Use of the Omegatron in the Determination of Parameters Affecting Limiting Pressures in Vacuum Devices

Abstract

The omegatron mass spectrometer has been used to determine residual gases in vacuum systems, including ion pump systems. The predominant residual gas in ion pumps was found to be methane, while the gases found in oil diffusion pump systems include water vapor and carbon monoxide. Analysis has been performed to determine the residual gases in vacuum tubes which are difficult to outgas, and conditions that lead to considerable hydrogen content are described. Examples of the use of the omegatron mass spectrometer as a tool in aiding solution of outgassing problems are given.