Fragment production in intermediate-energy heavy-ion reactions

The emission of fragments with A less than or equal to 14 has been studied in intermediate energy argon and neon-induced reactions. The energy spectra were observed to be approximately Maxwellian and the high energy region was fitted assuming emission from a single moving source. The source was found to move with a velocity intermediate between that of the projectile and the target, and its temperature was approximately independent of the mass of the emitted fragment, suggesting that complex fragments as well as light particles are emitted from a thermalized subsystem in the reaction. A quantum statistical model of the disassembly of the thermalized region was used to infer information about the entropy of the system from the observed fragment distribution. In addition, the light particle data were used to test two models for the collisions dynamics