There is broad consensus in the worldwide physics community as to the need for a new reactor-neutrino experiment to measure or limit the neutrino mixing angle θ13. The Double Chooz Experiment, planned for operation in the years 2008−2011, will search for values of sin2 2θ13 down to ≈0.03. This will be the first new information on θ13 in over a decade and will cover most of the remaining paramet...