Experimental analysis for neutron multiplication by using reaction rate distribution in accelerator-driven system

Basic experiments are carried out in the Kyoto University Critical Assembly (KUCA) to study the nuclear characteristics of the accelerator-driven systems (ADS) and to establish a new neutron source for research. A method for measuring the neutron multiplication in the subcritical system is proposed by utilizing the reaction rate distribution obtained by the optical fiber detector. A comparison between the measured and calculated neutron multiplication shows agreement within a relative difference of 5% in most cases, through introducing certain correction factors.