HIGH CONDUCTANCE CRYOPUMP FOR TYPE III GAS PUMPING

摘要

A cryopump provides for high pumping speed of Type III gases. An open configuration of a frontal array provides high conductance of gases into a radiation shield which is shaped to focus gases toward a second stage array. The second stage array has an open configuration of baffles coated with adsorbent. Substantially all of the adsorbent has a direct line of sight to the radiation shield or to the opening in the radiation shield, and substantially all of the baffles are coated with adsorbent. In one form, the second stage cryopump array comprises an array of discs fanned to define a generally ball shaped envelope.