Electron transport across magnetic field in low-temperature plasmas : an alternative approach for obtaining evidence of Bohm mechanism

A comparative study involving both experimental and numerical investigations was made to resolve a long-standing problem of understanding electron conductivity mechanism across magnetic field in low-temperature plasmas. We have calculated the plasma parameters from experimentally obtained electric field distribution, and then made a 'back' comparison with the distributions of electron energy and plasma density obtained in the experiment. This approach significantly reduces an influence of the assumption about particular phenomenology of the electron conductivity in plasma. The results of the experiment and calculations made by this technique have showed that the classical conductivity is not capable of providing realistic total current and electron energy, whereas the phenomenological anomalous Bohm mobility has demonstrated a very good agreement with the experiment. These results provide an evidence in favor of the Bohm conductivity, thus making it possible to clarify this pressing long-living question about the main driving mechanism responsible for the electron transport in low-temperature plasmas.

[1]  I. Jones,et al.  An experimental investigation of the toroidal magnetic field structure of a rotamak discharge , 1993 .

[2]  N. Fisch,et al.  Plasma measurements in a 100 W cylindrical Hall thruster , 2004 .

[3]  M. Keidar,et al.  Magnetic field effect on the sheath thickness in plasma immersion ion implantation , 2002 .

[4]  K. Ostrikov,et al.  Carbon saturation of arrays of Ni catalyst nanoparticles of different size and pattern uniformity on a silicon substrate , 2008, Nanotechnology.

[5]  M. Keidar,et al.  Electron transport phenomena in plasma devices with E/spl times/B drift , 2006, IEEE Transactions on Plasma Science.

[6]  A. Simon.  Comment on ‘Two-dimensional equilibrium of a low temperature magnetized plasma’ , 2008 .

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

[8]  M. Ranjan,et al.  Effect of electron emission and potential perturbations of a hot filament in high voltage pulsed glow discharge , 2008 .

[9]  M. Keidar,et al.  Modeling of a high-power thruster with anode layer , 2004 .

[10]  A. Morozov,et al.  Theory of the near-wall conductivity , 2001 .

[11]  P. Shukla,et al.  Bohm criterion for a plasma composed of electrons and positive dust grains. , 2000, Physical review. E, Statistical, nonlinear, and soft matter physics.

[12]  L. Garrigues,et al.  Two-dimensional model of a stationary plasma thruster , 2002 .

[13]  Brussaard,et al.  Langmuir probe measurements in an expanding magnetized plasma. , 1996, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

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

[15]  A. Anders.  Width, structure and stability of sheaths in metal plasma immersion ion implantation and deposition: measurements and analytical considerations , 2001 .

[16]  R. K. Wakerling,et al.  The characteristics of electrical discharges in magnetic fields , 1949 .

[17]  C. Bourdelle,et al.  Turbulent particle transport in magnetized fusion plasma , 2004, physics/0410216.

[18]  Yevgeny Raitses,et al.  Electron Cross-field Transport in a Low Power Cylindrical Hall Thruster , 2004 .

[19]  S. Xu,et al.  Power transfer and mode transitions in low-frequency inductively coupled plasmas , 2000 .

[20]  O. Tarvainen,et al.  Electron–cyclotron–resonance plasma heating with broadband microwave radiation: Anomalous effects , 2007 .

[21]  Michael Keidar,et al.  Investigation of a steady-state cylindrical magnetron discharge for plasma immersion treatment , 2003 .

[22]  A. Ricard,et al.  Characterization of oxygen plasma with a fiber optic catalytic probe and determination of recombination coefficients , 2004, IEEE Transactions on Plasma Science.

[23]  Michael Keidar,et al.  Stable plasma configurations in a cylindrical magnetron discharge , 2004 .

[24]  L. Page,et al.  Space Charge in Cylindrical Magnetron , 1946 .

[25]  Davide Mariotti,et al.  Self-organized nanostructures on atmospheric microplasma exposed surfaces , 2007 .

[26]  N. Fisch,et al.  Effects of segmented electrode in Hall current plasma thrusters , 2001 .

[27]  Kostya Ostrikov,et al.  Colloquium: Reactive plasmas as a versatile nanofabrication tool , 2005 .

[28]  Michael Keidar,et al.  Increasing the length of single-wall carbon nanotubes in a magnetically enhanced arc discharge , 2008 .

[29]  Anthony B. Murphy,et al.  Plasma-deposited Ge nanoisland films on Si: is Stranski–Krastanow fragmentation unavoidable? , 2008 .