AVS 59th Annual International Symposium and Exhibition
    Vacuum Technology Tuesday Sessions
       Session VT-TuP

Paper VT-TuP4
Flow of a Binary Gas Mixture Into Vacuum: Experiment, Models, Simulation

Tuesday, October 30, 2012, 6:00 pm, Room Central Hall

Session: Vacuum Technology Poster Session and Student-built Vacuum System Poster Competition
Presenter: M. Vukovic, Tokyo Electron, US Holdings
Authors: M. Vukovic, Tokyo Electron, US Holdings
R. Johnsen, University of Pittsburgh
Correspondent: Click to Email
The flow of gas through a small orifice into vacuum was experimentally analyzed by Fujimoto & Usami (1984). They developed a formula to describe the flow conductance as function of the orifice rarefaction parameter. R. Johnsen and B. K. Chatterjee (2011) measured the flow rate of a minority gas (H2, O2, CO2) in a carrier gas (He, Ar) using the University of Pittsburgh ion drift tube experiment. Using the hard-sphere collision potential they also developed a heuristic formula to model the minority gas conductance rate as function of the carrier gas rarefaction parameter. In this work we generalize their formula to arbitrary intermolecular potentials. We also develop an alternative model and formula that successfully describes the data. We will describe the ion-drift tube experiment, discuss the two models and formulas. We will also present results of DSMC simulations using the Graem Bird's DS2V code (http://www.gab.com.au).

T. Fujimoto and M. Usami, ASME Trans. J. Fluids Eng. 106, 367 (1984).

R. Johnsen and B. K. Chatterjee J. Vac. Sci. Technol. A 29, 011002-1 (2011)