Development and Validation of Simplified 1D Models for Hollow Cathode Analysis and Design
Several space electric propulsion devices, such as ion engines and Hall effect thrusters, use hollow cathodes as the electron sources for providing the necessary electrons for the ionization of the propellant and to neutralize the ion beam leaving the thruster. Since cathode performance is strongly tied with its geometry and size and plasma diagnostics is very difficult to be performed, simple numerical tools are required in order to determine optimal geometries and operative conditions for a given mission profile. The paper presents a preliminary design tool for orificed hollow cathodes. Two physical models compose the tool: a plasma model and a thermal model. A time-independent, volume-averaged model has been developed to determine plasma properties in the emitter and orifice regions. A Lumped Element Thermal Model has been also developed to compute temperature distributions and the respective gradients within the main cathode’s element. The study, conducted to validate the results of the models, shows that there is a good agreement with values and trends found in the available literature. The tool is able to estimate performances of new devices by the calculation of cathode working conditions for different geometries given device operating condition and insert material.
Unable to display preview. Download preview PDF.
- 5.C. J. Wordingham, P. Yves and C.R. Taunay “A Critical Review of Orificed Hollow Cathode Modeling”, 53rd AIAA/SAE/ASEE Joint Propulsion Conference, Atlanta, GA, July, 2017.Google Scholar
- 6.D. M. Goebel and I. Katz, “Fundamentals of Electric Propulsion: Ion and Hall Thrusters”, John Wiley and Sons, NJ, 2008.Google Scholar
- 8.M. Panelli, A. Smoraldi, F. Battista, “A Preliminary Design Tool for Hollow Cathodes”, 35thInternational Electric Propulsion Conference, IEPC2017, Georgia Institute of Technology, Atlanta, Georgia, USA October 8–12, 2017.Google Scholar
- 9.M.T. Domonkos, “Evaluation of Low-Current Orificed Hollow Cathodes”, PhD dissertation, Dept. Aerosp. Eng., Univ. Michigan, Ann Arbor, MI, USA, 1999.Google Scholar
- 11.F. P. Incropera, D.P. DeWitt, T.L. Bergman and Lavine, “Fundamentals of Heat and Mass Transfer”, Wiley, New York, NY, USA, 2006.Google Scholar
- 12.J. R. Howell and R. Siegel, “Thermal Radiation Heat Transfer, 5th ed”, Boca Raton, FL, USA, 2010.Google Scholar
- 14.D. Pedrini, R. Albertoni and F. Paganucci, “Theoretical Model of a Lanthanum Hexaboride Hollow Cathode”, 33rd International Electric Propulsion Conference, Washington, D.C., USA, 2013.Google Scholar
- 15.P. J. Wilbur, “Advanced Ion Thruster Research Annual Report, I”, NASA CR-168340, 1984.Google Scholar
- 18.M. Mandell and I. Katz, “Theory of Hollow Cathode Operation in Spot and Plume Modes” 30th Joint Propulsion Conference and Exhibit, Indianapolis, U.S.A., 1994.Google Scholar