6 alpha particle emission in the reaction N-13+B-11

The six-ct decay of Mg-24 has been studied via the reaction N-13+ B-11 at t wo beam energies, 29.5 MeV and if 45 MeV. Large detector arrays allowed thi s reaction to be studied with low intensity radioactive N-13 beam. The exci tation energy in the Mg-24* was in the region of the 46 MeV resonance in C- 12+C-12 scattering. From the six-a particles, events of interest were selec ted by associating two of the a particle pairs as the decay products of Be- 8. The c.m. energy spectra for two Be-8 + two alpha events have been extrac ted. The analysis revealed that most of these events originate from C-12(31 )- + C-12(31)-. The total cross section for these six-alpha events has been extracted at the two beam energies. [S0556-2813(99)06902-2].