Monte Carlo Modeling Of Production Of Three Alpha-Particles In Low Energy N+C-12 Interactions

To describe n +C-12 interactions with production of three alpha-particles at incident neutron kinetic energy of 14 MeV in a nuclear (photo) emulsion, a Monte Carlo model is proposed for four channels of decay of an excited carbon-12 nucleus into three alpha-particles. The Monte Carlo calculation results describe well the experimental data on the distribution of the angle between the three-dimensional momenta of all pairs of alpha-particles in a collision event, on the distribution of the angle between the projections of the momentum vectors of all pairs of alpha-particles in collision event on each of the coordinate planes, on the distribution of the sum of the kinetic energies of all pairs of alpha-particles in a collision event, and the distribution of projections of the momenta of alpha-particles on the coordinate planes. The best agreement of the Monte Carlo model results with the experimental data is achieved if the direct decay C-12*-> 3 alpha and decay through the formation of an intermediate beryllium nucleus C-12*-> alpha + Be-8*-> 3 alpha are generated with equal probabilities, while the excitation energies of 3.04 MeV, 1.04 MeV, and 0.1 MeV for the beryllium nucleus are generated with relative weights of 75%, 15%, and 10%, respectively.