2018 年 61 巻 4 号 p. 227-235
We have developed a new non-evaporable getter (NEG) coating using titanium and palladium vacuum sublimation. The inner wall of the test chamber was coated with a 1-µm Ti thin film using the Ti sublimation pumps under a vacuum of 6.5×10−6 Pa (Ti-coated chamber). This chamber was then coated with a 10-nm Pd thin film using the Pd sublimation filament under a vacuum of 2.4×10−4 Pa (Pd/Ti-coated chamber). The uncoated, Ti-coated, and Pd/Ti-coated chambers were baked for 6 h at a maximum temperature of 185℃. Five hours after closing the valve, the pressures in the Pd/Ti-coated chamber were about 1.4×10−6 Pa even after six heating–venting cycles. The relatively low activation temperature was attributed to the low concentration of oxygen in the Pd/Ti thin films. The Pd/Ti coating can be used for vacuum systems that are frequently vented.
