INVESTIGATION OF THE SEQUENTIAL BREAK-UP MODE LI-6-]LI-6-STAR(3-1+)-]ALPHA+D OF 156-MEV LI-6 PROJECTILES ON PB-208 IN THE VERY FORWARD ANGULAR HEMISPHERE

The sequential break-up of 156 MeV Li-6 projectiles colliding with Pb-208 has been investigated in the very forward angular hemisphere in order to explore the role of the Coulomb and nuclear interaction in inducing projectile break-up processes. The experiments use the Karlsruhe spectrograph "Little John" with a newly developed technique to detect efficiently break-up pairs of alpha-particles and deuterons emitted with small relative energies and within a small opening angle. The observed differential cross section for the projectile excitation Li-6 --> Li-6* (I = 3(1)+) has been analysed (together with forward elastic scattering) by a coupled channel approach, and various sensitivities to the nuclear potential and other ingredients have been studied. We conclude, that in the angular region below half the grazing angle the excitation is completely due to the Coulomb force. This feature is a basis for an application of the disintegration approach for studies of radiative capture cross section of astrophysical interest.