초록 ▼

A two stage cryopump with an improved first stage for condensing water vapor at high speed independently of the rate of gas flow into the second stage and without increasing the heat load on the cryopump. The cryopump utilizes a low profile high precision variable aperture to control flow to a lower

A two stage cryopump with an improved first stage for condensing water vapor at high speed independently of the rate of gas flow into the second stage and without increasing the heat load on the cryopump. The cryopump utilizes a low profile high precision variable aperture to control flow to a lower baffle obstructing the mouth of a shroud containing the second stage, utilizes a support shaft mounted on the top of the lower baffle and extending upstream through the aperture, and utilizes an upper baffle mounted on the top of the shaft in thermal contact with the lower baffle to condense water vapor before reaching the aperture.

대표청구항 ▼

A cryopump comprising: housing means including walls having inner sides forming an interior cavity with a top opening, and with a port; elongated cooling means extending through said port into said cavity and including first and second cooling cylinders; first stage condenser means disposed within s

A cryopump comprising: housing means including walls having inner sides forming an interior cavity with a top opening, and with a port; elongated cooling means extending through said port into said cavity and including first and second cooling cylinders; first stage condenser means disposed within said cavity and including shroud means supported by said cooling means and having inside surfaces surrounding the distal end of said cooling means and having an upwardly opening throat, lower baffle means affixed to said shroud means and obstructing the throat thereof, said lower baffle means being thermally connected through said shroud means to said cooling means, a thermally conductive support shaft having a lower end mounted on the top of said lower baffle means and having an upper end extending towards said top opening, and upper baffle means mounted on said upper end in a position above said throat and below said top opening; second stage condenser means disposed within said shroud means and in thermal contact with said cooling means; and throttle valve means mounted within said cavity in thermal isolation from said condenser means and from said cooling means, and dividing said cavity into an upper portion and a lower portion, said valve means forming a variable aperture between said upper and lower baffle means for controlling the rate of flow of gases between said upper and lower portions.