Ionization Gauge

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Jie Tang - One of the best experts on this subject based on the ideXlab platform.

Yuanchao Yang - One of the best experts on this subject based on the ideXlab platform.

Sam-yong Woo - One of the best experts on this subject based on the ideXlab platform.

  • Application of carbon nanotube field emission effect to an Ionization Gauge
    Appl. Phys. Lett. Additional information on Appl. Phys. Lett. Journal Homepage, 2005
    Co-Authors: In-mook Choi, Sam-yong Woo
    Abstract:

    Using the field emission effect of a carbon nanotube ͑CNT͒, we characterized a new type of technology for detecting low pressure. The fabricated low pressure sensor is of a triode type, consisting of a cathode ͑carbon nanotubes field emitter arrays͒, a grid, and a collector. The Gauge described here has a triode configuration similar to that of a conventional hot cathode Ionization Gauge but also has a cold emission source. Due to the excellent field emission characteristics of CNT, it is possible to make a cost effective cold cathode type Ionization Gauge. For an effective CNT cathode, we used the screen-printing method and also, we controlled the collector and the grid potentials in order to obtain a high Ionization current. We found that the ratio of the Ionization current to the CNT cathode current changes according to the pressure in the chamber. In short, we elaborate the various metrological characteristics of a home-made pressure sensor that uses CNTs.

  • Ionization Gauge by carbon nanotube field emission
    JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY, 2005
    Co-Authors: In-mook Choi, Sam-yong Woo, Bong Seok Kim
    Abstract:

    A newly developed Ionization Gauge using carbon nanotube(CNT) field emission effect has been designed and manufactured. The fabricated Ionization Gauge is of a triode type, consisting of a cathode (carbon nanotube field emitter arrays), a grid and a collector. The principle involved here is that for a constant number of electrons available for Ionization emitted from carbon nanotube arrays by the grid potential, a constant fraction of gas will be ionized and the number of ions collected in the collector will be proportional to the number of gas molecules in the chamber traversed by the electrons. Due to the excellent field emission characteristics of CNT, it is possible to make a cost effective cold cathode Ionization Gauge. A screen-printing method has been used to make the CNT cathode. The glass grid with Cr deposited by E-beam has been put on the cathode with a gap of 200 mu m between the two electrodes. Using the voltage applied to the grid, the electrons emitted from the carbon nanotube ionize gas molecules in the chamber and the ionized molecules are gathered in the collector. At this time, the collector voltage is maintained at a lower level than that of the grid voltage to obtain a large Ionization ratio. The current detected in the collector is proportional to the pressure in the chamber. The Ionization characteristics are dependent on the gas and the voltage applied to the grid and collector. In this paper we have shown the various metrological characteristics of the simple pressure sensor utilizing carbon nanotube.

Shoushan Fan - One of the best experts on this subject based on the ideXlab platform.

  • A low-vacuum Ionization Gauge with HfC-modified carbon nanotube field emitters
    Applied Physics Letters, 2008
    Co-Authors: Yuanchao Yang, Liang Liu, Jie Tang, Li Qian, Shoushan Fan
    Abstract:

    We have developed an Ionization Gauge with a carbon nanotube (CNT) cold cathode for low-vacuum applications. The Gauge features a small grid-collector gap for low sensitivity factor and a HfC-coated CNT field-emission cathode. The vacuum is indicated by the ratio of the ion current to the electron-emission current, and good linearity is obtained in He, Ar, N(2), and air throughout the vacuum range from 10(-7) to 1 Torr. A 20 nm layer of polycrystalline HfC sputtered on CNT cathode improves the emission stability and the lifetime in low vacuum. (C) 2008 American Institute of Physics.

Li Qian - One of the best experts on this subject based on the ideXlab platform.

  • a low vacuum Ionization Gauge with hfc modified carbon nanotube field emitters
    Applied Physics Letters, 2008
    Co-Authors: Yuanchao Yang, Li Qian, Jie Tang
    Abstract:

    We have developed an Ionization Gauge with a carbon nanotube (CNT) cold cathode for low-vacuum applications. The Gauge features a small grid-collector gap for low sensitivity factor and a HfC-coated CNT field-emission cathode. The vacuum is indicated by the ratio of the ion current to the electron-emission current, and good linearity is obtained in He, Ar, N2, and air throughout the vacuum range from 10−7to1Torr. A 20nm layer of polycrystalline HfC sputtered on CNT cathode improves the emission stability and the lifetime in low vacuum.

  • A low-vacuum Ionization Gauge with HfC-modified carbon nanotube field emitters
    Applied Physics Letters, 2008
    Co-Authors: Yuanchao Yang, Liang Liu, Jie Tang, Li Qian, Shoushan Fan
    Abstract:

    We have developed an Ionization Gauge with a carbon nanotube (CNT) cold cathode for low-vacuum applications. The Gauge features a small grid-collector gap for low sensitivity factor and a HfC-coated CNT field-emission cathode. The vacuum is indicated by the ratio of the ion current to the electron-emission current, and good linearity is obtained in He, Ar, N(2), and air throughout the vacuum range from 10(-7) to 1 Torr. A 20 nm layer of polycrystalline HfC sputtered on CNT cathode improves the emission stability and the lifetime in low vacuum. (C) 2008 American Institute of Physics.

  • conventional triode Ionization Gauge with carbon nanotube cold electron emitter
    Journal of Vacuum Science and Technology, 2008
    Co-Authors: Lin Xiao, Li Qian
    Abstract:

    The authors presented a conventional triode Ionization Gauge with a linear-type carbon nanotube cold electron emitter, which was made by painting technology on a nickel wire. The Gauge used the ratio of the ion current to the electron current to indicate the vacuum. Although there was fluctuation in the cathode’s emission current, the ratio of the ion current to the electron current kept stable with a variation of about ±10% in each pressure decade from 10−7to10−3torr. The Gauge showed good measurement linearity in the vacuum range from 10−6to10−3torr.The authors presented a conventional triode Ionization Gauge with a linear-type carbon nanotube cold electron emitter, which was made by painting technology on a nickel wire. The Gauge used the ratio of the ion current to the electron current to indicate the vacuum. Although there was fluctuation in the cathode’s emission current, the ratio of the ion current to the electron current kept stable with a variation of about ±10% in each pressure decade from 10−7to10−3torr. The Gauge showed good measurement linearity in the vacuum range from 10−6to10−3torr.