  Neutron capture cross sections are one of the most important nuclear inputs
to models of stellar nucleosynthesis of the elements heavier than iron. The
activation technique and the time-of-flight method are mostly used to determine
the required data experimentally. Recent developments of experimental
techniques allow for new experiments on radioactive isotopes. Monte-Carlo based
analysis methods give new insights into the systematic uncertainties of
previous measurements. We present an overview over the state-of-the-art
experimental techniques, a detailed new evaluation of the
$^{197}$Au(n,$\gamma$) cross section in the keV-regime and the corresponding
re-evaluation of 63 more isotopes, which have been measured in the past
relative to the gold cross section.
