ENERGY DISTRIBUTION OF Be$sup 8$ IN C$sup 12$ THREE $alpha$ PARTICLE DECAY UNDER THE ACTION OF PROTONS AND NEUTRONS

The mechanism of C/sup 12/ yields 3 alpha decay under the action of 8.5- and 19-Mev neutrons and 15- to 30-Mev protons was studied. The probability of the intermediate Be/sup 8/ nucleus in the C/sup 12/ yields B/sup 8/ + alpha yields 3 alpha cascade and resonance interaction of two alpha particles in the finite state is analyzed, as well as the existence of the wide Be/sup 8/ level with center at 11.7 Mev and levels distributed between 3 and 11 Mev. The reactions C/sup 12/(n,n3 alpha ) in three-prong and C/sup 12/(p,p'3 alpha ) in five-prong stars in photoemulsion, irradiated by variable energy neutrons and protons, were observed. The energy distributions of alpha particles in the center-of-mass system of C/sup 13/ in C/sup 12/(n,n'3 alpha ) reaction were plotted for one group of incident neutron energies and for four groups of alpha particles in the center-of-mass of N/sup 13/ in C/sup 12/(p,p', 3 alpha ) reaction. In spite of the variations of incident nucleon energy from 14 to 30 Mev, the maximum of the alpha -particle energy distributions remains at approximately 3 Mev. Energy distributions for the B/sup 8/ in C/sup 12/(n,n', 3 alpha ) at E/sub n/ =more » 14 to 19 Mev and C/sup 12/(p,p', 3 alpha ) at B/sub p/ = 15 to 30 Mev are calculated with assumption of simultaneous decay. The obtained data indicate the probability of C/sup 12/ decay into three alpha particles with a strong resonance interaction of finite state particles. (R.V.J.)« less