TY - CONF AU - Ono, M. AU - Kikuchi, T. AU - Mase, K. AU - Masuda, Y. AU - Nakayama, Y. AU - Ohno, S. AU - Ozawa, K. AU - Sato, Y. AU - Yoshikawa, I. AU - Yoshioka, K. ED - Jaski, Yifei ED - Den Hartog, Patric ED - Jaje, Kelly ED - Schaa, Volker R.W. TI - Oxygen-Free Titanium Thin Film as a New Nonevaporable Getter with an Activation Temperature as Low as 185 °C J2 - Proc. of MEDSI2020, Chicago, IL, USA, 24-29 July 2021 CY - Chicago, IL, USA T2 - Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation T3 - 11 LA - english AB - Although nonevaporable getter (NEG) pumps are widely used in synchrotron radiation facilities, pure metal Titanium (Ti) has not been used as a NEG because the activation temperature of a Ti thin film deposited by DC magnetron sputtering was reported to be 350-400 °C*. Recently Miyazawa et al. found that high-purity Ti deposited under ultra-high vacuum (UHV) followed by N₂ introduction works as a NEG with an activation temperature of 185 °C**,***. Since the concentration of impurities such as O, C, and N in the Ti thin film prepared by this method is 0.05% or less, we named this as oxygen-free Ti. In this study, we evaluated the pumping properties of oxygen-free Ti thin films after high-purity N₂ introduction by total and partial pressure measurements. A vacuum vessel with oxygen-free Ti deposited on the inner walls was found to pump H₂, H₂O, O₂, CO and CO₂ even after 30 cycles of high purity N₂ introduction, air exposure, pumping, and baking at 185 °C. Furthermore, we analyzed the oxygen-free Ti thin films after high-purity N₂ or air introduction by synchrotron radiation X-ray photoelectron spectroscopy. The results show that more TiN was formed when high-purity N₂ was introduced after oxygen-free Ti deposition. High purity of the Ti thin film and TiN formation on the surface seem to be responsible for the reduced activation temperature as low as 185 °C. PB - JACoW Publishing CP - Geneva, Switzerland SP - 119 EP - 122 KW - vacuum KW - site KW - quadrupole KW - synchrotron-radiation KW - synchrotron DA - 2021/10 PY - 2021 SN - 2673-5520 SN - 978-3-95450-229-5 DO - doi:10.18429/JACoW-MEDSI2020-TUPA01 UR - https://jacow.org/medsi2020/papers/tupa01.pdf ER -