Characterization of Germanium Detectors for the Measurement of the Angular Distribution of Prompt gamma-rays at the ANNRI in the MLF of the J-PARC

In this study, the germanium detector assembly, installed at the Accurate Neutron- Nuclear Reaction measurement Instruments(ANNRI) in the Material and Life Science Facility (MLF) operated by the Japan Proton Accelerator Research Complex ( J-PARC), has been characterized for extension to the measurement of the angular distribution of individual gamma-raytransitions from neutron-induced compound states. We have developed a Monte Carlo simulation code using the GEANT4 toolkit, which can reproduce the pulse-height spectra of gamma-raysfrom radioactive sourcesand (n,gamma) reactions. The simulation is applicable to the measurement of gamma-raysin the energy region of 0.5-11.0 MeV.