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VA: Fachverband Vakuumphysik und Vakuumtechnik

VA 2: Ultra-high vacuum UHV

VA 2.1: Talk

Monday, March 23, 2009, 12:15–12:35, HSZ 101

New Methods to Achieve UHV/XHV with Refrigerator Cooled Cryopumps — •Dieter Müller — Oerlikon Leybold Vacuum GmbH, Köln, Deutschland

Besides beiing absolutely hydrocarbon-free, refrigerator-cooled cryopumps have unmatched pumping efficiency for water vapor among all high vacuum pumps. Thus we recommend them to use in UHV/XHV systems even during bakeout. The thermal balance of cryopumps in vacuum systems during baking is discussed and modifications of commercial pumps to withstand the heat flux into the pump are discussed. Practical results are shown reaching XHV pressures below 1E-12 mbar.