Non-Instantaneous Breakup of Excited Nuclear Systems
Recent experimental evidence indicates that bombardment of a target nucleus with intermediate energy heavy-ions [1, 2, 3] or high energy light-ions  can result in decay of the excited nuclear system into multiple intermediate mass fragments (IMFs:3 ≤ Z ≤ 20). Such a multifragment final state might arise due to either dynamical surface instabilities of the composite system, or alternatively from volume instabilities [5, 6]. While decay driven by surface instabilities (Rayleigh instabilities) might provide insight into the dynamics of the collision process, volume instabilities could yield information regarding the phase diagram of nuclear matter. Trajectories in the temperature density plane could depend sensitively on the dissipation and deposition of excitation energy. Recent experimental results have linked multifragment decays to a phase transition in finite nuclear systems . This approach, however, avoids the issue of the importance of the collision dynamics. Do all the fragments arise instantaneously from an unstable homogeneous source [8, 9] or are the fragments emitted as the system de-excites and the source characteristics (excitation, charge, radius) change [10, 11]? The present work attempts to distinguish between these two scenarios.
KeywordsCentral Collision Emission Time Fragment Pair Volume Instability Intermediate Mass Fragment
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