Author: Kikuchi, T.
Paper Title Page
TUOA03 Zero-Length Conflat Fin-Type Nonevaporable Getter Pump Coated with Oxygen-Free Palladium/Titanium 107
 
  • Y. Sato
    Yokohama National University, Graduate School of Engineering Science, Yokohama, Japan
  • A.H. Hashimoto, M. Yamanaka
    NIMS, Tsukuba, Ibaraki, Japan
  • T. Kikuchi, K. Mase
    KEK, Tsukuba, Japan
  • T. Miyazawa
    Sokendai, The Graduate University for Advanced Studies, Tsukuba, Japan
  • S. Ohno
    Yokohama National University, Yokohama, Japan
 
  Funding: This work was partly supported by a JSPS KAKENHI (JP19K05280), a TIA-Kakehashi (TK19-035), and the 2019 Takahashi Industrial Economic Research Foundation grant, and was supported by NIMS TEM Station.
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).
 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-TUOA03  
About • paper received ※ 30 July 2021       paper accepted ※ 14 October 2021       issue date ※ 08 November 2021  
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TUPA01 Oxygen-Free Titanium Thin Film as a New Nonevaporable Getter with an Activation Temperature as Low as 185 °C 119
 
  • M. Ono, I. Yoshikawa, K. Yoshioka
    University of Tokyo, Kashiwa, Japan
  • T. Kikuchi, K. Mase
    KEK, Tsukuba, Japan
  • K. Mase
    Sokendai, The Graduate University for Advanced Studies, Tsukuba, Japan
  • Y. Masuda, Y. Nakayama
    Tokyo University of Science, Noda, Japan
  • S. Ohno
    Yokohama National University, Yokohama, Japan
  • K. Ozawa
    TIT, Tokyo, Japan
  • Y. Sato
    Yokohama National University, Graduate School of Engineering Science, Yokohama, Japan
 
  Funding: This work was partly supported by JSPS KAKENHI (17K05067, 19K05280) and TIA-Kakehashi (TK19-035, TK20-026). The XPS measurements were performed under the Photon Factory proposal (2018S2-005).
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.
*C. Benvenuti et al., J. Vac. Sci. Technol. A 16, 148 (1998).
**T. Miyazawa et al., Vac. Surf. Sci. 61, 227 (2018).
***KEK, patent pending, WO2018097325 (Nov. 28, 2017).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2020-TUPA01  
About • paper received ※ 30 July 2021       paper accepted ※ 14 October 2021       issue date ※ 01 November 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)