Yokohama National University, Graduate School of Engineering Science, Yokohama, Japan
NIMS, Tsukuba, Ibaraki, Japan
KEK, Tsukuba, Japan
Sokendai, The Graduate University for Advanced Studies, Tsukuba, Japan
Yokohama National University, Yokohama, Japan
We have developed a zero-length conflat fin-type nonevaporable getter (NEG) pump that uses oxygen-free palladium/titanium (Pd/Ti)*. After baking at 150 degrees centigrade for 12 h, the pumping speeds of the NEG pump for H2 and CO were 2350~800 L/s and 1560~20 L/s, respectively, in the pumped-quantity range 0.01~30 Pa L. The morphologies of oxygen-free Pd/Ti films on the partition plates and the base plate were examined by scanning electron microscopy, scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The Ti was completely coated with Pd on the bottom, whereas the partition plates were covered by Pd/Ti nanostructures. Our new NEG pump is ideal for maintaining ultrahigh vacuums in the range 10-8 to 10-9 Pa, because (a) its pumping speeds for H2 and CO are quite large, (b) it can evacuate H2O and CO2 when an ionization gauge is used in the vacuum system, (3) it can be activated by baking at 150 degrees centigrade for 12 h, (c) its pumping speed does not decrease even after 9 cycles of pumping, baking, cooling to room temperature, and exposure to air**, (5) it requires neither a dedicated power supply nor electric feedthroughs, and (6) it is space saving and lightweight.
*T. Miyazawa et al., J. Vac. Sci. Technol. A 36, 051601 (2018).
**T. Kikuchi et al., AIP Conf. Proc. 2054, 060046 (2019).
