Measurement of neutron capture rays from the resonances of Zr and Zr at the J-PARC/MLF/ANNRI

Hori, Junichi*; Furutaka, Kazuyoshi  ; Goko, Shinji*; Harada, Hideo   ; Kimura, Atsushi   ; Kin, Tadahiro; Kitatani, Fumito  ; Koizumi, Mitsuo ; Nakamura, Shoji  ; Ota, Masayuki*; Oshima, Masumi; Toh, Yosuke   ; Igashira, Masayuki*; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Kamiyama, Takashi*; Kino, Koichi*; Kiyanagi, Yoshiaki*

The prompt rays from the neutron capture reactions by Zr and Zr were measured. A neutron time-of-flight (TOF) method was adopted with a 4 Ge spectrometer installed at the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) in the J-PARC Material and Life science experimental Facility (MLF). The -ray pulse-height spectra corresponding to the 292-eV resonance of Zr and the 301-eV resonance of Zr were obtained by gating on the TOF regions, respectively. The relative intensities of those transitions were derived. Moreover, we have demonstrated the nuclide discrimination technique by identifying Zr resonances (isotopic composition of 5.3%) in the measurement of Zr sample. This technique can be applicable to the neutron capture measurement for a small amount of sample expected in case of long lived fission products (LLFPs) such as Zr.