Measurement and analysis of neutron-induced alpha particle emission double-differential cross section of carbon at 14.2 MeV

Kondo, Keitaro; Murata, Isao*; Ochiai, Kentaro; Kubota, Naoyoshi*; Miyamaru, Hiroyuki*; Konno, Chikara  ; Nishitani, Takeo

We carried out a detailed measurement of neutron induced -particle emission double-differential cross-section of carbon at 14.2 MeV, for which there were few measured data in spite of its importance in many applications. The obtained cross-section for the C(n,)Be reaction agreed well with previous experiments and evaluated nuclear data. The obtained angular-differential cross-section of the C(n,n'+3) reaction for -particles showed a strong forward-peaked distribution that suggested significant contribution of the direct reaction process to the 3 breakup. We attempted to calculate the emitted particle spectra by means of a Monte Carlo method and estimate the branching ratio of the channels which contribute to the C(n,n'+3) reaction. As a result, it was found that the C(n,)Be* channels play an important role in generating the experimental double-differential cross-section both of emitted -particles and neutrons. The estimated ratio of the C(n,)Be* channels was around 40%, somewhat larger than those evaluated in previous studies.