Breakup of beryllium 7

For the ⁷Be (n,$\alpha$) ⁴He reaction endep calculates the energy available, namely, the sum of the energy from the mass difference plus the energy of the incident neutron. It apportions this energy equally between the two alphas and writes two files, one for the alpha as secondary particle ( $\tt yo$ = 6) and one for the alpha as residual nucleus ( $\tt yo$ = 16).