The spectral density of electrostatic fluctuations is investigated
in a plasma
containing an excess of suprathermal particles. As a model for the statistical
distribution
of the suprathermal particles, the kappa velocity distribution is used.
It is found
that the Debye length λD for
such a plasma depends strongly on the spectral index
κ of the velocity distribution, and can be much smaller than is commonly
found for
Maxwellian plasmas. Consequently the plasma parameter
g=1/nλ3D can
be larger,
and plasma effects that depend on particle discreteness more important,
than for
a Maxwellian plasma. Consequently, levels of fluctuation are higher, and
their
extent in wavenumber and frequency greater, in plasmas containing suprathermals.
Results for a number of different ‘concentrations’ of suprathermal
particles are
discussed and interpreted in terms of the normal- as well as transient-mode
behaviour
of the plasma. Both the cases
Te[Gt ]Ti and
Te=Ti, as well
as
κe[Lt ]κi and
κe[Gt ]κi, are investigated.