  In the forthcoming months, the KamLAND experiment will probe the parameter
space of the solar large mixing angle (LMA) MSW solution as the origin of the
solar neutrino deficit with $\nuebar$'s from distant nuclear reactors. If
however the solution realized in nature is such that $\Dm2_{sol} \gsim 2 \cdot
10^{-4}$ eV$^2$ (thereafter named the HLMA region), KamLAND will only observe a
rate suppression but no spectral distortion and hence it will not have the
optimal sensitivity to measure the mixing parameters. In this case, we propose
a new medium baseline reactor experiment located at Heilbronn (Germany) to pin
down the precise value of the solar mixing parameters. In this paper, we
present the Heilbronn detector site, we calculate the $\nuebar$ interaction
rate and the positron spectrum expected from the surrounding nuclear power
plants. We also discuss the sensitivity of such an experiment to |U_e3| in both
normal and inverted neutrino mass hierarchy scenarios. We then outline the
detector design, estimate background signals induced by natural radioactivity
as well as by in-situ cosmic ray muon interaction, and discuss a strategy to
detect the anti-neutrino signal 'free of background'.
