Development of correction methods for the time-of-flight prompt -ray analysis at ANNRI

Huang, M.; Toh, Yosuke   ; Ebihara, Mitsuru*; Kimura, Atsushi   ; Nakamura, Shoji  

The J-PARC Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) has been available for the time-of-flight (TOF) prompt -ray analysis. However, it is not entirely clear on the specific relationship between the number of detected events and the sample weight. In this study, a set of standard Fe and Ag samples were measured to examine the factors which affect the counts and TOF counts. It is found that the main contributing factors are live-time ratio of the data acquisition system (), data acquisition efficiency during the live time (), neutron attenuation (NA) and -ray attenuation (GA). A 5.3-kHz random-pulse generator is used for the determination of . is calibrated with an empirical formula. Simulation models are built for the evaluations of NA and GA by the PHITS program. With the present method, the values of corrected counts are accurately proportional to the sample weights.