Accession Number:

ADA393879

Title:

Measurement of the Lowest Pressures in Space and the Laboratory

Descriptive Note:

Technical note

Corporate Author:

GEOPHYSICS CORP OF AMERICA BEDFORD MA

Personal Author(s):

• Kreisman, Wallace

Report Date:

1965-02-01

Pagination or Media Count:

188.0

Abstract:

A description is given of the design, construction and operational characteristics of two demountable, metal ultra high vacuum systems, a mercury diffusion pump system and a combination liquid helium cryopumpion pump system. The diffusion pump system attained pressures as low as 10exp -l3 torr and was used for low pressure vacuum gauge calibration. The liquid helium cryopump system reached pressures in the low 10exp -11 torr region with only limited bake outs and exhibited a clean residual gas mass spectrum. The two systems were studied to determine their low pressure limitations and sources of residual gas.

Descriptors:

• *SPACE ENVIRONMENTS
• *LOW PRESSURE
• *MERCURY
• *CRYOPUMPING
• *VACUUM PUMPS
• *LIQUID HELIUM
• *DIFFUSION PUMPS
• GASES
• RESIDUAL STRESS
• CALIBRATION
• MASS SPECTRA
• ION PUMPS

Subject Categories:

• Inorganic Chemistry
• Pumps, Filters, Pipes, Tubing, Fittings and Valves

Distribution Statement:

APPROVED FOR PUBLIC RELEASE