| 摘要 |
<p>Cryopumping speed of nitrogen, helium, hydrogen and neon can be increased by omitting the chevron baffle in a conventional cryopump and preventing incident radiation of about 300 DEG K. from striking surfaces used to cryosorb helium, hydrogen and neon. An apparatus is disclosed utilizing three pumping surfaces created from open ended opposed nested cylinders. A radiation absorbent coating is placed on one of the surfaces to shield the helium, hydrogen and neon pumping surface. Refrigeration can be provided by a two-stage closed cycle cryogenic refrigerator.</p> |
