Interaction of Neutrons with⁹Be at 14.6 MeV — The Four-Body Breakup 2n+ 2α

Experimental study on breakup reaction of beryllium and carbon induced with 14-MeV neutrons based on emitted charged-particle measurements

“…There is no evaluated DDX which can be compared with our data directly. In our obtained DDX, obvious peaks corresponding to the 12 C(n,α 0 ) 9 Be (Ground State) and 12 C(n,α) 9 Be* (2.43 MeV) reactions are clearly identified. The contribution of 9 Be* (4.7 MeV) might exist.…”

“…There has been an only previous measurement by Ferenc et al [9], which was, however, a relative measurement and measured energy range was not so wide. Hence, our data is the only existing detailed experiment.…”

“…Figures 2 and 3 show the obtained DDX at 20 and 40deg and comparison with evaluated nuclear data taken from JENDL-3.3 and ENDF/B-VI.8 [10]. In the measured DDX, two peaks corresponding to the 9 Be(n,α 0 ) 6 He (ground state) and 9 Be(n,α 1 ) 6 He* (1.8 MeV) reactions are identified. The evaluated libraries significantly underestimate the higher energy part of DDX at 20 deg while these well agree with each other at 40 deg.…”

“…The anticoincidence spectrum above those threshold energies for protons and tritons hence originates only from α-particles or particles heavier than α-particles. In the present measurement, recoiling beryllium or carbon and 9 Be particles emitted via the 12 C(n,α) 9 Be reaction cannot be negligible and their contributions are calculated and subtracted. As a result, the measurement of α-particles with a minimum energy of around 1 MeV was successfully realized.…”

“…[1]. In the calculation, simply 2-body sequential decays via excited states of 12 C, 9 Be and 6 He and the 3-body simultaneous breakup with a pure phase space were considered. Decay modes for 8 Be* and 5 He* from the excited nuclei were adopted according to refs.…”