An Electron Trap for Studying Cross-Field Mobility in Hall Thrusters

An electron-trapping apparatus was constructed to study electron dynamics in the defining fields of a Hall-effect thruster. An electron plasma is confined using vacuum electric and magnetic fields in the absence of neutral-plasma effects and dielectric walls, which are present in a typical Hall thruster. Crossfield electron mobility was investigated in response to changes in magnetic and electric field strengths and background neutral density, and has been found to be much larger than what classical theory predicts. Experimental mobility is on the same order as Bohm mobility; however, the agreement with Bohm mobility is suspected to be coincidental, and the elevated mobility observed is thought to be due to static electric field asymmetries or external electrostatic perturbations, which can be correlated with electrostatic disturbances found in a Hall thruster.

[1]  L. Garrigues,et al.  Low frequency oscillations in a stationary plasma thruster , 1998 .

[2]  Ioannis G. Mikellides,et al.  Wall Sheath and Electron Mobility Modeling in Hybrid-PIC Hall Thruster Simulations , 2007 .

[3]  R. Davidson,et al.  Physics of Nonneutral Plasmas , 1991 .

[4]  J. P. Kremer,et al.  Confinement of plasmas of arbitrary neutrality in a stellarator , 2004 .

[5]  N. Meezan,et al.  Anomalous electron mobility in a coaxial Hall discharge plasma. , 2000, Physical review. E, Statistical, nonlinear, and soft matter physics.

[6]  Ronald A. Spores,et al.  Analysis of Hall-effect thrusters and ion engines for orbit transfer missions , 1996 .

[7]  J. P. Kremer,et al.  Diagnosing pure-electron plasmas with internal particle flux probes. , 2007, The Review of scientific instruments.

[8]  G. Janes,et al.  Anomalous Electron Diffusion and Ion Acceleration in a Low‐Density Plasma , 1966 .

[9]  Electron confinement in an annular Penning trap , 2000 .

[10]  L. B. King.  A (Re-) examination of electron motion in Hall thruster fields , 2005 .

[11]  M. Keidar,et al.  Plasma flow and plasma–wall transition in Hall thruster channel , 2001 .

[12]  R. Schneider,et al.  Fully kinetic 2D{r,theta} model of a Hall discharge , 2007 .

[13]  M. Cappelli,et al.  Plasma instabilities in the ionization regime of a Hall thruster , 2003 .

[14]  R. Spektor.  Quasi-Linear Analysis Of Anomalous Electron Mobility Inside A Hall Thruster , 2007 .

[15]  Z. Yoshida,et al.  Probing of flowing electron plasmas , 2001 .

[16]  A. Smolyakov,et al.  Kinetic effects in a Hall thruster discharge , 2006 .

[17]  C. Michaut,et al.  Characterization of high frequency oscillations in a small Hall-type thruster , 1999 .

[18]  Jason M. Makela,et al.  Mobility Studies of a Pure Electron Plasma in Hall Thruster Fields , 2006 .

[19]  E. Choueiri.  Plasma oscillations in Hall thrusters , 2001 .

[20]  J. Degrassie.  Equilibrium, waves and transport in the pure electron plasma , 1977 .

[21]  D. Pines.  A Collective Description of Electron Interactions: II. Collective vs Individual Particle Aspects of the Interactions , 1952 .

[22]  Yoon Ho Choi,et al.  Internal plasma potential measurements of a Hall thruster using xenon and krypton propellant (10 pages) , 2006 .

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

[24]  J. Degrassie,et al.  Properties of nonneutral plasma , 1975 .

[25]  N. Fisch,et al.  Electron-wall Interaction in Hall Thrusters , 2005 .

[26]  N. Meezan,et al.  Kinetic study of wall collisions in a coaxial Hall discharge. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[27]  A. R. Hutson.  Velocity Analysis of Thermionic Emission from Single-Crystal Tungsten , 1955 .

[28]  Shear-Based Model for Electron Transport in 2D Hybrid Hall Thruster Simulations , 2007 .

[29]  I. Hutchinson.  Principles of Plasma Diagnostics , 1987 .

[30]  S. Paul,et al.  Effects of background gas pressure on the dynamics of a nonneutral electron plasma confined in a Malmberg–Penning trap , 2000 .

[31]  Neoclassical effects in the annular Penning trap , 2001 .

[32]  R. S. Robinson,et al.  Physics of closed drift thrusters , 1999 .

[33]  M. Cappelli,et al.  Laser-induced fluorescence measurements of velocity within a Hall discharge , 2001 .

[34]  J. Adam,et al.  High-frequency electron drift instability in the cross-field configuration of Hall thrusters , 2006 .

[35]  Joshua L. Rovey,et al.  A Planar Hall Thruster for Investigating Electron Mobility in ExB Devices (Preprint) , 2007 .