The circular polarization of γ-rays, following the 16O on 58Ni, 40Ar and 86Kr on Ag reactions

We have measured the circular polarization of the deexcitation γ-rays following the 16O on 58Ni, 40Ar and 86Kr on Ag reactions at incident energies of 100, 303(284) and 539 MeV, respectively. A symmetric set up of two inplane heavy-ion telescopes at theta sub(lab) = 350 and two polarimeters normal to the reaction plane has been used. For quasielastic reactions negative γ-polarizations with an average value of 20 to 50% are observed. This reflects the predominance of positive classical deflection angles in weakly damped grazing collisions. For strongly damped (deep inelastic) processes positive P sub(γ) values of +50, +25 and <+10%, respectively, demonstrate the predominance of negative deflection angles. (auth.)