Measurement and Analysis of Neutron-Induced Alpha Particle Emission Double-Differential Cross Section of Carbon at 14.2 MeV

Abstract

We carried out a detailed measurement of the neutron-induced -particle emission double-differential cross section of carbon at 14.2 MeV, for which there are few measured data in spite of its importance in many applications. In our measurement, a superior S/N ratio, high angular/energy resolutions and a wide detection energy range were realized with a pencil DT neutron beam and a countertelescope system. The obtained cross section for the 12 C(n, 0 ) 9 Be (ground state) reaction agreed well with the results of previous experiments and evaluated nuclear data. The obtained angular-differential cross section of the 12 C(n,n 0 +3) reaction for -particles showed a strong forward-peaked distribution that suggested a significant contribution of the direct reaction process to the 3 breakup. We attempted to calculate the emitted particle spectra by a Monte Carlo method and estimate the branching ratio of the channels that contribute to the 12 C(n,n 0 +3) reaction. As a result, it was found that the 12 C(n,) 9 Be à channels play an important role in generating the experimental double-differential cross section both of emitted -particles and neutrons. The estimated ratio of the 12 C(n,) 9 Be à channels was approximately 40%, somewhat larger than those evaluated in previous studies.

Development of precise energy spectrum measurement technique for high-power pulsed X-ray sources for industrial use

“…This method is based on the Bayesian theorem and it has recently been applied to radiation measurements. For instance, in energy spectrum measurements of charged particles, correction of the energy loss in the sample is carried out using the spectrum-type Bayesian estimation method as an unfolding technique [6][7][8][9]. The specific features of the spectrum-type Bayesian estimation method are summarized as follows.…”