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

TL;DR

This paper characterizes germanium detectors used at J-PARC's ANNRI for measuring gamma-ray angular distributions, developing a GEANT4-based simulation to accurately reproduce gamma-ray spectra from various sources.

Contribution

It introduces a detailed Monte Carlo simulation for germanium detector response, enabling precise gamma-ray measurements in neutron-induced reactions.

Findings

Simulation accurately reproduces pulse-height spectra

Applicable to gamma-ray energies 0.5-11.0 MeV

Enhances measurement of gamma-ray angular distributions

Abstract

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-ray transitions 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-rays from radioactive sources and (n,gamma) reactions. The simulation is applicable to the measurement of gamma-rays in the energy region of 0.5-11.0 MeV.