(d, α) reaktionen an leichten kernen

Abstract

The analysed beam from the Heidelberg cyclotron has been used to investigate (d, α) reactions on 24Mg, 25Mg and 28Si targets at incident beam energies between 11.45 und 12.1 MeV. Angular distributions of α-particles corresponding to the excitation of the lowest six to ten levels of the residual nuclei have been measured in the range between 15° and 165°. The data suggest a mixed direct and compound nucleus interaction mechanism. The latter seems to be predominant in the 25Mg(d, α) reaction. The angular distributions have been analysed by double pick-up theory where feasible. The (2 I+1) rule has been observed to hold for 25Mg(d, α) and to a lower degree of accuracy for 28Si(d, α). From the viewpoint of this rule it is suggested that the well-known 2.07 MeV level in 26Al is a doublet state as proposed earlier. The integrated cross-sections of various α-particle groups from the (d, α) reactions on 9Be, 14N, 16O, 31P and 32S have also been measured. A pronounced odd-even effect has been observed not only for the transitions to the ground states but also for the transitions to the excited states up to about 3 MeV.