The mechanism of the reaction12C(n, n )3 at 14.18 MeV neutron energy

A detailed study in photoemulsions of the reaction 12 C(n, ń)3α excited by neutrons of energy 14.18 ± 0.05 MeV has provided information on the reaction mechanism. About 50% of the events are attributed to the mode 12 C(n, ń) 12 C*, 12 C*(α) 8 Be* -> 2α, most of the remainder being due to 12 C(n, α) 9 Be*, 9 Be*(n) 8 Be* -> 2α and 9 Be*(α) 5 He*(n)α. However, the reaction 12 C(n, 5 He*) 8 Be* cannot be excluded. Four-body break-up, suggested by some authors, is unnecessary to explain the results. The 10.8 and 11.8 MeV states of 12 C occur in the (n, ń) reaction and the data allow the assignment 1 - to the former and suggest 2 - for the latter.