Characteristics of a cryogenic extreme high-vacuum chamber

Journal Article · Sat Jan 01 04:00:00 EST 1977 · J. Vac. Sci. Technol.; (United States)

DOI:https://doi.org/10.1116/1.569168· OSTI ID:7124790

Thompson, W; Hanrahan, S

We have designed, built, and tested a cryogenic chamber capable of pressures far below 10/sup -14/ Torr (approx.10/sup -12/ Pa) for surface studies. In a conventional vacuum system the surface desorbing and diffusing/desorbing vapors enter the chamber and are pumped to a dynamic equilibrium pressure by an ion pump or a cryopumping surface. In contrast, in the present system these vapors are prevented from first entering the cubic-foot chamber by cooling to 4.2 K all walls and all instruments sealed within it. This results in a nearly perfect vacuum (<1 atom/cm/sup 3/), which has been used to preserve sample surfaces, between measurements (i.e., 60 days). At higher chamber temperatures we have used an in situ quadrapole mass analyzer to measure the equilibrium partial pressures from 300 down to approx.30 K, where the last two gases, hydrogen and helium, drop below the instrument's detectability limit.

• Research Organization: IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 7124790
• Journal Information: J. Vac. Sci. Technol.; (United States), Journal Name: J. Vac. Sci. Technol.; (United States) Vol. 14:1; ISSN JVSTA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420700* -- Engineering-- Vacuum Engineering-- (-1987)
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CRYOGENIC FLUIDS
CRYOPUMPS
DESORPTION
DIFFUSION
ELEMENTS
FILMS
FLUIDS
HELIUM
HYDROGEN
LABORATORY EQUIPMENT
MASS SPECTROSCOPY
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PUMPS
RARE GASES
SENSITIVITY
SPECTROSCOPY
SURFACES
THERMODYNAMIC PROPERTIES
ULTRAHIGH VACUUM
VACUUM PUMPS
VACUUM SYSTEMS
VAPOR PRESSURE