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Room temperature spectra

After closing the vacuum vessel, pumping will bring the pressure below mBar after one day, but further decrease in the pressure occurs extremely slowly. As the RGA requires a pressure below mBar, baking of the vessel is necessary before a room temperature measurement can be made. Before the measurement, baking was performed for two days, followed by cooling down to room temperature. The pressure was then mBar. Spectra of the vacuum vessel as well as the RGA background were obtained, and these are shown in figure 8. Only /AMU ratios lower than 60 are shown, to provide more detail and because no features were different from the cold spectrum. The background was scaled up by a factor of 1.7 to fit the NOTCam spectrum. At room temperature, the differences are less pronounced, especially the and pressures are unchanged. The dominating outgassing components from the vessel are , and , i.e. basically atmospheric air. At a lower level, peaks from NO, Ar and Ne are seen.

 



Anlaug Amanda Kaas
Tue Jun 19 15:56:27 ACT 2001