Journal Articles

Polk, J. E., Capece, A. M., Mikellides, I. G., Katz, I., “Barium Depletion in Hollow Cathode Emitters,” Journal of Applied Physics, Vol. 119, 2016, pp. 023303 (1-11).

Lopez Ortega, A., Katz, I., Mikellides, I. G., and Goebel, D. M., "Self-Consistent Model of a High-Power Hall Thruster Plume," IEEE Transactions on Plasma Science, 43, 9, 2875-2886, 2015.

Sekerak, M. J., Longmier, B. W., Gallimore, A. D., Brown, D. L., Hofer, R. R., and Polk, J. E., "Azimuthal Spoke Propagation in Hall Effect Thrusters," IEEE Transactions on Plasma Science, 43, 1, 72-85, January 2015.

Conversano, R. W., Goebel, D. M., Hofer, R. R., Matlock, T. S., and Wirz, R. E., "Development and Initial Testing of a Magnetically Shielded Miniature Hall Thruster," IEEE Transactions on Plasma Science, 43, 1, 103-117, January 2015.

Goebel, D. M., Hofer, R. R., Mikellides, I. G., Katz, I., Polk, J. E., and Dotson, B. N., "Conducting Wall Hall Thrusters," IEEE Transactions on Plasma Science, 43, 1, 118-126, January 2015.

Mikellides, I. G., Goebel, D. M., Jorns, B. A., Polk, J. E., and Guerrero, P. "Numerical Simulations of the Partially-ionized Gas in a 100-A LaB6 Hollow Cathode," IEEE Transactions on Plasma Science, 43, 1, 173-184, January 2015.

Oh, D. Y., Snyder, J. S., Goebel, D. M., Hofer, R. R., and Randolph, T. M., "Solar Electric Propulsion for Discovery-Class Missions," Journal of Spacecraft and Rockets, 51, 6 , 1822-1835 (2014).

Mikellides, I. G., Hofer, R. R., Katz, I., and Goebel, D. M., "Magnetic Shielding of Hall Thrusters at High Discharge Voltages," Journal of Applied Physics, 116, 053302 (2014).

Jorns, B. A. and Hofer, R. R., "Plasma Oscillations in a 6-kW Magnetically Shielded Hall Thruster," Physics of Plasmas 21, 5, 053512 (2014).

Polk, J. E., Mikellides, I. G., Capece, A. M., and Katz, I., "The Effect of Cathode Geometry on Barium Transport in Hollow Cathode Plasmas," Journal of Applied Physics 115, 18, 183301 (2014).

Capece, A. M., Polk, J. E., Mikellides, I. G., and Shepherd, J. E., "Oxygen Transport in the Internal Xenon Plasma of a Dispenser Hollow Cathode," Journal of Applied Physics 115, 15, 153302 (2014).

Mikellides, I. G., Katz, I., Hofer, R. R., and Goebel, D. M., "Magnetic shielding of a laboratory Hall thruster. I. Theory and validation," J. Appl. Phys., 115, 043303 (2014).

Hofer, R. R., Goebel, D. M., Mikellides, I. G., and Katz, I., "Magnetic shielding of a laboratory Hall thruster. II. Experiments," J. Appl. Phys., 115, 043304 (2014).

Snyder, J. S., Brophy, J. R., Hofer, R. R., Goebel, D. M., and Katz, I.. "Experimental Investigation of a Direct-Drive Hall Thruster and Solar Array System," Journal of Spacecraft and Rockets 51, 1, 360-373 (2014).

Goebel, D. M. and Chu, E., "High-Current Lanthanum Hexaboride Hollow Cathode for High-Power Hall Thrusters," Journal of Propulsion and Power 30, 1, 35-40 (2014).

Chu, E., Goebel, D. M., and Wirz, R. E.. "Reduction of Energetic Ion Production in Hollow Cathodes by External Gas Injection", Journal of Propulsion and Power, Vol. 29, No. 5, pp. 1155-1163 (2013).

Mikellides, I. G., Katz, I., Hofer, R. R., and Goebel, D. M., "Magnetic Shielding of Walls from the Unmagnetized Ion Beam in a Hall Thruster," Applied Physics Letters, 102, 2, 023509 (2013).

Mikellides, I. G., and Katz, I., "Numerical Simulations of Hall-Effect Plasma Accelerators on a Magnetic-Field-Aligned Mesh," Physical Review E, 86, 4, 046703 (2012).

Chu, E., and Goebel, D.M., "High-Current Lanthanum Hexaboride Hollow Cathode for 10-to-50-kW Hall Thrusters," IEEE Transactions on Plasma Science, 40, 9, 2133-2144 (2012).

Polk, J.E., Goebel, D.M., Snyder, J.S., Schneider, A.C., Johnson, L.K., Sengupta, A., "A High Power Ion Thruster for Deep Space Missions," Review of Scientific Instruments 83, 7, 073306-073314 (2012).

Goebel, D. M., Jameson, K. K., and Hofer, R. R., "Hall Thruster Cathode Flow Impact on Coupling Voltage and Cathode Life," Journal of Propulsion and Power 28, 2, 355-363 (2012).

Snyder, J. S., Goebel, D. M., Hofer, R. R., Polk, J. E., Wallace, N. C., and Simpson, H., "Performance Evaluation of the T6 Ion Engine," Journal of Propulsion and Power 28, 2, 371-379 (2012).

Goebel, D. M., Polk, J. E., and Mikellides, I. G., "Ion Thruster Performance Impacts Due to Cathode Wear," Journal of Propulsion and Power 27, 4, 768-776 (2011).

Wirz R., Anderson J., Katz I., “Time-Dependent Erosion of Ion Optics,” Journal of Propulsion and Power, 27, 1, January–February 2011, DOI: 10.2514/1.46845.

Wirz R., Katz I., Goebel D., Anderson J., “Electron Backstreaming Determination for Ion Thrusters,” Journal of Propulsion and Power, 27, 1, January–February 2011, DOI: 10.2514/1.46844.

D.R. Bromaghim, G. D. Reed, J. T. Singleton, D. J. Connolly, L. K Johnson, D. G. Conroy, R. J. Gorecki, F.D. Tan, H. Choy, B. M. Pote, L. T. Byrne, W. J. Connolly, V. H. Hruby, J.K. Barbarits, P. F. Sydney, K. M. Hamada, R. A. Dressler, and Y.-H. Chiu, "Summary of On-Orbit Performance of the 200-W Hall Thruster System on TacSat-2," JANNAF J. Propulsion & Energetics 4, 87 (2011).

Katz, I., and Mikellides, I. G., "A “Quiet” Algorithm for the Simulation of Free Molecular Flow in Plasma Devices," Journal of Computational Physics, Vol. 230, No. 4, 2011, pp. 1454-1464.

Mikellides, I. G., Katz, I., Hofer, R. R., and Goebel, D. M., de Grys, K., and Mathers, A., "Magnetic Shielding of the Channel Walls in a Hall Plasma Accelerator," Physics of Plasmas, Vol. 18, No. 3, 2011, pp. 033501 (1-18).

J. T. Singleton, D. J. Connolly, D. R. Bromaghim, and L. K Johnson, "Flight Summary of Spacecraft-Thruster Interactions on TacSat-2," JANNAF J. Propulsion & Energetics 4, 103 (2011).

P. F. Sydney, K. M. Hamada, M. Bolden, T. M. Kelecy, D. T. Hall, D. A. Archambeault, R. A. Dressler, Y.-H. Chiu, D. R. Bromaghim, J. M. Ekholm, C. J. Finley, and L. K Johnson, "Ground-Based Observations of TacSat-2 Maneuvers," JANNAF J. Propulsion & Energetics4, 115 (2011).

Goebel, D. M. and Watkins, R. M., "Compact Lanthanum Hexaboride Hollow Cathode," Review of Scientific Instruments 81, 8, 083504 (2010).

Mikellides, I. G., Goebel, D. M., Snyder, J. S., Katz, I., and Herman, D. A., "The Discharge Plasma in Ion Engine Neutralizers: Numerical Simulations and Comparisons with Laboratory Data," Journal of Applied Physics, Vol. 108, No. 11, 2010, pp. 113308 (1-12).

Snyder, J. S., Anderson, J. R., Van Noord, J. L., and Soulas, G. C., "Environmental Testing of Nasa’s Evolutionary Xenon Thruster Prototype Model 1 Reworked Ion Engine," Journal of Propulsion and Power 25, 1, 94-104 (2009).

Shastry, R., Hofer, R. R., Reid, B. M., and Gallimore, A. D., "Method for Analyzing ExB Probe Spectra from Hall Thruster Plumes," Review of Scientific Instruments 80, 063502 (2009).

Sengupta, A., Goebel, D. M., and Owens, A. G., "Langmuir Probe Studies of Magnetic Confinement in an Ion Thruster Discharge Plasma," Journal of Propulsion and Power 25, 2, 387-396 (2009).

Sengupta, A., Anderson, J. A., Garner, C., Brophy, J. R., De Groh, K. K. et al., "Deep Space 1 Flight Spare Ion Thruster 30,000-Hour Life Test," Journal of Propulsion and Power 25, 1, 105-117 (2009).

Sengupta, A., "Magnetic Confinement in a Ring-Cusp Ion Thruster Discharge Plasma," Journal of Applied Physics 105, 9, 093303 (2009).

Polk, J. E., Mikellides, I. G., Katz, I., and Capece, A. M., "Tungsten and Barium Transport in the Internal Plasma of Hollow Cathodes," Journal of Applied Physics 105, 11, 113301 (2009).

Mikellides, I. G., "Effects of Viscosity in a Partially Ionized Channel Flow with Thermionic Emission," Physics of Plasmas 16, 1, 013501 (2009).

Brophy, J. R., Garner, C. E., and Mikes, S., "Dawn Ion Propulsion System: Initial Checkout after Launch," Journal of Propulsion and Power 25, 6, 1189-1202 (2009).

Wirz, R. E., Anderson, J. R., Goebel, D. M., and Katz, I., "Decel Grid Effects on Ion Thruster Grid Erosion," IEEE Transactions on Plasma Science 36, 5, 2122-2129 (2008).

Wirz, R., Sullivan, R., Przybylowski, J., and Silva, M., "Hollow Cathode and Low-Thrust Extraction Grid Analysis for a Miniature Ion Thruster," International Journal of Plasma Science and Engineering 2008, 1-12 (2008).

Wirz, R. and Goebel, D., "Effects of Magnetic Field Topography on Ion Thruster Discharge Performance," Plasma Sources Science and Technology 17, 3, 035010 (2008).

Sengupta, A., Kulleck, J., Hill, N., and Ohlinger, W., "Invited Article: Physical and Chemical Analyses of Impregnated Cathodes Operated in a Plasma Environment," Review of Scientific Instruments 79, 11, 111301 (2008).

Polk, J. E., Sekerak, M. J., Ziemer, J. K., Schein, J., Qi, N. et al., "A Theoretical Analysis of Vacuum Arc Thruster and Vacuum Arc Ion Thruster Performance," IEEE Transactions on Plasma Science 36, 5, 2167-2179 (2008).

Mikellides, I. G., Katz, I., Goebel, D. M., Jameson, K. K., and Polk, J. E., "Wear Mechanisms in Electron Sources for Ion Propulsion, 2: Discharge Hollow Cathode," Journal of Propulsion and Power 24, 4, 866 (2008).

Mikellides, I. G. and Katz, I., "Wear Mechanisms in Electron Sources for Ion Propulsion, 1: Neutralizer Hollow Cathode," Journal of Propulsion and Power 24, 4, 855 (2008).

Mandell, M. J., Davis, V. A., Pencil, E. J., Patterson, M. J., Mcewen, H. K. et al., "Modeling the NEXT Multithruster Array Test with Nascap-2k," IEEE Transactions on Plasma Science 36, 5, 2309-2318 (2008).

Kolasinski, R. D., Polk, J. E., Goebel, D. M., and Johnson, L. K., "Carbon Sputtering Yield Measurements at Grazing Incidence," Applied Surface Science 254, 2506-2515 (2008).

Katz, I., Mikellides, I. G., Goebel, D. M., and Polk, J. E., "Insert Heating and Ignition in Inert-Gas Hollow Cathodes," IEEE Transactions on Plasma Science 36, 5, 2199-2206 (2008).

Katz, I., Hofer, R. R., and Goebel, D. M., "Ion Current in Hall Thrusters," IEEE Transactions on Plasma Science 36, 5, 2015-2024 (2008).

Hofer, R. R., Johnson, L. K., Goebel, D. M., and Wirz, R. E., "Effects of Internally-Mounted Cathodes on Hall Thruster Plume Properties," IEEE Transactions on Plasma Science 36, 5, 2004-2014 (2008).

Goebel, D. M., "Analytical Discharge Model for RF Ion Thrusters," IEEE Transactions on Plasma Science 36, 5, 2111-2121 (2008).

Gamero-Castano, M., "Characterization of the Electrosprays of 1-Ethyl-3-Methylimidazolium Bis(Trifluoromethylsulfonyl) Imide in Vacuum," Physics of Fluids 20, 3, 032103 (2008).

Gamero-Castano, M., "The Structure of Electrospray Beams in Vacuum," Journal of Fluid Mechanics 604 (2008).

Corey, R.L., Snyder, J.S., Price, X., Malone, S.P., and T.M. Randolph, “Hall Thruster Plume Model for Spacecraft Impingement Torque: Development and Validation,” J. of Spacecraft and Rockets, vol. 45, no. 4, pps. 766-775, July-Aug. 2008.

Polk, J. E., Marrese-Reading, C. M., Thornber, B., Dang, L., Johnson, L. K. et al., "Scanning Optical Pyrometer for Measuring Temperatures in Hollow Cathodes," Review of Scientific Instruments 78, 093101 (2007).

Oh, D. Y., "Evaluation of Solar Electric Propulsion Technologies for Discovery-Class Missions," Journal of Spacecraft and Rockets 44, 2, 399-411 (2007).

Mikellides, I. G., Katz, I., Goebel, D. M., and Jameson, K. K., "Evidence of Nonclassical Plasma Transport in Hollow Cathodes for Electric Propulsion," Journal of Applied Physics 101, 063301 (2007).

Kolasinski, R. D., Polk, J. E., Goebel, D., and Johnson, L. K., "Sputtering Yield Measurements at Glancing Incidence Using a Quartz Crystal Microbalance," Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films 25, 2, 236 (2007).

Katz, I., Mikellides, I. G., Polk, J. E., Goebel, D. M., and Hornbeck, S. E., "Thermal Model of the Hollow Cathode Using Numerically Simulated Plasma Fluxes," Journal of Propulsion and Power 23, 3, 522 (2007).

Goebel, D. M., Watkins, R. M., and Jameson, K. K., "Lab6 Hollow Cathodes for Ion and Hall Thrusters," Journal of Propulsion and Power 23, 3, 552-558 (2007).

Goebel, D. M., Jameson, K. K., Katz, I., and Mikellides, I. G., "Potential Fluctuations and Energetic Ion Production in Hollow Cathode Discharges," Physics of Plasmas 14, 103508 (2007).

Gamero-Castano, M., "Induction Charge Detector with Multiple Sensing Stages," Review of Scientific Instruments 78, 4, 043301 (2007).

St. Rock, B., Blandino, J. J., Anderson, K. R., and Polk, J. E., "Thermal Analysis of a Lithium Vaporizer for a High-Power Magnetoplasmadynamic Thruster," Journal of Propulsion and Power 22, 5, 1098-1110 (2006).

Mikellides, I. G., Katz, I., Goebel, D. M., Polk, J. E., and Jameson, K. K., "Plasma Processes inside Dispenser Hollow Cathodes," Physics of Plasmas 13, 063504 (2006).

Mikellides, I. G., Katz, I., Kuharski, R. A., and Mandell, M. J., "Elastic Scattering of Ions in Electrostatic Thruster Plumes," Journal of Propulsion and Power 21, 1, 111 (2005).

Mikellides, I. G., Katz, I., Goebel, D. M., and Polk, J. E., "Hollow Cathode Theory and Experiment. Ii. A Two-Dimensional Theoretical Model of the Emitter Region," Journal of Applied Physics 98, 113303 (2005).

Goebel, D. M. and Schneider, A. C., "High-Voltage Breakdown and Conditioning of Carbon and Molybdenum Electrodes," IEEE Transactions on Plasma Science 33, 4, 1136-1148 (2005).

Goebel, D. M., Jameson, K. K., Watkins, R. M., Katz, I., and Mikellides, I. G., "Hollow Cathode Theory and Experiment. I. Plasma Characterization Using Fast Miniature Scanning Probes," Journal of Applied Physics 98, 113302 (2005).

Fernandez De La Mora, J., Thomson, B. A., and Gamero-Castano, M., "Tandem Mobility Mass Spectrometry Study of Electrosprayed Tetraheptyl Ammonium Bromide Clusters," Journal of the American Society for Mass Spectrometry 16, 717-732 (2005).

Kolasinski, R. D. and Polk, J. E., "Characterization of Cathode Keeper Wear by Surface Layer Activation," Journal of Propulsion and Power 20, 6, 992-999 (2004).

Wang, J., Polk, J., Brophy, J., and Katz, I., "Three-Dimensional Particle Simulations of Ion-Optics Plasma Flow and Grid Erosion," Journal of Propulsion and Power 19, 6, 1192-1199 (2003).

Parks, D. E. and Katz, I., "Asymptotic Magnetic Field Expansion in Mini-Magnetospheric Plasma Propulsion," Journal of Spacecraft and Rockets 40, 4, 597-598 (2003).

Mikellides, I. G., Mandell, M. J., and Katz, I., "Stagnation-Point Density of Hypersonic Ions in a Repelling Plasma Sheath," Journal of Spacecraft 40, 2, 298-301 (2003).

Katz, I., Anderson, J. R., Polk, J. E., and Brophy, J. R., "One-Dimensional Hollow Cathode Model," Journal of Propulsion and Power 19, 4, 595-600 (2003).

Goebel, D. M., Schneider, A. C., Menninger, W. L., and Weekley, J. M., "Gain Increases through End of Life in Traveling Wave Tubes," IEEE Transactions on Plasma Science 50, 4, 1117-1124 (2003).

Frisbee, R. H., "Advanced Space Propulsion for the 21st Century," Journal of Propulsion and Power 19, 6, 1129-1154 (2003).

Brophy, J., "Advanced Ion Propulsion Systems for Affordable Deep-Space Missions," Acta Astronautica 52, 309-316 (2003).

Schein, J., Qi, N., Binder, R., Krishnan, M., Ziemer, J. K. et al., "Inductive Energy Storage Driven Vacuum Arc Thruster," Review of Scientific Instruments 73, 2, 925 (2002).

Rayman, M. D. and Williams, S. N., "Design of the First Interplanetary Solar Electric Propulsion Mission," Journal of Spacecraft and Rockets 39, 4, 589-595 (2002).

Mikellides, I. G., Jongeward, G. A., Katz, I., and Manzella, D. M., "Plume Modeling of Stationary Plasma Thrusters and Interactions with the Express-a Spacecraft," Journal of Spacecraft and Rockets 39, 6, 894-903 (2002).

Brophy, J. R., "Nasa’s Deep Space 1 Ion Engine (Plenary)," Review of Scientific Instruments 73, 2, 1071 (2002).

Marcucci, M. G. and Polk, J. E., "Nstar Xenon Ion Thruster on Deep Space 1: Ground and Flight Tests (Invited)," Review of Scientific Instruments 71, 3, 1389-1400 (2000).

Ganapathi, G. B. and Engelbrecht, C. S., "Performance of the Xenon Feed System on Deep Space One," Journal of Spacecraft and Rockets 37, 3, 392-398 (2000).

Brophy, J. R. and Noca, M., "Electric Propulsion for Solar System Exploration," Journal of Propulsion and Power 14, 5, 700-707 (1998).

Erwin, D. A., Pham-Van-Diep, G. C., and Deininger, W. D., "Laser-Induced Fluorescence Measurements of Flow Velocity in High-Power Arcjet Thruster Plumes," AIAA Journal 29, 8, 1298-1303 (1991).

Deininger, W. D., Pivirotto, T. J., and Brophy, J. R., "Effect of Nozzle and Cathode Configuration on Arcjet Performance," Journal of Propulsion 6, 3, 271-275 (1990).

Brophy, J. R., "Computer-Controlled Xenon Ion Engine Operation," Journal of Propulsion 5, 1, 42-48 (1989).

Brophy, J. R. and Wilbur, P. J., "Simple Performance Model for Ring and Line Cusp Ion Thrusters " AIAA Journal 23, 11, 1731-1736 (1985).