  The field of nuclear astrophysics is devoted to the study of the creation of
the chemical elements. By nature, it is deeply intertwined with the physics of
the Sun. The nuclear reactions of the proton-proton cycle of hydrogen burning,
including the 3He({\alpha},{\gamma})7Be reaction, provide the necessary nuclear
energy to prevent the gravitational collapse of the Sun and give rise to the by
now well-studied pp, 7Be, and 8B solar neutrinos. The not yet measured flux of
13N, 15O, and 17F neutrinos from the carbon-nitrogen-oxygen cycle is affected
in rate by the 14N(p,{\gamma})15O reaction and in emission profile by the
12C(p,{\gamma})13N reaction. The nucleosynthetic output of the subsequent phase
in stellar evolution, helium burning, is controlled by the
12C({\alpha},{\gamma})16O reaction.
  In order to properly interpret the existing and upcoming solar neutrino data,
precise nuclear physics information is needed. For nuclear reactions between
light, stable nuclei, the best available technique are experiments with small
ion accelerators in underground, low-background settings. The pioneering work
in this regard has been done by the LUNA collaboration at Gran Sasso/Italy,
using a 0.4 MV accelerator.
  The present contribution reports on a higher-energy, 5.0 MV, underground
accelerator in the Felsenkeller underground site in Dresden/Germany. Results
from {\gamma}-ray, neutron, and muon background measurements in the
Felsenkeller underground site in Dresden, Germany, show that the background
conditions are satisfactory for nuclear astrophysics purposes. The accelerator
is in the commissioning phase and will provide intense, up to 50{\mu}A, beams
of 1H+, 4He+ , and 12C+ ions, enabling research on astrophysically relevant
nuclear reactions with unprecedented sensitivity.
