Measurement of the thermal neutron capture-cross section of Ir at ANNRI MLF J-PARC

Patwary, K.; 瀬川 麻里子   ; 前田 亮  ; 藤 暢輔   ; 遠藤 駿典   ; 中村 詔司  ; Rovira Leveroni, G.   ; 木村 敦   

Patwary, K.; Segawa, Mariko; Maeda, Makoto; Toh, Yosuke; Endo, Shunsuke; Nakamura, Shoji; Rovira Leveroni, G.; Kimura, Atsushi

Thermal neutron capture cross-section for Ir, (E), is a prominent parameter in producing Ir radionuclide used in high-dose-rate brachytherapy. However, considerable discrepancies exist in past measurements using the activation method and a derived cross-section data calculation from positive resonance parameters of Ir, which were measured using the neutron time-of-flight (TOF) method. Therefore, for the first time, we aimed to measure the (E) accurately using the neutron TOF method. Experiments were performed using a pulsed neutron beam and a NaI(Tl) detector at the Accurate Neutron-Nucleus Reaction Measurement Instrument of the Materials and Life Science Experimental Facility in the J-PARC. The (E) was derived from the capture yield using the pulse height weighting technique. As a result, this study obtained the (E) as 949 80 b. The result agrees with some activation data and the evaluated nuclear data libraries, JENDL-5 and ENDF/B-VIII.0, within its uncertainty of 8.4%. This study provides a data reference for the (E) measurement using the neutron TOF method.