DEVELOPMENT AND EVALUATION OF A CRYODEPOSIT SORPTION PUMP CAPABLE OF PUMPING HELIUM
Abstract
A small cryogenically cooled pump has been developed which is capable of pumping all gases including helium and hydrogen. Its low base pressures makes it suitable for use in ultrahigh vacuum systems, and its high pumping speed for all gases is maintained up to pressures in the 10 to the -6th power torr range. The pump operates by sorbing the normally noncondensable gases in a layer of argon cryofrost which is predeposited on its liquid-helium-cooled surface. As with any sorption pump, the sorbent eventually becomes saturated, and the sorbate partial pressure starts to rise. However, unlike most sorbent pumps, this one can be reactivated simply by recoating the surface with a fresh layer of sorbent in situ. Sorption isotherms have been obtained for He on 4.2 degrees K cryodeposits of N2, A, O2, and CO2 over a pressure range from 10 to the minus eighth power to .001 torr.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1968
- Accession Number
- AD0675207
Entities
People
- J. D. Haygood
- Ronald Dawbarn
Organizations
- Arnold Engineering Development Complex