The Double Chooz experiment aims for the measurement of neutrino oscillations. Of special interest in this experiment is the yet still unknown mixing angle θ₁₃. This parameter is a crucial part in the description of the transformation of electron antineutrinos in neutrinos of different flavours. For this purpose the reactor cores of the nuclear power plant Chooz are used as sources of electron antineutrinos. These particles are produced in the reactor cores during the nuclear reactions and can easily leave the reactor building due to their small cross section. Since the production rate of the antineutrinos is proportional to the well known electrical energy output, a measurement of the antineutrino flux in different distances from the reactor cores yields the number of electron antineutrinos which have converted into neutrinos of other flavours during their travel to the detectors.