Test charge response for a dusty plasma with both grain size distribution and dynamical charging

• The form of the grain size distribution strongly influences the linear dielectric response of a dusty plasma. For a class of size distributions and a thermal velocity distribution, there is an equivalence to a Lorentzian distribution of monosized particles. The electrostatic response to a slowly moving test charge can then be found. Dynamical charging of grains in a dusty plasma leads to an enhanced time-dependent shielding of a test charge. Here the combined effect of both grain size distribution and dynamical grain charging on the response to a slowly moving test charge is analyzed. The dynamical charging contribution to the plasma dielectric has a complicated dependence on the parameters for the size distribution and on the charging rate. However, this dependence can be expressed in terms of known functions. Series expansions are used to derive the potential response to a slowly moving test charge. Previously known results may be recovered as special limiting cases of this investigation. The analytical expression for the plasma dielectric may be used for more general cases and is applicable to the study of electrostatic waves.

Ämnesord

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

Nyckelord

moving test charge

energy-loss

dispersion function

projectiles

particles

Plasma physics

Plasmafysik

Publikations- och innehållstyp

ref (ämneskategori)

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