  The relevant interaction energies for astrophysical radiative capture
reactions are very low, much below the repulsive Coulomb barrier. This leads to
low cross sections, low counting rates in $\gamma$-ray detectors, and therefore
the need to perform such experiments at ion accelerators placed in underground
settings, shielded from cosmic rays. Here, the feasibility of such experiments
in the new shallow-underground accelerator laboratory in tunnels VIII and IX of
the Felsenkeller site in Dresden, Germany, is evaluated. To this end, the
no-beam background in three different types of germanium detectors, i.e. a
Euroball/Miniball triple cluster and two large monolithic detectors, is
measured over periods of 26-66 days. The cosmic-ray induced background is found
to be reduced by a factor of 500-2400, by the combined effects of, first, the
140 meters water equivalent overburden attenuating the cosmic muon flux by a
factor of 40, and second, scintillation veto detectors gating out most of the
remaining muon-induced effects. The new background data are compared to spectra
taken with the same detectors at the Earth's surface and at other underground
sites. Subsequently, the beam intensity from the cesium sputter ion source
installed in Felsenkeller has been studied over periods of several hours. Based
on the background and beam intensity data reported here, for the example of the
$^{12}$C($\alpha$,$\gamma$)$^{16}$O reaction it is shown that highly sensitive
experiments will be possible.
