Cryopump arrangement for improved pump speed

A pumping apparatus, comprising:

• an overpressure containment structure, defining a cavity, the overpressure containment structure having an opening;
• a cryopump, having a body and a front surface, the cryopump disposed in the cavity, the cavity being adjacent to a processing chamber;
• a movable gate to separate the cavity from the processing chamber, the movable gate having an open position and a closed position;
• a bearing shaft, attached to the body of the cryopump, passing through the opening in the overpressure containment structure;
• an external collar surrounding the bearing shaft, providing a vacuum seal between the cavity and an exterior of the cavity;
• a bellows attached at one end to the body of the cryopump and attached at a second end to a wall of the cavity so as to divide the cavity into a first portion and a second portion, where the first portion is always isolated from the processing chamber, wherein the opening and the bearing shaft are disposed in the first portion and the front surface of the cryopump is disposed in the second portion;
• and
• an actuator, disposed outside the cavity, in communication with the bearing shaft to move the cryopump between a first operational position where the front surface extends beyond the movable gate toward the processing chamber when the movable gate is in the open position, and a second regeneration position, where the front surface is disposed behind the movable gate, so that the movable gate can move to the closed position, isolating the cavity from the processing chamber.