Accession Number : AD0481222

Title :   THE THEORY AND CONSTRUCTION OF A LIQUID HELIUM CRYOGENIC PUMP.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : LaChance, George M.

Report Date : 1964

Pagination or Media Count : 46

Abstract : Cryogenic pumping is a means of maintaining a high vacuum with large gas in-leakage rates. This is accomplished by the condensation and freezing of the gas molecules onto a surface that is maintained at a temperature well below the freezing point of the gas. A liquid helium filled batch process cryogenic pumping system was constructed and instrumented. The vacuum chamber and roughing system were obtained by the modification and redesign of an existing vacuum furnace. The theory of cryogenic pumping is presented and an approach developed for the evaluation of the cryopump performance. (Author)

Descriptors :   (*CRYOPUMPING, THEORY), LIQUEFIED GASES, HELIUM, PUMPS, DESIGN, CONSTRUCTION, ASSEMBLY, PERFORMANCE(ENGINEERING), INSTRUMENTATION, HEAT SHIELDS, VACUUM APPARATUS.

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE