SAIP 2011

Quasi-elastic binary breakup in the interaction of ¹²C with ¹²C, ⁹³Nb and ¹⁹⁷Au at 400 MeV incident energy

13 Jul 2011, 12:00

15m

Acro8

Oral Presentation Track B - Nuclear, Particle and Radiation Physics NPRP

Speaker

Mr Joele Mira (University of Stellenbosch/iThemba LABS)

Description

In heavy ion reactions the emission of Intermediate Mass Fragments (IMFs) at forward angles is dominated by the direct break-up process. To improve our understanding of this process in the reaction mechanisms involving the interaction of light projectiles with light to heavy target nuclei, a coincidence measurement was performed at iThemba LABS. Standard ΔE-E detector telescopes were used to identify and measure the energies of the of the correlated ⁸Be and alpha particles produced in the binary break-up of ¹²C projectiles at an incident energy of 400 MeV. While the ⁸Be fragments were detected in their ground state at a fixed angle of 9º, the correlated alpha particles were measured on the opposite side of the beam, covering an angular range from 16º to 26º. Two dimensional energy spectra were generated for each alpha-particle angle in order to distinguish quasi-elastic events from inelastic break-up events. These spectra also allowed to identify events originating from the interaction of the ¹²C beam with an H contaminant on the target foils and to subsequently correct for these events in the extraction of angular distributions for alpha particles in coincidence with quasi-elastic ⁸Be particles. The angular distributions obtained from the interaction of ¹²C with ⁹³Nb and ¹⁹⁷Au show a smooth decreasing trend with respect to the alpha-particle angle, which suggests that the binary break-up of ¹²C seems to be independent of the target nucleus. A deviation from this trend is however observed for the ¹²C target. As a first attempt to interpret these results a comparison between the measured angular distributions and GEANT4 simulations will be presented.