CHANGING SOURCE CHARACTERISTICS DURING MULTIFRAGMENT DECAY

The spatial-temporal extent of the emitting system for central collisi ons in Kr-84 + Au-197 at E/A = 35, 55, and 70 MeV is probed using frag ment-fragment velocity correlation functions. Selection on fragment pa irs of high velocity yields a stronger fragment-fragment Coulomb inter action than for inclusive fragment pairs. This result is consistent wi th fragment emission from a source of decreased spatial-temporal exten t. The universality of this association and the effect of different se lection criteria are explored. The sensitivity of the spatial-temporal extent deduced by the correlation function technique to measurement u ncertainties, assumed source characteristics, and rotational effects i s assessed.