MEASUREMENT STUDY FOR VACUUM MATERIALS OUTGASSING

The experiment for metal materials outgassing rates property was performed on the vacuum material outgassing rate apparatus. The constant volume method, the orifice throughput method and switching between two pumping paths (SPP) method were adopted for the experiment study. The results show that the ultimate pressure of apparatus is 9. 2×10^-9 Pa. After half hour, the outgassing rate of copper, allium alloy and 304 stainless steel is 2. 34×10^-8 Pa·m³·s^-1·cm^-2, 1. 83×10^-9 Pa·m³·s^-1·cm^-2、8. 48×10^-11 Pa·m³·s^-1·cm^-2, respectively. The background gas species of apparatus by quadruple mass-spectrometer are H₂, N₂/CO, H₂O and CO₂. The materials outgassing species are mainly N₂/CO and H₂O. Additionally, the copper outgassing rate measured by three methods increases with elevated temperature.