate having a plurality or orifices therein for allowing restricted flow of gas into the radiation shield to the second stage cryopanel, at least one of the orifices being closed by a removable closure secured to the orifice plate at the closed orifice.
- 5. A method of regulating flow of gas into a cryopump comprising providing an orifice plate at the inlet to the cryopump, the orifice plate having a plurality of orifices therein, selectively closing one of more orifices in the orifice plate by means of removable closures individually secured to the orifice plate, and thereafter cooling the cryopump, including the orifice plate and closures.
Specification