Patent ID: 9700812
Date: 2017-07-11
CPC Classifications: B01D,F04B

Claim:
1. A cryopump comprising: a cryopump inlet; a cryopump bottom axially remote from the cryopump inlet; a cryopanel assembly comprising a top panel located closest to the cryopump inlet and a plurality of cryopanels arranged between the top panel and the cryopump bottom, the cryopanels arranged axially spaced apart from each other at an axial interval, each of the cryopanels comprising a front cryopanel surface directed to the cryopump inlet and comprising a front adsorption area thereon and a back cryopanel surface directed to the cryopump bottom and comprising a back adsorption area thereon; a radiation shield forming a gas receiving space that surrounds the cryopanel assembly; and a radiation cover disposed in the cryopump inlet, the radiation cover comprising a main plate located at a first position in the cryopanel inlet that corresponds to the cryopanel assembly, the radiation cover faces the top panel, an axial distance from the main plate to the top panel being smaller than the axial interval of the cryopanels, and a louver portion located at a second position in the cryopanel inlet that corresponds to the gas receiving space, wherein the entire surface of the main plate is flat, the main plate comprises a flat periphery radially extending in a plane perpendicular to an axial direction of the cryopump, wherein the entire surface for each of the cryopanels is flat, a distance between the cryopanel assembly and the main plate is 5 cm or less.