Effect of environmental humidity on rate of thermal outgassing

This investigation presents a super-dry venting system that allows the rate of thermal outgassing of an aluminum chamber (length 2 m) to return rapidly to 1 × 10−13 mbar L s−1 cm−2 in 4 h without baking. A glove box and an air shower, which provided dehumidified environments with water vapor concentrations of 0.1 ppm and 5 ppm respectively, were utilized to assess the effect of environmental humidity on the rate of thermal outgassing. With super-dry nitrogen venting inside and exposure to the glove box, a thermal outgassing rate of q1 ∼ 1 × 10−11 mbar L s−1 cm−2 was achieved.