Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Cryosorption pumping of deuterium by MS-5A at temperatures above 4. 2 K for fusion reactor applications

Journal Article · · J. Vac. Sci. Technol.; (United States)
DOI:https://doi.org/10.1116/1.569501· OSTI ID:6839668
An excalibur CVR-1106 cryosorption pump was fitted with a special cooling system to permit measurement of deuterium pumping speeds at temperatures between 6 and 20 K. Pumping speeds were found to be a function of feed rate, loading prior to each run, loading during runs, and thermal treatment between runs. At feed rates <3 x 10/sup -/4 Torr l s/sup -/1 cm/sup -/2, speeds were near 1 l s/sup -/1 cm/sup -/2 initially and declined monotonically with loading. At high feed rates, speeds reached a higher maximum (approx.3 l s/sup -/1 cm/sup -/2) but also generally declined with loading; however, after 50--100 Torr l had accumulated, the pump underwent a spontaneous transition which effected a return to the original (high) pumping speed. This transition was accompanied by pressure spikes in the test chamber and temperature spikes in the sieve panel. Initial speeds for each consecutive run equaled the final speed for the preceding run if the pump was maintained at operating temperature; however, if it was warmed to 77 K and recooled, a restoration to the maximum speed was observed at the beginning of the next run.
Research Organization:
Chemical Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
OSTI ID:
6839668
Journal Information:
J. Vac. Sci. Technol.; (United States), Journal Name: J. Vac. Sci. Technol.; (United States) Vol. 15:2; ISSN JVSTA
Country of Publication:
United States
Language:
English