Shinku

Show abstractHide abstract

Residual gas analysis with a quadrupole gas analyser were carried out in order to know the variation of residual gas composition that occurred when a hot metal surface was placed in vacua of 10^-6-10^-7Torr. The measurements were performed with a glass bulb containing a filament (W, Re, Ta, Nb or Pt) of hair pin type or with a carbon-filament electric-bulb. The results are obtained as follows : (1) When the filament is heated at 1000-2000°C, H₂, CO and CO₂ increase, and H, H₂O (except carbon filaments) and O₂ decrease. These changes are due to reactions of residual gases with the heated metal surfaces. Decrease of H₂O has a close relation with an increase of H2 and a decrease of H. Increases of CO and CO₂ (on W and C) relate to decrease of 0₂. (2) Changes of residual gas composition depend on filament materials. Especially, the carbon filament shows quite different behaviors from those of other filaments. (3) Behaviors of m/e 41 ions with the change of filament temperature (on Re, W and C) are much different from those of molecules (or ions) with other masses. (4) While the variation of residual gas composition with W or Nb becomes drastic with filament temperature, the variation with Re shows saturation. The change with a heated W surface is more moderate than that with Re in the temperature range lower than 1600°C, and larger in the range higher than 1600°C.

View full abstract

Download PDF (901K)

Register with J-STAGE for free!