  Long-lived radioactive nuclei play an important role as
nucleo-cosmochronometers and as cosmic tracers of nucleosynthetic source
activity. In particular nuclei in the actinide region like thorium, uranium,
and plutonium can testify to the enrichment of an environment by the still
enigmatic astrophysical sources that are responsible for the production of
neutron-rich nuclei by the rapid neutron-capture process (r-process).
Supernovae and merging neutron-star (NS) or NS-black hole binaries are
considered as most likely sources of the r-nuclei. But arguments in favour of
one or the other or both are indirect and make use of assumptions; they are
based on theoretical models with remaining simplifications and shortcomings. An
unambiguous observational determination of a production event is still missing.
In order to facilitate searches in this direction, e.g.\ by looking for
radioactive tracers in stellar envelopes, the interstellar medium or
terrestrial reservoirs, we provide improved theoretical estimates and
corresponding uncertainty ranges for the actinide production ($^{232}$Th,
$^{235,236,238}$U, $^{237}$Np, $^{244}$Pu, and $^{247}$Cm) in neutrino-driven
winds of core-collapse supernovae. Since state-of-the-art supernova models do
not yield r-process viable conditions ---but still lack, for example, the
effects of strong magnetic fields--- we base our investigation on a simple
analytical, Newtonian, adiabatic and steady-state wind model and consider the
superposition of a large number of contributing components, whose
nucleosynthesis-relevant parameters (mass weight, entropy, expansion time
scale, and neutron excess) are constrained by the assumption that the
integrated wind nucleosynthesis closely reproduces the solar system
distribution of r-process elements. We also test the influence of uncertain
nuclear physics.
