Pumping of methane by St707 at low temperatures
A simple means of pumping small leak rates of methane is frequently required in long-term sealed-off devices such as evacuated solar absorbers. In this paper we examine, in this context, a chemisorption or catalytic pump the SAES getter St707. After suitable activation in an ultrahigh vacuum system a small sample of St707 (2.7 x 3 cm), with heater external to the vacuum system, was exposed to a methane leak as the sample temperature was raised in steps from room temperature to 400 /sup 0/C, the highest temperature used. Pumping was first detected at 100 /sup 0/C and at 400 /sup 0/C the pumping speed was 2 x 10/sup -3/ l s/sup -1/ cm/sup -2/ (pumping area assumed 8 cm/sup 2/), after 0.34 Torr l of methane had been pumped. Care was taken to distinguish these small pumping speeds from ionic pumping by the gages. The conclusion is that the St707 getter is suitable as a methane pump of low speed at low temperatures and pressures.
- Research Organization:
- Electrical Engineering Division, National Research Council, Ottawa, Canada K1A OR6
- OSTI ID:
- 5755970
- Journal Information:
- J. Vac. Sci. Technol., A; (United States), Journal Name: J. Vac. Sci. Technol., A; (United States) Vol. 4:3; ISSN JVTAD
- Country of Publication:
- United States
- Language:
- English
Similar Records
Evaluation of Zr-V-Fe getter pump for uhv system
Pumping of methane by a low power hot-cathode ion pump/gage
Related Subjects
360104* -- Metals & Alloys-- Physical Properties
42 ENGINEERING
420700 -- Engineering-- Vacuum Engineering-- (-1987)
ALKANES
ALLOYS
CHEMICAL REACTIONS
CHEMISORPTION
EQUIPMENT
GETTERING
GETTERS
HYDROCARBONS
IRON ALLOYS
LABORATORY EQUIPMENT
LEAKS
MEASURING INSTRUMENTS
METHANE
ORGANIC COMPOUNDS
PRESSURE GAGES
PUMPING
PUMPS
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
VACUUM GAGES
VACUUM PUMPS
VANADIUM ALLOYS
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS