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Title: Low-cost, high-performance nonevaporable getter pumps using nonevaporable getter pills

Abstract

Nonevaporable getter (NEG) pumps are widely used for maintaining a clean ultrahigh vacuum (UHV) of ≤10{sup −8 }Pa because of their high pumping speeds for hydrogen (H{sub 2}) and active gases in the UHV region. In addition, they are oil free, evaporation free, sputtering free, sublimation free, magnetic field free, vibration free, economical, compact, lightweight, and energy saving. In the present paper, the authors report a new NEG pump which is composed of commercial 60 NEG pills (ϕ10 × 3 mm; 70 wt. % Zr, 24.6 wt. % V, and 5.4 wt. % Fe), titanium parts, a DN 40 conflat flange, and a tantalum heater. The NEG pills are vertically and radially aligned around the heater to maximize the effective area for pumping. After activation at 400 °C for 30 min, the pumping speeds of the NEG pump were measured with the orifice method. Pumping speeds of 140–130, 200–140, 190–130, and 35–17 l/s were estimated for H{sub 2}, CO, CO{sub 2}, and N{sub 2} gasses, respectively, in a pumped-quantity range of 0.01–0.1 Pa l. Since the NEG pump is composed of a heating unit and a NEG module, the pumping speeds can be improved by increasing the number of NEG modules. These NEG pumps are favorable alternatives to sputtering ionmore » pumps or titanium sublimation pumps.« less

Authors:
; ;  [1]; ;  [2]; ;  [3]
  1. Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)
  2. Faculty of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku 263-8522 (Japan)
  3. Institute of Materials Structure Science, KEK, 1-1 Oho, Tsukuba 305-0801 (Japan)
Publication Date:
OSTI Identifier:
22592841
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 34; Journal Issue: 5; Other Information: (c) 2016 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING; CARBON; CARBON DIOXIDE; CARBON MONOXIDE; GASES; GETTERS; HEATERS; HEATING; HYDROGEN; IONS; MAGNETIC FIELDS; ORIFICES; PUMPING; SPUTTERING; SUBLIMATION; TANTALUM; TITANIUM; VELOCITY

Citation Formats

Kodama, Hiraku, Ohno, Shinya, Tanaka, Masatoshi, Tanaka, Masato, Okudaira, Koji K., Mase, Kazuhiko, E-mail: mase@post.kek.jp, and Kikuchi, Takashi. Low-cost, high-performance nonevaporable getter pumps using nonevaporable getter pills. United States: N. p., 2016. Web. doi:10.1116/1.4961050.
Kodama, Hiraku, Ohno, Shinya, Tanaka, Masatoshi, Tanaka, Masato, Okudaira, Koji K., Mase, Kazuhiko, E-mail: mase@post.kek.jp, & Kikuchi, Takashi. Low-cost, high-performance nonevaporable getter pumps using nonevaporable getter pills. United States. doi:10.1116/1.4961050.
Kodama, Hiraku, Ohno, Shinya, Tanaka, Masatoshi, Tanaka, Masato, Okudaira, Koji K., Mase, Kazuhiko, E-mail: mase@post.kek.jp, and Kikuchi, Takashi. 2016. "Low-cost, high-performance nonevaporable getter pumps using nonevaporable getter pills". United States. doi:10.1116/1.4961050.
@article{osti_22592841,
title = {Low-cost, high-performance nonevaporable getter pumps using nonevaporable getter pills},
author = {Kodama, Hiraku and Ohno, Shinya and Tanaka, Masatoshi and Tanaka, Masato and Okudaira, Koji K. and Mase, Kazuhiko, E-mail: mase@post.kek.jp and Kikuchi, Takashi},
abstractNote = {Nonevaporable getter (NEG) pumps are widely used for maintaining a clean ultrahigh vacuum (UHV) of ≤10{sup −8 }Pa because of their high pumping speeds for hydrogen (H{sub 2}) and active gases in the UHV region. In addition, they are oil free, evaporation free, sputtering free, sublimation free, magnetic field free, vibration free, economical, compact, lightweight, and energy saving. In the present paper, the authors report a new NEG pump which is composed of commercial 60 NEG pills (ϕ10 × 3 mm; 70 wt. % Zr, 24.6 wt. % V, and 5.4 wt. % Fe), titanium parts, a DN 40 conflat flange, and a tantalum heater. The NEG pills are vertically and radially aligned around the heater to maximize the effective area for pumping. After activation at 400 °C for 30 min, the pumping speeds of the NEG pump were measured with the orifice method. Pumping speeds of 140–130, 200–140, 190–130, and 35–17 l/s were estimated for H{sub 2}, CO, CO{sub 2}, and N{sub 2} gasses, respectively, in a pumped-quantity range of 0.01–0.1 Pa l. Since the NEG pump is composed of a heating unit and a NEG module, the pumping speeds can be improved by increasing the number of NEG modules. These NEG pumps are favorable alternatives to sputtering ion pumps or titanium sublimation pumps.},
doi = {10.1116/1.4961050},
journal = {Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films},
number = 5,
volume = 34,
place = {United States},
year = 2016,
month = 9
}
  • Low-cost, high-performance non-evaporable getter (NEG) pumps were constructed using commercial NEG pills comprising 70 wt% Zr, 24.6 wt% V, and 5.4 wt% Fe, a conflat flange with an outer diameter of 70, 152, or 203 mm (DN 40 CF, DN 100 CF, and DN 160 CF, respectively), and a tantalum heater. After activation at 400 °C for 30 min, the pumping speeds of a DN 40 CF NEG pump measured with the orifice method were 47–40, 8–6, 24–17, and 19–15 L/s for H{sub 2}, N{sub 2}, CO, and CO{sub 2} gasses, respectively. NEG pumps using DN 100 CF and DNmore » 160 CF were also developed, and their pumping speeds are estimated. These NEG pumps are favorable alternatives to sputtering ion pumps in VSX beamlines because they do not produce hydrocarbons except during the activation period. The NEG pumps can also be used for accelerators, front ends, end stations, and differential pumping systems.« less
  • Auxiliary pumping means for nuclear fusion experiments are forseen inside the plasma chamber or in separated chambers (divertors), which must develop high pumping speed and capacity for H/sub 2/ and its isotopes as well as for impurities, and which must also meet special requirements regarding materials, space availability, and operating conditions. The fundamental properties of SORB-AC cartridges seem to make them particularly suitable for such pumping needs in fusion machines. A practical example is described for the case of a divertor section of such a machine. The pumping efficiency has been theoretically investigated using a Monte Carlo technique which allowsmore » the investigation of the influence of various geometrical and physical parameters.« less
  • A comparison of the performance of nonevaporable getter (NEG) films deposited using two different types of targets has been made to find the one that has the best pumping properties. For the first time, the NEG coating was deposited using a preformed Ti-Zr-V alloy target. The NEG film characterization and pumping properties have been studied in comparison with a film deposited using the commonly used three-wire twisted target. It was demonstrated that the alloy target produces a NEG coating with uniform composition both laterally and in depth. The composition of the film was found to be the same as themore » target. Film topography and microstructure with 5 nm grain sizes were found to be the same for both targets. The main result is that the activation temperature of the NEG coating deposited using the Ti-Zr-V alloy target is 160 deg. C, which is 20 deg. C lower than for NEG coatings deposited using three twisted wires.« less