High-vacuum Pump of Orbitron Type: Electrophysical Principles of Work and Design Features

Authors V.В. Loboda1, J.Q. Ren1,2, M.Ya. Dovzhyk1, S.M. Khursenko1, M.C. Liang2

1 Sumy National Agrarian University, 40021 Sumy, Ukraine

2 Henan Institute of Science and Technology, 453003 Xinxiang, China

Е-mail loboda-v@i.ua
Issue Volume 11, Year 2019, Number 5
Dates Received 27 April 2019; revised manuscript received 08 October 2019; published online 25 October 2019
Citation V.В. Loboda, J.Q. Ren, M.Ya. Dovzhyk, et al., J. Nano- Electron. Phys. 11 No 5, 05010 (2019)
DOI https://doi.org/10.21272/jnep.11(5).05010
PACS Number(s) 07.30.Cy
Keywords Ultrahigh oil-free vacuum, Orbitron getter-ion vacuum pump, Residual atmosphere mass spectrum.

The article presents the results of studies of the operation of an orbitron getter-ion vacuum pump (OGIP) with nitrogen cryopanel. The paper presents the calculated average values of specific pumping speeds of various gases with a titanium film. A special feature of the OGIP is that the electrons therein emitted by the thermal cathode are used for both heating and sublimation of Ti, and for the ionization of gas molecules. The active gases are pumped out due to the chemisorption of the continuously renewed titanium film, the inert gases as a result of the ionization of their atoms by electrons moving in the cavity of the pump, the further accelerated movement of the formed ions to the wall of the pump casing by implanting them into the titanium film and “immurement” Ti deposited in it. The same accelerated electrons ionize a certain part of the molecules of active gases and heavy hydrocarbons, which are also sorbed by the titanium film. The article also describes the design features of the OGIP and its modes of operation. With the help of the MX7304A mass spectrometer, the composition of the residual atmosphere of the vacuum chamber was studied when it was pumped out to an ultrahigh vacuum, depending on the operating modes of OGIP. It was found that the main feature of the mass spectra of the residual atmosphere of the vacuum chamber when it is pumped out by OGIP is the complete absence of peaks with M > 44 amu in the mass spectra (molecules of heavy hydrocarbons). The main component of the residual atmosphere during water cooling of OGIP is methane CH4, the amount of which determines the ultimate vacuum in the chamber. When using nitrogen cryopanel, the main component of the residual atmosphere is H2O water vapor. The conclusion is drawn that the designed OGIP with nitrogen cryopanel is an effective pumping out tool for creating an ultrahigh oil-free vacuum in metal vacuum units that are fully heated.

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