12C formation: A classical quest in new light

Olof Tengblad; M. Alcorta; M. J. G. Borge; M. Cubero; M. Madurga; A. Perea; H. O. U. Fynbo; K. Riisager; O. Kirsebom; S. Hyldegaard; Björn Jonson; Göran Hugo Nyman; Thomas Nilsson; D.G. Diget; B. Fulton

doi:10.1063/1.3628391

12C formation: A classical quest in new light
Paper i proceeding, 2011

In this work we have studied the break‐up of 12C following the reactions 10B(3He,pααα) and 11B(3He,dααα). The study was performed at the 5 MV tandem in Madrid. The break‐up gives us information on excited states in 12C from the famous Hoyle state up to an energy of almost 18 MeV. Using a highly segmented experimental set‐up the simultaneous detection of the three alpha particles in coincidence with a proton or deuteron respectively made possible a full kinematic reconstruction of the break‐up. On the basis of the energies of the 3 α particles and their angular correlations it has been possible to determine the spin and parity of states for cases in which the assignment has been doubtful. Some of these levels will also de‐excite via electromagnetic emission. The comparison between the energy of proton that populate a state of 12C and the sum of the energies of the 3α emitted from the same state makes possible to determine the presence of electromagnetic disintegration (γ) to lower states within 12C followed by the 3α break‐up.

12C

tripple alpha process

particle spectroscopy

multi particle break-up