EVOLUTION OF FRAGMENT-FRAGMENT CORRELATIONS IN REACTIONS OF AU-197 AND AG-107, AG-109 WITH AR-40 FROM 7A TO 34A MEV

In-plane and out-of-plane angular correlations have been measured between fragments of Z > 3, Li fragments, He-3, He-4 and H-1, H-2, H-3. The changing patterns for Ar-40 induced reactions of 7 A, 17 A, 27 A, and 34 A MeV give an overview of the decreasing importance of mass-symmetric fissionlike reactions at the expense of a broad range of more mass-asymmetric breakups. Evidence is given that these fragments come from a central collision group of reactions that have similar violence and from which many combinations of fragments and particles are ejected. Very similar-azimuthal angular correlations are observed for particles with a Li fragment and for particles with a pair of heavier fragments (Z > 3). This similarity suggests comparable strengths of association with the reaction plane for single Li fragments and for fragment pairs of Z > 3. Azimuthal angular correlations for Li-Li pairs exhibit distinct asymmetries; their interpretation via trajectory-model calculations indicates mean delay times of almost-equal-to 5 x 10(-22) S.