  The maximum magnetic field strength generated by Weibel-type plasma
instabilities is estimated for typical conditions in the interstellar medium.
The relevant kinetic dispersion relations are evaluated by conducting a
parameter study both for Maxwellian and for suprathermal particle distributions
showing that micro Gauss magnetic fields can be generated. It is shown that,
depending on the streaming velocity and the plasma temperatures, either the
longitudinal or a transverse instability will be dominant. In the presence of
an ambient magnetic field, the filamentation instability is typically
suppressed while the two-stream and the classic Weibel instability are
retained.
