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Journal Publications

In Review:

  1. Chhavi, Mitchell L. R. Walker, "Azimuthal Magnetic Field Gradient Effects on Hall Effect Thruster Performance and Stability," Journal of Propulsion and Power, In Review - October 2024.
  2. Chhavi, Mitchell L. R. Walker, "Characterization of the Ion Beam and Thrust Vector of a 5-kW Hall Effect Thruster with a Hemispherical Sweep Probe Apparatus," Journal of Electric Propulsion, In Review - October 2024
  3. William Brabston, Dan Lev, Mitchell L. R. Walker, "Hall Thruster Performance and Efficiency Analysis of a Molecular Propellant," Journal of Propulsion and Power, In Review - May 2024.
  4. David R. Jovel, Janice Cabrera, Mitchell L. R. Walker, "Current Pathways Model for Hall Thruster Plumes in Ground-based Vacuum Test Facilities," Journal of Electric Propulsion, In Review - January 2024.

 

Accepted:

  1. David R. Jovel, Janice Cabrera, Mitchell L. R. Walker, "Hall Effect Thruster Impedance Characterization in Ground-based Vacuum Test Facilities," Journal of Electric Propulsion, Accepted - October 2024.
  2. Igor Levchenko, Dan Goebel, Daniela Pedrini, Riccardo Albertoni, Oleg Baranov, Igal Kronhaus, Dan Lev, Mitchell L. R. Walker, Shuyan Xu, Kateryna Bazaka, "Recent Innovations to Advance Space Propulsion Technologies," Progress in Aerospace Sciences, Accepted - March 2023.

 

Published:

  1. Jean Luis Suazo Betancourt, Naia Butler-Craig, Julian Lopez-Uricoechea, Adam Steinberg, Mitchell L. R. Walker, "Thomson Scattering Measurements Indicate Non-Isothermal Magnetic Field Lines in Magnetically-Shielded Hall Effect Thrusters," Physics of Plasmas, Volume 31, No. 11, November 2024.
  2. Jean Luis Suazo Betancourt, Julian Lopez-Uricoechea, Naia Butler-Craig, Adam Steinberg, Mitchell L. R. Walker, "Bayesian-inverted Laser Thomson Scattering Measurements Indicate Electrostatic Erosion Pathways in Magnetically-Shielded Hall Effect Thrusters," Journal of Applied Physics, Volume 136, No. 12, September 2024.
  3. Julian Lopez-Uricoechea, Jean Luis Suazo Betancourt, Naia Butler-Craig, Mitchell L. R. Walker, "Spatially-Resolved Thomson Scattering Measurements of Electron Properties Across the Acceleration Region of a High-Power Magnetically-Shielded Hall Effect Thruster," Journal of Applied Physics, Vol 136, September 2024, pp. 113303.
  4. Chhavi Chhavi, Mitchell L. R. Walker, "Review of Non-conventional Hall Effect Thrusters," Journal of Electric Propulsion, Vol. 3, No. 11, June 2024.
  5. Dongho Lee, William Brabston, Dan Lev, Mitchell L. R. Walker, "Argon Admixture-driven Enhanced Ionization and Performance of a 5-kW Hall Thruster on Krypton," Journal of Physics D:  Applied Physics, Volume 57, May 2024, pp. 325201.
  6. Jean Luis Suazo Betancort, Julian Lopez-Uricoechea, Naia Butler-Craig, Adam Steinberg, Mitchell L. R. Walker, "An Incoherent Thomson Scattering System for Measurements Near Plasma Boundaries,", Review of Scientific Instruments, Vol. 95, No. 4, April 2024, pp. 043001.
  7. Jean Luis Suazo Betancourt, Samuel Grauer, Junhwi Bak, Adam Steinberg, Mitchell Walker, "Bayesian Model Selection For Thomson Scattering," Review of Scientific Instruments, Vol. 95, No. 4, April 2024, pp. 043004.
  8. Julian Lopez-Uricoechea, Jean Luis Suazo Betancourt, Naia Butler-Craig, Mitchell L. R. Walker, "Spatially-Resolved Laser Thomson Scattering Measurements in a Negative Glow and Cathode Presheath to Investigate a 1-D Sheath Model," Physics of Plasma, Vol. 31, No. 3, March 2024, pp. 033503.
  9. Jean Luis Suazo Betancourt, Naia Butler-Craig, Julian Lopez-Uricoechea, Junhwi Bak, Dongho Lee, Adam M. Steinberg, Mitchell L. R. Walker, "Thomson Scattering Measurements in the Krypton Plume of a Lanthanum Hexaboride Hollow Cathode in a Large Vacuum Test Facility," Journal of Applied Physics, Volume 135, No. 8, February 2024. pp. 083302.
  10. Dongho Lee, Jean Luis Suazo Betancourt, Dan Lev, Mitchell L. R. Walker, "Nitrogen Admixture-driven Electron Cooling and Plasma Bullet Dynamics in Atmospheric-pressure DC Nanosecond-pulsed Argon Jet Plasmas," Journal of Applied Physics, Volume 135, No. 6, February 2024. pp. 064404.
  11. Junhwi Bak, Jean Luis Suazo Betancourt, Anuj Rekhy, Amirhossein Abbasszadehrad, Richard B. Miles, Christopher M. Limbach, Mitchell L. R. Walker, "High-Resolution Spatially Extended 1D Laser Scattering Diagnostics using Volume Bragg Grating Notch Filters," Review of Scientific Instruments, Volume 94, February 2023, pp. 023003.
  12. Jonathan Walker, Dan Lev, Mitchell Walker, "Electrical Characteristics of a Hall Effect Thruster Body in a Vacuum Facility Testing Environment," Journal of Electric Propulsion, Volume 1, Article 18, October 2022.
  13. Julian Lopez-Uricoechea, Dan Lev, Mitchell Walker, "0-D Composition and Performance Analysis of an Air-Breathing RF Ion Thruster," Journal of Electric Propulsion, Volume 1, Article 11, September 2022.
  14. David Jovel, Dan Herman, Mitchell Walker, "Review of High-Power Electrothermal and Electrostatic Electric Propulsion," Journal of Propulsion of Power, Volume 38, Number 6, November-December 2022, pp. 1051-1081.
  15. Nathan P. Brown, Muhannad Eladl, Adam M. Steinberg, Jason Deibel, Mitchell Walker, "Noninvasive THz-TDS Measurements of Plasma Bounded and Optically Shielded by Hall Thruster Wall Material," Plasma Sources Science and Technology, Volume 30, July 2021, pp. 075027.
  16. Nathan P. Brown, Sam J. Grauer, Adam M. Steinberg, Jason A. Deibel, Mitchell Walker., "Bayesian Framework for THz-TDS Plasma Diagnostics," Optics Express, Volume 29, Number 4, February 2021, pp. 4887-4901.
  17. Sara Miller, Mitchell Walker, J. Agolli, John Dankanich, "Survey and Performance Evaluation of Small Satellite Propulsion Technologies," Journal of Spacecraft and Rockets, Volume 58, Number 1, January-February 2021, pp. 222-231.
  18. Nathan P. Brown, Collin B. Whittaker, Julian J. Rimoli, W. Jud Ready, Mitchell Walker, "Formation and Impact of Microcracks in Plasma Erosion of M26 Boron Nitride," Journal of Propulsion and Power, Volume 37, Number 1, January-February 2021, pp. 59-67.
  19. Nathan P. Brown, Mitchell Walker, "Review of Plasma-Induced Hall Thruster Erosion," Applied Sciences, Vol. 10, doi: 10.3390/app1013775, May 2020.
  20. Jason D. Frieman, Thomas M. Liu, Mitchell Walker, "Background Flow Model Validation with a 6-kW Hall Effect Thruster," Journal of Propulsion of Power, Volume 36, Number 2, March-April 2020, pp. 308-311.
  21. Connie Liu, Mitchell Walker, Morris Cohen, "Time-resolved Measurements of Plasma Parameters for Nanosecond-pulsed Argon Plasmas," IEEE Transaction on Plasma Science, Vol. 48, No. 4, April 2020, pp. 1060-1075.
  22. Graham P. Sanborn, Lake A. Singh, Stephan P. Turano, Shanmurugan Selvamurugan, Mitchell Walker, W. Jud Ready, "Field Emission Damage Modes of Carbon Nanotube Spindt Cathode Arrays," The Journal of The Minerals, Metals & Materials Society, Volume 72, Issue 1, January 2020, pp. 544-551.
  23. Parker Singletary, Morris Cohen, Mitchell Walker, Connie Liu, Cheong Chan, “Optical Analysis of Nanosecond-lifetime Plasma Parameters,” IEEE Transactions on Plasma Science, Vol. 48, Issue 1, January 2020, pp. 179-188.
  24. Irina Schweigert, Mitchell Walker, Michael Keidar, "Genesis of Non-Uniformity of Plasma Fluxes Over Emissive Wall in Low-Temperature Plasmas," Plasma Research Express, Volume 1, Number 4, December 2019.
  25. Natalie R. S. Caruso, Mitchell Walker, “Effects of Ingested versus Injected Propellant on Radio-Frequency Discharge Plasma Properties,” Frontiers in Physics, Volume 6, Article 161, January 2019.
  26. Ho Young Kim, Mark Golkowski, Czeslaw Golkowski, Peter Stoltz, Morris Cohen, Mitchell Walker, “PIC Simulations of Post-pulse Field Reversal and Secondary Ionization in Nanosecond Pulsed Argon Discharges,” Plasma Sources Science and Technology, Volume 27, Number 5, May 2018, pp. 055011 1-10.
  27. Jason D. Frieman, Nathan P. Brown, Connie Liu, Thomas M. Liu, Mitchell Walker, Vadim Khayms, David Q. King, “Impact of Propellant Species on Hall Effect Thruster Electrical Facility Effects,” Journal of Propulsion and Power, Volume 34, Number 3, May-June, 2018.
  28. Irina Schweigert, Thomas Burton, Gregory Thompson, Samuel J. Langendorf, Mitchell Walker, Michael Keidar, “Plasma Interaction with Emissive Surface with Debye-Scale Grooves,” Plasma Sources Science and Technology, Volume 27, Issue 4, April 2018, pp. 045004.
  29. Rodney Averett, Tyler Scogin, Mitchell Walker, “Electromagnetically Induced Distortion of a Fibrin Matrix with Embedded Microparticles,” Journal of Mechanics in Medicine and Biology, Volume 18, Number 2, March 2018.
  30. Igor Levchenko, Su-Yang Xu, George Teel, Davide Mariotti, Mitchell Walker, Michael Keidar, “Nano in Space: Big Expectations from Advanced Nanoscaled Materials,” Nature Communications, Volume 9, 879, 2018.  DOI:  10.1038/s41467-017-02269-7. 
  31. Jason D. Frieman, Nathan P. Brown, Connie Liu, Thomas M. Liu, Mitchell Walker, Vadim Khayms, David Q. King, “Electrical Facility Effects on Faraday Probe Measurements,” Journal of Propulsion and Power, Volume 34, Number 1, January-February 2018, pp. 267-269.
  32. Natalie Caruso, Mitchell Walker, “Neutral Particle Ingestion Effects on Helicon Ion Thruster Plasma Plume Properties,” Journal of Propulsion and Power, Volume 34, Number 1, January-February 2018, pp. 58-65.
  33. Jason D. Frieman, Thomas M. Liu, Mitchell Walker, “Background Flow Model of Hall Thruster Neutral Ingestion,” Journal of Propulsion and Power, September-October 2017, pp. 1087-1101.
  34. Joseph H. Saleh, Fan Geng, Michelle Ku, Mitchell Walker, “Electric Propulsion Reliability:  Statistical Analysis of On-orbit Anomalies and Comparative Analysis of Electric versus Chemical Propulsion Failure Rates,” Acta Astronautica, (139) July 2017, pp. 141-156.
  35. Jay Polk, Anthony Pancotti, Thomas Haag, Scott King, Mitchell Walker, Joseph Blakely, John Ziemer, “Recommended Practices for Thrust Measurement in Electric Propulsion,” Journal of Propulsion and Power, Volume 33, Number 3, May-June 2017, pp. 539-555.
  36. Daniel Brown, Mitchell Walker, James Szabo, Wensheng Huang, “Faraday Probes for Solar Electric Propulsion: Guidelines and Recommended Practices,” Journal of Propulsion and Power, Volume 33, Number 3, May-June 2017, pp. 582-613.
  37. John Dankanich, Mitchell Walker, Michael Swiatek, John Yim, “Recommended Practice for Pressure Measurements and Calculation of Effective Pumping Speeds during Electric Propulsion Testing,” Journal of Propulsion and Power, Volume 33, Number 3, May-June 2017, pp. 668-680.
  38. Steve Snyder, Jason Frieman, Mitchell Walker, “Flow Control and Measurement in Electric Propulsion Systems,” Journal of Propulsion and Power, Volume 33, Number 3, May-June 2017, pp. 5556-564.
  39. Aaron Schinder, Julian Rimoli, Mitchell Walker, “Investigation of Plasma Material Erosion Under Mechanical Stress,” Journal of Propulsion and Power, Volume 33, Number 2, March-April 2017, pp. 433-447.
  40. Jonathan A. Walker, Langendorf, S. J., Mitchell Walker, “Electrical Facility Effects on Hall Current Thrusters: Electron Termination Pathway Manipulation,” Journal of Propulsion and Power, Volume 32, Number 6, November-December 2016, pp. 1365-1377.
  41. Jonathan A. Walker, Jason D. Frieman, Vadim Khayms, Peter Y. Peterson, David Q. King, Mitchell Walker, “Electrical Facility Effects on Hall Effect Thruster Cathode Coupling: Discharge Oscillations and Facility Coupling,” Journal of Propulsion and Power, Volume 32, Number 4, July-August 2016, pp. 844-855.
  42. Samuel J. Langendorf, Mitchell Walker, "Hysteresis and Mode Transitions in Plasma Sheath Collapse Due to Secondary Electron Emission," Journal of Applied Physics, Volume 119, March 2016, pp. 113305 1-5.
  43. Jason D. Frieman, Jonathan A. Walker, Vadim Khayms, David Q. King, Mitchell Walker, “Electrical Facility Effects on Hall Effect Thruster Cathode Coupling – Performance and Plume Properties,” Journal of Propulsion and Power, Volume 32, Number 1, January-February 2016, pp. 251-264.
  44. Jonathan A. Walker, Sam Langendorf, Mitchell Walker, Kurt Polzin, Adam Kimberlin, “Velocimetry of Cathode Particles in a Magnetoplasmadynamic Thruster Discharge Plasma,” Review of Scientific Instruments, Volume 86, Number 7, July 2015, pp. 073513 1-10.
  45. Logan T. Williams., Mitchell Walker, “Plume Structure and Ion Acceleration of a Helicon Plasma Source,” IEEE Transactions on Plasma Science, Volume 43, Number 5, May 2015, pp. 1694-1705.
  46. Lake Singh, Mitchell Walker, “A Review of Research in Low Earth Orbit Propellant Collection,” Progress in Aerospace Sciences, Volume 75, April 2015, Pages 15-25.
  47. Samuel J. Langendorf, Mitchell Walker, “Effect of Secondary Electron Emission on the Plasma Sheath,” Physics of Plasmas, March 2015, Vol. 22, 033515 (2015).
  48. Samuel J. Langendorf, Kunning Xu, Mitchell Walker, “Effects of wall electrodes on Hall effect thruster plasma,” Physics of Plasmas, February 2015, Vol. 22, No 2, 023508.
  49. Irina Schweigert, Samuel J. Langendorf, Mitchell Walker, Michael Keidar, “Sheath structure transition controlled by secondary electron emission,” Plasma Sources Science and Technology, February 2015, Vol. 24, No. 2, 025012.
  50. Lake Singh, Graham Sanborn, Stephan Turano, Mitchell Walker, Jud Ready, “Operation of a Carbon Nanotube Field Emitter Array in a Hall Effect Thruster Plume Environment,” IEEE Transactions on Plasma Science Special Issue - Plasma Propulsion, Volume 43, Issue 1, January 2015. pp. 95-102.
  51. Jason Frieman, Scott King, Mitchell Walker, Vadim Khayms, David Q. King, “Role of a Conducting Chamber in the Hall Effect Thruster Electrical Circuit,” Journal of Propulsion and Power, Volume 30, Number 6, November-December 2014, pp. 1471-1479.
  52. Aaron Schinder, Mitchell Walker, Julian Rimoli, “3D Model for Erosion of a Hall Effect Thruster Discharge Channel Wall,” Journal of Propulsion and Power, Volume 30, Number 5, September-October 2014, pg. 1373-1382.
  53. Kybeom Kwon, Mitchell Walker, Dimitri N. Mavris, “Study on Anomalous Electron Diffusion in the Hall Effect Thruster,” International Journal of Aeronautical & Space Sciences, Volume 15, Number 3, September 2014, pp. 320-334.
  54. Scott King, Mitchell Walker, Silvio Chianese, “Atmospheric Electric Propulsion Mission Performance Tool,” Journal of Spacecraft and Rockets, May-June 2014, Volume 51, Issue 3, pp. 931-937.
  55. Logan Williams, Mitchell Walker, “Initial Performance Evaluation of a Gridded Radio Frequency Ion Thruster,” Journal of Propulsion and Power, Volume 30, Number 3, May-June 2014, pp. 645-655.
  56. Thomas Burton, Aaron Schinder, German Capuano, Julian Rimoli, Mitchell Walker, Gregory Thompson, “Plasma-Induced Erosion on Ceramic Wall Structures in Hall-Effect Thrusters,” Journal of Propulsion and Power, Volume 30, Number 3, May-June, 2014, pp. 690-695.
  57. Kunning Xu, Mitchell Walker, "Effect of External Cathode Azimuthal Position on Hall Effect Thruster Plume," Journal of Propulsion and Power, Vol. 30, No. 2, March–April 2014.
  58. Rafael Martinez, Hoang Dao, Mitchell Walker, “Power Deposition into the Discharge Channel of a Hall Effect Thruster,” Journal of Propulsion and Power, Vol. 30, No. 1, January–February 2014, pp. 209-220.
  59. Logan Williams, Mitchell Walker, “Ion Production Cost of a Gridded Helicon Ion Thruster,” Plasma Sources Science and Technology, Volume 22, Number 5, October 2013, pp. 055019.
  60. Lake Singh, Mitchell Walker, “Charge Exchange Interactions on Near-Earth Proton Radiation for Orbit Perturbation of High Area-to-Mass Ratio Objects,” Advances in Space Research, Volume 52, Issue 3, 1 August 2013, pp. 496–504.
  61. Sebastiano Giannelli, Alexander Kieckhafer, Mitchell Walker, "Neutral Gas Expansion in a Cylindrical Helicon Discharge Chamber," Journal of Propulsion and Power, Vol. 29, No. 3, May–June 2013, pp. 540-546.
  62. Logan Williams, Mitchell Walker, “Thrust Measurements of a RF Plasma Source," Journal of Propulsion and Power, Vol. 29, No. 3, May–June 2013, pp. 520-527.
  63. Rafael Martinez, Mitchell Walker, “Propellant Thermal Management Effect on Neutral Residence Time in Low-Voltage Hall Thrusters,” Journal of Propulsion and Power, Vol. 29, No. 3, May–June 2013, pp. 528-539.
  64. Samuel Langendorf, Mitchell Walker, “Characterization of Hall Effect Thruster Propellant Distributors with Flame Visualization,” Review of Scientific Instruments, Volume 84, Number 1, January 2013, pp. 013302 1-7.
  65. Mitchell Walker, Ryan Russell, Lake Singh, “Utilization of Residual Helium to Extend Satellite Lifetimes and Mitigate Space Debris," Journal of Propulsion and Power, Volume 28, Number 6, November–December 2012, pp. 1406-1412.
  66. Kunning Xu, Hoang Dao, Mitchell Walker, "Potential Contour Shaping and Sheath Behavior with Wall Electrodes and Near-Wall Magnetic Fields in a Hall Thruster," Phys. Plasmas Volume 19, Number 10, October 2012, pp. 103502 1-6.
  67. Kunning Xu, Mitchell Walker, “Plume Characterization of an Ion Focusing Hall Thruster,” Journal of Propulsion and Power, Volume 28, Number 5, September-October, 2012, pp. 1105-1115.
  68. Kybeom Kwon, Mitchell Walker, Dmitri Mavris, “Self-Consistent, One-dimensional Analysis of the Hall Effect Thruster,” Plasma Sources Science and Technology, Volume 20, Number 4, July 2011, pp. 045021 1-15.
  69. Kunning Xu, Mitchell Walker, “Technique to Collimate Ions in a Hall Effect Thruster Discharge Chamber,” Journal of Propulsion and Power, Volume 27, Number 3, May-June 2011, pp. 564-572.
  70. Carl Book, Mitchell Walker, “Effect of Anode Temperature on Hall Effect Thruster Performance,” Journal of Propulsion and Power, Volume 26, Number 5, September-October 2010, pp. 1036-1044.
  71. Logan Williams, Mitchell Walker, Victor Kumsomboone, Jud Ready, “Lifetime and Failure Mechanisms of an Arrayed Carbon Nanotube Field Emission Cathode,” IEEE Transactions on Electron Devices, Volume 57, No. 11, August 2010, pp. 3163-3168.
  72. Alexander Kieckhafer, Mitchell Walker, “RF Power System for Thrust Measurements of a Helicon Plasma Source,” Review of Scientific Instruments, Volume 81, Issue 7, July 2010, pp. 075106 1-8.
  73. Doug Palmer, Mitchell Walker, "Operation of an Annular Helicon Plasma Source," Journal of Propulsion and Power, Volume 25, Number 5, September-October 2009, pp. 1013-1019.
  74. Kunning Xu, Mitchell Walker, “High-Power, Null-Type, Inverted Pendulum Thrust Stand,” Review of Scientific Instruments, Volume 80, Number 5, May 2009, pp. 055103 1-6.
  75. Mitchell Walker, Alec Gallimore, “Hall Thruster Cluster Operation with a Shared Cathode,” Journal of Propulsion and Power, Volume 23, Number 3, May–June 2007, pp. 528-536.
  76. Masayuki Yano, Mitchell Walker, “Generalized Theory of Annularly-Bounded Helicon Waves,” Physics of Plasmas, Volume 14, Number 3, March 2007, pp. 033510 1-7.
  77. Mitchell Walker, Alec Gallimore, “Performance Characteristics of a Cluster of 5-kW Laboratory Hall Thrusters,” Journal of Propulsion and Power, Volume 23, Number 1, January-February 2007, pp. 35-43.
  78. Masayuki Yano, Mitchell Walker, “Plasma Ionization by Annularly-Bounded Helicon Waves,” Physics of Plasma, Volume 13, Number 6, June 2006, pp. 063501 1-5.
  79. Mitchell Walker, Richard Hofer, Alec Gallimore, "Ion Collection in Hall Thruster Plumes," Journal of Propulsion and Power, Volume 22, Number 1, January-February 2006, pp. 205-209.
  80. Joshua Rovey, Mitchell Walker, Peter Peterson, Alec Gallimore, “A Magnetically-Filtered Faraday Probe for Measuring the Ion Current Density Profile of a Hall Thruster,” Review of Scientific Instruments, Volume 77, Number 1, January 2006, pp. 013503 1-8.
  81. Mitchell Walker, Alan Victor, Richard Hofer, Alec Gallimore, "Effect of Backpressure on Ion Current Density Measurements in Hall Thruster Plumes," Journal of Propulsion and Power, Volume 21, Number 3, May-June 2005, pp. 408-415.
  82. Mitchell Walker, Alec Gallimore, "Neutral Density Map of Hall Thruster Plume Expansion in a Vacuum Chamber," Review of Scientific Instruments, Volume 76, Number 5, May 2005, pp. 053509 1-10.
  83. Mitchell Walker, Alec Gallimore, Chunpei Cai, Ian Boyd, "Vacuum Chamber Pressure Maps of a Hall Thruster Cold Flow Expansion," Journal of Propulsion and Power, Volume 20, Number 6, November–December 2004, pp. 1127-1131.
  84. Ian Boyd, Chunpei Cai, Mitchell Walker, Alec Gallimore, “Computation of Neutral Gas Flow of a Hall Thruster into a Vacuum Chamber,” Peer-reviewed Proceedings of the 23rd International Conference on Rarefied Gas Dynamics, Whistler, BC, Canada, Aug. 2002, 123-133.

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Conference Papers

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  1. Adrian Vicente La Lande, Dan Lev, Mitchell L. R. Walker, Nathan Rosenblad, Michael Holmes, "Characterization and Far-field Plume Analysis on the HET-X Hall Effect Thruster," Small Satellite Conference, Logan, Utah, August 3-8, 2024.
  2. Dongho Lee, William P. Brabston, Dan Lev, Mitchell L. R. Walker, "Exploration of the Performance and Ion Beam Properties of a 5-kW Hall Thruster Operating on Kr-Ar Mixtures," IEPC-2024-188, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  3. Chhavi, Mitchell L. R. Walker, "3-Dimensional Characterization of Ion Beam Current using a Hemispherical Sweep Apparatus," IEPC-2024-199, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  4. William P. Brabston, Luke A. Marino, Dan R. Lev, Mitchell L. R. Walker, "Analysis of the Ionization and Acceleration Efficiencies of Molecular Nitrogen in a Hall Effect Thruster,"  IEPC-2024-297, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  5. William P. Brabston, Luke A. Marino, Dan R. Lev, Mitchell L. R. Walker, "Design and Testing of a Multimode and In-Situ Propellant Feed System," IEPC-2024-302, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  6. Muhannad M. Eladl, Mitchell L. R. Walker, "Characterizing Bounded Plasmas using THz Time Domain Spectroscopy," IEPC-2024-360, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  7. Austen J. Thomas, Kristina Lemmer, Janice Cabrera, Mitchell L. R. Walker, Tyler Topham, John Foster, "High-Speed Far-Field Energy Measurements in a 9-kW Hall Effect Thruster for Model Inference and Calibration," IEPC-2024-459, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  8. Julian Lopez-Uricoechea, Jean Luis Suazo Betancourt, Naia Butler-Craig, Mitchell L. R. Walker, "Laser Thomson Scattering Measurements and Inference of the Electron Hall Parameter Across the Acceleration Region of a Hall Effect Thruster," IEPC-2024-509, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  9. Ajay Krishnan, Dan R. Lev, Maryam Saeedifard, Lukas Graber, Mitchell L. R. Walker, "Impedance Analysis of a Hall Thruster Discharge Circuit and Plasma Load to Address Harness Facility Effects," IEPC-2024-619, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  10. Janice D. Cabrera, David R. Jovel, Mitchell L.R. Walker, "Pressure Facility Effects on the Impedance Characteristics of a 9-kW HET," IEPC-2024-808, 38th International Electric Propulsion Conference, Toulouse, France, June 23-28, 2024.
  11. David R. Jovel, Mitchell Walker, "Current Pathways Model for Hall Thruster Plumes in Ground-based Vacuum Test Facilities," AIAA-2024-2365, 2024 SciTech, Orlando, GL, January 8012, 2024. 
  12. Mitchell Walker, Dan Lev, Benjamin Jorns, John Foster, Alec Gallimore, Alex Gorodetsky, Joshua Rovey, Huck Beng Chew, Deborah Levin, John Williams, Azer Yalin, Richie Wirz, Jaime Marian, Iain Boyd, Kentaro Hara, Kristina Lemmer, "Overview of the Joint AdvaNced PropUlsion InStitute (JANUS)," IEPC-2022-156, 37th International Electric Propulsion Conference, Boston, Massachusetts, June 19-23, 2022.
  13. Wirz, R., Walker, M. L. R., et al., "Predictive Engineering Modeling for Life and Performance Assessment of Electric Propulsion Systems," IEPC-2022-410, 37th International Electric Propulsion Conference, Boston, Massachusetts, June 19-23, 2022.
  14. Nathan P. Brown, Adam M. Steinberg, Jason A. Deibel, Mitchell Walker, "Assessment of the Capability of Terahertz Time-domain Spectroscopy as a Plasma Diagnostic,"  AIAA Propulsion and Energy Forum, Virtual Event, August 24-28, 2020.
  15. Nathan P. Brown, Mitchell Walker, "Terahertz Time-Domain Spectroscopy as an Electric Propulsion Diagnostic," IEPC-2019-408, 36th International Electric Propulsion Conference, Vienna, Austria, September 15-20, 2019.
  16. Irina Schweigert, Thomas S. Burton, Gregory B. Thompson, Samuel Langendorf, Mitchell Walker, Michael Keidar, “Transition in Sheath Structure Near Emissive Grooved Surface in Discharge Plasma Controlled by Electron Beam,” 70th Annual Gaseous Electronics Conference, Pittsburgh, Pennsylvania, November 6-10, 2017.
  17. Alexander L. Bogorad, Kevin August, Daniel Lichtin, John Pytel, Kevin Payne, Romain Herschitz, Su Chad, Larry Capots, Barry Noakes, Ryan Dubisher, Mitchell Walker, Eugina D. Mendez Ramos, Jonathan A. Walker, Nathan Prestridge, “Interaction of Spacecraft Arcjet Power Subsystem with Combined On orbit Environments and Electric Propulsion Plume: Ground Test Results,” IEPC-2017-225, 35th International Electric Propulsion Conference, Atlanta, Georgia, October 8-12, 2017.
  18. Jason D. Frieman, Thomas M. Liu, Mitchell Walker, “Development of Background Flow Model of Hall Thruster Neutral Ingestion,” IEPC-2017-008, 35th International Electric Propulsion Conference, Atlanta, Georgia, October 8-12, 2017.
  19. David R. Jovel, Brandon A. Sforzo, Kristopher L. Manion, Nathan P. Brown, Xingjian Wang, David J. Wu, Mitchell Walker, Vigor Yang, “Research Capabilities in Propulsion and Combustion Science at the Georgia Institute of Technology,” AIAA/SAE/ASEE 53rd Joint Propulsion Conference, Atlanta, GA, July 10-12, 2017.
  20. Morris B. Cohen, Lee Thompson, Nate Opalinski, Parker Singletary, Mitchel Walker, Cheong Chan, Mark Golkowski, “Broadband Electrically Short Transmitters via Hi-Speed Time-Varying Antenna Properties,” 2017 IEEE AP-S Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, San Diego, CA, July 9-14, 2017.
  21. Jason D. Frieman, Nathan P. Brown, Connie Y. Liu, Thomas M. Liu, Mitchell Walker, Vadim Khayms, David Q. King, “Electrical Facility Effects on the Operation of a Low-Power Hall Effect Thruster,” JANNAF Propulsion Meeting, Phoenix, AZ, December 5-8, 2016.
  22. Jason D. Frieman, Nathan P. Brown, Connie Y. Liu, Thomas M. Liu, Mitchell Walker, Vadim Khayms, David Q. King, “Impact of Propellant Selection on Hall Effect Thruster Electrical Facility Effects,” JANNAF Propulsion Meeting, Phoenix, AZ, December 5-8, 2016.
  23. Jason D. Frieman, Thomas M. Liu, Mitchell Walker, Jason Makela, Alex Mathers, Peter Y. Peterson, “Performance Evaluation of the T-40 Low-Power Hall Current Thruster,” AIAA/SAE/ASEE 52nd Joint Propulsion Conference and Exhibit, Salt Lake City, Utah, July 25-27, 2016.
  24. Aaron M. Schinder, Julian J. Rimoli, Mitchell Walker, “Plasma Erosion of Stressed Fused Silica and M26 Borosil,” AIAA/SAE/ASEE 52nd Joint Propulsion Conference and Exhibit, Salt Lake City, Utah, July 25-27, 2016.
  25. Irina Schweigert, Samuel Langendorf, Mitchell Walker, Michael Keidar, “Plasma-Wall Interaction Controlled by Secondary Electron Emission,” IEPC-2015-343, 34th International Electric Propulsion Conference, Kobe-Hyogo, Japan, July 4-10, 2015.
  26. C-S. Park, Mitchell Walker, S-O. Kim, “Flexible microplasma thrusters using jet-to-jet coupling effect”, The 8th International Workshop on Microplasmas (IWM 2015), Seton Hall University, Newark, NJ, May 11 – 15, 2015.
  27. Natalie Schloeder, Tyler Scogin, Thomas Liu, Mitchell Walker, Kurt Polzin, John Dankanich, Anne Aanesland, “Initial Thrust Measurements of Marshall’s Ion-Ion Thruster,” 51st Joint Propulsion Conference and Exhibit, Orlando, FL, July 27-29, 2015.
  28. Jonathan Walker, Samuel Langendorf, Mitchell Walker, Vadim Khayms, “Electrical Facility Effects on Hall Effect Thrusters: Electron Termination Pathway Manipulation through the Bias of a Downstream Electrode,” 62nd JANNAF Propulsion Meeting, Nashville, TN, June 1-15, 2015.
  29. Irina Schweigert, Samuel Langendorf, Michael Keidar, Mitchell Walker, “Sheath Structure Transition Controlled by Secondary Electron Emission at Low Gas Pressure,” 67th Annual Gaseous Electronics Conference, Raleigh, NC, November 2-7, 2014.
  30. Natalie Schloeder, Thomas Liu, Kurt Polzin, John Dankanich, Anne Aanesland, Mitchell Walker, “Design and Preliminary Performance Testing of Electronegative Gas Plasma Thruster,” 50th Joint Propulsion Conference and Exhibit, Cleveland, OH, July 28-30, 2014.
  31. Natalie Schloeder, Jason D. Frieman, Mitchell Walker, “Facility Effects on Helicon Plasma Source Operation,” 50th Joint Propulsion Conference and Exhibit, Cleveland, OH, July 28-30, 2014.
  32. Samuel Langendorf, Mitchell Walker, “Effects of Wall Material, Wall Temperature, and Surface Roughness on Plasma Sheath,” 50th Joint Propulsion Conference and Exhibit, Cleveland, OH, July 28-30, 2014.
  33. Jonathan Walker, Jason Frieman, Vadim Khayms, Mitchell Walker, “Hall Effect Thruster Electrical Interaction with a Conductive Vacuum Chamber,” 50th Joint Propulsion Conference and Exhibit, Cleveland, OH, July 28-30, 2014.
  34. Jason Frieman, Scott King, Vadim Khayms, Mitchell Walker, “Preliminary Assessment of the Role of a Conducting Chamber in Hall Effect Thruster Electrical Circuit,” 50th Joint Propulsion Conference and Exhibit, Cleveland, OH, July 28-30, 2014.
  35. Samuel Langendorf, Mitchell Walker, "Effects of Wall Material and Surface Roughness on the Plasma Sheath," 41st IEEE International Conference on Plasma Science, Washington DC, USA, May 25–29, 2014.
  36. Thomas Burton, Gregory Thompson, Mitchell Walker, Julian Rimoli, Aaron Schinder, German Capuano, "Microstructural Characterization of Eroded M26 HET Thruster Wall," TMS 2014 143rd Annual Meeting and Exhibition, San Diego, CA, February 16-20, 2014.
  37. John Dankanich, Mitchell Walker, Michael Swiatek, John Yim, “Recommended Practice for Pressure Measurements and Calculation of Effective Pumping Speeds during Electric Propulsion Testing,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  38. Thomas Liu, Mitchell Walker, “Integration of Electric Propulsion Systems with Spacecraft – An Overview,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  39. Lake Singh, Mitchell Walker, Graham Sanborn, Stephan Turano, Jud Ready, “Operation of Spindt-Type Carbon Nanotube Cold Cathodes in a Hall Effect Thruster Environment,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  40. Jason Frieman, Mitchell Walker, Steve Snyder, “Guide to Flow Measurement for Electric Propulsion Systems,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  41. Daniel Brown, Mitchell Walker, James Szabo, “Test Methodology and Analysis of Faraday Probes with Application to Plasma Plumes for Spacecraft Electric Propulsion,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  42. Jay Polk, Anthony Pancotti, Mitchell Walker, Thomas Haag, Joseph Blakely, John Ziemer, “Recommended Practices in Thrust Measurements,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  43. Samuel Langendorf, Mitchell Walker, Laura Rose, Lubos Brieda, Michael Keidar, “Effect of ion-neutral collisions on sheath potential profile,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  44. Jonathan Walker, Samuel Langendorf, Mitchell Walker, Kurt Polzin, Adam Kimberlin, “High-Speed Imaging of the First Kink Mode Instability in a Magnetoplasmadynamic Thruster,” 33rd International Electric Propulsion Conference, Washington, D.C., October 6-10, 2013.
  45. Aaron Schinder, Mitchell Walker, Julian Rimoli, “3D Model for Atomic Sputtering of Heterogeneous Ceramic Compounds,” 49th Joint Propulsion Conference and Exhibit, San Jose, CA, July 15-17, 2013.
  46. Samuel Langendorf, Mitchell Walker, Laura Rose, Michael Keidar, Lubos Brieda, “Wall Material Effects on Sheath Potential Profile,” 49th Joint Propulsion Conference and Exhibit, San Jose, CA, July 15-17, 2013.
  47. Kunning Xu, Mitchell Walker, "Potential Contours in Ion Focusing Thruster,” 48th Joint Propulsion Conference & Exhibit, Atlanta, GA, July 2012.
  48. Lake Singh, Mitchell Walker, “Orbit Perturbation of High Area-to-Mass Objects with High-Energy Neutrals from Charge Exchange Collisions with Near-Earth Protons,” 39th COSPAR Scientific Assembly, Mysore, India, July 2012.
  49. Robert Hoyt, Jonathan Wrobel, Jonathan Walker, Samuel Langendorf, Mitchell Walker, “Thrust Performance of an MPD Thruster with a Ring-Cusp Magnetic Nozzle,” JANNAF Propulsion Meeting, Huntsville, AL, December 5-8, 2011.
  50. Alexander Kieckhafer, Mitchell Walker, “Recirculating Liquid Nitrogen System for Operation of Cryogenic Pumps,” 32nd International Electric Propulsion Conference, Hamburg, Germany, September 2011.
  51. Kunning Xu, Mitchell Walker, “Plume Characterization of an Ion Focusing Hall Thruster,” 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 31 July - 03 August 2011, San Diego, California.
  52. Logan Williams, Mitchell Walker, “Thrust Measurements of a Helicon Plasma Source” 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 31 July - 03 August 2011, San Diego, California.
  53. Scott King, Mitchell Walker, “Ambient Atmosphere Ion Thruster Proof-of-concept Modeling,” 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 31 July - 03 August 2011, San Diego, California.
  54. Kybeom Kwon, Dmitri Mavris, Mitchell Walker, "A New Approach for Numerical Analysis of Hall Thrusters," AIAA-2010-6523, 46th Joint Propulsion Conference, Nashville, TN, July 25-28, 2010.
  55. Kunning Xu, Mitchell Walker, "Evaluation of Technique to Focus Ions in Hall Effect Thruster Discharge Chamber," JANNAF Propulsion Meeting, Colorado Springs, CO, May 3-7, 2010.
  56. Logan Williams, Mitchell Walker, Victor Kumsomboone, Jud Ready, “Experimental Characterization of Carbon Nanotube Cold Cathode Lifetime Operation”, 45th Joint Propulsion Conference, Denver, CO, August 2-5, 2009.
  57. John Carlsson, Danielle Pavarin, Mitchell Walker, "Analytic Wave Solution with Helicon and Trivelpiece-Gould Modes in an Annular Plasma," B61, 18th Topical Conference on Radio Frequency Power in Plasmas, Gent, Belgium, June 24-26, 2009.
  58. Logan Williams, Mitchell Walker, “Experimental Characterization of a Carbon Nanotube Field Emission Cathode”, AIAA-2008-5015, 44th Joint Propulsion Conference, Hartford, CT, July 20-23, 2008.
  59. Doug Palmer, Mitchell Walker, “Performance of an Annular Helicon Plasma Source”, AIAA-2008-4926, 44th Joint Propulsion Conference, Hartford, CT, July 20-23, 2008.
  60. Doug Palmer, Mitchell Walker, Marco Manente, John Carlsson, Christina Bramanti, Danielle Pavarin, “Performance Analysis of a Medium-Power Helicon Thruster”, AIAA-2008-4925, 44th Joint Propulsion Conference, Hartford, CT, July 20-23, 2008.
  61. Danielle Pavarin, Marco Manente, Mitchell Walker, Doug Palmer, John Carlsson, Christina Bramanti, Enrico Lorenzini, “Feasibility Study of a Medium-Power Helicon Thruster”, AIAA-2008-4927, 44th Joint Propulsion Conference, Hartford, CT, July 20-23, 2008.
  62. Scott King, Mitchell Walker, Craig Kluever, “Small Satellite LEO Maneuvers with Low-Power Electric Propulsion ”, AIAA-2008-4516, 44th Joint Propulsion Conference, Hartford, CT, July 20-23, 2008.
  63. Doug Palmer, Mitchell Walker, Marco Manente, John Carlsson, Christina Bramanti, Danielle Pavarin, “Experimental Analysis of Low-Power Helicon Thruster”, 5th International Spacecraft Propulsion Conference, Crete, Greece, May 5-9, 2008.
  64. Marco Manente, Mitchell Walker, John Carlsson, Christina Bramanti, Danielle Pavarin, “Feasibility Study of Low-Power Helicon Thruster”, 5th International Spacecraft Propulsion Conference, Crete, Greece, May 5-9, 2008.
  65. Doug Palmer, Cengiz Akinli, Mitchell Walker, “Characterization of an Annular Helicon Plasma Source”, IEPC-2007-202, International Electric Propulsion Conference, Florence, Italy, September 17-20, 2007.
  66. Cengiz Akinli, Doug Palmer, Mitchell Walker, “Comparison of the Theoretical and Experimental Performance of an Annular Helicon Plasma Source”, IEPC-2007-236, International Electric Propulsion Conference, Florence, Italy, September 17-20, 2007.
  67. Robert Stubbers, Brian Jurczyk, Joshua Rovey, Mitchell Walker, Darren Alman, Matthew Coventry, “Compact Toroid Formation Using an Annular Helicon Preionization Source”, AIAA-2007-5307, 43rd Joint Propulsion Conference, Cincinnati, OH, July 8-11, 2007.
  68. Masayuki Yano, Logan Williams, Mitchell Walker “Design and Operation of an Annular Helicon Plasma Source”, AIAA-2007-5309, 43rd Joint Propulsion Conference, Cincinnati, OH, July 8-11, 2007.
  69. James Gilland, Mitchell Walker, Eric Pencil, "Thrust Stand for Applied Field MPD Thrusters", IEPC-2005-215, 29th International Electric Propulsion Conference, Princeton, NJ, Oct. 31-Nov. 4, 2005.
  70. Mitchell Walker, Alec Gallimore, "Performance Characteristics of a Cluster of 5 kW Laboratory Hall Thrusters," AIAA-2004-3767, 40th Joint Propulsion Conference, Fort Lauderdale, FL, July 11-14, 2004.
  71. Joshua Rovey, Mitchell Walker, Alec Gallimore, Peter Peterson, "Evaluation of a Magnetically-Filtered Faraday Probe for measuring the ion current density profile of a Hall thruster," AIAA-2004-3948, 40th Joint Propulsion Conference, Fort Lauderdale, FL, July 11-14, 2004.
  72. Mitchell Walker, Alec Gallimore, "Hot Flow Pressure Map of a Vacuum Facility as a Function of Flow Rate to Study Facility Effects," IEPC-0077-03, 28th International Electric Propulsion Conference, Toulouse, France, March 17-21, 2003.
  73. Mitchell Walker, Alec Gallimore, Chunpei Cai, Ian Boyd, "Pressure Map of a Facility as a Function of Flow Rate to Study Facility Effects," AIAA-2002-3815, 38th Joint Propulsion Conference, Indianapolis, IN, July 7-10, 2002.
  74. Mitchell Walker, Richard Hofer, Alec Gallimore, "The Effects of Nude Faraday Probe Design and Vacuum Facility Backpressure on the Measured Ion Current Density Profile of Hall Thruster Plumes," AIAA-2002-4253, 38th Joint Propulsion Conference, Indianapolis, IN, July 7-10, 2002.
  75. Richard Hofer, Mitchell Walker, Alec Gallimore, "A Comparison of Nude and Collimated Faraday Probes for Use with Hall Thrusters," IEPC-01-020, 27th International Electric Propulsion Conference, Pasadena, CA, October 15-19, 2001.

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Doctoral Dissertations

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  1. Chhavi, "Investigation of the Impact of Azimuthal Magnetic Field Gradient on Performance Characteristics and Stability of Hall Effect Thrusters," July 2024
  2. Jean Luis Suazo Betancourt, "Laser Thomson Scattering Measurements of the Plasma Structure in the Front Pole Region of a Magnetically-shielded Hall Effect Thruster," April 2024
  3. David R. Jovel, "Impedance Characterization of a Hall Effect Thruster Discharge in a Ground-based Vacuum Test Facility," December 2023.
  4. Nathan P. Brown, "Development and Evaluation of Terahertz Time-Domain Spectroscopy for Electric Propulsion Plasma Diagnostics," November 2020.
  5. Connie Y. Liu, "Investigating Physics of Nanosecond- Pulsed Argon Plasma Discharges for a VLF Plasma Antenna," May 2019.
  6. Hisham Ali, "Magnetohydrodynamic Energy Generation and Flow Control for Planetary Entry Vehicles," May 2019.
  7. Jason Frieman, "Characterization of Background Neutral Flows in Vacuum Test Facilities and Impacts on Hall Effect Thruster Operation," April 2017.
  8. Jonathan Walker, "Electrical Facility Effects on Hall Effect Thruster Operation," November 2016.
  9. Aaron Schinder, "Investigation of Hall Effect Thruster Channel Wall Erosion Mechanisms," August 2016.
  10. Natalie (Schloeder) Caruso, "Facility Effects On Helicon Thruster Operation," March 2016.
  11. Samuel Langendorf, "Effects of Electron Emission on Plasma Sheaths," October 2015.
  12. Lake Singh, "Very Low Earth Orbit Propellant Collection Feasibility Assessment," September 2014.
  13. Logan Williams, "Ion Acceleration Mechanisms of Helicon Thrusters," May 2013.
  14. Kunning Xu, "Ion Collimation and In-Channel Potential Shaping Using In-Channel Electrodes For Hall Effect Thrusters," June 2012.
  15. Kybeom Kwon, "A Novel Numerical Analysis of Hall Effect Thruster and its Application in Simultaneous Design of Thruster and Optimal Low-Thrust Trajectory," August 2010.

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Other Publications

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  1. Humphreys, D., Bonoli, P., Casali, L., Ferraro, N., Field, K., Gleason, A., Holcomb, C., Humrickhouse, P., Ma, T., Magee, R., Marian, J., Murph, S., Paz-Soldan, C., Walker, M. L. R., White, A., "FESAC International  Benchmarking Report on International Collaboration Opportunities, Modes, and Workforce Impacts for Advancement of US Fusion Energy," November 2023.
  2. B. Jorns, A. Yalin, M. L. R. Walker, J. Little, K. Hara, Y. Raitses, A. Smolyakov, I. Kaganovich, and M. Cappelli, "Plasma Propulsion Research in Academia," National Academy of Sciences, 2020 Decadal Assessment of Plasma Science, 2019.
  3. Vigor Yang, David D. Ku, Mitchell Walker, Logan T. Williams, Joe C. Leahy, "Liquid Oxygen/Kerosene Staged Combustion Rocket Engines with Oxidizer-Rich Preburners," NASA/TP 2015-218203, 2015, 258 pages.
  4. Mitchell Walker, "Electric Propulsion," Aerospace America, No. 12, December 15, 2005, pp. 54-55.
  5. Doug Palmer, Masayuki Yano, Mitchell Walker, “Characterization of Cylindrical and Annular Helicon Plasma Sources”, 9th International Workshop on the Interrelationship between Plasma Experiments in Laboratory and Space, Cairns, Australia, August 5-10, 2007.
  6. National Research Council. Reusable Booster System:  Review and Assessment. Washington, DC:  The National Academies Press, 2012.
    Authors:  D. M. Van Wie, E. H. Bock, Y. C. Brill, A. V. Burman, D. C. Byers, L. H. Caveny, R. S. Dickman, M. K. Jacobs, T. J. Lee, C. K. N. Patel, D. Roussel-Dupre, R. L. Sackheim, P. D. Spanos, M. L. R. Walker, B. T. Zinn
  7. “In-Space Propulsion:  Strategic Choices and Options,” Space Subcommittee Hearing, House of Representatives, Washington, D.C., June 29, 2017. – Invited.