Breakup mechanism in the 27 Al (14 N, X) reaction

Available as short communication only. The present contribution is based on measurements performed on 27 Al (14 N,X) reaction at 116 MeV and 55 MeV bombarding energies. Self supported 27 Al foils 470 μg/cm2 thick were used as targets. The reaction products with charges ranging between 3 and 13 were identified by use of ΔE(gas)-E detectors filled with high purity Krypton at pressures 60-150 m bars. The results obtained at 116 MeV are in good agreement with three-body final-state calculations, using a formalism based on the deuteron breakup model of Serber, and developed by Matsuoka and al. and by Tabor and al. for heavier systems (see M. Petrascu et al. Z. Phys. A345 (1993) 395). In these calculations it is assumed that the target behaves as a spectator during the interaction and only provides a field for the projectile breakup. During the interaction the target can be excited but remains intact, while the projectile breaks up into 2 fragments, leaving a three body final state. The results obtained at the lower energy, 55 MeV, could be also described by a breakup model, but they are rather compatible with a two-body final-state mechanism. (Author) 1 Fig., 2 Refs