Development of a 4π germanium spectrometer for nuclear data measurements at J-PARC

A 4π germanium spectrometer was developed for measurements of neutron capture cross sections of minor actinides and long-lived-fission products. It was installed on the Beam Line No. 04 of the MLF in the J-PARC. We measured its full-energy peak efficiency and gamma-energy resolution at 1.3-MeV with a
⁶⁰
Co standard source (10kBq). As an example of a result of TOF measurements with the spectrometer, preliminary TOF and energy spectra of
¹⁰⁸
Pd are shown in this paper.