Optimierung der Fluoreszenzcharakteristik von Flüssigszintillatoren des Double Chooz Reaktorneutrinoexperiments

The goal of the reactor neutrino experiment Double Chooz is to search for the last remaining unknown neutrino mixing angle 13 of the PMNS matrix. This disappearence experiment aims at detecting possible oscillations of electron antineutrinos at a distance of one kilometer. A relative measurement will be done between a far and a near detector, each of them containing several cubic meters of Gadoliniumloaded organic liquid scintillator as a neutrino target. A second unloaded scintillator surrounds the neutrino target and acts as a Gamma Catcher. Different compositions of scintillators have been studied to optimize their properties. Light yields and time probability density functions of the scintillator emission have been measured. A model has been developed describing the energy transfer to predict the light yield of different scintillator compositions. The predictions have been checked with a Compton backscatter peak method. The result of the optimization process is a light yield and density matching of the two chemically different scintillators with per cent accuracy. Different time PDFs could be used for a pulse shape discrimination in Double Chooz. The results of this work determine the mixing ratios and the concentrations for the target and the gamma catcher scintillator of Double Chooz