Outgassing rate testbed for in-operation analysis of powered and heated assemblies

Abstract

We introduce a new apparatus for measuring the outgassing rate of assemblies and functional units. Outgassing rates given in the literature, if available, are mostly insufficient to plan and set up a vacuum system, more so if commercial parts, preassembled items, or complex electronics with unknown components are deployed. Outgassing rates have a severe impact on the required pumping speed in ultrahigh vacuum systems and they change if the samples are powered or heated. The newly built apparatus uses the throughput method to measure outgassing rates. It can house probes with a size of 0.10×0.10×0.13m3 and supplies electrical currents of up to 5 A. In addition, a heater can establish temperatures of up to 200 °C directly. A procedure is given to identify the main gas inputs and to retrieve data with a lower limit of 1.5×10−8Pam3s−1 after 100 h in vacuum. In this paper, we present the experimental setup and first results for samples of polytetrafluorethylene, polyamide (PA6), Viton (1A), and oxygen-free high thermal conductivity copper at room temperature.