A New Method for Analyzing Near-Field Faraday Probe Data in Hall Thrusters

Abstract This paper presents a new method for analyzing near-field Faraday probe data obtained from Hall thrusters. Traditional methods spawned from far-field Faraday probe analysis rely on assumptions that are not applicable to near-field Faraday probe data. In particular, arbitrary choices for the point of origin and limits of integration have made interpretation of the results difficult. The new method, called iterative pathfinding, uses the evolution of the near-field plume with distance to provide feedback for determining the location of the point of origin. Although still susceptible to the choice of integration limits, this method presents a systematic approach to determining the origin point for calculating the divergence angle. The iterative pathfinding method is applied to near-field Faraday probe data taken in a previous study from the NASA-300M and NASA-457Mv2 Hall thrusters. Since these two thrusters use centrally mounted cathodes, the current density associated with the cathode plume is removed before applying iterative pathfinding. A procedure is presented for removing the cathode plume. The results of the analysis are compared to far-field probe analysis results. This paper ends with checks on the validity of the new method and discussions on the implications of the results.

[1]  A. Mathers,et al.  Demonstration of 10,400 Hours of Operation on a 4.5 kW Qualification Model Hall Thruster , 2010 .

[2]  I. Mikellides,et al.  Design of a Laboratory Hall Thruster with Magnetically Shielded Channel Walls, Phase II: Experiments , 2012 .

[3]  V. Altuzar,et al.  Atmospheric pollution profiles in Mexico City in two different seasons , 2003 .

[4]  李幼升,et al.  Ph , 1989 .

[5]  I. Mikellides,et al.  Design of a Laboratory Hall Thruster with Magnetically Shielded Channel Walls, Phase III: Comparison of Theory with Experiment , 2012 .

[6]  Hani Kamhawi,et al.  Ion Current Density Study of the NASA-300m and NASA-457mv2 Hall Thrusters , 2013 .

[7]  P. Peterson,et al.  A High Specific Impulse Two-Stage Hall Thruster with Plasma Lens Focusing , 2001 .

[8]  A. Gallimore,et al.  Plasma Potential Measurements in the Discharge Channel of a 6-kW Hall Thruster , 2008 .

[9]  Hani Kamhawi,et al.  Farfield Plume Measurement and Analysis on the NASA-300M , 2013 .

[10]  Hani Kamhawi,et al.  Farfield Ion Current Density Measurements before and after the NASA HiVHAc EDU2 Vibration Test , 2012 .

[11]  Homer D. Hagstrum,et al.  Auger Ejection of Electrons from Molybdenum by Noble Gas Ions , 1956 .

[12]  Alec D. Gallimore,et al.  Evaluation of Facility Effects on Ion Migration in a Hall Thruster Plume , 2011 .

[13]  Homer D. Hagstrum,et al.  AUGER EJECTION OF ELECTRONS FROM TUNGSTEN BY NOBLE GAS IONS , 1954 .

[14]  A. Gallimore,et al.  Recent Results From Internal and Very-Near-Field Plasma Diagnostics of a High Specific Impulse Hall Thruster , 2003 .

[15]  Alec D Gallimore,et al.  Evaluation of ion collection area in Faraday probes. , 2010, The Review of scientific instruments.

[16]  Lee S. Mason,et al.  Benefits of Power and Propulsion Technology for a Piloted Electric Vehicle to an Asteroid , 2011 .

[17]  A. Gallimore,et al.  Development of a high-speed, reciprocating electrostatic probe system for Hall thruster interrogation , 2000 .

[18]  Daniel L. Brown,et al.  Investigation of low discharge voltage Hall thruster characteristics and evaluation of loss mechanisms , 2009 .

[19]  A. Gallimore,et al.  The Role of Magnetic Field Topography in Improving the Performance of High-Voltage Hall Thrusters , 2002 .

[20]  Hani Kamhawi,et al.  Performance Evaluation of the NASA-300M 20 kW Hall Thruster , 2011 .

[21]  Kristina Kathleen Jameson,et al.  Investigation of hollow cathode effects on total thruster efficiency in a 6 kW Hall thruster , 2008 .

[22]  B. M. Reid,et al.  The Influence of Neutral Flow Rate in the Operation of Hall Thrusters. , 2009 .

[23]  Rohit Shastry,et al.  Experimental Characterization of the Near-Wall Region in Hall Thrusters and its Implications on Performance and Lifetime. , 2011 .

[24]  R. Hofer,et al.  Development and characterization of high -efficiency, high -specific impulse xenon Hall thrusters. , 2004 .

[25]  V. Kim.  Main Physical Features and Processes Determining the Performance of Stationary Plasma Thrusters , 1998 .

[26]  H. Kamhawi,et al.  Plasma Potential and Langmuir Probe Measurements in the Near-Field Plume of the NASA-457mv2 Hall Thruster , 2013 .

[27]  Alec D. Gallimore,et al.  Near-field Ion Current Density Measurements of a 6-kW Hall Thruster , 2009 .

[28]  A. Gallimore,et al.  Internal plasma potential profiles in a laboratory-model Hall thruster , 2001 .

[29]  Charles Finley,et al.  TacSat-2: A Story of Survival , 2007 .